2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1997, Stefan Esser <se@freebsd.org>
5 * Copyright (c) 2000, Michael Smith <msmith@freebsd.org>
6 * Copyright (c) 2000, BSDi
8 * Copyright (c) 2004, John Baldwin <jhb@FreeBSD.org>
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice unmodified, this list of conditions, and the following
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
35 #include <sys/param.h>
36 #include <sys/systm.h>
38 #include <sys/kernel.h>
39 #include <sys/malloc.h>
40 #include <sys/module.h>
41 #include <sys/sysctl.h>
44 #include <vm/vm_param.h>
45 #include <machine/md_var.h>
46 #include <dev/pci/pcivar.h>
47 #include <dev/pci/pcireg.h>
48 #include <machine/pci_cfgreg.h>
49 #include <machine/segments.h>
50 #include <machine/pc/bios.h>
52 #define NUM_ISA_INTERRUPTS 16
55 * A link device. Loosely based on the ACPI PCI link device. This doesn't
56 * try to support priorities for different ISA interrupts.
59 TAILQ_ENTRY(pci_link) pl_links;
67 struct pci_link_lookup {
68 struct pci_link **pci_link_ptr;
74 struct pci_dev_lookup {
81 typedef void pir_entry_handler(struct PIR_entry *entry,
82 struct PIR_intpin* intpin, void *arg);
84 static void pci_print_irqmask(u_int16_t irqs);
85 static int pci_pir_biosroute(int bus, int device, int func, int pin,
87 static int pci_pir_choose_irq(struct pci_link *pci_link, int irqmask);
88 static void pci_pir_create_links(struct PIR_entry *entry,
89 struct PIR_intpin *intpin, void *arg);
90 static void pci_pir_dump_links(void);
91 static struct pci_link *pci_pir_find_link(uint8_t link_id);
92 static void pci_pir_find_link_handler(struct PIR_entry *entry,
93 struct PIR_intpin *intpin, void *arg);
94 static void pci_pir_initial_irqs(struct PIR_entry *entry,
95 struct PIR_intpin *intpin, void *arg);
96 static void pci_pir_parse(void);
97 static uint8_t pci_pir_search_irq(int bus, int device, int pin);
98 static int pci_pir_valid_irq(struct pci_link *pci_link, int irq);
99 static void pci_pir_walk_table(pir_entry_handler *handler, void *arg);
101 static MALLOC_DEFINE(M_PIR, "$PIR", "$PIR structures");
103 static struct PIR_table *pci_route_table;
104 static device_t pir_device;
105 static int pci_route_count, pir_bios_irqs, pir_parsed;
106 static TAILQ_HEAD(, pci_link) pci_links;
107 static int pir_interrupt_weight[NUM_ISA_INTERRUPTS];
110 SYSCTL_DECL(_hw_pci);
112 /* XXX this likely should live in a header file */
113 /* IRQs 3, 4, 5, 6, 7, 9, 10, 11, 12, 14, 15 */
114 #define PCI_IRQ_OVERRIDE_MASK 0xdef8
116 static uint32_t pci_irq_override_mask = PCI_IRQ_OVERRIDE_MASK;
117 SYSCTL_INT(_hw_pci, OID_AUTO, irq_override_mask, CTLFLAG_RDTUN,
118 &pci_irq_override_mask, PCI_IRQ_OVERRIDE_MASK,
119 "Mask of allowed irqs to try to route when it has no good clue about\n"
120 "which irqs it should use.");
123 * Look for the interrupt routing table.
125 * We use PCI BIOS's PIR table if it's available. $PIR is the standard way
126 * to do this. Sadly, some machines are not standards conforming and have
127 * _PIR instead. We shrug and cope by looking for both.
