/*
* pci_irq.c - ACPI PCI Interrupt Routing ($Revision: 11 $)
*
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
* Copyright (C) 2002 Dominik Brodowski <devel@brodo.de>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/pm.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#define _COMPONENT ACPI_PCI_COMPONENT
ACPI_MODULE_NAME("pci_irq");
static struct acpi_prt_list acpi_prt;
static DEFINE_SPINLOCK(acpi_prt_lock);
/* --------------------------------------------------------------------------
PCI IRQ Routing Table (PRT) Support
-------------------------------------------------------------------------- */
static struct acpi_prt_entry *acpi_pci_irq_find_prt_entry(int segment,
int bus,
int device, int pin)
{
struct acpi_prt_entry *entry = NULL;
if (!acpi_prt.count)
return NULL;
/*
* Parse through all PRT entries looking for a match on the specified
* PCI device's segment, bus, device, and pin (don't care about func).
*
*/
spin_lock(&acpi_prt_lock);
list_for_each_entry(entry, &acpi_prt.entries, node) {
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;
}
static int
acpi_pci_irq_add_entry(acpi_handle handle,
int segment, int bus, struct acpi_pci_routing_table *prt)
{
struct acpi_prt_entry *entry = NULL;
if (!prt)
return -EINVAL;
entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
if (!entry)
return -ENOMEM;
entry->id.segment = segment;
entry->id.bus = bus;
entry->id.device = (prt->address >> 16) & 0xFFFF;
entry->id.function = prt->address & 0xFFFF;
entry->pin = prt->pin;
/*
* Type 1: Dynamic
* ---------------
* The 'source' field specifies the PCI interrupt link device used to
* configure the IRQ assigned to this slot|dev|pin. The 'source_index'
* indicates which resource descriptor in the resource template (of
* the link device) this interrupt is allocated from.
*
* NOTE: Don't query the Link Device for IRQ information at this time
* because Link Device enumeration may not have occurred yet
* (e.g. exists somewhere 'below' this _PRT entry in the ACPI
* namespace).
*/
if (prt->source[0]) {
acpi_get_handle(handle, prt->source, &entry->link.handle);
entry->link.index = prt->source_index;
}
/*
* Type 2: Static
* --------------
* The 'source' field is NULL, and the 'source_index' field specifies
* the IRQ value, which is hardwired to specific interrupt inputs on
* the interrupt controller.
*/
else
entry->link.index = prt->source_index;
ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
" %02X:%02X:%02X[%c] -> %s[%d]\n",
entry->id.segment, entry->id.bus,
entry->id.device, ('A' + entry->pin), prt->source,
entry->link.index));
spin_lock(&acpi_prt_lock);
list_add_tail(&entry->node, &acpi_prt.entries);
acpi_prt.count++;
spin_unlock(&acpi_prt_lock);
return 0;
}
static void
acpi_pci_irq_del_entry(int segment, int bus, struct acpi_prt_entry *entry)
{
if (segment == entry->id.segment && bus == entry->id.bus) {
acpi_prt.count--;
list_del(&entry->node);
kfree(entry);
}
}
int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
{
acpi_status status = AE_OK;
char *pathname = NULL;
struct acpi_buffer buffer = { 0, NULL };
struct acpi_pci_routing_table *prt = NULL;
struct acpi_pci_routing_table *entry = NULL;
static int first_time = 1;
pathname = kzalloc(ACPI_PATHNAME_MAX, GFP_KERNEL);
if (!pathname)
return -ENOMEM;
if (first_time) {
acpi_prt.count = 0;
INIT_LIST_HEAD(&acpi_prt.entries);
first_time = 0;
}
/*
* NOTE: We're given a 'handle' to the _PRT object's parent device
* (either a PCI root bridge or PCI-PCI bridge).
*/
buffer.length = ACPI_PATHNAME_MAX;
buffer.pointer = pathname;
acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
pathname);
/*
* Evaluate this _PRT and add its entries to our global list (acpi_prt).
