xref: /linux/arch/x86/pci/irq.c (revision c98be0c96db00e9b6b02d31e0fa7590c54cdaaac)
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/interrupt.h>
12 #include <linux/dmi.h>
13 #include <linux/io.h>
14 #include <linux/smp.h>
15 #include <asm/io_apic.h>
16 #include <linux/irq.h>
17 #include <linux/acpi.h>
18 #include <asm/pci_x86.h>
19 
20 #define PIRQ_SIGNATURE	(('$' << 0) + ('P' << 8) + ('I' << 16) + ('R' << 24))
21 #define PIRQ_VERSION 0x0100
22 
23 static int broken_hp_bios_irq9;
24 static int acer_tm360_irqrouting;
25 
26 static struct irq_routing_table *pirq_table;
27 
28 static int pirq_enable_irq(struct pci_dev *dev);
29 
30 /*
31  * Never use: 0, 1, 2 (timer, keyboard, and cascade)
32  * Avoid using: 13, 14 and 15 (FP error and IDE).
33  * Penalize: 3, 4, 6, 7, 12 (known ISA uses: serial, floppy, parallel and mouse)
34  */
35 unsigned int pcibios_irq_mask = 0xfff8;
36 
37 static int pirq_penalty[16] = {
38 	1000000, 1000000, 1000000, 1000, 1000, 0, 1000, 1000,
39 	0, 0, 0, 0, 1000, 100000, 100000, 100000
40 };
41 
42 struct irq_router {
43 	char *name;
44 	u16 vendor, device;
45 	int (*get)(struct pci_dev *router, struct pci_dev *dev, int pirq);
46 	int (*set)(struct pci_dev *router, struct pci_dev *dev, int pirq,
47 		int new);
48 };
49 
50 struct irq_router_handler {
51 	u16 vendor;
52 	int (*probe)(struct irq_router *r, struct pci_dev *router, u16 device);
53 };
54 
55 int (*pcibios_enable_irq)(struct pci_dev *dev) = pirq_enable_irq;
56 void (*pcibios_disable_irq)(struct pci_dev *dev) = NULL;
57 
58 /*
59  *  Check passed address for the PCI IRQ Routing Table signature
60  *  and perform checksum verification.
61  */
62 
63 static inline struct irq_routing_table *pirq_check_routing_table(u8 *addr)
64 {
65 	struct irq_routing_table *rt;
66 	int i;
67 	u8 sum;
68 
69 	rt = (struct irq_routing_table *) addr;
70 	if (rt->signature != PIRQ_SIGNATURE ||
71 	    rt->version != PIRQ_VERSION ||
72 	    rt->size % 16 ||
73 	    rt->size < sizeof(struct irq_routing_table))
74 		return NULL;
75 	sum = 0;
76 	for (i = 0; i < rt->size; i++)
77 		sum += addr[i];
78 	if (!sum) {
79 		DBG(KERN_DEBUG "PCI: Interrupt Routing Table found at 0x%p\n",
80 			rt);
81 		return rt;
82 	}
83 	return NULL;
84 }
85 
86 
87 
88 /*
89  *  Search 0xf0000 -- 0xfffff for the PCI IRQ Routing Table.
90  */
91 
92 static struct irq_routing_table * __init pirq_find_routing_table(void)
93 {
94 	u8 *addr;
95 	struct irq_routing_table *rt;
96 
97 	if (pirq_table_addr) {
98 		rt = pirq_check_routing_table((u8 *) __va(pirq_table_addr));
99 		if (rt)
100 			return rt;
101 		printk(KERN_WARNING "PCI: PIRQ table NOT found at pirqaddr\n");
102 	}
103 	for (addr = (u8 *) __va(0xf0000); addr < (u8 *) __va(0x100000); addr += 16) {
104 		rt = pirq_check_routing_table(addr);
105 		if (rt)
106 			return rt;
107 	}
108 	return NULL;
109 }
110 
111 /*
112  *  If we have a IRQ routing table, use it to search for peer host
113  *  bridges.  It's a gross hack, but since there are no other known
114  *  ways how to get a list of buses, we have to go this way.
115  */
116 
117 static void __init pirq_peer_trick(void)
118 {
119 	struct irq_routing_table *rt = pirq_table;
120 	u8 busmap[256];
121 	int i;
122 	struct irq_info *e;
123 
124 	memset(busmap, 0, sizeof(busmap));
125 	for (i = 0; i < (rt->size - sizeof(struct irq_routing_table)) / sizeof(struct irq_info); i++) {
126 		e = &rt->slots[i];
127 #ifdef DEBUG
128 		{
129 			int j;
130 			DBG(KERN_DEBUG "%02x:%02x slot=%02x", e->bus, e->devfn/8, e->slot);
131 			for (j = 0; j < 4; j++)
132 				DBG(" %d:%02x/%04x", j, e->irq[j].link, e->irq[j].bitmap);
133 			DBG("\n");
134 		}
135 #endif
136 		busmap[e->bus] = 1;
137 	}
138 	for (i = 1; i < 256; i++) {
139 		if (!busmap[i] || pci_find_bus(0, i))
140 			continue;
141 		pcibios_scan_root(i);
142 	}
143 	pcibios_last_bus = -1;
144 }
145 
146 /*
147  *  Code for querying and setting of IRQ routes on various interrupt routers.
148  */
149 
150 void eisa_set_level_irq(unsigned int irq)
151 {
152 	unsigned char mask = 1 << (irq & 7);
153 	unsigned int port = 0x4d0 + (irq >> 3);
154 	unsigned char val;
155 	static u16 eisa_irq_mask;
156 
157 	if (irq >= 16 || (1 << irq) & eisa_irq_mask)
158 		return;
159 
160 	eisa_irq_mask |= (1 << irq);
161 	printk(KERN_DEBUG "PCI: setting IRQ %u as level-triggered\n", irq);
162 	val = inb(port);
163 	if (!(val & mask)) {
164 		DBG(KERN_DEBUG " -> edge");
165 		outb(val | mask, port);
166 	}
167 }
168 
169 /*
170  * Common IRQ routing practice: nibbles in config space,
171  * offset by some magic constant.
