1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 1997, Stefan Esser <se@freebsd.org> 5 * Copyright (c) 2000, Michael Smith <msmith@freebsd.org> 6 * Copyright (c) 2000, BSDi 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice unmodified, this list of conditions, and the following 14 * disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/bus.h> 34 #include <sys/lock.h> 35 #include <sys/kernel.h> 36 #include <sys/malloc.h> 37 #include <sys/mutex.h> 38 #include <sys/sysctl.h> 39 #include <dev/pci/pcivar.h> 40 #include <dev/pci/pcireg.h> 41 #include <vm/vm.h> 42 #include <vm/pmap.h> 43 #include <machine/pci_cfgreg.h> 44 45 struct pcie_mcfg_region { 46 char *base; 47 uint16_t domain; 48 uint8_t minbus; 49 uint8_t maxbus; 50 }; 51 52 static uint32_t pci_docfgregread(int domain, int bus, int slot, int func, 53 int reg, int bytes); 54 static struct pcie_mcfg_region *pcie_lookup_region(int domain, int bus); 55 static int pciereg_cfgread(struct pcie_mcfg_region *region, int bus, 56 unsigned slot, unsigned func, unsigned reg, unsigned bytes); 57 static void pciereg_cfgwrite(struct pcie_mcfg_region *region, int bus, 58 unsigned slot, unsigned func, unsigned reg, int data, 59 unsigned bytes); 60 static int pcireg_cfgread(int bus, int slot, int func, int reg, int bytes); 61 static void pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes); 62 63 SYSCTL_DECL(_hw_pci); 64 65 /* 66 * For amd64 we assume that type 1 I/O port-based access always works. 67 * If an ACPI MCFG table exists, pcie_cfgregopen() will be called to 68 * switch to memory-mapped access. 69 */ 70 int cfgmech = CFGMECH_1; 71 72 static struct pcie_mcfg_region *mcfg_regions; 73 static int mcfg_numregions; 74 static uint32_t pcie_badslots; 75 static struct mtx pcicfg_mtx; 76 MTX_SYSINIT(pcicfg_mtx, &pcicfg_mtx, "pcicfg_mtx", MTX_SPIN); 77 78 static int mcfg_enable = 1; 79 SYSCTL_INT(_hw_pci, OID_AUTO, mcfg, CTLFLAG_RDTUN, &mcfg_enable, 0, 80 "Enable support for PCI-e memory mapped config access"); 81 82 int 83 pci_cfgregopen(void) 84 { 85 86 return (1); 87 } 88 89 static struct pcie_mcfg_region * 90 pcie_lookup_region(int domain, int bus) 91 { 92 for (int i = 0; i < mcfg_numregions; i++) 93 if (mcfg_regions[i].domain == domain && 94 bus >= mcfg_regions[i].minbus && 95 bus <= mcfg_regions[i].maxbus) 96 return (&mcfg_regions[i]); 97 return (NULL); 98 } 99 100 static uint32_t 101 pci_docfgregread(int domain, int bus, int slot, int func, int reg, int bytes) 102 { 103 if (domain == 0 && bus == 0 && (1 << slot & pcie_badslots) != 0) 104 return (pcireg_cfgread(bus, slot, func, reg, bytes)); 105 106 if (cfgmech == CFGMECH_PCIE) { 107 struct pcie_mcfg_region *region; 108 109 region = pcie_lookup_region(domain, bus); 110 if (region != NULL) 111 return (pciereg_cfgread(region, bus, slot, func, reg, 112 bytes)); 113 } 114 115 if (domain == 0) 116 return (pcireg_cfgread(bus, slot, func, reg, bytes)); 117 else 118 return (-1); 119 } 120 121 /* 122 * Read configuration space register 123 */ 124 u_int32_t 125 pci_cfgregread(int domain, int bus, int slot, int func, int reg, int bytes) 126 { 127 uint32_t line; 128 129 /* 130 * Some BIOS writers seem to want to ignore the spec and put 131 * 0 in the intline rather than 255 to indicate none. Some use 132 * numbers in the range 128-254 to indicate