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pcibios.c revision 1.37.2.1
      1 /*	$NetBSD: pcibios.c,v 1.37.2.1 2010/05/30 05:16:54 rmind Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1999 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
      9  * NASA Ames Research Center.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     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.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     30  * POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 /*
     34  * Copyright (c) 1999, by UCHIYAMA Yasushi
     35  * All rights reserved.
     36  *
     37  * Redistribution and use in source and binary forms, with or without
     38  * modification, are permitted provided that the following conditions
     39  * are met:
     40  * 1. Redistributions of source code must retain the above copyright
     41  *    notice, this list of conditions and the following disclaimer.
     42  * 2. The name of the developer may NOT be used to endorse or promote products
     43  *    derived from this software without specific prior written permission.
     44  *
     45  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     55  * SUCH DAMAGE.
     56  */
     57 
     58 /*
     59  * Interface to the PCI BIOS and PCI Interrupt Routing table.
     60  */
     61 
     62 #include <sys/cdefs.h>
     63 __KERNEL_RCSID(0, "$NetBSD: pcibios.c,v 1.37.2.1 2010/05/30 05:16:54 rmind Exp $");
     64 
     65 #include "opt_pcibios.h"
     66 #include "opt_pcifixup.h"
     67 
     68 #include <sys/param.h>
     69 #include <sys/systm.h>
     70 #include <sys/device.h>
     71 #include <sys/malloc.h>
     72 
     73 #include <dev/isa/isareg.h>
     74 #include <machine/isa_machdep.h>
     75 
     76 #include <dev/pci/pcireg.h>
     77 #include <dev/pci/pcivar.h>
     78 #include <dev/pci/pcidevs.h>
     79 
     80 #include <i386/pci/pcibios.h>
     81 
     82 #if 	defined(PCIBIOS_INTR_FIXUP) || defined(PCIBIOS_ADDR_FIXUP) || \
     83 	defined(PCIBIOS_BUS_FIXUP)
     84 #error The options PCIBIOS_INTR_FIXUP, PCIBIOS_ADDR_FIXUP, and PCIBIOS_BUS_FIXUP have been obsoleted by PCI_INTR_FIXUP, PCI_ADDR_FIXUP, and PCI_BUS_FIXUP.  Please adjust your kernel configuration file.
     85 #endif
     86 
     87 #ifdef PCI_INTR_FIXUP
     88 #include <i386/pci/pci_intr_fixup.h>
     89 #endif
     90 
     91 #include <machine/bios32.h>
     92 
     93 #ifdef PCIBIOSVERBOSE
     94 int	pcibiosverbose = 1;
     95 #endif
     96 
     97 int pcibios_present;
     98 
     99 struct pcibios_pir_header pcibios_pir_header;
    100 struct pcibios_intr_routing *pcibios_pir_table;
    101 int pcibios_pir_table_nentries;
    102 int pcibios_max_bus;
    103 
    104 struct bios32_entry pcibios_entry;
    105 
    106 void	pcibios_pir_init(void);
    107 
    108 int	pcibios_get_status(uint32_t *, uint32_t *, uint32_t *,
    109 	    uint32_t *, uint32_t *, uint32_t *, uint32_t *);
    110 int	pcibios_get_intr_routing(struct pcibios_intr_routing *,
    111 	    int *, uint16_t *);
    112 
    113 int	pcibios_return_code(uint16_t, const char *);
    114 
    115 void	pcibios_print_exclirq(void);
    116 
    117 #ifdef PCIBIOS_LIBRETTO_FIXUP
    118 /* for Libretto L2/L3 hack */
    119 static void	pcibios_fixup_pir_table(void);
    120 static void	pcibios_fixup_pir_table_mask(struct pcibios_linkmap *);
    121 
    122 struct pcibios_linkmap pir_mask[] = {
    123 	{ 2,	0x0040 },
    124 	{ 7,	0x0080 },
    125 	{ 8,	0x0020 },
    126 	{ 0,	0x0000 }
    127 };
    128 #endif
    129 
    130 #ifdef PCIBIOS_SHARP_MM20_FIXUP
    131 static void pcibios_mm20_fixup(void);
    132 #endif
    133 
    134 #ifdef PCIINTR_DEBUG
    135 void	pcibios_print_pir_table(void);
    136 #endif
    137 
    138 #define	PCI_IRQ_TABLE_START	0xf0000
    139 #define	PCI_IRQ_TABLE_END	0xfffff
    140 
    141 void
    142 pcibios_init(void)
    143 {
    144 	struct bios32_entry_info ei;
    145 	uint32_t rev_maj, rev_min, mech1, mech2, scmech1, scmech2;
    146 
    147 	if (bios32_service(BIOS32_MAKESIG('$', 'P', 'C', 'I'),
    148 	    &pcibios_entry, &ei) == 0) {
    149 		/*
    150 		 * No PCI BIOS found; will fall back on old
    151 		 * mechanism.
