1/*-
2 * Copyright (c) 1997, Stefan Esser <se@freebsd.org>
3 * Copyright (c) 2000, Michael Smith <msmith@freebsd.org>
4 * Copyright (c) 2000, BSDi
5 * Copyright (c) 2004, John Baldwin <jhb@FreeBSD.org>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice unmodified, this list of conditions, and the following
13 * disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD: head/sys/i386/pci/pci_pir.c 282274 2015-04-30 15:48:48Z jhb $");
32
33#include <sys/param.h>
34#include <sys/systm.h>
35#include <sys/bus.h>
36#include <sys/kernel.h>
37#include <sys/malloc.h>
38#include <sys/module.h>
39#include <sys/sysctl.h>
40#include <vm/vm.h>
41#include <vm/pmap.h>
42#include <vm/vm_param.h>
43#include <machine/md_var.h>
44#include <dev/pci/pcivar.h>
45#include <dev/pci/pcireg.h>
46#include <machine/pci_cfgreg.h>
47#include <machine/segments.h>
48#include <machine/pc/bios.h>
49
50#define NUM_ISA_INTERRUPTS 16
51
52/*
53 * A link device. Loosely based on the ACPI PCI link device. This doesn't
54 * try to support priorities for different ISA interrupts.
55 */
56struct pci_link {
57 TAILQ_ENTRY(pci_link) pl_links;
58 uint8_t pl_id;
59 uint8_t pl_irq;
60 uint16_t pl_irqmask;
61 int pl_references;
62 int pl_routed;
63};
64
65struct pci_link_lookup {
66 struct pci_link **pci_link_ptr;
67 int bus;
68 int device;
69 int pin;
70};
71
72struct pci_dev_lookup {
73 uint8_t link;
74 int bus;
75 int device;
76 int pin;
77};
78
79typedef void pir_entry_handler(struct PIR_entry *entry,
80 struct PIR_intpin* intpin, void *arg);
81
82static void pci_print_irqmask(u_int16_t irqs);
83static int pci_pir_biosroute(int bus, int device, int func, int pin,
84 int irq);
85static int pci_pir_choose_irq(struct pci_link *pci_link, int irqmask);
86static void pci_pir_create_links(struct PIR_entry *entry,
87 struct PIR_intpin *intpin, void *arg);
88static void pci_pir_dump_links(void);
89static struct pci_link *pci_pir_find_link(uint8_t link_id);
90static void pci_pir_find_link_handler(struct PIR_entry *entry,
91 struct PIR_intpin *intpin, void *arg);
92static void pci_pir_initial_irqs(struct PIR_entry *entry,
93 struct PIR_intpin *intpin, void *arg);
94static void pci_pir_parse(void);
95static uint8_t pci_pir_search_irq(int bus, int device, int pin);
96static int pci_pir_valid_irq(struct pci_link *pci_link, int irq);
97static void pci_pir_walk_table(pir_entry_handler *handler, void *arg);
98
99static MALLOC_DEFINE(M_PIR, "$PIR", "$PIR structures");
100
101static struct PIR_table *pci_route_table;
102static device_t pir_device;
103static int pci_route_count, pir_bios_irqs, pir_parsed;
104static TAILQ_HEAD(, pci_link) pci_links;
105static int pir_interrupt_weight[NUM_ISA_INTERRUPTS];
106
107/* sysctl vars */
108SYSCTL_DECL(_hw_pci);
109
110/* XXX this likely should live in a header file */
111#ifdef PC98
112/* IRQs 3, 5, 7, 9, 10, 11, 12, 13 */
113#define PCI_IRQ_OVERRIDE_MASK 0x3e68
114#else
115/* IRQs 3, 4, 5, 6, 7, 9, 10, 11, 12, 14, 15 */
116#define PCI_IRQ_OVERRIDE_MASK 0xdef8
117#endif
118
119static uint32_t pci_irq_override_mask = PCI_IRQ_OVERRIDE_MASK;
120SYSCTL_INT(_hw_pci, OID_AUTO, irq_override_mask, CTLFLAG_RDTUN,
121 &pci_irq_override_mask, PCI_IRQ_OVERRIDE_MASK,
122 "Mask of allowed irqs to try to route when it has no good clue about\n"
123 "which irqs it should use.");
124
125/*
126 * Look for the interrupt routing table.
127 *
128 * We use PCI BIOS's PIR table if it's available. $PIR is the standard way
129 * to do this. Sadly, some machines are not standards conforming and have
130 * _PIR instead. We shrug and cope by looking for both.
131 */
132void
133pci_pir_open(void)
134{
135 struct PIR_table *pt;
136 uint32_t sigaddr;
137 int i;
138 uint8_t ck, *cv;
139
140 /* Don't try if we've already found a table. */
141 if (pci_route_table != NULL)
142 return;
143
144 /* Look for $PIR and then _PIR. */
145 sigaddr = bios_sigsearch(0, "$PIR", 4, 16, 0);
146 if (sigaddr == 0)
147 sigaddr = bios_sigsearch(0, "_PIR", 4, 16, 0);
148 if (sigaddr == 0)
149 return;
150
151 /* If we found something, check the checksum and length. */
152 /* XXX - Use pmap_mapdev()? */
153 pt = (struct PIR_table *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
154 if (pt->pt_header.ph_length <= sizeof(struct PIR_header))
155 return;
156 for (cv = (u_int8_t *)pt, ck = 0, i = 0;
157 i < (pt->pt_header.ph_length); i++)
158 ck += cv[i];
159 if (ck != 0)
160 return;
161
162 /* Ok, we've got a valid table. */
163 pci_route_table = pt;
164 pci_route_count = (pt->pt_header.ph_length -
165 sizeof(struct PIR_header)) /
166 sizeof(struct PIR_entry);
167}
168
169/*
170 * Find the pci_link structure for a given link ID.
171 */
172static struct pci_link *
173pci_pir_find_link(uint8_t link_id)
174{
175 struct pci_link *pci_link;
176
177 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
178 if (pci_link->pl_id == link_id)
179 return (pci_link);
180 }
181 return (NULL);
182}
183
184/*
185 * Find the link device associated with a PCI device in the table.
186 */
187static void
188pci_pir_find_link_handler(struct PIR_entry *entry, struct PIR_intpin *intpin,
189 void *arg)
190{
191 struct pci_link_lookup *lookup;
192
193 lookup = (struct pci_link_lookup *)arg;
194 if (entry->pe_bus == lookup->bus &&
195 entry->pe_device == lookup->device &&
196 intpin - entry->pe_intpin == lookup->pin)
197 *lookup->pci_link_ptr = pci_pir_find_link(intpin->link);
198}
199
200/*
201 * Check to see if a possible IRQ setting is valid.
