/*
* Low-Level PCI Support for PC -- Routing of Interrupts
*
* (c) 1999--2000 Martin Mares <mj@suse.cz>
*/
#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/malloc.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/io_apic.h>
#include "pci-i386.h"
#define PIRQ_SIGNATURE (('$' << 0) + ('P' << 8) + ('I' << 16) + ('R' << 24))
#define PIRQ_VERSION 0x0100
static struct irq_routing_table *pirq_table;
/*
* Never use: 0, 1, 2 (timer, keyboard, and cascade)
* Avoid using: 13, 14 and 15 (FP error and IDE).
* Penalize: 3, 4, 6, 7, 12 (known ISA uses: serial, floppy, parallel and mouse)
*/
unsigned int pcibios_irq_mask = 0xfff8;
static int pirq_penalty[16] = {
1000000, 1000000, 1000000, 1000, 1000, 0, 1000, 1000,
0, 0, 0, 0, 1000, 100000, 100000, 100000
};
struct irq_router {
char *name;
u16 vendor, device;
int (*get)(struct pci_dev *router, struct pci_dev *dev, int pirq);
int (*set)(struct pci_dev *router, struct pci_dev *dev, int pirq, int new);
};
/*
* Search 0xf0000 -- 0xfffff for the PCI IRQ Routing Table.
*/
50 static struct irq_routing_table * __init pirq_find_routing_table(void)
{
u8 *addr;
struct irq_routing_table *rt;
int i;
u8 sum;
57 for(addr = (u8 *) __va(0xf0000); addr < (u8 *) __va(0x100000); addr += 16) {
rt = (struct irq_routing_table *) addr;
if (rt->signature != PIRQ_SIGNATURE ||
rt->version != PIRQ_VERSION ||
rt->size % 16 ||
62 rt->size < sizeof(struct irq_routing_table))
63 continue;
sum = 0;
65 for(i=0; i<rt->size; i++)
sum += addr[i];
67 if (!sum) {
DBG("PCI: Interrupt Routing Table found at 0x%p\n", rt);
69 return rt;
}
}
72 return NULL;
}
/*
* If we have a IRQ routing table, use it to search for peer host
* bridges. It's a gross hack, but since there are no other known
* ways how to get a list of buses, we have to go this way.
*/
81 static void __init pirq_peer_trick(void)
{
struct irq_routing_table *rt = pirq_table;
u8 busmap[256];
int i;
struct irq_info *e;
memset(busmap, 0, sizeof(busmap));
89 for(i=0; i < (rt->size - sizeof(struct irq_routing_table)) / sizeof(struct irq_info); i++) {
e = &rt->slots[i];
#ifdef DEBUG
{
int j;
DBG("%02x:%02x slot=%02x", e->bus, e->devfn/8, e->slot);
for(j=0; j<4; j++)
DBG(" %d:%02x/%04x", j, e->irq[j].link, e->irq[j].bitmap);
DBG("\n");
}
#endif
busmap[e->bus] = 1;
}
102 for(i=1; i<256; i++)
/*
* It might be a secondary bus, but in this case its parent is already
* known (ascending bus order) and therefore pci_scan_bus returns immediately.
*/
107 if (busmap[i] && pci_scan_bus(i, pci_root_bus->ops, NULL))
printk("PCI: Discovered primary peer bus %02x [IRQ]\n", i);
pcibios_last_bus = -1;
}
/*
* Code for querying and setting of IRQ routes on various interrupt routers.
*/
116 static void eisa_set_level_irq(unsigned int irq)
{
unsigned char mask = 1 << (irq & 7);
unsigned int port = 0x4d0 + (irq >> 3);
unsigned char val = inb(port);
122 if (!(val & mask)) {
DBG(" -> edge");
outb(val | mask, port);
}
}
/*
* Common IRQ routing practice: nybbles in config space,
* offset by some magic constant.
