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PCI/ACPI: Don't cache _PRT, and don't associate them with bus numbers
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Previously, we cached _PRT (PCI routing table, ACPI 5.0 sec 6.2.12)
contents and associated each _PRT entry with a PCI bus number.  The bus
number association means dependencies on PCI device enumeration and bus
number assignment, as well as on the PCI/ACPI binding process.

After 4f53509 ("PCI: Put pci_dev in device tree as early as possible"),
these dependencies caused the IRQ issues reported by Peter:

    pci 0000:00:1e.0: PCI bridge to [bus 09] (subtractive decode)
    pci 0000:00:1e.0: can't derive routing for PCI INT A
    snd_ctxfi 0000:09:02.0: PCI INT A: no GSI - using ISA IRQ 5
    irq 18: nobody cared (try booting with the "irqpoll" option)

This patch removes _PRT caching.  Instead, we evaluate _PRT as needed
in the pci_enable_device() path.  This also removes the dependency on
PCI bus numbers: we can simply look at the _PRT associated with each
bridge as we walk upstream toward the root.

[bhelgaas: changelog]
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=53561
Reported-and-tested-by: Peter Hurley <[email protected]>
Suggested-by: Bjorn Helgaas <[email protected]>
Signed-off-by: Yinghai Lu <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
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Yinghai Lu authored and bjorn-helgaas committed Feb 16, 2013
1 parent be6d286 commit 181380b
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Showing 4 changed files with 34 additions and 115 deletions.
102 changes: 34 additions & 68 deletions drivers/acpi/pci_irq.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -53,9 +53,6 @@ struct acpi_prt_entry {
u32 index; /* GSI, or link _CRS index */
};

static LIST_HEAD(acpi_prt_list);
static DEFINE_SPINLOCK(acpi_prt_lock);

static inline char pin_name(int pin)
{
return 'A' + pin - 1;
Expand All @@ -65,28 +62,6 @@ static inline char pin_name(int pin)
PCI IRQ Routing Table (PRT) Support
-------------------------------------------------------------------------- */

static struct acpi_prt_entry *acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
int pin)
{
struct acpi_prt_entry *entry;
int segment = pci_domain_nr(dev->bus);
int bus = dev->bus->number;
int device = PCI_SLOT(dev->devfn);

spin_lock(&acpi_prt_lock);
list_for_each_entry(entry, &acpi_prt_list, list) {
if ((segment == entry->id.segment)
&& (bus == entry->id.bus)
&& (device == entry->id.device)
&& (pin == entry->pin)) {
spin_unlock(&acpi_prt_lock);
return entry;
}
}
spin_unlock(&acpi_prt_lock);
return NULL;
}

/* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
static const struct dmi_system_id medion_md9580[] = {
{
Expand Down Expand Up @@ -184,11 +159,19 @@ static void do_prt_fixups(struct acpi_prt_entry *entry,
}
}

static int acpi_pci_irq_add_entry(acpi_handle handle, int segment, int bus,
struct acpi_pci_routing_table *prt)
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;
Expand Down Expand Up @@ -237,43 +220,37 @@ static int acpi_pci_irq_add_entry(acpi_handle handle, int segment, int bus,
entry->id.device, pin_name(entry->pin),
prt->source, entry->index));

spin_lock(&acpi_prt_lock);
list_add_tail(&entry->list, &acpi_prt_list);
spin_unlock(&acpi_prt_lock);
*entry_ptr = entry;

return 0;
}

int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
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;

/* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
if (ACPI_FAILURE(status))
return -ENODEV;

printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
(char *) buffer.pointer);

kfree(buffer.pointer);
if (dev->bus->bridge)
handle = ACPI_HANDLE(dev->bus->bridge);

buffer.length = ACPI_ALLOCATE_BUFFER;
buffer.pointer = NULL;
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)) {
ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]",
acpi_format_exception(status)));
kfree(buffer.pointer);
return -ENODEV;
}

entry = buffer.pointer;
while (entry && (entry->length > 0)) {
acpi_pci_irq_add_entry(handle, segment, bus, entry);
if (!acpi_pci_irq_check_entry(handle, dev, pin,
entry, entry_ptr))
break;
entry = (struct acpi_pci_routing_table *)
((unsigned long)entry + entry->length);
}
Expand All @@ -282,23 +259,6 @@ int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
return 0;
}

void acpi_pci_irq_del_prt(int segment, int bus)
{
struct acpi_prt_entry *entry, *tmp;

printk(KERN_DEBUG
"ACPI: Delete PCI Interrupt Routing Table for %04x:%02x\n",
segment, bus);
spin_lock(&acpi_prt_lock);
list_for_each_entry_safe(entry, tmp, &acpi_prt_list, list) {
if (segment == entry->id.segment && bus == entry->id.bus) {
list_del(&entry->list);
kfree(entry);
}
}
spin_unlock(&acpi_prt_lock);
}