    152 		 */
    153 		return;
    154 	}
    155 
    156 	/*
    157 	 * We've located the PCI BIOS service; get some information
    158 	 * about it.
    159 	 */
    160 	if (pcibios_get_status(&rev_maj, &rev_min, &mech1, &mech2,
    161 	    &scmech1, &scmech2, &pcibios_max_bus) != PCIBIOS_SUCCESS) {
    162 		/*
    163 		 * We can't use the PCI BIOS; will fall back on old
    164 		 * mechanism.
    165 		 */
    166 		return;
    167 	}
    168 
    169 	aprint_normal("PCI BIOS rev. %d.%d found at 0x%lx\n",
    170 	    rev_maj, rev_min >> 4, ei.bei_entry);
    171 	aprint_verbose("pcibios: config mechanism %s%s, special cycles %s%s, "
    172 	    "last bus %d\n",
    173 	    mech1 ? "[1]" : "[x]",
    174 	    mech2 ? "[2]" : "[x]",
    175 	    scmech1 ? "[1]" : "[x]",
    176 	    scmech2 ? "[2]" : "[x]",
    177 	    pcibios_max_bus);
    178 
    179 	/*
    180 	 * The PCI BIOS tells us the config mechanism; fill it in now
    181 	 * so that pci_mode_detect() doesn't have to look for it.
    182 	 */
    183 	pci_mode_set(mech1 ? 1 : 2);
    184 
    185 	pcibios_present = 1;
    186 
    187 	/*
    188 	 * Find the PCI IRQ Routing table.
    189 	 */
    190 	pcibios_pir_init();
    191 
    192 #ifdef PCI_INTR_FIXUP
    193 	if (pcibios_pir_table != NULL) {
    194 		int rv;
    195 		uint16_t pciirq;
    196 
    197 		/*
    198 		 * Fixup interrupt routing.
    199 		 */
    200 		rv = pci_intr_fixup(NULL, x86_bus_space_io, &pciirq);
    201 		switch (rv) {
    202 		case -1:
    203 			/* Non-fatal error. */
    204 			aprint_error("Warning: unable to fix up PCI interrupt "
    205 			    "routing\n");
    206 			break;
    207 
    208 		case 1:
    209 			/* Fatal error. */
    210 			panic("pcibios_init: interrupt fixup failed");
    211 			break;
    212 		}
    213 
    214 		/*
    215 		 * XXX Clear `pciirq' from the ISA interrupt allocation
    216 		 * XXX mask.