132 struct PIR_table *pt;
137 /* Don't try if we've already found a table. */
138 if (pci_route_table != NULL)
141 /* Look for $PIR and then _PIR. */
142 sigaddr = bios_sigsearch(0, "$PIR", 4, 16, 0);
144 sigaddr = bios_sigsearch(0, "_PIR", 4, 16, 0);
148 /* If we found something, check the checksum and length. */
149 /* XXX - Use pmap_mapdev()? */
150 pt = (struct PIR_table *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
151 if (pt->pt_header.ph_length <= sizeof(struct PIR_header))
153 for (cv = (u_int8_t *)pt, ck = 0, i = 0;
154 i < (pt->pt_header.ph_length); i++)
159 /* Ok, we've got a valid table. */
160 pci_route_table = pt;
161 pci_route_count = (pt->pt_header.ph_length -
162 sizeof(struct PIR_header)) /
163 sizeof(struct PIR_entry);
167 * Find the pci_link structure for a given link ID.
169 static struct pci_link *
170 pci_pir_find_link(uint8_t link_id)
172 struct pci_link *pci_link;
174 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
175 if (pci_link->pl_id == link_id)
182 * Find the link device associated with a PCI device in the table.
185 pci_pir_find_link_handler(struct PIR_entry *entry, struct PIR_intpin *intpin,
188 struct pci_link_lookup *lookup;
190 lookup = (struct pci_link_lookup *)arg;
191 if (entry->pe_bus == lookup->bus &&
192 entry->pe_device == lookup->device &&
193 intpin - entry->pe_intpin == lookup->pin)
194 *lookup->pci_link_ptr = pci_pir_find_link(intpin->link);
198 * Check to see if a possible IRQ setting is valid.
201 pci_pir_valid_irq(struct pci_link *pci_link, int irq)
204 if (!PCI_INTERRUPT_VALID(irq))
206 return (pci_link->pl_irqmask & (1 << irq));
210 * Walk the $PIR executing the worker function for each valid intpin entry
211 * in the table. The handler is passed a pointer to both the entry and
212 * the intpin in the entry.
215 pci_pir_walk_table(pir_entry_handler *handler, void *arg)
217 struct PIR_entry *entry;
218 struct PIR_intpin *intpin;
221 entry = &pci_route_table->pt_entry[0];
222 for (i = 0; i < pci_route_count; i++, entry++) {
223 intpin = &entry->pe_intpin[0];
224 for (pin = 0; pin < 4; pin++, intpin++)
225 if (intpin->link != 0)
226 handler(entry, intpin, arg);
231 pci_pir_create_links(struct PIR_entry *entry, struct PIR_intpin *intpin,
234 struct pci_link *pci_link;
236 pci_link = pci_pir_find_link(intpin->link);
237 if (pci_link != NULL) {
238 pci_link->pl_references++;
239 if (intpin->irqs != pci_link->pl_irqmask) {
242 "$PIR: Entry %d.%d.INT%c has different mask for link %#x, merging\n",
243 entry->pe_bus, entry->pe_device,
244 (intpin - entry->pe_intpin) + 'A',
246 pci_link->pl_irqmask &= intpin->irqs;
249 pci_link = malloc(sizeof(struct pci_link), M_PIR, M_WAITOK);
250 pci_link->pl_id = intpin->link;
251 pci_link->pl_irqmask = intpin->irqs;
252 pci_link->pl_irq = PCI_INVALID_IRQ;
253 pci_link->pl_references = 1;
254 pci_link->pl_routed = 0;
255 TAILQ_INSERT_TAIL(&pci_links, pci_link, pl_links);
260 * Look to see if any of the functions on the PCI device at bus/device
261 * have an interrupt routed to intpin 'pin' by the BIOS.
264 pci_pir_search_irq(int bus, int device, int pin)
267 uint8_t func, maxfunc;
269 /* See if we have a valid device at function 0. */
270 value = pci_cfgregread(bus, device, 0, PCIR_VENDOR, 2);
271 if (value == PCIV_INVALID)
272 return (PCI_INVALID_IRQ);
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;
281 /* Scan all possible functions at this device. */
282 for (func = 0; func <= maxfunc; func++) {
283 value = pci_cfgregread(bus, device, func, PCIR_VENDOR, 2);
284 if (value == PCIV_INVALID)
286 value = pci_cfgregread(bus, device, func, PCIR_INTPIN, 1);
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.
