Re: [PATCH] ACPI, PCI: Get PRT entry during acpi_pci_enable_irq()
From: Yinghai Lu
Date: Thu Feb 14 2013 - 19:51:00 EST
On Tue, Feb 12, 2013 at 12:22 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> On Tuesday, February 12, 2013 11:11:23 AM Yinghai Lu wrote:
>> Peter Hurley found "irq 18 nobody cared" with pci-next, and dmesg has
>>
>> [ 8.983246] pci 0000:00:1e.0: can't derive routing for PCI INT A
>> [ 8.983600] snd_ctxfi 0000:09:02.0: PCI INT A: no GSI - using ISA IRQ 5
>>
>> bisect to
>> | commit 4f535093cf8f6da8cfda7c36c2c1ecd2e9586ee4
>> | PCI: Put pci_dev in device tree as early as possible
>>
>> It turns out we need to call acpi_pci_irq_add_prt() after the pci bridges
>> are scanned.
>>
>> Bjorn said:
>> The bus number binding means acpi_pci_irq_add_prt() has to happen
>> after enumerating everything below a bridge, and it will prevent us
>> from doing any bus number reassignment for hotplug.
>>
>> I think we should remove the bus numbers from the cached _PRT (or
>> maybe even remove the _PRT caching completely). When we enable a PCI
>> device's IRQ, we should search up the PCI device tree looking for a
>> _PRT associated with each node, and applying normal PCI bridge
>> swizzling when we don't find a _PRT. I think this can be done without
>> using PCI bus numbers at all.
>>
>> So here we try to remove _PRT caching completely.
>>
>> -v2: check !handle early.
>>
>> Reported-and-tested-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
>> Suggested-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
>
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
>> ---
>> drivers/acpi/pci_irq.c | 95 +++++++++++++++++---------------------------
>> drivers/acpi/pci_root.c | 18 --------
>> drivers/pci/pci-acpi.c | 24 -----------
>> include/acpi/acpi_drivers.h | 5 --
>> 4 files changed, 38 insertions(+), 104 deletions(-)
Bjorn,
Can you put this one into pci/next?
Thanks
Yinghai
>>
>> Index: linux-2.6/drivers/acpi/pci_irq.c
>> ===================================================================
>> --- linux-2.6.orig/drivers/acpi/pci_irq.c
>> +++ linux-2.6/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_pr
>> }
>> }
>>
>> -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;
>> @@ -237,26 +220,33 @@ static int acpi_pci_irq_add_entry(acpi_h
>> 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;
>> +
>> + 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_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);
>> + dev_printk(KERN_DEBUG, &dev->dev,
>> + "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
>> + (char *) buffer.pointer);
>>
>> kfree(buffer.pointer);
>>
>> @@ -273,7 +263,9 @@ int acpi_pci_irq_add_prt(acpi_handle han
>>
>> 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 +274,6 @@ int acpi_pci_irq_add_prt(acpi_handle han
>> 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 +334,13 @@ static int acpi_reroute_boot_interrupt(s
>>
>> 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 +349,7 @@ static struct acpi_prt_entry *acpi_pci_i
>> 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 +369,8 @@ static struct acpi_prt_entry *acpi_pci_i
>> 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 +446,7 @@ int acpi_pci_irq_enable(struct pci_dev *
>> dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
>> pin_name(pin));
>> }
>> +
>> return 0;
>> }
>>
>> @@ -477,6 +454,7 @@ int acpi_pci_irq_enable(struct pci_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 +469,7 @@ int acpi_pci_irq_enable(struct pci_dev *
>> (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
>> (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
>>
>> + kfree(entry);
>> return 0;
>> }
>>
>> @@ -513,6 +492,8 @@ void acpi_pci_irq_disable(struct pci_dev
>> else
>> gsi = entry->index;
>>
>> + kfree(entry);
>> +
>> /*
>> * TBD: It might be worth clearing dev->irq by magic constant
>> * (e.g. PCI_UNDEFINED_IRQ).
>> Index: linux-2.6/drivers/acpi/pci_root.c
>> ===================================================================
>> --- linux-2.6.orig/drivers/acpi/pci_root.c
>> +++ linux-2.6/drivers/acpi/pci_root.c
>> @@ -413,7 +413,6 @@ static int acpi_pci_root_add(struct acpi
>> 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;
>> @@ -468,16 +467,6 @@ static int acpi_pci_root_add(struct acpi
>> 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);
>>
>> /*
>> @@ -602,7 +591,6 @@ 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;
>> @@ -610,8 +598,6 @@ end:
>>
>> static void acpi_pci_root_remove(struct acpi_device *device)
>> {
>> - acpi_status status;
>> - acpi_handle handle;
>> struct acpi_pci_root *root = acpi_driver_data(device);
>> struct acpi_pci_driver *driver;
>>
>> @@ -626,10 +612,6 @@ static void acpi_pci_root_remove(struct
>> 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);
>> Index: linux-2.6/drivers/pci/pci-acpi.c
>> ===================================================================
>> --- linux-2.6.orig/drivers/pci/pci-acpi.c
>> +++ linux-2.6/drivers/pci/pci-acpi.c
>> @@ -307,25 +307,6 @@ static void pci_acpi_setup(struct device
>> 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);
>> - }
>>
>> if (acpi_bus_get_device(handle, &adev) || !adev->wakeup.flags.valid)
>> return;
>> @@ -340,7 +321,6 @@ static void pci_acpi_setup(struct device
>>
>> 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;
>>
>> @@ -349,10 +329,6 @@ static void pci_acpi_cleanup(struct devi
>> device_set_run_wake(dev, false);
>> pci_acpi_remove_pm_notifier(adev);
>> }
>> -
>> - 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 = {
>> Index: linux-2.6/include/acpi/acpi_drivers.h
>> ===================================================================
>> --- linux-2.6.orig/include/acpi/acpi_drivers.h
>> +++ linux-2.6/include/acpi/acpi_drivers.h
>> @@ -90,11 +90,6 @@ int acpi_pci_link_allocate_irq(acpi_hand
>> 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;
> --
> I speak only for myself.
> Rafael J. Wysocki, Intel Open Source Technology Center.
> --
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