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.
28 * __FBSDID("$FreeBSD: src/sys/i386/pci/pci_pir.c,v 1.120.2.1.4.1 2009/04/15 03:14:26 kensmith Exp $");
31 #include <sys/cdefs.h>
33 #include <sys/param.h>
34 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/module.h>
39 #include <sys/sysctl.h>
42 #include <vm/vm_param.h>
43 #include <machine/md_var.h>
44 #include <bus/pci/pcivar.h>
45 #include <bus/pci/pcireg.h>
46 #include "pci_cfgreg.h"
47 #include <machine/segments.h>
48 #include <machine/pc/bios.h>
50 #define NUM_ISA_INTERRUPTS 16
53 * A link device. Loosely based on the ACPI PCI link device. This doesn't
54 * try to support priorities for different ISA interrupts.
57 TAILQ_ENTRY(pci_link) pl_links;
65 struct pci_link_lookup {
66 struct pci_link **pci_link_ptr;
72 struct pci_dev_lookup {
79 typedef void pir_entry_handler(struct PIR_entry *entry,
80 struct PIR_intpin* intpin, void *arg);
82 static void pci_print_irqmask(u_int16_t irqs);
83 static int pci_pir_biosroute(int bus, int device, int func, int pin,
85 static int pci_pir_choose_irq(struct pci_link *pci_link, int irqmask);
86 static void pci_pir_create_links(struct PIR_entry *entry,
87 struct PIR_intpin *intpin, void *arg);
88 static void pci_pir_dump_links(void);
89 static struct pci_link *pci_pir_find_link(uint8_t link_id);
90 static void pci_pir_find_link_handler(struct PIR_entry *entry,
91 struct PIR_intpin *intpin, void *arg);
92 static void pci_pir_initial_irqs(struct PIR_entry *entry,
93 struct PIR_intpin *intpin, void *arg);
94 static void pci_pir_parse(void);
95 static uint8_t pci_pir_search_irq(int bus, int device, int pin);
96 static int pci_pir_valid_irq(struct pci_link *pci_link, int irq);
97 static void pci_pir_walk_table(pir_entry_handler *handler, void *arg);
99 static MALLOC_DEFINE(M_PIR, "$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 TUNABLE_INT("hw.pci.irq_override_mask", &pci_irq_override_mask);
116 SYSCTL_INT(_hw_pci, OID_AUTO, irq_override_mask, CTLFLAG_RD,
117 &pci_irq_override_mask, PCI_IRQ_OVERRIDE_MASK,
118 "Mask of allowed irqs to try to route when it has no good clue about\n"
119 "which irqs it should use.");
122 * Look for the interrupt routing table.
124 * We use PCI BIOS's PIR table if it's available. $PIR is the standard way
125 * to do this. Sadly, some machines are not standards conforming and have
126 * _PIR instead. We shrug and cope by looking for both.
131 struct PIR_table *pt;
136 /* Don't try if we've already found a table. */
137 if (pci_route_table != NULL)
140 /* Look for $PIR and then _PIR. */
141 sigaddr = bios_sigsearch(0, "$PIR", 4, 16, 0);
143 sigaddr = bios_sigsearch(0, "_PIR", 4, 16, 0);
147 /* If we found something, check the checksum and length. */
148 /* XXX - Use pmap_mapdev()? */
149 pt = (struct PIR_table *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
150 if (pt->pt_header.ph_length <= sizeof(struct PIR_header))
152 for (cv = (u_int8_t *)pt, ck = 0, i = 0;
153 i < (pt->pt_header.ph_length); i++)
158 /* Ok, we've got a valid table. */
159 pci_route_table = pt;
160 pci_route_count = (pt->pt_header.ph_length -
161 sizeof(struct PIR_header)) /
162 sizeof(struct PIR_entry);
166 * Find the pci_link structure for a given link ID.
168 static struct pci_link *
169 pci_pir_find_link(uint8_t link_id)
171 struct pci_link *pci_link;
173 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
174 if (pci_link->pl_id == link_id)
181 * Find the link device associated with a PCI device in the table.
184 pci_pir_find_link_handler(struct PIR_entry *entry, struct PIR_intpin *intpin,
187 struct pci_link_lookup *lookup;
189 lookup = (struct pci_link_lookup *)arg;
190 if (entry->pe_bus == lookup->bus &&
191 entry->pe_device == lookup->device &&
192 intpin - entry->pe_intpin == lookup->pin)
193 *lookup->pci_link_ptr = pci_pir_find_link(intpin->link);
197 * Check to see if a possible IRQ setting is valid.
200 pci_pir_valid_irq(struct pci_link *pci_link, int irq)
203 if (!PCI_INTERRUPT_VALID(irq))
205 return (pci_link->pl_irqmask & (1 << irq));
209 * Walk the $PIR executing the worker function for each valid intpin entry
210 * in the table. The handler is passed a pointer to both the entry and
211 * the intpin in the entry.