*/
132 static unsigned int read_config_nybble(struct pci_dev *router, unsigned offset, unsigned nr)
{
u8 x;
unsigned reg = offset + (nr >> 1);
pci_read_config_byte(router, reg, &x);
138 return (nr & 1) ? (x >> 4) : (x & 0xf);
}
141 static void write_config_nybble(struct pci_dev *router, unsigned offset, unsigned nr, unsigned int val)
{
u8 x;
unsigned reg = offset + (nr >> 1);
pci_read_config_byte(router, reg, &x);
x = (nr & 1) ? ((x & 0x0f) | (val << 4)) : ((x & 0xf0) | val);
pci_write_config_byte(router, reg, x);
}
/*
* ALI pirq entries are damn ugly, and completely undocumented.
* This has been figured out from pirq tables, and it's not a pretty
* picture.
*/
156 static int pirq_ali_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
static unsigned char irqmap[16] = { 0, 9, 3, 10, 4, 5, 7, 6, 1, 11, 0, 12, 0, 14, 0, 15 };
160 return irqmap[read_config_nybble(router, 0x48, pirq-1)];
}
163 static int pirq_ali_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
static unsigned char irqmap[16] = { 0, 8, 0, 2, 4, 5, 7, 6, 0, 1, 3, 9, 11, 0, 13, 15 };
unsigned int val = irqmap[irq];
168 if (val) {
write_config_nybble(router, 0x48, pirq-1, val);
170 return 1;
}
172 return 0;
}
/*
* The Intel PIIX4 pirq rules are fairly simple: "pirq" is
* just a pointer to the config space.
*/
179 static int pirq_piix_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
u8 x;
pci_read_config_byte(router, pirq, &x);
184 return (x < 16) ? x : 0;
}
187 static int pirq_piix_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
pci_write_config_byte(router, pirq, irq);
190 return 1;
}
/*
* The VIA pirq rules are nibble-based, like ALI,
* but without the ugly irq number munging.
*/
197 static int pirq_via_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
199 return read_config_nybble(router, 0x55, pirq);
}
202 static int pirq_via_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
write_config_nybble(router, 0x55, pirq, irq);
205 return 1;
}
/*
* OPTI: high four bits are nibble pointer..
* I wonder what the low bits do?
*/
212 static int pirq_opti_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
214 return read_config_nybble(router, 0xb8, pirq >> 4);
}
217 static int pirq_opti_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
write_config_nybble(router, 0xb8, pirq >> 4, irq);
220 return 1;
}
/*
* Cyrix: nibble offset 0x5C
*/
226 static int pirq_cyrix_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
228 return read_config_nybble(router, 0x5C, pirq-1);
}
231 static int pirq_cyrix_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
write_config_nybble(router, 0x5C, pirq-1, irq);
234 return 1;
}
237 static int pirq_sis_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
u8 x;
int reg = 0x41 + (pirq - 'A') ;
pci_read_config_byte(router, reg, &x);
243 return (x & 0x80) ? 0 : (x & 0x0f);
}
246 static int pirq_sis_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
u8 x;
int reg = 0x41 + (pirq - 'A') ;
pci_read_config_byte(router, reg, &x);
x = (pirq & 0x20) ? 0 : (irq & 0x0f);
pci_write_config_byte(router, reg, x);
255 return 1;
}
/*
* VLSI: nibble offset 0x74 - educated guess due to routing table and
* config space of VLSI 82C534 PCI-bridge/router (1004:0102)
* Tested on HP OmniBook 800 covering PIRQ 1, 2, 4, 8 for onboard
* devices, PIRQ 3 for non-pci(!) soundchip and (untested) PIRQ 6
* for the busbridge to the docking station.
*/
266 static int pirq_vlsi_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
268 if (pirq > 8) {
printk("VLSI router pirq escape (%d)\n", pirq);
270 return 0;
}
272 return read_config_nybble(router, 0x74, pirq-1);
}
275 static int pirq_vlsi_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
277 if (pirq > 8) {
printk("VLSI router pirq escape (%d)\n", pirq);
279 return 0;
}
write_config_nybble(router, 0x74, pirq-1, irq);
282 return 1;
}
/*
* ServerWorks: PCI interrupts mapped to system IRQ lines through Index
* and Redirect I/O registers (0x0c00 and 0x0c01). The Index register
* format is (PCIIRQ## | 0x10), e.g.: PCIIRQ10=0x1a. The Redirect
* register is a straight binary coding of desired PIC IRQ (low nibble).
