xref: /openbmc/linux/arch/x86/pci/irq.c (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
1 /*
2  *	Low-Level PCI Support for PC -- Routing of Interrupts
3  *
4  *	(c) 1999--2000 Martin Mares <mj@ucw.cz>
5  */
6 
7 #include <linux/types.h>
8 #include <linux/kernel.h>
9 #include <linux/pci.h>
10 #include <linux/init.h>
11 #include <linux/slab.h>
12 #include <linux/interrupt.h>
13 #include <linux/dmi.h>
14 #include <linux/io.h>
15 #include <linux/smp.h>
16 #include <asm/io_apic.h>
17 #include <linux/irq.h>
18 #include <linux/acpi.h>
19 
20 #include "pci.h"
21 
22 #define PIRQ_SIGNATURE	(('$' << 0) + ('P' << 8) + ('I' << 16) + ('R' << 24))
23 #define PIRQ_VERSION 0x0100
24 
25 static int broken_hp_bios_irq9;
26 static int acer_tm360_irqrouting;
27 
28 static struct irq_routing_table *pirq_table;
29 
30 static int pirq_enable_irq(struct pci_dev *dev);
31 
32 /*
33  * Never use: 0, 1, 2 (timer, keyboard, and cascade)
34  * Avoid using: 13, 14 and 15 (FP error and IDE).
35  * Penalize: 3, 4, 6, 7, 12 (known ISA uses: serial, floppy, parallel and mouse)
36  */
37 unsigned int pcibios_irq_mask = 0xfff8;
38 
39 static int pirq_penalty[16] = {
40 	1000000, 1000000, 1000000, 1000, 1000, 0, 1000, 1000,
41 	0, 0, 0, 0, 1000, 100000, 100000, 100000
42 };
43 
44 struct irq_router {
45 	char *name;
46 	u16 vendor, device;
47 	int (*get)(struct pci_dev *router, struct pci_dev *dev, int pirq);
48 	int (*set)(struct pci_dev *router, struct pci_dev *dev, int pirq,
49 		int new);
50 };
51 
52 struct irq_router_handler {
53 	u16 vendor;
54 	int (*probe)(struct irq_router *r, struct pci_dev *router, u16 device);
55 };
56 
57 int (*pcibios_enable_irq)(struct pci_dev *dev) = NULL;
58 void (*pcibios_disable_irq)(struct pci_dev *dev) = NULL;
59 
60 /*
61  *  Check passed address for the PCI IRQ Routing Table signature
62  *  and perform checksum verification.
63  */
64 
65 static inline struct irq_routing_table *pirq_check_routing_table(u8 *addr)
66 {
67 	struct irq_routing_table *rt;
68 	int i;
69 	u8 sum;
70 
71 	rt = (struct irq_routing_table *) addr;
72 	if (rt->signature != PIRQ_SIGNATURE ||
73 	    rt->version != PIRQ_VERSION ||
74 	    rt->size % 16 ||
75 	    rt->size < sizeof(struct irq_routing_table))
76 		return NULL;
77 	sum = 0;
78 	for (i = 0; i < rt->size; i++)
79 		sum += addr[i];
80 	if (!sum) {
81 		DBG(KERN_DEBUG "PCI: Interrupt Routing Table found at 0x%p\n",
82 			rt);
83 		return rt;
84 	}
85 	return NULL;
86 }
87 
88 
89 
90 /*
91  *  Search 0xf0000 -- 0xfffff for the PCI IRQ Routing Table.
92  */
93 
94 static struct irq_routing_table * __init pirq_find_routing_table(void)
95 {
96 	u8 *addr;
97 	struct irq_routing_table *rt;
98 
99 	if (pirq_table_addr) {
100 		rt = pirq_check_routing_table((u8 *) __va(pirq_table_addr));
101 		if (rt)
102 			return rt;
103 		printk(KERN_WARNING "PCI: PIRQ table NOT found at pirqaddr\n");
104 	}
105 	for (addr = (u8 *) __va(0xf0000); addr < (u8 *) __va(0x100000); addr += 16) {
106 		rt = pirq_check_routing_table(addr);
107 		if (rt)
108 			return rt;
109 	}
110 	return NULL;
111 }
112 
113 /*
114  *  If we have a IRQ routing table, use it to search for peer host
115  *  bridges.  It's a gross hack, but since there are no other known
116  *  ways how to get a list of buses, we have to go this way.
117  */
118 
119 static void __init pirq_peer_trick(void)
120 {
121 	struct irq_routing_table *rt = pirq_table;
122 	u8 busmap[256];
123 	int i;
124 	struct irq_info *e;
125 
126 	memset(busmap, 0, sizeof(busmap));
127 	for (i = 0; i < (rt->size - sizeof(struct irq_routing_table)) / sizeof(struct irq_info); i++) {
128 		e = &rt->slots[i];
129 #ifdef DEBUG
130 		{
131 			int j;
132 			DBG(KERN_DEBUG "%02x:%02x slot=%02x", e->bus, e->devfn/8, e->slot);
133 			for (j = 0; j < 4; j++)
134 				DBG(" %d:%02x/%04x", j, e->irq[j].link, e->irq[j].bitmap);
135 			DBG("\n");
136 		}
137 #endif
138 		busmap[e->bus] = 1;
139 	}
140 	for (i = 1; i < 256; i++) {
141 		int node;
142 		if (!busmap[i] || pci_find_bus(0, i))
143 			continue;
144 		node = get_mp_bus_to_node(i);
145 		if (pci_scan_bus_on_node(i, &pci_root_ops, node))
146 			printk(KERN_INFO "PCI: Discovered primary peer "
147 			       "bus %02x [IRQ]\n", i);
148 	}
149 	pcibios_last_bus = -1;
150 }
151 
152 /*
153  *  Code for querying and setting of IRQ routes on various interrupt routers.
154  */
155 
156 void eisa_set_level_irq(unsigned int irq)
157 {
158 	unsigned char mask = 1 << (irq & 7);
159 	unsigned int port = 0x4d0 + (irq >> 3);
160 	unsigned char val;
161 	static u16 eisa_irq_mask;
162 
163 	if (irq >= 16 || (1 << irq) & eisa_irq_mask)
164 		return;
165 
166 	eisa_irq_mask |= (1 << irq);
167 	printk(KERN_DEBUG "PCI: setting IRQ %u as level-triggered\n", irq);
168 	val = inb(port);
169 	if (!(val & mask)) {
170 		DBG(KERN_DEBUG " -> edge");
171 		outb(val | mask, port);
172 	}
173 }
174 
175 /*
176  * Common IRQ routing practice: nibbles in config space,
177  * offset by some magic constant.