202 */
203static int
204pci_pir_valid_irq(struct pci_link *pci_link, int irq)
205{
206
207 if (!PCI_INTERRUPT_VALID(irq))
208 return (0);
209 return (pci_link->pl_irqmask & (1 << irq));
210}
211
212/*
213 * Walk the $PIR executing the worker function for each valid intpin entry
214 * in the table. The handler is passed a pointer to both the entry and
215 * the intpin in the entry.
216 */
217static void
218pci_pir_walk_table(pir_entry_handler *handler, void *arg)
219{
220 struct PIR_entry *entry;
221 struct PIR_intpin *intpin;
222 int i, pin;
223
224 entry = &pci_route_table->pt_entry[0];
225 for (i = 0; i < pci_route_count; i++, entry++) {
226 intpin = &entry->pe_intpin[0];
227 for (pin = 0; pin < 4; pin++, intpin++)
228 if (intpin->link != 0)
229 handler(entry, intpin, arg);
230 }
231}
232
233static void
234pci_pir_create_links(struct PIR_entry *entry, struct PIR_intpin *intpin,
235 void *arg)
236{
237 struct pci_link *pci_link;
238
239 pci_link = pci_pir_find_link(intpin->link);
240 if (pci_link != NULL) {
241 pci_link->pl_references++;
242 if (intpin->irqs != pci_link->pl_irqmask) {
243 if (bootverbose)
244 printf(
245 "$PIR: Entry %d.%d.INT%c has different mask for link %#x, merging\n",
246 entry->pe_bus, entry->pe_device,
247 (intpin - entry->pe_intpin) + 'A',
248 pci_link->pl_id);
249 pci_link->pl_irqmask &= intpin->irqs;
250 }
251 } else {
252 pci_link = malloc(sizeof(struct pci_link), M_PIR, M_WAITOK);
253 pci_link->pl_id = intpin->link;
254 pci_link->pl_irqmask = intpin->irqs;
255 pci_link->pl_irq = PCI_INVALID_IRQ;
256 pci_link->pl_references = 1;
257 pci_link->pl_routed = 0;
258 TAILQ_INSERT_TAIL(&pci_links, pci_link, pl_links);
259 }
260}
261
262/*
263 * Look to see if any of the function on the PCI device at bus/device have
264 * an interrupt routed to intpin 'pin' by the BIOS.
265 */
266static uint8_t
267pci_pir_search_irq(int bus, int device, int pin)
268{
269 uint32_t value;
270 uint8_t func, maxfunc;
271
272 /* See if we have a valid device at function 0. */
273 value = pci_cfgregread(bus, device, 0, PCIR_HDRTYPE, 1);
274 if ((value & PCIM_HDRTYPE) > PCI_MAXHDRTYPE)
275 return (PCI_INVALID_IRQ);
276 if (value & PCIM_MFDEV)
277 maxfunc = PCI_FUNCMAX;
278 else
279 maxfunc = 0;
280
281 /* Scan all possible functions at this device. */
282 for (func = 0; func <= maxfunc; func++) {
283 value = pci_cfgregread(bus, device, func, PCIR_DEVVENDOR, 4);
284 if (value == 0xffffffff)
285 continue;
286 value = pci_cfgregread(bus, device, func, PCIR_INTPIN, 1);
287
288 /*
289 * See if it uses the pin in question. Note that the passed
290 * in pin uses 0 for A, .. 3 for D whereas the intpin
291 * register uses 0 for no interrupt, 1 for A, .. 4 for D.
292 */
293 if (value != pin + 1)
294 continue;
295 value = pci_cfgregread(bus, device, func, PCIR_INTLINE, 1);
296 if (bootverbose)
297 printf(
298 "$PIR: Found matching pin for %d.%d.INT%c at func %d: %d\n",
299 bus, device, pin + 'A', func, value);
300 if (value != PCI_INVALID_IRQ)
301 return (value);
302 }
303 return (PCI_INVALID_IRQ);
304}
305
306/*
307 * Try to initialize IRQ based on this device's IRQ.
308 */
309static void
310pci_pir_initial_irqs(struct PIR_entry *entry, struct PIR_intpin *intpin,
311 void *arg)
312{
313 struct pci_link *pci_link;
314 uint8_t irq, pin;
315
316 pin = intpin - entry->pe_intpin;
317 pci_link = pci_pir_find_link(intpin->link);
318 irq = pci_pir_search_irq(entry->pe_bus, entry->pe_device, pin);
319 if (irq == PCI_INVALID_IRQ || irq == pci_link->pl_irq)
320 return;
321
322 /* Don't trust any BIOS IRQs greater than 15. */
323 if (irq >= NUM_ISA_INTERRUPTS) {
324 printf(
325 "$PIR: Ignoring invalid BIOS IRQ %d from %d.%d.INT%c for link %#x\n",
326 irq, entry->pe_bus, entry->pe_device, pin + 'A',
327 pci_link->pl_id);
328 return;
329 }
330
331 /*
332 * If we don't have an IRQ for this link yet, then we trust the
333 * BIOS, even if it seems invalid from the $PIR entries.
334 */
335 if (pci_link->pl_irq == PCI_INVALID_IRQ) {
336 if (!pci_pir_valid_irq(pci_link, irq))
337 printf(
338 "$PIR: Using invalid BIOS IRQ %d from %d.%d.INT%c for link %#x\n",
339 irq, entry->pe_bus, entry->pe_device, pin + 'A',
340 pci_link->pl_id);
341 pci_link->pl_irq = irq;
342 pci_link->pl_routed = 1;
343 return;
344 }
345
346 /*
347 * We have an IRQ and it doesn't match the current IRQ for this
348 * link. If the new IRQ is invalid, then warn about it and ignore
349 * it. If the old IRQ is invalid and the new IRQ is valid, then
350 * prefer the new IRQ instead. If both IRQs are valid, then just
351 * use the first one. Note that if we ever get into this situation
352 * we are having to guess which setting the BIOS actually routed.
353 * Perhaps we should just give up instead.
354 */
355 if (!pci_pir_valid_irq(pci_link, irq)) {
356 printf(
357 "$PIR: BIOS IRQ %d for %d.%d.INT%c is not valid for link %#x\n",
358 irq, entry->pe_bus, entry->pe_device, pin + 'A',
359 pci_link->pl_id);
360 } else if (!pci_pir_valid_irq(pci_link, pci_link->pl_irq)) {
361 printf(
362"$PIR: Preferring valid BIOS IRQ %d from %d.%d.INT%c for link %#x to IRQ %d\n",
363 irq, entry->pe_bus, entry->pe_device, pin + 'A',
364 pci_link->pl_id, pci_link->pl_irq);
365 pci_link->pl_irq = irq;
366 pci_link->pl_routed = 1;
367 } else
368 printf(
369 "$PIR: BIOS IRQ %d for %d.%d.INT%c does not match link %#x irq %d\n",
370 irq, entry->pe_bus, entry->pe_device, pin + 'A',
371 pci_link->pl_id, pci_link->pl_irq);
372}
373
374/*
375 * Parse $PIR to enumerate link devices and attempt to determine their
376 * initial state. This could perhaps be cleaner if we had drivers for the
377 * various interrupt routers as they could read the initial IRQ for each
378 * link.