something strange and 133 * apparently undocumented anywhere. Assume these are completely bogus 134 * and map them to 255, which the rest of the PCI code recognizes as 135 * as an invalid IRQ. 136 */ 137 if (reg == PCIR_INTLINE && bytes == 1) { 138 line = pci_docfgregread(domain, bus, slot, func, PCIR_INTLINE, 139 1); 140 if (line == 0 || line >= 128) 141 line = PCI_INVALID_IRQ; 142 return (line); 143 } 144 return (pci_docfgregread(domain, bus, slot, func, reg, bytes)); 145 } 146 147 /* 148 * Write configuration space register 149 */ 150 void 151 pci_cfgregwrite(int domain, int bus, int slot, int func, int reg, uint32_t data, 152 int bytes) 153 { 154 if (domain == 0 && bus == 0 && (1 << slot & pcie_badslots) != 0) { 155 pcireg_cfgwrite(bus, slot, func, reg, data, bytes); 156 return; 157 } 158 159 if (cfgmech == CFGMECH_PCIE) { 160 struct pcie_mcfg_region *region; 161 162 region = pcie_lookup_region(domain, bus); 163 if (region != NULL) { 164 pciereg_cfgwrite(region, bus, slot, func, reg, data, 165 bytes); 166 return; 167 } 168 } 169 170 if (domain == 0) 171 pcireg_cfgwrite(bus, slot, func, reg, data, bytes); 172 } 173 174 /* 175 * Configuration space access using direct register operations 176 */ 177 178 /* enable configuration space accesses and return data port address */ 179 static int 180 pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes) 181 { 182 int dataport = 0; 183 184 if (bus <= PCI_BUSMAX && slot <= PCI_SLOTMAX && func <= PCI_FUNCMAX && 185 (unsigned)reg <= PCI_REGMAX && bytes != 3 && 186 (unsigned)bytes <= 4 && (reg & (bytes - 1)) == 0) { 187 outl(CONF1_ADDR_PORT, (1U << 31) | (bus << 16) | (slot << 11) 188 | (func << 8) | (reg & ~0x03)); 189 dataport = CONF1_DATA_PORT + (reg & 0x03); 190 } 191 return (dataport); 192 } 193 194 /* disable configuration space accesses */ 195 static void 196 pci_cfgdisable(void) 197 { 198 199 /* 200 * Do nothing. Writing a 0 to the address port can apparently 201 * confuse some bridges and cause spurious access failures. 202 */ 203 } 204 205 static int 206 pcireg_cfgread(int bus, int slot, int func, int reg, int bytes) 207 { 208 int data = -1; 209 int port; 210 211 mtx_lock_spin(&pcicfg_mtx); 212 port = pci_cfgenable(bus, slot, func, reg, bytes); 213 if (port != 0) { 214 switch (bytes) { 215 case 1: 216 data = inb(port); 217 break; 218 case 2: 219 data = inw(port); 220 break; 221 case 4: 222 data = inl(port); 223 break; 224 } 225 pci_cfgdisable(); 226 } 227 mtx_unlock_spin(&pcicfg_mtx); 228 return (data); 229 } 230 231 static void 232 pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes) 233 { 234 int port; 235 236 mtx_lock_spin(&pcicfg_mtx); 237 port = pci_cfgenable(bus, slot, func, reg, bytes); 238 if (port != 0) { 239 switch (bytes) { 240 case 1: 241 outb(port, data); 242 break; 243 case 2: 244 outw(port, data); 245 break; 246 case 4: 247 outl(port, data); 248 break; 249 } 250 pci_cfgdisable(); 251 } 252 mtx_unlock_spin(&pcicfg_mtx); 253 } 254 255 static void 256 pcie_init_badslots(struct pcie_mcfg_region *region) 257 { 258 uint32_t val1, val2; 259 int slot; 260 261 /* 262 * On some AMD systems, some of the devices on bus 0 are 263 * inaccessible using memory-mapped PCI config access. Walk 264 * bus 0 looking for such devices. For these devices, we will 265 * fall back to using type 1 config access instead. 