    217 		 */
    218 	}
    219 #endif
    220 }
    221 
    222 void
    223 pcibios_pir_init(void)
    224 {
    225 	char *devinfo;
    226 	paddr_t pa;
    227 	char *p;
    228 	unsigned char cksum;
    229 	uint16_t tablesize;
    230 	uint8_t rev_maj, rev_min;
    231 	int i;
    232 
    233 	for (pa = PCI_IRQ_TABLE_START; pa < PCI_IRQ_TABLE_END; pa += 16) {
    234 		p = (void *)ISA_HOLE_VADDR(pa);
    235 		if (*(int *)p != BIOS32_MAKESIG('$', 'P', 'I', 'R')) {
    236 			/*
    237 			 * XXX: Some laptops (Toshiba/Libretto L series)
    238 			 * use _PIR instead of $PIR. So we try that too.
    239 			 */
    240 			if (*(int *)p != BIOS32_MAKESIG('_', 'P', 'I', 'R'))
    241 				continue;
    242 		}
    243 
    244 		rev_min = *(p + 4);
    245 		rev_maj = *(p + 5);
    246 		tablesize = *(uint16_t *)(p + 6);
    247 
    248 		cksum = 0;
    249 		for (i = 0; i < tablesize; i++)
    250 			cksum += *(unsigned char *)(p + i);
    251 
    252 		aprint_normal(
    253 		    "PCI IRQ Routing Table rev. %d.%d found at 0x%lx, "
    254 		    "size %d bytes (%d entries)\n", rev_maj, rev_min, pa,
    255 		    tablesize, (tablesize - 32) / 16);
    256 
    257 		if (cksum != 0) {
    258 			aprint_error("pcibios_pir_init: bad IRQ table checksum\n");
    259 			continue;
    260 		}
    261 
    262 		if (tablesize < 32 || (tablesize % 16) != 0) {
    263 			aprint_error("pcibios_pir_init: bad IRQ table size\n");
    264 			continue;
    265 		}
    266 
    267 		if (rev_maj != 1 || rev_min != 0) {
    268 			aprint_error("pcibios_pir_init: unsupported IRQ table "
    269 			    "version\n");
    270 			continue;
    271 		}
    272 
    273 		/*
    274 		 * We can handle this table!  Make a copy of it.
    275 		 */
    276 		memcpy(&pcibios_pir_header, p, 32);
    277 		pcibios_pir_table = malloc(tablesize - 32, M_DEVBUF,
    278 		    M_NOWAIT);
    279 		if (pcibios_pir_table == NULL) {
    280 			aprint_error("pcibios_pir_init: no memory for $PIR\n");
    281 			return;
    282 		}
    283 		memcpy(pcibios_pir_table, p + 32, tablesize - 32);
    284 		pcibios_pir_table_nentries = (tablesize - 32) / 16;
    285 
    286 		aprint_verbose("PCI Interrupt Router at %03d:%02d:%01d",
    287 		    pcibios_pir_header.router_bus,
    288 		    PIR_DEVFUNC_DEVICE(pcibios_pir_header.router_devfunc),
    289 		    PIR_DEVFUNC_FUNCTION(pcibios_pir_header.router_devfunc));
    290 		if (pcibios_pir_header.compat_router != 0) {
    291 			devinfo = malloc(256, M_DEVBUF, M_NOWAIT);
    292 			if (devinfo) {
    293 				pci_devinfo(pcibios_pir_header.compat_router,
    294 				    0, 0, devinfo, 256);
    295 				aprint_verbose(" (%s compatible)", devinfo);
    296 				free(devinfo, M_DEVBUF);
    297 			}
    298 		}
    299 		aprint_verbose("\n");
    300 		pcibios_print_exclirq();
    301 
    302 #ifdef PCIBIOS_LIBRETTO_FIXUP
    303 		/* for Libretto L2/L3 hack */
    304 		pcibios_fixup_pir_table();
    305 #endif
    306 #ifdef PCIBIOS_SHARP_MM20_FIXUP
    307 		pcibios_mm20_fixup();
    308 #endif
    309 #ifdef PCIINTR_DEBUG
    310 		pcibios_print_pir_table();
    311 #endif
    312 		return;
    313 	}
    314 
    315 	/*
    316 	 * If there was no PIR table found, try using the PCI BIOS
    317 	 * Get Interrupt Routing call.
