xref: /freebsd/sys/i386/pci/pci_pir.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
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  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  *
30  */
31 
32 #include <sys/param.h>		/* XXX trim includes */
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 #include <sys/malloc.h>
38 #include <vm/vm.h>
39 #include <vm/pmap.h>
40 #include <machine/md_var.h>
41 #include <pci/pcivar.h>
42 #include <pci/pcireg.h>
43 #include <isa/isavar.h>
44 #include <machine/nexusvar.h>
45 #include <machine/pci_cfgreg.h>
46 #include <machine/segments.h>
47 #include <machine/pc/bios.h>
48 
49 #include "pcib_if.h"
50 
51 static int cfgmech;
52 static int devmax;
53 static int usebios;
54 
55 static int	pci_cfgintr_unique(struct PIR_entry *pe, int pin);
56 static int	pci_cfgintr_linked(struct PIR_entry *pe, int pin);
57 static int	pci_cfgintr_search(struct PIR_entry *pe, int bus, int device, int matchpin, int pin);
58 static int	pci_cfgintr_virgin(struct PIR_entry *pe, int pin);
59 
60 static int	pcibios_cfgread(int bus, int slot, int func, int reg, int bytes);
61 static void	pcibios_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes);
62 static int	pcibios_cfgopen(void);
63 static int	pcireg_cfgread(int bus, int slot, int func, int reg, int bytes);
64 static void	pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes);
65 static int	pcireg_cfgopen(void);
66 
67 static struct PIR_table	*pci_route_table;
68 static int		pci_route_count;
69 
70 /*
71  * Initialise access to PCI configuration space
72  */
73 int
74 pci_cfgregopen(void)
75 {
76     static int			opened = 0;
77     u_long			sigaddr;
78     static struct PIR_table	*pt;
79     u_int8_t			ck, *cv;
80     int				i;
81 
82     if (opened)
83 	return(1);
84 
85     if (pcibios_cfgopen() != 0) {
86 	usebios = 1;
87     } else if (pcireg_cfgopen() != 0) {
88 	usebios = 0;
89     } else {
90 	return(0);
91     }
92 
93     /*
94      * Look for the interrupt routing table.
95      */
96     /* XXX use PCI BIOS if it's available */
97 
98     if ((pt == NULL) && ((sigaddr = bios_sigsearch(0, "$PIR", 4, 16, 0)) != 0)) {
99 	pt = (struct PIR_table *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
100 	for (cv = (u_int8_t *)pt, ck = 0, i = 0; i < (pt->pt_header.ph_length); i++) {
101 	    ck += cv[i];
102 	}
103 	if (ck == 0) {
104 	    pci_route_table = pt;
105 	    pci_route_count = (pt->pt_header.ph_length - sizeof(struct PIR_header)) / sizeof(struct PIR_entry);
106 	    printf("Using $PIR table, %d entries at %p\n", pci_route_count, pci_route_table);
107 	}
108     }
109 
110     opened = 1;
111     return(1);
112 }
113 
114 /*
115  * Read configuration space register
116  */
117 u_int32_t
118 pci_cfgregread(int bus, int slot, int func, int reg, int bytes)
119 {
120     return(usebios ?
121 	   pcibios_cfgread(bus, slot, func, reg, bytes) :
122 	   pcireg_cfgread(bus, slot, func, reg, bytes));
123 }
124 
125 /*
126  * Write configuration space register
127  */
128 void
129 pci_cfgregwrite(int bus, int slot, int func, int reg, u_int32_t data, int bytes)
130 {
131     return(usebios ?
132 	   pcibios_cfgwrite(bus, slot, func, reg, data, bytes) :
133 	   pcireg_cfgwrite(bus, slot, func, reg, data, bytes));
134 }
135 
136 /*
137  * Route a PCI interrupt
138  *
139  * XXX we don't do anything "right" with the function number in the PIR table
140  *     (because the consumer isn't currently passing it in).  We don't care
141  *     anyway, due to the way PCI interrupts are assigned.
