linux/drivers/acpi/pci_irq.c
Rafael J. Wysocki 9e8ce4b96b Revert "x86/PCI: Refine the way to release PCI IRQ resources"
Commit b4b55cda58 (Refine the way to release PCI IRQ resources)
introduced a regression in the PCI IRQ resource management by causing
the IRQ resource of a device, established when pci_enabled_device()
is called on a fully disabled device, to be released when the driver
is unbound from the device, regardless of the enable_cnt.

This leads to the situation that an ill-behaved driver can now make a
device unusable to subsequent drivers by an imbalance in their use of
pci_enable/disable_device().  That is a serious problem for secondary
drivers like vfio-pci, which are innocent of the transgressions of
the previous driver.

Since the solution of this problem is not immediate and requires
further discussion, revert commit b4b55cda58 and the issue it was
supposed to address (a bug related to xen-pciback) will be taken
care of in a different way going forward.

Reported-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-03-20 14:56:19 +01:00

518 lines
14 KiB
C

/*
* pci_irq.c - ACPI PCI Interrupt Routing ($Revision: 11 $)
*
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
* Copyright (C) 2002 Dominik Brodowski <devel@brodo.de>
* (c) Copyright 2008 Hewlett-Packard Development Company, L.P.
* Bjorn Helgaas <bjorn.helgaas@hp.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/dmi.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/pm.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/slab.h>
#define PREFIX "ACPI: "
#define _COMPONENT ACPI_PCI_COMPONENT
ACPI_MODULE_NAME("pci_irq");
struct acpi_prt_entry {
struct list_head list;
struct acpi_pci_id id;
u8 pin;
acpi_handle link;
u32 index; /* GSI, or link _CRS index */
};
static inline char pin_name(int pin)
{
return 'A' + pin - 1;
}
/* --------------------------------------------------------------------------
PCI IRQ Routing Table (PRT) Support
-------------------------------------------------------------------------- */
/* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
static const struct dmi_system_id medion_md9580[] = {
{
.ident = "Medion MD9580-F laptop",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"),
DMI_MATCH(DMI_PRODUCT_NAME, "A555"),
},
},
{ }
};
/* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */
static const struct dmi_system_id dell_optiplex[] = {
{
.ident = "Dell Optiplex GX1",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"),
},
},
{ }
};
/* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */
static const struct dmi_system_id hp_t5710[] = {
{
.ident = "HP t5710",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"),
DMI_MATCH(DMI_BOARD_NAME, "098Ch"),
},
},
{ }
};
struct prt_quirk {
const struct dmi_system_id *system;
unsigned int segment;
unsigned int bus;
unsigned int device;
unsigned char pin;
const char *source; /* according to BIOS */
const char *actual_source;
};
#define PCI_INTX_PIN(c) (c - 'A' + 1)
/*
* These systems have incorrect _PRT entries. The BIOS claims the PCI
* interrupt at the listed segment/bus/device/pin is connected to the first
* link device, but it is actually connected to the second.
*/
static const struct prt_quirk prt_quirks[] = {
{ medion_md9580, 0, 0, 9, PCI_INTX_PIN('A'),
"\\_SB_.PCI0.ISA_.LNKA",
"\\_SB_.PCI0.ISA_.LNKB"},
{ dell_optiplex, 0, 0, 0xd, PCI_INTX_PIN('A'),
"\\_SB_.LNKB",
"\\_SB_.LNKA"},
{ hp_t5710, 0, 0, 1, PCI_INTX_PIN('A'),
"\\_SB_.PCI0.LNK1",
"\\_SB_.PCI0.LNK3"},
};
static void do_prt_fixups(struct acpi_prt_entry *entry,
struct acpi_pci_routing_table *prt)
{
int i;
const struct prt_quirk *quirk;
for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) {
quirk = &prt_quirks[i];
/* All current quirks involve link devices, not GSIs */
if (!prt->source)
continue;
if (dmi_check_system(quirk->system) &&
entry->id.segment == quirk->segment &&
entry->id.bus == quirk->bus &&
entry->id.device == quirk->device &&
entry->pin == quirk->pin &&
!strcmp(prt->source, quirk->source) &&
strlen(prt->source) >= strlen(quirk->actual_source)) {
printk(KERN_WARNING PREFIX "firmware reports "
"%04x:%02x:%02x PCI INT %c connected to %s; "
"changing to %s\n",
entry->id.segment, entry->id.bus,
entry->id.device, pin_name(entry->pin),