178  */
179 static unsigned int read_config_nybble(struct pci_dev *router, unsigned offset, unsigned nr)
180 {
181 	u8 x;
182 	unsigned reg = offset + (nr >> 1);
183 
184 	pci_read_config_byte(router, reg, &x);
185 	return (nr & 1) ? (x >> 4) : (x & 0xf);
186 }
187 
188 static void write_config_nybble(struct pci_dev *router, unsigned offset,
189 	unsigned nr, unsigned int val)
190 {
191 	u8 x;
192 	unsigned reg = offset + (nr >> 1);
193 
194 	pci_read_config_byte(router, reg, &x);
195 	x = (nr & 1) ? ((x & 0x0f) | (val << 4)) : ((x & 0xf0) | val);
196 	pci_write_config_byte(router, reg, x);
197 }
198 
199 /*
200  * ALI pirq entries are damn ugly, and completely undocumented.
201  * This has been figured out from pirq tables, and it's not a pretty
202  * picture.
203  */
204 static int pirq_ali_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
205 {
206 	static const unsigned char irqmap[16] = { 0, 9, 3, 10, 4, 5, 7, 6, 1, 11, 0, 12, 0, 14, 0, 15 };
207 
208 	WARN_ON_ONCE(pirq > 16);
209 	return irqmap[read_config_nybble(router, 0x48, pirq-1)];
210 }
211 
212 static int pirq_ali_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
213 {
214 	static const unsigned char irqmap[16] = { 0, 8, 0, 2, 4, 5, 7, 6, 0, 1, 3, 9, 11, 0, 13, 15 };
215 	unsigned int val = irqmap[irq];
216 
217 	WARN_ON_ONCE(pirq > 16);
218 	if (val) {
219 		write_config_nybble(router, 0x48, pirq-1, val);
220 		return 1;
221 	}
222 	return 0;
223 }
224 
225 /*
226  * The Intel PIIX4 pirq rules are fairly simple: "pirq" is
227  * just a pointer to the config space.
228  */
229 static int pirq_piix_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
230 {
231 	u8 x;
232 
233 	pci_read_config_byte(router, pirq, &x);
234 	return (x < 16) ? x : 0;
235 }
236 
237 static int pirq_piix_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
238 {
239 	pci_write_config_byte(router, pirq, irq);
240 	return 1;
241 }
242 
243 /*
244  * The VIA pirq rules are nibble-based, like ALI,
245  * but without the ugly irq number munging.
246  * However, PIRQD is in the upper instead of lower 4 bits.
247  */
248 static int pirq_via_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
249 {
250 	return read_config_nybble(router, 0x55, pirq == 4 ? 5 : pirq);
251 }
252 
253 static int pirq_via_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
254 {
255 	write_config_nybble(router, 0x55, pirq == 4 ? 5 : pirq, irq);
256 	return 1;
257 }
258 
259 /*
260  * The VIA pirq rules are nibble-based, like ALI,
261  * but without the ugly irq number munging.
262  * However, for 82C586, nibble map is different .
263  */
264 static int pirq_via586_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
265 {
266 	static const unsigned int pirqmap[5] = { 3, 2, 5, 1, 1 };
267 
268 	WARN_ON_ONCE(pirq > 5);
269 	return read_config_nybble(router, 0x55, pirqmap[pirq-1]);
270 }
271 
272 static int pirq_via586_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
273 {
274 	static const unsigned int pirqmap[5] = { 3, 2, 5, 1, 1 };
275 
276 	WARN_ON_ONCE(pirq > 5);
277 	write_config_nybble(router, 0x55, pirqmap[pirq-1], irq);
278 	return 1;
279 }
280 
281 /*
282  * ITE 8330G pirq rules are nibble-based
283  * FIXME: pirqmap may be { 1, 0, 3, 2 },
284  * 	  2+3 are both mapped to irq 9 on my system
285  */
286 static int pirq_ite_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
287 {
288 	static const unsigned char pirqmap[4] = { 1, 0, 2, 3 };
289 
290 	WARN_ON_ONCE(pirq > 4);
291 	return read_config_nybble(router, 0x43, pirqmap[pirq-1]);
292 }
293 
294 static int pirq_ite_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
295 {
296 	static const unsigned char pirqmap[4] = { 1, 0, 2, 3 };
297 
298 	WARN_ON_ONCE(pirq > 4);
299 	write_config_nybble(router, 0x43, pirqmap[pirq-1], irq);
300 	return 1;
301 }
302 
303 /*
304  * OPTI: high four bits are nibble pointer..
305  * I wonder what the low bits do?
306  */
307 static int pirq_opti_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
308 {
309 	return read_config_nybble(router, 0xb8, pirq >> 4);
310 }
311 
312 static int pirq_opti_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
313 {
314 	write_config_nybble(router, 0xb8, pirq >> 4, irq);
315 	return 1;
316 }
317 
318 /*
319  * Cyrix: nibble offset 0x5C
320  * 0x5C bits 7:4 is INTB bits 3:0 is INTA
321  * 0x5D bits 7:4 is INTD bits 3:0 is INTC
322  */
323 static int pirq_cyrix_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
324 {
325 	return read_config_nybble(router, 0x5C, (pirq-1)^1);
326 }
327 
328 static int pirq_cyrix_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
329 {
330 	write_config_nybble(router, 0x5C, (pirq-1)^1, irq);
331 	return 1;
332 }
333 
334 /*
335  *	PIRQ routing for SiS 85C503 router used in several SiS chipsets.
