arch/x86/boot/compressed/acpi.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #define BOOT_CTYPE_H
   3 #include "misc.h"
   4 #include "error.h"
   5 #include "../string.h"
   6
   7 #include <linux/numa.h>
   8 #include <linux/efi.h>
   9 #include <asm/efi.h>
  10
  11 /*
  12  * Longest parameter of 'acpi=' is 'copy_dsdt', plus an extra '\0'
  13  * for termination.
  14  */
  15 #define MAX_ACPI_ARG_LENGTH 10
  16
  17 /*
  18  * Immovable memory regions representation. Max amount of memory regions is
  19  * MAX_NUMNODES*2.
  20  */
  21 struct mem_vector immovable_mem[MAX_NUMNODES*2];
  22
  23 /*
  24  * Max length of 64-bit hex address string is 19, prefix "0x" + 16 hex
  25  * digits, and '\0' for termination.
  26  */
  27 #define MAX_ADDR_LEN 19
  28
  29 static acpi_physical_address get_cmdline_acpi_rsdp(void)
  30 {
  31         acpi_physical_address addr = 0;
  32
  33 #ifdef CONFIG_KEXEC
  34         char val[MAX_ADDR_LEN] = { };
  35         int ret;
  36
  37         ret = cmdline_find_option("acpi_rsdp", val, MAX_ADDR_LEN);
  38         if (ret < 0)
  39                 return 0;
  40
  41         if (kstrtoull(val, 16, &addr))
  42                 return 0;
  43 #endif
  44         return addr;
  45 }
  46
  47 /*
  48  * Search EFI system tables for RSDP.  If both ACPI_20_TABLE_GUID and
  49  * ACPI_TABLE_GUID are found, take the former, which has more features.
  50  */
  51 static acpi_physical_address
  52 __efi_get_rsdp_addr(unsigned long config_tables, unsigned int nr_tables,
  53                     bool efi_64)
  54 {
  55         acpi_physical_address rsdp_addr = 0;
  56
  57 #ifdef CONFIG_EFI
  58         int i;
  59
  60         /* Get EFI tables from systab. */
  61         for (i = 0; i < nr_tables; i++) {
  62                 acpi_physical_address table;
  63                 efi_guid_t guid;
  64
  65                 if (efi_64) {
  66                         efi_config_table_64_t *tbl = (efi_config_table_64_t *)config_tables + i;
  67
  68                         guid  = tbl->guid;
  69                         table = tbl->table;
  70
  71                         if (!IS_ENABLED(CONFIG_X86_64) && table >> 32) {
  72                                 debug_putstr("Error getting RSDP address: EFI config table located above 4GB.\n");
  73                                 return 0;
  74                         }
  75                 } else {
  76                         efi_config_table_32_t *tbl = (efi_config_table_32_t *)config_tables + i;
  77
  78                         guid  = tbl->guid;
  79                         table = tbl->table;
  80                 }
  81
  82                 if (!(efi_guidcmp(guid, ACPI_TABLE_GUID)))
  83                         rsdp_addr = table;
  84                 else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID)))
  85                         return table;
  86         }
  87 #endif
  88         return rsdp_addr;
  89 }
  90
  91 /* EFI/kexec support is 64-bit only. */
  92 #ifdef CONFIG_X86_64
  93 static struct efi_setup_data *get_kexec_setup_data_addr(void)
  94 {
  95         struct setup_data *data;
  96         u64 pa_data;
  97
  98         pa_data = boot_params->hdr.setup_data;
  99         while (pa_data) {
 100                 data = (struct setup_data *)pa_data;
 101                 if (data->type == SETUP_EFI)
 102                         return (struct efi_setup_data *)(pa_data + sizeof(struct setup_data));
 103
 104                 pa_data = data->next;
 105         }
 106         return NULL;
 107 }
 108
 109 static acpi_physical_address kexec_get_rsdp_addr(void)
 110 {
 111         efi_system_table_64_t *systab;
 112         struct efi_setup_data *esd;
 113         struct efi_info *ei;
 114         char *sig;
 115
 116         esd = (struct efi_setup_data *)get_kexec_setup_data_addr();