prt->source, quirk->actual_source);
strcpy(prt->source, quirk->actual_source);
}
}
}
static int acpi_pci_irq_check_entry(acpi_handle handle, struct pci_dev *dev,
int pin, struct acpi_pci_routing_table *prt,
struct acpi_prt_entry **entry_ptr)
{
int segment = pci_domain_nr(dev->bus);
int bus = dev->bus->number;
int device = PCI_SLOT(dev->devfn);
struct acpi_prt_entry *entry;
if (((prt->address >> 16) & 0xffff) != device ||
prt->pin + 1 != pin)
return -ENODEV;
entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
if (!entry)
return -ENOMEM;
/*
* Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
* 1=INTA, 2=INTB. We use the PCI encoding throughout, so convert
* it here.
*/
entry->id.segment = segment;
entry->id.bus = bus;
entry->id.device = (prt->address >> 16) & 0xFFFF;
entry->pin = prt->pin + 1;
do_prt_fixups(entry, prt);
entry->index = prt->source_index;
/*
* Type 1: Dynamic
* ---------------
* The 'source' field specifies the PCI interrupt link device used to
* configure the IRQ assigned to this slot|dev|pin. The 'source_index'
* indicates which resource descriptor in the resource template (of
* the link device) this interrupt is allocated from.
*
* NOTE: Don't query the Link Device for IRQ information at this time
* because Link Device enumeration may not have occurred yet
* (e.g. exists somewhere 'below' this _PRT entry in the ACPI
* namespace).
*/
if (prt->source[0])
acpi_get_handle(handle, prt->source, &entry->link);
/*
* Type 2: Static
* --------------
* The 'source' field is NULL, and the 'source_index' field specifies
* the IRQ value, which is hardwired to specific interrupt inputs on
* the interrupt controller.
*/
ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
" %04x:%02x:%02x[%c] -> %s[%d]\n",
entry->id.segment, entry->id.bus,
entry->id.device, pin_name(entry->pin),
prt->source, entry->index));
*entry_ptr = entry;
return 0;
}
static int acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
int pin, struct acpi_prt_entry **entry_ptr)
{
acpi_status status;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
struct acpi_pci_routing_table *entry;
acpi_handle handle = NULL;
if (dev->bus->bridge)
handle = ACPI_HANDLE(dev->bus->bridge);
if (!handle)
return -ENODEV;
/* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
status = acpi_get_irq_routing_table(handle, &buffer);
if (ACPI_FAILURE(status)) {
kfree(buffer.pointer);
return -ENODEV;
}
entry = buffer.pointer;
while (entry && (entry->length > 0)) {
if (!acpi_pci_irq_check_entry(handle, dev, pin,
entry, entry_ptr))
break;
entry = (struct acpi_pci_routing_table *)
((unsigned long)entry + entry->length);
}
kfree(buffer.pointer);
return 0;
}
/* --------------------------------------------------------------------------
PCI Interrupt Routing Support
-------------------------------------------------------------------------- */
#ifdef CONFIG_X86_IO_APIC
extern int noioapicquirk;
extern int noioapicreroute;
static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
{
struct pci_bus *bus_it;
for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
if (!bus_it->self)
return 0;
if (bus_it->self->irq_reroute_variant)
return bus_it->self->irq_reroute_variant;
}
return 0;
}
/*
* Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ
* entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does
* during interrupt handling). When this INTx generation cannot be disabled,
* we reroute these interrupts to their legacy equivalent to get rid of
* spurious interrupts.
*/
static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
struct acpi_prt_entry *entry)
{
if (noioapicquirk || noioapicreroute) {
return 0;
} else {
switch (bridge_has_boot_interrupt_variant(dev->bus)) {
case 0:
/* no rerouting necessary */
return 0;
case INTEL_IRQ_REROUTE_VARIANT:
/*
* Remap according to INTx routing table in 6700PXH
* specs, intel order number 302628-002, section
* 2.15.2. Other chipsets (80332, ...) have the same
* mapping and are handled here as well.
*/
dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy "
"IRQ %d\n", entry->index,
(entry->index % 4) + 16);
entry->index = (entry->index % 4) + 16;
return 1;
default:
dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy "
"IRQ: unknown mapping\n", entry->index);
return -1;
}
}
}
