arch/x86/kernel/aperture_64.c

   1 /*
   2  * Firmware replacement code.
   3  *
   4  * Work around broken BIOSes that don't set an aperture, only set the
   5  * aperture in the AGP bridge, or set too small aperture.
   6  *
   7  * If all fails map the aperture over some low memory.  This is cheaper than
   8  * doing bounce buffering. The memory is lost. This is done at early boot
   9  * because only the bootmem allocator can allocate 32+MB.
  10  *
  11  * Copyright 2002 Andi Kleen, SuSE Labs.
  12  */
  13 #define pr_fmt(fmt) "AGP: " fmt
  14
  15 #include <linux/kernel.h>
  16 #include <linux/types.h>
  17 #include <linux/init.h>
  18 #include <linux/memblock.h>
  19 #include <linux/mmzone.h>
  20 #include <linux/pci_ids.h>
  21 #include <linux/pci.h>
  22 #include <linux/bitops.h>
  23 #include <linux/suspend.h>
  24 #include <asm/e820.h>
  25 #include <asm/io.h>
  26 #include <asm/iommu.h>
  27 #include <asm/gart.h>
  28 #include <asm/pci-direct.h>
  29 #include <asm/dma.h>
  30 #include <asm/amd_nb.h>
  31 #include <asm/x86_init.h>
  32
  33 /*
  34  * Using 512M as goal, in case kexec will load kernel_big
  35  * that will do the on-position decompress, and could overlap with
  36  * with the gart aperture that is used.
  37  * Sequence:
  38  * kernel_small
  39  * ==> kexec (with kdump trigger path or gart still enabled)
  40  * ==> kernel_small (gart area become e820_reserved)
  41  * ==> kexec (with kdump trigger path or gart still enabled)
  42  * ==> kerne_big (uncompressed size will be big than 64M or 128M)
  43  * So don't use 512M below as gart iommu, leave the space for kernel
  44  * code for safe.
  45  */
  46 #define GART_MIN_ADDR   (512ULL << 20)
  47 #define GART_MAX_ADDR   (1ULL   << 32)
  48
  49 int gart_iommu_aperture;
  50 int gart_iommu_aperture_disabled __initdata;
  51 int gart_iommu_aperture_allowed __initdata;
  52
  53 int fallback_aper_order __initdata = 1; /* 64MB */
  54 int fallback_aper_force __initdata;
  55
  56 int fix_aperture __initdata = 1;
  57
  58 /* This code runs before the PCI subsystem is initialized, so just
  59    access the northbridge directly. */
  60
  61 static u32 __init allocate_aperture(void)
  62 {
  63         u32 aper_size;
  64         unsigned long addr;
  65
  66         /* aper_size should <= 1G */
  67         if (fallback_aper_order > 5)
  68                 fallback_aper_order = 5;
  69         aper_size = (32 * 1024 * 1024) << fallback_aper_order;
  70
  71         /*
  72          * Aperture has to be naturally aligned. This means a 2GB aperture
  73          * won't have much chance of finding a place in the lower 4GB of
  74          * memory. Unfortunately we cannot move it up because that would
  75          * make the IOMMU useless.
