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authorYinghai Lu <yinghai@kernel.org>2013-02-16 11:58:34 -0700
committerBjorn Helgaas <bhelgaas@google.com>2013-02-16 11:58:34 -0700
commit181380b702eee1a9aca51354d7b87c7b08541fcf (patch)
treec95dc8c7649fe97c18a99d3ee69ad014adf8cfaa /drivers/acpi/pci_irq.c
parentbe6d2867b4f68a575c78fa368abd3ad49980c514 (diff)
downloadlinux-linaro-stable-181380b702eee1a9aca51354d7b87c7b08541fcf.tar.gz
PCI/ACPI: Don't cache _PRT, and don't associate them with bus numbers
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 4f535093cf ("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 <peter@hurleysoftware.com> Suggested-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/acpi/pci_irq.c')
-rw-r--r--drivers/acpi/pci_irq.c102
1 files changed, 34 insertions, 68 deletions
diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
index 68a921d03247..41c5e1b799ef 100644
--- a/drivers/acpi/pci_irq.c
+++ b/drivers/acpi/pci_irq.c
@@ -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;
@@ -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[] = {
{
@@ -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;
@@ -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);
}
@@ -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
-------------------------------------------------------------------------- */
@@ -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 */
@@ -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).
*/
@@ -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),
@@ -470,6 +431,7 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
pin_name(pin));
}
+
return 0;
}
@@ -477,6 +439,7 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
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;
@@ -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;
}
@@ -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).