379 */
380static void
381pci_pir_parse(void)
382{
383 char tunable_buffer[64];
384 struct pci_link *pci_link;
385 int i, irq;
386
387 /* Only parse once. */
388 if (pir_parsed)
389 return;
390 pir_parsed = 1;
391
392 /* Enumerate link devices. */
393 TAILQ_INIT(&pci_links);
394 pci_pir_walk_table(pci_pir_create_links, NULL);
395 if (bootverbose) {
396 printf("$PIR: Links after initial probe:\n");
397 pci_pir_dump_links();
398 }
399
400 /*
401 * Check to see if the BIOS has already routed any of the links by
402 * checking each device connected to each link to see if it has a
403 * valid IRQ.
404 */
405 pci_pir_walk_table(pci_pir_initial_irqs, NULL);
406 if (bootverbose) {
407 printf("$PIR: Links after initial IRQ discovery:\n");
408 pci_pir_dump_links();
409 }
410
411 /*
412 * Allow the user to override the IRQ for a given link device. We
413 * allow invalid IRQs to be specified but warn about them. An IRQ
414 * of 255 or 0 clears any preset IRQ.
415 */
416 i = 0;
417 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
418 snprintf(tunable_buffer, sizeof(tunable_buffer),
419 "hw.pci.link.%#x.irq", pci_link->pl_id);
420 if (getenv_int(tunable_buffer, &irq) == 0)
421 continue;
422 if (irq == 0)
423 irq = PCI_INVALID_IRQ;
424 if (irq != PCI_INVALID_IRQ &&
425 !pci_pir_valid_irq(pci_link, irq) && bootverbose)
426 printf(
427 "$PIR: Warning, IRQ %d for link %#x is not listed as valid\n",
428 irq, pci_link->pl_id);
429 pci_link->pl_routed = 0;
430 pci_link->pl_irq = irq;
431 i = 1;
432 }
433 if (bootverbose && i) {
434 printf("$PIR: Links after tunable overrides:\n");
435 pci_pir_dump_links();
436 }
437
438 /*
439 * Build initial interrupt weights as well as bitmap of "known-good"
440 * IRQs that the BIOS has already used for PCI link devices.
441 */
442 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
443 if (!PCI_INTERRUPT_VALID(pci_link->pl_irq))
444 continue;
445 pir_bios_irqs |= 1 << pci_link->pl_irq;
446 pir_interrupt_weight[pci_link->pl_irq] +=
447 pci_link->pl_references;
448 }
449 if (bootverbose) {
450 printf("$PIR: IRQs used by BIOS: ");
451 pci_print_irqmask(pir_bios_irqs);
452 printf("\n");
453 printf("$PIR: Interrupt Weights:\n[ ");
454 for (i = 0; i < NUM_ISA_INTERRUPTS; i++)
455 printf(" %3d", i);
456 printf(" ]\n[ ");
457 for (i = 0; i < NUM_ISA_INTERRUPTS; i++)
458 printf(" %3d", pir_interrupt_weight[i]);
459 printf(" ]\n");
460 }
461}
462
463/*
464 * Use the PCI BIOS to route an interrupt for a given device.
465 *
466 * Input:
467 * AX = PCIBIOS_ROUTE_INTERRUPT
468 * BH = bus
469 * BL = device [7:3] / function [2:0]
470 * CH = IRQ
471 * CL = Interrupt Pin (0x0A = A, ... 0x0D = D)
472 */
473static int
474pci_pir_biosroute(int bus, int device, int func, int pin, int irq)
475{
476 struct bios_regs args;
477
478 args.eax = PCIBIOS_ROUTE_INTERRUPT;
479 args.ebx = (bus << 8) | (device << 3) | func;
480 args.ecx = (irq << 8) | (0xa + pin);
481 return (bios32(&args, PCIbios.ventry, GSEL(GCODE_SEL, SEL_KPL)));
482}
483
484
485/*
486 * Route a PCI interrupt using a link device from the $PIR.
487 */
488int
489pci_pir_route_interrupt(int bus, int device, int func, int pin)
490{
491 struct pci_link_lookup lookup;
492 struct pci_link *pci_link;
493 int error, irq;
494
495 if (pci_route_table == NULL)
496 return (PCI_INVALID_IRQ);
497
498 /* Lookup link device for this PCI device/pin. */
499 pci_link = NULL;
500 lookup.bus = bus;
501 lookup.device = device;
502 lookup.pin = pin - 1;
503 lookup.pci_link_ptr = &pci_link;
504 pci_pir_walk_table(pci_pir_find_link_handler, &lookup);
505 if (pci_link == NULL) {
506 printf("$PIR: No matching entry for %d.%d.INT%c\n", bus,
507 device, pin - 1 + 'A');
508 return (PCI_INVALID_IRQ);
509 }
510
511 /*
512 * Pick a new interrupt if we don't have one already. We look
513 * for an interrupt from several different sets. First, if
514 * this link only has one valid IRQ, use that. Second, we
515 * check the set of PCI only interrupts from the $PIR. Third,
516 * we check the set of known-good interrupts that the BIOS has
517 * already used. Lastly, we check the "all possible valid
518 * IRQs" set.
519 */
520 if (!PCI_INTERRUPT_VALID(pci_link->pl_irq)) {
521 if (pci_link->pl_irqmask != 0 && powerof2(pci_link->pl_irqmask))
522 irq = ffs(pci_link->pl_irqmask) - 1;
523 else
524 irq = pci_pir_choose_irq(pci_link,
525 pci_route_table->pt_header.ph_pci_irqs);
526 if (!PCI_INTERRUPT_VALID(irq))
527 irq = pci_pir_choose_irq(pci_link, pir_bios_irqs);
528 if (!PCI_INTERRUPT_VALID(irq))
529 irq = pci_pir_choose_irq(pci_link,
530 pci_irq_override_mask);
531 if (!PCI_INTERRUPT_VALID(irq)) {
532 if (bootverbose)
533 printf(
534 "$PIR: Failed to route interrupt for %d:%d INT%c\n",
535 bus, device, pin - 1 + 'A');
536 return (PCI_INVALID_IRQ);
537 }
538 pci_link->pl_irq = irq;
539 }
540
541 /* Ask the BIOS to route this IRQ if we haven't done so already. */
542 if (!pci_link->pl_routed) {
543 error = pci_pir_biosroute(bus, device, func, pin - 1,
544 pci_link->pl_irq);
545
546 /* Ignore errors when routing a unique interrupt. */
547 if (error && !powerof2(pci_link->pl_irqmask)) {
548 printf("$PIR: ROUTE_INTERRUPT failed.\n");
549 return (PCI_INVALID_IRQ);
550 }
551 pci_link->pl_routed = 1;
552
553 /* Ensure the interrupt is set to level/low trigger. */
554 KASSERT(pir_device != NULL, ("missing pir device"));
555 BUS_CONFIG_INTR(pir_device, pci_link->pl_irq,
556 INTR_TRIGGER_LEVEL, INTR_POLARITY_LOW);
557 }
558 if (bootverbose)
559 printf("$PIR: %d:%d INT%c routed to irq %d\n", bus, device,
560 pin - 1 + 'A', pci_link->pl_irq);
561 return (pci_link->pl_irq);
562}
563
564/*
565 * Try to pick an interrupt for the specified link from the interrupts
566 * set in the mask.