/* --------------------------------------------------------------------------
PCI Interrupt Routing Support
-------------------------------------------------------------------------- */
Expand Down Expand Up @@ -359,12 +319,13 @@ static int acpi_reroute_boot_interrupt(struct pci_dev *dev,

static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
{
struct acpi_prt_entry *entry;
struct acpi_prt_entry *entry = NULL;
struct pci_dev *bridge;
u8 bridge_pin, orig_pin = pin;
int ret;

entry = acpi_pci_irq_find_prt_entry(dev, pin);
if (entry) {
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 */
Expand All @@ -373,7 +334,7 @@ static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int 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).
*/
Expand All @@ -393,8 +354,8 @@ static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
pin = bridge_pin;
}

entry = acpi_pci_irq_find_prt_entry(bridge, pin);
if (entry) {
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),
Expand Down Expand Up @@ -470,13 +431,15 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
pin_name(pin));
}

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;
Expand All @@ -491,6 +454,7 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
(triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
(polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);

kfree(entry);
return 0;
}

Expand All @@ -513,6 +477,8 @@ void acpi_pci_irq_disable(struct pci_dev *dev)
else
gsi = entry->index;

kfree(entry);

/*
* TBD: It might be worth clearing dev->irq by magic constant
* (e.g. PCI_UNDEFINED_IRQ).
Expand Down
18 changes: 0 additions & 18 deletions drivers/acpi/pci_root.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -434,7 +434,6 @@ static int acpi_pci_root_add(struct acpi_device *device)
acpi_status status;
int result;
struct acpi_pci_root *root;
acpi_handle handle;
struct acpi_pci_driver *driver;
u32 flags, base_flags;
bool is_osc_granted = false;
Expand Down Expand Up @@ -489,16 +488,6 @@ static int acpi_pci_root_add(struct acpi_device *device)
acpi_device_name(device), acpi_device_bid(device),
root->segment, &root->secondary);

/*
* PCI Routing Table
* -----------------
* Evaluate and parse _PRT, if exists.
*/
status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
if (ACPI_SUCCESS(status))
result = acpi_pci_irq_add_prt(device->handle, root->segment,
root->secondary.start);

root->mcfg_addr = acpi_pci_root_get_mcfg_addr(device->handle);

/*
Expand Down Expand Up @@ -623,16 +612,13 @@ static int acpi_pci_root_add(struct acpi_device *device)
list_del(&root->node);
mutex_unlock(&acpi_pci_root_lock);

acpi_pci_irq_del_prt(root->segment, root->secondary.start);
end:
kfree(root);
return result;
}

static int acpi_pci_root_remove(struct acpi_device *device, int type)
{
acpi_status status;
acpi_handle handle;
struct acpi_pci_root *root = acpi_driver_data(device);
struct acpi_pci_driver *driver;

Expand All @@ -647,10 +633,6 @@ static int acpi_pci_root_remove(struct acpi_device *device, int type)
device_set_run_wake(root->bus->bridge, false);
pci_acpi_remove_bus_pm_notifier(device);

status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
if (ACPI_SUCCESS(status))
acpi_pci_irq_del_prt(root->segment, root->secondary.start);

pci_remove_root_bus(root->bus);

mutex_lock(&acpi_pci_root_lock);
Expand Down
24 changes: 0 additions & 24 deletions drivers/pci/pci-acpi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -325,25 +325,6 @@ static void pci_acpi_setup(struct device *dev)
struct pci_dev *pci_dev = to_pci_dev(dev);
acpi_handle handle = ACPI_HANDLE(dev);
struct acpi_device *adev;
acpi_status status;
acpi_handle dummy;

/*
* Evaluate and parse _PRT, if exists. This code allows parsing of
* _PRT objects within the scope of non-bridge devices. Note that
* _PRTs within the scope of a PCI bridge assume the bridge's
* subordinate bus number.
*
* TBD: Can _PRTs exist within the scope of non-bridge PCI devices?
*/
status = acpi_get_handle(handle, METHOD_NAME__PRT, &dummy);
if (ACPI_SUCCESS(status)) {
unsigned char bus;

bus = pci_dev->subordinate ?
pci_dev->subordinate->number : pci_dev->bus->number;
acpi_pci_irq_add_prt(handle, pci_domain_nr(pci_dev->bus), bus);
}

acpi_power_resource_register_device(dev, handle);
if (acpi_bus_get_device(handle, &adev) || !adev->wakeup.flags.valid)
Expand All @@ -359,7 +340,6 @@ static void pci_acpi_setup(struct device *dev)

static void pci_acpi_cleanup(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
acpi_handle handle = ACPI_HANDLE(dev);
struct acpi_device *adev;

Expand All @@ -369,10 +349,6 @@ static void pci_acpi_cleanup(struct device *dev)
pci_acpi_remove_pm_notifier(adev);
}
acpi_power_resource_unregister_device(dev, handle);

if (pci_dev->subordinate)
acpi_pci_irq_del_prt(pci_domain_nr(pci_dev->bus),
pci_dev->subordinate->number);
}

static struct acpi_bus_type acpi_pci_bus = {
Expand Down
5 changes: 0 additions & 5 deletions include/acpi/acpi_drivers.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -90,11 +90,6 @@ int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
int *polarity, char **name);
int acpi_pci_link_free_irq(acpi_handle handle);

/* ACPI PCI Interrupt Routing (pci_irq.c) */

int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus);
void acpi_pci_irq_del_prt(int segment, int bus);

/* ACPI PCI Device Binding (pci_bind.c) */

struct pci_bus;
Expand Down

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