linux/drivers/pci/host/pci-thunder-ecam.c
Brian Norris a5f40e8098 PCI: Don't allow unbinding host controllers that aren't prepared
Many PCI host controller drivers aren't prepared to have their devices
unbound from them forcefully (e.g., through /sys/.../<driver>/unbind), as
they don't provide any driver .remove callback, where they'd detach the
root bus, release resources, etc. Keeping the driver built in (i.e., not a
loadable module) is not enough; and providing no .remove callback just
means we don't do any teardown.

To rule out the possibility of unbinding a device via sysfs, we need to set
the ".suppress_bind_attrs" field.

I found the suspect drivers via the following search:

  git grep -l platform_driver $(git grep -L -e '\.remove' -e suppress_bind_attrs drivers/pci/)

Then I inspected them to ensure that
(a) they set up a PCI bus in their probe() and
(b) they don't have a remove() callback for undoing the setup

Suggested-by: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-04-28 10:38:00 -05:00

384 lines
9.6 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2015, 2016 Cavium, Inc.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/of_pci.h>
#include <linux/of.h>
#include <linux/pci-ecam.h>
#include <linux/platform_device.h>
#if defined(CONFIG_PCI_HOST_THUNDER_ECAM) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS))
static void set_val(u32 v, int where, int size, u32 *val)
{
int shift = (where & 3) * 8;
pr_debug("set_val %04x: %08x\n", (unsigned)(where & ~3), v);
v >>= shift;
if (size == 1)
v &= 0xff;
else if (size == 2)
v &= 0xffff;
*val = v;
}
static int handle_ea_bar(u32 e0, int bar, struct pci_bus *bus,
unsigned int devfn, int where, int size, u32 *val)
{
void __iomem *addr;
u32 v;
/* Entries are 16-byte aligned; bits[2,3] select word in entry */
int where_a = where & 0xc;
if (where_a == 0) {
set_val(e0, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
if (where_a == 0x4) {
addr = bus->ops->map_bus(bus, devfn, bar); /* BAR 0 */
if (!addr) {
*val = ~0;
return PCIBIOS_DEVICE_NOT_FOUND;
}
v = readl(addr);
v &= ~0xf;
v |= 2; /* EA entry-1. Base-L */
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
if (where_a == 0x8) {
u32 barl_orig;
u32 barl_rb;
addr = bus->ops->map_bus(bus, devfn, bar); /* BAR 0 */
if (!addr) {
*val = ~0;
return PCIBIOS_DEVICE_NOT_FOUND;
}
barl_orig = readl(addr + 0);
writel(0xffffffff, addr + 0);
barl_rb = readl(addr + 0);
writel(barl_orig, addr + 0);
/* zeros in unsettable bits */
v = ~barl_rb & ~3;
v |= 0xc; /* EA entry-2. Offset-L */
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
if (where_a == 0xc) {
addr = bus->ops->map_bus(bus, devfn, bar + 4); /* BAR 1 */
if (!addr) {
*val = ~0;
return PCIBIOS_DEVICE_NOT_FOUND;
}
v = readl(addr); /* EA entry-3. Base-H */
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
return PCIBIOS_DEVICE_NOT_FOUND;
}
static int thunder_ecam_p2_config_read(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
struct pci_config_window *cfg = bus->sysdata;
int where_a = where & ~3;
void __iomem *addr;
u32 node_bits;
u32 v;
/* EA Base[63:32] may be missing some bits ... */
switch (where_a) {
case 0xa8:
case 0xbc:
case 0xd0:
case 0xe4:
break;
default:
return pci_generic_config_read(bus, devfn, where, size, val);
}
