xref: /freebsd/sys/i386/pci/pci_cfgreg.c (revision 6356dba0b403daa023dec24559ab1f8e602e4f14)
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, Scott Long <scottl@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("$FreeBSD$");
32 
33 #include "opt_xbox.h"
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 #include <sys/lock.h>
39 #include <sys/mutex.h>
40 #include <sys/malloc.h>
41 #include <sys/queue.h>
42 #include <dev/pci/pcivar.h>
43 #include <dev/pci/pcireg.h>
44 #include <machine/pci_cfgreg.h>
45 #include <machine/pc/bios.h>
46 
47 #include <vm/vm.h>
48 #include <vm/vm_param.h>
49 #include <vm/vm_kern.h>
50 #include <vm/vm_extern.h>
51 #include <vm/pmap.h>
52 #include <machine/pmap.h>
53 
54 #ifdef XBOX
55 #include <machine/xbox.h>
56 #endif
57 
58 #define PRVERB(a) do {							\
59 	if (bootverbose)						\
60 		printf a ;						\
61 } while(0)
62 
63 #define PCIE_CACHE 8
64 struct pcie_cfg_elem {
65 	TAILQ_ENTRY(pcie_cfg_elem)	elem;
66 	vm_offset_t	vapage;
67 	vm_paddr_t	papage;
68 };
69 
70 enum {
71 	CFGMECH_NONE = 0,
72 	CFGMECH_1,
73 	CFGMECH_2,
74 	CFGMECH_PCIE,
75 };
76 
77 static TAILQ_HEAD(pcie_cfg_list, pcie_cfg_elem) pcie_list[MAXCPU];
78 static uint64_t pcie_base;
79 static int pcie_minbus, pcie_maxbus;
80 static int cfgmech;
81 static int devmax;
82 static struct mtx pcicfg_mtx;
83 
84 static int	pcireg_cfgread(int bus, int slot, int func, int reg, int bytes);
85 static void	pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes);
86 #ifndef XEN
87 static int	pcireg_cfgopen(void);
88 #endif
89 static int	pciereg_cfgread(int bus, unsigned slot, unsigned func,
90 		    unsigned reg, unsigned bytes);
91 static void	pciereg_cfgwrite(int bus, unsigned slot, unsigned func,
92 		    unsigned reg, int data, unsigned bytes);
93 
94 /*
95  * Some BIOS writers seem to want to ignore the spec and put
96  * 0 in the intline rather than 255 to indicate none.  Some use
97  * numbers in the range 128-254 to indicate something strange and
98  * apparently undocumented anywhere.  Assume these are completely bogus
99  * and map them to 255, which means "none".
100  */
101 static __inline int
102 pci_i386_map_intline(int line)
103 {
104 	if (line == 0 || line >= 128)
105 		return (PCI_INVALID_IRQ);
106 	return (line);
107 }
108 
109 #ifndef XEN
110 static u_int16_t
111 pcibios_get_version(void)
112 {
113 	struct bios_regs args;
114 
115 	if (PCIbios.ventry == 0) {
116 		PRVERB(("pcibios: No call entry point\n"));
117 		return (0);
118 	}
119 	args.eax = PCIBIOS_BIOS_PRESENT;
120 	if (bios32(&args, PCIbios.ventry, GSEL(GCODE_SEL, SEL_KPL))) {
121 		PRVERB(("pcibios: BIOS_PRESENT call failed\n"));
122 		return (0);
123 	}
124 	if (args.edx != 0x20494350) {
125 		PRVERB(("pcibios: BIOS_PRESENT didn't return 'PCI ' in edx\n"));
126 		return (0);
127 	}
128 	return (args.ebx & 0xffff);
129 }
130 #endif
131 
132 /*
133  * Initialise access to PCI configuration space
134  */
135 int
136 pci_cfgregopen(void)
137 {
138 #ifdef XEN
139 	return (0);
140 #else
141 	static int		opened = 0;
142 	uint64_t		pciebar;
143 	u_int16_t		vid, did;
144 	u_int16_t		v;
145 
146 	if (opened)
147 		return (1);
148 
149 	if (cfgmech == CFGMECH_NONE && pcireg_cfgopen() == 0)
150 		return (0);
151 
152 	v = pcibios_get_version();
153 	if (v > 0)
154 		PRVERB(("pcibios: BIOS version %x.%02x\n", (v & 0xff00) >> 8,
155 		    v & 0xff));
156 	mtx_init(&pcicfg_mtx, "pcicfg", NULL, MTX_SPIN);
157 	opened = 1;
158 
159 	/* $PIR requires PCI BIOS 2.10 or greater. */
160 	if (v >= 0x0210)
161 		pci_pir_open();
162 
163 	if (cfgmech == CFGMECH_PCIE)
164 		return (1);
165 
166 	/*
167 	 * Grope around in the PCI config space to see if this is a
168 	 * chipset that is capable of doing memory-mapped config cycles.