336  *	We have to deal with the following issues here:
337  *	- vendors have different ideas about the meaning of link values
338  *	- some onboard devices (integrated in the chipset) have special
339  *	  links and are thus routed differently (i.e. not via PCI INTA-INTD)
340  *	- different revision of the router have a different layout for
341  *	  the routing registers, particularly for the onchip devices
342  *
343  *	For all routing registers the common thing is we have one byte
344  *	per routeable link which is defined as:
345  *		 bit 7      IRQ mapping enabled (0) or disabled (1)
346  *		 bits [6:4] reserved (sometimes used for onchip devices)
347  *		 bits [3:0] IRQ to map to
348  *		     allowed: 3-7, 9-12, 14-15
349  *		     reserved: 0, 1, 2, 8, 13
350  *
351  *	The config-space registers located at 0x41/0x42/0x43/0x44 are
352  *	always used to route the normal PCI INT A/B/C/D respectively.
353  *	Apparently there are systems implementing PCI routing table using
354  *	link values 0x01-0x04 and others using 0x41-0x44 for PCI INTA..D.
355  *	We try our best to handle both link mappings.
356  *
357  *	Currently (2003-05-21) it appears most SiS chipsets follow the
358  *	definition of routing registers from the SiS-5595 southbridge.
359  *	According to the SiS 5595 datasheets the revision id's of the
360  *	router (ISA-bridge) should be 0x01 or 0xb0.
361  *
362  *	Furthermore we've also seen lspci dumps with revision 0x00 and 0xb1.
363  *	Looks like these are used in a number of SiS 5xx/6xx/7xx chipsets.
364  *	They seem to work with the current routing code. However there is
365  *	some concern because of the two USB-OHCI HCs (original SiS 5595
366  *	had only one). YMMV.
367  *
368  *	Onchip routing for router rev-id 0x01/0xb0 and probably 0x00/0xb1:
369  *
370  *	0x61:	IDEIRQ:
371  *		bits [6:5] must be written 01
372  *		bit 4 channel-select primary (0), secondary (1)
373  *
374  *	0x62:	USBIRQ:
375  *		bit 6 OHCI function disabled (0), enabled (1)
376  *
377  *	0x6a:	ACPI/SCI IRQ: bits 4-6 reserved
378  *
379  *	0x7e:	Data Acq. Module IRQ - bits 4-6 reserved
380  *
381  *	We support USBIRQ (in addition to INTA-INTD) and keep the
382  *	IDE, ACPI and DAQ routing untouched as set by the BIOS.
383  *
384  *	Currently the only reported exception is the new SiS 65x chipset
385  *	which includes the SiS 69x southbridge. Here we have the 85C503
386  *	router revision 0x04 and there are changes in the register layout
387  *	mostly related to the different USB HCs with USB 2.0 support.
388  *
389  *	Onchip routing for router rev-id 0x04 (try-and-error observation)
390  *
391  *	0x60/0x61/0x62/0x63:	1xEHCI and 3xOHCI (companion) USB-HCs
392  *				bit 6-4 are probably unused, not like 5595
393  */
394 
395 #define PIRQ_SIS_IRQ_MASK	0x0f
396 #define PIRQ_SIS_IRQ_DISABLE	0x80
397 #define PIRQ_SIS_USB_ENABLE	0x40
398 
399 static int pirq_sis_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
400 {
401 	u8 x;
402 	int reg;
403 
404 	reg = pirq;
405 	if (reg >= 0x01 && reg <= 0x04)
406 		reg += 0x40;
407 	pci_read_config_byte(router, reg, &x);
408 	return (x & PIRQ_SIS_IRQ_DISABLE) ? 0 : (x & PIRQ_SIS_IRQ_MASK);
409 }
410 
411 static int pirq_sis_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
412 {
413 	u8 x;
414 	int reg;
415 
416 	reg = pirq;
417 	if (reg >= 0x01 && reg <= 0x04)
418 		reg += 0x40;
419 	pci_read_config_byte(router, reg, &x);
420 	x &= ~(PIRQ_SIS_IRQ_MASK | PIRQ_SIS_IRQ_DISABLE);
421 	x |= irq ? irq: PIRQ_SIS_IRQ_DISABLE;
422 	pci_write_config_byte(router, reg, x);
423 	return 1;
424 }
425 
426 
427 /*
428  * VLSI: nibble offset 0x74 - educated guess due to routing table and
429  *       config space of VLSI 82C534 PCI-bridge/router (1004:0102)
430  *       Tested on HP OmniBook 800 covering PIRQ 1, 2, 4, 8 for onboard
431  *       devices, PIRQ 3 for non-pci(!) soundchip and (untested) PIRQ 6
432  *       for the busbridge to the docking station.
433  */
434 
435 static int pirq_vlsi_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
436 {
437 	WARN_ON_ONCE(pirq >= 9);
438 	if (pirq > 8) {
439 		printk(KERN_INFO "VLSI router pirq escape (%d)\n", pirq);
440 		return 0;
441 	}
442 	return read_config_nybble(router, 0x74, pirq-1);
443 }
444 
445 static int pirq_vlsi_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
446 {
447 	WARN_ON_ONCE(pirq >= 9);
448 	if (pirq > 8) {
449 		printk(KERN_INFO "VLSI router pirq escape (%d)\n", pirq);
450 		return 0;
451 	}
452 	write_config_nybble(router, 0x74, pirq-1, irq);
453 	return 1;
454 }
455 
456 /*
457  * ServerWorks: PCI interrupts mapped to system IRQ lines through Index
458  * and Redirect I/O registers (0x0c00 and 0x0c01).  The Index register
459  * format is (PCIIRQ## | 0x10), e.g.: PCIIRQ10=0x1a.  The Redirect
460  * register is a straight binary coding of desired PIC IRQ (low nibble).
461  *
462  * The 'link' value in the PIRQ table is already in the correct format
463  * for the Index register.  There are some special index values:
464  * 0x00 for ACPI (SCI), 0x01 for USB, 0x02 for IDE0, 0x04 for IDE1,
465  * and 0x03 for SMBus.