214 pci_pir_walk_table(pir_entry_handler *handler, void *arg)
216 struct PIR_entry *entry;
217 struct PIR_intpin *intpin;
220 entry = &pci_route_table->pt_entry[0];
221 for (i = 0; i < pci_route_count; i++, entry++) {
222 intpin = &entry->pe_intpin[0];
223 for (pin = 0; pin < 4; pin++, intpin++)
224 if (intpin->link != 0)
225 handler(entry, intpin, arg);
230 pci_pir_create_links(struct PIR_entry *entry, struct PIR_intpin *intpin,
233 struct pci_link *pci_link;
235 pci_link = pci_pir_find_link(intpin->link);
236 if (pci_link != NULL) {
237 pci_link->pl_references++;
238 if (intpin->irqs != pci_link->pl_irqmask) {
241 "$PIR: Entry %d.%d.INT%c has different mask for link %#x, merging\n",
242 entry->pe_bus, entry->pe_device,
243 (intpin - entry->pe_intpin) + 'A',
245 pci_link->pl_irqmask &= intpin->irqs;
248 pci_link = kmalloc(sizeof(struct pci_link), M_PIR, M_WAITOK);
249 pci_link->pl_id = intpin->link;
250 pci_link->pl_irqmask = intpin->irqs;
251 pci_link->pl_irq = PCI_INVALID_IRQ;
252 pci_link->pl_references = 1;
253 pci_link->pl_routed = 0;
254 TAILQ_INSERT_TAIL(&pci_links, pci_link, pl_links);
259 * Look to see if any of the function on the PCI device at bus/device have
260 * an interrupt routed to intpin 'pin' by the BIOS.
263 pci_pir_search_irq(int bus, int device, int pin)
266 uint8_t func, maxfunc;
268 /* See if we have a valid device at function 0. */
269 value = pci_cfgregread(bus, device, 0, PCIR_HDRTYPE, 1);
270 if ((value & PCIM_HDRTYPE) > PCI_MAXHDRTYPE)
271 return (PCI_INVALID_IRQ);
272 if (value & PCIM_MFDEV)
273 maxfunc = PCI_FUNCMAX;
277 /* Scan all possible functions at this device. */
278 for (func = 0; func <= maxfunc; func++) {
279 value = pci_cfgregread(bus, device, func, PCIR_DEVVENDOR, 4);
280 if (value == 0xffffffff)
282 value = pci_cfgregread(bus, device, func, PCIR_INTPIN, 1);
285 * See if it uses the pin in question. Note that the passed
286 * in pin uses 0 for A, .. 3 for D whereas the intpin
287 * register uses 0 for no interrupt, 1 for A, .. 4 for D.
289 if (value != pin + 1)
291 value = pci_cfgregread(bus, device, func, PCIR_INTLINE, 1);
294 "$PIR: Found matching pin for %d.%d.INT%c at func %d: %d\n",
295 bus, device, pin + 'A', func, value);
296 if (value != PCI_INVALID_IRQ)
299 return (PCI_INVALID_IRQ);
303 * Try to initialize IRQ based on this device's IRQ.
306 pci_pir_initial_irqs(struct PIR_entry *entry, struct PIR_intpin *intpin,
309 struct pci_link *pci_link;
312 pin = intpin - entry->pe_intpin;
313 pci_link = pci_pir_find_link(intpin->link);
314 irq = pci_pir_search_irq(entry->pe_bus, entry->pe_device, pin);
315 if (irq == PCI_INVALID_IRQ || irq == pci_link->pl_irq)
318 /* Don't trust any BIOS IRQs greater than 15. */
319 if (irq >= NUM_ISA_INTERRUPTS) {
321 "$PIR: Ignoring invalid BIOS IRQ %d from %d.%d.INT%c for link %#x\n",
322 irq, entry->pe_bus, entry->pe_device, pin + 'A',
328 * If we don't have an IRQ for this link yet, then we trust the
329 * BIOS, even if it seems invalid from the $PIR entries.
331 if (pci_link->pl_irq == PCI_INVALID_IRQ) {
332 if (!pci_pir_valid_irq(pci_link, irq))
334 "$PIR: Using invalid BIOS IRQ %d from %d.%d.INT%c for link %#x\n",
335 irq, entry->pe_bus, entry->pe_device, pin + 'A',
337 pci_link->pl_irq = irq;
338 pci_link->pl_routed = 1;
343 * We have an IRQ and it doesn't match the current IRQ for this
344 * link. If the new IRQ is invalid, then warn about it and ignore
345 * it. If the old IRQ is invalid and the new IRQ is valid, then
346 * prefer the new IRQ instead. If both IRQs are valid, then just
347 * use the first one. Note that if we ever get into this situation
348 * we are having to guess which setting the BIOS actually routed.