  76          */
  77         addr = memblock_find_in_range(GART_MIN_ADDR, GART_MAX_ADDR,
  78                                       aper_size, aper_size);
  79         if (!addr) {
  80                 pr_err("Cannot allocate aperture memory hole [mem %#010lx-%#010lx] (%uKB)\n",
  81                        addr, addr + aper_size - 1, aper_size >> 10);
  82                 return 0;
  83         }
  84         memblock_reserve(addr, aper_size);
  85         pr_info("Mapping aperture over RAM [mem %#010lx-%#010lx] (%uKB)\n",
  86                 addr, addr + aper_size - 1, aper_size >> 10);
  87         register_nosave_region(addr >> PAGE_SHIFT,
  88                                (addr+aper_size) >> PAGE_SHIFT);
  89
  90         return (u32)addr;
  91 }
  92
  93
  94 /* Find a PCI capability */
  95 static u32 __init find_cap(int bus, int slot, int func, int cap)
  96 {
  97         int bytes;
  98         u8 pos;
  99
 100         if (!(read_pci_config_16(bus, slot, func, PCI_STATUS) &
 101                                                 PCI_STATUS_CAP_LIST))
 102                 return 0;
 103
 104         pos = read_pci_config_byte(bus, slot, func, PCI_CAPABILITY_LIST);
 105         for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) {
 106                 u8 id;
 107
 108                 pos &= ~3;
 109                 id = read_pci_config_byte(bus, slot, func, pos+PCI_CAP_LIST_ID);
 110                 if (id == 0xff)
 111                         break;
 112                 if (id == cap)
 113                         return pos;
 114                 pos = read_pci_config_byte(bus, slot, func,
 115                                                 pos+PCI_CAP_LIST_NEXT);
 116         }
 117         return 0;
 118 }
 119
 120 /* Read a standard AGPv3 bridge header */
 121 static u32 __init read_agp(int bus, int slot, int func, int cap, u32 *order)
 122 {
 123         u32 apsize;
 124         u32 apsizereg;
 125         int nbits;
 126         u32 aper_low, aper_hi;
 127         u64 aper;
 128         u32 old_order;
 129
 130         pr_info("pci 0000:%02x:%02x:%02x: AGP bridge\n", bus, slot, func);
 131         apsizereg = read_pci_config_16(bus, slot, func, cap + 0x14);
 132         if (apsizereg == 0xffffffff) {
 133                 pr_err("pci 0000:%02x:%02x.%d: APSIZE unreadable\n",
 134                        bus, slot, func);
 135                 return 0;
 136         }
 137
 138         /* old_order could be the value from NB gart setting */
 139         old_order = *order;
 140
 141         apsize = apsizereg & 0xfff;
 142         /* Some BIOS use weird encodings not in the AGPv3 table. */
 143         if (apsize & 0xff)
 144                 apsize |= 0xf00;
 145         nbits = hweight16(apsize);
 146         *order = 7 - nbits;
 147         if ((int)*order < 0) /* < 32MB */
 148                 *order = 0;
 149
 150         aper_low = read_pci_config(bus, slot, func, 0x10);
 151         aper_hi = read_pci_config(bus, slot, func, 0x14);
 152         aper = (aper_low & ~((1<<22)-1)) | ((u64)aper_hi << 32);
 153
 154         /*
 155          * On some sick chips, APSIZE is 0. It means it wants 4G
 156          * so let double check that order, and lets trust AMD NB settings:
 157          */
 158         pr_info("pci 0000:%02x:%02x.%d: AGP aperture [bus addr %#010Lx-%#010Lx] (old size %uMB)\n",
 159                 bus, slot, func, aper, aper + (32ULL << (old_order + 20)) - 1,
 160                 32 << old_order);
 161         if (aper + (32ULL<<(20 + *order)) > 0x100000000ULL) {
 162                 pr_info("pci 0000:%02x:%02x.%d: AGP aperture size %uMB (APSIZE %#x) is not right, using settings from NB\n",
 163                         bus, slot, func, 32 << *order, apsizereg);
 164                 *order = old_order;
 165         }
 166
 167         pr_info("pci 0000:%02x:%02x.%d: AGP aperture [bus addr %#010Lx-%#010Lx] (%uMB, APSIZE %#x)\n",
 168                 bus, slot, func, aper, aper + (32ULL << (*order + 20)) - 1,
 169                 32 << *order, apsizereg);
 170
 171         if (!aperture_valid(aper, (32*1024*1024) << *order, 32<<20))
 172                 return 0;
 173         return (u32)aper;
 174 }
 175
 176 /*
 177  * Look for an AGP bridge. Windows only expects the aperture in the
 178  * AGP bridge and some BIOS forget to initialize the Northbridge too.
 179  * Work around this here.
 180  *
 181  * Do an PCI bus scan by hand because we're running before the PCI
 182  * subsystem.