293 if (value != pin + 1)
295 value = pci_cfgregread(bus, device, func, PCIR_INTLINE, 1);
298 "$PIR: Found matching pin for %d.%d.INT%c at func %d: %d\n",
299 bus, device, pin + 'A', func, value);
300 if (value != PCI_INVALID_IRQ)
303 return (PCI_INVALID_IRQ);
307 * Try to initialize IRQ based on this device's IRQ.
310 pci_pir_initial_irqs(struct PIR_entry *entry, struct PIR_intpin *intpin,
313 struct pci_link *pci_link;
316 pin = intpin - entry->pe_intpin;
317 pci_link = pci_pir_find_link(intpin->link);
318 irq = pci_pir_search_irq(entry->pe_bus, entry->pe_device, pin);
319 if (irq == PCI_INVALID_IRQ || irq == pci_link->pl_irq)
322 /* Don't trust any BIOS IRQs greater than 15. */
323 if (irq >= NUM_ISA_INTERRUPTS) {
325 "$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',
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 $PIR entries.
335 if (pci_link->pl_irq == PCI_INVALID_IRQ) {
336 if (!pci_pir_valid_irq(pci_link, irq))
338 "$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',
341 pci_link->pl_irq = irq;
342 pci_link->pl_routed = 1;
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.
355 if (!pci_pir_valid_irq(pci_link, irq)) {
357 "$PIR: BIOS IRQ %d for %d.%d.INT%c is not valid for link %#x\n",
358 irq, entry->pe_bus, entry->pe_device, pin + 'A',
360 } else if (!pci_pir_valid_irq(pci_link, pci_link->pl_irq)) {
362 "$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;
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);
375 * Parse $PIR to enumerate link devices and attempt to determine their
376 * initial state. This could perhaps be cleaner if we had drivers for the
377 * various interrupt routers as they could read the initial IRQ for each
383 char tunable_buffer[64];
384 struct pci_link *pci_link;
387 /* Only parse once. */
392 /* Enumerate link devices. */
393 TAILQ_INIT(&pci_links);
394 pci_pir_walk_table(pci_pir_create_links, NULL);
396 printf("$PIR: Links after initial probe:\n");
397 pci_pir_dump_links();
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
405 pci_pir_walk_table(pci_pir_initial_irqs, NULL);
407 printf("$PIR: Links after initial IRQ discovery:\n");
408 pci_pir_dump_links();
412 * Allow the user to override the IRQ for a given link device. We
413 * allow invalid IRQs to be specified but warn about them. An IRQ
414 * of 255 or 0 clears any preset IRQ.
417 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
418 snprintf(tunable_buffer, sizeof(tunable_buffer),
419 "hw.pci.link.%#x.irq", pci_link->pl_id);
420 if (getenv_int(tunable_buffer, &irq) == 0)
423 irq = PCI_INVALID_IRQ;
424 if (irq != PCI_INVALID_IRQ &&
425 !pci_pir_valid_irq(pci_link, irq) && bootverbose)
427 "$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;
433 if (bootverbose && i) {
434 printf("$PIR: Links after tunable overrides:\n");
435 pci_pir_dump_links();
439 * Build initial interrupt weights as well as bitmap of "known-good"
440 * IRQs that the BIOS has already used for PCI link devices.
442 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
443 if (!PCI_INTERRUPT_VALID(pci_link->pl_irq))
445 pir_bios_irqs |= 1 << pci_link->pl_irq;
446 pir_interrupt_weight[pci_link->pl_irq] +=
447 pci_link->pl_references;
450 printf("$PIR: IRQs used by BIOS: ");
451 pci_print_irqmask(pir_bios_irqs);
453 printf("$PIR: Interrupt Weights:\n[ ");
454 for (i = 0; i < NUM_ISA_INTERRUPTS; i++)
457 for (i = 0; i < NUM_ISA_INTERRUPTS; i++)
458 printf(" %3d", pir_interrupt_weight[i]);
464 * Use the PCI BIOS to route an interrupt for a given device.
