leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity
ada8ce1530
linux/drivers/pci/pci.c
Lukas Wunner 2a4d2c4240 PCI: Make pci_wakeup_bus() & pci_bus_set_current_state() public 
There are PCI devices which are power-manageable by a nonstandard means,
such as a custom ACPI method.  One example are discrete GPUs in hybrid
graphics laptops, another are Thunderbolt controllers in Macs.

Such devices can't be put into D3cold with pci_set_power_state() because
pci_platform_power_transition() fails with -ENODEV.  Instead they're put
into D3hot by pci_set_power_state() and subsequently into D3cold by
invoking the nonstandard means.  However as a consequence the cached
current_state is incorrectly left at D3hot.

What we need to do is walk the hierarchy below such a PCI device on
powerdown and update the current_state to D3cold.  On powerup the PCI
device itself and the hierarchy below it is in D0uninitialized, so we
need to walk the hierarchy again and wake all devices, causing them to
be put into D0active and then letting them autosuspend as they see fit.

To this end make pci_wakeup_bus() & pci_bus_set_current_state() public
so PCI drivers don't have to reinvent the wheel.

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://patchwork.freedesktop.org/patch/msgid/2962443259e7faec577274b4ef8c54aad66f9a94.1520068884.git.lukas@wunner.de
2018-03-13 22:57:36 +01:00

5704 lines
148 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0
/*
* PCI Bus Services, see include/linux/pci.h for further explanation.
*
* Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter,
* David Mosberger-Tang
*
* Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz>
*/
#include <linux/acpi.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/dmi.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_pci.h>
#include <linux/pci.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/log2.h>
#include <linux/pci-aspm.h>
#include <linux/pm_wakeup.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/pm_runtime.h>
#include <linux/pci_hotplug.h>
#include <linux/vmalloc.h>
#include <linux/pci-ats.h>
#include <asm/setup.h>
#include <asm/dma.h>
#include <linux/aer.h>
#include "pci.h"
const char *pci_power_names[] = {
"error", "D0", "D1", "D2", "D3hot", "D3cold", "unknown",
};
EXPORT_SYMBOL_GPL(pci_power_names);
int isa_dma_bridge_buggy;
EXPORT_SYMBOL(isa_dma_bridge_buggy);
int pci_pci_problems;
EXPORT_SYMBOL(pci_pci_problems);
unsigned int pci_pm_d3_delay;
static void pci_pme_list_scan(struct work_struct *work);
static LIST_HEAD(pci_pme_list);
static DEFINE_MUTEX(pci_pme_list_mutex);
static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan);
struct pci_pme_device {
struct list_head list;
struct pci_dev *dev;
};
#define PME_TIMEOUT 1000 /* How long between PME checks */
static void pci_dev_d3_sleep(struct pci_dev *dev)
{
unsigned int delay = dev->d3_delay;
if (delay < pci_pm_d3_delay)
delay = pci_pm_d3_delay;
if (delay)
msleep(delay);
}
#ifdef CONFIG_PCI_DOMAINS
int pci_domains_supported = 1;
#endif
#define DEFAULT_CARDBUS_IO_SIZE (256)
#define DEFAULT_CARDBUS_MEM_SIZE (64*1024*1024)
/* pci=cbmemsize=nnM,cbiosize=nn can override this */
unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;
unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
#define DEFAULT_HOTPLUG_IO_SIZE (256)
#define DEFAULT_HOTPLUG_MEM_SIZE (2*1024*1024)
/* pci=hpmemsize=nnM,hpiosize=nn can override this */
unsigned long pci_hotplug_io_size = DEFAULT_HOTPLUG_IO_SIZE;
unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;
#define DEFAULT_HOTPLUG_BUS_SIZE 1
unsigned long pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE;
enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_DEFAULT;
/*
* The default CLS is used if arch didn't set CLS explicitly and not
* all pci devices agree on the same value. Arch can override either
* the dfl or actual value as it sees fit. Don't forget this is
* measured in 32-bit words, not bytes.
*/
u8 pci_dfl_cache_line_size = L1_CACHE_BYTES >> 2;
u8 pci_cache_line_size;
/*
* If we set up a device for bus mastering, we need to check the latency
* timer as certain BIOSes forget to set it properly.
*/
unsigned int pcibios_max_latency = 255;
/* If set, the PCIe ARI capability will not be used. */
static bool pcie_ari_disabled;
/* Disable bridge_d3 for all PCIe ports */
static bool pci_bridge_d3_disable;
/* Force bridge_d3 for all PCIe ports */
static bool pci_bridge_d3_force;
static int __init pcie_port_pm_setup(char *str)
{
if (!strcmp(str, "off"))
pci_bridge_d3_disable = true;
else if (!strcmp(str, "force"))
pci_bridge_d3_force = true;
return 1;
}
__setup("pcie_port_pm=", pcie_port_pm_setup);
/**
* pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
* @bus: pointer to PCI bus structure to search
*
* Given a PCI bus, returns the highest PCI bus number present in the set
* including the given PCI bus and its list of child PCI buses.
*/
unsigned char pci_bus_max_busnr(struct pci_bus *bus)
{
struct pci_bus *tmp;
unsigned char max, n;
max = bus->busn_res.end;
list_for_each_entry(tmp, &bus->children, node) {
n = pci_bus_max_busnr(tmp);
if (n > max)
max = n;
}
return max;
}
EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
#ifdef CONFIG_HAS_IOMEM
void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
{
struct resource *res = &pdev->resource[bar];
/*
* Make sure the BAR is actually a memory resource, not an IO resource
*/
if (res->flags & IORESOURCE_UNSET || !(res->flags & IORESOURCE_MEM)) {
pci_warn(pdev, "can't ioremap BAR %d: %pR\n", bar, res);
return NULL;
}
return ioremap_nocache(res->start, resource_size(res));
}
EXPORT_SYMBOL_GPL(pci_ioremap_bar);
void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
{
/*
* Make sure the BAR is actually a memory resource, not an IO resource
*/
if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
WARN_ON(1);
return NULL;
}
return ioremap_wc(pci_resource_start(pdev, bar),
pci_resource_len(pdev, bar));
}
EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar);
#endif
static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
u8 pos, int cap, int *ttl)
{
u8 id;
u16 ent;
pci_bus_read_config_byte(bus, devfn, pos, &pos);
while ((*ttl)--) {
if (pos < 0x40)
break;
pos &= ~3;
pci_bus_read_config_word(bus, devfn, pos, &ent);
id = ent & 0xff;
if (id == 0xff)
break;
if (id == cap)
return pos;
pos = (ent >> 8);
}
return 0;
}
static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn,
u8 pos, int cap)
{
int ttl = PCI_FIND_CAP_TTL;
return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl);
}
int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
{
return __pci_find_next_cap(dev->bus, dev->devfn,
pos + PCI_CAP_LIST_NEXT, cap);
}
EXPORT_SYMBOL_GPL(pci_find_next_capability);
static int __pci_bus_find_cap_start(struct pci_bus *bus,
unsigned int devfn, u8 hdr_type)
{
u16 status;
pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
if (!(status & PCI_STATUS_CAP_LIST))
return 0;
switch (hdr_type) {
case PCI_HEADER_TYPE_NORMAL:
case PCI_HEADER_TYPE_BRIDGE:
return PCI_CAPABILITY_LIST;
case PCI_HEADER_TYPE_CARDBUS:
return PCI_CB_CAPABILITY_LIST;
}
return 0;
}
/**
* pci_find_capability - query for devices' capabilities
* @dev: PCI device to query
* @cap: capability code
*
* Tell if a device supports a given PCI capability.
* Returns the address of the requested capability structure within the
* device's PCI configuration space or 0 in case the device does not
* support it. Possible values for @cap:
*
* %PCI_CAP_ID_PM Power Management
* %PCI_CAP_ID_AGP Accelerated Graphics Port
* %PCI_CAP_ID_VPD Vital Product Data
* %PCI_CAP_ID_SLOTID Slot Identification
* %PCI_CAP_ID_MSI Message Signalled Interrupts
* %PCI_CAP_ID_CHSWP CompactPCI HotSwap
* %PCI_CAP_ID_PCIX PCI-X
* %PCI_CAP_ID_EXP PCI Express
*/
int pci_find_capability(struct pci_dev *dev, int cap)
{
int pos;
pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
if (pos)
pos = __pci_find_next_cap(dev->bus, dev->devfn, pos, cap);
return pos;
}
EXPORT_SYMBOL(pci_find_capability);
/**
* pci_bus_find_capability - query for devices' capabilities
* @bus: the PCI bus to query
* @devfn: PCI device to query
* @cap: capability code
*
* Like pci_find_capability() but works for pci devices that do not have a
* pci_dev structure set up yet.
*
* Returns the address of the requested capability structure within the
* device's PCI configuration space or 0 in case the device does not
* support it.
*/
int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
{
int pos;
u8 hdr_type;
pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
pos = __pci_bus_find_cap_start(bus, devfn, hdr_type & 0x7f);
if (pos)
pos = __pci_find_next_cap(bus, devfn, pos, cap);
return pos;
}
EXPORT_SYMBOL(pci_bus_find_capability);
/**
* pci_find_next_ext_capability - Find an extended capability
* @dev: PCI device to query
* @start: address at which to start looking (0 to start at beginning of list)
* @cap: capability code
*
* Returns the address of the next matching extended capability structure
* within the device's PCI configuration space or 0 if the device does
* not support it. Some capabilities can occur several times, e.g., the
* vendor-specific capability, and this provides a way to find them all.
*/
int pci_find_next_ext_capability(struct pci_dev *dev, int start, int cap)
{
u32 header;
int ttl;
int pos = PCI_CFG_SPACE_SIZE;
/* minimum 8 bytes per capability */
ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
if (dev->cfg_size <= PCI_CFG_SPACE_SIZE)
return 0;
if (start)
pos = start;
if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
return 0;
/*
* If we have no capabilities, this is indicated by cap ID,
* cap version and next pointer all being 0.
*/
if (header == 0)
return 0;
while (ttl-- > 0) {
if (PCI_EXT_CAP_ID(header) == cap && pos != start)
return pos;
pos = PCI_EXT_CAP_NEXT(header);
if (pos < PCI_CFG_SPACE_SIZE)
break;
if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
break;
}
return 0;
}
EXPORT_SYMBOL_GPL(pci_find_next_ext_capability);
/**
* pci_find_ext_capability - Find an extended capability
* @dev: PCI device to query
* @cap: capability code
*
* Returns the address of the requested extended capability structure
* within the device's PCI configuration space or 0 if the device does
* not support it. Possible values for @cap:
*
* %PCI_EXT_CAP_ID_ERR Advanced Error Reporting
* %PCI_EXT_CAP_ID_VC Virtual Channel
* %PCI_EXT_CAP_ID_DSN Device Serial Number
* %PCI_EXT_CAP_ID_PWR Power Budgeting
*/
int pci_find_ext_capability(struct pci_dev *dev, int cap)
{
return pci_find_next_ext_capability(dev, 0, cap);
}
EXPORT_SYMBOL_GPL(pci_find_ext_capability);
static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap)
{
int rc, ttl = PCI_FIND_CAP_TTL;
u8 cap, mask;
if (ht_cap == HT_CAPTYPE_SLAVE || ht_cap == HT_CAPTYPE_HOST)
mask = HT_3BIT_CAP_MASK;
else
mask = HT_5BIT_CAP_MASK;
pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos,
PCI_CAP_ID_HT, &ttl);
while (pos) {
rc = pci_read_config_byte(dev, pos + 3, &cap);
if (rc != PCIBIOS_SUCCESSFUL)
return 0;
if ((cap & mask) == ht_cap)
return pos;
pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn,
pos + PCI_CAP_LIST_NEXT,
PCI_CAP_ID_HT, &ttl);
}
return 0;
}
/**
* pci_find_next_ht_capability - query a device's Hypertransport capabilities
* @dev: PCI device to query
* @pos: Position from which to continue searching
* @ht_cap: Hypertransport capability code
*
* To be used in conjunction with pci_find_ht_capability() to search for
* all capabilities matching @ht_cap. @pos should always be a value returned
* from pci_find_ht_capability().
*
* NB. To be 100% safe against broken PCI devices, the caller should take
* steps to avoid an infinite loop.
*/
int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap)
{
return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap);
}
EXPORT_SYMBOL_GPL(pci_find_next_ht_capability);
/**
* pci_find_ht_capability - query a device's Hypertransport capabilities
* @dev: PCI device to query
* @ht_cap: Hypertransport capability code
*
* Tell if a device supports a given Hypertransport capability.
* Returns an address within the device's PCI configuration space
* or 0 in case the device does not support the request capability.
* The address points to the PCI capability, of type PCI_CAP_ID_HT,
* which has a Hypertransport capability matching @ht_cap.
*/
int pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
{
int pos;
pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
if (pos)
pos = __pci_find_next_ht_cap(dev, pos, ht_cap);
return pos;
}
EXPORT_SYMBOL_GPL(pci_find_ht_capability);
/**
* pci_find_parent_resource - return resource region of parent bus of given region
* @dev: PCI device structure contains resources to be searched
* @res: child resource record for which parent is sought
*
* For given resource region of given device, return the resource
* region of parent bus the given region is contained in.
*/
struct resource *pci_find_parent_resource(const struct pci_dev *dev,
struct resource *res)
{
const struct pci_bus *bus = dev->bus;
struct resource *r;
int i;
pci_bus_for_each_resource(bus, r, i) {
if (!r)
continue;
if (resource_contains(r, res)) {
/*
* If the window is prefetchable but the BAR is
* not, the allocator made a mistake.
*/
if (r->flags & IORESOURCE_PREFETCH &&
!(res->flags & IORESOURCE_PREFETCH))
return NULL;
/*
* If we're below a transparent bridge, there may
* be both a positively-decoded aperture and a
* subtractively-decoded region that contain the BAR.
* We want the positively-decoded one, so this depends
* on pci_bus_for_each_resource() giving us those
* first.
*/
return r;
}
}
return NULL;
}
EXPORT_SYMBOL(pci_find_parent_resource);
/**
* pci_find_resource - Return matching PCI device resource
* @dev: PCI device to query
* @res: Resource to look for
*
* Goes over standard PCI resources (BARs) and checks if the given resource
* is partially or fully contained in any of them. In that case the
* matching resource is returned, %NULL otherwise.
*/
struct resource *pci_find_resource(struct pci_dev *dev, struct resource *res)
{
int i;
for (i = 0; i < PCI_ROM_RESOURCE; i++) {
struct resource *r = &dev->resource[i];
if (r->start && resource_contains(r, res))
return r;
}
return NULL;
}
EXPORT_SYMBOL(pci_find_resource);
/**
* pci_find_pcie_root_port - return PCIe Root Port
* @dev: PCI device to query
*
* Traverse up the parent chain and return the PCIe Root Port PCI Device
* for a given PCI Device.
*/
struct pci_dev *pci_find_pcie_root_port(struct pci_dev *dev)
{
struct pci_dev *bridge, *highest_pcie_bridge = dev;
bridge = pci_upstream_bridge(dev);
while (bridge && pci_is_pcie(bridge)) {
highest_pcie_bridge = bridge;
bridge = pci_upstream_bridge(bridge);
}
if (pci_pcie_type(highest_pcie_bridge) != PCI_EXP_TYPE_ROOT_PORT)
return NULL;
return highest_pcie_bridge;
}
EXPORT_SYMBOL(pci_find_pcie_root_port);
/**
* pci_wait_for_pending - wait for @mask bit(s) to clear in status word @pos
* @dev: the PCI device to operate on
* @pos: config space offset of status word
* @mask: mask of bit(s) to care about in status word
*
* Return 1 when mask bit(s) in status word clear, 0 otherwise.
*/
int pci_wait_for_pending(struct pci_dev *dev, int pos, u16 mask)
{
int i;
/* Wait for Transaction Pending bit clean */
for (i = 0; i < 4; i++) {
u16 status;
if (i)
msleep((1 << (i - 1)) * 100);
pci_read_config_word(dev, pos, &status);
if (!(status & mask))
return 1;
}
return 0;
}
/**
* pci_restore_bars - restore a device's BAR values (e.g. after wake-up)
* @dev: PCI device to have its BARs restored
*
* Restore the BAR values for a given device, so as to make it
* accessible by its driver.
*/
static void pci_restore_bars(struct pci_dev *dev)
{
int i;
for (i = 0; i < PCI_BRIDGE_RESOURCES; i++)
pci_update_resource(dev, i);
}
static const struct pci_platform_pm_ops *pci_platform_pm;
int pci_set_platform_pm(const struct pci_platform_pm_ops *ops)
{
if (!ops->is_manageable || !ops->set_state || !ops->get_state ||
!ops->choose_state || !ops->set_wakeup || !ops->need_resume)
return -EINVAL;
pci_platform_pm = ops;
return 0;
}
static inline bool platform_pci_power_manageable(struct pci_dev *dev)
{
return pci_platform_pm ? pci_platform_pm->is_manageable(dev) : false;
}
static inline int platform_pci_set_power_state(struct pci_dev *dev,
pci_power_t t)
{
return pci_platform_pm ? pci_platform_pm->set_state(dev, t) : -ENOSYS;
}
static inline pci_power_t platform_pci_get_power_state(struct pci_dev *dev)
{
return pci_platform_pm ? pci_platform_pm->get_state(dev) : PCI_UNKNOWN;
}
static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev)
{
return pci_platform_pm ?
pci_platform_pm->choose_state(dev) : PCI_POWER_ERROR;
}
static inline int platform_pci_set_wakeup(struct pci_dev *dev, bool enable)
{
return pci_platform_pm ?
pci_platform_pm->set_wakeup(dev, enable) : -ENODEV;
}
static inline bool platform_pci_need_resume(struct pci_dev *dev)
{
return pci_platform_pm ? pci_platform_pm->need_resume(dev) : false;
}
/**
* pci_raw_set_power_state - Use PCI PM registers to set the power state of
* given PCI device
* @dev: PCI device to handle.
* @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
*
* RETURN VALUE:
* -EINVAL if the requested state is invalid.
* -EIO if device does not support PCI PM or its PM capabilities register has a
* wrong version, or device doesn't support the requested state.
* 0 if device already is in the requested state.
* 0 if device's power state has been successfully changed.
*/
static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
{
u16 pmcsr;
bool need_restore = false;
/* Check if we're already there */
if (dev->current_state == state)
return 0;
if (!dev->pm_cap)
return -EIO;
if (state < PCI_D0 || state > PCI_D3hot)
return -EINVAL;
/* Validate current state:
* Can enter D0 from any state, but if we can only go deeper
* to sleep if we're already in a low power state
*/
if (state != PCI_D0 && dev->current_state <= PCI_D3cold
&& dev->current_state > state) {
pci_err(dev, "invalid power transition (from state %d to %d)\n",
dev->current_state, state);
return -EINVAL;
}
/* check if this device supports the desired state */
if ((state == PCI_D1 && !dev->d1_support)
|| (state == PCI_D2 && !dev->d2_support))
return -EIO;
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
/* If we're (effectively) in D3, force entire word to 0.
* This doesn't affect PME_Status, disables PME_En, and
* sets PowerState to 0.