466  */
467 static int pirq_serverworks_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
468 {
469 	outb(pirq, 0xc00);
470 	return inb(0xc01) & 0xf;
471 }
472 
473 static int pirq_serverworks_set(struct pci_dev *router, struct pci_dev *dev,
474 	int pirq, int irq)
475 {
476 	outb(pirq, 0xc00);
477 	outb(irq, 0xc01);
478 	return 1;
479 }
480 
481 /* Support for AMD756 PCI IRQ Routing
482  * Jhon H. Caicedo <jhcaiced@osso.org.co>
483  * Jun/21/2001 0.2.0 Release, fixed to use "nybble" functions... (jhcaiced)
484  * Jun/19/2001 Alpha Release 0.1.0 (jhcaiced)
485  * The AMD756 pirq rules are nibble-based
486  * offset 0x56 0-3 PIRQA  4-7  PIRQB
487  * offset 0x57 0-3 PIRQC  4-7  PIRQD
488  */
489 static int pirq_amd756_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
490 {
491 	u8 irq;
492 	irq = 0;
493 	if (pirq <= 4)
494 		irq = read_config_nybble(router, 0x56, pirq - 1);
495 	printk(KERN_INFO "AMD756: dev %04x:%04x, router pirq : %d get irq : %2d\n",
496 		dev->vendor, dev->device, pirq, irq);
497 	return irq;
498 }
499 
500 static int pirq_amd756_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
501 {
502 	printk(KERN_INFO "AMD756: dev %04x:%04x, router pirq : %d SET irq : %2d\n",
503 		dev->vendor, dev->device, pirq, irq);
504 	if (pirq <= 4)
505 		write_config_nybble(router, 0x56, pirq - 1, irq);
506 	return 1;
507 }
508 
509 /*
510  * PicoPower PT86C523
511  */
512 static int pirq_pico_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
513 {
514 	outb(0x10 + ((pirq - 1) >> 1), 0x24);
515 	return ((pirq - 1) & 1) ? (inb(0x26) >> 4) : (inb(0x26) & 0xf);
516 }
517 
518 static int pirq_pico_set(struct pci_dev *router, struct pci_dev *dev, int pirq,
519 			int irq)
520 {
521 	unsigned int x;
522 	outb(0x10 + ((pirq - 1) >> 1), 0x24);
523 	x = inb(0x26);
524 	x = ((pirq - 1) & 1) ? ((x & 0x0f) | (irq << 4)) : ((x & 0xf0) | (irq));
525 	outb(x, 0x26);
526 	return 1;
527 }
528 
529 #ifdef CONFIG_PCI_BIOS
530 
531 static int pirq_bios_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
532 {
533 	struct pci_dev *bridge;
534 	int pin = pci_get_interrupt_pin(dev, &bridge);
535 	return pcibios_set_irq_routing(bridge, pin, irq);
536 }
537 
538 #endif
539 
540 static __init int intel_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
541 {
542 	static struct pci_device_id __initdata pirq_440gx[] = {
543 		{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_0) },
544 		{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_2) },
545 		{ },
546 	};
547 
548 	/* 440GX has a proprietary PIRQ router -- don't use it */
549 	if (pci_dev_present(pirq_440gx))
550 		return 0;
551 
552 	switch (device) {
553 	case PCI_DEVICE_ID_INTEL_82371FB_0:
554 	case PCI_DEVICE_ID_INTEL_82371SB_0:
555 	case PCI_DEVICE_ID_INTEL_82371AB_0:
556 	case PCI_DEVICE_ID_INTEL_82371MX:
557 	case PCI_DEVICE_ID_INTEL_82443MX_0:
558 	case PCI_DEVICE_ID_INTEL_82801AA_0:
559 	case PCI_DEVICE_ID_INTEL_82801AB_0:
560 	case PCI_DEVICE_ID_INTEL_82801BA_0:
561 	case PCI_DEVICE_ID_INTEL_82801BA_10:
562 	case PCI_DEVICE_ID_INTEL_82801CA_0:
563 	case PCI_DEVICE_ID_INTEL_82801CA_12:
564 	case PCI_DEVICE_ID_INTEL_82801DB_0:
565 	case PCI_DEVICE_ID_INTEL_82801E_0:
566 	case PCI_DEVICE_ID_INTEL_82801EB_0:
567 	case PCI_DEVICE_ID_INTEL_ESB_1:
568 	case PCI_DEVICE_ID_INTEL_ICH6_0:
569 	case PCI_DEVICE_ID_INTEL_ICH6_1:
570 	case PCI_DEVICE_ID_INTEL_ICH7_0:
571 	case PCI_DEVICE_ID_INTEL_ICH7_1:
572 	case PCI_DEVICE_ID_INTEL_ICH7_30:
573 	case PCI_DEVICE_ID_INTEL_ICH7_31:
574 	case PCI_DEVICE_ID_INTEL_ESB2_0:
575 	case PCI_DEVICE_ID_INTEL_ICH8_0:
576 	case PCI_DEVICE_ID_INTEL_ICH8_1:
577 	case PCI_DEVICE_ID_INTEL_ICH8_2:
578 	case PCI_DEVICE_ID_INTEL_ICH8_3:
579 	case PCI_DEVICE_ID_INTEL_ICH8_4:
580 	case PCI_DEVICE_ID_INTEL_ICH9_0:
581 	case PCI_DEVICE_ID_INTEL_ICH9_1:
582 	case PCI_DEVICE_ID_INTEL_ICH9_2:
583 	case PCI_DEVICE_ID_INTEL_ICH9_3:
584 	case PCI_DEVICE_ID_INTEL_ICH9_4:
585 	case PCI_DEVICE_ID_INTEL_ICH9_5:
586 	case PCI_DEVICE_ID_INTEL_TOLAPAI_0:
587 	case PCI_DEVICE_ID_INTEL_ICH10_0:
588 	case PCI_DEVICE_ID_INTEL_ICH10_1:
589 	case PCI_DEVICE_ID_INTEL_ICH10_2:
590 	case PCI_DEVICE_ID_INTEL_ICH10_3:
591 		r->name = "PIIX/ICH";
592 		r->get = pirq_piix_get;
593 		r->set = pirq_piix_set;
594 		return 1;
595 	}
596 	return 0;
597 }
598 
599 static __init int via_router_probe(struct irq_router *r,
600 				struct pci_dev *router, u16 device)
601 {
602 	/* FIXME: We should move some of the quirk fixup stuff here */
603 
604 	/*
605 	 * workarounds for some buggy BIOSes
606 	 */
607 	if (device == PCI_DEVICE_ID_VIA_82C586_0) {
608 		switch (router->device) {
609 		case PCI_DEVICE_ID_VIA_82C686:
610 			/*
611 			 * Asus k7m bios wrongly reports 82C686A
612 			 * as 586-compatible
613 			 */
614 			device = PCI_DEVICE_ID_VIA_82C686;
615 			break;
616 		case PCI_DEVICE_ID_VIA_8235:
617 			/**
