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>
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice unmodified, this list of conditions, and the following
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.
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.
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
33 #include <sys/param.h>
34 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/module.h>
39 #include <sys/sysctl.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>
50 #define NUM_ISA_INTERRUPTS 16
53 * A link device. Loosely based on the ACPI PCI link device. This doesn't
54 * try to support priorities for different ISA interrupts.
57 TAILQ_ENTRY(pci_link) pl_links;
65 struct pci_link_lookup {
66 struct pci_link **pci_link_ptr;
72 struct pci_dev_lookup {
79 typedef void pir_entry_handler(struct PIR_entry *entry,
80 struct PIR_intpin* intpin, void *arg);
82 static void pci_print_irqmask(u_int16_t irqs);
83 static int pci_pir_biosroute(int bus, int device, int func, int pin,
85 static int pci_pir_choose_irq(struct pci_link *pci_link, int irqmask);
86 static void pci_pir_create_links(struct PIR_entry *entry,
87 struct PIR_intpin *intpin, void *arg);
88 static void pci_pir_dump_links(void);
89 static struct pci_link *pci_pir_find_link(uint8_t link_id);
90 static void pci_pir_find_link_handler(struct PIR_entry *entry,
91 struct PIR_intpin *intpin, void *arg);
92 static void pci_pir_initial_irqs(struct PIR_entry *entry,
93 struct PIR_intpin *intpin, void *arg);
94 static void pci_pir_parse(void);
95 static uint8_t pci_pir_search_irq(int bus, int device, int pin);
96 static int pci_pir_valid_irq(struct pci_link *pci_link, int irq);
97 static void pci_pir_walk_table(pir_entry_handler *handler, void *arg);
99 static MALLOC_DEFINE(M_PIR, "$PIR", "$PIR structures");
101 static struct PIR_table *pci_route_table;
102 static device_t pir_device;
103 static int pci_route_count, pir_bios_irqs, pir_parsed;
104 static TAILQ_HEAD(, pci_link) pci_links;
105 static int pir_interrupt_weight[NUM_ISA_INTERRUPTS];
108 SYSCTL_DECL(_hw_pci);
110 /* XXX this likely should live in a header file */
111 /* IRQs 3, 4, 5, 6, 7, 9, 10, 11, 12, 14, 15 */
112 #define PCI_IRQ_OVERRIDE_MASK 0xdef8
114 static uint32_t pci_irq_override_mask = PCI_IRQ_OVERRIDE_MASK;
115 SYSCTL_INT(_hw_pci, OID_AUTO, irq_override_mask, CTLFLAG_RDTUN,
116 &pci_irq_override_mask, PCI_IRQ_OVERRIDE_MASK,
117 "Mask of allowed irqs to try to route when it has no good clue about\n"
118 "which irqs it should use.");
121 * Look for the interrupt routing table.
123 * We use PCI BIOS's PIR table if it's available. $PIR is the standard way
124 * to do this. Sadly, some machines are not standards conforming and have
125 * _PIR instead. We shrug and cope by looking for both.
130 struct PIR_table *pt;
135 /* Don't try if we've already found a table. */
136 if (pci_route_table != NULL)
139 /* Look for $PIR and then _PIR. */
140 sigaddr = bios_sigsearch(0, "$PIR", 4, 16, 0);
142 sigaddr = bios_sigsearch(0, "_PIR", 4, 16, 0);
146 /* If we found something, check the checksum and length. */
147 /* XXX - Use pmap_mapdev()? */
148 pt = (struct PIR_table *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
149 if (pt->pt_header.ph_length <= sizeof(struct PIR_header))
151 for (cv = (u_int8_t *)pt, ck = 0, i = 0;
152 i < (pt->pt_header.ph_length); i++)
157 /* Ok, we've got a valid table. */
158 pci_route_table = pt;
159 pci_route_count = (pt->pt_header.ph_length -
160 sizeof(struct PIR_header)) /
161 sizeof(struct PIR_entry);
165 * Find the pci_link structure for a given link ID.
167 static struct pci_link *
168 pci_pir_find_link(uint8_t link_id)
170 struct pci_link *pci_link;
172 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
173 if (pci_link->pl_id == link_id)
180 * Find the link device associated with a PCI device in the table.