172  */
173 static unsigned int read_config_nybble(struct pci_dev *router, unsigned offset, unsigned nr)
174 {
175 	u8 x;
176 	unsigned reg = offset + (nr >> 1);
177 
178 	pci_read_config_byte(router, reg, &x);
179 	return (nr & 1) ? (x >> 4) : (x & 0xf);
180 }
181 
182 static void write_config_nybble(struct pci_dev *router, unsigned offset,
183 	unsigned nr, unsigned int val)
184 {
185 	u8 x;
186 	unsigned reg = offset + (nr >> 1);
187 
188 	pci_read_config_byte(router, reg, &x);
189 	x = (nr & 1) ? ((x & 0x0f) | (val << 4)) : ((x & 0xf0) | val);
190 	pci_write_config_byte(router, reg, x);
191 }
192 
193 /*
194  * ALI pirq entries are damn ugly, and completely undocumented.
195  * This has been figured out from pirq tables, and it's not a pretty
196  * picture.
197  */
198 static int pirq_ali_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
199 {
200 	static const unsigned char irqmap[16] = { 0, 9, 3, 10, 4, 5, 7, 6, 1, 11, 0, 12, 0, 14, 0, 15 };
201 
202 	WARN_ON_ONCE(pirq > 16);
203 	return irqmap[read_config_nybble(router, 0x48, pirq-1)];
204 }
205 
206 static int pirq_ali_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
207 {
208 	static const unsigned char irqmap[16] = { 0, 8, 0, 2, 4, 5, 7, 6, 0, 1, 3, 9, 11, 0, 13, 15 };
209 	unsigned int val = irqmap[irq];
210 
211 	WARN_ON_ONCE(pirq > 16);
212 	if (val) {
213 		write_config_nybble(router, 0x48, pirq-1, val);
214 		return 1;
215 	}
216 	return 0;
217 }
218 
219 /*
220  * The Intel PIIX4 pirq rules are fairly simple: "pirq" is
221  * just a pointer to the config space.
222  */
223 static int pirq_piix_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
224 {
225 	u8 x;
226 
227 	pci_read_config_byte(router, pirq, &x);
228 	return (x < 16) ? x : 0;
229 }
230 
231 static int pirq_piix_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
232 {
233 	pci_write_config_byte(router, pirq, irq);
234 	return 1;
235 }
236 
237 /*
238  * The VIA pirq rules are nibble-based, like ALI,
239  * but without the ugly irq number munging.
240  * However, PIRQD is in the upper instead of lower 4 bits.
241  */
242 static int pirq_via_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
243 {
244 	return read_config_nybble(router, 0x55, pirq == 4 ? 5 : pirq);
245 }
246 
247 static int pirq_via_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
248 {
249 	write_config_nybble(router, 0x55, pirq == 4 ? 5 : pirq, irq);
250 	return 1;
251 }
252 
253 /*
254  * The VIA pirq rules are nibble-based, like ALI,
255  * but without the ugly irq number munging.
256  * However, for 82C586, nibble map is different .
257  */
258 static int pirq_via586_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
259 {
260 	static const unsigned int pirqmap[5] = { 3, 2, 5, 1, 1 };
261 
262 	WARN_ON_ONCE(pirq > 5);
263 	return read_config_nybble(router, 0x55, pirqmap[pirq-1]);
264 }
265 
266 static int pirq_via586_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
267 {
268 	static const unsigned int pirqmap[5] = { 3, 2, 5, 1, 1 };
269 
270 	WARN_ON_ONCE(pirq > 5);
271 	write_config_nybble(router, 0x55, pirqmap[pirq-1], irq);
272 	return 1;
273 }
274 
275 /*
276  * ITE 8330G pirq rules are nibble-based
277  * FIXME: pirqmap may be { 1, 0, 3, 2 },
278  * 	  2+3 are both mapped to irq 9 on my system
279  */
280 static int pirq_ite_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
281 {
282 	static const unsigned char pirqmap[4] = { 1, 0, 2, 3 };
283 
284 	WARN_ON_ONCE(pirq > 4);
285 	return read_config_nybble(router, 0x43, pirqmap[pirq-1]);
286 }
287 
288 static int pirq_ite_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
289 {
290 	static const unsigned char pirqmap[4] = { 1, 0, 2, 3 };
291 
292 	WARN_ON_ONCE(pirq > 4);
293 	write_config_nybble(router, 0x43, pirqmap[pirq-1], irq);
294 	return 1;
295 }
296 
297 /*
298  * OPTI: high four bits are nibble pointer..
299  * I wonder what the low bits do?
300  */
301 static int pirq_opti_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
302 {
303 	return read_config_nybble(router, 0xb8, pirq >> 4);
304 }
305 
306 static int pirq_opti_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
307 {
308 	write_config_nybble(router, 0xb8, pirq >> 4, irq);
309 	return 1;
310 }
311 
312 /*
313  * Cyrix: nibble offset 0x5C
314  * 0x5C bits 7:4 is INTB bits 3:0 is INTA
315  * 0x5D bits 7:4 is INTD bits 3:0 is INTC
316  */
317 static int pirq_cyrix_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
318 {
319 	return read_config_nybble(router, 0x5C, (pirq-1)^1);
320 }
321 
322 static int pirq_cyrix_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
323 {
324 	write_config_nybble(router, 0x5C, (pirq-1)^1, irq);
325 	return 1;
326 }
327 
328 /*
329  *	PIRQ routing for SiS 85C503 router used in several SiS chipsets.
330  *	We have to deal with the following issues here:
331  *	- vendors have different ideas about the meaning of link values
332  *	- some onboard devices (integrated in the chipset) have special
333  *	  links and are thus routed differently (i.e. not via PCI INTA-INTD)
334  *	- different revision of the router have a different layout for
335  *	  the routing registers, particularly for the onchip devices
336  *
337  *	For all routing registers the common thing is we have one byte
338  *	per routeable link which is defined as:
339  *		 bit 7      IRQ mapping enabled (0) or disabled (1)
340  *		 bits [6:4] reserved (sometimes used for onchip devices)
341  *		 bits [3:0] IRQ to map to
342  *		     allowed: 3-7, 9-12, 14-15
343  *		     reserved: 0, 1, 2, 8, 13
344  *
345  *	The config-space registers located at 0x41/0x42/0x43/0x44 are
346  *	always used to route the normal PCI INT A/B/C/D respectively.