567 */
568static int
569pci_pir_choose_irq(struct pci_link *pci_link, int irqmask)
570{
571 int i, irq, realmask;
572
573 /* XXX: Need to have a #define of known bad IRQs to also mask out? */
574 realmask = pci_link->pl_irqmask & irqmask;
575 if (realmask == 0)
576 return (PCI_INVALID_IRQ);
577
578 /* Find IRQ with lowest weight. */
579 irq = PCI_INVALID_IRQ;
580 for (i = 0; i < NUM_ISA_INTERRUPTS; i++) {
581 if (!(realmask & 1 << i))
582 continue;
583 if (irq == PCI_INVALID_IRQ ||
584 pir_interrupt_weight[i] < pir_interrupt_weight[irq])
585 irq = i;
586 }
587 if (bootverbose && PCI_INTERRUPT_VALID(irq)) {
588 printf("$PIR: Found IRQ %d for link %#x from ", irq,
589 pci_link->pl_id);
590 pci_print_irqmask(realmask);
591 printf("\n");
592 }
593 return (irq);
594}
595
596static void
597pci_print_irqmask(u_int16_t irqs)
598{
599 int i, first;
600
601 if (irqs == 0) {
602 printf("none");
603 return;
604 }
605 first = 1;
606 for (i = 0; i < 16; i++, irqs >>= 1)
607 if (irqs & 1) {
608 if (!first)
609 printf(" ");
610 else
611 first = 0;
612 printf("%d", i);
613 }
614}
615
616/*
617 * Display link devices.
618 */
619static void
620pci_pir_dump_links(void)
621{
622 struct pci_link *pci_link;
623
624 printf("Link IRQ Rtd Ref IRQs\n");
625 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
626 printf("%#4x %3d %c %3d ", pci_link->pl_id,
627 pci_link->pl_irq, pci_link->pl_routed ? 'Y' : 'N',
628 pci_link->pl_references);
629 pci_print_irqmask(pci_link->pl_irqmask);
630 printf("\n");
631 }
632}
633
634/*
635 * See if any interrupts for a given PCI bus are routed in the PIR. Don't
636 * even bother looking if the BIOS doesn't support routing anyways. If we
637 * are probing a PCI-PCI bridge, then require_parse will be true and we should
638 * only succeed if a host-PCI bridge has already attached and parsed the PIR.
639 */
640int
641pci_pir_probe(int bus, int require_parse)
642{
643 int i;
644
645 if (pci_route_table == NULL || (require_parse && !pir_parsed))
646 return (0);
647 for (i = 0; i < pci_route_count; i++)
648 if (pci_route_table->pt_entry[i].pe_bus == bus)
649 return (1);
650 return (0);
651}
652
653/*
654 * The driver for the new-bus psuedo device pir0 for the $PIR table.
655 */
656
657static int
658pir_probe(device_t dev)
659{
660 char buf[64];
661
662 snprintf(buf, sizeof(buf), "PCI Interrupt Routing Table: %d Entries",
663 pci_route_count);
664 device_set_desc_copy(dev, buf);
665 return (0);
666}
667
668static int
669pir_attach(device_t dev)
670{
671
672 pci_pir_parse();
673 KASSERT(pir_device == NULL, ("Multiple pir devices"));
674 pir_device = dev;
675 return (0);
676}
677
678static void
679pir_resume_find_device(struct PIR_entry *entry, struct PIR_intpin *intpin,
680 void *arg)
681{
682 struct pci_dev_lookup *pd;
683
684 pd = (struct pci_dev_lookup *)arg;
685 if (intpin->link != pd->link || pd->bus != -1)
686 return;
687 pd->bus = entry->pe_bus;
688 pd->device = entry->pe_device;
689 pd->pin = intpin - entry->pe_intpin;
690}
691
692static int
693pir_resume(device_t dev)
694{
695 struct pci_dev_lookup pd;
696 struct pci_link *pci_link;
697 int error;
698
699 /* Ask the BIOS to re-route each link that was already routed. */
700 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
701 if (!PCI_INTERRUPT_VALID(pci_link->pl_irq)) {
702 KASSERT(!pci_link->pl_routed,
703 ("link %#x is routed but has invalid PCI IRQ",
704 pci_link->pl_id));
705 continue;
706 }
707 if (pci_link->pl_routed) {
708 pd.bus = -1;
709 pd.link = pci_link->pl_id;
710 pci_pir_walk_table(pir_resume_find_device, &pd);
711 KASSERT(pd.bus != -1,
712 ("did not find matching entry for link %#x in the $PIR table",
713 pci_link->pl_id));
714 if (bootverbose)
715 device_printf(dev,
716 "Using %d.%d.INT%c to route link %#x to IRQ %d\n",
717 pd.bus, pd.device, pd.pin + 'A',
718 pci_link->pl_id, pci_link->pl_irq);
719 error = pci_pir_biosroute(pd.bus, pd.device, 0, pd.pin,
720 pci_link->pl_irq);
721 if (error)
722 device_printf(dev,
723 "ROUTE_INTERRUPT on resume for link %#x failed.\n",
724 pci_link->pl_id);
725 }
726 }
727 return (0);
728}
729
730static device_method_t pir_methods[] = {
731 /* Device interface */
732 DEVMETHOD(device_probe, pir_probe),
733 DEVMETHOD(device_attach, pir_attach),
734 DEVMETHOD(device_resume, pir_resume),
735
736 { 0, 0 }
737};
738
739static driver_t pir_driver = {
740 "pir",
741 pir_methods,
742 1,
743};
744
745static devclass_t pir_devclass;
746
747DRIVER_MODULE(pir, legacy, pir_driver, pir_devclass, 0, 0);
2 * Copyright (c) 1997, Stefan Esser <se@freebsd.org>
3 * Copyright (c) 2000, Michael Smith <msmith@freebsd.org>
4 * Copyright (c) 2000, BSDi
5 * Copyright (c) 2004, John Baldwin <jhb@FreeBSD.org>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice unmodified, this list of conditions, and the following
13 * disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD: head/sys/i386/pci/pci_pir.c 282274 2015-04-30 15:48:48Z jhb $");
32
33#include <sys/param.h>
34#include <sys/systm.h>
35#include <sys/bus.h>
36#include <sys/kernel.h>
37#include <sys/malloc.h>
38#include <sys/module.h>
39#include <sys/sysctl.h>
40#include <vm/vm.h>
41#include <vm/pmap.h>
42#include <vm/vm_param.h>
43#include <machine/md_var.h>
44#include <dev/pci/pcivar.h>
45#include <dev/pci/pcireg.h>
46#include <machine/pci_cfgreg.h>
47#include <machine/segments.h>
48#include <machine/pc/bios.h>
49
50#define NUM_ISA_INTERRUPTS 16
51
52/*
53 * A link device. Loosely based on the ACPI PCI link device. This doesn't
54 * try to support priorities for different ISA interrupts.
