xref: /openbmc/linux/arch/x86/pci/irq.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
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 		int node;
140 		if (!busmap[i] || pci_find_bus(0, i))
141 			continue;
142 		node = get_mp_bus_to_node(i);
143 		if (pci_scan_bus_on_node(i, &pci_root_ops, node))
144 			printk(KERN_INFO "PCI: Discovered primary peer "
145 			       "bus %02x [IRQ]\n", i);
146 	}
147 	pcibios_last_bus = -1;
148 }
149 
150 /*
151  *  Code for querying and setting of IRQ routes on various interrupt routers.
152  */
153 
154 void eisa_set_level_irq(unsigned int irq)
155 {
156 	unsigned char mask = 1 << (irq & 7);
157 	unsigned int port = 0x4d0 + (irq >> 3);
158 	unsigned char val;
159 	static u16 eisa_irq_mask;
160 
161 	if (irq >= 16 || (1 << irq) & eisa_irq_mask)
162 		return;
163 
164 	eisa_irq_mask |= (1 << irq);
165 	printk(KERN_DEBUG "PCI: setting IRQ %u as level-triggered\n", irq);
166 	val = inb(port);
167 	if (!(val & mask)) {
168 		DBG(KERN_DEBUG " -> edge");
169 		outb(val | mask, port);
170 	}
171 }
172 
173 /*
174  * Common IRQ routing practice: nibbles in config space,
175  * offset by some magic constant.
176  */
177 static unsigned int read_config_nybble(struct pci_dev *router, unsigned offset, unsigned nr)
178 {
179 	u8 x;
180 	unsigned reg = offset + (nr >> 1);
181 
182 	pci_read_config_byte(router, reg, &x);
183 	return (nr & 1) ? (x >> 4) : (x & 0xf);
184 }
185 
186 static void write_config_nybble(struct pci_dev *router, unsigned offset,
187 	unsigned nr, unsigned int val)
188 {
189 	u8 x;
190 	unsigned reg = offset + (nr >> 1);
191 
192 	pci_read_config_byte(router, reg, &x);
193 	x = (nr & 1) ? ((x & 0x0f) | (val << 4)) : ((x & 0xf0) | val);
194 	pci_write_config_byte(router, reg, x);
195 }
196 
197 /*
198  * ALI pirq entries are damn ugly, and completely undocumented.
199  * This has been figured out from pirq tables, and it's not a pretty
200  * picture.
201  */
202 static int pirq_ali_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
203 {
204 	static const unsigned char irqmap[16] = { 0, 9, 3, 10, 4, 5, 7, 6, 1, 11, 0, 12, 0, 14, 0, 15 };
205 
206 	WARN_ON_ONCE(pirq > 16);
207 	return irqmap[read_config_nybble(router, 0x48, pirq-1)];
208 }
209 
210 static int pirq_ali_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
211 {
212 	static const unsigned char irqmap[16] = { 0, 8, 0, 2, 4, 5, 7, 6, 0, 1, 3, 9, 11, 0, 13, 15 };
213 	unsigned int val = irqmap[irq];
214 
215 	WARN_ON_ONCE(pirq > 16);
216 	if (val) {
217 		write_config_nybble(router, 0x48, pirq-1, val);
218 		return 1;
219 	}
220 	return 0;
221 }
222 
223 /*
224  * The Intel PIIX4 pirq rules are fairly simple: "pirq" is
225  * just a pointer to the config space.
226  */
227 static int pirq_piix_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
228 {
229 	u8 x;
230 
231 	pci_read_config_byte(router, pirq, &x);
232 	return (x < 16) ? x : 0;
233 }
234 
235 static int pirq_piix_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
236 {
237 	pci_write_config_byte(router, pirq, irq);
238 	return 1;
239 }
240 
241 /*
242  * The VIA pirq rules are nibble-based, like ALI,
243  * but without the ugly irq number munging.
244  * However, PIRQD is in the upper instead of lower 4 bits.
245  */
246 static int pirq_via_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
247 {
248 	return read_config_nybble(router, 0x55, pirq == 4 ? 5 : pirq);
249 }
250 
251 static int pirq_via_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
252 {
253 	write_config_nybble(router, 0x55, pirq == 4 ? 5 : pirq, irq);
254 	return 1;
255 }
256 
257 /*
258  * The VIA pirq rules are nibble-based, like ALI,
259  * but without the ugly irq number munging.
260  * However, for 82C586, nibble map is different .
261  */
262 static int pirq_via586_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
263 {
264 	static const unsigned int pirqmap[5] = { 3, 2, 5, 1, 1 };
265 
266 	WARN_ON_ONCE(pirq > 5);
267 	return read_config_nybble(router, 0x55, pirqmap[pirq-1]);
268 }
269 
270 static int pirq_via586_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
271 {
272 	static const unsigned int pirqmap[5] = { 3, 2, 5, 1, 1 };
273 
274 	WARN_ON_ONCE(pirq > 5);
275 	write_config_nybble(router, 0x55, pirqmap[pirq-1], irq);
276 	return 1;
277 }
278 
279 /*
280  * ITE 8330G pirq rules are nibble-based
281  * FIXME: pirqmap may be { 1, 0, 3, 2 },
282  * 	  2+3 are both mapped to irq 9 on my system
283  */
284 static int pirq_ite_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
285 {
286 	static const unsigned char pirqmap[4] = { 1, 0, 2, 3 };
287 
288 	WARN_ON_ONCE(pirq > 4);
289 	return read_config_nybble(router, 0x43, pirqmap[pirq-1]);
290 }
291 
292 static int pirq_ite_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
293 {
294 	static const unsigned char pirqmap[4] = { 1, 0, 2, 3 };
295 
296 	WARN_ON_ONCE(pirq > 4);
297 	write_config_nybble(router, 0x43, pirqmap[pirq-1], irq);
298 	return 1;
299 }
300 
301 /*
302  * OPTI: high four bits are nibble pointer..