347  *	Apparently there are systems implementing PCI routing table using
348  *	link values 0x01-0x04 and others using 0x41-0x44 for PCI INTA..D.
349  *	We try our best to handle both link mappings.
350  *
351  *	Currently (2003-05-21) it appears most SiS chipsets follow the
352  *	definition of routing registers from the SiS-5595 southbridge.
353  *	According to the SiS 5595 datasheets the revision id's of the
354  *	router (ISA-bridge) should be 0x01 or 0xb0.
355  *
356  *	Furthermore we've also seen lspci dumps with revision 0x00 and 0xb1.
357  *	Looks like these are used in a number of SiS 5xx/6xx/7xx chipsets.
358  *	They seem to work with the current routing code. However there is
359  *	some concern because of the two USB-OHCI HCs (original SiS 5595
360  *	had only one). YMMV.
361  *
362  *	Onchip routing for router rev-id 0x01/0xb0 and probably 0x00/0xb1:
363  *
364  *	0x61:	IDEIRQ:
365  *		bits [6:5] must be written 01
366  *		bit 4 channel-select primary (0), secondary (1)
367  *
368  *	0x62:	USBIRQ:
369  *		bit 6 OHCI function disabled (0), enabled (1)
370  *
371  *	0x6a:	ACPI/SCI IRQ: bits 4-6 reserved
372  *
373  *	0x7e:	Data Acq. Module IRQ - bits 4-6 reserved
374  *
375  *	We support USBIRQ (in addition to INTA-INTD) and keep the
376  *	IDE, ACPI and DAQ routing untouched as set by the BIOS.
377  *
378  *	Currently the only reported exception is the new SiS 65x chipset
379  *	which includes the SiS 69x southbridge. Here we have the 85C503
380  *	router revision 0x04 and there are changes in the register layout
381  *	mostly related to the different USB HCs with USB 2.0 support.
382  *
383  *	Onchip routing for router rev-id 0x04 (try-and-error observation)
384  *
385  *	0x60/0x61/0x62/0x63:	1xEHCI and 3xOHCI (companion) USB-HCs
386  *				bit 6-4 are probably unused, not like 5595
387  */
388 
389 #define PIRQ_SIS_IRQ_MASK	0x0f
390 #define PIRQ_SIS_IRQ_DISABLE	0x80
391 #define PIRQ_SIS_USB_ENABLE	0x40
392 
393 static int pirq_sis_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
394 {
395 	u8 x;
396 	int reg;
397 
398 	reg = pirq;
399 	if (reg >= 0x01 && reg <= 0x04)
400 		reg += 0x40;
401 	pci_read_config_byte(router, reg, &x);
402 	return (x & PIRQ_SIS_IRQ_DISABLE) ? 0 : (x & PIRQ_SIS_IRQ_MASK);
403 }
404 
405 static int pirq_sis_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
406 {
407 	u8 x;
408 	int reg;
409 
410 	reg = pirq;
411 	if (reg >= 0x01 && reg <= 0x04)
412 		reg += 0x40;
413 	pci_read_config_byte(router, reg, &x);
414 	x &= ~(PIRQ_SIS_IRQ_MASK | PIRQ_SIS_IRQ_DISABLE);
415 	x |= irq ? irq: PIRQ_SIS_IRQ_DISABLE;
416 	pci_write_config_byte(router, reg, x);
417 	return 1;
418 }
419 
420 
421 /*
422  * VLSI: nibble offset 0x74 - educated guess due to routing table and
423  *       config space of VLSI 82C534 PCI-bridge/router (1004:0102)
424  *       Tested on HP OmniBook 800 covering PIRQ 1, 2, 4, 8 for onboard
425  *       devices, PIRQ 3 for non-pci(!) soundchip and (untested) PIRQ 6
426  *       for the busbridge to the docking station.
427  */
428 
429 static int pirq_vlsi_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
430 {
431 	WARN_ON_ONCE(pirq >= 9);
432 	if (pirq > 8) {
433 		dev_info(&dev->dev, "VLSI router PIRQ escape (%d)\n", pirq);
434 		return 0;
435 	}
436 	return read_config_nybble(router, 0x74, pirq-1);
437 }
438 
439 static int pirq_vlsi_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
440 {
441 	WARN_ON_ONCE(pirq >= 9);
442 	if (pirq > 8) {
443 		dev_info(&dev->dev, "VLSI router PIRQ escape (%d)\n", pirq);
444 		return 0;
445 	}
446 	write_config_nybble(router, 0x74, pirq-1, irq);
447 	return 1;
448 }
449 
450 /*
451  * ServerWorks: PCI interrupts mapped to system IRQ lines through Index
452  * and Redirect I/O registers (0x0c00 and 0x0c01).  The Index register
453  * format is (PCIIRQ## | 0x10), e.g.: PCIIRQ10=0x1a.  The Redirect
454  * register is a straight binary coding of desired PIC IRQ (low nibble).
455  *
456  * The 'link' value in the PIRQ table is already in the correct format
457  * for the Index register.  There are some special index values:
458  * 0x00 for ACPI (SCI), 0x01 for USB, 0x02 for IDE0, 0x04 for IDE1,
459  * and 0x03 for SMBus.