142  */
143 int
144 pci_cfgintr(int bus, int device, int pin)
145 {
146     struct PIR_entry	*pe;
147     int			i, irq;
148     struct bios_regs	args;
149 
150     if ((bus < 0) || (bus > 255) || (device < 0) || (device > 255) ||
151       (pin < 1) || (pin > 4))
152 	return(255);
153 
154     /*
155      * Scan the entry table for a contender
156      */
157     for (i = 0, pe = &pci_route_table->pt_entry[0]; i < pci_route_count; i++, pe++) {
158 	if ((bus != pe->pe_bus) || (device != pe->pe_device))
159 	    continue;
160 
161 	irq = pci_cfgintr_unique(pe, pin);
162 	if (irq == 255)
163 	    irq = pci_cfgintr_linked(pe, pin);
164 	if (irq == 255)
165 	    irq = pci_cfgintr_virgin(pe, pin);
166 
167 	if (irq == 255)
168 	    break;
169 
170 
171 	/*
172 	 * Ask the BIOS to route the interrupt
173 	 */
174 	args.eax = PCIBIOS_ROUTE_INTERRUPT;
175 	args.ebx = (bus << 8) | (device << 3);
176 	args.ecx = (irq << 8) | (0xa + pin - 1);	/* pin value is 0xa - 0xd */
177 	bios32(&args, PCIbios.ventry, GSEL(GCODE_SEL, SEL_KPL));
178 
179 	/*
180 	 * XXX if it fails, we should try to smack the router hardware directly
181 	 */
182 
183 	printf("pci_cfgintr: %d:%d INT%c routed to irq %d\n",
184 	       bus, device, 'A' + pin - 1, irq);
185 	return(irq);
186     }
187 
188     printf("pci_cfgintr: can't route an interrupt to %d:%d INT%c\n", bus, device, 'A' + pin - 1);
189     return(255);
190 }
191 
192 /*
193  * Look to see if the routing table claims this pin is uniquely routed.
194  */
195 static int
196 pci_cfgintr_unique(struct PIR_entry *pe, int pin)
197 {
198     int		irq;
199 
200     if (powerof2(pe->pe_intpin[pin - 1].irqs)) {
201 	irq = ffs(pe->pe_intpin[pin - 1].irqs) - 1;
202 	printf("pci_cfgintr_unique: hard-routed to irq %d\n", irq);
203 	return(irq);
204     }
205     return(255);
206 }
207 
208 /*
209  * Look for another device which shares the same link byte and
210  * already has a unique IRQ, or which has had one routed already.
211  */
212 static int
213 pci_cfgintr_linked(struct PIR_entry *pe, int pin)
214 {
215     struct PIR_entry	*oe;
216     struct PIR_intpin	*pi;
217     int			i, j, irq;
218 
219     /*
220      * Scan table slots.
221      */
222     for (i = 0, oe = &pci_route_table->pt_entry[0]; i < pci_route_count; i++, oe++) {
223 
224 	/* scan interrupt pins */
225 	for (j = 0, pi = &oe->pe_intpin[0]; j < 4; j++, pi++) {
226 
227 	    /* don't look at the entry we're trying to match with */
228 	    if ((pe == oe) && (i == (pin - 1)))
229 		continue;
230 
231 	    /* compare link bytes */
232 	    if (pi->link != pe->pe_intpin[pin - 1].link)
233 		continue;
234 
235 	    /* link destination mapped to a unique interrupt? */
236 	    if (powerof2(pi->irqs)) {
237 		irq = ffs(pi->irqs) - 1;
238 		printf("pci_cfgintr_linked: linked (%x) to hard-routed irq %d\n",
239 		       pi->link, irq);
240 		return(irq);
241 	    }
242 
243 	    /* look for the real PCI device that matches this table entry */
244 	    if ((irq = pci_cfgintr_search(pe, oe->pe_bus, oe->pe_device, j, pin)) != 255)
245 		return(irq);
246 	}
247     }
248     return(255);
249 }
250 
251 /*
252  * Scan for the real PCI device at (bus)/(device) using intpin (matchpin) and
253  * see if it has already been assigned an interrupt.