183 pci_pir_find_link_handler(struct PIR_entry *entry, struct PIR_intpin *intpin,
186 struct pci_link_lookup *lookup;
188 lookup = (struct pci_link_lookup *)arg;
189 if (entry->pe_bus == lookup->bus &&
190 entry->pe_device == lookup->device &&
191 intpin - entry->pe_intpin == lookup->pin)
192 *lookup->pci_link_ptr = pci_pir_find_link(intpin->link);
196 * Check to see if a possible IRQ setting is valid.
199 pci_pir_valid_irq(struct pci_link *pci_link, int irq)
202 if (!PCI_INTERRUPT_VALID(irq))
204 return (pci_link->pl_irqmask & (1 << irq));
208 * Walk the $PIR executing the worker function for each valid intpin entry
209 * in the table. The handler is passed a pointer to both the entry and
210 * the intpin in the entry.
213 pci_pir_walk_table(pir_entry_handler *handler, void *arg)
215 struct PIR_entry *entry;
216 struct PIR_intpin *intpin;
219 entry = &pci_route_table->pt_entry[0];
220 for (i = 0; i < pci_route_count; i++, entry++) {
221 intpin = &entry->pe_intpin[0];
222 for (pin = 0; pin < 4; pin++, intpin++)
223 if (intpin->link != 0)
224 handler(entry, intpin, arg);
229 pci_pir_create_links(struct PIR_entry *entry, struct PIR_intpin *intpin,
232 struct pci_link *pci_link;
234 pci_link = pci_pir_find_link(intpin->link);
235 if (pci_link != NULL) {
236 pci_link->pl_references++;
237 if (intpin->irqs != pci_link->pl_irqmask) {
240 "$PIR: Entry %d.%d.INT%c has different mask for link %#x, merging\n",
241 entry->pe_bus, entry->pe_device,
242 (intpin - entry->pe_intpin) + 'A',
244 pci_link->pl_irqmask &= intpin->irqs;
247 pci_link = malloc(sizeof(struct pci_link), M_PIR, M_WAITOK);
248 pci_link->pl_id = intpin->link;
249 pci_link->pl_irqmask = intpin->irqs;
250 pci_link->pl_irq = PCI_INVALID_IRQ;
251 pci_link->pl_references = 1;
252 pci_link->pl_routed = 0;
253 TAILQ_INSERT_TAIL(&pci_links, pci_link, pl_links);
258 * Look to see if any of the function on the PCI device at bus/device have
259 * an interrupt routed to intpin 'pin' by the BIOS.
262 pci_pir_search_irq(int bus, int device, int pin)
265 uint8_t func, maxfunc;
267 /* See if we have a valid device at function 0. */
268 value = pci_cfgregread(bus, device, 0, PCIR_HDRTYPE, 1);
269 if ((value & PCIM_HDRTYPE) > PCI_MAXHDRTYPE)
270 return (PCI_INVALID_IRQ);
271 if (value & PCIM_MFDEV)
272 maxfunc = PCI_FUNCMAX;
276 /* Scan all possible functions at this device. */
277 for (func = 0; func <= maxfunc; func++) {
278 value = pci_cfgregread(bus, device, func, PCIR_DEVVENDOR, 4);
279 if (value == 0xffffffff)
281 value = pci_cfgregread(bus, device, func, PCIR_INTPIN, 1);
284 * See if it uses the pin in question. Note that the passed
285 * in pin uses 0 for A, .. 3 for D whereas the intpin
286 * register uses 0 for no interrupt, 1 for A, .. 4 for D.
288 if (value != pin + 1)
290 value = pci_cfgregread(bus, device, func, PCIR_INTLINE, 1);
293 "$PIR: Found matching pin for %d.%d.INT%c at func %d: %d\n",
294 bus, device, pin + 'A', func, value);
295 if (value != PCI_INVALID_IRQ)
298 return (PCI_INVALID_IRQ);
302 * Try to initialize IRQ based on this device's IRQ.