460  */
461 static int pirq_serverworks_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
462 {
463 	outb(pirq, 0xc00);
464 	return inb(0xc01) & 0xf;
465 }
466 
467 static int pirq_serverworks_set(struct pci_dev *router, struct pci_dev *dev,
468 	int pirq, int irq)
469 {
470 	outb(pirq, 0xc00);
471 	outb(irq, 0xc01);
472 	return 1;
473 }
474 
475 /* Support for AMD756 PCI IRQ Routing
476  * Jhon H. Caicedo <jhcaiced@osso.org.co>
477  * Jun/21/2001 0.2.0 Release, fixed to use "nybble" functions... (jhcaiced)
478  * Jun/19/2001 Alpha Release 0.1.0 (jhcaiced)
479  * The AMD756 pirq rules are nibble-based
480  * offset 0x56 0-3 PIRQA  4-7  PIRQB
481  * offset 0x57 0-3 PIRQC  4-7  PIRQD
482  */
483 static int pirq_amd756_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
484 {
485 	u8 irq;
486 	irq = 0;
487 	if (pirq <= 4)
488 		irq = read_config_nybble(router, 0x56, pirq - 1);
489 	dev_info(&dev->dev,
490 		 "AMD756: dev [%04x:%04x], router PIRQ %d get IRQ %d\n",
491 		 dev->vendor, dev->device, pirq, irq);
492 	return irq;
493 }
494 
495 static int pirq_amd756_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
496 {
497 	dev_info(&dev->dev,
498 		 "AMD756: dev [%04x:%04x], router PIRQ %d set IRQ %d\n",
499 		 dev->vendor, dev->device, pirq, irq);
500 	if (pirq <= 4)
501 		write_config_nybble(router, 0x56, pirq - 1, irq);
502 	return 1;
503 }
504 
505 /*
506  * PicoPower PT86C523
507  */
508 static int pirq_pico_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
509 {
510 	outb(0x10 + ((pirq - 1) >> 1), 0x24);
511 	return ((pirq - 1) & 1) ? (inb(0x26) >> 4) : (inb(0x26) & 0xf);
512 }
513 
514 static int pirq_pico_set(struct pci_dev *router, struct pci_dev *dev, int pirq,
515 			int irq)
516 {
517 	unsigned int x;
518 	outb(0x10 + ((pirq - 1) >> 1), 0x24);
519 	x = inb(0x26);
520 	x = ((pirq - 1) & 1) ? ((x & 0x0f) | (irq << 4)) : ((x & 0xf0) | (irq));
521 	outb(x, 0x26);
522 	return 1;
523 }
524 
525 #ifdef CONFIG_PCI_BIOS
526 
527 static int pirq_bios_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
528 {
529 	struct pci_dev *bridge;
530 	int pin = pci_get_interrupt_pin(dev, &bridge);
531 	return pcibios_set_irq_routing(bridge, pin - 1, irq);
532 }
533 
534 #endif
535 
536 static __init int intel_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
537 {
538 	static struct pci_device_id __initdata pirq_440gx[] = {
539 		{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_0) },
540 		{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_2) },
541 		{ },
542 	};
543 
544 	/* 440GX has a proprietary PIRQ router -- don't use it */
545 	if (pci_dev_present(pirq_440gx))
546 		return 0;
547 
548 	switch (device) {
549 	case PCI_DEVICE_ID_INTEL_82371FB_0:
550 	case PCI_DEVICE_ID_INTEL_82371SB_0:
551 	case PCI_DEVICE_ID_INTEL_82371AB_0:
552 	case PCI_DEVICE_ID_INTEL_82371MX:
553 	case PCI_DEVICE_ID_INTEL_82443MX_0:
554 	case PCI_DEVICE_ID_INTEL_82801AA_0:
555 	case PCI_DEVICE_ID_INTEL_82801AB_0:
556 	case PCI_DEVICE_ID_INTEL_82801BA_0:
557 	case PCI_DEVICE_ID_INTEL_82801BA_10:
558 	case PCI_DEVICE_ID_INTEL_82801CA_0:
559 	case PCI_DEVICE_ID_INTEL_82801CA_12:
560 	case PCI_DEVICE_ID_INTEL_82801DB_0:
561 	case PCI_DEVICE_ID_INTEL_82801E_0:
562 	case PCI_DEVICE_ID_INTEL_82801EB_0:
563 	case PCI_DEVICE_ID_INTEL_ESB_1:
564 	case PCI_DEVICE_ID_INTEL_ICH6_0:
565 	case PCI_DEVICE_ID_INTEL_ICH6_1:
566 	case PCI_DEVICE_ID_INTEL_ICH7_0:
567 	case PCI_DEVICE_ID_INTEL_ICH7_1:
568 	case PCI_DEVICE_ID_INTEL_ICH7_30:
569 	case PCI_DEVICE_ID_INTEL_ICH7_31:
570 	case PCI_DEVICE_ID_INTEL_TGP_LPC:
571 	case PCI_DEVICE_ID_INTEL_ESB2_0:
572 	case PCI_DEVICE_ID_INTEL_ICH8_0:
573 	case PCI_DEVICE_ID_INTEL_ICH8_1:
574 	case PCI_DEVICE_ID_INTEL_ICH8_2:
575 	case PCI_DEVICE_ID_INTEL_ICH8_3:
576 	case PCI_DEVICE_ID_INTEL_ICH8_4:
577 	case PCI_DEVICE_ID_INTEL_ICH9_0:
578 	case PCI_DEVICE_ID_INTEL_ICH9_1:
579 	case PCI_DEVICE_ID_INTEL_ICH9_2:
580 	case PCI_DEVICE_ID_INTEL_ICH9_3:
581 	case PCI_DEVICE_ID_INTEL_ICH9_4:
582 	case PCI_DEVICE_ID_INTEL_ICH9_5:
583 	case PCI_DEVICE_ID_INTEL_EP80579_0:
584 	case PCI_DEVICE_ID_INTEL_ICH10_0:
585 	case PCI_DEVICE_ID_INTEL_ICH10_1:
586 	case PCI_DEVICE_ID_INTEL_ICH10_2:
587 	case PCI_DEVICE_ID_INTEL_ICH10_3:
588 	case PCI_DEVICE_ID_INTEL_PATSBURG_LPC_0:
589 	case PCI_DEVICE_ID_INTEL_PATSBURG_LPC_1:
590 		r->name = "PIIX/ICH";
591 		r->get = pirq_piix_get;
592 		r->set = pirq_piix_set;
593 		return 1;
594 	}
595 
596 	if ((device >= PCI_DEVICE_ID_INTEL_5_3400_SERIES_LPC_MIN &&
597 	     device <= PCI_DEVICE_ID_INTEL_5_3400_SERIES_LPC_MAX)
598 	||  (device >= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MIN &&
599 	     device <= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MAX)
600 	||  (device >= PCI_DEVICE_ID_INTEL_DH89XXCC_LPC_MIN &&
601 	     device <= PCI_DEVICE_ID_INTEL_DH89XXCC_LPC_MAX)
602 	||  (device >= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MIN &&
603 	     device <= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MAX)) {
604 		r->name = "PIIX/ICH";
605 		r->get = pirq_piix_get;
606 		r->set = pirq_piix_set;
607 		return 1;
608 	}
609 
610 	return 0;
611 }
612 
613 static __init int via_router_probe(struct irq_router *r,
614 				struct pci_dev *router, u16 device)
615 {