303  * I wonder what the low bits do?
304  */
305 static int pirq_opti_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
306 {
307 	return read_config_nybble(router, 0xb8, pirq >> 4);
308 }
309 
310 static int pirq_opti_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
311 {
312 	write_config_nybble(router, 0xb8, pirq >> 4, irq);
313 	return 1;
314 }
315 
316 /*
317  * Cyrix: nibble offset 0x5C
318  * 0x5C bits 7:4 is INTB bits 3:0 is INTA
319  * 0x5D bits 7:4 is INTD bits 3:0 is INTC
320  */
321 static int pirq_cyrix_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
322 {
323 	return read_config_nybble(router, 0x5C, (pirq-1)^1);
324 }
325 
326 static int pirq_cyrix_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
327 {
328 	write_config_nybble(router, 0x5C, (pirq-1)^1, irq);
329 	return 1;
330 }
331 
332 /*
333  *	PIRQ routing for SiS 85C503 router used in several SiS chipsets.
334  *	We have to deal with the following issues here:
335  *	- vendors have different ideas about the meaning of link values
336  *	- some onboard devices (integrated in the chipset) have special
337  *	  links and are thus routed differently (i.e. not via PCI INTA-INTD)
338  *	- different revision of the router have a different layout for
339  *	  the routing registers, particularly for the onchip devices
340  *
341  *	For all routing registers the common thing is we have one byte
342  *	per routeable link which is defined as:
343  *		 bit 7      IRQ mapping enabled (0) or disabled (1)
344  *		 bits [6:4] reserved (sometimes used for onchip devices)
345  *		 bits [3:0] IRQ to map to
346  *		     allowed: 3-7, 9-12, 14-15
347  *		     reserved: 0, 1, 2, 8, 13
348  *
349  *	The config-space registers located at 0x41/0x42/0x43/0x44 are
350  *	always used to route the normal PCI INT A/B/C/D respectively.
351  *	Apparently there are systems implementing PCI routing table using
352  *	link values 0x01-0x04 and others using 0x41-0x44 for PCI INTA..D.
353  *	We try our best to handle both link mappings.
354  *
355  *	Currently (2003-05-21) it appears most SiS chipsets follow the
356  *	definition of routing registers from the SiS-5595 southbridge.
357  *	According to the SiS 5595 datasheets the revision id's of the
358  *	router (ISA-bridge) should be 0x01 or 0xb0.
359  *
360  *	Furthermore we've also seen lspci dumps with revision 0x00 and 0xb1.
361  *	Looks like these are used in a number of SiS 5xx/6xx/7xx chipsets.
362  *	They seem to work with the current routing code. However there is
363  *	some concern because of the two USB-OHCI HCs (original SiS 5595
364  *	had only one). YMMV.
365  *
366  *	Onchip routing for router rev-id 0x01/0xb0 and probably 0x00/0xb1:
367  *
368  *	0x61:	IDEIRQ:
369  *		bits [6:5] must be written 01
370  *		bit 4 channel-select primary (0), secondary (1)
371  *
372  *	0x62:	USBIRQ:
373  *		bit 6 OHCI function disabled (0), enabled (1)
374  *
375  *	0x6a:	ACPI/SCI IRQ: bits 4-6 reserved
376  *
377  *	0x7e:	Data Acq. Module IRQ - bits 4-6 reserved
378  *
379  *	We support USBIRQ (in addition to INTA-INTD) and keep the
380  *	IDE, ACPI and DAQ routing untouched as set by the BIOS.
381  *
382  *	Currently the only reported exception is the new SiS 65x chipset
383  *	which includes the SiS 69x southbridge. Here we have the 85C503
384  *	router revision 0x04 and there are changes in the register layout
385  *	mostly related to the different USB HCs with USB 2.0 support.