305 pci_pir_initial_irqs(struct PIR_entry *entry, struct PIR_intpin *intpin,
308 struct pci_link *pci_link;
311 pin = intpin - entry->pe_intpin;
312 pci_link = pci_pir_find_link(intpin->link);
313 irq = pci_pir_search_irq(entry->pe_bus, entry->pe_device, pin);
314 if (irq == PCI_INVALID_IRQ || irq == pci_link->pl_irq)
317 /* Don't trust any BIOS IRQs greater than 15. */
318 if (irq >= NUM_ISA_INTERRUPTS) {
320 "$PIR: Ignoring invalid BIOS IRQ %d from %d.%d.INT%c for link %#x\n",
321 irq, entry->pe_bus, entry->pe_device, pin + 'A',
327 * If we don't have an IRQ for this link yet, then we trust the
328 * BIOS, even if it seems invalid from the $PIR entries.
330 if (pci_link->pl_irq == PCI_INVALID_IRQ) {
331 if (!pci_pir_valid_irq(pci_link, irq))
333 "$PIR: Using invalid BIOS IRQ %d from %d.%d.INT%c for link %#x\n",
334 irq, entry->pe_bus, entry->pe_device, pin + 'A',
336 pci_link->pl_irq = irq;
337 pci_link->pl_routed = 1;
342 * We have an IRQ and it doesn't match the current IRQ for this
343 * link. If the new IRQ is invalid, then warn about it and ignore
344 * it. If the old IRQ is invalid and the new IRQ is valid, then
345 * prefer the new IRQ instead. If both IRQs are valid, then just
346 * use the first one. Note that if we ever get into this situation
347 * we are having to guess which setting the BIOS actually routed.
348 * Perhaps we should just give up instead.
350 if (!pci_pir_valid_irq(pci_link, irq)) {
352 "$PIR: BIOS IRQ %d for %d.%d.INT%c is not valid for link %#x\n",
353 irq, entry->pe_bus, entry->pe_device, pin + 'A',
355 } else if (!pci_pir_valid_irq(pci_link, pci_link->pl_irq)) {
357 "$PIR: Preferring valid BIOS IRQ %d from %d.%d.INT%c for link %#x to IRQ %d\n",
358 irq, entry->pe_bus, entry->pe_device, pin + 'A',
359 pci_link->pl_id, pci_link->pl_irq);
360 pci_link->pl_irq = irq;
361 pci_link->pl_routed = 1;
364 "$PIR: BIOS IRQ %d for %d.%d.INT%c does not match link %#x irq %d\n",
365 irq, entry->pe_bus, entry->pe_device, pin + 'A',
366 pci_link->pl_id, pci_link->pl_irq);
370 * Parse $PIR to enumerate link devices and attempt to determine their
371 * initial state. This could perhaps be cleaner if we had drivers for the
372 * various interrupt routers as they could read the initial IRQ for each
378 char tunable_buffer[64];
379 struct pci_link *pci_link;
382 /* Only parse once. */
387 /* Enumerate link devices. */
388 TAILQ_INIT(&pci_links);
389 pci_pir_walk_table(pci_pir_create_links, NULL);
391 printf("$PIR: Links after initial probe:\n");
392 pci_pir_dump_links();
396 * Check to see if the BIOS has already routed any of the links by
397 * checking each device connected to each link to see if it has a
400 pci_pir_walk_table(pci_pir_initial_irqs, NULL);
402 printf("$PIR: Links after initial IRQ discovery:\n");
403 pci_pir_dump_links();
407 * Allow the user to override the IRQ for a given link device. We
408 * allow invalid IRQs to be specified but warn about them. An IRQ
409 * of 255 or 0 clears any preset IRQ.
412 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
413 snprintf(tunable_buffer, sizeof(tunable_buffer),
414 "hw.pci.link.%#x.irq", pci_link->pl_id);
415 if (getenv_int(tunable_buffer, &irq) == 0)
418 irq = PCI_INVALID_IRQ;
419 if (irq != PCI_INVALID_IRQ &&
420 !pci_pir_valid_irq(pci_link, irq) && bootverbose)
422 "$PIR: Warning, IRQ %d for link %#x is not listed as valid\n",
423 irq, pci_link->pl_id);
424 pci_link->pl_routed = 0;
425 pci_link->pl_irq = irq;
428 if (bootverbose && i) {
429 printf("$PIR: Links after tunable overrides:\n");
430 pci_pir_dump_links();
434 * Build initial interrupt weights as well as bitmap of "known-good"
435 * IRQs that the BIOS has already used for PCI link devices.