addr = bus->ops->map_bus(bus, devfn, where_a);
if (!addr) {
*val = ~0;
return PCIBIOS_DEVICE_NOT_FOUND;
}
v = readl(addr);
/*
* Bit 44 of the 64-bit Base must match the same bit in
* the config space access window. Since we are working with
* the high-order 32 bits, shift everything down by 32 bits.
*/
node_bits = (cfg->res.start >> 32) & (1 << 12);
v |= node_bits;
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
static int thunder_ecam_config_read(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
u32 v;
u32 vendor_device;
u32 class_rev;
void __iomem *addr;
int cfg_type;
int where_a = where & ~3;
addr = bus->ops->map_bus(bus, devfn, 0xc);
if (!addr) {
*val = ~0;
return PCIBIOS_DEVICE_NOT_FOUND;
}
v = readl(addr);
/* Check for non type-00 header */
cfg_type = (v >> 16) & 0x7f;
addr = bus->ops->map_bus(bus, devfn, 8);
if (!addr) {
*val = ~0;
return PCIBIOS_DEVICE_NOT_FOUND;
}
class_rev = readl(addr);
if (class_rev == 0xffffffff)
goto no_emulation;
if ((class_rev & 0xff) >= 8) {
/* Pass-2 handling */
if (cfg_type)
goto no_emulation;
return thunder_ecam_p2_config_read(bus, devfn, where,
size, val);
}
/*
* All BARs have fixed addresses specified by the EA
* capability; they must return zero on read.
*/
if (cfg_type == 0 &&
((where >= 0x10 && where < 0x2c) ||
(where >= 0x1a4 && where < 0x1bc))) {
/* BAR or SR-IOV BAR */
*val = 0;
return PCIBIOS_SUCCESSFUL;
}
addr = bus->ops->map_bus(bus, devfn, 0);
if (!addr) {
*val = ~0;
return PCIBIOS_DEVICE_NOT_FOUND;
}
vendor_device = readl(addr);
if (vendor_device == 0xffffffff)
goto no_emulation;
pr_debug("%04x:%04x - Fix pass#: %08x, where: %03x, devfn: %03x\n",
vendor_device & 0xffff, vendor_device >> 16, class_rev,
(unsigned) where, devfn);
/* Check for non type-00 header */
if (cfg_type == 0) {
bool has_msix;
bool is_nic = (vendor_device == 0xa01e177d);
bool is_tns = (vendor_device == 0xa01f177d);
addr = bus->ops->map_bus(bus, devfn, 0x70);
if (!addr) {
*val = ~0;
return PCIBIOS_DEVICE_NOT_FOUND;
}
/* E_CAP */
v = readl(addr);
has_msix = (v & 0xff00) != 0;
if (!has_msix && where_a == 0x70) {
v |= 0xbc00; /* next capability is EA at 0xbc */
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
if (where_a == 0xb0) {
addr = bus->ops->map_bus(bus, devfn, where_a);
if (!addr) {
*val = ~0;
return PCIBIOS_DEVICE_NOT_FOUND;
}
v = readl(addr);
if (v & 0xff00)
pr_err("Bad MSIX cap header: %08x\n", v);
v |= 0xbc00; /* next capability is EA at 0xbc */
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
if (where_a == 0xbc) {
if (is_nic)
v = 0x40014; /* EA last in chain, 4 entries */
else if (is_tns)
v = 0x30014; /* EA last in chain, 3 entries */
else if (has_msix)
v = 0x20014; /* EA last in chain, 2 entries */
else
v = 0x10014; /* EA last in chain, 1 entry */
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
if (where_a >= 0xc0 && where_a < 0xd0)
/* EA entry-0. PP=0, BAR0 Size:3 */
return handle_ea_bar(0x80ff0003,
0x10, bus, devfn, where,
size, val);
if (where_a >= 0xd0 && where_a < 0xe0 && has_msix)
/* EA entry-1. PP=0, BAR4 Size:3 */
return handle_ea_bar(0x80ff0043,
0x20, bus, devfn, where,
size, val);
if (where_a >= 0xe0 && where_a < 0xf0 && is_tns)
/* EA entry-2. PP=0, BAR2, Size:3 */
return handle_ea_bar(0x80ff0023,
0x18, bus, devfn, where,
size, val);