266 */ 267 if (pci_cfgregopen() != 0) { 268 for (slot = 0; slot <= PCI_SLOTMAX; slot++) { 269 val1 = pcireg_cfgread(0, slot, 0, 0, 4); 270 if (val1 == 0xffffffff) 271 continue; 272 273 val2 = pciereg_cfgread(region, 0, slot, 0, 0, 4); 274 if (val2 != val1) 275 pcie_badslots |= (1 << slot); 276 } 277 } 278 } 279 280 int 281 pcie_cfgregopen(uint64_t base, uint16_t domain, uint8_t minbus, uint8_t maxbus) 282 { 283 struct pcie_mcfg_region *region; 284 285 if (!mcfg_enable) 286 return (0); 287 288 if (bootverbose) 289 printf("PCI: MCFG domain %u bus %u-%u base @ 0x%lx\n", 290 domain, minbus, maxbus, base); 291 292 /* Resize the array. */ 293 mcfg_regions = realloc(mcfg_regions, 294 sizeof(*mcfg_regions) * (mcfg_numregions + 1), M_DEVBUF, M_WAITOK); 295 296 region = &mcfg_regions[mcfg_numregions]; 297 298 /* XXX: We should make sure this really fits into the direct map. */ 299 region->base = pmap_mapdev_pciecfg(base, (maxbus + 1 - minbus) << 20); 300 region->domain = domain; 301 region->minbus = minbus; 302 region->maxbus = maxbus; 303 mcfg_numregions++; 304 305 cfgmech = CFGMECH_PCIE; 306 307 if (domain == 0 && minbus == 0) 308 pcie_init_badslots(region); 309 310 return (1); 311 } 312 313 #define PCIE_VADDR(base, reg, bus, slot, func) \ 314 ((base) + \ 315 ((((bus) & 0xff) << 20) | \ 316 (((slot) & 0x1f) << 15) | \ 317 (((func) & 0x7) << 12) | \ 318 ((reg) & 0xfff))) 319 320 /* 321 * AMD BIOS And Kernel Developer's Guides for CPU families starting with 10h 322 * have a requirement that all accesses to the memory mapped PCI configuration 323 * space are done using AX class of registers. 324 * Since other vendors do not currently have any contradicting requirements 325 * the AMD access pattern is applied universally. 326 */ 327 328 static int 329 pciereg_cfgread(struct pcie_mcfg_region *region, int bus, unsigned slot, 330 unsigned func, unsigned reg, unsigned bytes) 331 { 332 char *va; 333 int data = -1; 334 335 MPASS(bus >= region->minbus && bus <= region->maxbus); 336 337 if (slot > PCI_SLOTMAX || func > PCI_FUNCMAX || reg > PCIE_REGMAX) 338 return (-1); 339 340 va = PCIE_VADDR(region->base, reg, bus - region->minbus, slot, func); 341 342 switch (bytes) { 343 case 4: 344 __asm("movl %1, %0" : "=a" (data) 345 : "m" (*(volatile uint32_t *)va)); 346 break; 347 case 2: 348 __asm("movzwl %1, %0" : "=a" (data) 349 : "m" (*(volatile uint16_t *)va)); 350 break; 351 case 1: 352 __asm("movzbl %1, %0" : "=a" (data) 353 : "m" (*(volatile uint8_t *)va)); 354 break; 355 } 356 357 return (data); 358 } 359 360 static void 361 pciereg_cfgwrite(struct pcie_mcfg_region *region, int bus, unsigned slot, 362 unsigned func, unsigned reg, int data, unsigned bytes) 363 { 364 char *va; 365 366 MPASS(bus >= region->minbus && bus <= region->maxbus); 367 368 if (slot > PCI_SLOTMAX || func > PCI_FUNCMAX || reg > PCIE_REGMAX) 369 return; 370 371 va = PCIE_VADDR(region->base, reg, bus - region->minbus, slot, func); 372 373 switch (bytes) { 374 case 4: 375 __asm("movl %1, %0" : "=m" (*(volatile uint32_t *)va) 376 : "a" (data)); 377 break; 378 case 2: 379 __asm("movw %1, %0" : "=m" (*(volatile uint16_t *)va) 380 : "a" ((uint16_t)data)); 381 break; 382 case 1: 383 __asm("movb %1, %0" : "=m" (*(volatile uint8_t *)va) 384 : "a" ((uint8_t)data)); 385 break; 386 } 387 } 388