467 * AX = PCIBIOS_ROUTE_INTERRUPT
469 * BL = device [7:3] / function [2:0]
471 * CL = Interrupt Pin (0x0A = A, ... 0x0D = D)
474 pci_pir_biosroute(int bus, int device, int func, int pin, int irq)
476 struct bios_regs args;
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)));
485 * Route a PCI interrupt using a link device from the $PIR.
488 pci_pir_route_interrupt(int bus, int device, int func, int pin)
490 struct pci_link_lookup lookup;
491 struct pci_link *pci_link;
494 if (pci_route_table == NULL)
495 return (PCI_INVALID_IRQ);
497 /* Lookup link device for this PCI device/pin. */
500 lookup.device = device;
501 lookup.pin = pin - 1;
502 lookup.pci_link_ptr = &pci_link;
503 pci_pir_walk_table(pci_pir_find_link_handler, &lookup);
504 if (pci_link == NULL) {
505 printf("$PIR: No matching entry for %d.%d.INT%c\n", bus,
506 device, pin - 1 + 'A');
507 return (PCI_INVALID_IRQ);
511 * Pick a new interrupt if we don't have one already. We look
512 * for an interrupt from several different sets. First, if
513 * this link only has one valid IRQ, use that. Second, we
514 * check the set of PCI only interrupts from the $PIR. Third,
515 * we check the set of known-good interrupts that the BIOS has
516 * already used. Lastly, we check the "all possible valid
519 if (!PCI_INTERRUPT_VALID(pci_link->pl_irq)) {
520 if (pci_link->pl_irqmask != 0 && powerof2(pci_link->pl_irqmask))
521 irq = ffs(pci_link->pl_irqmask) - 1;
523 irq = pci_pir_choose_irq(pci_link,
524 pci_route_table->pt_header.ph_pci_irqs);
525 if (!PCI_INTERRUPT_VALID(irq))
526 irq = pci_pir_choose_irq(pci_link, pir_bios_irqs);
527 if (!PCI_INTERRUPT_VALID(irq))
528 irq = pci_pir_choose_irq(pci_link,
529 pci_irq_override_mask);
530 if (!PCI_INTERRUPT_VALID(irq)) {
533 "$PIR: Failed to route interrupt for %d:%d INT%c\n",
534 bus, device, pin - 1 + 'A');
535 return (PCI_INVALID_IRQ);
537 pci_link->pl_irq = irq;
540 /* Ask the BIOS to route this IRQ if we haven't done so already. */
541 if (!pci_link->pl_routed) {
542 error = pci_pir_biosroute(bus, device, func, pin - 1,
545 /* Ignore errors when routing a unique interrupt. */
546 if (error && !powerof2(pci_link->pl_irqmask)) {
547 printf("$PIR: ROUTE_INTERRUPT failed.\n");
548 return (PCI_INVALID_IRQ);
550 pci_link->pl_routed = 1;
552 /* Ensure the interrupt is set to level/low trigger. */
553 KASSERT(pir_device != NULL, ("missing pir device"));
554 BUS_CONFIG_INTR(pir_device, pci_link->pl_irq,
555 INTR_TRIGGER_LEVEL, INTR_POLARITY_LOW);
558 printf("$PIR: %d:%d INT%c routed to irq %d\n", bus, device,
559 pin - 1 + 'A', pci_link->pl_irq);
560 return (pci_link->pl_irq);
564 * Try to pick an interrupt for the specified link from the interrupts
568 pci_pir_choose_irq(struct pci_link *pci_link, int irqmask)
570 int i, irq, realmask;
572 /* XXX: Need to have a #define of known bad IRQs to also mask out? */
573 realmask = pci_link->pl_irqmask & irqmask;
575 return (PCI_INVALID_IRQ);
577 /* Find IRQ with lowest weight. */
578 irq = PCI_INVALID_IRQ;
579 for (i = 0; i < NUM_ISA_INTERRUPTS; i++) {
580 if (!(realmask & 1 << i))
582 if (irq == PCI_INVALID_IRQ ||
583 pir_interrupt_weight[i] < pir_interrupt_weight[irq])
586 if (bootverbose && PCI_INTERRUPT_VALID(irq)) {
587 printf("$PIR: Found IRQ %d for link %#x from ", irq,
589 pci_print_irqmask(realmask);
596 pci_print_irqmask(u_int16_t irqs)
605 for (i = 0; i < 16; i++, irqs >>= 1)
616 * Display link devices.