349 * Perhaps we should just give up instead.
351 if (!pci_pir_valid_irq(pci_link, irq)) {
353 "$PIR: BIOS IRQ %d for %d.%d.INT%c is not valid for link %#x\n",
354 irq, entry->pe_bus, entry->pe_device, pin + 'A',
356 } else if (!pci_pir_valid_irq(pci_link, pci_link->pl_irq)) {
358 "$PIR: Preferring valid BIOS IRQ %d from %d.%d.INT%c for link %#x to IRQ %d\n",
359 irq, entry->pe_bus, entry->pe_device, pin + 'A',
360 pci_link->pl_id, pci_link->pl_irq);
361 pci_link->pl_irq = irq;
362 pci_link->pl_routed = 1;
365 "$PIR: BIOS IRQ %d for %d.%d.INT%c does not match link %#x irq %d\n",
366 irq, entry->pe_bus, entry->pe_device, pin + 'A',
367 pci_link->pl_id, pci_link->pl_irq);
371 * Parse $PIR to enumerate link devices and attempt to determine their
372 * initial state. This could perhaps be cleaner if we had drivers for the
373 * various interrupt routers as they could read the initial IRQ for each
379 char tunable_buffer[64];
380 struct pci_link *pci_link;
383 /* Only parse once. */
388 /* Enumerate link devices. */
389 TAILQ_INIT(&pci_links);
390 pci_pir_walk_table(pci_pir_create_links, NULL);
392 kprintf("$PIR: Links after initial probe:\n");
393 pci_pir_dump_links();
397 * Check to see if the BIOS has already routed any of the links by
398 * checking each device connected to each link to see if it has a
401 pci_pir_walk_table(pci_pir_initial_irqs, NULL);
403 kprintf("$PIR: Links after initial IRQ discovery:\n");
404 pci_pir_dump_links();
408 * Allow the user to override the IRQ for a given link device. We
409 * allow invalid IRQs to be specified but warn about them. An IRQ
410 * of 255 or 0 clears any preset IRQ.
413 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
414 ksnprintf(tunable_buffer, sizeof(tunable_buffer),
415 "hw.pci.link.%#x.irq", pci_link->pl_id);
416 if (kgetenv_int(tunable_buffer, &irq) == 0)
419 irq = PCI_INVALID_IRQ;
420 if (irq != PCI_INVALID_IRQ &&
421 !pci_pir_valid_irq(pci_link, irq) && bootverbose)
423 "$PIR: Warning, IRQ %d for link %#x is not listed as valid\n",
424 irq, pci_link->pl_id);
425 pci_link->pl_routed = 0;
426 pci_link->pl_irq = irq;
429 if (bootverbose && i) {
430 kprintf("$PIR: Links after tunable overrides:\n");
431 pci_pir_dump_links();
435 * Build initial interrupt weights as well as bitmap of "known-good"
436 * IRQs that the BIOS has already used for PCI link devices.
438 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
439 if (!PCI_INTERRUPT_VALID(pci_link->pl_irq))
441 pir_bios_irqs |= 1 << pci_link->pl_irq;
442 pir_interrupt_weight[pci_link->pl_irq] +=
443 pci_link->pl_references;
446 kprintf("$PIR: IRQs used by BIOS: ");
447 pci_print_irqmask(pir_bios_irqs);
449 kprintf("$PIR: Interrupt Weights:\n[ ");
450 for (i = 0; i < NUM_ISA_INTERRUPTS; i++)
453 for (i = 0; i < NUM_ISA_INTERRUPTS; i++)
454 kprintf(" %3d", pir_interrupt_weight[i]);
460 * Use the PCI BIOS to route an interrupt for a given device.
463 * AX = PCIBIOS_ROUTE_INTERRUPT
465 * BL = device [7:3] / function [2:0]
467 * CL = Interrupt Pin (0x0A = A, ... 0x0D = D)
470 pci_pir_biosroute(int bus, int device, int func, int pin, int irq)
472 struct bios_regs args;
474 args.eax = PCIBIOS_ROUTE_INTERRUPT;
475 args.ebx = (bus << 8) | (device << 3) | func;
476 args.ecx = (irq << 8) | (0xa + pin);
477 return (bios32(&args, PCIbios.ventry, GSEL(GCODE_SEL, SEL_KPL)));
482 * Route a PCI interrupt using a link device from the $PIR.