*/
buffer.length = 0;
buffer.pointer = NULL;
kfree(pathname);
status = acpi_get_irq_routing_table(handle, &buffer);
if (status != AE_BUFFER_OVERFLOW) {
ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]",
acpi_format_exception(status)));
return -ENODEV;
}
prt = kzalloc(buffer.length, GFP_KERNEL);
if (!prt) {
return -ENOMEM;
}
buffer.pointer = prt;
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 = prt;
while (entry && (entry->length > 0)) {
acpi_pci_irq_add_entry(handle, segment, bus, entry);
entry = (struct acpi_pci_routing_table *)
((unsigned long)entry + entry->length);
}
kfree(prt);
return 0;
}
void acpi_pci_irq_del_prt(int segment, int bus)
{
struct list_head *node = NULL, *n = NULL;
struct acpi_prt_entry *entry = NULL;
if (!acpi_prt.count) {
return;
}
printk(KERN_DEBUG
"ACPI: Delete PCI Interrupt Routing Table for %x:%x\n", segment,
bus);
spin_lock(&acpi_prt_lock);
list_for_each_safe(node, n, &acpi_prt.entries) {
entry = list_entry(node, struct acpi_prt_entry, node);
acpi_pci_irq_del_entry(segment, bus, entry);
}
spin_unlock(&acpi_prt_lock);
}
/* --------------------------------------------------------------------------
PCI Interrupt Routing Support
-------------------------------------------------------------------------- */
typedef int (*irq_lookup_func) (struct acpi_prt_entry *, int *, int *, char **);
static int
acpi_pci_allocate_irq(struct acpi_prt_entry *entry,
int *triggering, int *polarity, char **link)
{
int irq;
if (entry->link.handle) {
irq = acpi_pci_link_allocate_irq(entry->link.handle,
entry->link.index, triggering,
polarity, link);
if (irq < 0) {
printk(KERN_WARNING PREFIX
"Invalid IRQ link routing entry\n");
return -1;
}
} else {
irq = entry->link.index;
*triggering = ACPI_LEVEL_SENSITIVE;
*polarity = ACPI_ACTIVE_LOW;
}
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", irq));
return irq;
}
static int
acpi_pci_free_irq(struct acpi_prt_entry *entry,
int *triggering, int *polarity, char **link)
{
int irq;
if (entry->link.handle) {
irq = acpi_pci_link_free_irq(entry->link.handle);
} else {
irq = entry->link.index;
}
return irq;
}
/*
* acpi_pci_irq_lookup
* success: return IRQ >= 0
* failure: return -1
*/
static int
acpi_pci_irq_lookup(struct pci_bus *bus,
int device,
int pin,
int *triggering,
int *polarity, char **link, irq_lookup_func func)
{
struct acpi_prt_entry *entry = NULL;
int segment = pci_domain_nr(bus);
int bus_nr = bus->number;
int ret;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Searching for PRT entry for %02x:%02x:%02x[%c]\n",
segment, bus_nr, device, ('A' + pin)));
entry = acpi_pci_irq_find_prt_entry(segment, bus_nr, device, pin);
if (!entry) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n"));
return -1;
}
ret = func(entry, triggering, polarity, link);
return ret;
}
/*
* acpi_pci_irq_derive
* success: return IRQ >= 0
* failure: return < 0
*/
static int
acpi_pci_irq_derive(struct pci_dev *dev,
int pin,
int *triggering,
int *polarity, char **link, irq_lookup_func func)
{
struct pci_dev *bridge = dev;
int irq = -1;
u8 bridge_pin = 0;
if (!dev)
return -EINVAL;
/*
* 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).