*/
switch (dev->current_state) {
case PCI_D0:
case PCI_D1:
case PCI_D2:
pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
pmcsr |= state;
break;
case PCI_D3hot:
case PCI_D3cold:
case PCI_UNKNOWN: /* Boot-up */
if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
&& !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
need_restore = true;
/* Fall-through: force to D0 */
default:
pmcsr = 0;
break;
}
/* enter specified state */
pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
/* Mandatory power management transition delays */
/* see PCI PM 1.1 5.6.1 table 18 */
if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
pci_dev_d3_sleep(dev);
else if (state == PCI_D2 || dev->current_state == PCI_D2)
udelay(PCI_PM_D2_DELAY);
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
if (dev->current_state != state && printk_ratelimit())
pci_info(dev, "Refused to change power state, currently in D%d\n",
dev->current_state);
/*
* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
* INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
* from D3hot to D0 _may_ perform an internal reset, thereby
* going to "D0 Uninitialized" rather than "D0 Initialized".
* For example, at least some versions of the 3c905B and the
* 3c556B exhibit this behaviour.
*
* At least some laptop BIOSen (e.g. the Thinkpad T21) leave
* devices in a D3hot state at boot. Consequently, we need to
* restore at least the BARs so that the device will be
* accessible to its driver.
*/
if (need_restore)
pci_restore_bars(dev);
if (dev->bus->self)
pcie_aspm_pm_state_change(dev->bus->self);
return 0;
}
/**
* pci_update_current_state - Read power state of given device and cache it
* @dev: PCI device to handle.
* @state: State to cache in case the device doesn't have the PM capability
*
* The power state is read from the PMCSR register, which however is
* inaccessible in D3cold. The platform firmware is therefore queried first
* to detect accessibility of the register. In case the platform firmware
* reports an incorrect state or the device isn't power manageable by the
* platform at all, we try to detect D3cold by testing accessibility of the
* vendor ID in config space.
*/
void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
{
if (platform_pci_get_power_state(dev) == PCI_D3cold ||
!pci_device_is_present(dev)) {
dev->current_state = PCI_D3cold;
} else if (dev->pm_cap) {
u16 pmcsr;
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
} else {
dev->current_state = state;
}
}
/**
* pci_power_up - Put the given device into D0 forcibly
* @dev: PCI device to power up
*/
void pci_power_up(struct pci_dev *dev)
{
if (platform_pci_power_manageable(dev))
platform_pci_set_power_state(dev, PCI_D0);
pci_raw_set_power_state(dev, PCI_D0);
pci_update_current_state(dev, PCI_D0);
}
/**
* pci_platform_power_transition - Use platform to change device power state
* @dev: PCI device to handle.
* @state: State to put the device into.
*/
static int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
{
int error;
if (platform_pci_power_manageable(dev)) {
error = platform_pci_set_power_state(dev, state);
if (!error)
pci_update_current_state(dev, state);
} else
error = -ENODEV;
if (error && !dev->pm_cap) /* Fall back to PCI_D0 */
dev->current_state = PCI_D0;
return error;
}
/**
* pci_wakeup - Wake up a PCI device
* @pci_dev: Device to handle.
* @ign: ignored parameter
*/
static int pci_wakeup(struct pci_dev *pci_dev, void *ign)
{
pci_wakeup_event(pci_dev);
pm_request_resume(&pci_dev->dev);
return 0;
}
/**
* pci_wakeup_bus - Walk given bus and wake up devices on it
* @bus: Top bus of the subtree to walk.
*/
void pci_wakeup_bus(struct pci_bus *bus)
{
if (bus)
pci_walk_bus(bus, pci_wakeup, NULL);
}
/**
* __pci_start_power_transition - Start power transition of a PCI device
* @dev: PCI device to handle.
* @state: State to put the device into.
*/
static void __pci_start_power_transition(struct pci_dev *dev, pci_power_t state)
{
if (state == PCI_D0) {
pci_platform_power_transition(dev, PCI_D0);
/*
* Mandatory power management transition delays, see
* PCI Express Base Specification Revision 2.0 Section
* 6.6.1: Conventional Reset. Do not delay for
* devices powered on/off by corresponding bridge,
* because have already delayed for the bridge.
*/
if (dev->runtime_d3cold) {
if (dev->d3cold_delay)
msleep(dev->d3cold_delay);
/*
* When powering on a bridge from D3cold, the
* whole hierarchy may be powered on into
* D0uninitialized state, resume them to give
* them a chance to suspend again
*/
pci_wakeup_bus(dev->subordinate);
}
}
}
/**
* __pci_dev_set_current_state - Set current state of a PCI device
* @dev: Device to handle
* @data: pointer to state to be set
*/
static int __pci_dev_set_current_state(struct pci_dev *dev, void *data)
{
pci_power_t state = *(pci_power_t *)data;
dev->current_state = state;
return 0;
}
/**
* pci_bus_set_current_state - Walk given bus and set current state of devices
* @bus: Top bus of the subtree to walk.
* @state: state to be set
*/
void pci_bus_set_current_state(struct pci_bus *bus, pci_power_t state)
{
if (bus)
pci_walk_bus(bus, __pci_dev_set_current_state, &state);
}
/**
* __pci_complete_power_transition - Complete power transition of a PCI device
* @dev: PCI device to handle.
* @state: State to put the device into.
*
* This function should not be called directly by device drivers.
*/
int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state)
{
int ret;
if (state <= PCI_D0)
return -EINVAL;
ret = pci_platform_power_transition(dev, state);
/* Power off the bridge may power off the whole hierarchy */
if (!ret && state == PCI_D3cold)
pci_bus_set_current_state(dev->subordinate, PCI_D3cold);
return ret;
}
EXPORT_SYMBOL_GPL(__pci_complete_power_transition);
/**
* pci_set_power_state - Set the power state of a PCI device
* @dev: PCI device to handle.
* @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
*
* Transition a device to a new power state, using the platform firmware and/or
* the device's PCI PM registers.
*
* RETURN VALUE:
* -EINVAL if the requested state is invalid.
* -EIO if device does not support PCI PM or its PM capabilities register has a
* wrong version, or device doesn't support the requested state.
* 0 if the transition is to D1 or D2 but D1 and D2 are not supported.
* 0 if device already is in the requested state.
* 0 if the transition is to D3 but D3 is not supported.
* 0 if device's power state has been successfully changed.
*/
int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
{
int error;
/* bound the state we're entering */
if (state > PCI_D3cold)
state = PCI_D3cold;
else if (state < PCI_D0)
state = PCI_D0;
else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
/*
* If the device or the parent bridge do not support PCI PM,
* ignore the request if we're doing anything other than putting
* it into D0 (which would only happen on boot).
*/
return 0;
/* Check if we're already there */
if (dev->current_state == state)
return 0;
__pci_start_power_transition(dev, state);
/* This device is quirked not to be put into D3, so
don't put it in D3 */
if (state >= PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
return 0;
/*
* To put device in D3cold, we put device into D3hot in native
* way, then put device into D3cold with platform ops
*/
error = pci_raw_set_power_state(dev, state > PCI_D3hot ?
PCI_D3hot : state);
if (!__pci_complete_power_transition(dev, state))
error = 0;
return error;
}
EXPORT_SYMBOL(pci_set_power_state);
/**
* pci_choose_state - Choose the power state of a PCI device
* @dev: PCI device to be suspended
* @state: target sleep state for the whole system. This is the value
* that is passed to suspend() function.
*
* Returns PCI power state suitable for given device and given system
* message.
*/
pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
{
pci_power_t ret;
if (!dev->pm_cap)
return PCI_D0;
ret = platform_pci_choose_state(dev);
if (ret != PCI_POWER_ERROR)
return ret;
switch (state.event) {
case PM_EVENT_ON:
return PCI_D0;
case PM_EVENT_FREEZE:
case PM_EVENT_PRETHAW:
/* REVISIT both freeze and pre-thaw "should" use D0 */
case PM_EVENT_SUSPEND:
case PM_EVENT_HIBERNATE:
return PCI_D3hot;
default:
pci_info(dev, "unrecognized suspend event %d\n",
state.event);
BUG();
}
return PCI_D0;
}
EXPORT_SYMBOL(pci_choose_state);
#define PCI_EXP_SAVE_REGS 7
static struct pci_cap_saved_state *_pci_find_saved_cap(struct pci_dev *pci_dev,
u16 cap, bool extended)
{
struct pci_cap_saved_state *tmp;
hlist_for_each_entry(tmp, &pci_dev->saved_cap_space, next) {
if (tmp->cap.cap_extended == extended && tmp->cap.cap_nr == cap)
return tmp;
}
return NULL;
}
struct pci_cap_saved_state *pci_find_saved_cap(struct pci_dev *dev, char cap)
{
return _pci_find_saved_cap(dev, cap, false);
}
struct pci_cap_saved_state *pci_find_saved_ext_cap(struct pci_dev *dev, u16 cap)
{
return _pci_find_saved_cap(dev, cap, true);
}
static int pci_save_pcie_state(struct pci_dev *dev)
{
int i = 0;
struct pci_cap_saved_state *save_state;
u16 *cap;
if (!pci_is_pcie(dev))
return 0;
save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
if (!save_state) {
pci_err(dev, "buffer not found in %s\n", __func__);
return -ENOMEM;
}
cap = (u16 *)&save_state->cap.data[0];
pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &cap[i++]);
pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &cap[i++]);
pcie_capability_read_word(dev, PCI_EXP_SLTCTL, &cap[i++]);
pcie_capability_read_word(dev, PCI_EXP_RTCTL, &cap[i++]);
pcie_capability_read_word(dev, PCI_EXP_DEVCTL2, &cap[i++]);
pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &cap[i++]);
pcie_capability_read_word(dev, PCI_EXP_SLTCTL2, &cap[i++]);
return 0;
}
static void pci_restore_pcie_state(struct pci_dev *dev)
{
int i = 0;
struct pci_cap_saved_state *save_state;
u16 *cap;
save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
if (!save_state)
return;
cap = (u16 *)&save_state->cap.data[0];
pcie_capability_write_word(dev, PCI_EXP_DEVCTL, cap[i++]);
pcie_capability_write_word(dev, PCI_EXP_LNKCTL, cap[i++]);
pcie_capability_write_word(dev, PCI_EXP_SLTCTL, cap[i++]);
pcie_capability_write_word(dev, PCI_EXP_RTCTL, cap[i++]);
pcie_capability_write_word(dev, PCI_EXP_DEVCTL2, cap[i++]);
pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, cap[i++]);
pcie_capability_write_word(dev, PCI_EXP_SLTCTL2, cap[i++]);
}
static int pci_save_pcix_state(struct pci_dev *dev)
{
int pos;
struct pci_cap_saved_state *save_state;
pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!pos)
return 0;
save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
if (!save_state) {
pci_err(dev, "buffer not found in %s\n", __func__);
return -ENOMEM;
}
pci_read_config_word(dev, pos + PCI_X_CMD,
(u16 *)save_state->cap.data);
return 0;
}
static void pci_restore_pcix_state(struct pci_dev *dev)
{
int i = 0, pos;
struct pci_cap_saved_state *save_state;
u16 *cap;
save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!save_state || !pos)
return;
cap = (u16 *)&save_state->cap.data[0];
pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
}
/**
* pci_save_state - save the PCI configuration space of a device before suspending
* @dev: - PCI device that we're dealing with
*/
int pci_save_state(struct pci_dev *dev)
{
int i;
/* XXX: 100% dword access ok here? */
for (i = 0; i < 16; i++)
pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]);
dev->state_saved = true;
i = pci_save_pcie_state(dev);
if (i != 0)
return i;
i = pci_save_pcix_state(dev);
if (i != 0)
return i;
return pci_save_vc_state(dev);
}
EXPORT_SYMBOL(pci_save_state);
static void pci_restore_config_dword(struct pci_dev *pdev, int offset,
u32 saved_val, int retry)
{
u32 val;
pci_read_config_dword(pdev, offset, &val);
if (val == saved_val)
return;
for (;;) {
pci_dbg(pdev, "restoring config space at offset %#x (was %#x, writing %#x)\n",
offset, val, saved_val);
pci_write_config_dword(pdev, offset, saved_val);
if (retry-- <= 0)
return;
pci_read_config_dword(pdev, offset, &val);
if (val == saved_val)
return;
mdelay(1);
}
}
static void pci_restore_config_space_range(struct pci_dev *pdev,
int start, int end, int retry)
{
int index;
for (index = end; index >= start; index--)
pci_restore_config_dword(pdev, 4 * index,
pdev->saved_config_space[index],
retry);
}
static void pci_restore_config_space(struct pci_dev *pdev)
{
if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
pci_restore_config_space_range(pdev, 10, 15, 0);
/* Restore BARs before the command register. */
pci_restore_config_space_range(pdev, 4, 9, 10);
pci_restore_config_space_range(pdev, 0, 3, 0);
} else {
pci_restore_config_space_range(pdev, 0, 15, 0);
}
}
/**
* pci_restore_state - Restore the saved state of a PCI device
* @dev: - PCI device that we're dealing with
*/
void pci_restore_state(struct pci_dev *dev)
{
if (!dev->state_saved)
return;
/* PCI Express register must be restored first */
pci_restore_pcie_state(dev);
pci_restore_pasid_state(dev);
pci_restore_pri_state(dev);
pci_restore_ats_state(dev);
pci_restore_vc_state(dev);
pci_cleanup_aer_error_status_regs(dev);
pci_restore_config_space(dev);
pci_restore_pcix_state(dev);
pci_restore_msi_state(dev);
/* Restore ACS and IOV configuration state */
pci_enable_acs(dev);
pci_restore_iov_state(dev);
dev->state_saved = false;
}
EXPORT_SYMBOL(pci_restore_state);
struct pci_saved_state {
u32 config_space[16];
struct pci_cap_saved_data cap[0];
};
/**
* pci_store_saved_state - Allocate and return an opaque struct containing
* the device saved state.
* @dev: PCI device that we're dealing with
*
* Return NULL if no state or error.
*/
struct pci_saved_state *pci_store_saved_state(struct pci_dev *dev)
{
struct pci_saved_state *state;
struct pci_cap_saved_state *tmp;
struct pci_cap_saved_data *cap;
size_t size;
if (!dev->state_saved)
return NULL;
size = sizeof(*state) + sizeof(struct pci_cap_saved_data);
hlist_for_each_entry(tmp, &dev->saved_cap_space, next)
size += sizeof(struct pci_cap_saved_data) + tmp->cap.size;
state = kzalloc(size, GFP_KERNEL);
if (!state)
return NULL;
memcpy(state->config_space, dev->saved_config_space,
sizeof(state->config_space));
cap = state->cap;
hlist_for_each_entry(tmp, &dev->saved_cap_space, next) {
size_t len = sizeof(struct pci_cap_saved_data) + tmp->cap.size;
memcpy(cap, &tmp->cap, len);
cap = (struct pci_cap_saved_data *)((u8 *)cap + len);
}
/* Empty cap_save terminates list */
return state;
}
EXPORT_SYMBOL_GPL(pci_store_saved_state);
/**
* pci_load_saved_state - Reload the provided save state into struct pci_dev.
* @dev: PCI device that we're dealing with
* @state: Saved state returned from pci_store_saved_state()
*/
int pci_load_saved_state(struct pci_dev *dev,
struct pci_saved_state *state)
{
struct pci_cap_saved_data *cap;
dev->state_saved = false;
if (!state)
return 0;
memcpy(dev->saved_config_space, state->config_space,
sizeof(state->config_space));
cap = state->cap;
while (cap->size) {
struct pci_cap_saved_state *tmp;
tmp = _pci_find_saved_cap(dev, cap->cap_nr, cap->cap_extended);
if (!tmp || tmp->cap.size != cap->size)
return -EINVAL;
memcpy(tmp->cap.data, cap->data, tmp->cap.size);
cap = (struct pci_cap_saved_data *)((u8 *)cap +
sizeof(struct pci_cap_saved_data) + cap->size);
}
dev->state_saved = true;
return 0;
}
EXPORT_SYMBOL_GPL(pci_load_saved_state);
/**
* pci_load_and_free_saved_state - Reload the save state pointed to by state,
* and free the memory allocated for it.
* @dev: PCI device that we're dealing with
* @state: Pointer to saved state returned from pci_store_saved_state()
*/
int pci_load_and_free_saved_state(struct pci_dev *dev,
struct pci_saved_state **state)
{
int ret = pci_load_saved_state(dev, *state);
kfree(*state);
*state = NULL;
return ret;
}
EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state);
int __weak pcibios_enable_device(struct pci_dev *dev, int bars)
{
return pci_enable_resources(dev, bars);
}
static int do_pci_enable_device(struct pci_dev *dev, int bars)
{
int err;
struct pci_dev *bridge;
u16 cmd;
u8 pin;
err = pci_set_power_state(dev, PCI_D0);
if (err < 0 && err != -EIO)
return err;
bridge = pci_upstream_bridge(dev);
if (bridge)
pcie_aspm_powersave_config_link(bridge);
err = pcibios_enable_device(dev, bars);
if (err < 0)
return err;
pci_fixup_device(pci_fixup_enable, dev);
if (dev->msi_enabled || dev->msix_enabled)
return 0;
pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
if (pin) {
pci_read_config_word(dev, PCI_COMMAND, &cmd);
if (cmd & PCI_COMMAND_INTX_DISABLE)
pci_write_config_word(dev, PCI_COMMAND,
cmd & ~PCI_COMMAND_INTX_DISABLE);
}
return 0;
}
/**
* pci_reenable_device - Resume abandoned device
* @dev: PCI device to be resumed
*
* Note this function is a backend of pci_default_resume and is not supposed
* to be called by normal code, write proper resume handler and use it instead.
*/
int pci_reenable_device(struct pci_dev *dev)
{
if (pci_is_enabled(dev))
return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1);
return 0;
}
EXPORT_SYMBOL(pci_reenable_device);
static void pci_enable_bridge(struct pci_dev *dev)
{
struct pci_dev *bridge;
int retval;
bridge = pci_upstream_bridge(dev);
if (bridge)
pci_enable_bridge(bridge);
if (pci_is_enabled(dev)) {
if (!dev->is_busmaster)
pci_set_master(dev);
return;
}
retval = pci_enable_device(dev);
if (retval)
pci_err(dev, "Error enabling bridge (%d), continuing\n",
retval);
pci_set_master(dev);
}
static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
{
struct pci_dev *bridge;
int err;
int i, bars = 0;
/*
* Power state could be unknown at this point, either due to a fresh
* boot or a device removal call. So get the current power state
* so that things like MSI message writing will behave as expected
* (e.g. if the device really is in D0 at enable time).
*/
if (dev->pm_cap) {
u16 pmcsr;
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
}
if (atomic_inc_return(&dev->enable_cnt) > 1)
return 0; /* already enabled */
bridge = pci_upstream_bridge(dev);
if (bridge)
pci_enable_bridge(bridge);
/* only skip sriov related */
for (i = 0; i <= PCI_ROM_RESOURCE; i++)
if (dev->resource[i].flags & flags)
bars |= (1 << i);
for (i = PCI_BRIDGE_RESOURCES; i < DEVICE_COUNT_RESOURCE; i++)
if (dev->resource[i].flags & flags)
bars |= (1 << i);
err = do_pci_enable_device(dev, bars);
if (err < 0)
atomic_dec(&dev->enable_cnt);
return err;
}
/**
* pci_enable_device_io - Initialize a device for use with IO space
* @dev: PCI device to be initialized
*
* Initialize device before it's used by a driver. Ask low-level code
* to enable I/O resources. Wake up the device if it was suspended.
* Beware, this function can fail.