485 pci_pir_route_interrupt(int bus, int device, int func, int pin)
487 struct pci_link_lookup lookup;
488 struct pci_link *pci_link;
491 if (pci_route_table == NULL)
492 return (PCI_INVALID_IRQ);
494 /* Lookup link device for this PCI device/pin. */
497 lookup.device = device;
498 lookup.pin = pin - 1;
499 lookup.pci_link_ptr = &pci_link;
500 pci_pir_walk_table(pci_pir_find_link_handler, &lookup);
501 if (pci_link == NULL) {
502 kprintf("$PIR: No matching entry for %d.%d.INT%c\n", bus,
503 device, pin - 1 + 'A');
504 return (PCI_INVALID_IRQ);
508 * Pick a new interrupt if we don't have one already. We look
509 * for an interrupt from several different sets. First, if
510 * this link only has one valid IRQ, use that. Second, we
511 * check the set of PCI only interrupts from the $PIR. Third,
512 * we check the set of known-good interrupts that the BIOS has
513 * already used. Lastly, we check the "all possible valid
516 if (!PCI_INTERRUPT_VALID(pci_link->pl_irq)) {
517 if (pci_link->pl_irqmask != 0 && powerof2(pci_link->pl_irqmask))
518 irq = ffs(pci_link->pl_irqmask) - 1;
520 irq = pci_pir_choose_irq(pci_link,
521 pci_route_table->pt_header.ph_pci_irqs);
522 if (!PCI_INTERRUPT_VALID(irq))
523 irq = pci_pir_choose_irq(pci_link, pir_bios_irqs);
524 if (!PCI_INTERRUPT_VALID(irq))
525 irq = pci_pir_choose_irq(pci_link,
526 pci_irq_override_mask);
527 if (!PCI_INTERRUPT_VALID(irq)) {
530 "$PIR: Failed to route interrupt for %d:%d INT%c\n",
531 bus, device, pin - 1 + 'A');
532 return (PCI_INVALID_IRQ);
534 pci_link->pl_irq = irq;
537 /* Ask the BIOS to route this IRQ if we haven't done so already. */
538 if (!pci_link->pl_routed) {
539 error = pci_pir_biosroute(bus, device, func, pin - 1,
542 /* Ignore errors when routing a unique interrupt. */
543 if (error && !powerof2(pci_link->pl_irqmask)) {
544 kprintf("$PIR: ROUTE_INTERRUPT failed.\n");
545 return (PCI_INVALID_IRQ);
547 pci_link->pl_routed = 1;
549 /* Ensure the interrupt is set to level/low trigger. */
550 KASSERT(pir_device != NULL, ("missing pir device"));
551 BUS_CONFIG_INTR(pir_device, pci_link->pl_irq,
552 INTR_TRIGGER_LEVEL, INTR_POLARITY_LOW);
555 kprintf("$PIR: %d:%d INT%c routed to irq %d\n", bus, device,
556 pin - 1 + 'A', pci_link->pl_irq);
557 return (pci_link->pl_irq);
561 * Try to pick an interrupt for the specified link from the interrupts
565 pci_pir_choose_irq(struct pci_link *pci_link, int irqmask)
567 int i, irq, realmask;
569 /* XXX: Need to have a #define of known bad IRQs to also mask out? */
570 realmask = pci_link->pl_irqmask & irqmask;
572 return (PCI_INVALID_IRQ);
574 /* Find IRQ with lowest weight. */
575 irq = PCI_INVALID_IRQ;
576 for (i = 0; i < NUM_ISA_INTERRUPTS; i++) {
577 if (!(realmask & 1 << i))
579 if (irq == PCI_INVALID_IRQ ||
580 pir_interrupt_weight[i] < pir_interrupt_weight[irq])
583 if (bootverbose && PCI_INTERRUPT_VALID(irq)) {
584 kprintf("$PIR: Found IRQ %d for link %#x from ", irq,
586 pci_print_irqmask(realmask);
593 pci_print_irqmask(u_int16_t irqs)
602 for (i = 0; i < 16; i++, irqs >>= 1)
613 * Display link devices.
616 pci_pir_dump_links(void)
618 struct pci_link *pci_link;
620 kprintf("Link IRQ Rtd Ref IRQs\n");
621 TAILQ_FOREACH(pci_link, &pci_links, pl_links) {
622 kprintf("%#4x %3d %c %3d ", pci_link->pl_id,
623 pci_link->pl_irq, pci_link->pl_routed ? 'Y' : 'N',
624 pci_link->pl_references);
625 pci_print_irqmask(pci_link->pl_irqmask);
631 * See if any interrupts for a given PCI bus are routed in the PIR. Don't
632 * even bother looking if the BIOS doesn't support routing anyways. If we
633 * are probing a PCI-PCI bridge, then require_parse will be true and we should
634 * only succeed if a host-PCI bridge has already attached and parsed the PIR.
637 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)
656 kprintf("pir probe\n");
657 ksnprintf(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);