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>

diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
index 68a921d..41c5e1b 100644 (file)
--- 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).

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index fd59f57..8545b1d 100644 (file)
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -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;
@@ -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);
 
        /*
@@ -623,7 +612,6 @@ out_del_root:
        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;
@@ -631,8 +619,6 @@ end:
 
 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;
 
@@ -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);

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 42736e2..9ba9df5 100644 (file)
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -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)
@@ -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;
 
@@ -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 = {

diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h
index 8b1d7a6..627749a 100644 (file)
--- a/include/acpi/acpi_drivers.h
+++ b/include/acpi/acpi_drivers.h
@@ -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;