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Commit 181380b7 authored by Yinghai Lu's avatar Yinghai Lu Committed by Bjorn Helgaas
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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 4f535093 ("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: default avatarPeter Hurley <peter@hurleysoftware.com>
Suggested-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent be6d2867

drivers/acpi/pci_irq.c

+34 −68
Original line number Diff line number Diff line
@@ -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);

	if (dev->bus->bridge)

		handle = ACPI_HANDLE(dev->bus->bridge);



	kfree(buffer.pointer);



	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 */
@@ -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).

drivers/acpi/pci_root.c

+0 −18
Original line number Diff line number Diff line
@@ -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);

drivers/pci/pci-acpi.c

+0 −24
Original line number Diff line number Diff line
@@ -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 = {

include/acpi/acpi_drivers.h

+0 −5
Original line number Diff line number Diff line
@@ -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;