*
* The 'link' value in the PIRQ table is already in the correct format
* for the Index register. There are some special index values:
* 0x00 for ACPI (SCI), 0x01 for USB, 0x02 for IDE0, 0x04 for IDE1,
* and 0x03 for SMBus.
*/
296 static int pirq_serverworks_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
outb_p(pirq, 0xc00);
299 return inb(0xc01) & 0xf;
}
302 static int pirq_serverworks_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
outb_p(pirq, 0xc00);
outb_p(irq, 0xc01);
306 return 1;
}
#ifdef CONFIG_PCI_BIOS
311 static int pirq_bios_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
struct pci_dev *bridge;
int pin = pci_get_interrupt_pin(dev, &bridge);
315 return pcibios_set_irq_routing(bridge, pin, irq);
}
static struct irq_router pirq_bios_router =
{ "BIOS", 0, 0, NULL, pirq_bios_set };
#endif
static struct irq_router pirq_routers[] = {
{ "PIIX", PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371FB_0, pirq_piix_get, pirq_piix_set },
{ "PIIX", PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371SB_0, pirq_piix_get, pirq_piix_set },
{ "PIIX", PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_0, pirq_piix_get, pirq_piix_set },
{ "PIIX", PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371MX, pirq_piix_get, pirq_piix_set },
{ "PIIX", PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443MX_0, pirq_piix_get, pirq_piix_set },
{ "ALI", PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533, pirq_ali_get, pirq_ali_set },
{ "VIA", PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_0, pirq_via_get, pirq_via_set },
{ "VIA", PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596, pirq_via_get, pirq_via_set },
{ "VIA", PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686, pirq_via_get, pirq_via_set },
{ "OPTI", PCI_VENDOR_ID_OPTI, PCI_DEVICE_ID_OPTI_82C700, pirq_opti_get, pirq_opti_set },
{ "NatSemi", PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5520, pirq_cyrix_get, pirq_cyrix_set },
{ "SIS", PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503, pirq_sis_get, pirq_sis_set },
{ "VLSI 82C534", PCI_VENDOR_ID_VLSI, PCI_DEVICE_ID_VLSI_82C534, pirq_vlsi_get, pirq_vlsi_set },
{ "ServerWorks", PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_OSB4,
pirq_serverworks_get, pirq_serverworks_set },
{ "default", 0, 0, NULL, NULL }
};
static struct irq_router *pirq_router;
static struct pci_dev *pirq_router_dev;
350 static void __init pirq_find_router(void)
{
struct irq_routing_table *rt = pirq_table;
struct irq_router *r;
#ifdef CONFIG_PCI_BIOS
356 if (!rt->signature) {
printk("PCI: Using BIOS for IRQ routing\n");
pirq_router = &pirq_bios_router;
359 return;
}
#endif
/* fall back to default router if nothing else found */
pirq_router = pirq_routers + sizeof(pirq_routers) / sizeof(pirq_routers[0]) - 1;
pirq_router_dev = pci_find_slot(rt->rtr_bus, rt->rtr_devfn);
366 if (!pirq_router_dev) {
DBG("PCI: Interrupt router not found at %02x:%02x\n", rt->rtr_bus, rt->rtr_devfn);
368 return;
}
371 for(r=pirq_routers; r->vendor; r++) {
/* Exact match against router table entry? Use it! */
373 if (r->vendor == rt->rtr_vendor && r->device == rt->rtr_device) {