254  */
255 static int
256 pci_cfgintr_search(struct PIR_entry *pe, int bus, int device, int matchpin, int pin)
257 {
258     devclass_t		pci_devclass;
259     device_t		*pci_devices;
260     int			pci_count;
261     device_t		*pci_children;
262     int			pci_childcount;
263     device_t		*busp, *childp;
264     int			i, j, irq;
265 
266     /*
267      * Find all the PCI busses.
268      */
269     pci_count = 0;
270     if ((pci_devclass = devclass_find("pci")) != NULL)
271 	devclass_get_devices(pci_devclass, &pci_devices, &pci_count);
272 
273     /*
274      * Scan all the PCI busses/devices looking for this one.
275      */
276     for (i = 0, busp = pci_devices; i < pci_count; i++, busp++) {
277 	pci_childcount = 0;
278 	device_get_children(*busp, &pci_children, &pci_childcount);
279 
280 	for (j = 0, childp = pci_children; j < pci_childcount; j++, childp++) {
281 	    if ((pci_get_bus(*childp) == bus) &&
282 		(pci_get_slot(*childp) == device) &&
283 		(pci_get_intpin(*childp) == matchpin) &&
284 		((irq = pci_get_irq(*childp)) != 255)) {
285 		printf("pci_cfgintr_search: linked (%x) to configured irq %d at %d:%d:%d\n",
286 		       irq, pe->pe_intpin[pin - 1].link,
287 		       pci_get_bus(*childp), pci_get_slot(*childp), pci_get_function(*childp));
288 		return(irq);
289 	    }
290 	}
291     }
292     return(255);
293 }
294 
295 /*
296  * Pick a suitable IRQ from those listed as routable to this device.
297  */
298 static int
299 pci_cfgintr_virgin(struct PIR_entry *pe, int pin)
300 {
301     int		irq, ibit;
302 
303     /* first scan the set of PCI-only interrupts and see if any of these are routable */
304     for (irq = 0; irq < 16; irq++) {
305 	ibit = (1 << irq);
306 
307 	/* can we use this interrupt? */
308 	if ((pci_route_table->pt_header.ph_pci_irqs & ibit) &&
309 	    (pe->pe_intpin[pin - 1].irqs & ibit)) {
310 	    printf("pci_cfgintr_virgin: using routable PCI-only interrupt %d\n", irq);
311 	    return(irq);
312 	}
313     }
314 
315     /* life is tough, so just pick an interrupt */
316     for (irq = 0; irq < 16; irq++) {
317 	ibit = (1 << irq);
318 
319 	if (pe->pe_intpin[pin - 1].irqs & ibit) {
320 	    printf("pci_cfgintr_virgin: using routable interrupt %d\n", irq);
321 	    return(irq);
322 	}
323     }
324     return(255);
325 }
326 
327 
328 /*
329  * Config space access using BIOS functions
330  */
331 static int
332 pcibios_cfgread(int bus, int slot, int func, int reg, int bytes)
333 {
334     struct bios_regs args;
335     u_int mask;
336 
337     switch(bytes) {
338     case 1:
339 	args.eax = PCIBIOS_READ_CONFIG_BYTE;
340 	mask = 0xff;
341 	break;
342     case 2:
343 	args.eax = PCIBIOS_READ_CONFIG_WORD;
344 	mask = 0xffff;
345 	break;
346     case 4:
347 	args.eax = PCIBIOS_READ_CONFIG_DWORD;
348 	mask = 0xffffffff;
349 	break;
350     default:
351 	return(-1);
352     }
353     args.ebx = (bus << 8) | (slot << 3) | func;
354     args.edi = reg;
355     bios32(&args, PCIbios.ventry, GSEL(GCODE_SEL, SEL_KPL));
356     /* check call results? */