618 			 * Asus a7v-x bios wrongly reports 8235
619 			 * as 586-compatible
620 			 */
621 			device = PCI_DEVICE_ID_VIA_8235;
622 			break;
623 		case PCI_DEVICE_ID_VIA_8237:
624 			/**
625 			 * Asus a7v600 bios wrongly reports 8237
626 			 * as 586-compatible
627 			 */
628 			device = PCI_DEVICE_ID_VIA_8237;
629 			break;
630 		}
631 	}
632 
633 	switch (device) {
634 	case PCI_DEVICE_ID_VIA_82C586_0:
635 		r->name = "VIA";
636 		r->get = pirq_via586_get;
637 		r->set = pirq_via586_set;
638 		return 1;
639 	case PCI_DEVICE_ID_VIA_82C596:
640 	case PCI_DEVICE_ID_VIA_82C686:
641 	case PCI_DEVICE_ID_VIA_8231:
642 	case PCI_DEVICE_ID_VIA_8233A:
643 	case PCI_DEVICE_ID_VIA_8235:
644 	case PCI_DEVICE_ID_VIA_8237:
645 		/* FIXME: add new ones for 8233/5 */
646 		r->name = "VIA";
647 		r->get = pirq_via_get;
648 		r->set = pirq_via_set;
649 		return 1;
650 	}
651 	return 0;
652 }
653 
654 static __init int vlsi_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
655 {
656 	switch (device) {
657 	case PCI_DEVICE_ID_VLSI_82C534:
658 		r->name = "VLSI 82C534";
659 		r->get = pirq_vlsi_get;
660 		r->set = pirq_vlsi_set;
661 		return 1;
662 	}
663 	return 0;
664 }
665 
666 
667 static __init int serverworks_router_probe(struct irq_router *r,
668 		struct pci_dev *router, u16 device)
669 {
670 	switch (device) {
671 	case PCI_DEVICE_ID_SERVERWORKS_OSB4:
672 	case PCI_DEVICE_ID_SERVERWORKS_CSB5:
673 		r->name = "ServerWorks";
674 		r->get = pirq_serverworks_get;
675 		r->set = pirq_serverworks_set;
676 		return 1;
677 	}
678 	return 0;
679 }
680 
681 static __init int sis_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
682 {
683 	if (device != PCI_DEVICE_ID_SI_503)
684 		return 0;
685 
686 	r->name = "SIS";
687 	r->get = pirq_sis_get;
688 	r->set = pirq_sis_set;
689 	return 1;
690 }
691 
692 static __init int cyrix_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
693 {
694 	switch (device) {
695 	case PCI_DEVICE_ID_CYRIX_5520:
696 		r->name = "NatSemi";
697 		r->get = pirq_cyrix_get;
698 		r->set = pirq_cyrix_set;
699 		return 1;
700 	}
701 	return 0;
702 }
703 
704 static __init int opti_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
705 {
706 	switch (device) {
707 	case PCI_DEVICE_ID_OPTI_82C700:
708 		r->name = "OPTI";
709 		r->get = pirq_opti_get;
710 		r->set = pirq_opti_set;
711 		return 1;
712 	}
713 	return 0;
714 }
715 
716 static __init int ite_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
717 {
718 	switch (device) {
719 	case PCI_DEVICE_ID_ITE_IT8330G_0:
720 		r->name = "ITE";
721 		r->get = pirq_ite_get;
722 		r->set = pirq_ite_set;
723 		return 1;
724 	}
725 	return 0;
726 }
727 
728 static __init int ali_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
729 {
730 	switch (device) {
731 	case PCI_DEVICE_ID_AL_M1533:
732 	case PCI_DEVICE_ID_AL_M1563:
733 		printk(KERN_DEBUG "PCI: Using ALI IRQ Router\n");
734 		r->name = "ALI";
735 		r->get = pirq_ali_get;
736 		r->set = pirq_ali_set;
737 		return 1;
738 	}
739 	return 0;
740 }
741 
742 static __init int amd_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
743 {
744 	switch (device) {
745 	case PCI_DEVICE_ID_AMD_VIPER_740B:
746 		r->name = "AMD756";
747 		break;
748 	case PCI_DEVICE_ID_AMD_VIPER_7413:
749 		r->name = "AMD766";
750 		break;
751 	case PCI_DEVICE_ID_AMD_VIPER_7443:
752 		r->name = "AMD768";
753 		break;
754 	default:
755 		return 0;
756 	}
757 	r->get = pirq_amd756_get;
758 	r->set = pirq_amd756_set;
759 	return 1;
760 }
761 
762 static __init int pico_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
763 {
764 	switch (device) {
765 	case PCI_DEVICE_ID_PICOPOWER_PT86C523:
766 		r->name = "PicoPower PT86C523";
767 		r->get = pirq_pico_get;
768 		r->set = pirq_pico_set;
769 		return 1;
770 
771 	case PCI_DEVICE_ID_PICOPOWER_PT86C523BBP:
772 		r->name = "PicoPower PT86C523 rev. BB+";
773 		r->get = pirq_pico_get;
774 		r->set = pirq_pico_set;
775 		return 1;
776 	}
777 	return 0;
778 }
779 
780 static __initdata struct irq_router_handler pirq_routers[] = {
781 	{ PCI_VENDOR_ID_INTEL, intel_router_probe },
782 	{ PCI_VENDOR_ID_AL, ali_router_probe },
783 	{ PCI_VENDOR_ID_ITE, ite_router_probe },
784 	{ PCI_VENDOR_ID_VIA, via_router_probe },
785 	{ PCI_VENDOR_ID_OPTI, opti_router_probe },
786 	{ PCI_VENDOR_ID_SI, sis_router_probe },
787 	{ PCI_VENDOR_ID_CYRIX, cyrix_router_probe },
788 	{ PCI_VENDOR_ID_VLSI, vlsi_router_probe },
789 	{ PCI_VENDOR_ID_SERVERWORKS, serverworks_router_probe },
790 	{ PCI_VENDOR_ID_AMD, amd_router_probe },
791 	{ PCI_VENDOR_ID_PICOPOWER, pico_router_probe },
792 	/* Someone with docs needs to add the ATI Radeon IGP */
793 	{ 0, NULL }
794 };
795 static struct irq_router pirq_router;
796 static struct pci_dev *pirq_router_dev;
797 
798 
799 /*
800  *	FIXME: should we have an option to say "generic for
801  *	chipset" ?