pirq_router = r;
375 break;
}
/* Match against router device entry? Use it as a fallback */
378 if (r->vendor == pirq_router_dev->vendor && r->device == pirq_router_dev->device) {
pirq_router = r;
}
}
printk("PCI: Using IRQ router %s [%04x/%04x] at %s\n",
pirq_router->name,
pirq_router_dev->vendor,
pirq_router_dev->device,
pirq_router_dev->slot_name);
}
389 static struct irq_info *pirq_get_info(struct pci_dev *dev)
{
struct irq_routing_table *rt = pirq_table;
int entries = (rt->size - sizeof(struct irq_routing_table)) / sizeof(struct irq_info);
struct irq_info *info;
395 for (info = rt->slots; entries--; info++)
396 if (info->bus == dev->bus->number && PCI_SLOT(info->devfn) == PCI_SLOT(dev->devfn))
397 return info;
398 return NULL;
}
401 static void pcibios_test_irq_handler(int irq, void *dev_id, struct pt_regs *regs)
{
}
405 static int pcibios_lookup_irq(struct pci_dev *dev, int assign)
{
u8 pin;
struct irq_info *info;
int i, pirq, newirq;
int irq = 0;
u32 mask;
struct irq_router *r = pirq_router;
struct pci_dev *dev2;
char *msg = NULL;
416 if (!pirq_table)
417 return 0;
/* Find IRQ routing entry */
pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
421 if (!pin) {
DBG(" -> no interrupt pin\n");
423 return 0;
}
pin = pin - 1;
DBG("IRQ for %s:%d", dev->slot_name, pin);
info = pirq_get_info(dev);
429 if (!info) {
DBG(" -> not found in routing table\n");
431 return 0;
}
pirq = info->irq[pin].link;
mask = info->irq[pin].bitmap;
435 if (!pirq) {
DBG(" -> not routed\n");
437 return 0;
}
DBG(" -> PIRQ %02x, mask %04x, excl %04x", pirq, mask, pirq_table->exclusive_irqs);
mask &= pcibios_irq_mask;
/*
* Find the best IRQ to assign: use the one
* reported by the device if possible.
*/
newirq = dev->irq;
447 if (!newirq && assign) {
448 for (i = 0; i < 16; i++) {
449 if (!(mask & (1 << i)))
450 continue;
if (pirq_penalty[i] < pirq_penalty[newirq] &&
452 !request_irq(i, pcibios_test_irq_handler, SA_SHIRQ, "pci-test", dev)) {
free_irq(i, dev);
newirq = i;
}
}
}
DBG(" -> newirq=%d", newirq);
/* Check if it is hardcoded */
461 if ((pirq & 0xf0) == 0xf0) {
irq = pirq & 0xf;
DBG(" -> hardcoded IRQ %d\n", irq);
msg = "Hardcoded";
465 if (dev->irq && dev->irq != irq) {
printk("IRQ routing conflict in pirq table! Try 'pci=autoirq'\n");
467 return 0;
}
469 } else if (r->get && (irq = r->get(pirq_router_dev, dev, pirq))) {
DBG(" -> got IRQ %d\n", irq);
msg = "Found";
/* We refuse to override the dev->irq information. Give a warning! */
473 if (dev->irq && dev->irq != irq) {
printk("IRQ routing conflict in pirq table! Try 'pci=autoirq'\n");
475 return 0;
}
477 } else if (newirq && r->set && (dev->class >> 8) != PCI_CLASS_DISPLAY_VGA) {
DBG(" -> assigning IRQ %d", newirq);
479 if (r->set(pirq_router_dev, dev, pirq, newirq)) {
eisa_set_level_irq(newirq);
DBG(" ... OK\n");
msg = "Assigned";
irq = newirq;
}
}
487 if (!irq) {
DBG(" ... failed\n");
489 if (newirq && mask == (1 << newirq)) {
msg = "Guessed";
irq = newirq;
492 } else
493 return 0;
}
printk("PCI: %s IRQ %d for device %s\n", msg, irq, dev->slot_name);
/* Update IRQ for all devices with the same pirq value */
498 pci_for_each_dev(dev2) {