169 	 * This also implies that it can do PCIe extended config cycles.
170 	 */
171 
172 	/* Check for supported chipsets */
173 	vid = pci_cfgregread(0, 0, 0, PCIR_VENDOR, 2);
174 	did = pci_cfgregread(0, 0, 0, PCIR_DEVICE, 2);
175 	switch (vid) {
176 	case 0x8086:
177 		switch (did) {
178 		case 0x3590:
179 		case 0x3592:
180 			/* Intel 7520 or 7320 */
181 			pciebar = pci_cfgregread(0, 0, 0, 0xce, 2) << 16;
182 			pcie_cfgregopen(pciebar, 0, 255);
183 			break;
184 		case 0x2580:
185 		case 0x2584:
186 		case 0x2590:
187 			/* Intel 915, 925, or 915GM */
188 			pciebar = pci_cfgregread(0, 0, 0, 0x48, 4);
189 			pcie_cfgregopen(pciebar, 0, 255);
190 			break;
191 		}
192 	}
193 
194 	return(1);
195 #endif
196 }
197 
198 /*
199  * Read configuration space register
200  */
201 u_int32_t
202 pci_cfgregread(int bus, int slot, int func, int reg, int bytes)
203 {
204 	uint32_t line;
205 
206 	/*
207 	 * Some BIOS writers seem to want to ignore the spec and put
208 	 * 0 in the intline rather than 255 to indicate none.  The rest of
209 	 * the code uses 255 as an invalid IRQ.
210 	 */
211 	if (reg == PCIR_INTLINE && bytes == 1) {
212 		line = pcireg_cfgread(bus, slot, func, PCIR_INTLINE, 1);
213 		return (pci_i386_map_intline(line));
214 	}
215 	return (pcireg_cfgread(bus, slot, func, reg, bytes));
216 }
217 
218 /*
219  * Write configuration space register
220  */
221 void
222 pci_cfgregwrite(int bus, int slot, int func, int reg, u_int32_t data, int bytes)
223 {
224 
225 	pcireg_cfgwrite(bus, slot, func, reg, data, bytes);
226 }
227 
228 /*
229  * Configuration space access using direct register operations
230  */
231 
232 /* enable configuration space accesses and return data port address */
233 static int
234 pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes)
235 {
236 	int dataport = 0;
237 
238 #ifdef XBOX
239 	if (arch_i386_is_xbox) {
240 		/*
241 		 * The Xbox MCPX chipset is a derivative of the nForce 1
242 		 * chipset. It almost has the same bus layout; some devices
243 		 * cannot be used, because they have been removed.
244 		 */
245 
246 		/*
247 		 * Devices 00:00.1 and 00:00.2 used to be memory controllers on
248 		 * the nForce chipset, but on the Xbox, using them will lockup
249 		 * the chipset.
250 		 */
251 		if (bus == 0 && slot == 0 && (func == 1 || func == 2))
252 			return dataport;
253 
254 		/*
255 		 * Bus 1 only contains a VGA controller at 01:00.0. When you try
256 		 * to probe beyond that device, you only get garbage, which
257 		 * could cause lockups.
258 		 */
259 		if (bus == 1 && (slot != 0 || func != 0))
260 			return dataport;
261 
262 		/*
263 		 * Bus 2 used to contain the AGP controller, but the Xbox MCPX
264 		 * doesn't have one. Probing it can cause lockups.
265 		 */
266 		if (bus >= 2)
267 			return dataport;
268 	}
269 #endif
270 
271 	if (bus <= PCI_BUSMAX
272 	    && slot < devmax
273 	    && func <= PCI_FUNCMAX
274 	    && reg <= PCI_REGMAX
275 	    && bytes != 3
276 	    && (unsigned) bytes <= 4
277 	    && (reg & (bytes - 1)) == 0) {
278 		switch (cfgmech) {
279 		case CFGMECH_1:
280 			outl(CONF1_ADDR_PORT, (1 << 31)
281 			    | (bus << 16) | (slot << 11)
282 			    | (func << 8) | (reg & ~0x03));
283 			dataport = CONF1_DATA_PORT + (reg & 0x03);
284 			break;
285 		case CFGMECH_2:
286 			outb(CONF2_ENABLE_PORT, 0xf0 | (func << 1));
287 			outb(CONF2_FORWARD_PORT, bus);
288 			dataport = 0xc000 | (slot << 8) | reg;
289 			break;
290 		}
291 	}
292 	return (dataport);
293 }
294 
295 /* disable configuration space accesses */
296 static void
297 pci_cfgdisable(void)
298 {
299 	switch (cfgmech) {
300 	case CFGMECH_1:
301 		/*
302 		 * Do nothing for the config mechanism 1 case.