616 	/* FIXME: We should move some of the quirk fixup stuff here */
617 
618 	/*
619 	 * workarounds for some buggy BIOSes
620 	 */
621 	if (device == PCI_DEVICE_ID_VIA_82C586_0) {
622 		switch (router->device) {
623 		case PCI_DEVICE_ID_VIA_82C686:
624 			/*
625 			 * Asus k7m bios wrongly reports 82C686A
626 			 * as 586-compatible
627 			 */
628 			device = PCI_DEVICE_ID_VIA_82C686;
629 			break;
630 		case PCI_DEVICE_ID_VIA_8235:
631 			/**
632 			 * Asus a7v-x bios wrongly reports 8235
633 			 * as 586-compatible
634 			 */
635 			device = PCI_DEVICE_ID_VIA_8235;
636 			break;
637 		case PCI_DEVICE_ID_VIA_8237:
638 			/**
639 			 * Asus a7v600 bios wrongly reports 8237
640 			 * as 586-compatible
641 			 */
642 			device = PCI_DEVICE_ID_VIA_8237;
643 			break;
644 		}
645 	}
646 
647 	switch (device) {
648 	case PCI_DEVICE_ID_VIA_82C586_0:
649 		r->name = "VIA";
650 		r->get = pirq_via586_get;
651 		r->set = pirq_via586_set;
652 		return 1;
653 	case PCI_DEVICE_ID_VIA_82C596:
654 	case PCI_DEVICE_ID_VIA_82C686:
655 	case PCI_DEVICE_ID_VIA_8231:
656 	case PCI_DEVICE_ID_VIA_8233A:
657 	case PCI_DEVICE_ID_VIA_8235:
658 	case PCI_DEVICE_ID_VIA_8237:
659 		/* FIXME: add new ones for 8233/5 */
660 		r->name = "VIA";
661 		r->get = pirq_via_get;
662 		r->set = pirq_via_set;
663 		return 1;
664 	}
665 	return 0;
666 }
667 
668 static __init int vlsi_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
669 {
670 	switch (device) {
671 	case PCI_DEVICE_ID_VLSI_82C534:
672 		r->name = "VLSI 82C534";
673 		r->get = pirq_vlsi_get;
674 		r->set = pirq_vlsi_set;
675 		return 1;
676 	}
677 	return 0;
678 }
679 
680 
681 static __init int serverworks_router_probe(struct irq_router *r,
682 		struct pci_dev *router, u16 device)
683 {
684 	switch (device) {
685 	case PCI_DEVICE_ID_SERVERWORKS_OSB4:
686 	case PCI_DEVICE_ID_SERVERWORKS_CSB5:
687 		r->name = "ServerWorks";
688 		r->get = pirq_serverworks_get;
689 		r->set = pirq_serverworks_set;
690 		return 1;
691 	}
692 	return 0;
693 }
694 
695 static __init int sis_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
696 {
697 	if (device != PCI_DEVICE_ID_SI_503)
698 		return 0;
699 
700 	r->name = "SIS";
701 	r->get = pirq_sis_get;
702 	r->set = pirq_sis_set;
703 	return 1;
704 }
705 
706 static __init int cyrix_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
707 {
708 	switch (device) {
709 	case PCI_DEVICE_ID_CYRIX_5520:
710 		r->name = "NatSemi";
711 		r->get = pirq_cyrix_get;
712 		r->set = pirq_cyrix_set;
713 		return 1;
714 	}
715 	return 0;
716 }
717 
718 static __init int opti_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
719 {
720 	switch (device) {
721 	case PCI_DEVICE_ID_OPTI_82C700:
722 		r->name = "OPTI";
723 		r->get = pirq_opti_get;
724 		r->set = pirq_opti_set;
725 		return 1;
726 	}
727 	return 0;
728 }
729 
730 static __init int ite_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
731 {
732 	switch (device) {
733 	case PCI_DEVICE_ID_ITE_IT8330G_0:
734 		r->name = "ITE";
735 		r->get = pirq_ite_get;
736 		r->set = pirq_ite_set;
737 		return 1;
738 	}
739 	return 0;
740 }
741 
742 static __init int ali_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
743 {
744 	switch (device) {
745 	case PCI_DEVICE_ID_AL_M1533:
746 	case PCI_DEVICE_ID_AL_M1563:
747 		r->name = "ALI";
748 		r->get = pirq_ali_get;
749 		r->set = pirq_ali_set;
750 		return 1;
751 	}
752 	return 0;
753 }
754 
755 static __init int amd_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
756 {
757 	switch (device) {
758 	case PCI_DEVICE_ID_AMD_VIPER_740B:
759 		r->name = "AMD756";
760 		break;
761 	case PCI_DEVICE_ID_AMD_VIPER_7413:
762 		r->name = "AMD766";
763 		break;
764 	case PCI_DEVICE_ID_AMD_VIPER_7443:
765 		r->name = "AMD768";
766 		break;
767 	default:
768 		return 0;
769 	}
770 	r->get = pirq_amd756_get;
771 	r->set = pirq_amd756_set;
772 	return 1;
773 }
774 
775 static __init int pico_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
776 {
777 	switch (device) {
778 	case PCI_DEVICE_ID_PICOPOWER_PT86C523:
779 		r->name = "PicoPower PT86C523";
780 		r->get = pirq_pico_get;
781 		r->set = pirq_pico_set;
782 		return 1;
783 
784 	case PCI_DEVICE_ID_PICOPOWER_PT86C523BBP:
785 		r->name = "PicoPower PT86C523 rev. BB+";
786 		r->get = pirq_pico_get;
787 		r->set = pirq_pico_set;
788 		return 1;
789 	}
790 	return 0;
791 }
792 
793 static __initdata struct irq_router_handler pirq_routers[] = {
794 	{ PCI_VENDOR_ID_INTEL, intel_router_probe },
795 	{ PCI_VENDOR_ID_AL, ali_router_probe },
796 	{ PCI_VENDOR_ID_ITE, ite_router_probe },
797 	{ PCI_VENDOR_ID_VIA, via_router_probe },
798 	{ PCI_VENDOR_ID_OPTI, opti_router_probe },
799 	{ PCI_VENDOR_ID_SI, sis_router_probe },
800 	{ PCI_VENDOR_ID_CYRIX, cyrix_router_probe },
801 	{ PCI_VENDOR_ID_VLSI, vlsi_router_probe },
802 	{ PCI_VENDOR_ID_SERVERWORKS, serverworks_router_probe },
803 	{ PCI_VENDOR_ID_AMD, amd_router_probe },
804 	{ PCI_VENDOR_ID_PICOPOWER, pico_router_probe },
805 	/* Someone with docs needs to add the ATI Radeon IGP */
806 	{ 0, NULL }
807 };
808 static struct irq_router pirq_router;
809 static struct pci_dev *pirq_router_dev;
810 
811 
812 /*
813  *	FIXME: should we have an option to say "generic for
814  *	chipset" ?