386  *
387  *	Onchip routing for router rev-id 0x04 (try-and-error observation)
388  *
389  *	0x60/0x61/0x62/0x63:	1xEHCI and 3xOHCI (companion) USB-HCs
390  *				bit 6-4 are probably unused, not like 5595
391  */
392 
393 #define PIRQ_SIS_IRQ_MASK	0x0f
394 #define PIRQ_SIS_IRQ_DISABLE	0x80
395 #define PIRQ_SIS_USB_ENABLE	0x40
396 
397 static int pirq_sis_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
398 {
399 	u8 x;
400 	int reg;
401 
402 	reg = pirq;
403 	if (reg >= 0x01 && reg <= 0x04)
404 		reg += 0x40;
405 	pci_read_config_byte(router, reg, &x);
406 	return (x & PIRQ_SIS_IRQ_DISABLE) ? 0 : (x & PIRQ_SIS_IRQ_MASK);
407 }
408 
409 static int pirq_sis_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
410 {
411 	u8 x;
412 	int reg;
413 
414 	reg = pirq;
415 	if (reg >= 0x01 && reg <= 0x04)
416 		reg += 0x40;
417 	pci_read_config_byte(router, reg, &x);
418 	x &= ~(PIRQ_SIS_IRQ_MASK | PIRQ_SIS_IRQ_DISABLE);
419 	x |= irq ? irq: PIRQ_SIS_IRQ_DISABLE;
420 	pci_write_config_byte(router, reg, x);
421 	return 1;
422 }
423 
424 
425 /*
426  * VLSI: nibble offset 0x74 - educated guess due to routing table and
427  *       config space of VLSI 82C534 PCI-bridge/router (1004:0102)
428  *       Tested on HP OmniBook 800 covering PIRQ 1, 2, 4, 8 for onboard
429  *       devices, PIRQ 3 for non-pci(!) soundchip and (untested) PIRQ 6
430  *       for the busbridge to the docking station.
431  */
432 
433 static int pirq_vlsi_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
434 {
435 	WARN_ON_ONCE(pirq >= 9);
436 	if (pirq > 8) {
437 		dev_info(&dev->dev, "VLSI router PIRQ escape (%d)\n", pirq);
438 		return 0;
439 	}
440 	return read_config_nybble(router, 0x74, pirq-1);
441 }
442 
443 static int pirq_vlsi_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
444 {
445 	WARN_ON_ONCE(pirq >= 9);
446 	if (pirq > 8) {
447 		dev_info(&dev->dev, "VLSI router PIRQ escape (%d)\n", pirq);
448 		return 0;
449 	}
450 	write_config_nybble(router, 0x74, pirq-1, irq);
451 	return 1;
452 }
453 
454 /*
455  * ServerWorks: PCI interrupts mapped to system IRQ lines through Index
456  * and Redirect I/O registers (0x0c00 and 0x0c01).  The Index register
457  * format is (PCIIRQ## | 0x10), e.g.: PCIIRQ10=0x1a.  The Redirect
458  * register is a straight binary coding of desired PIC IRQ (low nibble).
459  *
460  * The 'link' value in the PIRQ table is already in the correct format
461  * for the Index register.  There are some special index values:
462  * 0x00 for ACPI (SCI), 0x01 for USB, 0x02 for IDE0, 0x04 for IDE1,
463  * and 0x03 for SMBus.
464  */
465 static int pirq_serverworks_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
466 {
467 	outb(pirq, 0xc00);
468 	return inb(0xc01) & 0xf;
469 }
470 
471 static int pirq_serverworks_set(struct pci_dev *router, struct pci_dev *dev,
472 	int pirq, int irq)
473 {
474 	outb(pirq, 0xc00);
475 	outb(irq, 0xc01);
476 	return 1;
477 }
478 
479 /* Support for AMD756 PCI IRQ Routing
480  * Jhon H. Caicedo <jhcaiced@osso.org.co>
481  * Jun/21/2001 0.2.0 Release, fixed to use "nybble" functions... (jhcaiced)
482  * Jun/19/2001 Alpha Release 0.1.0 (jhcaiced)
483  * The AMD756 pirq rules are nibble-based
484  * offset 0x56 0-3 PIRQA  4-7  PIRQB
485  * offset 0x57 0-3 PIRQC  4-7  PIRQD
486  */
487 static int pirq_amd756_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
488 {
489 	u8 irq;
490 	irq = 0;
491 	if (pirq <= 4)
492 		irq = read_config_nybble(router, 0x56, pirq - 1);
493 	dev_info(&dev->dev,
494 		 "AMD756: dev [%04x:%04x], router PIRQ %d get IRQ %d\n",
495 		 dev->vendor, dev->device, pirq, irq);
496 	return irq;
497 }
498 
499 static int pirq_amd756_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
500 {
501 	dev_info(&dev->dev,
502 		 "AMD756: dev [%04x:%04x], router PIRQ %d set IRQ %d\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 - 1, 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_TGP_LPC:
575 	case PCI_DEVICE_ID_INTEL_ESB2_0:
576 	case PCI_DEVICE_ID_INTEL_ICH8_0:
577 	case PCI_DEVICE_ID_INTEL_ICH8_1:
578 	case PCI_DEVICE_ID_INTEL_ICH8_2:
579 	case PCI_DEVICE_ID_INTEL_ICH8_3:
580 	case PCI_DEVICE_ID_INTEL_ICH8_4:
581 	case PCI_DEVICE_ID_INTEL_ICH9_0:
582 	case PCI_DEVICE_ID_INTEL_ICH9_1:
583 	case PCI_DEVICE_ID_INTEL_ICH9_2:
584 	case PCI_DEVICE_ID_INTEL_ICH9_3:
585 	case PCI_DEVICE_ID_INTEL_ICH9_4:
586 	case PCI_DEVICE_ID_INTEL_ICH9_5:
587 	case PCI_DEVICE_ID_INTEL_EP80579_0:
588 	case PCI_DEVICE_ID_INTEL_ICH10_0:
589 	case PCI_DEVICE_ID_INTEL_ICH10_1:
590 	case PCI_DEVICE_ID_INTEL_ICH10_2:
591 	case PCI_DEVICE_ID_INTEL_ICH10_3:
592 	case PCI_DEVICE_ID_INTEL_PATSBURG_LPC_0:
593 	case PCI_DEVICE_ID_INTEL_PATSBURG_LPC_1:
594 		r->name = "PIIX/ICH";
595 		r->get = pirq_piix_get;
596 		r->set = pirq_piix_set;
597 		return 1;
598 	}
599 
600 	if ((device >= PCI_DEVICE_ID_INTEL_5_3400_SERIES_LPC_MIN) &&
601 		(device <= PCI_DEVICE_ID_INTEL_5_3400_SERIES_LPC_MAX)) {
602 		r->name = "PIIX/ICH";
603 		r->get = pirq_piix_get;
604 		r->set = pirq_piix_set;
605 		return 1;
606 	}
607 
608 	if ((device >= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MIN) &&
609 		(device <= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MAX)) {
610 		r->name = "PIIX/ICH";
611 		r->get = pirq_piix_get;
612 		r->set = pirq_piix_set;
613 		return 1;
614 	}
615 	return 0;
616 }
617 
618 static __init int via_router_probe(struct irq_router *r,
619 				struct pci_dev *router, u16 device)
620 {
621 	/* FIXME: We should move some of the quirk fixup stuff here */
622 
623 	/*
624 	 * workarounds for some buggy BIOSes
625 	 */
626 	if (device == PCI_DEVICE_ID_VIA_82C586_0) {
627 		switch (router->device) {
628 		case PCI_DEVICE_ID_VIA_82C686:
629 			/*
630 			 * Asus k7m bios wrongly reports 82C686A
631 			 * as 586-compatible
632 			 */
633 			device = PCI_DEVICE_ID_VIA_82C686;
634 			break;
635 		case PCI_DEVICE_ID_VIA_8235:
636 			/**
637 			 * Asus a7v-x bios wrongly reports 8235
638 			 * as 586-compatible
639 			 */
640 			device = PCI_DEVICE_ID_VIA_8235;
641 			break;
642 		case PCI_DEVICE_ID_VIA_8237:
643 			/**
644 			 * Asus a7v600 bios wrongly reports 8237
645 			 * as 586-compatible
646 			 */
647 			device = PCI_DEVICE_ID_VIA_8237;
648 			break;
649 		}
650 	}
651 
652 	switch (device) {
653 	case PCI_DEVICE_ID_VIA_82C586_0:
654 		r->name = "VIA";
655 		r->get = pirq_via586_get;
656 		r->set = pirq_via586_set;
657 		return 1;
658 	case PCI_DEVICE_ID_VIA_82C596:
659 	case PCI_DEVICE_ID_VIA_82C686:
660 	case PCI_DEVICE_ID_VIA_8231:
661 	case PCI_DEVICE_ID_VIA_8233A:
662 	case PCI_DEVICE_ID_VIA_8235:
663 	case PCI_DEVICE_ID_VIA_8237:
664 		/* FIXME: add new ones for 8233/5 */
665 		r->name = "VIA";
666 		r->get = pirq_via_get;
667 		r->set = pirq_via_set;
668 		return 1;
669 	}
670 	return 0;
671 }
672 
673 static __init int vlsi_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
674 {
675 	switch (device) {
676 	case PCI_DEVICE_ID_VLSI_82C534:
677 		r->name = "VLSI 82C534";
678 		r->get = pirq_vlsi_get;
679 		r->set = pirq_vlsi_set;
680 		return 1;
681 	}
682 	return 0;
683 }
684 
685 
686 static __init int serverworks_router_probe(struct irq_router *r,
687 		struct pci_dev *router, u16 device)
688 {
689 	switch (device) {
690 	case PCI_DEVICE_ID_SERVERWORKS_OSB4:
691 	case PCI_DEVICE_ID_SERVERWORKS_CSB5:
692 		r->name = "ServerWorks";
693 		r->get = pirq_serverworks_get;
694 		r->set = pirq_serverworks_set;
695 		return 1;
696 	}
697 	return 0;
698 }
699 
700 static __init int sis_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
701 {
702 	if (device != PCI_DEVICE_ID_SI_503)
703 		return 0;
704 
705 	r->name = "SIS";
706 	r->get = pirq_sis_get;
707 	r->set = pirq_sis_set;
708 	return 1;
709 }
710 
711 static __init int cyrix_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
712 {
713 	switch (device) {
714 	case PCI_DEVICE_ID_CYRIX_5520:
715 		r->name = "NatSemi";
716 		r->get = pirq_cyrix_get;
717 		r->set = pirq_cyrix_set;
718 		return 1;
719 	}
720 	return 0;
721 }
722 
723 static __init int opti_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
724 {
725 	switch (device) {
726 	case PCI_DEVICE_ID_OPTI_82C700:
727 		r->name = "OPTI";