619 pci_pir_dump_links(void)
621 struct pci_link *pci_link;
623 printf("Link IRQ Rtd Ref IRQs\n");
624 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
625 printf("%#4x %3d %c %3d ", pci_link->pl_id,
626 pci_link->pl_irq, pci_link->pl_routed ? 'Y' : 'N',
627 pci_link->pl_references);
628 pci_print_irqmask(pci_link->pl_irqmask);
634 * See if any interrupts for a given PCI bus are routed in the PIR. Don't
635 * even bother looking if the BIOS doesn't support routing anyways. If we
636 * are probing a PCI-PCI bridge, then require_parse will be true and we should
637 * only succeed if a host-PCI bridge has already attached and parsed the PIR.
640 pci_pir_probe(int bus, int require_parse)
644 if (pci_route_table == NULL || (require_parse && !pir_parsed))
646 for (i = 0; i < pci_route_count; i++)
647 if (pci_route_table->pt_entry[i].pe_bus == bus)
653 * The driver for the new-bus pseudo device pir0 for the $PIR table.
657 pir_probe(device_t dev)
661 snprintf(buf, sizeof(buf), "PCI Interrupt Routing Table: %d Entries",
663 device_set_desc_copy(dev, buf);
668 pir_attach(device_t dev)
672 KASSERT(pir_device == NULL, ("Multiple pir devices"));
678 pir_resume_find_device(struct PIR_entry *entry, struct PIR_intpin *intpin,
681 struct pci_dev_lookup *pd;
683 pd = (struct pci_dev_lookup *)arg;
684 if (intpin->link != pd->link || pd->bus != -1)
686 pd->bus = entry->pe_bus;
687 pd->device = entry->pe_device;
688 pd->pin = intpin - entry->pe_intpin;
692 pir_resume(device_t dev)
694 struct pci_dev_lookup pd;
695 struct pci_link *pci_link;
698 /* Ask the BIOS to re-route each link that was already routed. */
699 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
700 if (!PCI_INTERRUPT_VALID(pci_link->pl_irq)) {
701 KASSERT(!pci_link->pl_routed,
702 ("link %#x is routed but has invalid PCI IRQ",
706 if (pci_link->pl_routed) {
708 pd.link = pci_link->pl_id;
709 pci_pir_walk_table(pir_resume_find_device, &pd);
710 KASSERT(pd.bus != -1,
711 ("did not find matching entry for link %#x in the $PIR table",
715 "Using %d.%d.INT%c to route link %#x to IRQ %d\n",
716 pd.bus, pd.device, pd.pin + 'A',
717 pci_link->pl_id, pci_link->pl_irq);
718 error = pci_pir_biosroute(pd.bus, pd.device, 0, pd.pin,
722 "ROUTE_INTERRUPT on resume for link %#x failed.\n",
729 static device_method_t pir_methods[] = {
730 /* Device interface */
731 DEVMETHOD(device_probe, pir_probe),
732 DEVMETHOD(device_attach, pir_attach),
733 DEVMETHOD(device_resume, pir_resume),
737 static driver_t pir_driver = {
743 static devclass_t pir_devclass;
745 DRIVER_MODULE(pir, legacy, pir_driver, pir_devclass, 0, 0);