437 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
438 if (!PCI_INTERRUPT_VALID(pci_link->pl_irq))
440 pir_bios_irqs |= 1 << pci_link->pl_irq;
441 pir_interrupt_weight[pci_link->pl_irq] +=
442 pci_link->pl_references;
445 printf("$PIR: IRQs used by BIOS: ");
446 pci_print_irqmask(pir_bios_irqs);
448 printf("$PIR: Interrupt Weights:\n[ ");
449 for (i = 0; i < NUM_ISA_INTERRUPTS; i++)
452 for (i = 0; i < NUM_ISA_INTERRUPTS; i++)
453 printf(" %3d", pir_interrupt_weight[i]);
459 * Use the PCI BIOS to route an interrupt for a given device.
462 * AX = PCIBIOS_ROUTE_INTERRUPT
464 * BL = device [7:3] / function [2:0]
466 * CL = Interrupt Pin (0x0A = A, ... 0x0D = D)
469 pci_pir_biosroute(int bus, int device, int func, int pin, int irq)
471 struct bios_regs args;
473 args.eax = PCIBIOS_ROUTE_INTERRUPT;
474 args.ebx = (bus << 8) | (device << 3) | func;
475 args.ecx = (irq << 8) | (0xa + pin);
476 return (bios32(&args, PCIbios.ventry, GSEL(GCODE_SEL, SEL_KPL)));
481 * Route a PCI interrupt using a link device from the $PIR.
484 pci_pir_route_interrupt(int bus, int device, int func, int pin)
486 struct pci_link_lookup lookup;
487 struct pci_link *pci_link;
490 if (pci_route_table == NULL)
491 return (PCI_INVALID_IRQ);
493 /* Lookup link device for this PCI device/pin. */
496 lookup.device = device;
497 lookup.pin = pin - 1;
498 lookup.pci_link_ptr = &pci_link;
499 pci_pir_walk_table(pci_pir_find_link_handler, &lookup);
500 if (pci_link == NULL) {
501 printf("$PIR: No matching entry for %d.%d.INT%c\n", bus,
502 device, pin - 1 + 'A');
503 return (PCI_INVALID_IRQ);
507 * Pick a new interrupt if we don't have one already. We look
508 * for an interrupt from several different sets. First, if
509 * this link only has one valid IRQ, use that. Second, we
510 * check the set of PCI only interrupts from the $PIR. Third,
511 * we check the set of known-good interrupts that the BIOS has
512 * already used. Lastly, we check the "all possible valid
515 if (!PCI_INTERRUPT_VALID(pci_link->pl_irq)) {
516 if (pci_link->pl_irqmask != 0 && powerof2(pci_link->pl_irqmask))
517 irq = ffs(pci_link->pl_irqmask) - 1;
519 irq = pci_pir_choose_irq(pci_link,
520 pci_route_table->pt_header.ph_pci_irqs);
521 if (!PCI_INTERRUPT_VALID(irq))
522 irq = pci_pir_choose_irq(pci_link, pir_bios_irqs);
523 if (!PCI_INTERRUPT_VALID(irq))
524 irq = pci_pir_choose_irq(pci_link,
525 pci_irq_override_mask);
526 if (!PCI_INTERRUPT_VALID(irq)) {
529 "$PIR: Failed to route interrupt for %d:%d INT%c\n",
530 bus, device, pin - 1 + 'A');
531 return (PCI_INVALID_IRQ);
533 pci_link->pl_irq = irq;
536 /* Ask the BIOS to route this IRQ if we haven't done so already. */
537 if (!pci_link->pl_routed) {
538 error = pci_pir_biosroute(bus, device, func, pin - 1,
541 /* Ignore errors when routing a unique interrupt. */
542 if (error && !powerof2(pci_link->pl_irqmask)) {
543 printf("$PIR: ROUTE_INTERRUPT failed.\n");
544 return (PCI_INVALID_IRQ);
546 pci_link->pl_routed = 1;
548 /* Ensure the interrupt is set to level/low trigger. */
549 KASSERT(pir_device != NULL, ("missing pir device"));
550 BUS_CONFIG_INTR(pir_device, pci_link->pl_irq,
551 INTR_TRIGGER_LEVEL, INTR_POLARITY_LOW);
554 printf("$PIR: %d:%d INT%c routed to irq %d\n", bus, device,
555 pin - 1 + 'A', pci_link->pl_irq);
556 return (pci_link->pl_irq);
560 * Try to pick an interrupt for the specified link from the interrupts
564 pci_pir_choose_irq(struct pci_link *pci_link, int irqmask)
566 int i, irq, realmask;
568 /* XXX: Need to have a #define of known bad IRQs to also mask out? */
569 realmask = pci_link->pl_irqmask & irqmask;
571 return (PCI_INVALID_IRQ);
573 /* Find IRQ with lowest weight. */
574 irq = PCI_INVALID_IRQ;
575 for (i = 0; i < NUM_ISA_INTERRUPTS; i++) {
576 if (!(realmask & 1 << i))
578 if (irq == PCI_INVALID_IRQ ||
579 pir_interrupt_weight[i] < pir_interrupt_weight[irq])
582 if (bootverbose && PCI_INTERRUPT_VALID(irq)) {
583 printf("$PIR: Found IRQ %d for link %#x from ", irq,
585 pci_print_irqmask(realmask);
592 pci_print_irqmask(u_int16_t irqs)
601 for (i = 0; i < 16; i++, irqs >>= 1)
612 * Display link devices.
