linux/arch/powerpc/kernel/pci_32.c
Sam Bobroff 3f068aae7a powerpc/64: Adjust order in pcibios_init()
The pcibios_init() function for PowerPC 64 currently calls
pci_bus_add_devices() before pcibios_resource_survey(). This means
that at boot time, when the pcibios_bus_add_device() hooks are called
by pci_bus_add_devices(), device resources have not been allocated and
they are unable to perform EEH setup, so a separate pass is needed.

This patch adjusts that order so that it will become possible to
consolidate the EEH setup work into a single location.

The only functional change is to execute pcibios_resource_survey()
(excepting ppc_md.pcibios_fixup(), see below) before
pci_bus_add_devices() instead of after it.

Because pcibios_scan_phb() and pci_bus_add_devices() are called
together in a loop, this must be broken into one loop for each call.
Then the call to pcibios_resource_survey() is moved up in between
them. This changes the ordering but because pcibios_resource_survey()
also calls ppc_md.pcibios_fixup(), that call is extracted out into
pcibios_init() to where pcibios_resource_survey() was, so that it is
not moved.

The only other caller of pcibios_resource_survey() is the PowerPC 32
version of pcibios_init(), and therefore, that is modified to call
ppc_md.pcibios_fixup() right after pcibios_resource_survey() so that
there is no functional change there at all.

The re-arrangement will cause very few side-effects because at this
stage in the boot, pci_bus_add_devices() does very little:
- pci_create_sysfs_dev_files() does nothing (no sysfs yet)
- pci_proc_attach_device() does nothing (no proc yet)
- device_attach() does nothing (no drivers yet)
This leaves only the pci_final_fixup calls, D3 support, and marking
the device as added. Of those, only the pci_final_fixup calls have the
potential to be affected by resource allocation.

The only pci_final_fixup handlers that touch resources seem to be one
for x86 (pci_amd_enable_64bit_bar()), and a PowerPC 32 platform driver
(quirk_final_uli1575()), neither of which use this pcibios_init()
function. Even if they did, it would almost certainly be a bug, under
the current ordering, to rely on or make changes to resources before
they were allocated.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4506b0489eabd0921a3587d90bd44c7683f3472d.1565930772.git.sbobroff@linux.ibm.com
2019-08-22 23:11:48 +10:00