357     return(args.ecx & mask);
358 }
359 
360 static void
361 pcibios_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes)
362 {
363     struct bios_regs args;
364 
365     switch(bytes) {
366     case 1:
367 	args.eax = PCIBIOS_WRITE_CONFIG_BYTE;
368 	break;
369     case 2:
370 	args.eax = PCIBIOS_WRITE_CONFIG_WORD;
371 	break;
372     case 4:
373 	args.eax = PCIBIOS_WRITE_CONFIG_DWORD;
374 	break;
375     default:
376 	return;
377     }
378     args.ebx = (bus << 8) | (slot << 3) | func;
379     args.ecx = data;
380     args.edi = reg;
381     bios32(&args, PCIbios.ventry, GSEL(GCODE_SEL, SEL_KPL));
382 }
383 
384 /*
385  * Determine whether there is a PCI BIOS present
386  */
387 static int
388 pcibios_cfgopen(void)
389 {
390     /* check for a found entrypoint */
391     return(PCIbios.entry != 0);
392 }
393 
394 /*
395  * Configuration space access using direct register operations
396  */
397 
398 /* enable configuration space accesses and return data port address */
399 static int
400 pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes)
401 {
402     int dataport = 0;
403 
404     if (bus <= PCI_BUSMAX
405 	&& slot < devmax
406 	&& func <= PCI_FUNCMAX
407 	&& reg <= PCI_REGMAX
408 	&& bytes != 3
409 	&& (unsigned) bytes <= 4
410 	&& (reg & (bytes -1)) == 0) {
411 	switch (cfgmech) {
412 	case 1:
413 	    outl(CONF1_ADDR_PORT, (1 << 31)
414 		 | (bus << 16) | (slot << 11)
415 		 | (func << 8) | (reg & ~0x03));
416 	    dataport = CONF1_DATA_PORT + (reg & 0x03);
417 	    break;
418 	case 2:
419 	    outb(CONF2_ENABLE_PORT, 0xf0 | (func << 1));
420 	    outb(CONF2_FORWARD_PORT, bus);
421 	    dataport = 0xc000 | (slot << 8) | reg;
422 	    break;
423 	}
424     }
425     return (dataport);
426 }
427 
428 /* disable configuration space accesses */
429 static void
430 pci_cfgdisable(void)
431 {
432     switch (cfgmech) {
433     case 1:
434 	outl(CONF1_ADDR_PORT, 0);
435 	break;
436     case 2:
437 	outb(CONF2_ENABLE_PORT, 0);
438 	outb(CONF2_FORWARD_PORT, 0);
439 	break;
440     }
441 }
442 
443 static int
444 pcireg_cfgread(int bus, int slot, int func, int reg, int bytes)
445 {
446     int data = -1;
447     int port;
448 
449     port = pci_cfgenable(bus, slot, func, reg, bytes);
450 
451     if (port != 0) {
452 	switch (bytes) {
453 	case 1:
454 	    data = inb(port);
455 	    break;
456 	case 2:
457 	    data = inw(port);
458 	    break;
459 	case 4:
460 	    data = inl(port);
461 	    break;
462 	}
463 	pci_cfgdisable();
464     }
465     return (data);
466 }
467 
468 static void
469 pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes)
470 {
471     int port;
472 
473     port = pci_cfgenable(bus, slot, func, reg, bytes);
474     if (port != 0) {
475 	switch (bytes) {
476 	case 1:
477 	    outb(port, data);
478 	    break;
479 	case 2:
480 	    outw(port, data);
481 	    break;
482 	case 4:
483 	    outl(port, data);
484 	    break;
485 	}
486 	pci_cfgdisable();
487     }
488 }
489 
490 /* check whether the configuration mechanism has been correctly identified */