#endif /* CONFIG_X86_IO_APIC */
static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
{
struct acpi_prt_entry *entry = NULL;
struct pci_dev *bridge;
u8 bridge_pin, orig_pin = pin;
int ret;
ret = acpi_pci_irq_find_prt_entry(dev, pin, &entry);
if (!ret && entry) {
#ifdef CONFIG_X86_IO_APIC
acpi_reroute_boot_interrupt(dev, entry);
#endif /* CONFIG_X86_IO_APIC */
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
pci_name(dev), pin_name(pin)));
return entry;
}
/*
* Attempt to derive an IRQ for this device from a parent bridge's
* PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
*/
bridge = dev->bus->self;
while (bridge) {
pin = pci_swizzle_interrupt_pin(dev, pin);
if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
/* PC card has the same IRQ as its cardbridge */
bridge_pin = bridge->pin;
if (!bridge_pin) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"No interrupt pin configured for device %s\n",
pci_name(bridge)));
return NULL;
}
pin = bridge_pin;
}
ret = acpi_pci_irq_find_prt_entry(bridge, pin, &entry);
if (!ret && entry) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Derived GSI for %s INT %c from %s\n",
pci_name(dev), pin_name(orig_pin),
pci_name(bridge)));
return entry;
}
dev = bridge;
bridge = dev->bus->self;
}
dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
pin_name(orig_pin));
return NULL;
}
#if IS_ENABLED(CONFIG_ISA) || IS_ENABLED(CONFIG_EISA)
static int acpi_isa_register_gsi(struct pci_dev *dev)
{
u32 dev_gsi;
/* Interrupt Line values above 0xF are forbidden */
if (dev->irq > 0 && (dev->irq <= 0xF) &&
(acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) {
dev_warn(&dev->dev, "PCI INT %c: no GSI - using ISA IRQ %d\n",
pin_name(dev->pin), dev->irq);
acpi_register_gsi(&dev->dev, dev_gsi,
ACPI_LEVEL_SENSITIVE,
ACPI_ACTIVE_LOW);
return 0;
}
return -EINVAL;
}
#else
static inline int acpi_isa_register_gsi(struct pci_dev *dev)
{
return -ENODEV;
}
#endif
int acpi_pci_irq_enable(struct pci_dev *dev)
{
struct acpi_prt_entry *entry;
int gsi;
u8 pin;
int triggering = ACPI_LEVEL_SENSITIVE;
int polarity = ACPI_ACTIVE_LOW;
char *link = NULL;
char link_desc[16];
int rc;
pin = dev->pin;
if (!pin) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"No interrupt pin configured for device %s\n",
pci_name(dev)));
return 0;
}
if (dev->irq_managed && dev->irq > 0)
return 0;
entry = acpi_pci_irq_lookup(dev, pin);
if (!entry) {
/*
* IDE legacy mode controller IRQs are magic. Why do compat
* extensions always make such a nasty mess.
*/
if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
(dev->class & 0x05) == 0)
return 0;
}
if (entry) {
if (entry->link)
gsi = acpi_pci_link_allocate_irq(entry->link,
entry->index,
&triggering, &polarity,
&link);
else
gsi = entry->index;
} else
gsi = -1;
/*
* No IRQ known to the ACPI subsystem - maybe the BIOS /
* driver reported one, then use it. Exit in any case.
*/
if (gsi < 0) {
if (acpi_isa_register_gsi(dev))
dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
pin_name(pin));
kfree(entry);
return 0;
}
rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
if (rc < 0) {
dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
pin_name(pin));
kfree(entry);
return rc;
}
dev->irq = rc;
dev->irq_managed = 1;
if (link)
snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
else
link_desc[0] = '\0';
dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
pin_name(pin), link_desc, gsi,
(triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
(polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
kfree(entry);
return 0;
}
void acpi_pci_irq_disable(struct pci_dev *dev)
{
struct acpi_prt_entry *entry;
int gsi;
u8 pin;
pin = dev->pin;
if (!pin || !dev->irq_managed || dev->irq <= 0)
return;
/* Keep IOAPIC pin configuration when suspending */
if (dev->dev.power.is_prepared)
return;
#ifdef CONFIG_PM
if (dev->dev.power.runtime_status == RPM_SUSPENDING)
return;
#endif
entry = acpi_pci_irq_lookup(dev, pin);
if (!entry)
return;
if (entry->link)
gsi = acpi_pci_link_free_irq(entry->link);
else
gsi = entry->index;
kfree(entry);
/*
* TBD: It might be worth clearing dev->irq by magic constant
* (e.g. PCI_UNDEFINED_IRQ).
*/
dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
if (gsi >= 0) {
acpi_unregister_gsi(gsi);
dev->irq_managed = 0;
}
}