if (where_a >= 0xe0 && where_a < 0xf0 && is_nic)
/* EA entry-2. PP=4, VF_BAR0 (9), Size:3 */
return handle_ea_bar(0x80ff0493,
0x1a4, bus, devfn, where,
size, val);
if (where_a >= 0xf0 && where_a < 0x100 && is_nic)
/* EA entry-3. PP=4, VF_BAR4 (d), Size:3 */
return handle_ea_bar(0x80ff04d3,
0x1b4, bus, devfn, where,
size, val);
} else if (cfg_type == 1) {
bool is_rsl_bridge = devfn == 0x08;
bool is_rad_bridge = devfn == 0xa0;
bool is_zip_bridge = devfn == 0xa8;
bool is_dfa_bridge = devfn == 0xb0;
bool is_nic_bridge = devfn == 0x10;
if (where_a == 0x70) {
addr = bus->ops->map_bus(bus, devfn, where_a);
if (!addr) {
*val = ~0;
return PCIBIOS_DEVICE_NOT_FOUND;
}
v = readl(addr);
if (v & 0xff00)
pr_err("Bad PCIe cap header: %08x\n", v);
v |= 0xbc00; /* next capability is EA at 0xbc */
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
if (where_a == 0xbc) {
if (is_nic_bridge)
v = 0x10014; /* EA last in chain, 1 entry */
else
v = 0x00014; /* EA last in chain, no entries */
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
if (where_a == 0xc0) {
if (is_rsl_bridge || is_nic_bridge)
v = 0x0101; /* subordinate:secondary = 1:1 */
else if (is_rad_bridge)
v = 0x0202; /* subordinate:secondary = 2:2 */
else if (is_zip_bridge)
v = 0x0303; /* subordinate:secondary = 3:3 */
else if (is_dfa_bridge)
v = 0x0404; /* subordinate:secondary = 4:4 */
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
if (where_a == 0xc4 && is_nic_bridge) {
/* Enabled, not-Write, SP=ff, PP=05, BEI=6, ES=4 */
v = 0x80ff0564;
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
if (where_a == 0xc8 && is_nic_bridge) {
v = 0x00000002; /* Base-L 64-bit */
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
if (where_a == 0xcc && is_nic_bridge) {
v = 0xfffffffe; /* MaxOffset-L 64-bit */
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
if (where_a == 0xd0 && is_nic_bridge) {
v = 0x00008430; /* NIC Base-H */
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
if (where_a == 0xd4 && is_nic_bridge) {
v = 0x0000000f; /* MaxOffset-H */
set_val(v, where, size, val);
return PCIBIOS_SUCCESSFUL;
}
}
no_emulation:
return pci_generic_config_read(bus, devfn, where, size, val);
}
static int thunder_ecam_config_write(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val)
{
/*
* All BARs have fixed addresses; ignore BAR writes so they
* don't get corrupted.
*/
if ((where >= 0x10 && where < 0x2c) ||
(where >= 0x1a4 && where < 0x1bc))
/* BAR or SR-IOV BAR */
return PCIBIOS_SUCCESSFUL;
return pci_generic_config_write(bus, devfn, where, size, val);
}
struct pci_ecam_ops pci_thunder_ecam_ops = {
.bus_shift = 20,
.pci_ops = {
.map_bus = pci_ecam_map_bus,
.read = thunder_ecam_config_read,
.write = thunder_ecam_config_write,
}
};
#ifdef CONFIG_PCI_HOST_THUNDER_ECAM
static const struct of_device_id thunder_ecam_of_match[] = {
{ .compatible = "cavium,pci-host-thunder-ecam" },
{ },
};
static int thunder_ecam_probe(struct platform_device *pdev)
{
return pci_host_common_probe(pdev, &pci_thunder_ecam_ops);
}
static struct platform_driver thunder_ecam_driver = {
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = thunder_ecam_of_match,
.suppress_bind_attrs = true,
},
.probe = thunder_ecam_probe,
};
builtin_platform_driver(thunder_ecam_driver);
#endif
#endif