491 static int
492 pci_cfgcheck(int maxdev)
493 {
494     u_char device;
495 
496     if (bootverbose)
497 	printf("pci_cfgcheck:\tdevice ");
498 
499     for (device = 0; device < maxdev; device++) {
500 	unsigned id, class, header;
501 	if (bootverbose)
502 	    printf("%d ", device);
503 
504 	id = inl(pci_cfgenable(0, device, 0, 0, 4));
505 	if (id == 0 || id == -1)
506 	    continue;
507 
508 	class = inl(pci_cfgenable(0, device, 0, 8, 4)) >> 8;
509 	if (bootverbose)
510 	    printf("[class=%06x] ", class);
511 	if (class == 0 || (class & 0xf870ff) != 0)
512 	    continue;
513 
514 	header = inb(pci_cfgenable(0, device, 0, 14, 1));
515 	if (bootverbose)
516 	    printf("[hdr=%02x] ", header);
517 	if ((header & 0x7e) != 0)
518 	    continue;
519 
520 	if (bootverbose)
521 	    printf("is there (id=%08x)\n", id);
522 
523 	pci_cfgdisable();
524 	return (1);
525     }
526     if (bootverbose)
527 	printf("-- nothing found\n");
528 
529     pci_cfgdisable();
530     return (0);
531 }
532 
533 static int
534 pcireg_cfgopen(void)
535 {
536     unsigned long mode1res,oldval1;
537     unsigned char mode2res,oldval2;
538 
539     oldval1 = inl(CONF1_ADDR_PORT);
540 
541     if (bootverbose) {
542 	printf("pci_open(1):\tmode 1 addr port (0x0cf8) is 0x%08lx\n",
543 	       oldval1);
544     }
545 
546     if ((oldval1 & CONF1_ENABLE_MSK) == 0) {
547 
548 	cfgmech = 1;
549 	devmax = 32;
550 
551 	outl(CONF1_ADDR_PORT, CONF1_ENABLE_CHK);
552 	outb(CONF1_ADDR_PORT +3, 0);
553 	mode1res = inl(CONF1_ADDR_PORT);
554 	outl(CONF1_ADDR_PORT, oldval1);
555 
556 	if (bootverbose)
557 	    printf("pci_open(1a):\tmode1res=0x%08lx (0x%08lx)\n",
558 		   mode1res, CONF1_ENABLE_CHK);
559 
560 	if (mode1res) {
561 	    if (pci_cfgcheck(32))
562 		return (cfgmech);
563 	}
564 
565 	outl(CONF1_ADDR_PORT, CONF1_ENABLE_CHK1);
566 	mode1res = inl(CONF1_ADDR_PORT);
567 	outl(CONF1_ADDR_PORT, oldval1);
568 
569 	if (bootverbose)
570 	    printf("pci_open(1b):\tmode1res=0x%08lx (0x%08lx)\n",
571 		   mode1res, CONF1_ENABLE_CHK1);
572 
573 	if ((mode1res & CONF1_ENABLE_MSK1) == CONF1_ENABLE_RES1) {
574 	    if (pci_cfgcheck(32))
575 		return (cfgmech);
576 	}
577     }
578 
579     oldval2 = inb(CONF2_ENABLE_PORT);
580 
581     if (bootverbose) {
582 	printf("pci_open(2):\tmode 2 enable port (0x0cf8) is 0x%02x\n",
583 	       oldval2);
584     }
585 
586     if ((oldval2 & 0xf0) == 0) {
587 
588 	cfgmech = 2;
589 	devmax = 16;
590 
591 	outb(CONF2_ENABLE_PORT, CONF2_ENABLE_CHK);
592 	mode2res = inb(CONF2_ENABLE_PORT);
593 	outb(CONF2_ENABLE_PORT, oldval2);
594 
595 	if (bootverbose)
596 	    printf("pci_open(2a):\tmode2res=0x%02x (0x%02x)\n",
597 		   mode2res, CONF2_ENABLE_CHK);
598 
599 	if (mode2res == CONF2_ENABLE_RES) {
600 	    if (bootverbose)
601 		printf("pci_open(2a):\tnow trying mechanism 2\n");
602 
603 	    if (pci_cfgcheck(16))
604 		return (cfgmech);
605 	}
606     }
607 
608     cfgmech = 0;
609     devmax = 0;
610     return (cfgmech);
611 }
612 
613