55 */
56struct pci_link {
57 TAILQ_ENTRY(pci_link) pl_links;
58 uint8_t pl_id;
59 uint8_t pl_irq;
60 uint16_t pl_irqmask;
61 int pl_references;
62 int pl_routed;
63};
64
65struct pci_link_lookup {
66 struct pci_link **pci_link_ptr;
67 int bus;
68 int device;
69 int pin;
70};
71
72struct pci_dev_lookup {
73 uint8_t link;
74 int bus;
75 int device;
76 int pin;
77};
78
79typedef void pir_entry_handler(struct PIR_entry *entry,
80 struct PIR_intpin* intpin, void *arg);
81
82static void pci_print_irqmask(u_int16_t irqs);
83static int pci_pir_biosroute(int bus, int device, int func, int pin,
84 int irq);
85static int pci_pir_choose_irq(struct pci_link *pci_link, int irqmask);
86static void pci_pir_create_links(struct PIR_entry *entry,
87 struct PIR_intpin *intpin, void *arg);
88static void pci_pir_dump_links(void);
89static struct pci_link *pci_pir_find_link(uint8_t link_id);
90static void pci_pir_find_link_handler(struct PIR_entry *entry,
91 struct PIR_intpin *intpin, void *arg);
92static void pci_pir_initial_irqs(struct PIR_entry *entry,
93 struct PIR_intpin *intpin, void *arg);
94static void pci_pir_parse(void);
95static uint8_t pci_pir_search_irq(int bus, int device, int pin);
96static int pci_pir_valid_irq(struct pci_link *pci_link, int irq);
97static void pci_pir_walk_table(pir_entry_handler *handler, void *arg);
98
99static MALLOC_DEFINE(M_PIR, "$PIR", "$PIR structures");
100
101static struct PIR_table *pci_route_table;
102static device_t pir_device;
103static int pci_route_count, pir_bios_irqs, pir_parsed;
104static TAILQ_HEAD(, pci_link) pci_links;
105static int pir_interrupt_weight[NUM_ISA_INTERRUPTS];
106
107/* sysctl vars */
108SYSCTL_DECL(_hw_pci);
109
110/* XXX this likely should live in a header file */
111#ifdef PC98
112/* IRQs 3, 5, 7, 9, 10, 11, 12, 13 */
113#define PCI_IRQ_OVERRIDE_MASK 0x3e68
114#else
115/* IRQs 3, 4, 5, 6, 7, 9, 10, 11, 12, 14, 15 */
116#define PCI_IRQ_OVERRIDE_MASK 0xdef8
117#endif
118
119static uint32_t pci_irq_override_mask = PCI_IRQ_OVERRIDE_MASK;
120SYSCTL_INT(_hw_pci, OID_AUTO, irq_override_mask, CTLFLAG_RDTUN,
121 &pci_irq_override_mask, PCI_IRQ_OVERRIDE_MASK,
122 "Mask of allowed irqs to try to route when it has no good clue about\n"
123 "which irqs it should use.");
124
125/*
126 * Look for the interrupt routing table.
127 *
128 * We use PCI BIOS's PIR table if it's available. $PIR is the standard way
129 * to do this. Sadly, some machines are not standards conforming and have
130 * _PIR instead. We shrug and cope by looking for both.
131 */
132void
133pci_pir_open(void)
134{
135 struct PIR_table *pt;
136 uint32_t sigaddr;
137 int i;
138 uint8_t ck, *cv;
139
140 /* Don't try if we've already found a table. */
141 if (pci_route_table != NULL)
142 return;
143
144 /* Look for $PIR and then _PIR. */
145 sigaddr = bios_sigsearch(0, "$PIR", 4, 16, 0);
146 if (sigaddr == 0)
147 sigaddr = bios_sigsearch(0, "_PIR", 4, 16, 0);
148 if (sigaddr == 0)
149 return;
150
151 /* If we found something, check the checksum and length. */
152 /* XXX - Use pmap_mapdev()? */
153 pt = (struct PIR_table *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
154 if (pt->pt_header.ph_length <= sizeof(struct PIR_header))
155 return;
156 for (cv = (u_int8_t *)pt, ck = 0, i = 0;
157 i < (pt->pt_header.ph_length); i++)
158 ck += cv[i];
159 if (ck != 0)
160 return;
161
162 /* Ok, we've got a valid table. */
163 pci_route_table = pt;
164 pci_route_count = (pt->pt_header.ph_length -
165 sizeof(struct PIR_header)) /
166 sizeof(struct PIR_entry);
167}
168
169/*
170 * Find the pci_link structure for a given link ID.
171 */
172static struct pci_link *
173pci_pir_find_link(uint8_t link_id)
174{
175 struct pci_link *pci_link;
176
177 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
178 if (pci_link->pl_id == link_id)
179 return (pci_link);
180 }
181 return (NULL);
182}
183
184/*
185 * Find the link device associated with a PCI device in the table.
186 */
187static void
188pci_pir_find_link_handler(struct PIR_entry *entry, struct PIR_intpin *intpin,
189 void *arg)
190{
191 struct pci_link_lookup *lookup;
192
193 lookup = (struct pci_link_lookup *)arg;
194 if (entry->pe_bus == lookup->bus &&
195 entry->pe_device == lookup->device &&
196 intpin - entry->pe_intpin == lookup->pin)
197 *lookup->pci_link_ptr = pci_pir_find_link(intpin->link);
198}
199
200/*
201 * Check to see if a possible IRQ setting is valid.