*/
int pci_enable_device_io(struct pci_dev *dev)
{
return pci_enable_device_flags(dev, IORESOURCE_IO);
}
EXPORT_SYMBOL(pci_enable_device_io);
/**
* pci_enable_device_mem - Initialize a device for use with Memory space
* @dev: PCI device to be initialized
*
* Initialize device before it's used by a driver. Ask low-level code
* to enable Memory resources. Wake up the device if it was suspended.
* Beware, this function can fail.
*/
int pci_enable_device_mem(struct pci_dev *dev)
{
return pci_enable_device_flags(dev, IORESOURCE_MEM);
}
EXPORT_SYMBOL(pci_enable_device_mem);
/**
* pci_enable_device - Initialize device before it's used by a driver.
* @dev: PCI device to be initialized
*
* Initialize device before it's used by a driver. Ask low-level code
* to enable I/O and memory. Wake up the device if it was suspended.
* Beware, this function can fail.
*
* Note we don't actually enable the device many times if we call
* this function repeatedly (we just increment the count).
*/
int pci_enable_device(struct pci_dev *dev)
{
return pci_enable_device_flags(dev, IORESOURCE_MEM | IORESOURCE_IO);
}
EXPORT_SYMBOL(pci_enable_device);
/*
* Managed PCI resources. This manages device on/off, intx/msi/msix
* on/off and BAR regions. pci_dev itself records msi/msix status, so
* there's no need to track it separately. pci_devres is initialized
* when a device is enabled using managed PCI device enable interface.
*/
struct pci_devres {
unsigned int enabled:1;
unsigned int pinned:1;
unsigned int orig_intx:1;
unsigned int restore_intx:1;
unsigned int mwi:1;
u32 region_mask;
};
static void pcim_release(struct device *gendev, void *res)
{
struct pci_dev *dev = to_pci_dev(gendev);
struct pci_devres *this = res;
int i;
if (dev->msi_enabled)
pci_disable_msi(dev);
if (dev->msix_enabled)
pci_disable_msix(dev);
for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
if (this->region_mask & (1 << i))
pci_release_region(dev, i);
if (this->mwi)
pci_clear_mwi(dev);
if (this->restore_intx)
pci_intx(dev, this->orig_intx);
if (this->enabled && !this->pinned)
pci_disable_device(dev);
}
static struct pci_devres *get_pci_dr(struct pci_dev *pdev)
{
struct pci_devres *dr, *new_dr;
dr = devres_find(&pdev->dev, pcim_release, NULL, NULL);
if (dr)
return dr;
new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL);
if (!new_dr)
return NULL;
return devres_get(&pdev->dev, new_dr, NULL, NULL);
}
static struct pci_devres *find_pci_dr(struct pci_dev *pdev)
{
if (pci_is_managed(pdev))
return devres_find(&pdev->dev, pcim_release, NULL, NULL);
return NULL;
}
/**
* pcim_enable_device - Managed pci_enable_device()
* @pdev: PCI device to be initialized
*
* Managed pci_enable_device().
*/
int pcim_enable_device(struct pci_dev *pdev)
{
struct pci_devres *dr;
int rc;
dr = get_pci_dr(pdev);
if (unlikely(!dr))
return -ENOMEM;
if (dr->enabled)
return 0;
rc = pci_enable_device(pdev);
if (!rc) {
pdev->is_managed = 1;
dr->enabled = 1;
}
return rc;
}
EXPORT_SYMBOL(pcim_enable_device);
/**
* pcim_pin_device - Pin managed PCI device
* @pdev: PCI device to pin
*
* Pin managed PCI device @pdev. Pinned device won't be disabled on
* driver detach. @pdev must have been enabled with
* pcim_enable_device().
*/
void pcim_pin_device(struct pci_dev *pdev)
{
struct pci_devres *dr;
dr = find_pci_dr(pdev);
WARN_ON(!dr || !dr->enabled);
if (dr)
dr->pinned = 1;
}
EXPORT_SYMBOL(pcim_pin_device);
/*
* pcibios_add_device - provide arch specific hooks when adding device dev
* @dev: the PCI device being added
*
* Permits the platform to provide architecture specific functionality when
* devices are added. This is the default implementation. Architecture
* implementations can override this.
*/
int __weak pcibios_add_device(struct pci_dev *dev)
{
return 0;
}
/**
* pcibios_release_device - provide arch specific hooks when releasing device dev
* @dev: the PCI device being released
*
* Permits the platform to provide architecture specific functionality when
* devices are released. This is the default implementation. Architecture
* implementations can override this.
*/
void __weak pcibios_release_device(struct pci_dev *dev) {}
/**
* pcibios_disable_device - disable arch specific PCI resources for device dev
* @dev: the PCI device to disable
*
* Disables architecture specific PCI resources for the device. This
* is the default implementation. Architecture implementations can
* override this.
*/
void __weak pcibios_disable_device(struct pci_dev *dev) {}
/**
* pcibios_penalize_isa_irq - penalize an ISA IRQ
* @irq: ISA IRQ to penalize
* @active: IRQ active or not
*
* Permits the platform to provide architecture-specific functionality when
* penalizing ISA IRQs. This is the default implementation. Architecture
* implementations can override this.
*/
void __weak pcibios_penalize_isa_irq(int irq, int active) {}
static void do_pci_disable_device(struct pci_dev *dev)
{
u16 pci_command;
pci_read_config_word(dev, PCI_COMMAND, &pci_command);
if (pci_command & PCI_COMMAND_MASTER) {
pci_command &= ~PCI_COMMAND_MASTER;
pci_write_config_word(dev, PCI_COMMAND, pci_command);
}
pcibios_disable_device(dev);
}
/**
* pci_disable_enabled_device - Disable device without updating enable_cnt
* @dev: PCI device to disable
*
* NOTE: This function is a backend of PCI power management routines and is
* not supposed to be called drivers.
*/
void pci_disable_enabled_device(struct pci_dev *dev)
{
if (pci_is_enabled(dev))
do_pci_disable_device(dev);
}
/**
* pci_disable_device - Disable PCI device after use
* @dev: PCI device to be disabled
*
* Signal to the system that the PCI device is not in use by the system
* anymore. This only involves disabling PCI bus-mastering, if active.
*
* Note we don't actually disable the device until all callers of
* pci_enable_device() have called pci_disable_device().
*/
void pci_disable_device(struct pci_dev *dev)
{
struct pci_devres *dr;
dr = find_pci_dr(dev);
if (dr)
dr->enabled = 0;
dev_WARN_ONCE(&dev->dev, atomic_read(&dev->enable_cnt) <= 0,
"disabling already-disabled device");
if (atomic_dec_return(&dev->enable_cnt) != 0)
return;
do_pci_disable_device(dev);
dev->is_busmaster = 0;
}
EXPORT_SYMBOL(pci_disable_device);
/**
* pcibios_set_pcie_reset_state - set reset state for device dev
* @dev: the PCIe device reset
* @state: Reset state to enter into
*
*
* Sets the PCIe reset state for the device. This is the default
* implementation. Architecture implementations can override this.
*/
int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev,
enum pcie_reset_state state)
{
return -EINVAL;
}
/**
* pci_set_pcie_reset_state - set reset state for device dev
* @dev: the PCIe device reset
* @state: Reset state to enter into
*
*
* Sets the PCI reset state for the device.
*/
int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
{
return pcibios_set_pcie_reset_state(dev, state);
}
EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);
/**
* pci_check_pme_status - Check if given device has generated PME.
* @dev: Device to check.
*
* Check the PME status of the device and if set, clear it and clear PME enable
* (if set). Return 'true' if PME status and PME enable were both set or
* 'false' otherwise.
*/
bool pci_check_pme_status(struct pci_dev *dev)
{
int pmcsr_pos;
u16 pmcsr;
bool ret = false;
if (!dev->pm_cap)
return false;
pmcsr_pos = dev->pm_cap + PCI_PM_CTRL;
pci_read_config_word(dev, pmcsr_pos, &pmcsr);
if (!(pmcsr & PCI_PM_CTRL_PME_STATUS))
return false;
/* Clear PME status. */
pmcsr |= PCI_PM_CTRL_PME_STATUS;
if (pmcsr & PCI_PM_CTRL_PME_ENABLE) {
/* Disable PME to avoid interrupt flood. */
pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
ret = true;
}
pci_write_config_word(dev, pmcsr_pos, pmcsr);
return ret;
}
/**
* pci_pme_wakeup - Wake up a PCI device if its PME Status bit is set.
* @dev: Device to handle.
* @pme_poll_reset: Whether or not to reset the device's pme_poll flag.
*
* Check if @dev has generated PME and queue a resume request for it in that
* case.
*/
static int pci_pme_wakeup(struct pci_dev *dev, void *pme_poll_reset)
{
if (pme_poll_reset && dev->pme_poll)
dev->pme_poll = false;
if (pci_check_pme_status(dev)) {
pci_wakeup_event(dev);
pm_request_resume(&dev->dev);
}
return 0;
}
/**
* pci_pme_wakeup_bus - Walk given bus and wake up devices on it, if necessary.
* @bus: Top bus of the subtree to walk.
*/
void pci_pme_wakeup_bus(struct pci_bus *bus)
{
if (bus)
pci_walk_bus(bus, pci_pme_wakeup, (void *)true);
}
/**
* pci_pme_capable - check the capability of PCI device to generate PME#
* @dev: PCI device to handle.
* @state: PCI state from which device will issue PME#.
*/
bool pci_pme_capable(struct pci_dev *dev, pci_power_t state)
{
if (!dev->pm_cap)
return false;
return !!(dev->pme_support & (1 << state));
}
EXPORT_SYMBOL(pci_pme_capable);
static void pci_pme_list_scan(struct work_struct *work)
{
struct pci_pme_device *pme_dev, *n;
mutex_lock(&pci_pme_list_mutex);
list_for_each_entry_safe(pme_dev, n, &pci_pme_list, list) {
if (pme_dev->dev->pme_poll) {
struct pci_dev *bridge;
bridge = pme_dev->dev->bus->self;
/*
* If bridge is in low power state, the
* configuration space of subordinate devices
* may be not accessible
*/
if (bridge && bridge->current_state != PCI_D0)
continue;
pci_pme_wakeup(pme_dev->dev, NULL);
} else {
list_del(&pme_dev->list);
kfree(pme_dev);
}
}
if (!list_empty(&pci_pme_list))
queue_delayed_work(system_freezable_wq, &pci_pme_work,
msecs_to_jiffies(PME_TIMEOUT));
mutex_unlock(&pci_pme_list_mutex);
}
static void __pci_pme_active(struct pci_dev *dev, bool enable)
{
u16 pmcsr;
if (!dev->pme_support)
return;
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
/* Clear PME_Status by writing 1 to it and enable PME# */
pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
if (!enable)
pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
}
/**
* pci_pme_restore - Restore PME configuration after config space restore.
* @dev: PCI device to update.
*/
void pci_pme_restore(struct pci_dev *dev)
{
u16 pmcsr;
if (!dev->pme_support)
return;
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
if (dev->wakeup_prepared) {
pmcsr |= PCI_PM_CTRL_PME_ENABLE;
pmcsr &= ~PCI_PM_CTRL_PME_STATUS;
} else {
pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
pmcsr |= PCI_PM_CTRL_PME_STATUS;
}
pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
}
/**
* pci_pme_active - enable or disable PCI device's PME# function
* @dev: PCI device to handle.
* @enable: 'true' to enable PME# generation; 'false' to disable it.
*
* The caller must verify that the device is capable of generating PME# before
* calling this function with @enable equal to 'true'.
*/
void pci_pme_active(struct pci_dev *dev, bool enable)
{
__pci_pme_active(dev, enable);
/*
* PCI (as opposed to PCIe) PME requires that the device have
* its PME# line hooked up correctly. Not all hardware vendors
* do this, so the PME never gets delivered and the device
* remains asleep. The easiest way around this is to
* periodically walk the list of suspended devices and check
* whether any have their PME flag set. The assumption is that
* we'll wake up often enough anyway that this won't be a huge
* hit, and the power savings from the devices will still be a
* win.
*
* Although PCIe uses in-band PME message instead of PME# line
* to report PME, PME does not work for some PCIe devices in
* reality. For example, there are devices that set their PME
* status bits, but don't really bother to send a PME message;
* there are PCI Express Root Ports that don't bother to
* trigger interrupts when they receive PME messages from the
* devices below. So PME poll is used for PCIe devices too.
*/
if (dev->pme_poll) {
struct pci_pme_device *pme_dev;
if (enable) {
pme_dev = kmalloc(sizeof(struct pci_pme_device),
GFP_KERNEL);
if (!pme_dev) {
pci_warn(dev, "can't enable PME#\n");
return;
}
pme_dev->dev = dev;
mutex_lock(&pci_pme_list_mutex);
list_add(&pme_dev->list, &pci_pme_list);
if (list_is_singular(&pci_pme_list))
queue_delayed_work(system_freezable_wq,
&pci_pme_work,
msecs_to_jiffies(PME_TIMEOUT));
mutex_unlock(&pci_pme_list_mutex);
} else {
mutex_lock(&pci_pme_list_mutex);
list_for_each_entry(pme_dev, &pci_pme_list, list) {
if (pme_dev->dev == dev) {
list_del(&pme_dev->list);
kfree(pme_dev);
break;
}
}
mutex_unlock(&pci_pme_list_mutex);
}
}
pci_dbg(dev, "PME# %s\n", enable ? "enabled" : "disabled");
}
EXPORT_SYMBOL(pci_pme_active);
/**
* pci_enable_wake - enable PCI device as wakeup event source
* @dev: PCI device affected
* @state: PCI state from which device will issue wakeup events
* @enable: True to enable event generation; false to disable
*
* This enables the device as a wakeup event source, or disables it.
* When such events involves platform-specific hooks, those hooks are
* called automatically by this routine.
*
* Devices with legacy power management (no standard PCI PM capabilities)
* always require such platform hooks.
*
* RETURN VALUE:
* 0 is returned on success
* -EINVAL is returned if device is not supposed to wake up the system
* Error code depending on the platform is returned if both the platform and
* the native mechanism fail to enable the generation of wake-up events
*/
int pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable)
{
int ret = 0;
/*
* Bridges can only signal wakeup on behalf of subordinate devices,
* but that is set up elsewhere, so skip them.
*/
if (pci_has_subordinate(dev))
return 0;
/* Don't do the same thing twice in a row for one device. */
if (!!enable == !!dev->wakeup_prepared)
return 0;
/*
* According to "PCI System Architecture" 4th ed. by Tom Shanley & Don
* Anderson we should be doing PME# wake enable followed by ACPI wake
* enable. To disable wake-up we call the platform first, for symmetry.
*/
if (enable) {
int error;
if (pci_pme_capable(dev, state))
pci_pme_active(dev, true);
else
ret = 1;
error = platform_pci_set_wakeup(dev, true);
if (ret)
ret = error;
if (!ret)
dev->wakeup_prepared = true;
} else {
platform_pci_set_wakeup(dev, false);
pci_pme_active(dev, false);
dev->wakeup_prepared = false;
}
return ret;
}
EXPORT_SYMBOL(pci_enable_wake);
/**
* pci_wake_from_d3 - enable/disable device to wake up from D3_hot or D3_cold
* @dev: PCI device to prepare
* @enable: True to enable wake-up event generation; false to disable
*
* Many drivers want the device to wake up the system from D3_hot or D3_cold
* and this function allows them to set that up cleanly - pci_enable_wake()
* should not be called twice in a row to enable wake-up due to PCI PM vs ACPI
* ordering constraints.
*
* This function only returns error code if the device is not capable of
* generating PME# from both D3_hot and D3_cold, and the platform is unable to
* enable wake-up power for it.
*/
int pci_wake_from_d3(struct pci_dev *dev, bool enable)
{
return pci_pme_capable(dev, PCI_D3cold) ?
pci_enable_wake(dev, PCI_D3cold, enable) :
pci_enable_wake(dev, PCI_D3hot, enable);
}
EXPORT_SYMBOL(pci_wake_from_d3);
/**
* pci_target_state - find an appropriate low power state for a given PCI dev
* @dev: PCI device
* @wakeup: Whether or not wakeup functionality will be enabled for the device.
*
* Use underlying platform code to find a supported low power state for @dev.
* If the platform can't manage @dev, return the deepest state from which it
* can generate wake events, based on any available PME info.
*/
static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup)
{
pci_power_t target_state = PCI_D3hot;
if (platform_pci_power_manageable(dev)) {
/*
* Call the platform to choose the target state of the device
* and enable wake-up from this state if supported.
*/
pci_power_t state = platform_pci_choose_state(dev);
switch (state) {
case PCI_POWER_ERROR:
case PCI_UNKNOWN:
break;
case PCI_D1:
case PCI_D2:
if (pci_no_d1d2(dev))
break;
default:
target_state = state;
}
return target_state;
}
if (!dev->pm_cap)
target_state = PCI_D0;
/*
* If the device is in D3cold even though it's not power-manageable by
* the platform, it may have been powered down by non-standard means.
* Best to let it slumber.
*/
if (dev->current_state == PCI_D3cold)
target_state = PCI_D3cold;
if (wakeup) {
/*
* Find the deepest state from which the device can generate
* wake-up events, make it the target state and enable device
* to generate PME#.
*/
if (dev->pme_support) {
while (target_state
&& !(dev->pme_support & (1 << target_state)))
target_state--;
}
}
return target_state;
}
/**
* pci_prepare_to_sleep - prepare PCI device for system-wide transition into a sleep state
* @dev: Device to handle.
*
* Choose the power state appropriate for the device depending on whether
* it can wake up the system and/or is power manageable by the platform
* (PCI_D3hot is the default) and put the device into that state.
*/
int pci_prepare_to_sleep(struct pci_dev *dev)
{
bool wakeup = device_may_wakeup(&dev->dev);
pci_power_t target_state = pci_target_state(dev, wakeup);
int error;
if (target_state == PCI_POWER_ERROR)
return -EIO;
pci_enable_wake(dev, target_state, wakeup);
error = pci_set_power_state(dev, target_state);
if (error)
pci_enable_wake(dev, target_state, false);
return error;
}
EXPORT_SYMBOL(pci_prepare_to_sleep);
/**
* pci_back_from_sleep - turn PCI device on during system-wide transition into working state
* @dev: Device to handle.
*
* Disable device's system wake-up capability and put it into D0.
*/
int pci_back_from_sleep(struct pci_dev *dev)
{
pci_enable_wake(dev, PCI_D0, false);
return pci_set_power_state(dev, PCI_D0);
}
EXPORT_SYMBOL(pci_back_from_sleep);
/**
* pci_finish_runtime_suspend - Carry out PCI-specific part of runtime suspend.
* @dev: PCI device being suspended.
*
* Prepare @dev to generate wake-up events at run time and put it into a low
* power state.
*/
int pci_finish_runtime_suspend(struct pci_dev *dev)
{
pci_power_t target_state;
int error;
target_state = pci_target_state(dev, device_can_wakeup(&dev->dev));
if (target_state == PCI_POWER_ERROR)
return -EIO;
dev->runtime_d3cold = target_state == PCI_D3cold;
pci_enable_wake(dev, target_state, pci_dev_run_wake(dev));
error = pci_set_power_state(dev, target_state);
if (error) {
pci_enable_wake(dev, target_state, false);
dev->runtime_d3cold = false;
}
return error;
}
/**
* pci_dev_run_wake - Check if device can generate run-time wake-up events.
* @dev: Device to check.
*
* Return true if the device itself is capable of generating wake-up events
* (through the platform or using the native PCIe PME) or if the device supports
* PME and one of its upstream bridges can generate wake-up events.