728 		r->get = pirq_opti_get;
729 		r->set = pirq_opti_set;
730 		return 1;
731 	}
732 	return 0;
733 }
734 
735 static __init int ite_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
736 {
737 	switch (device) {
738 	case PCI_DEVICE_ID_ITE_IT8330G_0:
739 		r->name = "ITE";
740 		r->get = pirq_ite_get;
741 		r->set = pirq_ite_set;
742 		return 1;
743 	}
744 	return 0;
745 }
746 
747 static __init int ali_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
748 {
749 	switch (device) {
750 	case PCI_DEVICE_ID_AL_M1533:
751 	case PCI_DEVICE_ID_AL_M1563:
752 		r->name = "ALI";
753 		r->get = pirq_ali_get;
754 		r->set = pirq_ali_set;
755 		return 1;
756 	}
757 	return 0;
758 }
759 
760 static __init int amd_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
761 {
762 	switch (device) {
763 	case PCI_DEVICE_ID_AMD_VIPER_740B:
764 		r->name = "AMD756";
765 		break;
766 	case PCI_DEVICE_ID_AMD_VIPER_7413:
767 		r->name = "AMD766";
768 		break;
769 	case PCI_DEVICE_ID_AMD_VIPER_7443:
770 		r->name = "AMD768";
771 		break;
772 	default:
773 		return 0;
774 	}
775 	r->get = pirq_amd756_get;
776 	r->set = pirq_amd756_set;
777 	return 1;
778 }
779 
780 static __init int pico_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
781 {
782 	switch (device) {
783 	case PCI_DEVICE_ID_PICOPOWER_PT86C523:
784 		r->name = "PicoPower PT86C523";
785 		r->get = pirq_pico_get;
786 		r->set = pirq_pico_set;
787 		return 1;
788 
789 	case PCI_DEVICE_ID_PICOPOWER_PT86C523BBP:
790 		r->name = "PicoPower PT86C523 rev. BB+";
791 		r->get = pirq_pico_get;
792 		r->set = pirq_pico_set;
793 		return 1;
794 	}
795 	return 0;
796 }
797 
798 static __initdata struct irq_router_handler pirq_routers[] = {
799 	{ PCI_VENDOR_ID_INTEL, intel_router_probe },
800 	{ PCI_VENDOR_ID_AL, ali_router_probe },
801 	{ PCI_VENDOR_ID_ITE, ite_router_probe },
802 	{ PCI_VENDOR_ID_VIA, via_router_probe },
803 	{ PCI_VENDOR_ID_OPTI, opti_router_probe },
804 	{ PCI_VENDOR_ID_SI, sis_router_probe },
805 	{ PCI_VENDOR_ID_CYRIX, cyrix_router_probe },
806 	{ PCI_VENDOR_ID_VLSI, vlsi_router_probe },
807 	{ PCI_VENDOR_ID_SERVERWORKS, serverworks_router_probe },
808 	{ PCI_VENDOR_ID_AMD, amd_router_probe },
809 	{ PCI_VENDOR_ID_PICOPOWER, pico_router_probe },
810 	/* Someone with docs needs to add the ATI Radeon IGP */
811 	{ 0, NULL }
812 };
813 static struct irq_router pirq_router;
814 static struct pci_dev *pirq_router_dev;
815 
816 
817 /*
818  *	FIXME: should we have an option to say "generic for
819  *	chipset" ?
820  */
821 
822 static void __init pirq_find_router(struct irq_router *r)
823 {
824 	struct irq_routing_table *rt = pirq_table;
825 	struct irq_router_handler *h;
826 
827 #ifdef CONFIG_PCI_BIOS
828 	if (!rt->signature) {
829 		printk(KERN_INFO "PCI: Using BIOS for IRQ routing\n");
830 		r->set = pirq_bios_set;
831 		r->name = "BIOS";
832 		return;
833 	}
834 #endif
835 
836 	/* Default unless a driver reloads it */
837 	r->name = "default";
838 	r->get = NULL;
839 	r->set = NULL;
840 
841 	DBG(KERN_DEBUG "PCI: Attempting to find IRQ router for [%04x:%04x]\n",
842 	    rt->rtr_vendor, rt->rtr_device);
843 
844 	pirq_router_dev = pci_get_bus_and_slot(rt->rtr_bus, rt->rtr_devfn);
845 	if (!pirq_router_dev) {
846 		DBG(KERN_DEBUG "PCI: Interrupt router not found at "
847 			"%02x:%02x\n", rt->rtr_bus, rt->rtr_devfn);
848 		return;
849 	}
850 
851 	for (h = pirq_routers; h->vendor; h++) {
852 		/* First look for a router match */
853 		if (rt->rtr_vendor == h->vendor &&
854 			h->probe(r, pirq_router_dev, rt->rtr_device))
855 			break;
856 		/* Fall back to a device match */
857 		if (pirq_router_dev->vendor == h->vendor &&
858 			h->probe(r, pirq_router_dev, pirq_router_dev->device))
859 			break;
860 	}
861 	dev_info(&pirq_router_dev->dev, "%s IRQ router [%04x:%04x]\n",
862 		 pirq_router.name,
863 		 pirq_router_dev->vendor, pirq_router_dev->device);
864 
865 	/* The device remains referenced for the kernel lifetime */
866 }
867 
868 static struct irq_info *pirq_get_info(struct pci_dev *dev)
869 {
870 	struct irq_routing_table *rt = pirq_table;