802  */
803 
804 static void __init pirq_find_router(struct irq_router *r)
805 {
806 	struct irq_routing_table *rt = pirq_table;
807 	struct irq_router_handler *h;
808 
809 #ifdef CONFIG_PCI_BIOS
810 	if (!rt->signature) {
811 		printk(KERN_INFO "PCI: Using BIOS for IRQ routing\n");
812 		r->set = pirq_bios_set;
813 		r->name = "BIOS";
814 		return;
815 	}
816 #endif
817 
818 	/* Default unless a driver reloads it */
819 	r->name = "default";
820 	r->get = NULL;
821 	r->set = NULL;
822 
823 	DBG(KERN_DEBUG "PCI: Attempting to find IRQ router for %04x:%04x\n",
824 	    rt->rtr_vendor, rt->rtr_device);
825 
826 	pirq_router_dev = pci_get_bus_and_slot(rt->rtr_bus, rt->rtr_devfn);
827 	if (!pirq_router_dev) {
828 		DBG(KERN_DEBUG "PCI: Interrupt router not found at "
829 			"%02x:%02x\n", rt->rtr_bus, rt->rtr_devfn);
830 		return;
831 	}
832 
833 	for (h = pirq_routers; h->vendor; h++) {
834 		/* First look for a router match */
835 		if (rt->rtr_vendor == h->vendor &&
836 			h->probe(r, pirq_router_dev, rt->rtr_device))
837 			break;
838 		/* Fall back to a device match */
839 		if (pirq_router_dev->vendor == h->vendor &&
840 			h->probe(r, pirq_router_dev, pirq_router_dev->device))
841 			break;
842 	}
843 	printk(KERN_INFO "PCI: Using IRQ router %s [%04x/%04x] at %s\n",
844 		pirq_router.name,
845 		pirq_router_dev->vendor,
846 		pirq_router_dev->device,
847 		pci_name(pirq_router_dev));
848 
849 	/* The device remains referenced for the kernel lifetime */
850 }
851 
852 static struct irq_info *pirq_get_info(struct pci_dev *dev)
853 {
854 	struct irq_routing_table *rt = pirq_table;
855 	int entries = (rt->size - sizeof(struct irq_routing_table)) /
856 		sizeof(struct irq_info);
857 	struct irq_info *info;
858 
859 	for (info = rt->slots; entries--; info++)
860 		if (info->bus == dev->bus->number &&
861 			PCI_SLOT(info->devfn) == PCI_SLOT(dev->devfn))
862 			return info;
863 	return NULL;
864 }
865 
866 static int pcibios_lookup_irq(struct pci_dev *dev, int assign)
867 {
868 	u8 pin;
869 	struct irq_info *info;
870 	int i, pirq, newirq;
871 	int irq = 0;
872 	u32 mask;
873 	struct irq_router *r = &pirq_router;
874 	struct pci_dev *dev2 = NULL;
875 	char *msg = NULL;
876 
877 	/* Find IRQ pin */
878 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
879 	if (!pin) {
880 		DBG(KERN_DEBUG " -> no interrupt pin\n");
881 		return 0;
882 	}
883 	pin = pin - 1;
884 
885 	/* Find IRQ routing entry */
886 
887 	if (!pirq_table)
888 		return 0;
889 
890 	DBG(KERN_DEBUG "IRQ for %s[%c]", pci_name(dev), 'A' + pin);
891 	info = pirq_get_info(dev);
892 	if (!info) {
893 		DBG(" -> not found in routing table\n" KERN_DEBUG);
894 		return 0;
895 	}
896 	pirq = info->irq[pin].link;
897 	mask = info->irq[pin].bitmap;
898 	if (!pirq) {
899 		DBG(" -> not routed\n" KERN_DEBUG);
900 		return 0;
901 	}
902 	DBG(" -> PIRQ %02x, mask %04x, excl %04x", pirq, mask,
903 		pirq_table->exclusive_irqs);
904 	mask &= pcibios_irq_mask;
905 
906 	/* Work around broken HP Pavilion Notebooks which assign USB to
907 	   IRQ 9 even though it is actually wired to IRQ 11 */
908 
909 	if (broken_hp_bios_irq9 && pirq == 0x59 && dev->irq == 9) {
910 		dev->irq = 11;
911 		pci_write_config_byte(dev, PCI_INTERRUPT_LINE, 11);
912 		r->set(pirq_router_dev, dev, pirq, 11);
913 	}
914 
915 	/* same for Acer Travelmate 360, but with CB and irq 11 -> 10 */
916 	if (acer_tm360_irqrouting && dev->irq == 11 &&
917 		dev->vendor == PCI_VENDOR_ID_O2) {
918 		pirq = 0x68;
919 		mask = 0x400;
920 		dev->irq = r->get(pirq_router_dev, dev, pirq);
921 		pci_write_config_byte(dev, PCI_INTERRUPT_LINE, dev->irq);
922 	}
923 
924 	/*
925 	 * Find the best IRQ to assign: use the one
926 	 * reported by the device if possible.