    318 	 *
    319 	 * XXX The interface to this call sucks; just allocate enough
    320 	 * XXX room for 32 entries.
    321 	 */
    322 	pcibios_pir_table_nentries = 32;
    323 	pcibios_pir_table = malloc(pcibios_pir_table_nentries *
    324 	    sizeof(*pcibios_pir_table), M_DEVBUF, M_NOWAIT);
    325 	if (pcibios_pir_table == NULL) {
    326 		aprint_error("pcibios_pir_init: no memory for $PIR\n");
    327 		return;
    328 	}
    329 	if (pcibios_get_intr_routing(pcibios_pir_table,
    330 	    &pcibios_pir_table_nentries,
    331 	    &pcibios_pir_header.exclusive_irq) != PCIBIOS_SUCCESS) {
    332 		aprint_normal("No PCI IRQ Routing information available.\n");
    333 		free(pcibios_pir_table, M_DEVBUF);
    334 		pcibios_pir_table = NULL;
    335 		pcibios_pir_table_nentries = 0;
    336 		return;
    337 	}
    338 	aprint_verbose("PCI BIOS has %d Interrupt Routing table entries\n",
    339 	    pcibios_pir_table_nentries);
    340 	pcibios_print_exclirq();
    341 
    342 #ifdef PCIBIOS_LIBRETTO_FIXUP
    343 	/* for Libretto L2/L3 hack */
    344 	pcibios_fixup_pir_table();
    345 #endif
    346 #ifdef PCIBIOS_SHARP_MM20_FIXUP
    347 	pcibios_mm20_fixup();
    348 #endif
    349 #ifdef PCIINTR_DEBUG
    350 	pcibios_print_pir_table();
    351 #endif
    352 }
    353 
    354 int
    355 pcibios_get_status(uint32_t *rev_maj, uint32_t *rev_min,
    356     uint32_t *mech1, uint32_t *mech2, uint32_t *scmech1, uint32_t *scmech2,
    357     uint32_t *maxbus)
    358 {
    359 	uint16_t ax, bx, cx;
    360 	uint32_t edx;
    361 	int rv;
    362 
    363 	__asm volatile("lcall *(%%edi)				; \
    364 			jc 1f						; \
    365 			xor %%ah, %%ah					; \
    366 		1:"
    367 		: "=a" (ax), "=b" (bx), "=c" (cx), "=d" (edx)
    368 		: "0" (0xb101), "D" (&pcibios_entry));
    369 
    370 	rv = pcibios_return_code(ax, "pcibios_get_status");
    371 	if (rv != PCIBIOS_SUCCESS)
    372 		return (rv);
    373 
    374 	if (edx != BIOS32_MAKESIG('P', 'C', 'I', ' '))
    375 		return (PCIBIOS_SERVICE_NOT_PRESENT);	/* XXX */
    376 
    377 	/*
    378 	 * Fill in the various pieces if info we're looking for.