815  */
816 
817 static void __init pirq_find_router(struct irq_router *r)
818 {
819 	struct irq_routing_table *rt = pirq_table;
820 	struct irq_router_handler *h;
821 
822 #ifdef CONFIG_PCI_BIOS
823 	if (!rt->signature) {
824 		printk(KERN_INFO "PCI: Using BIOS for IRQ routing\n");
825 		r->set = pirq_bios_set;
826 		r->name = "BIOS";
827 		return;
828 	}
829 #endif
830 
831 	/* Default unless a driver reloads it */
832 	r->name = "default";
833 	r->get = NULL;
834 	r->set = NULL;
835 
836 	DBG(KERN_DEBUG "PCI: Attempting to find IRQ router for [%04x:%04x]\n",
837 	    rt->rtr_vendor, rt->rtr_device);
838 
839 	pirq_router_dev = pci_get_bus_and_slot(rt->rtr_bus, rt->rtr_devfn);
840 	if (!pirq_router_dev) {
841 		DBG(KERN_DEBUG "PCI: Interrupt router not found at "
842 			"%02x:%02x\n", rt->rtr_bus, rt->rtr_devfn);
843 		return;
844 	}
845 
846 	for (h = pirq_routers; h->vendor; h++) {
847 		/* First look for a router match */
848 		if (rt->rtr_vendor == h->vendor &&
849 			h->probe(r, pirq_router_dev, rt->rtr_device))
850 			break;
851 		/* Fall back to a device match */
852 		if (pirq_router_dev->vendor == h->vendor &&
853 			h->probe(r, pirq_router_dev, pirq_router_dev->device))
854 			break;
855 	}
856 	dev_info(&pirq_router_dev->dev, "%s IRQ router [%04x:%04x]\n",
857 		 pirq_router.name,
858 		 pirq_router_dev->vendor, pirq_router_dev->device);
859 
860 	/* The device remains referenced for the kernel lifetime */
861 }
862 
863 static struct irq_info *pirq_get_info(struct pci_dev *dev)
864 {
865 	struct irq_routing_table *rt = pirq_table;
866 	int entries = (rt->size - sizeof(struct irq_routing_table)) /
867 		sizeof(struct irq_info);
868 	struct irq_info *info;
869 
870 	for (info = rt->slots; entries--; info++)
871 		if (info->bus == dev->bus->number &&
872 			PCI_SLOT(info->devfn) == PCI_SLOT(dev->devfn))
873 			return info;
874 	return NULL;
875 }
876 
877 static int pcibios_lookup_irq(struct pci_dev *dev, int assign)
878 {
879 	u8 pin;
880 	struct irq_info *info;
881 	int i, pirq, newirq;
882 	int irq = 0;
883 	u32 mask;
884 	struct irq_router *r = &pirq_router;
885 	struct pci_dev *dev2 = NULL;
886 	char *msg = NULL;
887 
888 	/* Find IRQ pin */
889 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
890 	if (!pin) {
891 		dev_dbg(&dev->dev, "no interrupt pin\n");
892 		return 0;
893 	}
894 
895 	if (io_apic_assign_pci_irqs)
896 		return 0;
897 
898 	/* Find IRQ routing entry */
899 
900 	if (!pirq_table)
901 		return 0;
902 
903 	info = pirq_get_info(dev);
904 	if (!info) {
905 		dev_dbg(&dev->dev, "PCI INT %c not found in routing table\n",
906 			'A' + pin - 1);
907 		return 0;
908 	}
909 	pirq = info->irq[pin - 1].link;
910 	mask = info->irq[pin - 1].bitmap;
911 	if (!pirq) {
912 		dev_dbg(&dev->dev, "PCI INT %c not routed\n", 'A' + pin - 1);
913 		return 0;
914 	}
915 	dev_dbg(&dev->dev, "PCI INT %c -> PIRQ %02x, mask %04x, excl %04x",
916 		'A' + pin - 1, pirq, mask, pirq_table->exclusive_irqs);
917 	mask &= pcibios_irq_mask;
918 
919 	/* Work around broken HP Pavilion Notebooks which assign USB to
920 	   IRQ 9 even though it is actually wired to IRQ 11 */
921 
922 	if (broken_hp_bios_irq9 && pirq == 0x59 && dev->irq == 9) {
923 		dev->irq = 11;
924 		pci_write_config_byte(dev, PCI_INTERRUPT_LINE, 11);
925 		r->set(pirq_router_dev, dev, pirq, 11);
926 	}
927 
928 	/* same for Acer Travelmate 360, but with CB and irq 11 -> 10 */
929 	if (acer_tm360_irqrouting && dev->irq == 11 &&
930 		dev->vendor == PCI_VENDOR_ID_O2) {
931 		pirq = 0x68;
932 		mask = 0x400;
933 		dev->irq = r->get(pirq_router_dev, dev, pirq);
934 		pci_write_config_byte(dev, PCI_INTERRUPT_LINE, dev->irq);
935 	}
936 
937 	/*
938 	 * Find the best IRQ to assign: use the one
939 	 * reported by the device if possible.