871 	int entries = (rt->size - sizeof(struct irq_routing_table)) /
872 		sizeof(struct irq_info);
873 	struct irq_info *info;
874 
875 	for (info = rt->slots; entries--; info++)
876 		if (info->bus == dev->bus->number &&
877 			PCI_SLOT(info->devfn) == PCI_SLOT(dev->devfn))
878 			return info;
879 	return NULL;
880 }
881 
882 static int pcibios_lookup_irq(struct pci_dev *dev, int assign)
883 {
884 	u8 pin;
885 	struct irq_info *info;
886 	int i, pirq, newirq;
887 	int irq = 0;
888 	u32 mask;
889 	struct irq_router *r = &pirq_router;
890 	struct pci_dev *dev2 = NULL;
891 	char *msg = NULL;
892 
893 	/* Find IRQ pin */
894 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
895 	if (!pin) {
896 		dev_dbg(&dev->dev, "no interrupt pin\n");
897 		return 0;
898 	}
899 
900 	if (io_apic_assign_pci_irqs)
901 		return 0;
902 
903 	/* Find IRQ routing entry */
904 
905 	if (!pirq_table)
906 		return 0;
907 
908 	info = pirq_get_info(dev);
909 	if (!info) {
910 		dev_dbg(&dev->dev, "PCI INT %c not found in routing table\n",
911 			'A' + pin - 1);
912 		return 0;
913 	}
914 	pirq = info->irq[pin - 1].link;
915 	mask = info->irq[pin - 1].bitmap;
916 	if (!pirq) {
917 		dev_dbg(&dev->dev, "PCI INT %c not routed\n", 'A' + pin - 1);
918 		return 0;
919 	}
920 	dev_dbg(&dev->dev, "PCI INT %c -> PIRQ %02x, mask %04x, excl %04x",
921 		'A' + pin - 1, pirq, mask, pirq_table->exclusive_irqs);
922 	mask &= pcibios_irq_mask;
923 
924 	/* Work around broken HP Pavilion Notebooks which assign USB to
925 	   IRQ 9 even though it is actually wired to IRQ 11 */
926 
927 	if (broken_hp_bios_irq9 && pirq == 0x59 && dev->irq == 9) {
928 		dev->irq = 11;
929 		pci_write_config_byte(dev, PCI_INTERRUPT_LINE, 11);
930 		r->set(pirq_router_dev, dev, pirq, 11);
931 	}
932 
933 	/* same for Acer Travelmate 360, but with CB and irq 11 -> 10 */
934 	if (acer_tm360_irqrouting && dev->irq == 11 &&
935 		dev->vendor == PCI_VENDOR_ID_O2) {
936 		pirq = 0x68;
937 		mask = 0x400;
938 		dev->irq = r->get(pirq_router_dev, dev, pirq);
939 		pci_write_config_byte(dev, PCI_INTERRUPT_LINE, dev->irq);
940 	}
941 
942 	/*
943 	 * Find the best IRQ to assign: use the one
944 	 * reported by the device if possible.
945 	 */
946 	newirq = dev->irq;
947 	if (newirq && !((1 << newirq) & mask)) {
948 		if (pci_probe & PCI_USE_PIRQ_MASK)
949 			newirq = 0;
950 		else
951 			dev_warn(&dev->dev, "IRQ %d doesn't match PIRQ mask "
952 				 "%#x; try pci=usepirqmask\n", newirq, mask);
953 	}
954 	if (!newirq && assign) {
955 		for (i = 0; i < 16; i++) {
956 			if (!(mask & (1 << i)))
957 				continue;
958 			if (pirq_penalty[i] < pirq_penalty[newirq] &&
959 				can_request_irq(i, IRQF_SHARED))
960 				newirq = i;
961 		}
962 	}
963 	dev_dbg(&dev->dev, "PCI INT %c -> newirq %d", 'A' + pin - 1, newirq);
964 
965 	/* Check if it is hardcoded */
966 	if ((pirq & 0xf0) == 0xf0) {
967 		irq = pirq & 0xf;
968 		msg = "hardcoded";
969 	} else if (r->get && (irq = r->get(pirq_router_dev, dev, pirq)) && \
970 	((!(pci_probe & PCI_USE_PIRQ_MASK)) || ((1 << irq) & mask))) {
971 		msg = "found";
972 		eisa_set_level_irq(irq);
973 	} else if (newirq && r->set &&
974 		(dev->class >> 8) != PCI_CLASS_DISPLAY_VGA) {
975 		if (r->set(pirq_router_dev, dev, pirq, newirq)) {
976 			eisa_set_level_irq(newirq);
977 			msg = "assigned";
978 			irq = newirq;
979 		}
980 	}
981 
982 	if (!irq) {
983 		if (newirq && mask == (1 << newirq)) {
984 			msg = "guessed";
985 			irq = newirq;
986 		} else {
987 			dev_dbg(&dev->dev, "can't route interrupt\n");
988 			return 0;
989 		}
990 	}
991 	dev_info(&dev->dev, "%s PCI INT %c -> IRQ %d\n", msg, 'A' + pin - 1, irq);
992 
993 	/* Update IRQ for all devices with the same pirq value */
994 	for_each_pci_dev(dev2) {
995 		pci_read_config_byte(dev2, PCI_INTERRUPT_PIN, &pin);
996 		if (!pin)
997 			continue;
998 
999 		info = pirq_get_info(dev2);
1000 		if (!info)
1001 			continue;
1002 		if (info->irq[pin - 1].link == pirq) {
1003 			/*
1004 			 * We refuse to override the dev->irq
1005 			 * information. Give a warning!