202 */
203static int
204pci_pir_valid_irq(struct pci_link *pci_link, int irq)
205{
206
207 if (!PCI_INTERRUPT_VALID(irq))
208 return (0);
209 return (pci_link->pl_irqmask & (1 << irq));
210}
211
212/*
213 * Walk the $PIR executing the worker function for each valid intpin entry
214 * in the table. The handler is passed a pointer to both the entry and
215 * the intpin in the entry.
216 */
217static void
218pci_pir_walk_table(pir_entry_handler *handler, void *arg)
219{
220 struct PIR_entry *entry;
221 struct PIR_intpin *intpin;
222 int i, pin;
223
224 entry = &pci_route_table->pt_entry[0];
225 for (i = 0; i < pci_route_count; i++, entry++) {
226 intpin = &entry->pe_intpin[0];
227 for (pin = 0; pin < 4; pin++, intpin++)
228 if (intpin->link != 0)
229 handler(entry, intpin, arg);
230 }
231}
232
233static void
234pci_pir_create_links(struct PIR_entry *entry, struct PIR_intpin *intpin,
235 void *arg)
236{
237 struct pci_link *pci_link;
238
239 pci_link = pci_pir_find_link(intpin->link);
240 if (pci_link != NULL) {
241 pci_link->pl_references++;
242 if (intpin->irqs != pci_link->pl_irqmask) {
243 if (bootverbose)
244 printf(
245 "$PIR: Entry %d.%d.INT%c has different mask for link %#x, merging\n",
246 entry->pe_bus, entry->pe_device,
247 (intpin - entry->pe_intpin) + 'A',
248 pci_link->pl_id);
249 pci_link->pl_irqmask &= intpin->irqs;
250 }
251 } else {
252 pci_link = malloc(sizeof(struct pci_link), M_PIR, M_WAITOK);
253 pci_link->pl_id = intpin->link;
254 pci_link->pl_irqmask = intpin->irqs;
255 pci_link->pl_irq = PCI_INVALID_IRQ;
256 pci_link->pl_references = 1;
257 pci_link->pl_routed = 0;
258 TAILQ_INSERT_TAIL(&pci_links, pci_link, pl_links);
259 }
260}
261
262/*
263 * Look to see if any of the function on the PCI device at bus/device have
264 * an interrupt routed to intpin 'pin' by the BIOS.
265 */
266static uint8_t
267pci_pir_search_irq(int bus, int device, int pin)
268{
269 uint32_t value;
270 uint8_t func, maxfunc;
271
272 /* See if we have a valid device at function 0. */
273 value = pci_cfgregread(bus, device, 0, PCIR_HDRTYPE, 1);
274 if ((value & PCIM_HDRTYPE) > PCI_MAXHDRTYPE)
275 return (PCI_INVALID_IRQ);
276 if (value & PCIM_MFDEV)
277 maxfunc = PCI_FUNCMAX;
278 else
279 maxfunc = 0;
280
281 /* Scan all possible functions at this device. */
282 for (func = 0; func <= maxfunc; func++) {
283 value = pci_cfgregread(bus, device, func, PCIR_DEVVENDOR, 4);
284 if (value == 0xffffffff)
285 continue;
286 value = pci_cfgregread(bus, device, func, PCIR_INTPIN, 1);
287
288 /*
289 * See if it uses the pin in question. Note that the passed
290 * in pin uses 0 for A, .. 3 for D whereas the intpin
291 * register uses 0 for no interrupt, 1 for A, .. 4 for D.
292 */
293 if (value != pin + 1)
294 continue;
295 value = pci_cfgregread(bus, device, func, PCIR_INTLINE, 1);
296 if (bootverbose)
297 printf(
298 "$PIR: Found matching pin for %d.%d.INT%c at func %d: %d\n",
299 bus, device, pin + 'A', func, value);
300 if (value != PCI_INVALID_IRQ)
301 return (value);
302 }
303 return (PCI_INVALID_IRQ);
304}
305
306/*
307 * Try to initialize IRQ based on this device's IRQ.
308 */
309static void
310pci_pir_initial_irqs(struct PIR_entry *entry, struct PIR_intpin *intpin,
311 void *arg)
312{
313 struct pci_link *pci_link;
314 uint8_t irq, pin;
315
316 pin = intpin - entry->pe_intpin;
317 pci_link = pci_pir_find_link(intpin->link);
318 irq = pci_pir_search_irq(entry->pe_bus, entry->pe_device, pin);
319 if (irq == PCI_INVALID_IRQ || irq == pci_link->pl_irq)
320 return;
321
322 /* Don't trust any BIOS IRQs greater than 15. */
323 if (irq >= NUM_ISA_INTERRUPTS) {
324 printf(
325 "$PIR: Ignoring invalid BIOS IRQ %d from %d.%d.INT%c for link %#x\n",
326 irq, entry->pe_bus, entry->pe_device, pin + 'A',
327 pci_link->pl_id);
328 return;
329 }
330
331 /*
332 * If we don't have an IRQ for this link yet, then we trust the
333 * BIOS, even if it seems invalid from the $PIR entries.
334 */
335 if (pci_link->pl_irq == PCI_INVALID_IRQ) {
336 if (!pci_pir_valid_irq(pci_link, irq))
337 printf(
338 "$PIR: Using invalid BIOS IRQ %d from %d.%d.INT%c for link %#x\n",
339 irq, entry->pe_bus, entry->pe_device, pin + 'A',
340 pci_link->pl_id);
341 pci_link->pl_irq = irq;
342 pci_link->pl_routed = 1;
343 return;
344 }
345
346 /*
347 * We have an IRQ and it doesn't match the current IRQ for this
348 * link. If the new IRQ is invalid, then warn about it and ignore
349 * it. If the old IRQ is invalid and the new IRQ is valid, then
350 * prefer the new IRQ instead. If both IRQs are valid, then just
351 * use the first one. Note that if we ever get into this situation
352 * we are having to guess which setting the BIOS actually routed.
353 * Perhaps we should just give up instead.
354 */
355 if (!pci_pir_valid_irq(pci_link, irq)) {
356 printf(
357 "$PIR: BIOS IRQ %d for %d.%d.INT%c is not valid for link %#x\n",
358 irq, entry->pe_bus, entry->pe_device, pin + 'A',
359 pci_link->pl_id);
360 } else if (!pci_pir_valid_irq(pci_link, pci_link->pl_irq)) {
361 printf(
362"$PIR: Preferring valid BIOS IRQ %d from %d.%d.INT%c for link %#x to IRQ %d\n",
363 irq, entry->pe_bus, entry->pe_device, pin + 'A',
364 pci_link->pl_id, pci_link->pl_irq);
365 pci_link->pl_irq = irq;
366 pci_link->pl_routed = 1;
367 } else
368 printf(
369 "$PIR: BIOS IRQ %d for %d.%d.INT%c does not match link %#x irq %d\n",
370 irq, entry->pe_bus, entry->pe_device, pin + 'A',
371 pci_link->pl_id, pci_link->pl_irq);
372}
373
374/*
375 * Parse $PIR to enumerate link devices and attempt to determine their
376 * initial state. This could perhaps be cleaner if we had drivers for the
377 * various interrupt routers as they could read the initial IRQ for each
378 * link.