    379 	 */
    380 	*mech1 = ax & 1;
    381 	*mech2 = ax & (1 << 1);
    382 	*scmech1 = ax & (1 << 4);
    383 	*scmech2 = ax & (1 << 5);
    384 	*rev_maj = (bx >> 8) & 0xff;
    385 	*rev_min = bx & 0xff;
    386 	*maxbus = cx & 0xff;
    387 
    388 	return (PCIBIOS_SUCCESS);
    389 }
    390 
    391 int
    392 pcibios_get_intr_routing(struct pcibios_intr_routing *table,
    393     int *nentries, uint16_t *exclirq)
    394 {
    395 	uint16_t ax, bx;
    396 	int rv;
    397 	struct {
    398 		uint16_t size;
    399 		void *offset;
    400 		uint16_t segment;
    401 	} __packed args;
    402 
    403 	args.size = *nentries * sizeof(*table);
    404 	args.offset = (void *)table;
    405 	args.segment = GSEL(GDATA_SEL, SEL_KPL);
    406 
    407 	memset(table, 0, args.size);
    408 
    409 	__asm volatile("lcall *(%%esi)				; \
    410 			jc 1f						; \
    411 			xor %%ah, %%ah					; \
    412 		1:	movw %w2, %%ds					; \
    413 			movw %w2, %%es"
    414 		: "=a" (ax), "=b" (bx)
    415 		: "r" GSEL(GDATA_SEL, SEL_KPL), "0" (0xb10e), "1" (0),
    416 		  "D" (&args), "S" (&pcibios_entry));
    417 
    418 	rv = pcibios_return_code(ax, "pcibios_get_intr_routing");
    419 	if (rv != PCIBIOS_SUCCESS)
    420 		return (rv);
    421 
    422 	*nentries = args.size / sizeof(*table);
    423 	*exclirq = bx;
    424 
    425 	return (PCIBIOS_SUCCESS);
    426 }
    427 
    428 int
    429 pcibios_return_code(uint16_t ax, const char *func)
    430 {
    431 	const char *errstr;
    432 	int rv = ax >> 8;
    433 
    434 	switch (rv) {
    435 	case PCIBIOS_SUCCESS:
    436 		return (PCIBIOS_SUCCESS);
    437 
    438 	case PCIBIOS_SERVICE_NOT_PRESENT:
    439 		errstr = "service not present";
    440 		break;
    441 
    442 	case PCIBIOS_FUNCTION_NOT_SUPPORTED:
    443 		errstr = "function not supported";
    444 		break;
    445 
    446 	case PCIBIOS_BAD_VENDOR_ID:
    447 		errstr = "bad vendor ID";
    448 		break;
    449 
    450 	case PCIBIOS_DEVICE_NOT_FOUND:
    451 		errstr = "device not found";
    452 		break;
    453 
    454 	case PCIBIOS_BAD_REGISTER_NUMBER:
    455 		errstr = "bad register number";
    456 		break;
    457 
    458 	case PCIBIOS_SET_FAILED:
    459 		errstr = "set failed";
    460 		break;
    461 
    462 	case PCIBIOS_BUFFER_TOO_SMALL:
    463 		errstr = "buffer too small";
    464 		break;
    465 
    466 	default:
    467 		aprint_error("%s: unknown return code 0x%x\n", func, rv);
    468 		return (rv);
    469 	}
    470 
    471 	aprint_error("%s: %s\n", func, errstr);
    472 	return (rv);
    473 }
    474 
    475 void
    476 pcibios_print_exclirq(void)
    477 {
    478 	int i;
    479 
    480 	if (pcibios_pir_header.exclusive_irq) {
    481 		aprint_verbose("PCI Exclusive IRQs:");
    482 		for (i = 0; i < 16; i++) {
    483 			if (pcibios_pir_header.exclusive_irq & (1 << i))
    484 				aprint_verbose(" %d", i);
    485 		}
    486 		aprint_verbose("\n");
    487 	}
    488 }
    489 
    490 #ifdef PCIBIOS_LIBRETTO_FIXUP
    491 /* for Libretto L2/L3 hack */
    492 static void
    493 pcibios_fixup_pir_table(void)
    494 {
    495 	struct pcibios_linkmap *m;
    496 
    497 	for (m = pir_mask; m->link != 0; m++)
    498 		pcibios_fixup_pir_table_mask(m);
    499 }
    500 
    501 void
    502 pcibios_fixup_pir_table_mask(struct pcibios_linkmap *mask)
    503 {
    504 	int i, j;
    505 
    506 	for (i = 0; i < pcibios_pir_table_nentries; i++) {
    507 		for (j = 0; j < 4; j++) {
    508 			if (pcibios_pir_table[i].linkmap[j].link == mask->link) {
    509 				pcibios_pir_table[i].linkmap[j].bitmap
    510 				    &= mask->bitmap;
    511 			}
    512 		}
    513 	}
    514 }