*/
bool pci_dev_run_wake(struct pci_dev *dev)
{
struct pci_bus *bus = dev->bus;
if (device_can_wakeup(&dev->dev))
return true;
if (!dev->pme_support)
return false;
/* PME-capable in principle, but not from the target power state */
if (!pci_pme_capable(dev, pci_target_state(dev, false)))
return false;
while (bus->parent) {
struct pci_dev *bridge = bus->self;
if (device_can_wakeup(&bridge->dev))
return true;
bus = bus->parent;
}
/* We have reached the root bus. */
if (bus->bridge)
return device_can_wakeup(bus->bridge);
return false;
}
EXPORT_SYMBOL_GPL(pci_dev_run_wake);
/**
* pci_dev_keep_suspended - Check if the device can stay in the suspended state.
* @pci_dev: Device to check.
*
* Return 'true' if the device is runtime-suspended, it doesn't have to be
* reconfigured due to wakeup settings difference between system and runtime
* suspend and the current power state of it is suitable for the upcoming
* (system) transition.
*
* If the device is not configured for system wakeup, disable PME for it before
* returning 'true' to prevent it from waking up the system unnecessarily.
*/
bool pci_dev_keep_suspended(struct pci_dev *pci_dev)
{
struct device *dev = &pci_dev->dev;
bool wakeup = device_may_wakeup(dev);
if (!pm_runtime_suspended(dev)
|| pci_target_state(pci_dev, wakeup) != pci_dev->current_state
|| platform_pci_need_resume(pci_dev))
return false;
/*
* At this point the device is good to go unless it's been configured
* to generate PME at the runtime suspend time, but it is not supposed
* to wake up the system. In that case, simply disable PME for it
* (it will have to be re-enabled on exit from system resume).
*
* If the device's power state is D3cold and the platform check above
* hasn't triggered, the device's configuration is suitable and we don't
* need to manipulate it at all.
*/
spin_lock_irq(&dev->power.lock);
if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold &&
!wakeup)
__pci_pme_active(pci_dev, false);
spin_unlock_irq(&dev->power.lock);
return true;
}
/**
* pci_dev_complete_resume - Finalize resume from system sleep for a device.
* @pci_dev: Device to handle.
*
* If the device is runtime suspended and wakeup-capable, enable PME for it as
* it might have been disabled during the prepare phase of system suspend if
* the device was not configured for system wakeup.
*/
void pci_dev_complete_resume(struct pci_dev *pci_dev)
{
struct device *dev = &pci_dev->dev;
if (!pci_dev_run_wake(pci_dev))
return;
spin_lock_irq(&dev->power.lock);
if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold)
__pci_pme_active(pci_dev, true);
spin_unlock_irq(&dev->power.lock);
}
void pci_config_pm_runtime_get(struct pci_dev *pdev)
{
struct device *dev = &pdev->dev;
struct device *parent = dev->parent;
if (parent)
pm_runtime_get_sync(parent);
pm_runtime_get_noresume(dev);
/*
* pdev->current_state is set to PCI_D3cold during suspending,
* so wait until suspending completes
*/
pm_runtime_barrier(dev);
/*
* Only need to resume devices in D3cold, because config
* registers are still accessible for devices suspended but
* not in D3cold.
*/
if (pdev->current_state == PCI_D3cold)
pm_runtime_resume(dev);
}
void pci_config_pm_runtime_put(struct pci_dev *pdev)
{
struct device *dev = &pdev->dev;
struct device *parent = dev->parent;
pm_runtime_put(dev);
if (parent)
pm_runtime_put_sync(parent);
}
/**
* pci_bridge_d3_possible - Is it possible to put the bridge into D3
* @bridge: Bridge to check
*
* This function checks if it is possible to move the bridge to D3.
* Currently we only allow D3 for recent enough PCIe ports.
*/
bool pci_bridge_d3_possible(struct pci_dev *bridge)
{
unsigned int year;
if (!pci_is_pcie(bridge))
return false;
switch (pci_pcie_type(bridge)) {
case PCI_EXP_TYPE_ROOT_PORT:
case PCI_EXP_TYPE_UPSTREAM:
case PCI_EXP_TYPE_DOWNSTREAM:
if (pci_bridge_d3_disable)
return false;
/*
* Hotplug interrupts cannot be delivered if the link is down,
* so parents of a hotplug port must stay awake. In addition,
* hotplug ports handled by firmware in System Management Mode
* may not be put into D3 by the OS (Thunderbolt on non-Macs).
* For simplicity, disallow in general for now.
*/
if (bridge->is_hotplug_bridge)
return false;
if (pci_bridge_d3_force)
return true;
/*
* It should be safe to put PCIe ports from 2015 or newer
* to D3.
*/
if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) &&
year >= 2015) {
return true;
}
break;
}
return false;
}
static int pci_dev_check_d3cold(struct pci_dev *dev, void *data)
{
bool *d3cold_ok = data;
if (/* The device needs to be allowed to go D3cold ... */
dev->no_d3cold || !dev->d3cold_allowed ||
/* ... and if it is wakeup capable to do so from D3cold. */
(device_may_wakeup(&dev->dev) &&
!pci_pme_capable(dev, PCI_D3cold)) ||
/* If it is a bridge it must be allowed to go to D3. */
!pci_power_manageable(dev))
*d3cold_ok = false;
return !*d3cold_ok;
}
/*
* pci_bridge_d3_update - Update bridge D3 capabilities
* @dev: PCI device which is changed
*
* Update upstream bridge PM capabilities accordingly depending on if the
* device PM configuration was changed or the device is being removed. The
* change is also propagated upstream.
*/
void pci_bridge_d3_update(struct pci_dev *dev)
{
bool remove = !device_is_registered(&dev->dev);
struct pci_dev *bridge;
bool d3cold_ok = true;
bridge = pci_upstream_bridge(dev);
if (!bridge || !pci_bridge_d3_possible(bridge))
return;
/*
* If D3 is currently allowed for the bridge, removing one of its
* children won't change that.
*/
if (remove && bridge->bridge_d3)
return;
/*
* If D3 is currently allowed for the bridge and a child is added or
* changed, disallowance of D3 can only be caused by that child, so
* we only need to check that single device, not any of its siblings.
*
* If D3 is currently not allowed for the bridge, checking the device
* first may allow us to skip checking its siblings.
*/
if (!remove)
pci_dev_check_d3cold(dev, &d3cold_ok);
/*
* If D3 is currently not allowed for the bridge, this may be caused
* either by the device being changed/removed or any of its siblings,
* so we need to go through all children to find out if one of them
* continues to block D3.
*/
if (d3cold_ok && !bridge->bridge_d3)
pci_walk_bus(bridge->subordinate, pci_dev_check_d3cold,
&d3cold_ok);
if (bridge->bridge_d3 != d3cold_ok) {
bridge->bridge_d3 = d3cold_ok;
/* Propagate change to upstream bridges */
pci_bridge_d3_update(bridge);
}
}
/**
* pci_d3cold_enable - Enable D3cold for device
* @dev: PCI device to handle
*
* This function can be used in drivers to enable D3cold from the device
* they handle. It also updates upstream PCI bridge PM capabilities
* accordingly.
*/
void pci_d3cold_enable(struct pci_dev *dev)
{
if (dev->no_d3cold) {
dev->no_d3cold = false;
pci_bridge_d3_update(dev);
}
}
EXPORT_SYMBOL_GPL(pci_d3cold_enable);
/**
* pci_d3cold_disable - Disable D3cold for device
* @dev: PCI device to handle
*
* This function can be used in drivers to disable D3cold from the device
* they handle. It also updates upstream PCI bridge PM capabilities
* accordingly.
*/
void pci_d3cold_disable(struct pci_dev *dev)
{
if (!dev->no_d3cold) {
dev->no_d3cold = true;
pci_bridge_d3_update(dev);
}
}
EXPORT_SYMBOL_GPL(pci_d3cold_disable);
/**
* pci_pm_init - Initialize PM functions of given PCI device
* @dev: PCI device to handle.
*/
void pci_pm_init(struct pci_dev *dev)
{
int pm;
u16 pmc;
pm_runtime_forbid(&dev->dev);
pm_runtime_set_active(&dev->dev);
pm_runtime_enable(&dev->dev);
device_enable_async_suspend(&dev->dev);
dev->wakeup_prepared = false;
dev->pm_cap = 0;
dev->pme_support = 0;
/* find PCI PM capability in list */
pm = pci_find_capability(dev, PCI_CAP_ID_PM);
if (!pm)
return;
/* Check device's ability to generate PME# */
pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
pci_err(dev, "unsupported PM cap regs version (%u)\n",
pmc & PCI_PM_CAP_VER_MASK);
return;
}
dev->pm_cap = pm;
dev->d3_delay = PCI_PM_D3_WAIT;
dev->d3cold_delay = PCI_PM_D3COLD_WAIT;
dev->bridge_d3 = pci_bridge_d3_possible(dev);
dev->d3cold_allowed = true;
dev->d1_support = false;
dev->d2_support = false;
if (!pci_no_d1d2(dev)) {
if (pmc & PCI_PM_CAP_D1)
dev->d1_support = true;
if (pmc & PCI_PM_CAP_D2)
dev->d2_support = true;
if (dev->d1_support || dev->d2_support)
pci_printk(KERN_DEBUG, dev, "supports%s%s\n",
dev->d1_support ? " D1" : "",
dev->d2_support ? " D2" : "");
}
pmc &= PCI_PM_CAP_PME_MASK;
if (pmc) {
pci_printk(KERN_DEBUG, dev, "PME# supported from%s%s%s%s%s\n",
(pmc & PCI_PM_CAP_PME_D0) ? " D0" : "",
(pmc & PCI_PM_CAP_PME_D1) ? " D1" : "",
(pmc & PCI_PM_CAP_PME_D2) ? " D2" : "",
(pmc & PCI_PM_CAP_PME_D3) ? " D3hot" : "",
(pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : "");
dev->pme_support = pmc >> PCI_PM_CAP_PME_SHIFT;
dev->pme_poll = true;
/*
* Make device's PM flags reflect the wake-up capability, but
* let the user space enable it to wake up the system as needed.
*/
device_set_wakeup_capable(&dev->dev, true);
/* Disable the PME# generation functionality */
pci_pme_active(dev, false);
}
}
static unsigned long pci_ea_flags(struct pci_dev *dev, u8 prop)
{
unsigned long flags = IORESOURCE_PCI_FIXED | IORESOURCE_PCI_EA_BEI;
switch (prop) {
case PCI_EA_P_MEM:
case PCI_EA_P_VF_MEM:
flags |= IORESOURCE_MEM;
break;
case PCI_EA_P_MEM_PREFETCH:
case PCI_EA_P_VF_MEM_PREFETCH:
flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
break;
case PCI_EA_P_IO:
flags |= IORESOURCE_IO;
break;
default:
return 0;
}
return flags;
}
static struct resource *pci_ea_get_resource(struct pci_dev *dev, u8 bei,
u8 prop)
{
if (bei <= PCI_EA_BEI_BAR5 && prop <= PCI_EA_P_IO)
return &dev->resource[bei];
#ifdef CONFIG_PCI_IOV
else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5 &&
(prop == PCI_EA_P_VF_MEM || prop == PCI_EA_P_VF_MEM_PREFETCH))
return &dev->resource[PCI_IOV_RESOURCES +
bei - PCI_EA_BEI_VF_BAR0];
#endif
else if (bei == PCI_EA_BEI_ROM)
return &dev->resource[PCI_ROM_RESOURCE];
else
return NULL;
}
/* Read an Enhanced Allocation (EA) entry */
static int pci_ea_read(struct pci_dev *dev, int offset)
{
struct resource *res;
int ent_size, ent_offset = offset;
resource_size_t start, end;
unsigned long flags;
u32 dw0, bei, base, max_offset;
u8 prop;
bool support_64 = (sizeof(resource_size_t) >= 8);
pci_read_config_dword(dev, ent_offset, &dw0);
ent_offset += 4;
/* Entry size field indicates DWORDs after 1st */
ent_size = ((dw0 & PCI_EA_ES) + 1) << 2;
if (!(dw0 & PCI_EA_ENABLE)) /* Entry not enabled */
goto out;
bei = (dw0 & PCI_EA_BEI) >> 4;
prop = (dw0 & PCI_EA_PP) >> 8;
/*
* If the Property is in the reserved range, try the Secondary
* Property instead.
*/
if (prop > PCI_EA_P_BRIDGE_IO && prop < PCI_EA_P_MEM_RESERVED)
prop = (dw0 & PCI_EA_SP) >> 16;
if (prop > PCI_EA_P_BRIDGE_IO)
goto out;
res = pci_ea_get_resource(dev, bei, prop);
if (!res) {
pci_err(dev, "Unsupported EA entry BEI: %u\n", bei);
goto out;
}
flags = pci_ea_flags(dev, prop);
if (!flags) {
pci_err(dev, "Unsupported EA properties: %#x\n", prop);
goto out;
}
/* Read Base */
pci_read_config_dword(dev, ent_offset, &base);
start = (base & PCI_EA_FIELD_MASK);
ent_offset += 4;
/* Read MaxOffset */
pci_read_config_dword(dev, ent_offset, &max_offset);
ent_offset += 4;
/* Read Base MSBs (if 64-bit entry) */
if (base & PCI_EA_IS_64) {
u32 base_upper;
pci_read_config_dword(dev, ent_offset, &base_upper);
ent_offset += 4;
flags |= IORESOURCE_MEM_64;
/* entry starts above 32-bit boundary, can't use */
if (!support_64 && base_upper)
goto out;
if (support_64)
start |= ((u64)base_upper << 32);
}
end = start + (max_offset | 0x03);
/* Read MaxOffset MSBs (if 64-bit entry) */
if (max_offset & PCI_EA_IS_64) {
u32 max_offset_upper;
pci_read_config_dword(dev, ent_offset, &max_offset_upper);
ent_offset += 4;
flags |= IORESOURCE_MEM_64;
/* entry too big, can't use */
if (!support_64 && max_offset_upper)
goto out;
if (support_64)
end += ((u64)max_offset_upper << 32);
}
if (end < start) {
pci_err(dev, "EA Entry crosses address boundary\n");
goto out;
}
if (ent_size != ent_offset - offset) {
pci_err(dev, "EA Entry Size (%d) does not match length read (%d)\n",
ent_size, ent_offset - offset);
goto out;
}
res->name = pci_name(dev);
res->start = start;
res->end = end;
res->flags = flags;
if (bei <= PCI_EA_BEI_BAR5)
pci_printk(KERN_DEBUG, dev, "BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n",
bei, res, prop);
else if (bei == PCI_EA_BEI_ROM)
pci_printk(KERN_DEBUG, dev, "ROM: %pR (from Enhanced Allocation, properties %#02x)\n",
res, prop);
else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5)
pci_printk(KERN_DEBUG, dev, "VF BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n",
bei - PCI_EA_BEI_VF_BAR0, res, prop);
else
pci_printk(KERN_DEBUG, dev, "BEI %d res: %pR (from Enhanced Allocation, properties %#02x)\n",
bei, res, prop);
out:
return offset + ent_size;
}
/* Enhanced Allocation Initialization */
void pci_ea_init(struct pci_dev *dev)
{
int ea;
u8 num_ent;
int offset;
int i;
/* find PCI EA capability in list */
ea = pci_find_capability(dev, PCI_CAP_ID_EA);
if (!ea)
return;
/* determine the number of entries */
pci_bus_read_config_byte(dev->bus, dev->devfn, ea + PCI_EA_NUM_ENT,
&num_ent);
num_ent &= PCI_EA_NUM_ENT_MASK;
offset = ea + PCI_EA_FIRST_ENT;
/* Skip DWORD 2 for type 1 functions */
if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
offset += 4;
/* parse each EA entry */
for (i = 0; i < num_ent; ++i)
offset = pci_ea_read(dev, offset);
}
static void pci_add_saved_cap(struct pci_dev *pci_dev,
struct pci_cap_saved_state *new_cap)
{
hlist_add_head(&new_cap->next, &pci_dev->saved_cap_space);
}
/**
* _pci_add_cap_save_buffer - allocate buffer for saving given
* capability registers
* @dev: the PCI device
* @cap: the capability to allocate the buffer for
* @extended: Standard or Extended capability ID
* @size: requested size of the buffer
*/
static int _pci_add_cap_save_buffer(struct pci_dev *dev, u16 cap,
bool extended, unsigned int size)
{
int pos;
struct pci_cap_saved_state *save_state;
if (extended)
pos = pci_find_ext_capability(dev, cap);
else
pos = pci_find_capability(dev, cap);
if (!pos)
return 0;
save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL);
if (!save_state)
return -ENOMEM;
save_state->cap.cap_nr = cap;
save_state->cap.cap_extended = extended;
save_state->cap.size = size;
pci_add_saved_cap(dev, save_state);
return 0;
}
int pci_add_cap_save_buffer(struct pci_dev *dev, char cap, unsigned int size)
{
return _pci_add_cap_save_buffer(dev, cap, false, size);
}
int pci_add_ext_cap_save_buffer(struct pci_dev *dev, u16 cap, unsigned int size)
{
return _pci_add_cap_save_buffer(dev, cap, true, size);
}
/**
* pci_allocate_cap_save_buffers - allocate buffers for saving capabilities
* @dev: the PCI device
*/
void pci_allocate_cap_save_buffers(struct pci_dev *dev)
{
int error;
error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP,
PCI_EXP_SAVE_REGS * sizeof(u16));
if (error)
pci_err(dev, "unable to preallocate PCI Express save buffer\n");
error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16));
if (error)
pci_err(dev, "unable to preallocate PCI-X save buffer\n");
pci_allocate_vc_save_buffers(dev);
}
void pci_free_cap_save_buffers(struct pci_dev *dev)
{
struct pci_cap_saved_state *tmp;
struct hlist_node *n;
hlist_for_each_entry_safe(tmp, n, &dev->saved_cap_space, next)
kfree(tmp);
}
/**
* pci_configure_ari - enable or disable ARI forwarding
* @dev: the PCI device
*
* If @dev and its upstream bridge both support ARI, enable ARI in the
* bridge. Otherwise, disable ARI in the bridge.
*/
void pci_configure_ari(struct pci_dev *dev)
{
u32 cap;
struct pci_dev *bridge;
if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn)
return;
bridge = dev->bus->self;
if (!bridge)
return;
pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
if (!(cap & PCI_EXP_DEVCAP2_ARI))
return;
if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) {
pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2,
PCI_EXP_DEVCTL2_ARI);
bridge->ari_enabled = 1;
} else {
pcie_capability_clear_word(bridge, PCI_EXP_DEVCTL2,
PCI_EXP_DEVCTL2_ARI);
bridge->ari_enabled = 0;
}
}
static int pci_acs_enable;
/**
* pci_request_acs - ask for ACS to be enabled if supported
*/
void pci_request_acs(void)
{
pci_acs_enable = 1;
}
/**
* pci_std_enable_acs - enable ACS on devices using standard ACS capabilites
* @dev: the PCI device
*/
static void pci_std_enable_acs(struct pci_dev *dev)
{
int pos;
u16 cap;
u16 ctrl;
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
if (!pos)
return;
pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
/* Source Validation */
ctrl |= (cap & PCI_ACS_SV);
/* P2P Request Redirect */
ctrl |= (cap & PCI_ACS_RR);
/* P2P Completion Redirect */
ctrl |= (cap & PCI_ACS_CR);
/* Upstream Forwarding */
ctrl |= (cap & PCI_ACS_UF);
pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
}
/**
* pci_enable_acs - enable ACS if hardware support it
* @dev: the PCI device
*/
void pci_enable_acs(struct pci_dev *dev)
{
if (!pci_acs_enable)
return;
if (!pci_dev_specific_enable_acs(dev))
return;
pci_std_enable_acs(dev);
}
static bool pci_acs_flags_enabled(struct pci_dev *pdev, u16 acs_flags)
{
int pos;
u16 cap, ctrl;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ACS);
if (!pos)
return false;
/*
* Except for egress control, capabilities are either required
* or only required if controllable. Features missing from the
* capability field can therefore be assumed as hard-wired enabled.