379 */
380static void
381pci_pir_parse(void)
382{
383 char tunable_buffer[64];
384 struct pci_link *pci_link;
385 int i, irq;
386
387 /* Only parse once. */
388 if (pir_parsed)
389 return;
390 pir_parsed = 1;
391
392 /* Enumerate link devices. */
393 TAILQ_INIT(&pci_links);
394 pci_pir_walk_table(pci_pir_create_links, NULL);
395 if (bootverbose) {
396 printf("$PIR: Links after initial probe:\n");
397 pci_pir_dump_links();
398 }
399
400 /*
401 * Check to see if the BIOS has already routed any of the links by
402 * checking each device connected to each link to see if it has a
403 * valid IRQ.
404 */
405 pci_pir_walk_table(pci_pir_initial_irqs, NULL);
406 if (bootverbose) {
407 printf("$PIR: Links after initial IRQ discovery:\n");
408 pci_pir_dump_links();
409 }
410
411 /*
412 * Allow the user to override the IRQ for a given link device. We
413 * allow invalid IRQs to be specified but warn about them. An IRQ
414 * of 255 or 0 clears any preset IRQ.
415 */
416 i = 0;
417 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
418 snprintf(tunable_buffer, sizeof(tunable_buffer),
419 "hw.pci.link.%#x.irq", pci_link->pl_id);
420 if (getenv_int(tunable_buffer, &irq) == 0)
421 continue;
422 if (irq == 0)
423 irq = PCI_INVALID_IRQ;
424 if (irq != PCI_INVALID_IRQ &&
425 !pci_pir_valid_irq(pci_link, irq) && bootverbose)
426 printf(
427 "$PIR: Warning, IRQ %d for link %#x is not listed as valid\n",
428 irq, pci_link->pl_id);
429 pci_link->pl_routed = 0;
430 pci_link->pl_irq = irq;
431 i = 1;
432 }
433 if (bootverbose && i) {
434 printf("$PIR: Links after tunable overrides:\n");
435 pci_pir_dump_links();
436 }
437
438 /*
439 * Build initial interrupt weights as well as bitmap of "known-good"
440 * IRQs that the BIOS has already used for PCI link devices.
441 */
442 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
443 if (!PCI_INTERRUPT_VALID(pci_link->pl_irq))
444 continue;
445 pir_bios_irqs |= 1 << pci_link->pl_irq;
446 pir_interrupt_weight[pci_link->pl_irq] +=
447 pci_link->pl_references;
448 }
449 if (bootverbose) {
450 printf("$PIR: IRQs used by BIOS: ");
451 pci_print_irqmask(pir_bios_irqs);
452 printf("\n");
453 printf("$PIR: Interrupt Weights:\n[ ");
454 for (i = 0; i < NUM_ISA_INTERRUPTS; i++)
455 printf(" %3d", i);
456 printf(" ]\n[ ");
457 for (i = 0; i < NUM_ISA_INTERRUPTS; i++)
458 printf(" %3d", pir_interrupt_weight[i]);
459 printf(" ]\n");
460 }
461}
462
463/*
464 * Use the PCI BIOS to route an interrupt for a given device.
465 *
466 * Input:
467 * AX = PCIBIOS_ROUTE_INTERRUPT
468 * BH = bus
469 * BL = device [7:3] / function [2:0]
470 * CH = IRQ
471 * CL = Interrupt Pin (0x0A = A, ... 0x0D = D)
472 */
473static int
474pci_pir_biosroute(int bus, int device, int func, int pin, int irq)
475{
476 struct bios_regs args;
477
478 args.eax = PCIBIOS_ROUTE_INTERRUPT;
479 args.ebx = (bus << 8) | (device << 3) | func;
480 args.ecx = (irq << 8) | (0xa + pin);
481 return (bios32(&args, PCIbios.ventry, GSEL(GCODE_SEL, SEL_KPL)));
482}
483
484
485/*
486 * Route a PCI interrupt using a link device from the $PIR.
487 */
488int
489pci_pir_route_interrupt(int bus, int device, int func, int pin)
490{
491 struct pci_link_lookup lookup;
492 struct pci_link *pci_link;
493 int error, irq;
494
495 if (pci_route_table == NULL)
496 return (PCI_INVALID_IRQ);
497
498 /* Lookup link device for this PCI device/pin. */
499 pci_link = NULL;
500 lookup.bus = bus;
501 lookup.device = device;
502 lookup.pin = pin - 1;
503 lookup.pci_link_ptr = &pci_link;
504 pci_pir_walk_table(pci_pir_find_link_handler, &lookup);
505 if (pci_link == NULL) {
506 printf("$PIR: No matching entry for %d.%d.INT%c\n", bus,
507 device, pin - 1 + 'A');
508 return (PCI_INVALID_IRQ);
509 }
510
511 /*
512 * Pick a new interrupt if we don't have one already. We look
513 * for an interrupt from several different sets. First, if
514 * this link only has one valid IRQ, use that. Second, we
515 * check the set of PCI only interrupts from the $PIR. Third,
516 * we check the set of known-good interrupts that the BIOS has
517 * already used. Lastly, we check the "all possible valid
518 * IRQs" set.
519 */
520 if (!PCI_INTERRUPT_VALID(pci_link->pl_irq)) {
521 if (pci_link->pl_irqmask != 0 && powerof2(pci_link->pl_irqmask))
522 irq = ffs(pci_link->pl_irqmask) - 1;
523 else
524 irq = pci_pir_choose_irq(pci_link,
525 pci_route_table->pt_header.ph_pci_irqs);
526 if (!PCI_INTERRUPT_VALID(irq))
527 irq = pci_pir_choose_irq(pci_link, pir_bios_irqs);
528 if (!PCI_INTERRUPT_VALID(irq))
529 irq = pci_pir_choose_irq(pci_link,
530 pci_irq_override_mask);
531 if (!PCI_INTERRUPT_VALID(irq)) {
532 if (bootverbose)
533 printf(
534 "$PIR: Failed to route interrupt for %d:%d INT%c\n",
535 bus, device, pin - 1 + 'A');
536 return (PCI_INVALID_IRQ);
537 }
538 pci_link->pl_irq = irq;
539 }
540
541 /* Ask the BIOS to route this IRQ if we haven't done so already. */
542 if (!pci_link->pl_routed) {
543 error = pci_pir_biosroute(bus, device, func, pin - 1,
544 pci_link->pl_irq);
545
546 /* Ignore errors when routing a unique interrupt. */
547 if (error && !powerof2(pci_link->pl_irqmask)) {
548 printf("$PIR: ROUTE_INTERRUPT failed.\n");
549 return (PCI_INVALID_IRQ);
550 }
551 pci_link->pl_routed = 1;
552
553 /* Ensure the interrupt is set to level/low trigger. */
554 KASSERT(pir_device != NULL, ("missing pir device"));
555 BUS_CONFIG_INTR(pir_device, pci_link->pl_irq,
556 INTR_TRIGGER_LEVEL, INTR_POLARITY_LOW);
557 }
558 if (bootverbose)
559 printf("$PIR: %d:%d INT%c routed to irq %d\n", bus, device,
560 pin - 1 + 'A', pci_link->pl_irq);
561 return (pci_link->pl_irq);
562}
563
564/*
565 * Try to pick an interrupt for the specified link from the interrupts
566 * set in the mask.