    515 #endif
    516 
    517 #ifdef PCIINTR_DEBUG
    518 void
    519 pcibios_print_pir_table(void)
    520 {
    521 	int i, j;
    522 
    523 	for (i = 0; i < pcibios_pir_table_nentries; i++) {
    524 		printf("PIR Entry %d:\n", i);
    525 		printf("\tBus: %d  Device: %d\n",
    526 		    pcibios_pir_table[i].bus,
    527 		    PIR_DEVFUNC_DEVICE(pcibios_pir_table[i].device));
    528 		for (j = 0; j < 4; j++) {
    529 			printf("\t\tINT%c: link 0x%02x bitmap 0x%04x\n",
    530 			    'A' + j,
    531 			    pcibios_pir_table[i].linkmap[j].link,
    532 			    pcibios_pir_table[i].linkmap[j].bitmap);
    533 		}
    534 	}
    535 }
    536 #endif
    537 
    538 #ifdef PCIBIOS_SHARP_MM20_FIXUP
    539 /*
    540  * This is a gross hack to get the interrupt from the EHCI controller
    541  * working on a Sharp MM20.  The BIOS is just incredibly buggy.
    542  *
    543  * The story thus far:
    544  * The modern way to route the interrupt is to use ACPI.  But using
    545  * ACPI fails with an error message about an uninitialized local
    546  * variable in the AML code.  (It works in Windows, but fails in NetBSD
    547  * and Linux.)
    548  *
    549  * The second attempt is to use PCI Interrupt Routing table.  But this
    550  * fails because the table does not contain any information about the
    551  * interrupt from the EHCI controller.  This is probably due to the fact
    552  * that the table is compatible with ALi M1543, but the MM20 has an ALi M1563.
    553  * The M1563 has additional interrupt lines.  The ali1543.c code also
    554  * cannot handle the M1653's extended interrupts.  And fixing this is
    555  * difficult since getting a data sheet from ALi requires signing an NDA.
    556  *
    557  * The third attempt is to use a BIOS call to route the interrupt
    558  * (as FreeBSD does) with manually generated information.  But the BIOS call
    559  * fails because the BIOS code is not quite position independent.  It makes
    560  * some assumption about where the code segment register points.
    561  *
    562  * So the solution is to use the third attempt, but with a patched version
    563  * of the BIOS.
    564  *    -- lennart (at) augustsson.net
    565  */
    566 
    567 #define	BIOS32_START	0xe0000
    568 #define	BIOS32_SIZE	0x20000
    569 
    570 static char pcibios_shadow[BIOS32_SIZE];
    571 static struct bios32_entry pcibios_entry_shadow;
    572 
    573 /*
    574  * Copy BIOS and zap offending instruction.
    575  * The bad instruction is
    576  *    mov    %cs:0x63c(%ebx),%ah
    577  * NetBSD does not have the code segment set up for this to work.
    578  * Using the value 0xff for the table entry seems to work.
    579  * The replacement is
    580  *    mov $0xff,%ah; nop; nop; nop; nop; nop
    581  */
    582 static void
    583 pcibios_copy_bios(void)
    584 {
    585 	uint8_t *bad_instr;
    586 
    587 	memcpy(pcibios_shadow, ISA_HOLE_VADDR(BIOS32_START), BIOS32_SIZE);
    588 	pcibios_entry_shadow = pcibios_entry;
    589 	pcibios_entry_shadow.offset =
    590 	    (void*)((u_long)pcibios_shadow +
    591 		    (u_long)pcibios_entry.offset -
    592 		    (u_long)ISA_HOLE_VADDR(BIOS32_START));
    593 
    594 	bad_instr = (uint8_t *)pcibios_entry_shadow.offset + 0x499;
    595 	if (*bad_instr != 0x2e)
    596 		panic("bad bios");
    597 	bad_instr[0] = 0xb4; bad_instr[1] = 0xff; /* mov $0xff,%ah */
    598 	bad_instr[2] = 0x90;		/* nop */
    599 	bad_instr[3] = 0x90;		/* nop */
    600 	bad_instr[4] = 0x90;		/* nop */
    601 	bad_instr[5] = 0x90;		/* nop */
    602 	bad_instr[6] = 0x90;		/* nop */
    603 }
    604 
    605 /*
    606  * Call BIOS to route an interrupt.