*/
pci_read_config_word(pdev, pos + PCI_ACS_CAP, &cap);
acs_flags &= (cap | PCI_ACS_EC);
pci_read_config_word(pdev, pos + PCI_ACS_CTRL, &ctrl);
return (ctrl & acs_flags) == acs_flags;
}
/**
* pci_acs_enabled - test ACS against required flags for a given device
* @pdev: device to test
* @acs_flags: required PCI ACS flags
*
* Return true if the device supports the provided flags. Automatically
* filters out flags that are not implemented on multifunction devices.
*
* Note that this interface checks the effective ACS capabilities of the
* device rather than the actual capabilities. For instance, most single
* function endpoints are not required to support ACS because they have no
* opportunity for peer-to-peer access. We therefore return 'true'
* regardless of whether the device exposes an ACS capability. This makes
* it much easier for callers of this function to ignore the actual type
* or topology of the device when testing ACS support.
*/
bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags)
{
int ret;
ret = pci_dev_specific_acs_enabled(pdev, acs_flags);
if (ret >= 0)
return ret > 0;
/*
* Conventional PCI and PCI-X devices never support ACS, either
* effectively or actually. The shared bus topology implies that
* any device on the bus can receive or snoop DMA.
*/
if (!pci_is_pcie(pdev))
return false;
switch (pci_pcie_type(pdev)) {
/*
* PCI/X-to-PCIe bridges are not specifically mentioned by the spec,
* but since their primary interface is PCI/X, we conservatively
* handle them as we would a non-PCIe device.
*/
case PCI_EXP_TYPE_PCIE_BRIDGE:
/*
* PCIe 3.0, 6.12.1 excludes ACS on these devices. "ACS is never
* applicable... must never implement an ACS Extended Capability...".
* This seems arbitrary, but we take a conservative interpretation
* of this statement.
*/
case PCI_EXP_TYPE_PCI_BRIDGE:
case PCI_EXP_TYPE_RC_EC:
return false;
/*
* PCIe 3.0, 6.12.1.1 specifies that downstream and root ports should
* implement ACS in order to indicate their peer-to-peer capabilities,
* regardless of whether they are single- or multi-function devices.
*/
case PCI_EXP_TYPE_DOWNSTREAM:
case PCI_EXP_TYPE_ROOT_PORT:
return pci_acs_flags_enabled(pdev, acs_flags);
/*
* PCIe 3.0, 6.12.1.2 specifies ACS capabilities that should be
* implemented by the remaining PCIe types to indicate peer-to-peer
* capabilities, but only when they are part of a multifunction
* device. The footnote for section 6.12 indicates the specific
* PCIe types included here.
*/
case PCI_EXP_TYPE_ENDPOINT:
case PCI_EXP_TYPE_UPSTREAM:
case PCI_EXP_TYPE_LEG_END:
case PCI_EXP_TYPE_RC_END:
if (!pdev->multifunction)
break;
return pci_acs_flags_enabled(pdev, acs_flags);
}
/*
* PCIe 3.0, 6.12.1.3 specifies no ACS capabilities are applicable
* to single function devices with the exception of downstream ports.
*/
return true;
}
/**
* pci_acs_path_enable - test ACS flags from start to end in a hierarchy
* @start: starting downstream device
* @end: ending upstream device or NULL to search to the root bus
* @acs_flags: required flags
*
* Walk up a device tree from start to end testing PCI ACS support. If
* any step along the way does not support the required flags, return false.
*/
bool pci_acs_path_enabled(struct pci_dev *start,
struct pci_dev *end, u16 acs_flags)
{
struct pci_dev *pdev, *parent = start;
do {
pdev = parent;
if (!pci_acs_enabled(pdev, acs_flags))
return false;
if (pci_is_root_bus(pdev->bus))
return (end == NULL);
parent = pdev->bus->self;
} while (pdev != end);
return true;
}
/**
* pci_rebar_find_pos - find position of resize ctrl reg for BAR
* @pdev: PCI device
* @bar: BAR to find
*
* Helper to find the position of the ctrl register for a BAR.
* Returns -ENOTSUPP if resizable BARs are not supported at all.
* Returns -ENOENT if no ctrl register for the BAR could be found.
*/
static int pci_rebar_find_pos(struct pci_dev *pdev, int bar)
{
unsigned int pos, nbars, i;
u32 ctrl;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
if (!pos)
return -ENOTSUPP;
pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >>
PCI_REBAR_CTRL_NBAR_SHIFT;
for (i = 0; i < nbars; i++, pos += 8) {
int bar_idx;
pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX;
if (bar_idx == bar)
return pos;
}
return -ENOENT;
}
/**
* pci_rebar_get_possible_sizes - get possible sizes for BAR
* @pdev: PCI device
* @bar: BAR to query
*
* Get the possible sizes of a resizable BAR as bitmask defined in the spec
* (bit 0=1MB, bit 19=512GB). Returns 0 if BAR isn't resizable.
*/
u32 pci_rebar_get_possible_sizes(struct pci_dev *pdev, int bar)
{
int pos;
u32 cap;
pos = pci_rebar_find_pos(pdev, bar);
if (pos < 0)
return 0;
pci_read_config_dword(pdev, pos + PCI_REBAR_CAP, &cap);
return (cap & PCI_REBAR_CAP_SIZES) >> 4;
}
/**
* pci_rebar_get_current_size - get the current size of a BAR
* @pdev: PCI device
* @bar: BAR to set size to
*
* Read the size of a BAR from the resizable BAR config.
* Returns size if found or negative error code.
*/
int pci_rebar_get_current_size(struct pci_dev *pdev, int bar)
{
int pos;
u32 ctrl;
pos = pci_rebar_find_pos(pdev, bar);
if (pos < 0)
return pos;
pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
return (ctrl & PCI_REBAR_CTRL_BAR_SIZE) >> 8;
}
/**
* pci_rebar_set_size - set a new size for a BAR
* @pdev: PCI device
* @bar: BAR to set size to
* @size: new size as defined in the spec (0=1MB, 19=512GB)
*
* Set the new size of a BAR as defined in the spec.
* Returns zero if resizing was successful, error code otherwise.
*/
int pci_rebar_set_size(struct pci_dev *pdev, int bar, int size)
{
int pos;
u32 ctrl;
pos = pci_rebar_find_pos(pdev, bar);
if (pos < 0)
return pos;
pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE;
ctrl |= size << 8;
pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
return 0;
}
/**
* pci_enable_atomic_ops_to_root - enable AtomicOp requests to root port
* @dev: the PCI device
* @cap_mask: mask of desired AtomicOp sizes, including one or more of:
* PCI_EXP_DEVCAP2_ATOMIC_COMP32
* PCI_EXP_DEVCAP2_ATOMIC_COMP64
* PCI_EXP_DEVCAP2_ATOMIC_COMP128
*
* Return 0 if all upstream bridges support AtomicOp routing, egress
* blocking is disabled on all upstream ports, and the root port supports
* the requested completion capabilities (32-bit, 64-bit and/or 128-bit
* AtomicOp completion), or negative otherwise.
*/
int pci_enable_atomic_ops_to_root(struct pci_dev *dev, u32 cap_mask)
{
struct pci_bus *bus = dev->bus;
struct pci_dev *bridge;
u32 cap, ctl2;
if (!pci_is_pcie(dev))
return -EINVAL;
/*
* Per PCIe r4.0, sec 6.15, endpoints and root ports may be
* AtomicOp requesters. For now, we only support endpoints as
* requesters and root ports as completers. No endpoints as
* completers, and no peer-to-peer.
*/
switch (pci_pcie_type(dev)) {
case PCI_EXP_TYPE_ENDPOINT:
case PCI_EXP_TYPE_LEG_END:
case PCI_EXP_TYPE_RC_END:
break;
default:
return -EINVAL;
}
while (bus->parent) {
bridge = bus->self;
pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
switch (pci_pcie_type(bridge)) {
/* Ensure switch ports support AtomicOp routing */
case PCI_EXP_TYPE_UPSTREAM:
case PCI_EXP_TYPE_DOWNSTREAM:
if (!(cap & PCI_EXP_DEVCAP2_ATOMIC_ROUTE))
return -EINVAL;
break;
/* Ensure root port supports all the sizes we care about */
case PCI_EXP_TYPE_ROOT_PORT:
if ((cap & cap_mask) != cap_mask)
return -EINVAL;
break;
}
/* Ensure upstream ports don't block AtomicOps on egress */
if (!bridge->has_secondary_link) {
pcie_capability_read_dword(bridge, PCI_EXP_DEVCTL2,
&ctl2);
if (ctl2 & PCI_EXP_DEVCTL2_ATOMIC_EGRESS_BLOCK)
return -EINVAL;
}
bus = bus->parent;
}
pcie_capability_set_word(dev, PCI_EXP_DEVCTL2,
PCI_EXP_DEVCTL2_ATOMIC_REQ);
return 0;
}
EXPORT_SYMBOL(pci_enable_atomic_ops_to_root);
/**
* pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
* @dev: the PCI device
* @pin: the INTx pin (1=INTA, 2=INTB, 3=INTC, 4=INTD)
*
* Perform INTx swizzling for a device behind one level of bridge. This is
* required by section 9.1 of the PCI-to-PCI bridge specification for devices
* behind bridges on add-in cards. For devices with ARI enabled, the slot
* number is always 0 (see the Implementation Note in section 2.2.8.1 of
* the PCI Express Base Specification, Revision 2.1)
*/
u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin)
{
int slot;
if (pci_ari_enabled(dev->bus))
slot = 0;
else
slot = PCI_SLOT(dev->devfn);
return (((pin - 1) + slot) % 4) + 1;
}
int pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
{
u8 pin;
pin = dev->pin;
if (!pin)
return -1;
while (!pci_is_root_bus(dev->bus)) {
pin = pci_swizzle_interrupt_pin(dev, pin);
dev = dev->bus->self;
}
*bridge = dev;
return pin;
}
/**
* pci_common_swizzle - swizzle INTx all the way to root bridge
* @dev: the PCI device
* @pinp: pointer to the INTx pin value (1=INTA, 2=INTB, 3=INTD, 4=INTD)
*
* Perform INTx swizzling for a device. This traverses through all PCI-to-PCI
* bridges all the way up to a PCI root bus.
*/
u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp)
{
u8 pin = *pinp;
while (!pci_is_root_bus(dev->bus)) {
pin = pci_swizzle_interrupt_pin(dev, pin);
dev = dev->bus->self;
}
*pinp = pin;
return PCI_SLOT(dev->devfn);
}
EXPORT_SYMBOL_GPL(pci_common_swizzle);
/**
* pci_release_region - Release a PCI bar
* @pdev: PCI device whose resources were previously reserved by pci_request_region
* @bar: BAR to release
*
* Releases the PCI I/O and memory resources previously reserved by a
* successful call to pci_request_region. Call this function only
* after all use of the PCI regions has ceased.
*/
void pci_release_region(struct pci_dev *pdev, int bar)
{
struct pci_devres *dr;
if (pci_resource_len(pdev, bar) == 0)
return;
if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
release_region(pci_resource_start(pdev, bar),
pci_resource_len(pdev, bar));
else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
release_mem_region(pci_resource_start(pdev, bar),
pci_resource_len(pdev, bar));
dr = find_pci_dr(pdev);
if (dr)
dr->region_mask &= ~(1 << bar);
}
EXPORT_SYMBOL(pci_release_region);
/**
* __pci_request_region - Reserved PCI I/O and memory resource
* @pdev: PCI device whose resources are to be reserved
* @bar: BAR to be reserved
* @res_name: Name to be associated with resource.
* @exclusive: whether the region access is exclusive or not
*
* Mark the PCI region associated with PCI device @pdev BR @bar as
* being reserved by owner @res_name. Do not access any
* address inside the PCI regions unless this call returns
* successfully.
*
* If @exclusive is set, then the region is marked so that userspace
* is explicitly not allowed to map the resource via /dev/mem or
* sysfs MMIO access.
*
* Returns 0 on success, or %EBUSY on error. A warning
* message is also printed on failure.
*/
static int __pci_request_region(struct pci_dev *pdev, int bar,
const char *res_name, int exclusive)
{
struct pci_devres *dr;
if (pci_resource_len(pdev, bar) == 0)
return 0;
if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
if (!request_region(pci_resource_start(pdev, bar),
pci_resource_len(pdev, bar), res_name))
goto err_out;
} else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
if (!__request_mem_region(pci_resource_start(pdev, bar),
pci_resource_len(pdev, bar), res_name,
exclusive))
goto err_out;
}
dr = find_pci_dr(pdev);
if (dr)
dr->region_mask |= 1 << bar;
return 0;
err_out:
pci_warn(pdev, "BAR %d: can't reserve %pR\n", bar,
&pdev->resource[bar]);
return -EBUSY;
}
/**
* pci_request_region - Reserve PCI I/O and memory resource
* @pdev: PCI device whose resources are to be reserved
* @bar: BAR to be reserved
* @res_name: Name to be associated with resource
*
* Mark the PCI region associated with PCI device @pdev BAR @bar as
* being reserved by owner @res_name. Do not access any
* address inside the PCI regions unless this call returns
* successfully.
*
* Returns 0 on success, or %EBUSY on error. A warning
* message is also printed on failure.
*/
int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
{
return __pci_request_region(pdev, bar, res_name, 0);
}
EXPORT_SYMBOL(pci_request_region);
/**
* pci_request_region_exclusive - Reserved PCI I/O and memory resource
* @pdev: PCI device whose resources are to be reserved
* @bar: BAR to be reserved
* @res_name: Name to be associated with resource.
*
* Mark the PCI region associated with PCI device @pdev BR @bar as
* being reserved by owner @res_name. Do not access any
* address inside the PCI regions unless this call returns
* successfully.
*
* Returns 0 on success, or %EBUSY on error. A warning
* message is also printed on failure.
*
* The key difference that _exclusive makes it that userspace is
* explicitly not allowed to map the resource via /dev/mem or
* sysfs.
*/
int pci_request_region_exclusive(struct pci_dev *pdev, int bar,
const char *res_name)
{
return __pci_request_region(pdev, bar, res_name, IORESOURCE_EXCLUSIVE);
}
EXPORT_SYMBOL(pci_request_region_exclusive);
/**
* pci_release_selected_regions - Release selected PCI I/O and memory resources
* @pdev: PCI device whose resources were previously reserved
* @bars: Bitmask of BARs to be released
*
* Release selected PCI I/O and memory resources previously reserved.
* Call this function only after all use of the PCI regions has ceased.
*/
void pci_release_selected_regions(struct pci_dev *pdev, int bars)
{
int i;
for (i = 0; i < 6; i++)
if (bars & (1 << i))
pci_release_region(pdev, i);
}
EXPORT_SYMBOL(pci_release_selected_regions);
static int __pci_request_selected_regions(struct pci_dev *pdev, int bars,
const char *res_name, int excl)
{
int i;
for (i = 0; i < 6; i++)
if (bars & (1 << i))
if (__pci_request_region(pdev, i, res_name, excl))
goto err_out;
return 0;
err_out:
while (--i >= 0)
if (bars & (1 << i))
pci_release_region(pdev, i);
return -EBUSY;
}
/**
* pci_request_selected_regions - Reserve selected PCI I/O and memory resources
* @pdev: PCI device whose resources are to be reserved
* @bars: Bitmask of BARs to be requested
* @res_name: Name to be associated with resource
*/
int pci_request_selected_regions(struct pci_dev *pdev, int bars,
const char *res_name)
{
return __pci_request_selected_regions(pdev, bars, res_name, 0);
}
EXPORT_SYMBOL(pci_request_selected_regions);
int pci_request_selected_regions_exclusive(struct pci_dev *pdev, int bars,
const char *res_name)
{
return __pci_request_selected_regions(pdev, bars, res_name,
IORESOURCE_EXCLUSIVE);
}
EXPORT_SYMBOL(pci_request_selected_regions_exclusive);
/**
* pci_release_regions - Release reserved PCI I/O and memory resources
* @pdev: PCI device whose resources were previously reserved by pci_request_regions
*
* Releases all PCI I/O and memory resources previously reserved by a
* successful call to pci_request_regions. Call this function only
* after all use of the PCI regions has ceased.
*/
void pci_release_regions(struct pci_dev *pdev)
{
pci_release_selected_regions(pdev, (1 << 6) - 1);
}
EXPORT_SYMBOL(pci_release_regions);
/**
* pci_request_regions - Reserved PCI I/O and memory resources
* @pdev: PCI device whose resources are to be reserved
* @res_name: Name to be associated with resource.
*
* Mark all PCI regions associated with PCI device @pdev as
* being reserved by owner @res_name. Do not access any
* address inside the PCI regions unless this call returns
* successfully.
*
* Returns 0 on success, or %EBUSY on error. A warning
* message is also printed on failure.
*/
int pci_request_regions(struct pci_dev *pdev, const char *res_name)
{
return pci_request_selected_regions(pdev, ((1 << 6) - 1), res_name);
}
EXPORT_SYMBOL(pci_request_regions);
/**
* pci_request_regions_exclusive - Reserved PCI I/O and memory resources
* @pdev: PCI device whose resources are to be reserved
* @res_name: Name to be associated with resource.
*
* Mark all PCI regions associated with PCI device @pdev as
* being reserved by owner @res_name. Do not access any
* address inside the PCI regions unless this call returns
* successfully.
*
* pci_request_regions_exclusive() will mark the region so that
* /dev/mem and the sysfs MMIO access will not be allowed.
*
* Returns 0 on success, or %EBUSY on error. A warning
* message is also printed on failure.
*/
int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
{
return pci_request_selected_regions_exclusive(pdev,
((1 << 6) - 1), res_name);
}
EXPORT_SYMBOL(pci_request_regions_exclusive);
#ifdef PCI_IOBASE
struct io_range {
struct list_head list;
phys_addr_t start;
resource_size_t size;
};
static LIST_HEAD(io_range_list);
static DEFINE_SPINLOCK(io_range_lock);
#endif
/*
* Record the PCI IO range (expressed as CPU physical address + size).