615 pci_pir_dump_links(void)
617 struct pci_link *pci_link;
619 printf("Link IRQ Rtd Ref IRQs\n");
620 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
621 printf("%#4x %3d %c %3d ", pci_link->pl_id,
622 pci_link->pl_irq, pci_link->pl_routed ? 'Y' : 'N',
623 pci_link->pl_references);
624 pci_print_irqmask(pci_link->pl_irqmask);
630 * See if any interrupts for a given PCI bus are routed in the PIR. Don't
631 * even bother looking if the BIOS doesn't support routing anyways. If we
632 * are probing a PCI-PCI bridge, then require_parse will be true and we should
633 * only succeed if a host-PCI bridge has already attached and parsed the PIR.
636 pci_pir_probe(int bus, int require_parse)
640 if (pci_route_table == NULL || (require_parse && !pir_parsed))
642 for (i = 0; i < pci_route_count; i++)
643 if (pci_route_table->pt_entry[i].pe_bus == bus)
649 * The driver for the new-bus psuedo device pir0 for the $PIR table.
653 pir_probe(device_t dev)
657 snprintf(buf, sizeof(buf), "PCI Interrupt Routing Table: %d Entries",
659 device_set_desc_copy(dev, buf);
664 pir_attach(device_t dev)
668 KASSERT(pir_device == NULL, ("Multiple pir devices"));
674 pir_resume_find_device(struct PIR_entry *entry, struct PIR_intpin *intpin,
677 struct pci_dev_lookup *pd;
679 pd = (struct pci_dev_lookup *)arg;
680 if (intpin->link != pd->link || pd->bus != -1)
682 pd->bus = entry->pe_bus;
683 pd->device = entry->pe_device;
684 pd->pin = intpin - entry->pe_intpin;
688 pir_resume(device_t dev)
690 struct pci_dev_lookup pd;
691 struct pci_link *pci_link;
694 /* Ask the BIOS to re-route each link that was already routed. */
695 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
696 if (!PCI_INTERRUPT_VALID(pci_link->pl_irq)) {
697 KASSERT(!pci_link->pl_routed,
698 ("link %#x is routed but has invalid PCI IRQ",
702 if (pci_link->pl_routed) {
704 pd.link = pci_link->pl_id;
705 pci_pir_walk_table(pir_resume_find_device, &pd);
706 KASSERT(pd.bus != -1,
707 ("did not find matching entry for link %#x in the $PIR table",
711 "Using %d.%d.INT%c to route link %#x to IRQ %d\n",
712 pd.bus, pd.device, pd.pin + 'A',
713 pci_link->pl_id, pci_link->pl_irq);
714 error = pci_pir_biosroute(pd.bus, pd.device, 0, pd.pin,
718 "ROUTE_INTERRUPT on resume for link %#x failed.\n",
725 static device_method_t pir_methods[] = {
726 /* Device interface */
727 DEVMETHOD(device_probe, pir_probe),
728 DEVMETHOD(device_attach, pir_attach),
729 DEVMETHOD(device_resume, pir_resume),
734 static driver_t pir_driver = {
740 static devclass_t pir_devclass;
742 DRIVER_MODULE(pir, legacy, pir_driver, pir_devclass, 0, 0);