567 */
568static int
569pci_pir_choose_irq(struct pci_link *pci_link, int irqmask)
570{
571 int i, irq, realmask;
572
573 /* XXX: Need to have a #define of known bad IRQs to also mask out? */
574 realmask = pci_link->pl_irqmask & irqmask;
575 if (realmask == 0)
576 return (PCI_INVALID_IRQ);
577
578 /* Find IRQ with lowest weight. */
579 irq = PCI_INVALID_IRQ;
580 for (i = 0; i < NUM_ISA_INTERRUPTS; i++) {
581 if (!(realmask & 1 << i))
582 continue;
583 if (irq == PCI_INVALID_IRQ ||
584 pir_interrupt_weight[i] < pir_interrupt_weight[irq])
585 irq = i;
586 }
587 if (bootverbose && PCI_INTERRUPT_VALID(irq)) {
588 printf("$PIR: Found IRQ %d for link %#x from ", irq,
589 pci_link->pl_id);
590 pci_print_irqmask(realmask);
591 printf("\n");
592 }
593 return (irq);
594}
595
596static void
597pci_print_irqmask(u_int16_t irqs)
598{
599 int i, first;
600
601 if (irqs == 0) {
602 printf("none");
603 return;
604 }
605 first = 1;
606 for (i = 0; i < 16; i++, irqs >>= 1)
607 if (irqs & 1) {
608 if (!first)
609 printf(" ");
610 else
611 first = 0;
612 printf("%d", i);
613 }
614}
615
616/*
617 * Display link devices.
618 */
619static void
620pci_pir_dump_links(void)
621{
622 struct pci_link *pci_link;
623
624 printf("Link IRQ Rtd Ref IRQs\n");
625 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
626 printf("%#4x %3d %c %3d ", pci_link->pl_id,
627 pci_link->pl_irq, pci_link->pl_routed ? 'Y' : 'N',
628 pci_link->pl_references);
629 pci_print_irqmask(pci_link->pl_irqmask);
630 printf("\n");
631 }
632}
633
634/*
635 * See if any interrupts for a given PCI bus are routed in the PIR. Don't
636 * even bother looking if the BIOS doesn't support routing anyways. If we
637 * are probing a PCI-PCI bridge, then require_parse will be true and we should
638 * only succeed if a host-PCI bridge has already attached and parsed the PIR.
639 */
640int
641pci_pir_probe(int bus, int require_parse)
642{
643 int i;
644
645 if (pci_route_table == NULL || (require_parse && !pir_parsed))
646 return (0);
647 for (i = 0; i < pci_route_count; i++)
648 if (pci_route_table->pt_entry[i].pe_bus == bus)
649 return (1);
650 return (0);
651}
652
653/*
654 * The driver for the new-bus psuedo device pir0 for the $PIR table.
655 */
656
657static int
658pir_probe(device_t dev)
659{
660 char buf[64];
661
662 snprintf(buf, sizeof(buf), "PCI Interrupt Routing Table: %d Entries",
663 pci_route_count);
664 device_set_desc_copy(dev, buf);
665 return (0);
666}
667
668static int
669pir_attach(device_t dev)
670{
671
672 pci_pir_parse();
673 KASSERT(pir_device == NULL, ("Multiple pir devices"));
674 pir_device = dev;
675 return (0);
676}
677
678static void
679pir_resume_find_device(struct PIR_entry *entry, struct PIR_intpin *intpin,
680 void *arg)
681{
682 struct pci_dev_lookup *pd;
683
684 pd = (struct pci_dev_lookup *)arg;
685 if (intpin->link != pd->link || pd->bus != -1)
686 return;
687 pd->bus = entry->pe_bus;
688 pd->device = entry->pe_device;
689 pd->pin = intpin - entry->pe_intpin;
690}
691
692static int
693pir_resume(device_t dev)
694{
695 struct pci_dev_lookup pd;
696 struct pci_link *pci_link;
697 int error;
698
699 /* Ask the BIOS to re-route each link that was already routed. */
700 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
701 if (!PCI_INTERRUPT_VALID(pci_link->pl_irq)) {
702 KASSERT(!pci_link->pl_routed,
703 ("link %#x is routed but has invalid PCI IRQ",
704 pci_link->pl_id));
705 continue;
706 }
707 if (pci_link->pl_routed) {
708 pd.bus = -1;
709 pd.link = pci_link->pl_id;
710 pci_pir_walk_table(pir_resume_find_device, &pd);
711 KASSERT(pd.bus != -1,
712 ("did not find matching entry for link %#x in the $PIR table",
713 pci_link->pl_id));
714 if (bootverbose)
715 device_printf(dev,
716 "Using %d.%d.INT%c to route link %#x to IRQ %d\n",
717 pd.bus, pd.device, pd.pin + 'A',
718 pci_link->pl_id, pci_link->pl_irq);
719 error = pci_pir_biosroute(pd.bus, pd.device, 0, pd.pin,
720 pci_link->pl_irq);
721 if (error)
722 device_printf(dev,
723 "ROUTE_INTERRUPT on resume for link %#x failed.\n",
724 pci_link->pl_id);
725 }
726 }
727 return (0);
728}
729
730static device_method_t pir_methods[] = {
731 /* Device interface */
732 DEVMETHOD(device_probe, pir_probe),
733 DEVMETHOD(device_attach, pir_attach),
734 DEVMETHOD(device_resume, pir_resume),
735
736 { 0, 0 }
737};
738
739static driver_t pir_driver = {
740 "pir",
741 pir_methods,
742 1,
743};
744
745static devclass_t pir_devclass;
746
747DRIVER_MODULE(pir, legacy, pir_driver, pir_devclass, 0, 0);