* Return a negative value if an error has occured, zero otherwise
*/
int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)
{
int err = 0;
#ifdef PCI_IOBASE
struct io_range *range;
resource_size_t allocated_size = 0;
/* check if the range hasn't been previously recorded */
spin_lock(&io_range_lock);
list_for_each_entry(range, &io_range_list, list) {
if (addr >= range->start && addr + size <= range->start + size) {
/* range already registered, bail out */
goto end_register;
}
allocated_size += range->size;
}
/* range not registed yet, check for available space */
if (allocated_size + size - 1 > IO_SPACE_LIMIT) {
/* if it's too big check if 64K space can be reserved */
if (allocated_size + SZ_64K - 1 > IO_SPACE_LIMIT) {
err = -E2BIG;
goto end_register;
}
size = SZ_64K;
pr_warn("Requested IO range too big, new size set to 64K\n");
}
/* add the range to the list */
range = kzalloc(sizeof(*range), GFP_ATOMIC);
if (!range) {
err = -ENOMEM;
goto end_register;
}
range->start = addr;
range->size = size;
list_add_tail(&range->list, &io_range_list);
end_register:
spin_unlock(&io_range_lock);
#endif
return err;
}
phys_addr_t pci_pio_to_address(unsigned long pio)
{
phys_addr_t address = (phys_addr_t)OF_BAD_ADDR;
#ifdef PCI_IOBASE
struct io_range *range;
resource_size_t allocated_size = 0;
if (pio > IO_SPACE_LIMIT)
return address;
spin_lock(&io_range_lock);
list_for_each_entry(range, &io_range_list, list) {
if (pio >= allocated_size && pio < allocated_size + range->size) {
address = range->start + pio - allocated_size;
break;
}
allocated_size += range->size;
}
spin_unlock(&io_range_lock);
#endif
return address;
}
unsigned long __weak pci_address_to_pio(phys_addr_t address)
{
#ifdef PCI_IOBASE
struct io_range *res;
resource_size_t offset = 0;
unsigned long addr = -1;
spin_lock(&io_range_lock);
list_for_each_entry(res, &io_range_list, list) {
if (address >= res->start && address < res->start + res->size) {
addr = address - res->start + offset;
break;
}
offset += res->size;
}
spin_unlock(&io_range_lock);
return addr;
#else
if (address > IO_SPACE_LIMIT)
return (unsigned long)-1;
return (unsigned long) address;
#endif
}
/**
* pci_remap_iospace - Remap the memory mapped I/O space
* @res: Resource describing the I/O space
* @phys_addr: physical address of range to be mapped
*
* Remap the memory mapped I/O space described by the @res
* and the CPU physical address @phys_addr into virtual address space.
* Only architectures that have memory mapped IO functions defined
* (and the PCI_IOBASE value defined) should call this function.
*/
int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
{
#if defined(PCI_IOBASE) && defined(CONFIG_MMU)
unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
if (!(res->flags & IORESOURCE_IO))
return -EINVAL;
if (res->end > IO_SPACE_LIMIT)
return -EINVAL;
return ioremap_page_range(vaddr, vaddr + resource_size(res), phys_addr,
pgprot_device(PAGE_KERNEL));
#else
/* this architecture does not have memory mapped I/O space,
so this function should never be called */
WARN_ONCE(1, "This architecture does not support memory mapped I/O\n");
return -ENODEV;
#endif
}
EXPORT_SYMBOL(pci_remap_iospace);
/**
* pci_unmap_iospace - Unmap the memory mapped I/O space
* @res: resource to be unmapped
*
* Unmap the CPU virtual address @res from virtual address space.
* Only architectures that have memory mapped IO functions defined
* (and the PCI_IOBASE value defined) should call this function.
*/
void pci_unmap_iospace(struct resource *res)
{
#if defined(PCI_IOBASE) && defined(CONFIG_MMU)
unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
unmap_kernel_range(vaddr, resource_size(res));
#endif
}
EXPORT_SYMBOL(pci_unmap_iospace);
/**
* devm_pci_remap_cfgspace - Managed pci_remap_cfgspace()
* @dev: Generic device to remap IO address for
* @offset: Resource address to map
* @size: Size of map
*
* Managed pci_remap_cfgspace(). Map is automatically unmapped on driver
* detach.
*/
void __iomem *devm_pci_remap_cfgspace(struct device *dev,
resource_size_t offset,
resource_size_t size)
{
void __iomem **ptr, *addr;
ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return NULL;
addr = pci_remap_cfgspace(offset, size);
if (addr) {
*ptr = addr;
devres_add(dev, ptr);
} else
devres_free(ptr);
return addr;
}
EXPORT_SYMBOL(devm_pci_remap_cfgspace);
/**
* devm_pci_remap_cfg_resource - check, request region and ioremap cfg resource
* @dev: generic device to handle the resource for
* @res: configuration space resource to be handled
*
* Checks that a resource is a valid memory region, requests the memory
* region and ioremaps with pci_remap_cfgspace() API that ensures the
* proper PCI configuration space memory attributes are guaranteed.
*
* All operations are managed and will be undone on driver detach.
*
* Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
* on failure. Usage example::
*
* res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
* base = devm_pci_remap_cfg_resource(&pdev->dev, res);
* if (IS_ERR(base))
* return PTR_ERR(base);
*/
void __iomem *devm_pci_remap_cfg_resource(struct device *dev,
struct resource *res)
{
resource_size_t size;
const char *name;
void __iomem *dest_ptr;
BUG_ON(!dev);
if (!res || resource_type(res) != IORESOURCE_MEM) {
dev_err(dev, "invalid resource\n");
return IOMEM_ERR_PTR(-EINVAL);
}
size = resource_size(res);
name = res->name ?: dev_name(dev);
if (!devm_request_mem_region(dev, res->start, size, name)) {
dev_err(dev, "can't request region for resource %pR\n", res);
return IOMEM_ERR_PTR(-EBUSY);
}
dest_ptr = devm_pci_remap_cfgspace(dev, res->start, size);
if (!dest_ptr) {
dev_err(dev, "ioremap failed for resource %pR\n", res);
devm_release_mem_region(dev, res->start, size);
dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
}
return dest_ptr;
}
EXPORT_SYMBOL(devm_pci_remap_cfg_resource);
static void __pci_set_master(struct pci_dev *dev, bool enable)
{
u16 old_cmd, cmd;
pci_read_config_word(dev, PCI_COMMAND, &old_cmd);
if (enable)
cmd = old_cmd | PCI_COMMAND_MASTER;
else
cmd = old_cmd & ~PCI_COMMAND_MASTER;
if (cmd != old_cmd) {
pci_dbg(dev, "%s bus mastering\n",
enable ? "enabling" : "disabling");
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
dev->is_busmaster = enable;
}
/**
* pcibios_setup - process "pci=" kernel boot arguments
* @str: string used to pass in "pci=" kernel boot arguments
*
* Process kernel boot arguments. This is the default implementation.
* Architecture specific implementations can override this as necessary.
*/
char * __weak __init pcibios_setup(char *str)
{
return str;
}
/**
* pcibios_set_master - enable PCI bus-mastering for device dev
* @dev: the PCI device to enable
*
* Enables PCI bus-mastering for the device. This is the default
* implementation. Architecture specific implementations can override
* this if necessary.
*/
void __weak pcibios_set_master(struct pci_dev *dev)
{
u8 lat;
/* The latency timer doesn't apply to PCIe (either Type 0 or Type 1) */
if (pci_is_pcie(dev))
return;
pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
if (lat < 16)
lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
else if (lat > pcibios_max_latency)
lat = pcibios_max_latency;
else
return;
pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
}
/**
* pci_set_master - enables bus-mastering for device dev
* @dev: the PCI device to enable
*
* Enables bus-mastering on the device and calls pcibios_set_master()
* to do the needed arch specific settings.
*/
void pci_set_master(struct pci_dev *dev)
{
__pci_set_master(dev, true);
pcibios_set_master(dev);
}
EXPORT_SYMBOL(pci_set_master);
/**
* pci_clear_master - disables bus-mastering for device dev
* @dev: the PCI device to disable
*/
void pci_clear_master(struct pci_dev *dev)
{
__pci_set_master(dev, false);
}
EXPORT_SYMBOL(pci_clear_master);
/**
* pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed
* @dev: the PCI device for which MWI is to be enabled
*
* Helper function for pci_set_mwi.
* Originally copied from drivers/net/acenic.c.
* Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>.
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
int pci_set_cacheline_size(struct pci_dev *dev)
{
u8 cacheline_size;
if (!pci_cache_line_size)
return -EINVAL;
/* Validate current setting: the PCI_CACHE_LINE_SIZE must be
equal to or multiple of the right value. */
pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
if (cacheline_size >= pci_cache_line_size &&
(cacheline_size % pci_cache_line_size) == 0)
return 0;
/* Write the correct value. */
pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size);
/* Read it back. */
pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size);
if (cacheline_size == pci_cache_line_size)
return 0;
pci_printk(KERN_DEBUG, dev, "cache line size of %d is not supported\n",
pci_cache_line_size << 2);
return -EINVAL;
}
EXPORT_SYMBOL_GPL(pci_set_cacheline_size);
/**
* pci_set_mwi - enables memory-write-invalidate PCI transaction
* @dev: the PCI device for which MWI is enabled
*
* Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
int pci_set_mwi(struct pci_dev *dev)
{
#ifdef PCI_DISABLE_MWI
return 0;
#else
int rc;
u16 cmd;
rc = pci_set_cacheline_size(dev);
if (rc)
return rc;
pci_read_config_word(dev, PCI_COMMAND, &cmd);
if (!(cmd & PCI_COMMAND_INVALIDATE)) {
pci_dbg(dev, "enabling Mem-Wr-Inval\n");
cmd |= PCI_COMMAND_INVALIDATE;
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
return 0;
#endif
}
EXPORT_SYMBOL(pci_set_mwi);
/**
* pcim_set_mwi - a device-managed pci_set_mwi()
* @dev: the PCI device for which MWI is enabled
*
* Managed pci_set_mwi().
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
int pcim_set_mwi(struct pci_dev *dev)
{
struct pci_devres *dr;
dr = find_pci_dr(dev);
if (!dr)
return -ENOMEM;
dr->mwi = 1;
return pci_set_mwi(dev);
}
EXPORT_SYMBOL(pcim_set_mwi);
/**
* pci_try_set_mwi - enables memory-write-invalidate PCI transaction
* @dev: the PCI device for which MWI is enabled
*
* Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
* Callers are not required to check the return value.
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
int pci_try_set_mwi(struct pci_dev *dev)
{
#ifdef PCI_DISABLE_MWI
return 0;
#else
return pci_set_mwi(dev);
#endif
}
EXPORT_SYMBOL(pci_try_set_mwi);
/**
* pci_clear_mwi - disables Memory-Write-Invalidate for device dev
* @dev: the PCI device to disable
*
* Disables PCI Memory-Write-Invalidate transaction on the device
*/
void pci_clear_mwi(struct pci_dev *dev)
{
#ifndef PCI_DISABLE_MWI
u16 cmd;
pci_read_config_word(dev, PCI_COMMAND, &cmd);
if (cmd & PCI_COMMAND_INVALIDATE) {
cmd &= ~PCI_COMMAND_INVALIDATE;
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
#endif
}
EXPORT_SYMBOL(pci_clear_mwi);
/**
* pci_intx - enables/disables PCI INTx for device dev
* @pdev: the PCI device to operate on
* @enable: boolean: whether to enable or disable PCI INTx
*
* Enables/disables PCI INTx for device dev
*/
void pci_intx(struct pci_dev *pdev, int enable)
{
u16 pci_command, new;
pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
if (enable)
new = pci_command & ~PCI_COMMAND_INTX_DISABLE;
else
new = pci_command | PCI_COMMAND_INTX_DISABLE;
if (new != pci_command) {
struct pci_devres *dr;
pci_write_config_word(pdev, PCI_COMMAND, new);
dr = find_pci_dr(pdev);
if (dr && !dr->restore_intx) {
dr->restore_intx = 1;
dr->orig_intx = !enable;
}
}
}
EXPORT_SYMBOL_GPL(pci_intx);
static bool pci_check_and_set_intx_mask(struct pci_dev *dev, bool mask)
{
struct pci_bus *bus = dev->bus;
bool mask_updated = true;
u32 cmd_status_dword;
u16 origcmd, newcmd;
unsigned long flags;
bool irq_pending;
/*
* We do a single dword read to retrieve both command and status.
* Document assumptions that make this possible.
*/
BUILD_BUG_ON(PCI_COMMAND % 4);
BUILD_BUG_ON(PCI_COMMAND + 2 != PCI_STATUS);
raw_spin_lock_irqsave(&pci_lock, flags);
bus->ops->read(bus, dev->devfn, PCI_COMMAND, 4, &cmd_status_dword);
irq_pending = (cmd_status_dword >> 16) & PCI_STATUS_INTERRUPT;
/*
* Check interrupt status register to see whether our device
* triggered the interrupt (when masking) or the next IRQ is
* already pending (when unmasking).
*/
if (mask != irq_pending) {
mask_updated = false;
goto done;
}
origcmd = cmd_status_dword;
newcmd = origcmd & ~PCI_COMMAND_INTX_DISABLE;
if (mask)
newcmd |= PCI_COMMAND_INTX_DISABLE;
if (newcmd != origcmd)
bus->ops->write(bus, dev->devfn, PCI_COMMAND, 2, newcmd);
done:
raw_spin_unlock_irqrestore(&pci_lock, flags);
return mask_updated;
}
/**
* pci_check_and_mask_intx - mask INTx on pending interrupt
* @dev: the PCI device to operate on
*
* Check if the device dev has its INTx line asserted, mask it and
* return true in that case. False is returned if no interrupt was
* pending.
*/
bool pci_check_and_mask_intx(struct pci_dev *dev)
{
return pci_check_and_set_intx_mask(dev, true);
}
EXPORT_SYMBOL_GPL(pci_check_and_mask_intx);
/**
* pci_check_and_unmask_intx - unmask INTx if no interrupt is pending
* @dev: the PCI device to operate on
*
* Check if the device dev has its INTx line asserted, unmask it if not
* and return true. False is returned and the mask remains active if
* there was still an interrupt pending.
*/
bool pci_check_and_unmask_intx(struct pci_dev *dev)
{
return pci_check_and_set_intx_mask(dev, false);
}
EXPORT_SYMBOL_GPL(pci_check_and_unmask_intx);
/**
* pci_wait_for_pending_transaction - waits for pending transaction
* @dev: the PCI device to operate on
*
* Return 0 if transaction is pending 1 otherwise.
*/
int pci_wait_for_pending_transaction(struct pci_dev *dev)
{
if (!pci_is_pcie(dev))
return 1;
return pci_wait_for_pending(dev, pci_pcie_cap(dev) + PCI_EXP_DEVSTA,
PCI_EXP_DEVSTA_TRPND);
}
EXPORT_SYMBOL(pci_wait_for_pending_transaction);
static void pci_flr_wait(struct pci_dev *dev)
{
int delay = 1, timeout = 60000;
u32 id;
/*
* Per PCIe r3.1, sec 6.6.2, a device must complete an FLR within
* 100ms, but may silently discard requests while the FLR is in
* progress. Wait 100ms before trying to access the device.
*/
msleep(100);
/*
* After 100ms, the device should not silently discard config
* requests, but it may still indicate that it needs more time by
* responding to them with CRS completions. The Root Port will
* generally synthesize ~0 data to complete the read (except when
* CRS SV is enabled and the read was for the Vendor ID; in that
* case it synthesizes 0x0001 data).
*
* Wait for the device to return a non-CRS completion. Read the
* Command register instead of Vendor ID so we don't have to
* contend with the CRS SV value.
*/
pci_read_config_dword(dev, PCI_COMMAND, &id);
while (id == ~0) {
if (delay > timeout) {
pci_warn(dev, "not ready %dms after FLR; giving up\n",
100 + delay - 1);
return;
}
if (delay > 1000)
pci_info(dev, "not ready %dms after FLR; waiting\n",
100 + delay - 1);
msleep(delay);
delay *= 2;
pci_read_config_dword(dev, PCI_COMMAND, &id);
}
if (delay > 1000)
pci_info(dev, "ready %dms after FLR\n", 100 + delay - 1);
}
/**
* pcie_has_flr - check if a device supports function level resets
* @dev: device to check
*
* Returns true if the device advertises support for PCIe function level
* resets.
*/
static bool pcie_has_flr(struct pci_dev *dev)
{
u32 cap;
if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
return false;
pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
return cap & PCI_EXP_DEVCAP_FLR;
}
/**
* pcie_flr - initiate a PCIe function level reset
* @dev: device to reset
*
* Initiate a function level reset on @dev. The caller should ensure the
* device supports FLR before calling this function, e.g. by using the
* pcie_has_flr() helper.
*/
void pcie_flr(struct pci_dev *dev)
{
if (!pci_wait_for_pending_transaction(dev))
pci_err(dev, "timed out waiting for pending transaction; performing function level reset anyway\n");
pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);
pci_flr_wait(dev);
}
EXPORT_SYMBOL_GPL(pcie_flr);
static int pci_af_flr(struct pci_dev *dev, int probe)
{
int pos;
u8 cap;
pos = pci_find_capability(dev, PCI_CAP_ID_AF);
if (!pos)
return -ENOTTY;
if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
return -ENOTTY;
pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap);
if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))
return -ENOTTY;
if (probe)
return 0;
/*
* Wait for Transaction Pending bit to clear. A word-aligned test
* is used, so we use the conrol offset rather than status and shift
* the test bit to match.
*/
if (!pci_wait_for_pending(dev, pos + PCI_AF_CTRL,
PCI_AF_STATUS_TP << 8))
pci_err(dev, "timed out waiting for pending transaction; performing AF function level reset anyway\n");
pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR);
pci_flr_wait(dev);
return 0;
}
/**
* pci_pm_reset - Put device into PCI_D3 and back into PCI_D0.
* @dev: Device to reset.
* @probe: If set, only check if the device can be reset this way.
*
* If @dev supports native PCI PM and its PCI_PM_CTRL_NO_SOFT_RESET flag is
* unset, it will be reinitialized internally when going from PCI_D3hot to
* PCI_D0. If that's the case and the device is not in a low-power state
* already, force it into PCI_D3hot and back to PCI_D0, causing it to be reset.
*
* NOTE: This causes the caller to sleep for twice the device power transition
* cooldown period, which for the D0->D3hot and D3hot->D0 transitions is 10 ms
* by default (i.e. unless the @dev's d3_delay field has a different value).
* Moreover, only devices in D0 can be reset by this function.
*/
static int pci_pm_reset(struct pci_dev *dev, int probe)
{
u16 csr;
if (!dev->pm_cap || dev->dev_flags & PCI_DEV_FLAGS_NO_PM_RESET)
return -ENOTTY;
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr);
if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
return -ENOTTY;
if (probe)
return 0;
if (dev->current_state != PCI_D0)
return -EINVAL;
csr &= ~PCI_PM_CTRL_STATE_MASK;
csr |= PCI_D3hot;
pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
pci_dev_d3_sleep(dev);
csr &= ~PCI_PM_CTRL_STATE_MASK;
csr |= PCI_D0;
pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
pci_dev_d3_sleep(dev);
return 0;
}
void pci_reset_secondary_bus(struct pci_dev *dev)
{
u16 ctrl;
pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &ctrl);
ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
/*
* PCI spec v3.0 7.6.4.2 requires minimum Trst of 1ms. Double
* this to 2ms to ensure that we meet the minimum requirement.
*/
msleep(2);
ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
/*
* Trhfa for conventional PCI is 2^25 clock cycles.
* Assuming a minimum 33MHz clock this results in a 1s
* delay before we can consider subordinate devices to
* be re-initialized. PCIe has some ways to shorten this,
* but we don't make use of them yet.
*/
ssleep(1);
}
void __weak pcibios_reset_secondary_bus(struct pci_dev *dev)
{
pci_reset_secondary_bus(dev);
}
/**
* pci_reset_bridge_secondary_bus - Reset the secondary bus on a PCI bridge.
* @dev: Bridge device
*
* Use the bridge control register to assert reset on the secondary bus.
* Devices on the secondary bus are left in power-on state.