940 	 */
941 	newirq = dev->irq;
942 	if (newirq && !((1 << newirq) & mask)) {
943 		if (pci_probe & PCI_USE_PIRQ_MASK)
944 			newirq = 0;
945 		else
946 			dev_warn(&dev->dev, "IRQ %d doesn't match PIRQ mask "
947 				 "%#x; try pci=usepirqmask\n", newirq, mask);
948 	}
949 	if (!newirq && assign) {
950 		for (i = 0; i < 16; i++) {
951 			if (!(mask & (1 << i)))
952 				continue;
953 			if (pirq_penalty[i] < pirq_penalty[newirq] &&
954 				can_request_irq(i, IRQF_SHARED))
955 				newirq = i;
956 		}
957 	}
958 	dev_dbg(&dev->dev, "PCI INT %c -> newirq %d", 'A' + pin - 1, newirq);
959 
960 	/* Check if it is hardcoded */
961 	if ((pirq & 0xf0) == 0xf0) {
962 		irq = pirq & 0xf;
963 		msg = "hardcoded";
964 	} else if (r->get && (irq = r->get(pirq_router_dev, dev, pirq)) && \
965 	((!(pci_probe & PCI_USE_PIRQ_MASK)) || ((1 << irq) & mask))) {
966 		msg = "found";
967 		eisa_set_level_irq(irq);
968 	} else if (newirq && r->set &&
969 		(dev->class >> 8) != PCI_CLASS_DISPLAY_VGA) {
970 		if (r->set(pirq_router_dev, dev, pirq, newirq)) {
971 			eisa_set_level_irq(newirq);
972 			msg = "assigned";
973 			irq = newirq;
974 		}
975 	}
976 
977 	if (!irq) {
978 		if (newirq && mask == (1 << newirq)) {
979 			msg = "guessed";
980 			irq = newirq;
981 		} else {
982 			dev_dbg(&dev->dev, "can't route interrupt\n");
983 			return 0;
984 		}
985 	}
986 	dev_info(&dev->dev, "%s PCI INT %c -> IRQ %d\n", msg, 'A' + pin - 1, irq);
987 
988 	/* Update IRQ for all devices with the same pirq value */
989 	for_each_pci_dev(dev2) {
990 		pci_read_config_byte(dev2, PCI_INTERRUPT_PIN, &pin);
991 		if (!pin)
992 			continue;
993 
994 		info = pirq_get_info(dev2);
995 		if (!info)
996 			continue;
997 		if (info->irq[pin - 1].link == pirq) {
998 			/*
999 			 * We refuse to override the dev->irq
1000 			 * information. Give a warning!
1001 			 */
1002 			if (dev2->irq && dev2->irq != irq && \
1003 			(!(pci_probe & PCI_USE_PIRQ_MASK) || \
1004 			((1 << dev2->irq) & mask))) {
1005 #ifndef CONFIG_PCI_MSI
1006 				dev_info(&dev2->dev, "IRQ routing conflict: "
1007 					 "have IRQ %d, want IRQ %d\n",
1008 					 dev2->irq, irq);
1009 #endif
1010 				continue;
1011 			}
1012 			dev2->irq = irq;
1013 			pirq_penalty[irq]++;
1014 			if (dev != dev2)
1015 				dev_info(&dev->dev, "sharing IRQ %d with %s\n",
1016 					 irq, pci_name(dev2));
1017 		}
1018 	}
1019 	return 1;
1020 }
1021 
1022 void __init pcibios_fixup_irqs(void)
1023 {
1024 	struct pci_dev *dev = NULL;
1025 	u8 pin;
1026 
1027 	DBG(KERN_DEBUG "PCI: IRQ fixup\n");
1028 	for_each_pci_dev(dev) {
1029 		/*
1030 		 * If the BIOS has set an out of range IRQ number, just
1031 		 * ignore it.  Also keep track of which IRQ's are
1032 		 * already in use.
1033 		 */
1034 		if (dev->irq >= 16) {
1035 			dev_dbg(&dev->dev, "ignoring bogus IRQ %d\n", dev->irq);
1036 			dev->irq = 0;
1037 		}
1038 		/*
1039 		 * If the IRQ is already assigned to a PCI device,
1040 		 * ignore its ISA use penalty
1041 		 */
1042 		if (pirq_penalty[dev->irq] >= 100 &&
1043 				pirq_penalty[dev->irq] < 100000)
1044 			pirq_penalty[dev->irq] = 0;
1045 		pirq_penalty[dev->irq]++;
1046 	}
1047 
1048 	if (io_apic_assign_pci_irqs)
1049 		return;
1050 
1051 	dev = NULL;
1052 	for_each_pci_dev(dev) {
1053 		pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
1054 		if (!pin)
1055 			continue;
1056 
1057 		/*
1058 		 * Still no IRQ? Try to lookup one...