303 		 * Writing a 0 to the address port can apparently
304 		 * confuse some bridges and cause spurious
305 		 * access failures.
306 		 */
307 		break;
308 	case CFGMECH_2:
309 		outb(CONF2_ENABLE_PORT, 0);
310 		break;
311 	}
312 }
313 
314 static int
315 pcireg_cfgread(int bus, int slot, int func, int reg, int bytes)
316 {
317 	int data = -1;
318 	int port;
319 
320 	if (cfgmech == CFGMECH_PCIE) {
321 		data = pciereg_cfgread(bus, slot, func, reg, bytes);
322 		return (data);
323 	}
324 
325 	mtx_lock_spin(&pcicfg_mtx);
326 	port = pci_cfgenable(bus, slot, func, reg, bytes);
327 	if (port != 0) {
328 		switch (bytes) {
329 		case 1:
330 			data = inb(port);
331 			break;
332 		case 2:
333 			data = inw(port);
334 			break;
335 		case 4:
336 			data = inl(port);
337 			break;
338 		}
339 		pci_cfgdisable();
340 	}
341 	mtx_unlock_spin(&pcicfg_mtx);
342 	return (data);
343 }
344 
345 static void
346 pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes)
347 {
348 	int port;
349 
350 	if (cfgmech == CFGMECH_PCIE) {
351 		pciereg_cfgwrite(bus, slot, func, reg, data, bytes);
352 		return;
353 	}
354 
355 	mtx_lock_spin(&pcicfg_mtx);
356 	port = pci_cfgenable(bus, slot, func, reg, bytes);
357 	if (port != 0) {
358 		switch (bytes) {
359 		case 1:
360 			outb(port, data);
361 			break;
362 		case 2:
363 			outw(port, data);
364 			break;
365 		case 4:
366 			outl(port, data);
367 			break;
368 		}
369 		pci_cfgdisable();
370 	}
371 	mtx_unlock_spin(&pcicfg_mtx);
372 }
373 
374 #ifndef XEN
375 /* check whether the configuration mechanism has been correctly identified */
376 static int
377 pci_cfgcheck(int maxdev)
378 {
379 	uint32_t id, class;
380 	uint8_t header;
381 	uint8_t device;
382 	int port;
383 
384 	if (bootverbose)
385 		printf("pci_cfgcheck:\tdevice ");
386 
387 	for (device = 0; device < maxdev; device++) {
388 		if (bootverbose)
389 			printf("%d ", device);
390 
391 		port = pci_cfgenable(0, device, 0, 0, 4);
392 		id = inl(port);
393 		if (id == 0 || id == 0xffffffff)
394 			continue;
395 
396 		port = pci_cfgenable(0, device, 0, 8, 4);
397 		class = inl(port) >> 8;
398 		if (bootverbose)
399 			printf("[class=%06x] ", class);
400 		if (class == 0 || (class & 0xf870ff) != 0)
401 			continue;
402 
403 		port = pci_cfgenable(0, device, 0, 14, 1);
404 		header = inb(port);
405 		if (bootverbose)
406 			printf("[hdr=%02x] ", header);
407 		if ((header & 0x7e) != 0)
408 			continue;
409 
410 		if (bootverbose)
411 			printf("is there (id=%08x)\n", id);
412 
413 		pci_cfgdisable();
414 		return (1);
415 	}
416 	if (bootverbose)
417 		printf("-- nothing found\n");
418 
419 	pci_cfgdisable();
420 	return (0);
421 }
422 
423 static int
424 pcireg_cfgopen(void)
425 {
426 	uint32_t mode1res, oldval1;
427 	uint8_t mode2res, oldval2;
428 
429 	/* Check for type #1 first. */
430 	oldval1 = inl(CONF1_ADDR_PORT);
431 
432 	if (bootverbose) {
433 		printf("pci_open(1):\tmode 1 addr port (0x0cf8) is 0x%08x\n",
434 		    oldval1);
435 	}
436 
437 	cfgmech = CFGMECH_1;
438 	devmax = 32;
439 
440 	outl(CONF1_ADDR_PORT, CONF1_ENABLE_CHK);
441 	DELAY(1);
442 	mode1res = inl(CONF1_ADDR_PORT);
443 	outl(CONF1_ADDR_PORT, oldval1);
444 
445 	if (bootverbose)
446 		printf("pci_open(1a):\tmode1res=0x%08x (0x%08lx)\n",  mode1res,