*/
void pci_reset_bridge_secondary_bus(struct pci_dev *dev)
{
pcibios_reset_secondary_bus(dev);
}
EXPORT_SYMBOL_GPL(pci_reset_bridge_secondary_bus);
static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
{
struct pci_dev *pdev;
if (pci_is_root_bus(dev->bus) || dev->subordinate ||
!dev->bus->self || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
return -ENOTTY;
list_for_each_entry(pdev, &dev->bus->devices, bus_list)
if (pdev != dev)
return -ENOTTY;
if (probe)
return 0;
pci_reset_bridge_secondary_bus(dev->bus->self);
return 0;
}
static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe)
{
int rc = -ENOTTY;
if (!hotplug || !try_module_get(hotplug->ops->owner))
return rc;
if (hotplug->ops->reset_slot)
rc = hotplug->ops->reset_slot(hotplug, probe);
module_put(hotplug->ops->owner);
return rc;
}
static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
{
struct pci_dev *pdev;
if (dev->subordinate || !dev->slot ||
dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
return -ENOTTY;
list_for_each_entry(pdev, &dev->bus->devices, bus_list)
if (pdev != dev && pdev->slot == dev->slot)
return -ENOTTY;
return pci_reset_hotplug_slot(dev->slot->hotplug, probe);
}
static void pci_dev_lock(struct pci_dev *dev)
{
pci_cfg_access_lock(dev);
/* block PM suspend, driver probe, etc. */
device_lock(&dev->dev);
}
/* Return 1 on successful lock, 0 on contention */
static int pci_dev_trylock(struct pci_dev *dev)
{
if (pci_cfg_access_trylock(dev)) {
if (device_trylock(&dev->dev))
return 1;
pci_cfg_access_unlock(dev);
}
return 0;
}
static void pci_dev_unlock(struct pci_dev *dev)
{
device_unlock(&dev->dev);
pci_cfg_access_unlock(dev);
}
static void pci_dev_save_and_disable(struct pci_dev *dev)
{
const struct pci_error_handlers *err_handler =
dev->driver ? dev->driver->err_handler : NULL;
/*
* dev->driver->err_handler->reset_prepare() is protected against
* races with ->remove() by the device lock, which must be held by
* the caller.
*/
if (err_handler && err_handler->reset_prepare)
err_handler->reset_prepare(dev);
/*
* Wake-up device prior to save. PM registers default to D0 after
* reset and a simple register restore doesn't reliably return
* to a non-D0 state anyway.
*/
pci_set_power_state(dev, PCI_D0);
pci_save_state(dev);
/*
* Disable the device by clearing the Command register, except for
* INTx-disable which is set. This not only disables MMIO and I/O port
* BARs, but also prevents the device from being Bus Master, preventing
* DMA from the device including MSI/MSI-X interrupts. For PCI 2.3
* compliant devices, INTx-disable prevents legacy interrupts.
*/
pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
}
static void pci_dev_restore(struct pci_dev *dev)
{
const struct pci_error_handlers *err_handler =
dev->driver ? dev->driver->err_handler : NULL;
pci_restore_state(dev);
/*
* dev->driver->err_handler->reset_done() is protected against
* races with ->remove() by the device lock, which must be held by
* the caller.
*/
if (err_handler && err_handler->reset_done)
err_handler->reset_done(dev);
}
/**
* __pci_reset_function_locked - reset a PCI device function while holding
* the @dev mutex lock.
* @dev: PCI device to reset
*
* Some devices allow an individual function to be reset without affecting
* other functions in the same device. The PCI device must be responsive
* to PCI config space in order to use this function.
*
* The device function is presumed to be unused and the caller is holding
* the device mutex lock when this function is called.
* Resetting the device will make the contents of PCI configuration space
* random, so any caller of this must be prepared to reinitialise the
* device including MSI, bus mastering, BARs, decoding IO and memory spaces,
* etc.
*
* Returns 0 if the device function was successfully reset or negative if the
* device doesn't support resetting a single function.
*/
int __pci_reset_function_locked(struct pci_dev *dev)
{
int rc;
might_sleep();
/*
* A reset method returns -ENOTTY if it doesn't support this device
* and we should try the next method.
*
* If it returns 0 (success), we're finished. If it returns any
* other error, we're also finished: this indicates that further
* reset mechanisms might be broken on the device.
*/
rc = pci_dev_specific_reset(dev, 0);
if (rc != -ENOTTY)
return rc;
if (pcie_has_flr(dev)) {
pcie_flr(dev);
return 0;
}
rc = pci_af_flr(dev, 0);
if (rc != -ENOTTY)
return rc;
rc = pci_pm_reset(dev, 0);
if (rc != -ENOTTY)
return rc;
rc = pci_dev_reset_slot_function(dev, 0);
if (rc != -ENOTTY)
return rc;
return pci_parent_bus_reset(dev, 0);
}
EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
/**
* pci_probe_reset_function - check whether the device can be safely reset
* @dev: PCI device to reset
*
* Some devices allow an individual function to be reset without affecting
* other functions in the same device. The PCI device must be responsive
* to PCI config space in order to use this function.
*
* Returns 0 if the device function can be reset or negative if the
* device doesn't support resetting a single function.
*/
int pci_probe_reset_function(struct pci_dev *dev)
{
int rc;
might_sleep();
rc = pci_dev_specific_reset(dev, 1);
if (rc != -ENOTTY)
return rc;
if (pcie_has_flr(dev))
return 0;
rc = pci_af_flr(dev, 1);
if (rc != -ENOTTY)
return rc;
rc = pci_pm_reset(dev, 1);
if (rc != -ENOTTY)
return rc;
rc = pci_dev_reset_slot_function(dev, 1);
if (rc != -ENOTTY)
return rc;
return pci_parent_bus_reset(dev, 1);
}
/**
* pci_reset_function - quiesce and reset a PCI device function
* @dev: PCI device to reset
*
* Some devices allow an individual function to be reset without affecting
* other functions in the same device. The PCI device must be responsive
* to PCI config space in order to use this function.
*
* This function does not just reset the PCI portion of a device, but
* clears all the state associated with the device. This function differs
* from __pci_reset_function_locked() in that it saves and restores device state
* over the reset and takes the PCI device lock.
*
* Returns 0 if the device function was successfully reset or negative if the
* device doesn't support resetting a single function.
*/
int pci_reset_function(struct pci_dev *dev)
{
int rc;
rc = pci_probe_reset_function(dev);
if (rc)
return rc;
pci_dev_lock(dev);
pci_dev_save_and_disable(dev);
rc = __pci_reset_function_locked(dev);
pci_dev_restore(dev);
pci_dev_unlock(dev);
return rc;
}
EXPORT_SYMBOL_GPL(pci_reset_function);
/**
* pci_reset_function_locked - quiesce and reset a PCI device function
* @dev: PCI device to reset
*
* Some devices allow an individual function to be reset without affecting
* other functions in the same device. The PCI device must be responsive
* to PCI config space in order to use this function.
*
* This function does not just reset the PCI portion of a device, but
* clears all the state associated with the device. This function differs
* from __pci_reset_function_locked() in that it saves and restores device state
* over the reset. It also differs from pci_reset_function() in that it
* requires the PCI device lock to be held.
*
* Returns 0 if the device function was successfully reset or negative if the
* device doesn't support resetting a single function.
*/
int pci_reset_function_locked(struct pci_dev *dev)
{
int rc;
rc = pci_probe_reset_function(dev);
if (rc)
return rc;
pci_dev_save_and_disable(dev);
rc = __pci_reset_function_locked(dev);
pci_dev_restore(dev);
return rc;
}
EXPORT_SYMBOL_GPL(pci_reset_function_locked);
/**
* pci_try_reset_function - quiesce and reset a PCI device function
* @dev: PCI device to reset
*
* Same as above, except return -EAGAIN if unable to lock device.
*/
int pci_try_reset_function(struct pci_dev *dev)
{
int rc;
rc = pci_probe_reset_function(dev);
if (rc)
return rc;
if (!pci_dev_trylock(dev))
return -EAGAIN;
pci_dev_save_and_disable(dev);
rc = __pci_reset_function_locked(dev);
pci_dev_unlock(dev);
pci_dev_restore(dev);
return rc;
}
EXPORT_SYMBOL_GPL(pci_try_reset_function);
/* Do any devices on or below this bus prevent a bus reset? */
static bool pci_bus_resetable(struct pci_bus *bus)
{
struct pci_dev *dev;
if (bus->self && (bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET))
return false;
list_for_each_entry(dev, &bus->devices, bus_list) {
if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
(dev->subordinate && !pci_bus_resetable(dev->subordinate)))
return false;
}
return true;
}
/* Lock devices from the top of the tree down */
static void pci_bus_lock(struct pci_bus *bus)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
pci_dev_lock(dev);
if (dev->subordinate)
pci_bus_lock(dev->subordinate);
}
}
/* Unlock devices from the bottom of the tree up */
static void pci_bus_unlock(struct pci_bus *bus)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
if (dev->subordinate)
pci_bus_unlock(dev->subordinate);
pci_dev_unlock(dev);
}
}
/* Return 1 on successful lock, 0 on contention */
static int pci_bus_trylock(struct pci_bus *bus)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
if (!pci_dev_trylock(dev))
goto unlock;
if (dev->subordinate) {
if (!pci_bus_trylock(dev->subordinate)) {
pci_dev_unlock(dev);
goto unlock;
}
}
}
return 1;
unlock:
list_for_each_entry_continue_reverse(dev, &bus->devices, bus_list) {
if (dev->subordinate)
pci_bus_unlock(dev->subordinate);
pci_dev_unlock(dev);
}
return 0;
}
/* Do any devices on or below this slot prevent a bus reset? */
static bool pci_slot_resetable(struct pci_slot *slot)
{
struct pci_dev *dev;
if (slot->bus->self &&
(slot->bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET))
return false;
list_for_each_entry(dev, &slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
(dev->subordinate && !pci_bus_resetable(dev->subordinate)))
return false;
}
return true;
}
/* Lock devices from the top of the tree down */
static void pci_slot_lock(struct pci_slot *slot)
{
struct pci_dev *dev;
list_for_each_entry(dev, &slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
pci_dev_lock(dev);
if (dev->subordinate)
pci_bus_lock(dev->subordinate);
}
}
/* Unlock devices from the bottom of the tree up */
static void pci_slot_unlock(struct pci_slot *slot)
{
struct pci_dev *dev;
list_for_each_entry(dev, &slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
if (dev->subordinate)
pci_bus_unlock(dev->subordinate);
pci_dev_unlock(dev);
}
}
/* Return 1 on successful lock, 0 on contention */
static int pci_slot_trylock(struct pci_slot *slot)
{
struct pci_dev *dev;
list_for_each_entry(dev, &slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
if (!pci_dev_trylock(dev))
goto unlock;
if (dev->subordinate) {
if (!pci_bus_trylock(dev->subordinate)) {
pci_dev_unlock(dev);
goto unlock;
}
}
}
return 1;
unlock:
list_for_each_entry_continue_reverse(dev,
&slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
if (dev->subordinate)
pci_bus_unlock(dev->subordinate);
pci_dev_unlock(dev);
}
return 0;
}
/* Save and disable devices from the top of the tree down */
static void pci_bus_save_and_disable(struct pci_bus *bus)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
pci_dev_lock(dev);
pci_dev_save_and_disable(dev);
pci_dev_unlock(dev);
if (dev->subordinate)
pci_bus_save_and_disable(dev->subordinate);
}
}
/*
* Restore devices from top of the tree down - parent bridges need to be
* restored before we can get to subordinate devices.
*/
static void pci_bus_restore(struct pci_bus *bus)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
pci_dev_lock(dev);
pci_dev_restore(dev);
pci_dev_unlock(dev);
if (dev->subordinate)
pci_bus_restore(dev->subordinate);
}
}
/* Save and disable devices from the top of the tree down */
static void pci_slot_save_and_disable(struct pci_slot *slot)
{
struct pci_dev *dev;
list_for_each_entry(dev, &slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
pci_dev_save_and_disable(dev);
if (dev->subordinate)
pci_bus_save_and_disable(dev->subordinate);
}
}
/*
* Restore devices from top of the tree down - parent bridges need to be
* restored before we can get to subordinate devices.
*/
static void pci_slot_restore(struct pci_slot *slot)
{
struct pci_dev *dev;
list_for_each_entry(dev, &slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
pci_dev_restore(dev);
if (dev->subordinate)
pci_bus_restore(dev->subordinate);
}
}
static int pci_slot_reset(struct pci_slot *slot, int probe)
{
int rc;
if (!slot || !pci_slot_resetable(slot))
return -ENOTTY;
if (!probe)
pci_slot_lock(slot);
might_sleep();
rc = pci_reset_hotplug_slot(slot->hotplug, probe);
if (!probe)
pci_slot_unlock(slot);
return rc;
}
/**
* pci_probe_reset_slot - probe whether a PCI slot can be reset
* @slot: PCI slot to probe
*
* Return 0 if slot can be reset, negative if a slot reset is not supported.
*/
int pci_probe_reset_slot(struct pci_slot *slot)
{
return pci_slot_reset(slot, 1);
}
EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
/**
* pci_reset_slot - reset a PCI slot
* @slot: PCI slot to reset
*
* A PCI bus may host multiple slots, each slot may support a reset mechanism
* independent of other slots. For instance, some slots may support slot power
* control. In the case of a 1:1 bus to slot architecture, this function may
* wrap the bus reset to avoid spurious slot related events such as hotplug.
* Generally a slot reset should be attempted before a bus reset. All of the
* function of the slot and any subordinate buses behind the slot are reset
* through this function. PCI config space of all devices in the slot and
* behind the slot is saved before and restored after reset.
*
* Return 0 on success, non-zero on error.
*/
int pci_reset_slot(struct pci_slot *slot)
{
int rc;
rc = pci_slot_reset(slot, 1);
if (rc)
return rc;
pci_slot_save_and_disable(slot);
rc = pci_slot_reset(slot, 0);
pci_slot_restore(slot);
return rc;
}
EXPORT_SYMBOL_GPL(pci_reset_slot);
/**
* pci_try_reset_slot - Try to reset a PCI slot
* @slot: PCI slot to reset
*
* Same as above except return -EAGAIN if the slot cannot be locked
*/
int pci_try_reset_slot(struct pci_slot *slot)
{
int rc;
rc = pci_slot_reset(slot, 1);
if (rc)
return rc;
pci_slot_save_and_disable(slot);
if (pci_slot_trylock(slot)) {
might_sleep();
rc = pci_reset_hotplug_slot(slot->hotplug, 0);
pci_slot_unlock(slot);
} else
rc = -EAGAIN;
pci_slot_restore(slot);
return rc;
}
EXPORT_SYMBOL_GPL(pci_try_reset_slot);
static int pci_bus_reset(struct pci_bus *bus, int probe)
{
if (!bus->self || !pci_bus_resetable(bus))
return -ENOTTY;
if (probe)
return 0;
pci_bus_lock(bus);
might_sleep();
pci_reset_bridge_secondary_bus(bus->self);
pci_bus_unlock(bus);
return 0;
}
/**
* pci_probe_reset_bus - probe whether a PCI bus can be reset
* @bus: PCI bus to probe
*
* Return 0 if bus can be reset, negative if a bus reset is not supported.
*/
int pci_probe_reset_bus(struct pci_bus *bus)
{
return pci_bus_reset(bus, 1);
}
EXPORT_SYMBOL_GPL(pci_probe_reset_bus);
/**
* pci_reset_bus - reset a PCI bus
* @bus: top level PCI bus to reset
*
* Do a bus reset on the given bus and any subordinate buses, saving
* and restoring state of all devices.
*
* Return 0 on success, non-zero on error.
*/
int pci_reset_bus(struct pci_bus *bus)
{
int rc;
rc = pci_bus_reset(bus, 1);
if (rc)
return rc;
pci_bus_save_and_disable(bus);
rc = pci_bus_reset(bus, 0);
pci_bus_restore(bus);
return rc;
}
EXPORT_SYMBOL_GPL(pci_reset_bus);
/**
* pci_try_reset_bus - Try to reset a PCI bus
* @bus: top level PCI bus to reset
*
* Same as above except return -EAGAIN if the bus cannot be locked
*/
int pci_try_reset_bus(struct pci_bus *bus)
{
int rc;
rc = pci_bus_reset(bus, 1);
if (rc)
return rc;
pci_bus_save_and_disable(bus);
if (pci_bus_trylock(bus)) {
might_sleep();
pci_reset_bridge_secondary_bus(bus->self);
pci_bus_unlock(bus);
} else
rc = -EAGAIN;
pci_bus_restore(bus);
return rc;
}
EXPORT_SYMBOL_GPL(pci_try_reset_bus);
/**
* pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
* @dev: PCI device to query
*
* Returns mmrbc: maximum designed memory read count in bytes
* or appropriate error value.
*/
int pcix_get_max_mmrbc(struct pci_dev *dev)
{
int cap;
u32 stat;
cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!cap)
return -EINVAL;
if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
return -EINVAL;
return 512 << ((stat & PCI_X_STATUS_MAX_READ) >> 21);
}
EXPORT_SYMBOL(pcix_get_max_mmrbc);
/**
* pcix_get_mmrbc - get PCI-X maximum memory read byte count
* @dev: PCI device to query
*
* Returns mmrbc: maximum memory read count in bytes
* or appropriate error value.
*/
int pcix_get_mmrbc(struct pci_dev *dev)
{
int cap;
u16 cmd;
cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!cap)
return -EINVAL;
if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
return -EINVAL;
return 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2);
}
EXPORT_SYMBOL(pcix_get_mmrbc);
/**
* pcix_set_mmrbc - set PCI-X maximum memory read byte count
* @dev: PCI device to query
* @mmrbc: maximum memory read count in bytes
* valid values are 512, 1024, 2048, 4096
*
* If possible sets maximum memory read byte count, some bridges have erratas
* that prevent this.
*/
int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc)
{
int cap;
u32 stat, v, o;
u16 cmd;
if (mmrbc < 512 || mmrbc > 4096 || !is_power_of_2(mmrbc))
return -EINVAL;
v = ffs(mmrbc) - 10;
cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (!cap)
return -EINVAL;
if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat))
return -EINVAL;
if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21)
return -E2BIG;
if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd))
return -EINVAL;
o = (cmd & PCI_X_CMD_MAX_READ) >> 2;
if (o != v) {
if (v > o && (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MMRBC))
return -EIO;
cmd &= ~PCI_X_CMD_MAX_READ;
cmd |= v << 2;
if (pci_write_config_word(dev, cap + PCI_X_CMD, cmd))
return -EIO;
}
return 0;
}
EXPORT_SYMBOL(pcix_set_mmrbc);
/**
* pcie_get_readrq - get PCI Express read request size
* @dev: PCI device to query
*
* Returns maximum memory read request in bytes
* or appropriate error value.