*/
while (irq < 0 && bridge->bus->self) {
pin = (pin + PCI_SLOT(bridge->devfn)) % 4;
bridge = bridge->bus->self;
if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
/* PC card has the same IRQ as its cardbridge */
bridge_pin = bridge->pin;
if (!bridge_pin) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"No interrupt pin configured for device %s\n",
pci_name(bridge)));
return -1;
}
/* Pin is from 0 to 3 */
bridge_pin--;
pin = bridge_pin;
}
irq = acpi_pci_irq_lookup(bridge->bus, PCI_SLOT(bridge->devfn),
pin, triggering, polarity,
link, func);
}
if (irq < 0) {
printk(KERN_WARNING PREFIX "Unable to derive IRQ for device %s\n",
pci_name(dev));
return -1;
}
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n",
irq, pci_name(dev), pci_name(bridge)));
return irq;
}
/*
* acpi_pci_irq_enable
* success: return 0
* failure: return < 0
*/
int acpi_pci_irq_enable(struct pci_dev *dev)
{
int irq = 0;
u8 pin = 0;
int triggering = ACPI_LEVEL_SENSITIVE;
int polarity = ACPI_ACTIVE_LOW;
char *link = NULL;
int rc;
if (!dev)
return -EINVAL;
pin = dev->pin;
if (!pin) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"No interrupt pin configured for device %s\n",
pci_name(dev)));
return 0;
}
pin--;
if (!dev->bus) {
printk(KERN_ERR PREFIX "Invalid (NULL) 'bus' field\n");
return -ENODEV;
}
/*
* First we check the PCI IRQ routing table (PRT) for an IRQ. PRT
* values override any BIOS-assigned IRQs set during boot.
*/
irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
&triggering, &polarity, &link,
acpi_pci_allocate_irq);
/*
* If no PRT entry was found, we'll try to derive an IRQ from the
* device's parent bridge.
*/
if (irq < 0)
irq = acpi_pci_irq_derive(dev, pin, &triggering,
&polarity, &link,
acpi_pci_allocate_irq);
if (irq < 0) {
/*
* IDE legacy mode controller IRQs are magic. Why do compat
* extensions always make such a nasty mess.
*/
if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
(dev->class & 0x05) == 0)
return 0;
}
/*
* No IRQ known to the ACPI subsystem - maybe the BIOS /
* driver reported one, then use it. Exit in any case.
*/
if (irq < 0) {
printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI",
pci_name(dev), ('A' + pin));
/* Interrupt Line values above 0xF are forbidden */
if (dev->irq > 0 && (dev->irq <= 0xF)) {
printk(" - using IRQ %d\n", dev->irq);
acpi_register_gsi(dev->irq, ACPI_LEVEL_SENSITIVE,
ACPI_ACTIVE_LOW);
return 0;
} else {
printk("\n");
return 0;
}
}
rc = acpi_register_gsi(irq, triggering, polarity);
if (rc < 0) {
printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: failed "
"to register GSI\n", pci_name(dev), ('A' + pin));
return rc;
}
dev->irq = rc;
printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ",
pci_name(dev), 'A' + pin);
if (link)
printk("Link [%s] -> ", link);
printk("GSI %u (%s, %s) -> IRQ %d\n", irq,
(triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
(polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
return 0;
}
/* FIXME: implement x86/x86_64 version */
void __attribute__ ((weak)) acpi_unregister_gsi(u32 i)
{
}
void acpi_pci_irq_disable(struct pci_dev *dev)
{
int gsi = 0;
u8 pin = 0;
int triggering = ACPI_LEVEL_SENSITIVE;
int polarity = ACPI_ACTIVE_LOW;
if (!dev || !dev->bus)
return;
pin = dev->pin;
if (!pin)
return;
pin--;
/*
* First we check the PCI IRQ routing table (PRT) for an IRQ.
*/
gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
&triggering, &polarity, NULL,
acpi_pci_free_irq);
/*
* If no PRT entry was found, we'll try to derive an IRQ from the
* device's parent bridge.
*/
if (gsi < 0)
gsi = acpi_pci_irq_derive(dev, pin,
&triggering, &polarity, NULL,
acpi_pci_free_irq);
if (gsi < 0)
return;
/*
* TBD: It might be worth clearing dev->irq by magic constant
* (e.g. PCI_UNDEFINED_IRQ).
*/
printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n",
pci_name(dev));
acpi_unregister_gsi(gsi);
return;
}
