1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/bus.h> 37 #include <sys/lock.h> 38 #include <sys/kernel.h> 39 #include <sys/mutex.h> 40 #include <sys/sysctl.h> 41 #include <dev/pci/pcivar.h> 42 #include <dev/pci/pcireg.h> 43 #include <vm/vm.h> 44 #include <vm/pmap.h> 45 #include <machine/pci_cfgreg.h> 46 47 static uint32_t pci_docfgregread(int bus, int slot, int func, int reg, 48 int bytes); 49 static int pciereg_cfgread(int bus, unsigned slot, unsigned func, 50 unsigned reg, unsigned bytes); 51 static void pciereg_cfgwrite(int bus, unsigned slot, unsigned func, 52 unsigned reg, int data, unsigned bytes); 53 static int pcireg_cfgread(int bus, int slot, int func, int reg, int bytes); 54 static void pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes); 55 56 SYSCTL_DECL(_hw_pci); 57 58 /* 59 * For amd64 we assume that type 1 I/O port-based access always works. 60 * If an ACPI MCFG table exists, pcie_cfgregopen() will be called to 61 * switch to memory-mapped access. 62 */ 63 int cfgmech = CFGMECH_1; 64 65 static vm_offset_t pcie_base; 66 static int pcie_minbus, pcie_maxbus; 67 static uint32_t pcie_badslots; 68 static struct mtx pcicfg_mtx; 69 MTX_SYSINIT(pcicfg_mtx, &pcicfg_mtx, "pcicfg_mtx", MTX_SPIN); 70 static int mcfg_enable = 1; 71 SYSCTL_INT(_hw_pci, OID_AUTO, mcfg, CTLFLAG_RDTUN, &mcfg_enable, 0, 72 "Enable support for PCI-e memory mapped config access"); 73 74 int 75 pci_cfgregopen(void) 76 { 77 78 return (1); 79 } 80 81 static uint32_t 82 pci_docfgregread(int bus, int slot, int func, int reg, int bytes) 83 { 84 85 if (cfgmech == CFGMECH_PCIE && 86 (bus >= pcie_minbus && bus <= pcie_maxbus) && 87 (bus != 0 || !(1 << slot & pcie_badslots))) 88 return (pciereg_cfgread(bus, slot, func, reg, bytes)); 89 else 90 return (pcireg_cfgread(bus, slot, func, reg, bytes)); 91 } 92 93 /* 94 * Read configuration space register 95 */ 96 u_int32_t 97 pci_cfgregread(int bus, int slot, int func, int reg, int bytes) 98 { 99 uint32_t line; 100 101 /* 102 * Some BIOS writers seem to want to ignore the spec and put 103 * 0 in the intline rather than 255 to indicate none. Some use 104 * numbers in the range 128-254 to indicate something strange and 105 * apparently undocumented anywhere. Assume these are completely bogus 106 * and map them to 255, which the rest of the PCI code recognizes as 107 * as an invalid IRQ. 108 */ 109 if (reg == PCIR_INTLINE && bytes == 1) { 110 line = pci_docfgregread(bus, slot, func, PCIR_INTLINE, 1); 111 if (line == 0 || line >= 128) 112 line = PCI_INVALID_IRQ; 113 return (line); 114 } 115 return (pci_docfgregread(bus, slot, func, reg, bytes)); 116 } 117 118 /* 119 * Write configuration space register 120 */ 121 void 122 pci_cfgregwrite(int bus, int slot, int func, int reg, u_int32_t data, int bytes) 123 { 124 125 if (cfgmech == CFGMECH_PCIE && 126 (bus >= pcie_minbus && bus <= pcie_maxbus) && 127 (bus != 0 || !(1 << slot & pcie_badslots))) 128 pciereg_cfgwrite(bus, slot, func, reg, data, bytes); 129 else 130 pcireg_cfgwrite(bus, slot, func, reg, data, bytes); 131 } 132 133 /* 134 * Configuration space access using direct register operations 135 */ 136 137 /* enable configuration space accesses and return data port address */ 138 static int 139 pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes) 140 { 141 int dataport = 0; 142 143 if (bus <= PCI_BUSMAX && slot <= PCI_SLOTMAX && func <= PCI_FUNCMAX && 144 (unsigned)reg <= PCI_REGMAX && bytes != 3 && 145 (unsigned)bytes <= 4 && (reg & (bytes - 1)) == 0) { 146 outl(CONF1_ADDR_PORT, (1U << 31) | (bus << 16) | (slot << 11) 147 | (func << 8) | (reg & ~0x03)); 148 dataport = CONF1_DATA_PORT + (reg & 0x03); 149 } 150 return (dataport); 151 } 152 153 /* disable configuration space accesses */ 154 static void 155 pci_cfgdisable(void) 156 { 157 158 /* 159 * Do nothing. Writing a 0 to the address port can apparently 160 * confuse some bridges and cause spurious access failures. 