1006 			 */
1007 			if (dev2->irq && dev2->irq != irq && \
1008 			(!(pci_probe & PCI_USE_PIRQ_MASK) || \
1009 			((1 << dev2->irq) & mask))) {
1010 #ifndef CONFIG_PCI_MSI
1011 				dev_info(&dev2->dev, "IRQ routing conflict: "
1012 					 "have IRQ %d, want IRQ %d\n",
1013 					 dev2->irq, irq);
1014 #endif
1015 				continue;
1016 			}
1017 			dev2->irq = irq;
1018 			pirq_penalty[irq]++;
1019 			if (dev != dev2)
1020 				dev_info(&dev->dev, "sharing IRQ %d with %s\n",
1021 					 irq, pci_name(dev2));
1022 		}
1023 	}
1024 	return 1;
1025 }
1026 
1027 void __init pcibios_fixup_irqs(void)
1028 {
1029 	struct pci_dev *dev = NULL;
1030 	u8 pin;
1031 
1032 	DBG(KERN_DEBUG "PCI: IRQ fixup\n");
1033 	for_each_pci_dev(dev) {
1034 		/*
1035 		 * If the BIOS has set an out of range IRQ number, just
1036 		 * ignore it.  Also keep track of which IRQ's are
1037 		 * already in use.
1038 		 */
1039 		if (dev->irq >= 16) {
1040 			dev_dbg(&dev->dev, "ignoring bogus IRQ %d\n", dev->irq);
1041 			dev->irq = 0;
1042 		}
1043 		/*
1044 		 * If the IRQ is already assigned to a PCI device,
1045 		 * ignore its ISA use penalty
1046 		 */
1047 		if (pirq_penalty[dev->irq] >= 100 &&
1048 				pirq_penalty[dev->irq] < 100000)
1049 			pirq_penalty[dev->irq] = 0;
1050 		pirq_penalty[dev->irq]++;
1051 	}
1052 
1053 	if (io_apic_assign_pci_irqs)
1054 		return;
1055 
1056 	dev = NULL;
1057 	for_each_pci_dev(dev) {
1058 		pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
1059 		if (!pin)
1060 			continue;
1061 
1062 		/*
1063 		 * Still no IRQ? Try to lookup one...
1064 		 */
1065 		if (!dev->irq)
1066 			pcibios_lookup_irq(dev, 0);
1067 	}
1068 }
1069 
1070 /*
1071  * Work around broken HP Pavilion Notebooks which assign USB to
1072  * IRQ 9 even though it is actually wired to IRQ 11
1073  */
1074 static int __init fix_broken_hp_bios_irq9(const struct dmi_system_id *d)
1075 {
1076 	if (!broken_hp_bios_irq9) {
1077 		broken_hp_bios_irq9 = 1;
1078 		printk(KERN_INFO "%s detected - fixing broken IRQ routing\n",
1079 			d->ident);
1080 	}
1081 	return 0;
1082 }
1083 
1084 /*
1085  * Work around broken Acer TravelMate 360 Notebooks which assign
1086  * Cardbus to IRQ 11 even though it is actually wired to IRQ 10
1087  */
1088 static int __init fix_acer_tm360_irqrouting(const struct dmi_system_id *d)
1089 {
1090 	if (!acer_tm360_irqrouting) {
1091 		acer_tm360_irqrouting = 1;
1092 		printk(KERN_INFO "%s detected - fixing broken IRQ routing\n",
1093 			d->ident);
1094 	}
1095 	return 0;
1096 }
1097 
1098 static struct dmi_system_id __initdata pciirq_dmi_table[] = {
1099 	{
1100 		.callback = fix_broken_hp_bios_irq9,
1101 		.ident = "HP Pavilion N5400 Series Laptop",
1102 		.matches = {
1103 			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1104 			DMI_MATCH(DMI_BIOS_VERSION, "GE.M1.03"),
1105 			DMI_MATCH(DMI_PRODUCT_VERSION,
1106 				"HP Pavilion Notebook Model GE"),
1107 			DMI_MATCH(DMI_BOARD_VERSION, "OmniBook N32N-736"),
1108 		},
1109 	},
1110 	{
1111 		.callback = fix_acer_tm360_irqrouting,
1112 		.ident = "Acer TravelMate 36x Laptop",
1113 		.matches = {
1114 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1115 			DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 360"),
1116 		},
1117 	},
1118 	{ }
1119 };
1120 
1121 void __init pcibios_irq_init(void)
1122 {
1123 	DBG(KERN_DEBUG "PCI: IRQ init\n");
1124 
1125 	if (raw_pci_ops == NULL)
1126 		return;
1127 
1128 	dmi_check_system(pciirq_dmi_table);
1129 
1130 	pirq_table = pirq_find_routing_table();
1131 
1132 #ifdef CONFIG_PCI_BIOS
1133 	if (!pirq_table && (pci_probe & PCI_BIOS_IRQ_SCAN))
1134 		pirq_table = pcibios_get_irq_routing_table();
1135 #endif
1136 	if (pirq_table) {
1137 		pirq_peer_trick();
1138 		pirq_find_router(&pirq_router);
1139 		if (pirq_table->exclusive_irqs) {
1140 			int i;
1141 			for (i = 0; i < 16; i++)
1142 				if (!(pirq_table->exclusive_irqs & (1 << i)))
1143 					pirq_penalty[i] += 100;
1144 		}
1145 		/*
1146 		 * If we're using the I/O APIC, avoid using the PCI IRQ
1147 		 * routing table
1148 		 */
1149 		if (io_apic_assign_pci_irqs)
1150 			pirq_table = NULL;
1151 	}
1152 
1153 	x86_init.pci.fixup_irqs();
1154 
1155 	if (io_apic_assign_pci_irqs && pci_routeirq) {
1156 		struct pci_dev *dev = NULL;
1157 		/*
1158 		 * PCI IRQ routing is set up by pci_enable_device(), but we
1159 		 * also do it here in case there are still broken drivers that
1160 		 * don't use pci_enable_device().