    607  * The PCI device is identified by bus,device,func.
    608  * The interrupt is on pin PIN (A-D) and interrupt IRQ.
    609  * BIOS knows the magic for the interrupt controller.
    610  */
    611 static int
    612 pcibios_biosroute(int bus, int device, int func, int pin, int irq)
    613 {
    614 	uint16_t ax, bx, cx;
    615 	int rv;
    616 
    617 	aprint_debug("pcibios_biosroute: b,d,f=%d,%d,%d pin=%x irq=%d\n",
    618 	       bus, device, func, pin+0xa, irq);
    619 
    620 	bx = (bus << 8) | (device << 3) | func;
    621 	cx = (irq << 8) | (0xa + pin);
    622 
    623 	__asm volatile("lcall *(%%esi)				; \
    624 			jc 1f						; \
    625 			xor %%ah, %%ah					; \
    626 		1:	movw %w1, %%ds					; \
    627 			movw %w1, %%es"
    628 			 : "=a" (ax)
    629 			 : "r" GSEL(GDATA_SEL, SEL_KPL), "0" (0xb10f),
    630 			   "b" (bx), "c" (cx),
    631 		           "S" (&pcibios_entry_shadow));
    632 
    633 	rv = pcibios_return_code(ax, "pcibios_biosroute");
    634 
    635 	return rv;
    636 }
    637 
    638 #define MM20_PCI_BUS 0
    639 #define MM20_PCI_EHCI_DEV 15
    640 #define MM20_PCI_EHCI_FUNC 3
    641 #define MM20_PCI_EHCI_PIN 3
    642 #define MM20_PCI_EHCI_INTR 11
    643 #define MM20_PCI_ISA_DEV 3
    644 #define MM20_PCI_ISA_FUNC 0
    645 
    646 static void
    647 pcibios_mm20_fixup(void)
    648 {
    649 	pci_chipset_tag_t pc;
    650 	pcitag_t tag;
    651 
    652 	/* Copy BIOS */
    653 	pcibios_copy_bios();
    654 	/* Route the interrupt for the EHCI controller. */
    655 	(void)pcibios_biosroute(MM20_PCI_BUS,
    656 				MM20_PCI_EHCI_DEV,
    657 				MM20_PCI_EHCI_FUNC,
    658 				MM20_PCI_EHCI_PIN,
    659 				MM20_PCI_EHCI_INTR);
    660 
    661 	/* Fake some tags. */
    662 	pc = NULL;
    663 	tag = pci_make_tag(pc, MM20_PCI_BUS, MM20_PCI_EHCI_DEV,
    664 			   MM20_PCI_EHCI_FUNC);
    665 	/* Set interrupt register in EHCI controller */
    666 	pci_conf_write(pc, tag, PCI_INTERRUPT_REG,
    667 	    0x50000400 + MM20_PCI_EHCI_INTR);
    668 	tag = pci_make_tag(pc, MM20_PCI_BUS, MM20_PCI_ISA_DEV,
    669 			   MM20_PCI_ISA_FUNC);
    670 	/* Set some unknown registers in the ISA bridge. */
    671 	pci_conf_write(pc, tag, 0x58, 0xd87f5300);
    672 	pci_conf_write(pc, tag, 0x74, 0x00000009);
    673 }
    674 
    675 #endif /* PCIBIOS_SHARP_MM20_FIXUP */
    676