447 		    CONF1_ENABLE_CHK);
448 
449 	if (mode1res) {
450 		if (pci_cfgcheck(32))
451 			return (cfgmech);
452 	}
453 
454 	outl(CONF1_ADDR_PORT, CONF1_ENABLE_CHK1);
455 	mode1res = inl(CONF1_ADDR_PORT);
456 	outl(CONF1_ADDR_PORT, oldval1);
457 
458 	if (bootverbose)
459 		printf("pci_open(1b):\tmode1res=0x%08x (0x%08lx)\n",  mode1res,
460 		    CONF1_ENABLE_CHK1);
461 
462 	if ((mode1res & CONF1_ENABLE_MSK1) == CONF1_ENABLE_RES1) {
463 		if (pci_cfgcheck(32))
464 			return (cfgmech);
465 	}
466 
467 	/* Type #1 didn't work, so try type #2. */
468 	oldval2 = inb(CONF2_ENABLE_PORT);
469 
470 	if (bootverbose) {
471 		printf("pci_open(2):\tmode 2 enable port (0x0cf8) is 0x%02x\n",
472 		    oldval2);
473 	}
474 
475 	if ((oldval2 & 0xf0) == 0) {
476 
477 		cfgmech = CFGMECH_2;
478 		devmax = 16;
479 
480 		outb(CONF2_ENABLE_PORT, CONF2_ENABLE_CHK);
481 		mode2res = inb(CONF2_ENABLE_PORT);
482 		outb(CONF2_ENABLE_PORT, oldval2);
483 
484 		if (bootverbose)
485 			printf("pci_open(2a):\tmode2res=0x%02x (0x%02x)\n",
486 			    mode2res, CONF2_ENABLE_CHK);
487 
488 		if (mode2res == CONF2_ENABLE_RES) {
489 			if (bootverbose)
490 				printf("pci_open(2a):\tnow trying mechanism 2\n");
491 
492 			if (pci_cfgcheck(16))
493 				return (cfgmech);
494 		}
495 	}
496 
497 	/* Nothing worked, so punt. */
498 	cfgmech = CFGMECH_NONE;
499 	devmax = 0;
500 	return (cfgmech);
501 }
502 
503 int
504 pcie_cfgregopen(uint64_t base, uint8_t minbus, uint8_t maxbus)
505 {
506 	struct pcie_cfg_list *pcielist;
507 	struct pcie_cfg_elem *pcie_array, *elem;
508 #ifdef SMP
509 	struct pcpu *pc;
510 #endif
511 	vm_offset_t va;
512 	int i;
513 
514 	if (minbus != 0)
515 		return (0);
516 
517 #ifndef PAE
518 	if (base >= 0x100000000) {
519 		if (bootverbose)
520 			printf(
521 	    "PCI: Memory Mapped PCI configuration area base 0x%jx too high\n",
522 			    (uintmax_t)base);
523 		return (0);
524 	}
525 #endif
526 
527 	if (bootverbose)
528 		printf("PCIe: Memory Mapped configuration base @ 0x%jx\n",
529 		    (uintmax_t)base);
530 
531 #ifdef SMP
532 	SLIST_FOREACH(pc, &cpuhead, pc_allcpu)
533 #endif
534 	{
535 
536 		pcie_array = malloc(sizeof(struct pcie_cfg_elem) * PCIE_CACHE,
537 		    M_DEVBUF, M_NOWAIT);
538 		if (pcie_array == NULL)
539 			return (0);
540 
541 		va = kmem_alloc_nofault(kernel_map, PCIE_CACHE * PAGE_SIZE);
542 		if (va == 0) {
543 			free(pcie_array, M_DEVBUF);
544 			return (0);
545 		}
546 
547 #ifdef SMP
548 		pcielist = &pcie_list[pc->pc_cpuid];
549 #else
550 		pcielist = &pcie_list[0];
551 #endif
552 		TAILQ_INIT(pcielist);
553 		for (i = 0; i < PCIE_CACHE; i++) {
554 			elem = &pcie_array[i];
555 			elem->vapage = va + (i * PAGE_SIZE);
556 			elem->papage = 0;
557 			TAILQ_INSERT_HEAD(pcielist, elem, elem);
558 		}
559 	}
560 
561 	pcie_base = base;
562 	pcie_minbus = minbus;
563 	pcie_maxbus = maxbus;
564 	cfgmech = CFGMECH_PCIE;
565 	devmax = 32;
566 	return (1);
567 }
568 #endif /* !XEN */
569 
570 #define PCIE_PADDR(bar, reg, bus, slot, func)	\
571 	((bar)				|	\
572 	(((bus) & 0xff) << 20)		|	\
573 	(((slot) & 0x1f) << 15)		|	\
574 	(((func) & 0x7) << 12)		|	\
575 	((reg) & 0xfff))
576 
577 /*
578  * Find an element in the cache that matches the physical page desired, or
579  * create a new mapping from the least recently used element.