927 	 */
928 	newirq = dev->irq;
929 	if (newirq && !((1 << newirq) & mask)) {
930 		if (pci_probe & PCI_USE_PIRQ_MASK)
931 			newirq = 0;
932 		else
933 			printk("\n" KERN_WARNING
934 				"PCI: IRQ %i for device %s doesn't match PIRQ mask - try pci=usepirqmask\n"
935 				KERN_DEBUG, newirq,
936 				pci_name(dev));
937 	}
938 	if (!newirq && assign) {
939 		for (i = 0; i < 16; i++) {
940 			if (!(mask & (1 << i)))
941 				continue;
942 			if (pirq_penalty[i] < pirq_penalty[newirq] &&
943 				can_request_irq(i, IRQF_SHARED))
944 				newirq = i;
945 		}
946 	}
947 	DBG(" -> newirq=%d", newirq);
948 
949 	/* Check if it is hardcoded */
950 	if ((pirq & 0xf0) == 0xf0) {
951 		irq = pirq & 0xf;
952 		DBG(" -> hardcoded IRQ %d\n", irq);
953 		msg = "Hardcoded";
954 	} else if (r->get && (irq = r->get(pirq_router_dev, dev, pirq)) && \
955 	((!(pci_probe & PCI_USE_PIRQ_MASK)) || ((1 << irq) & mask))) {
956 		DBG(" -> got IRQ %d\n", irq);
957 		msg = "Found";
958 		eisa_set_level_irq(irq);
959 	} else if (newirq && r->set &&
960 		(dev->class >> 8) != PCI_CLASS_DISPLAY_VGA) {
961 		DBG(" -> assigning IRQ %d", newirq);
962 		if (r->set(pirq_router_dev, dev, pirq, newirq)) {
963 			eisa_set_level_irq(newirq);
964 			DBG(" ... OK\n");
965 			msg = "Assigned";
966 			irq = newirq;
967 		}
968 	}
969 
970 	if (!irq) {
971 		DBG(" ... failed\n");
972 		if (newirq && mask == (1 << newirq)) {
973 			msg = "Guessed";
974 			irq = newirq;
975 		} else
976 			return 0;
977 	}
978 	printk(KERN_INFO "PCI: %s IRQ %d for device %s\n", msg, irq,
979 		pci_name(dev));
980 
981 	/* Update IRQ for all devices with the same pirq value */
982 	while ((dev2 = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev2)) != NULL) {
983 		pci_read_config_byte(dev2, PCI_INTERRUPT_PIN, &pin);
984 		if (!pin)
985 			continue;
986 		pin--;
987 		info = pirq_get_info(dev2);
988 		if (!info)
989 			continue;
990 		if (info->irq[pin].link == pirq) {
991 			/*
992 			 * We refuse to override the dev->irq
993 			 * information. Give a warning!
994 			 */
995 			if (dev2->irq && dev2->irq != irq && \
996 			(!(pci_probe & PCI_USE_PIRQ_MASK) || \
997 			((1 << dev2->irq) & mask))) {
998 #ifndef CONFIG_PCI_MSI
999 				printk(KERN_INFO "IRQ routing conflict for %s, have irq %d, want irq %d\n",
1000 				       pci_name(dev2), dev2->irq, irq);
1001 #endif
1002 				continue;
1003 			}
1004 			dev2->irq = irq;
1005 			pirq_penalty[irq]++;
1006 			if (dev != dev2)
1007 				printk(KERN_INFO
1008 					"PCI: Sharing IRQ %d with %s\n",
1009 					irq, pci_name(dev2));
1010 		}
1011 	}
1012 	return 1;
1013 }
1014 
1015 static void __init pcibios_fixup_irqs(void)
1016 {
1017 	struct pci_dev *dev = NULL;
1018 	u8 pin;
1019 
1020 	DBG(KERN_DEBUG "PCI: IRQ fixup\n");
1021 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
1022 		/*
1023 		 * If the BIOS has set an out of range IRQ number, just
1024 		 * ignore it.  Also keep track of which IRQ's are
1025 		 * already in use.
1026 		 */
1027 		if (dev->irq >= 16) {
1028 			DBG(KERN_DEBUG "%s: ignoring bogus IRQ %d\n",
1029 				pci_name(dev), dev->irq);
1030 			dev->irq = 0;
1031 		}
1032 		/*
1033 		 * If the IRQ is already assigned to a PCI device,
1034 		 * ignore its ISA use penalty
1035 		 */
1036 		if (pirq_penalty[dev->irq] >= 100 &&
1037 				pirq_penalty[dev->irq] < 100000)
1038 			pirq_penalty[dev->irq] = 0;
1039 		pirq_penalty[dev->irq]++;
1040 	}
1041 
1042 	dev = NULL;
1043 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
1044 		pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
1045 #ifdef CONFIG_X86_IO_APIC
1046 		/*
1047 		 * Recalculate IRQ numbers if we use the I/O APIC.
1048 		 */
1049 		if (io_apic_assign_pci_irqs) {
1050 			int irq;
1051 
1052 			if (pin) {
1053 				/*
1054 				 * interrupt pins are numbered starting
1055 				 * from 1
1056 				 */
1057 				pin--;
1058 				irq = IO_APIC_get_PCI_irq_vector(dev->bus->number,
1059 					PCI_SLOT(dev->devfn), pin);
1060 	/*
1061 	 * Busses behind bridges are typically not listed in the MP-table.
1062 	 * In this case we have to look up the IRQ based on the parent bus,
1063 	 * parent slot, and pin number. The SMP code detects such bridged
1064 	 * busses itself so we should get into this branch reliably.
1065 	 */
1066 				if (irq < 0 && dev->bus->parent) { /* go back to the bridge */
1067 					struct pci_dev *bridge = dev->bus->self;
1068 
1069 					pin = (pin + PCI_SLOT(dev->devfn)) % 4;
1070 					irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
1071 							PCI_SLOT(bridge->devfn), pin);
1072 					if (irq >= 0)
1073 						printk(KERN_WARNING "PCI: using PPB %s[%c] to get irq %d\n",
1074 							pci_name(bridge), 'A' + pin, irq);
1075 				}
1076 				if (irq >= 0) {
1077 					printk(KERN_INFO "PCI->APIC IRQ transform: %s[%c] -> IRQ %d\n",
1078 						pci_name(dev), 'A' + pin, irq);
1079 					dev->irq = irq;
1080 				}
1081 			}
1082 		}
1083 #endif
1084 		/*
1085 		 * Still no IRQ? Try to lookup one...