pci_read_config_byte(dev2, PCI_INTERRUPT_PIN, &pin);
if (!pin)
continue;
pin--;
info = pirq_get_info(dev2);
if (!info)
continue;
if (info->irq[pin].link == pirq) {
dev2->irq = irq;
pirq_penalty[irq]++;
if (dev != dev2)
printk("PCI: The same IRQ used for device %s\n", dev2->slot_name);
}
}
513 return 1;
}
516 void __init pcibios_irq_init(void)
{
DBG("PCI: IRQ init\n");
pirq_table = pirq_find_routing_table();
#ifdef CONFIG_PCI_BIOS
521 if (!pirq_table && (pci_probe & PCI_BIOS_IRQ_SCAN))
pirq_table = pcibios_get_irq_routing_table();
#endif
524 if (pirq_table) {
pirq_peer_trick();
pirq_find_router();
527 if (pirq_table->exclusive_irqs) {
int i;
529 for (i=0; i<16; i++)
530 if (!(pirq_table->exclusive_irqs & (1 << i)))
pirq_penalty[i] += 100;
}
/* If we're using the I/O APIC, avoid using the PCI IRQ routing table */
534 if (io_apic_assign_pci_irqs)
pirq_table = NULL;
}
}
539 void __init pcibios_fixup_irqs(void)
{
struct pci_dev *dev;
u8 pin;
DBG("PCI: IRQ fixup\n");
545 pci_for_each_dev(dev) {
/*
* If the BIOS has set an out of range IRQ number, just ignore it.
* Also keep track of which IRQ's are already in use.
*/
if (dev->irq >= 16) {
DBG("%s: ignoring bogus IRQ %d\n", dev->slot_name, dev->irq);
dev->irq = 0;
}
/* If the IRQ is already assigned to a PCI device, ignore its ISA use penalty */
if (pirq_penalty[dev->irq] >= 100 && pirq_penalty[dev->irq] < 100000)
pirq_penalty[dev->irq] = 0;
pirq_penalty[dev->irq]++;
}
560 pci_for_each_dev(dev) {
pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
#ifdef CONFIG_X86_IO_APIC
/*
* Recalculate IRQ numbers if we use the I/O APIC.
*/
if (io_apic_assign_pci_irqs)
{
int irq;
if (pin) {
pin--; /* interrupt pins are numbered starting from 1 */
irq = IO_APIC_get_PCI_irq_vector(dev->bus->number, PCI_SLOT(dev->devfn), pin);
/*
* Will be removed completely if things work out well with fuzzy parsing
*/
#if 0
if (irq < 0 && dev->bus->parent) { /* go back to the bridge */
struct pci_dev * bridge = dev->bus->self;
pin = (pin + PCI_SLOT(dev->devfn)) % 4;
irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
PCI_SLOT(bridge->devfn), pin);
if (irq >= 0)
printk(KERN_WARNING "PCI: using PPB(B%d,I%d,P%d) to get irq %d\n",
bridge->bus->number, PCI_SLOT(bridge->devfn), pin, irq);
}
#endif
if (irq >= 0) {
printk("PCI->APIC IRQ transform: (B%d,I%d,P%d) -> %d\n",
dev->bus->number, PCI_SLOT(dev->devfn), pin, irq);
dev->irq = irq;
}
}
}
#endif
/*
* Still no IRQ? Try to lookup one...
*/
if (pin && !dev->irq)
pcibios_lookup_irq(dev, 0);
}
}
604 void pcibios_penalize_isa_irq(int irq)
{
/*
* If any ISAPnP device reports an IRQ in its list of possible
* IRQ's, we try to avoid assigning it to PCI devices.
*/
pirq_penalty[irq] += 100;
}
613 void pcibios_enable_irq(struct pci_dev *dev)
{
u8 pin;
pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
617 if (pin && !pcibios_lookup_irq(dev, 1) && !dev->irq) {
char *msg;
619 if (io_apic_assign_pci_irqs)
msg = " Probably buggy MP table.";
621 else if (pci_probe & PCI_BIOS_IRQ_SCAN)
msg = "";
623 else
msg = " Please try using pci=biosirq.";
printk(KERN_WARNING "PCI: No IRQ known for interrupt pin %c of device %s.%s\n",
'A' + pin - 1, dev->slot_name, msg);
}
}