 183  *
 184  * All AMD AGP bridges are AGPv3 compliant, so we can do this scan
 185  * generically. It's probably overkill to always scan all slots because
 186  * the AGP bridges should be always an own bus on the HT hierarchy,
 187  * but do it here for future safety.
 188  */
 189 static u32 __init search_agp_bridge(u32 *order, int *valid_agp)
 190 {
 191         int bus, slot, func;
 192
 193         /* Poor man's PCI discovery */
 194         for (bus = 0; bus < 256; bus++) {
 195                 for (slot = 0; slot < 32; slot++) {
 196                         for (func = 0; func < 8; func++) {
 197                                 u32 class, cap;
 198                                 u8 type;
 199                                 class = read_pci_config(bus, slot, func,
 200                                                         PCI_CLASS_REVISION);
 201                                 if (class == 0xffffffff)
 202                                         break;
 203
 204                                 switch (class >> 16) {
 205                                 case PCI_CLASS_BRIDGE_HOST:
 206                                 case PCI_CLASS_BRIDGE_OTHER: /* needed? */
 207                                         /* AGP bridge? */
 208                                         cap = find_cap(bus, slot, func,
 209                                                         PCI_CAP_ID_AGP);
 210                                         if (!cap)
 211                                                 break;
 212                                         *valid_agp = 1;
 213                                         return read_agp(bus, slot, func, cap,
 214                                                         order);
 215                                 }
 216
 217                                 /* No multi-function device? */
 218                                 type = read_pci_config_byte(bus, slot, func,
 219                                                                PCI_HEADER_TYPE);
 220                                 if (!(type & 0x80))
 221                                         break;
 222                         }
 223                 }
 224         }
 225         pr_info("No AGP bridge found\n");
 226
 227         return 0;
 228 }
 229
 230 static int gart_fix_e820 __initdata = 1;
 231
 232 static int __init parse_gart_mem(char *p)
 233 {
 234         if (!p)
 235                 return -EINVAL;
 236
 237         if (!strncmp(p, "off", 3))
 238                 gart_fix_e820 = 0;
 239         else if (!strncmp(p, "on", 2))
 240                 gart_fix_e820 = 1;
 241
 242         return 0;
 243 }
 244 early_param("gart_fix_e820", parse_gart_mem);
 245
 246 void __init early_gart_iommu_check(void)
 247 {
 248         /*
 249          * in case it is enabled before, esp for kexec/kdump,
 250          * previous kernel already enable that. memset called
 251          * by allocate_aperture/__alloc_bootmem_nopanic cause restart.
 252          * or second kernel have different position for GART hole. and new
 253          * kernel could use hole as RAM that is still used by GART set by
 254          * first kernel
 255          * or BIOS forget to put that in reserved.
 256          * try to update e820 to make that region as reserved.
 257          */
 258         u32 agp_aper_order = 0;
 259         int i, fix, slot, valid_agp = 0;
 260         u32 ctl;
 261         u32 aper_size = 0, aper_order = 0, last_aper_order = 0;
 262         u64 aper_base = 0, last_aper_base = 0;
 263         int aper_enabled = 0, last_aper_enabled = 0, last_valid = 0;
 264
 265         if (!early_pci_allowed())
 266                 return;
 267
 268         /* This is mostly duplicate of iommu_hole_init */
 269         search_agp_bridge(&agp_aper_order, &valid_agp);
 270
 271         fix = 0;
 272         for (i = 0; amd_nb_bus_dev_ranges[i].dev_limit; i++) {
 273                 int bus;
 274                 int dev_base, dev_limit;
 275
 276                 bus = amd_nb_bus_dev_ranges[i].bus;
 277                 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
 278                 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
 279
 280                 for (slot = dev_base; slot < dev_limit; slot++) {
 281                         if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
 282                                 continue;
 283
 284                         ctl = read_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL);
 285                         aper_enabled = ctl & GARTEN;
 286                         aper_order = (ctl >> 1) & 7;
 287                         aper_size = (32 * 1024 * 1024) << aper_order;