1059 		 */
1060 		if (!dev->irq)
1061 			pcibios_lookup_irq(dev, 0);
1062 	}
1063 }
1064 
1065 /*
1066  * Work around broken HP Pavilion Notebooks which assign USB to
1067  * IRQ 9 even though it is actually wired to IRQ 11
1068  */
1069 static int __init fix_broken_hp_bios_irq9(const struct dmi_system_id *d)
1070 {
1071 	if (!broken_hp_bios_irq9) {
1072 		broken_hp_bios_irq9 = 1;
1073 		printk(KERN_INFO "%s detected - fixing broken IRQ routing\n",
1074 			d->ident);
1075 	}
1076 	return 0;
1077 }
1078 
1079 /*
1080  * Work around broken Acer TravelMate 360 Notebooks which assign
1081  * Cardbus to IRQ 11 even though it is actually wired to IRQ 10
1082  */
1083 static int __init fix_acer_tm360_irqrouting(const struct dmi_system_id *d)
1084 {
1085 	if (!acer_tm360_irqrouting) {
1086 		acer_tm360_irqrouting = 1;
1087 		printk(KERN_INFO "%s detected - fixing broken IRQ routing\n",
1088 			d->ident);
1089 	}
1090 	return 0;
1091 }
1092 
1093 static struct dmi_system_id __initdata pciirq_dmi_table[] = {
1094 	{
1095 		.callback = fix_broken_hp_bios_irq9,
1096 		.ident = "HP Pavilion N5400 Series Laptop",
1097 		.matches = {
1098 			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1099 			DMI_MATCH(DMI_BIOS_VERSION, "GE.M1.03"),
1100 			DMI_MATCH(DMI_PRODUCT_VERSION,
1101 				"HP Pavilion Notebook Model GE"),
1102 			DMI_MATCH(DMI_BOARD_VERSION, "OmniBook N32N-736"),
1103 		},
1104 	},
1105 	{
1106 		.callback = fix_acer_tm360_irqrouting,
1107 		.ident = "Acer TravelMate 36x Laptop",
1108 		.matches = {
1109 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1110 			DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 360"),
1111 		},
1112 	},
1113 	{ }
1114 };
1115 
1116 void __init pcibios_irq_init(void)
1117 {
1118 	DBG(KERN_DEBUG "PCI: IRQ init\n");
1119 
1120 	if (raw_pci_ops == NULL)
1121 		return;
1122 
1123 	dmi_check_system(pciirq_dmi_table);
1124 
1125 	pirq_table = pirq_find_routing_table();
1126 
1127 #ifdef CONFIG_PCI_BIOS
1128 	if (!pirq_table && (pci_probe & PCI_BIOS_IRQ_SCAN))
1129 		pirq_table = pcibios_get_irq_routing_table();
1130 #endif
1131 	if (pirq_table) {
1132 		pirq_peer_trick();
1133 		pirq_find_router(&pirq_router);
1134 		if (pirq_table->exclusive_irqs) {
1135 			int i;
1136 			for (i = 0; i < 16; i++)
1137 				if (!(pirq_table->exclusive_irqs & (1 << i)))
1138 					pirq_penalty[i] += 100;
1139 		}
1140 		/*
1141 		 * If we're using the I/O APIC, avoid using the PCI IRQ
1142 		 * routing table
1143 		 */
1144 		if (io_apic_assign_pci_irqs)
1145 			pirq_table = NULL;
1146 	}
1147 
1148 	x86_init.pci.fixup_irqs();
1149 
1150 	if (io_apic_assign_pci_irqs && pci_routeirq) {
1151 		struct pci_dev *dev = NULL;
1152 		/*
1153 		 * PCI IRQ routing is set up by pci_enable_device(), but we
1154 		 * also do it here in case there are still broken drivers that
1155 		 * don't use pci_enable_device().
1156 		 */
1157 		printk(KERN_INFO "PCI: Routing PCI interrupts for all devices because \"pci=routeirq\" specified\n");
1158 		for_each_pci_dev(dev)
1159 			pirq_enable_irq(dev);
1160 	}
1161 }
1162 
1163 static void pirq_penalize_isa_irq(int irq, int active)
1164 {
1165 	/*
1166 	 *  If any ISAPnP device reports an IRQ in its list of possible
1167 	 *  IRQ's, we try to avoid assigning it to PCI devices.
1168 	 */
1169 	if (irq < 16) {
1170 		if (active)
1171 			pirq_penalty[irq] += 1000;
1172 		else
1173 			pirq_penalty[irq] += 100;
1174 	}
1175 }
1176 
1177 void pcibios_penalize_isa_irq(int irq, int active)
1178 {
1179 #ifdef CONFIG_ACPI
1180 	if (!acpi_noirq)
1181 		acpi_penalize_isa_irq(irq, active);
1182 	else
1183 #endif
1184 		pirq_penalize_isa_irq(irq, active);
1185 }
1186 
1187 static int pirq_enable_irq(struct pci_dev *dev)
1188 {
1189 	u8 pin;
1190 
1191 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
1192 	if (pin && !pcibios_lookup_irq(dev, 1)) {
1193 		char *msg = "";
1194 
1195 		if (!io_apic_assign_pci_irqs && dev->irq)
1196 			return 0;
1197 
1198 		if (io_apic_assign_pci_irqs) {
1199 #ifdef CONFIG_X86_IO_APIC
1200 			struct pci_dev *temp_dev;
1201 			int irq;
1202 			struct io_apic_irq_attr irq_attr;
1203 
1204 			irq = IO_APIC_get_PCI_irq_vector(dev->bus->number,
1205 						PCI_SLOT(dev->devfn),
1206 						pin - 1, &irq_attr);
1207 			/*
1208 			 * Busses behind bridges are typically not listed in the MP-table.
1209 			 * In this case we have to look up the IRQ based on the parent bus,
1210 			 * parent slot, and pin number. The SMP code detects such bridged
1211 			 * busses itself so we should get into this branch reliably.
1212 			 */
1213 			temp_dev = dev;
1214 			while (irq < 0 && dev->bus->parent) { /* go back to the bridge */
1215 				struct pci_dev *bridge = dev->bus->self;
1216 
1217 				pin = pci_swizzle_interrupt_pin(dev, pin);
1218 				irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
1219 						PCI_SLOT(bridge->devfn),
1220 						pin - 1, &irq_attr);
1221 				if (irq >= 0)
1222 					dev_warn(&dev->dev, "using bridge %s "
1223 						 "INT %c to get IRQ %d\n",
1224 						 pci_name(bridge), 'A' + pin - 1,
1225 						 irq);
1226 				dev = bridge;
1227 			}
1228 			dev = temp_dev;
1229 			if (irq >= 0) {
1230 				io_apic_set_pci_routing(&dev->dev, irq,
1231 							 &irq_attr);
1232 				dev->irq = irq;
1233 				dev_info(&dev->dev, "PCI->APIC IRQ transform: "
1234 					 "INT %c -> IRQ %d\n", 'A' + pin - 1, irq);
1235 				return 0;
1236 			} else
1237 				msg = "; probably buggy MP table";
1238 #endif
1239 		} else if (pci_probe & PCI_BIOS_IRQ_SCAN)
1240 			msg = "";
1241 		else
1242 			msg = "; please try using pci=biosirq";
1243 
1244 		/*
1245 		 * With IDE legacy devices the IRQ lookup failure is not
1246 		 * a problem..
1247 		 */
1248 		if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
1249 				!(dev->class & 0x5))
1250 			return 0;
1251 
1252 		dev_warn(&dev->dev, "can't find IRQ for PCI INT %c%s\n",
1253 			 'A' + pin - 1, msg);
1254 	}
1255 	return 0;
1256 }
1257