1161 		 */
1162 		printk(KERN_INFO "PCI: Routing PCI interrupts for all devices because \"pci=routeirq\" specified\n");
1163 		for_each_pci_dev(dev)
1164 			pirq_enable_irq(dev);
1165 	}
1166 }
1167 
1168 static void pirq_penalize_isa_irq(int irq, int active)
1169 {
1170 	/*
1171 	 *  If any ISAPnP device reports an IRQ in its list of possible
1172 	 *  IRQ's, we try to avoid assigning it to PCI devices.
1173 	 */
1174 	if (irq < 16) {
1175 		if (active)
1176 			pirq_penalty[irq] += 1000;
1177 		else
1178 			pirq_penalty[irq] += 100;
1179 	}
1180 }
1181 
1182 void pcibios_penalize_isa_irq(int irq, int active)
1183 {
1184 #ifdef CONFIG_ACPI
1185 	if (!acpi_noirq)
1186 		acpi_penalize_isa_irq(irq, active);
1187 	else
1188 #endif
1189 		pirq_penalize_isa_irq(irq, active);
1190 }
1191 
1192 static int pirq_enable_irq(struct pci_dev *dev)
1193 {
1194 	u8 pin;
1195 
1196 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
1197 	if (pin && !pcibios_lookup_irq(dev, 1)) {
1198 		char *msg = "";
1199 
1200 		if (!io_apic_assign_pci_irqs && dev->irq)
1201 			return 0;
1202 
1203 		if (io_apic_assign_pci_irqs) {
1204 #ifdef CONFIG_X86_IO_APIC
1205 			struct pci_dev *temp_dev;
1206 			int irq;
1207 			struct io_apic_irq_attr irq_attr;
1208 
1209 			irq = IO_APIC_get_PCI_irq_vector(dev->bus->number,
1210 						PCI_SLOT(dev->devfn),
1211 						pin - 1, &irq_attr);
1212 			/*
1213 			 * Busses behind bridges are typically not listed in the MP-table.
1214 			 * In this case we have to look up the IRQ based on the parent bus,
1215 			 * parent slot, and pin number. The SMP code detects such bridged
1216 			 * busses itself so we should get into this branch reliably.
1217 			 */
1218 			temp_dev = dev;
1219 			while (irq < 0 && dev->bus->parent) { /* go back to the bridge */
1220 				struct pci_dev *bridge = dev->bus->self;
1221 
1222 				pin = pci_swizzle_interrupt_pin(dev, pin);
1223 				irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
1224 						PCI_SLOT(bridge->devfn),
1225 						pin - 1, &irq_attr);
1226 				if (irq >= 0)
1227 					dev_warn(&dev->dev, "using bridge %s "
1228 						 "INT %c to get IRQ %d\n",
1229 						 pci_name(bridge), 'A' + pin - 1,
1230 						 irq);
1231 				dev = bridge;
1232 			}
1233 			dev = temp_dev;
1234 			if (irq >= 0) {
1235 				io_apic_set_pci_routing(&dev->dev, irq,
1236 							 &irq_attr);
1237 				dev->irq = irq;
1238 				dev_info(&dev->dev, "PCI->APIC IRQ transform: "
1239 					 "INT %c -> IRQ %d\n", 'A' + pin - 1, irq);
1240 				return 0;
1241 			} else
1242 				msg = "; probably buggy MP table";
1243 #endif
1244 		} else if (pci_probe & PCI_BIOS_IRQ_SCAN)
1245 			msg = "";
1246 		else
1247 			msg = "; please try using pci=biosirq";
1248 
1249 		/*
1250 		 * With IDE legacy devices the IRQ lookup failure is not
1251 		 * a problem..
1252 		 */
1253 		if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
1254 				!(dev->class & 0x5))
1255 			return 0;
1256 
1257 		dev_warn(&dev->dev, "can't find IRQ for PCI INT %c%s\n",
1258 			 'A' + pin - 1, msg);
1259 	}
1260 	return 0;
1261 }
1262