 288                         aper_base = read_pci_config(bus, slot, 3, AMD64_GARTAPERTUREBASE) & 0x7fff;
 289                         aper_base <<= 25;
 290
 291                         if (last_valid) {
 292                                 if ((aper_order != last_aper_order) ||
 293                                     (aper_base != last_aper_base) ||
 294                                     (aper_enabled != last_aper_enabled)) {
 295                                         fix = 1;
 296                                         break;
 297                                 }
 298                         }
 299
 300                         last_aper_order = aper_order;
 301                         last_aper_base = aper_base;
 302                         last_aper_enabled = aper_enabled;
 303                         last_valid = 1;
 304                 }
 305         }
 306
 307         if (!fix && !aper_enabled)
 308                 return;
 309
 310         if (!aper_base || !aper_size || aper_base + aper_size > 0x100000000UL)
 311                 fix = 1;
 312
 313         if (gart_fix_e820 && !fix && aper_enabled) {
 314                 if (e820_any_mapped(aper_base, aper_base + aper_size,
 315                                     E820_RAM)) {
 316                         /* reserve it, so we can reuse it in second kernel */
 317                         pr_info("e820: reserve [mem %#010Lx-%#010Lx] for GART\n",
 318                                 aper_base, aper_base + aper_size - 1);
 319                         e820_add_region(aper_base, aper_size, E820_RESERVED);
 320                         update_e820();
 321                 }
 322         }
 323
 324         if (valid_agp)
 325                 return;
 326
 327         /* disable them all at first */
 328         for (i = 0; i < amd_nb_bus_dev_ranges[i].dev_limit; i++) {
 329                 int bus;
 330                 int dev_base, dev_limit;
 331
 332                 bus = amd_nb_bus_dev_ranges[i].bus;
 333                 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
 334                 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
 335
 336                 for (slot = dev_base; slot < dev_limit; slot++) {
 337                         if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
 338                                 continue;
 339
 340                         ctl = read_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL);
 341                         ctl &= ~GARTEN;
 342                         write_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL, ctl);
 343                 }
 344         }
 345
 346 }
 347
 348 static int __initdata printed_gart_size_msg;
 349
 350 int __init gart_iommu_hole_init(void)
 351 {
 352         u32 agp_aper_base = 0, agp_aper_order = 0;
 353         u32 aper_size, aper_alloc = 0, aper_order = 0, last_aper_order = 0;
 354         u64 aper_base, last_aper_base = 0;
 355         int fix, slot, valid_agp = 0;
 356         int i, node;
 357
 358         if (gart_iommu_aperture_disabled || !fix_aperture ||
 359             !early_pci_allowed())
 360                 return -ENODEV;
 361
 362         pr_info("Checking aperture...\n");
 363
 364         if (!fallback_aper_force)
 365                 agp_aper_base = search_agp_bridge(&agp_aper_order, &valid_agp);
 366
 367         fix = 0;
 368         node = 0;
 369         for (i = 0; i < amd_nb_bus_dev_ranges[i].dev_limit; i++) {
 370                 int bus;
 371                 int dev_base, dev_limit;
 372                 u32 ctl;
 373
 374                 bus = amd_nb_bus_dev_ranges[i].bus;
 375                 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
 376                 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
 377
 378                 for (slot = dev_base; slot < dev_limit; slot++) {
 379                         if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
 380                                 continue;
 381
 382                         iommu_detected = 1;
 383                         gart_iommu_aperture = 1;
 384                         x86_init.iommu.iommu_init = gart_iommu_init;
 385
 386                         ctl = read_pci_config(bus, slot, 3,
 387                                               AMD64_GARTAPERTURECTL);
 388
 389                         /*
 390                          * Before we do anything else disable the GART. It may
 391                          * still be enabled if we boot into a crash-kernel here.
 392                          * Reconfiguring the GART while it is enabled could have
 393                          * unknown side-effects.