*/
int pcie_get_readrq(struct pci_dev *dev)
{
u16 ctl;
pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
return 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12);
}
EXPORT_SYMBOL(pcie_get_readrq);
/**
* pcie_set_readrq - set PCI Express maximum memory read request
* @dev: PCI device to query
* @rq: maximum memory read count in bytes
* valid values are 128, 256, 512, 1024, 2048, 4096
*
* If possible sets maximum memory read request in bytes
*/
int pcie_set_readrq(struct pci_dev *dev, int rq)
{
u16 v;
if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
return -EINVAL;
/*
* If using the "performance" PCIe config, we clamp the
* read rq size to the max packet size to prevent the
* host bridge generating requests larger than we can
* cope with
*/
if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
int mps = pcie_get_mps(dev);
if (mps < rq)
rq = mps;
}
v = (ffs(rq) - 8) << 12;
return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
PCI_EXP_DEVCTL_READRQ, v);
}
EXPORT_SYMBOL(pcie_set_readrq);
/**
* pcie_get_mps - get PCI Express maximum payload size
* @dev: PCI device to query
*
* Returns maximum payload size in bytes
*/
int pcie_get_mps(struct pci_dev *dev)
{
u16 ctl;
pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
return 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5);
}
EXPORT_SYMBOL(pcie_get_mps);
/**
* pcie_set_mps - set PCI Express maximum payload size
* @dev: PCI device to query
* @mps: maximum payload size in bytes
* valid values are 128, 256, 512, 1024, 2048, 4096
*
* If possible sets maximum payload size
*/
int pcie_set_mps(struct pci_dev *dev, int mps)
{
u16 v;
if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
return -EINVAL;
v = ffs(mps) - 8;
if (v > dev->pcie_mpss)
return -EINVAL;
v <<= 5;
return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
PCI_EXP_DEVCTL_PAYLOAD, v);
}
EXPORT_SYMBOL(pcie_set_mps);
/**
* pcie_get_minimum_link - determine minimum link settings of a PCI device
* @dev: PCI device to query
* @speed: storage for minimum speed
* @width: storage for minimum width
*
* This function will walk up the PCI device chain and determine the minimum
* link width and speed of the device.
*/
int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed,
enum pcie_link_width *width)
{
int ret;
*speed = PCI_SPEED_UNKNOWN;
*width = PCIE_LNK_WIDTH_UNKNOWN;
while (dev) {
u16 lnksta;
enum pci_bus_speed next_speed;
enum pcie_link_width next_width;
ret = pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
if (ret)
return ret;
next_speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS];
next_width = (lnksta & PCI_EXP_LNKSTA_NLW) >>
PCI_EXP_LNKSTA_NLW_SHIFT;
if (next_speed < *speed)
*speed = next_speed;
if (next_width < *width)
*width = next_width;
dev = dev->bus->self;
}
return 0;
}
EXPORT_SYMBOL(pcie_get_minimum_link);
/**
* pci_select_bars - Make BAR mask from the type of resource
* @dev: the PCI device for which BAR mask is made
* @flags: resource type mask to be selected
*
* This helper routine makes bar mask from the type of resource.
*/
int pci_select_bars(struct pci_dev *dev, unsigned long flags)
{
int i, bars = 0;
for (i = 0; i < PCI_NUM_RESOURCES; i++)
if (pci_resource_flags(dev, i) & flags)
bars |= (1 << i);
return bars;
}
EXPORT_SYMBOL(pci_select_bars);
/* Some architectures require additional programming to enable VGA */
static arch_set_vga_state_t arch_set_vga_state;
void __init pci_register_set_vga_state(arch_set_vga_state_t func)
{
arch_set_vga_state = func; /* NULL disables */
}
static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode,
unsigned int command_bits, u32 flags)
{
if (arch_set_vga_state)
return arch_set_vga_state(dev, decode, command_bits,
flags);
return 0;
}
/**
* pci_set_vga_state - set VGA decode state on device and parents if requested
* @dev: the PCI device
* @decode: true = enable decoding, false = disable decoding
* @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY
* @flags: traverse ancestors and change bridges
* CHANGE_BRIDGE_ONLY / CHANGE_BRIDGE
*/
int pci_set_vga_state(struct pci_dev *dev, bool decode,
unsigned int command_bits, u32 flags)
{
struct pci_bus *bus;
struct pci_dev *bridge;
u16 cmd;
int rc;
WARN_ON((flags & PCI_VGA_STATE_CHANGE_DECODES) && (command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY)));
/* ARCH specific VGA enables */
rc = pci_set_vga_state_arch(dev, decode, command_bits, flags);
if (rc)
return rc;
if (flags & PCI_VGA_STATE_CHANGE_DECODES) {
pci_read_config_word(dev, PCI_COMMAND, &cmd);
if (decode == true)
cmd |= command_bits;
else
cmd &= ~command_bits;
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
if (!(flags & PCI_VGA_STATE_CHANGE_BRIDGE))
return 0;
bus = dev->bus;
while (bus) {
bridge = bus->self;
if (bridge) {
pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
&cmd);
if (decode == true)
cmd |= PCI_BRIDGE_CTL_VGA;
else
cmd &= ~PCI_BRIDGE_CTL_VGA;
pci_write_config_word(bridge, PCI_BRIDGE_CONTROL,
cmd);
}
bus = bus->parent;
}
return 0;
}
/**
* pci_add_dma_alias - Add a DMA devfn alias for a device
* @dev: the PCI device for which alias is added
* @devfn: alias slot and function
*
* This helper encodes 8-bit devfn as bit number in dma_alias_mask.
* It should be called early, preferably as PCI fixup header quirk.
*/
void pci_add_dma_alias(struct pci_dev *dev, u8 devfn)
{
if (!dev->dma_alias_mask)
dev->dma_alias_mask = kcalloc(BITS_TO_LONGS(U8_MAX),
sizeof(long), GFP_KERNEL);
if (!dev->dma_alias_mask) {
pci_warn(dev, "Unable to allocate DMA alias mask\n");
return;
}
set_bit(devfn, dev->dma_alias_mask);
pci_info(dev, "Enabling fixed DMA alias to %02x.%d\n",
PCI_SLOT(devfn), PCI_FUNC(devfn));
}
bool pci_devs_are_dma_aliases(struct pci_dev *dev1, struct pci_dev *dev2)
{
return (dev1->dma_alias_mask &&
test_bit(dev2->devfn, dev1->dma_alias_mask)) ||
(dev2->dma_alias_mask &&
test_bit(dev1->devfn, dev2->dma_alias_mask));
}
bool pci_device_is_present(struct pci_dev *pdev)
{
u32 v;
if (pci_dev_is_disconnected(pdev))
return false;
return pci_bus_read_dev_vendor_id(pdev->bus, pdev->devfn, &v, 0);
}
EXPORT_SYMBOL_GPL(pci_device_is_present);
void pci_ignore_hotplug(struct pci_dev *dev)
{
struct pci_dev *bridge = dev->bus->self;
dev->ignore_hotplug = 1;
/* Propagate the "ignore hotplug" setting to the parent bridge. */
if (bridge)
bridge->ignore_hotplug = 1;
}
EXPORT_SYMBOL_GPL(pci_ignore_hotplug);
resource_size_t __weak pcibios_default_alignment(void)
{
return 0;
}
#define RESOURCE_ALIGNMENT_PARAM_SIZE COMMAND_LINE_SIZE
static char resource_alignment_param[RESOURCE_ALIGNMENT_PARAM_SIZE] = {0};
static DEFINE_SPINLOCK(resource_alignment_lock);
/**
* pci_specified_resource_alignment - get resource alignment specified by user.
* @dev: the PCI device to get
* @resize: whether or not to change resources' size when reassigning alignment
*
* RETURNS: Resource alignment if it is specified.
* Zero if it is not specified.
*/
static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev,
bool *resize)
{
int seg, bus, slot, func, align_order, count;
unsigned short vendor, device, subsystem_vendor, subsystem_device;
resource_size_t align = pcibios_default_alignment();
char *p;
spin_lock(&resource_alignment_lock);
p = resource_alignment_param;
if (!*p && !align)
goto out;
if (pci_has_flag(PCI_PROBE_ONLY)) {
align = 0;
pr_info_once("PCI: Ignoring requested alignments (PCI_PROBE_ONLY)\n");
goto out;
}
while (*p) {
count = 0;
if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
p[count] == '@') {
p += count + 1;
} else {
align_order = -1;
}
if (strncmp(p, "pci:", 4) == 0) {
/* PCI vendor/device (subvendor/subdevice) ids are specified */
p += 4;
if (sscanf(p, "%hx:%hx:%hx:%hx%n",
&vendor, &device, &subsystem_vendor, &subsystem_device, &count) != 4) {
if (sscanf(p, "%hx:%hx%n", &vendor, &device, &count) != 2) {
printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: pci:%s\n",
p);
break;
}
subsystem_vendor = subsystem_device = 0;
}
p += count;
if ((!vendor || (vendor == dev->vendor)) &&
(!device || (device == dev->device)) &&
(!subsystem_vendor || (subsystem_vendor == dev->subsystem_vendor)) &&
(!subsystem_device || (subsystem_device == dev->subsystem_device))) {
*resize = true;
if (align_order == -1)
align = PAGE_SIZE;
else
align = 1 << align_order;
/* Found */
break;
}
}
else {
if (sscanf(p, "%x:%x:%x.%x%n",
&seg, &bus, &slot, &func, &count) != 4) {
seg = 0;
if (sscanf(p, "%x:%x.%x%n",
&bus, &slot, &func, &count) != 3) {
/* Invalid format */
printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: %s\n",
p);
break;
}
}
p += count;
if (seg == pci_domain_nr(dev->bus) &&
bus == dev->bus->number &&
slot == PCI_SLOT(dev->devfn) &&
func == PCI_FUNC(dev->devfn)) {
*resize = true;
if (align_order == -1)
align = PAGE_SIZE;
else
align = 1 << align_order;
/* Found */
break;
}
}
if (*p != ';' && *p != ',') {
/* End of param or invalid format */
break;
}
p++;
}
out:
spin_unlock(&resource_alignment_lock);
return align;
}
static void pci_request_resource_alignment(struct pci_dev *dev, int bar,
resource_size_t align, bool resize)
{
struct resource *r = &dev->resource[bar];
resource_size_t size;
if (!(r->flags & IORESOURCE_MEM))
return;
if (r->flags & IORESOURCE_PCI_FIXED) {
pci_info(dev, "BAR%d %pR: ignoring requested alignment %#llx\n",
bar, r, (unsigned long long)align);
return;
}
size = resource_size(r);
if (size >= align)
return;
/*
* Increase the alignment of the resource. There are two ways we
* can do this:
*
* 1) Increase the size of the resource. BARs are aligned on their
* size, so when we reallocate space for this resource, we'll
* allocate it with the larger alignment. This also prevents
* assignment of any other BARs inside the alignment region, so
* if we're requesting page alignment, this means no other BARs
* will share the page.
*
* The disadvantage is that this makes the resource larger than
* the hardware BAR, which may break drivers that compute things
* based on the resource size, e.g., to find registers at a
* fixed offset before the end of the BAR.
*
* 2) Retain the resource size, but use IORESOURCE_STARTALIGN and
* set r->start to the desired alignment. By itself this
* doesn't prevent other BARs being put inside the alignment
* region, but if we realign *every* resource of every device in
* the system, none of them will share an alignment region.
*
* When the user has requested alignment for only some devices via
* the "pci=resource_alignment" argument, "resize" is true and we
* use the first method. Otherwise we assume we're aligning all
* devices and we use the second.
*/
pci_info(dev, "BAR%d %pR: requesting alignment to %#llx\n",
bar, r, (unsigned long long)align);
if (resize) {
r->start = 0;
r->end = align - 1;
} else {
r->flags &= ~IORESOURCE_SIZEALIGN;
r->flags |= IORESOURCE_STARTALIGN;
r->start = align;
r->end = r->start + size - 1;
}
r->flags |= IORESOURCE_UNSET;
}
/*
* This function disables memory decoding and releases memory resources
* of the device specified by kernel's boot parameter 'pci=resource_alignment='.
* It also rounds up size to specified alignment.
* Later on, the kernel will assign page-aligned memory resource back
* to the device.
*/
void pci_reassigndev_resource_alignment(struct pci_dev *dev)
{
int i;
struct resource *r;
resource_size_t align;
u16 command;
bool resize = false;
/*
* VF BARs are read-only zero according to SR-IOV spec r1.1, sec
* 3.4.1.11. Their resources are allocated from the space
* described by the VF BARx register in the PF's SR-IOV capability.
* We can't influence their alignment here.
*/
if (dev->is_virtfn)
return;
/* check if specified PCI is target device to reassign */
align = pci_specified_resource_alignment(dev, &resize);
if (!align)
return;
if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL &&
(dev->class >> 8) == PCI_CLASS_BRIDGE_HOST) {
pci_warn(dev, "Can't reassign resources to host bridge\n");
return;
}
pci_info(dev, "Disabling memory decoding and releasing memory resources\n");
pci_read_config_word(dev, PCI_COMMAND, &command);
command &= ~PCI_COMMAND_MEMORY;
pci_write_config_word(dev, PCI_COMMAND, command);
for (i = 0; i <= PCI_ROM_RESOURCE; i++)
pci_request_resource_alignment(dev, i, align, resize);
/*
* Need to disable bridge's resource window,
* to enable the kernel to reassign new resource
* window later on.
*/
if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE &&
(dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) {
r = &dev->resource[i];
if (!(r->flags & IORESOURCE_MEM))
continue;
r->flags |= IORESOURCE_UNSET;
r->end = resource_size(r) - 1;
r->start = 0;
}
pci_disable_bridge_window(dev);
}
}
static ssize_t pci_set_resource_alignment_param(const char *buf, size_t count)
{
if (count > RESOURCE_ALIGNMENT_PARAM_SIZE - 1)
count = RESOURCE_ALIGNMENT_PARAM_SIZE - 1;
spin_lock(&resource_alignment_lock);
strncpy(resource_alignment_param, buf, count);
resource_alignment_param[count] = '\0';
spin_unlock(&resource_alignment_lock);
return count;
}
static ssize_t pci_get_resource_alignment_param(char *buf, size_t size)
{
size_t count;
spin_lock(&resource_alignment_lock);
count = snprintf(buf, size, "%s", resource_alignment_param);
spin_unlock(&resource_alignment_lock);
return count;
}
static ssize_t pci_resource_alignment_show(struct bus_type *bus, char *buf)
{
return pci_get_resource_alignment_param(buf, PAGE_SIZE);
}
static ssize_t pci_resource_alignment_store(struct bus_type *bus,
const char *buf, size_t count)
{
return pci_set_resource_alignment_param(buf, count);
}
static BUS_ATTR(resource_alignment, 0644, pci_resource_alignment_show,
pci_resource_alignment_store);
static int __init pci_resource_alignment_sysfs_init(void)
{
return bus_create_file(&pci_bus_type,
&bus_attr_resource_alignment);
}
late_initcall(pci_resource_alignment_sysfs_init);
static void pci_no_domains(void)
{
#ifdef CONFIG_PCI_DOMAINS
pci_domains_supported = 0;
#endif
}
#ifdef CONFIG_PCI_DOMAINS
static atomic_t __domain_nr = ATOMIC_INIT(-1);
int pci_get_new_domain_nr(void)
{
return atomic_inc_return(&__domain_nr);
}
#ifdef CONFIG_PCI_DOMAINS_GENERIC
static int of_pci_bus_find_domain_nr(struct device *parent)
{
static int use_dt_domains = -1;
int domain = -1;
if (parent)
domain = of_get_pci_domain_nr(parent->of_node);
/*
* Check DT domain and use_dt_domains values.
*
* If DT domain property is valid (domain >= 0) and
* use_dt_domains != 0, the DT assignment is valid since this means
* we have not previously allocated a domain number by using
* pci_get_new_domain_nr(); we should also update use_dt_domains to
* 1, to indicate that we have just assigned a domain number from
* DT.
*
* If DT domain property value is not valid (ie domain < 0), and we
* have not previously assigned a domain number from DT
* (use_dt_domains != 1) we should assign a domain number by
* using the:
*
* pci_get_new_domain_nr()
*
* API and update the use_dt_domains value to keep track of method we
* are using to assign domain numbers (use_dt_domains = 0).
*
* All other combinations imply we have a platform that is trying
* to mix domain numbers obtained from DT and pci_get_new_domain_nr(),
* which is a recipe for domain mishandling and it is prevented by
* invalidating the domain value (domain = -1) and printing a
* corresponding error.
*/
if (domain >= 0 && use_dt_domains) {
use_dt_domains = 1;
} else if (domain < 0 && use_dt_domains != 1) {
use_dt_domains = 0;
domain = pci_get_new_domain_nr();
} else {
dev_err(parent, "Node %pOF has inconsistent \"linux,pci-domain\" property in DT\n",
parent->of_node);
domain = -1;
}
return domain;
}
int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent)
{
return acpi_disabled ? of_pci_bus_find_domain_nr(parent) :
acpi_pci_bus_find_domain_nr(bus);
}
#endif
#endif
/**
* pci_ext_cfg_avail - can we access extended PCI config space?
*
* Returns 1 if we can access PCI extended config space (offsets
* greater than 0xff). This is the default implementation. Architecture
* implementations can override this.
*/
int __weak pci_ext_cfg_avail(void)
{
return 1;
}
void __weak pci_fixup_cardbus(struct pci_bus *bus)
{
}
EXPORT_SYMBOL(pci_fixup_cardbus);
static int __init pci_setup(char *str)
{
while (str) {
char *k = strchr(str, ',');
if (k)
*k++ = 0;
if (*str && (str = pcibios_setup(str)) && *str) {
if (!strcmp(str, "nomsi")) {
pci_no_msi();
} else if (!strcmp(str, "noaer")) {
pci_no_aer();
} else if (!strncmp(str, "realloc=", 8)) {
pci_realloc_get_opt(str + 8);
} else if (!strncmp(str, "realloc", 7)) {
pci_realloc_get_opt("on");
} else if (!strcmp(str, "nodomains")) {
pci_no_domains();
} else if (!strncmp(str, "noari", 5)) {
pcie_ari_disabled = true;
} else if (!strncmp(str, "cbiosize=", 9)) {
pci_cardbus_io_size = memparse(str + 9, &str);
} else if (!strncmp(str, "cbmemsize=", 10)) {
pci_cardbus_mem_size = memparse(str + 10, &str);
} else if (!strncmp(str, "resource_alignment=", 19)) {
pci_set_resource_alignment_param(str + 19,
strlen(str + 19));
} else if (!strncmp(str, "ecrc=", 5)) {
pcie_ecrc_get_policy(str + 5);
} else if (!strncmp(str, "hpiosize=", 9)) {
pci_hotplug_io_size = memparse(str + 9, &str);
} else if (!strncmp(str, "hpmemsize=", 10)) {
pci_hotplug_mem_size = memparse(str + 10, &str);
} else if (!strncmp(str, "hpbussize=", 10)) {
pci_hotplug_bus_size =
simple_strtoul(str + 10, &str, 0);
if (pci_hotplug_bus_size > 0xff)
pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE;
} else if (!strncmp(str, "pcie_bus_tune_off", 17)) {
pcie_bus_config = PCIE_BUS_TUNE_OFF;
} else if (!strncmp(str, "pcie_bus_safe", 13)) {
pcie_bus_config = PCIE_BUS_SAFE;
} else if (!strncmp(str, "pcie_bus_perf", 13)) {
pcie_bus_config = PCIE_BUS_PERFORMANCE;
} else if (!strncmp(str, "pcie_bus_peer2peer", 18)) {
pcie_bus_config = PCIE_BUS_PEER2PEER;
} else if (!strncmp(str, "pcie_scan_all", 13)) {
pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
} else {
printk(KERN_ERR "PCI: Unknown option `%s'\n",
str);
}
}
str = k;
}
return 0;
}
early_param("pci", pci_setup);
Reference in New Issue View Git Blame Copy Permalink