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Message-ID: <5988763.6WpnEvTV2f@vostro.rjw.lan>
Date: Tue, 12 Feb 2013 21:22:32 +0100
From: "Rafael J. Wysocki" <rjw@...k.pl>
To: Yinghai Lu <yinghai@...nel.org>
Cc: Bjorn Helgaas <bhelgaas@...gle.com>, linux-pci@...r.kernel.org,
linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ACPI, PCI: Get PRT entry during acpi_pci_enable_irq()
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@...leysoftware.com>
> Suggested-by: Bjorn Helgaas <bhelgaas@...gle.com>
> Signed-off-by: Yinghai Lu <yinghai@...nel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> ---
> 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(-)
>
> 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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