580  * A very simple LRU algorithm is used here, does it need to be more
581  * efficient?
582  */
583 static __inline struct pcie_cfg_elem *
584 pciereg_findelem(vm_paddr_t papage)
585 {
586 	struct pcie_cfg_list *pcielist;
587 	struct pcie_cfg_elem *elem;
588 
589 	pcielist = &pcie_list[PCPU_GET(cpuid)];
590 	TAILQ_FOREACH(elem, pcielist, elem) {
591 		if (elem->papage == papage)
592 			break;
593 	}
594 
595 	if (elem == NULL) {
596 		elem = TAILQ_LAST(pcielist, pcie_cfg_list);
597 		if (elem->papage != 0) {
598 			pmap_kremove(elem->vapage);
599 			invlpg(elem->vapage);
600 		}
601 		pmap_kenter(elem->vapage, papage);
602 		elem->papage = papage;
603 	}
604 
605 	if (elem != TAILQ_FIRST(pcielist)) {
606 		TAILQ_REMOVE(pcielist, elem, elem);
607 		TAILQ_INSERT_HEAD(pcielist, elem, elem);
608 	}
609 	return (elem);
610 }
611 
612 static int
613 pciereg_cfgread(int bus, unsigned slot, unsigned func, unsigned reg,
614     unsigned bytes)
615 {
616 	struct pcie_cfg_elem *elem;
617 	volatile vm_offset_t va;
618 	vm_paddr_t pa, papage;
619 	int data = -1;
620 
621 	if (bus < pcie_minbus || bus > pcie_maxbus || slot >= 32 ||
622 	    func > PCI_FUNCMAX || reg >= 0x1000 || bytes > 4 || bytes == 3)
623 		return (-1);
624 
625 	critical_enter();
626 	pa = PCIE_PADDR(pcie_base, reg, bus, slot, func);
627 	papage = pa & ~PAGE_MASK;
628 	elem = pciereg_findelem(papage);
629 	va = elem->vapage | (pa & PAGE_MASK);
630 
631 	switch (bytes) {
632 	case 4:
633 		data = *(volatile uint32_t *)(va);
634 		break;
635 	case 2:
636 		data = *(volatile uint16_t *)(va);
637 		break;
638 	case 1:
639 		data = *(volatile uint8_t *)(va);
640 		break;
641 	}
642 
643 	critical_exit();
644 	return (data);
645 }
646 
647 static void
648 pciereg_cfgwrite(int bus, unsigned slot, unsigned func, unsigned reg, int data,
649     unsigned bytes)
650 {
651 	struct pcie_cfg_elem *elem;
652 	volatile vm_offset_t va;
653 	vm_paddr_t pa, papage;
654 
655 	if (bus < pcie_minbus || bus > pcie_maxbus || slot >= 32 ||
656 	    func > PCI_FUNCMAX || reg >= 0x1000)
657 		return;
658 
659 	critical_enter();
660 	pa = PCIE_PADDR(pcie_base, reg, bus, slot, func);
661 	papage = pa & ~PAGE_MASK;
662 	elem = pciereg_findelem(papage);
663 	va = elem->vapage | (pa & PAGE_MASK);
664 
665 	switch (bytes) {
666 	case 4:
667 		*(volatile uint32_t *)(va) = data;
668 		break;
669 	case 2:
670 		*(volatile uint16_t *)(va) = data;
671 		break;
672 	case 1:
673 		*(volatile uint8_t *)(va) = data;
674 		break;
675 	}
676 
677 	critical_exit();
678 }
679