1086 		 */
1087 		if (pin && !dev->irq)
1088 			pcibios_lookup_irq(dev, 0);
1089 	}
1090 }
1091 
1092 /*
1093  * Work around broken HP Pavilion Notebooks which assign USB to
1094  * IRQ 9 even though it is actually wired to IRQ 11
1095  */
1096 static int __init fix_broken_hp_bios_irq9(const struct dmi_system_id *d)
1097 {
1098 	if (!broken_hp_bios_irq9) {
1099 		broken_hp_bios_irq9 = 1;
1100 		printk(KERN_INFO "%s detected - fixing broken IRQ routing\n",
1101 			d->ident);
1102 	}
1103 	return 0;
1104 }
1105 
1106 /*
1107  * Work around broken Acer TravelMate 360 Notebooks which assign
1108  * Cardbus to IRQ 11 even though it is actually wired to IRQ 10
1109  */
1110 static int __init fix_acer_tm360_irqrouting(const struct dmi_system_id *d)
1111 {
1112 	if (!acer_tm360_irqrouting) {
1113 		acer_tm360_irqrouting = 1;
1114 		printk(KERN_INFO "%s detected - fixing broken IRQ routing\n",
1115 			d->ident);
1116 	}
1117 	return 0;
1118 }
1119 
1120 static struct dmi_system_id __initdata pciirq_dmi_table[] = {
1121 	{
1122 		.callback = fix_broken_hp_bios_irq9,
1123 		.ident = "HP Pavilion N5400 Series Laptop",
1124 		.matches = {
1125 			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1126 			DMI_MATCH(DMI_BIOS_VERSION, "GE.M1.03"),
1127 			DMI_MATCH(DMI_PRODUCT_VERSION,
1128 				"HP Pavilion Notebook Model GE"),
1129 			DMI_MATCH(DMI_BOARD_VERSION, "OmniBook N32N-736"),
1130 		},
1131 	},
1132 	{
1133 		.callback = fix_acer_tm360_irqrouting,
1134 		.ident = "Acer TravelMate 36x Laptop",
1135 		.matches = {
1136 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1137 			DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 360"),
1138 		},
1139 	},
1140 	{ }
1141 };
1142 
1143 int __init pcibios_irq_init(void)
1144 {
1145 	DBG(KERN_DEBUG "PCI: IRQ init\n");
1146 
1147 	if (pcibios_enable_irq || raw_pci_ops == NULL)
1148 		return 0;
1149 
1150 	dmi_check_system(pciirq_dmi_table);
1151 
1152 	pirq_table = pirq_find_routing_table();
1153 
1154 #ifdef CONFIG_PCI_BIOS
1155 	if (!pirq_table && (pci_probe & PCI_BIOS_IRQ_SCAN))
1156 		pirq_table = pcibios_get_irq_routing_table();
1157 #endif
1158 	if (pirq_table) {
1159 		pirq_peer_trick();
1160 		pirq_find_router(&pirq_router);
1161 		if (pirq_table->exclusive_irqs) {
1162 			int i;
1163 			for (i = 0; i < 16; i++)
1164 				if (!(pirq_table->exclusive_irqs & (1 << i)))
1165 					pirq_penalty[i] += 100;
1166 		}
1167 		/*
1168 		 * If we're using the I/O APIC, avoid using the PCI IRQ
1169 		 * routing table
1170 		 */
1171 		if (io_apic_assign_pci_irqs)
1172 			pirq_table = NULL;
1173 	}
1174 
1175 	pcibios_enable_irq = pirq_enable_irq;
1176 
1177 	pcibios_fixup_irqs();
1178 	return 0;
1179 }
1180 
1181 static void pirq_penalize_isa_irq(int irq, int active)
1182 {
1183 	/*
1184 	 *  If any ISAPnP device reports an IRQ in its list of possible
1185 	 *  IRQ's, we try to avoid assigning it to PCI devices.
1186 	 */
1187 	if (irq < 16) {
1188 		if (active)
1189 			pirq_penalty[irq] += 1000;
1190 		else
1191 			pirq_penalty[irq] += 100;
1192 	}
1193 }
1194 
1195 void pcibios_penalize_isa_irq(int irq, int active)
1196 {
1197 #ifdef CONFIG_ACPI
1198 	if (!acpi_noirq)
1199 		acpi_penalize_isa_irq(irq, active);
1200 	else
1201 #endif
1202 		pirq_penalize_isa_irq(irq, active);
1203 }
1204 
1205 static int pirq_enable_irq(struct pci_dev *dev)
1206 {
1207 	u8 pin;
1208 	struct pci_dev *temp_dev;
1209 
1210 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
1211 	if (pin && !pcibios_lookup_irq(dev, 1) && !dev->irq) {
1212 		char *msg = "";
1213 
1214 		pin--; /* interrupt pins are numbered starting from 1 */
1215 
1216 		if (io_apic_assign_pci_irqs) {
1217 			int irq;
1218 
1219 			irq = IO_APIC_get_PCI_irq_vector(dev->bus->number, PCI_SLOT(dev->devfn), pin);
1220 			/*
1221 			 * Busses behind bridges are typically not listed in the MP-table.
1222 			 * In this case we have to look up the IRQ based on the parent bus,
1223 			 * parent slot, and pin number. The SMP code detects such bridged
1224 			 * busses itself so we should get into this branch reliably.
1225 			 */
1226 			temp_dev = dev;
1227 			while (irq < 0 && dev->bus->parent) { /* go back to the bridge */
1228 				struct pci_dev *bridge = dev->bus->self;
1229 
1230 				pin = (pin + PCI_SLOT(dev->devfn)) % 4;
1231 				irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
1232 						PCI_SLOT(bridge->devfn), pin);
1233 				if (irq >= 0)
1234 					printk(KERN_WARNING
1235 						"PCI: using PPB %s[%c] to get irq %d\n",
1236 						pci_name(bridge),
1237 						'A' + pin, irq);
1238 				dev = bridge;
1239 			}
1240 			dev = temp_dev;
1241 			if (irq >= 0) {
1242 				printk(KERN_INFO
1243 					"PCI->APIC IRQ transform: %s[%c] -> IRQ %d\n",
1244 					pci_name(dev), 'A' + pin, irq);
1245 				dev->irq = irq;
1246 				return 0;
1247 			} else
1248 				msg = " Probably buggy MP table.";
1249 		} else if (pci_probe & PCI_BIOS_IRQ_SCAN)
1250 			msg = "";
1251 		else
1252 			msg = " Please try using pci=biosirq.";
1253 
1254 		/*
1255 		 * With IDE legacy devices the IRQ lookup failure is not
1256 		 * a problem..
1257 		 */
1258 		if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
1259 				!(dev->class & 0x5))
1260 			return 0;
1261 
1262 		printk(KERN_WARNING
1263 			"PCI: No IRQ known for interrupt pin %c of device %s.%s\n",
1264 			'A' + pin, pci_name(dev), msg);
1265 	}
1266 	return 0;
1267 }
1268