321 lines
7.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Common pmac/prep/chrp pci routines. -- Cort
*/
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/capability.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/memblock.h>
#include <linux/syscalls.h>
#include <linux/irq.h>
#include <linux/list.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <asm/processor.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/sections.h>
#include <asm/pci-bridge.h>
#include <asm/ppc-pci.h>
#include <asm/byteorder.h>
#include <linux/uaccess.h>
#include <asm/machdep.h>
#undef DEBUG
unsigned long isa_io_base = 0;
unsigned long pci_dram_offset = 0;
int pcibios_assign_bus_offset = 1;
EXPORT_SYMBOL(isa_io_base);
EXPORT_SYMBOL(pci_dram_offset);
void pcibios_make_OF_bus_map(void);
static void fixup_cpc710_pci64(struct pci_dev* dev);
static u8* pci_to_OF_bus_map;
/* By default, we don't re-assign bus numbers. We do this only on
* some pmacs
*/
static int pci_assign_all_buses;
static int pci_bus_count;
/* This will remain NULL for now, until isa-bridge.c is made common
* to both 32-bit and 64-bit.
*/
struct pci_dev *isa_bridge_pcidev;
EXPORT_SYMBOL_GPL(isa_bridge_pcidev);
static void
fixup_cpc710_pci64(struct pci_dev* dev)
{
/* Hide the PCI64 BARs from the kernel as their content doesn't
* fit well in the resource management
*/
dev->resource[0].start = dev->resource[0].end = 0;
dev->resource[0].flags = 0;
dev->resource[1].start = dev->resource[1].end = 0;
dev->resource[1].flags = 0;
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_CPC710_PCI64, fixup_cpc710_pci64);
/*
* Functions below are used on OpenFirmware machines.
*/
static void
make_one_node_map(struct device_node* node, u8 pci_bus)
{
const int *bus_range;
int len;
if (pci_bus >= pci_bus_count)
return;
bus_range = of_get_property(node, "bus-range", &len);
if (bus_range == NULL || len < 2 * sizeof(int)) {
printk(KERN_WARNING "Can't get bus-range for %pOF, "
"assuming it starts at 0\n", node);
pci_to_OF_bus_map[pci_bus] = 0;
} else
pci_to_OF_bus_map[pci_bus] = bus_range[0];
for_each_child_of_node(node, node) {
struct pci_dev* dev;
const unsigned int *class_code, *reg;
class_code = of_get_property(node, "class-code", NULL);
if (!class_code || ((*class_code >> 8) != PCI_CLASS_BRIDGE_PCI &&
(*class_code >> 8) != PCI_CLASS_BRIDGE_CARDBUS))
continue;
reg = of_get_property(node, "reg", NULL);
if (!reg)
continue;
dev = pci_get_domain_bus_and_slot(0, pci_bus,
((reg[0] >> 8) & 0xff));
if (!dev || !dev->subordinate) {
pci_dev_put(dev);
continue;
}
make_one_node_map(node, dev->subordinate->number);
pci_dev_put(dev);
}
}
void
pcibios_make_OF_bus_map(void)
{
int i;
struct pci_controller *hose, *tmp;
struct property *map_prop;
struct device_node *dn;
pci_to_OF_bus_map = kmalloc(pci_bus_count, GFP_KERNEL);
if (!pci_to_OF_bus_map) {
printk(KERN_ERR "Can't allocate OF bus map !\n");
return;
}
/* We fill the bus map with invalid values, that helps
* debugging.
*/
for (i=0; i<pci_bus_count; i++)
pci_to_OF_bus_map[i] = 0xff;
/* For each hose, we begin searching bridges */
list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
struct device_node* node = hose->dn;
if (!node)
continue;
make_one_node_map(node, hose->first_busno);
}
dn = of_find_node_by_path("/");
map_prop = of_find_property(dn, "pci-OF-bus-map", NULL);
if (map_prop) {
BUG_ON(pci_bus_count > map_prop->length);
memcpy(map_prop->value, pci_to_OF_bus_map, pci_bus_count);
}
of_node_put(dn);
#ifdef DEBUG
printk("PCI->OF bus map:\n");
for (i=0; i<pci_bus_count; i++) {
if (pci_to_OF_bus_map[i] == 0xff)
continue;
printk("%d -> %d\n", i, pci_to_OF_bus_map[i]);
}
#endif
}
/*
* Returns the PCI device matching a given OF node
*/
int pci_device_from_OF_node(struct device_node *node, u8 *bus, u8 *devfn)
{
struct pci_dev *dev = NULL;
const __be32 *reg;
int size;
/* Check if it might have a chance to be a PCI device */
if (!pci_find_hose_for_OF_device(node))
return -ENODEV;
reg = of_get_property(node, "reg", &size);
if (!reg || size < 5 * sizeof(u32))
return -ENODEV;
*bus = (be32_to_cpup(&reg[0]) >> 16) & 0xff;
*devfn = (be32_to_cpup(&reg[0]) >> 8) & 0xff;
/* Ok, here we need some tweak. If we have already renumbered
* all busses, we can't rely on the OF bus number any more.
* the pci_to_OF_bus_map is not enough as several PCI busses
* may match the same OF bus number.
*/
if (!pci_to_OF_bus_map)
return 0;
for_each_pci_dev(dev)
if (pci_to_OF_bus_map[dev->bus->number] == *bus &&
dev->devfn == *devfn) {
*bus = dev->bus->number;
pci_dev_put(dev);
return 0;
}
return -ENODEV;
}
EXPORT_SYMBOL(pci_device_from_OF_node);
/* We create the "pci-OF-bus-map" property now so it appears in the
* /proc device tree
*/
void __init
pci_create_OF_bus_map(void)
{
struct property* of_prop;
struct device_node *dn;
of_prop = memblock_alloc(sizeof(struct property) + 256,
SMP_CACHE_BYTES);
if (!of_prop)
panic("%s: Failed to allocate %zu bytes\n", __func__,
sizeof(struct property) + 256);
dn = of_find_node_by_path("/");
if (dn) {
memset(of_prop, -1, sizeof(struct property) + 256);
of_prop->name = "pci-OF-bus-map";
of_prop->length = 256;
of_prop->value = &of_prop[1];
of_add_property(dn, of_prop);
of_node_put(dn);
}
}
void pcibios_setup_phb_io_space(struct pci_controller *hose)
{
unsigned long io_offset;
struct resource *res = &hose->io_resource;
/* Fixup IO space offset */
io_offset = pcibios_io_space_offset(hose);
res->start += io_offset;
res->end += io_offset;
}
static int __init pcibios_init(void)
{
struct pci_controller *hose, *tmp;
int next_busno = 0;
printk(KERN_INFO "PCI: Probing PCI hardware\n");
if (pci_has_flag(PCI_REASSIGN_ALL_BUS))
pci_assign_all_buses = 1;
/* Scan all of the recorded PCI controllers. */
list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
if (pci_assign_all_buses)
hose->first_busno = next_busno;
hose->last_busno = 0xff;
pcibios_scan_phb(hose);
pci_bus_add_devices(hose->bus);
if (pci_assign_all_buses || next_busno <= hose->last_busno)
next_busno = hose->last_busno + pcibios_assign_bus_offset;
}
pci_bus_count = next_busno;
/* OpenFirmware based machines need a map of OF bus
* numbers vs. kernel bus numbers since we may have to
* remap them.
*/
if (pci_assign_all_buses)
pcibios_make_OF_bus_map();
/* Call common code to handle resource allocation */
pcibios_resource_survey();
/* Call machine dependent fixup */
if (ppc_md.pcibios_fixup)
ppc_md.pcibios_fixup();
/* Call machine dependent post-init code */
if (ppc_md.pcibios_after_init)
ppc_md.pcibios_after_init();
return 0;
}
subsys_initcall(pcibios_init);
static struct pci_controller*
pci_bus_to_hose(int bus)
{
struct pci_controller *hose, *tmp;
list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
if (bus >= hose->first_busno && bus <= hose->last_busno)
return hose;
return NULL;
}
/* Provide information on locations of various I/O regions in physical
* memory. Do this on a per-card basis so that we choose the right
* root bridge.
* Note that the returned IO or memory base is a physical address
*/
SYSCALL_DEFINE3(pciconfig_iobase, long, which,
unsigned long, bus, unsigned long, devfn)
{
struct pci_controller* hose;
long result = -EOPNOTSUPP;
hose = pci_bus_to_hose(bus);
if (!hose)
return -ENODEV;
switch (which) {
case IOBASE_BRIDGE_NUMBER:
return (long)hose->first_busno;
case IOBASE_MEMORY:
return (long)hose->mem_offset[0];
case IOBASE_IO:
return (long)hose->io_base_phys;
case IOBASE_ISA_IO:
return (long)isa_io_base;
case IOBASE_ISA_MEM:
return (long)isa_mem_base;
}
return result;
}