 394                          */
 395                         ctl &= ~GARTEN;
 396                         write_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL, ctl);
 397
 398                         aper_order = (ctl >> 1) & 7;
 399                         aper_size = (32 * 1024 * 1024) << aper_order;
 400                         aper_base = read_pci_config(bus, slot, 3, AMD64_GARTAPERTUREBASE) & 0x7fff;
 401                         aper_base <<= 25;
 402
 403                         pr_info("Node %d: aperture [bus addr %#010Lx-%#010Lx] (%uMB)\n",
 404                                 node, aper_base, aper_base + aper_size - 1,
 405                                 aper_size >> 20);
 406                         node++;
 407
 408                         if (!aperture_valid(aper_base, aper_size, 64<<20)) {
 409                                 if (valid_agp && agp_aper_base &&
 410                                     agp_aper_base == aper_base &&
 411                                     agp_aper_order == aper_order) {
 412                                         /* the same between two setting from NB and agp */
 413                                         if (!no_iommu &&
 414                                             max_pfn > MAX_DMA32_PFN &&
 415                                             !printed_gart_size_msg) {
 416                                                 pr_err("you are using iommu with agp, but GART size is less than 64MB\n");
 417                                                 pr_err("please increase GART size in your BIOS setup\n");
 418                                                 pr_err("if BIOS doesn't have that option, contact your HW vendor!\n");
 419                                                 printed_gart_size_msg = 1;
 420                                         }
 421                                 } else {
 422                                         fix = 1;
 423                                         goto out;
 424                                 }
 425                         }
 426
 427                         if ((last_aper_order && aper_order != last_aper_order) ||
 428                             (last_aper_base && aper_base != last_aper_base)) {
 429                                 fix = 1;
 430                                 goto out;
 431                         }
 432                         last_aper_order = aper_order;
 433                         last_aper_base = aper_base;
 434                 }
 435         }
 436
 437 out:
 438         if (!fix && !fallback_aper_force) {
 439                 if (last_aper_base)
 440                         return 1;
 441                 return 0;
 442         }
 443
 444         if (!fallback_aper_force) {
 445                 aper_alloc = agp_aper_base;
 446                 aper_order = agp_aper_order;
 447         }
 448
 449         if (aper_alloc) {
 450                 /* Got the aperture from the AGP bridge */
 451         } else if ((!no_iommu && max_pfn > MAX_DMA32_PFN) ||
 452                    force_iommu ||
 453                    valid_agp ||
 454                    fallback_aper_force) {
 455                 pr_info("Your BIOS doesn't leave a aperture memory hole\n");
 456                 pr_info("Please enable the IOMMU option in the BIOS setup\n");
 457                 pr_info("This costs you %dMB of RAM\n",
 458                         32 << fallback_aper_order);
 459
 460                 aper_order = fallback_aper_order;
 461                 aper_alloc = allocate_aperture();
 462                 if (!aper_alloc) {
 463                         /*
 464                          * Could disable AGP and IOMMU here, but it's
 465                          * probably not worth it. But the later users
 466                          * cannot deal with bad apertures and turning
 467                          * on the aperture over memory causes very
 468                          * strange problems, so it's better to panic
 469                          * early.
 470                          */
 471                         panic("Not enough memory for aperture");
 472                 }
 473         } else {
 474                 return 0;
 475         }
 476
 477         /* Fix up the north bridges */
 478         for (i = 0; i < amd_nb_bus_dev_ranges[i].dev_limit; i++) {
 479                 int bus, dev_base, dev_limit;
 480
 481                 /*
 482                  * Don't enable translation yet but enable GART IO and CPU
 483                  * accesses and set DISTLBWALKPRB since GART table memory is UC.
 484                  */
 485                 u32 ctl = aper_order << 1;
 486
 487                 bus = amd_nb_bus_dev_ranges[i].bus;
 488                 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
 489                 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
 490                 for (slot = dev_base; slot < dev_limit; slot++) {
 491                         if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
 492                                 continue;
 493
 494                         write_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL, ctl);
 495                         write_pci_config(bus, slot, 3, AMD64_GARTAPERTUREBASE, aper_alloc >> 25);
 496                 }
 497         }
 498
 499         set_up_gart_resume(aper_order, aper_alloc);
 500
 501         return 1;
 502 }