161 */ 162 } 163 164 static int 165 pcireg_cfgread(int bus, int slot, int func, int reg, int bytes) 166 { 167 int data = -1; 168 int port; 169 170 mtx_lock_spin(&pcicfg_mtx); 171 port = pci_cfgenable(bus, slot, func, reg, bytes); 172 if (port != 0) { 173 switch (bytes) { 174 case 1: 175 data = inb(port); 176 break; 177 case 2: 178 data = inw(port); 179 break; 180 case 4: 181 data = inl(port); 182 break; 183 } 184 pci_cfgdisable(); 185 } 186 mtx_unlock_spin(&pcicfg_mtx); 187 return (data); 188 } 189 190 static void 191 pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes) 192 { 193 int port; 194 195 mtx_lock_spin(&pcicfg_mtx); 196 port = pci_cfgenable(bus, slot, func, reg, bytes); 197 if (port != 0) { 198 switch (bytes) { 199 case 1: 200 outb(port, data); 201 break; 202 case 2: 203 outw(port, data); 204 break; 205 case 4: 206 outl(port, data); 207 break; 208 } 209 pci_cfgdisable(); 210 } 211 mtx_unlock_spin(&pcicfg_mtx); 212 } 213 214 int 215 pcie_cfgregopen(uint64_t base, uint8_t minbus, uint8_t maxbus) 216 { 217 uint32_t val1, val2; 218 int slot; 219 220 if (!mcfg_enable) 221 return (0); 222 223 if (minbus != 0) 224 return (0); 225 226 if (bootverbose) 227 printf("PCIe: Memory Mapped configuration base @ 0x%lx\n", 228 base); 229 230 /* XXX: We should make sure this really fits into the direct map. */ 231 pcie_base = (vm_offset_t)pmap_mapdev_pciecfg(base, (maxbus + 1) << 20); 232 pcie_minbus = minbus; 233 pcie_maxbus = maxbus; 234 cfgmech = CFGMECH_PCIE; 235 236 /* 237 * On some AMD systems, some of the devices on bus 0 are 238 * inaccessible using memory-mapped PCI config access. Walk 239 * bus 0 looking for such devices. For these devices, we will 240 * fall back to using type 1 config access instead. 241 */ 242 if (pci_cfgregopen() != 0) { 243 for (slot = 0; slot <= PCI_SLOTMAX; slot++) { 244 val1 = pcireg_cfgread(0, slot, 0, 0, 4); 245 if (val1 == 0xffffffff) 246 continue; 247 248 val2 = pciereg_cfgread(0, slot, 0, 0, 4); 249 if (val2 != val1) 250 pcie_badslots |= (1 << slot); 251 } 252 } 253 254 return (1); 255 } 256 257 #define PCIE_VADDR(base, reg, bus, slot, func) \ 258 ((base) + \ 259 ((((bus) & 0xff) << 20) | \ 260 (((slot) & 0x1f) << 15) | \ 261 (((func) & 0x7) << 12) | \ 262 ((reg) & 0xfff))) 263 264 /* 265 * AMD BIOS And Kernel Developer's Guides for CPU families starting with 10h 266 * have a requirement that all accesses to the memory mapped PCI configuration 267 * space are done using AX class of registers. 268 * Since other vendors do not currently have any contradicting requirements 269 * the AMD access pattern is applied universally. 270 */ 271 272 static int 273 pciereg_cfgread(int bus, unsigned slot, unsigned func, unsigned reg, 274 unsigned bytes) 275 { 276 vm_offset_t va; 277 int data = -1; 278 279 if (bus < pcie_minbus || bus > pcie_maxbus || slot > PCI_SLOTMAX || 280 func > PCI_FUNCMAX || reg > PCIE_REGMAX) 281 return (-1); 282 283 va = PCIE_VADDR(pcie_base, reg, bus, slot, func); 284 285 switch (bytes) { 286 case 4: 287 __asm("movl %1, %0" : "=a" (data) 288 : "m" (*(volatile uint32_t *)va)); 289 break; 290 case 2: 291 __asm("movzwl %1, %0" : "=a" (data) 292 : "m" (*(volatile uint16_t *)va)); 293 break; 294 case 1: 295 __asm("movzbl %1, %0" : "=a" (data) 296 : "m" (*(volatile uint8_t *)va)); 297 break; 298 } 299 300 return (data); 301 } 302 303 static void 304 pciereg_cfgwrite(int bus, unsigned slot, unsigned func, unsigned reg, int data, 305 unsigned bytes) 306 { 307 vm_offset_t va; 308 309 if (bus < pcie_minbus || bus > pcie_maxbus || slot > PCI_SLOTMAX || 310 func > PCI_FUNCMAX || reg > PCIE_REGMAX) 311 return; 312 313 va = PCIE_VADDR(pcie_base, reg, bus, slot, func); 314 315 switch (bytes) { 316 case 4: 317 __asm("movl %1, %0" : "=m" (*(volatile uint32_t *)va) 318 : "a" (data)); 319 break; 320 case 2: 321 __asm("movw %1, %0" : "=m" (*(volatile uint16_t *)va) 322 : "a" ((uint16_t)data)); 323 break; 324 case 1: 325 __asm("movb %1, %0" : "=m" (*(volatile uint8_t *)va) 326 : "a" ((uint8_t)data)); 327 break; 328 } 329 } 330