 117         if (!esd)
 118                 return 0;
 119
 120         if (!esd->tables) {
 121                 debug_putstr("Wrong kexec SETUP_EFI data.\n");
 122                 return 0;
 123         }
 124
 125         ei = &boot_params->efi_info;
 126         sig = (char *)&ei->efi_loader_signature;
 127         if (strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) {
 128                 debug_putstr("Wrong kexec EFI loader signature.\n");
 129                 return 0;
 130         }
 131
 132         /* Get systab from boot params. */
 133         systab = (efi_system_table_64_t *) (ei->efi_systab | ((__u64)ei->efi_systab_hi << 32));
 134         if (!systab)
 135                 error("EFI system table not found in kexec boot_params.");
 136
 137         return __efi_get_rsdp_addr((unsigned long)esd->tables, systab->nr_tables, true);
 138 }
 139 #else
 140 static acpi_physical_address kexec_get_rsdp_addr(void) { return 0; }
 141 #endif /* CONFIG_X86_64 */
 142
 143 static acpi_physical_address efi_get_rsdp_addr(void)
 144 {
 145 #ifdef CONFIG_EFI
 146         unsigned long systab, config_tables;
 147         unsigned int nr_tables;
 148         struct efi_info *ei;
 149         bool efi_64;
 150         char *sig;
 151
 152         ei = &boot_params->efi_info;
 153         sig = (char *)&ei->efi_loader_signature;
 154
 155         if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) {
 156                 efi_64 = true;
 157         } else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4)) {
 158                 efi_64 = false;
 159         } else {
 160                 debug_putstr("Wrong EFI loader signature.\n");
 161                 return 0;
 162         }
 163
 164         /* Get systab from boot params. */
 165 #ifdef CONFIG_X86_64
 166         systab = ei->efi_systab | ((__u64)ei->efi_systab_hi << 32);
 167 #else
 168         if (ei->efi_systab_hi || ei->efi_memmap_hi) {
 169                 debug_putstr("Error getting RSDP address: EFI system table located above 4GB.\n");
 170                 return 0;
 171         }
 172         systab = ei->efi_systab;
 173 #endif
 174         if (!systab)
 175                 error("EFI system table not found.");
 176
 177         /* Handle EFI bitness properly */
 178         if (efi_64) {
 179                 efi_system_table_64_t *stbl = (efi_system_table_64_t *)systab;
 180
 181                 config_tables   = stbl->tables;
 182                 nr_tables       = stbl->nr_tables;
 183         } else {
 184                 efi_system_table_32_t *stbl = (efi_system_table_32_t *)systab;
 185
 186                 config_tables   = stbl->tables;
 187                 nr_tables       = stbl->nr_tables;
 188         }
 189
 190         if (!config_tables)
 191                 error("EFI config tables not found.");
 192
 193         return __efi_get_rsdp_addr(config_tables, nr_tables, efi_64);
 194 #else
 195         return 0;
 196 #endif
 197 }
 198
 199 static u8 compute_checksum(u8 *buffer, u32 length)
 200 {
 201         u8 *end = buffer + length;
 202         u8 sum = 0;
 203
 204         while (buffer < end)
 205                 sum += *(buffer++);
 206
 207         return sum;
 208 }
 209
 210 /* Search a block of memory for the RSDP signature. */
 211 static u8 *scan_mem_for_rsdp(u8 *start, u32 length)
 212 {
 213         struct acpi_table_rsdp *rsdp;
 214         u8 *address, *end;
 215
 216         end = start + length;
 217
 218         /* Search from given start address for the requested length */
 219         for (address = start; address < end; address += ACPI_RSDP_SCAN_STEP) {
 220                 /*
 221                  * Both RSDP signature and checksum must be correct.
 222                  * Note: Sometimes there exists more than one RSDP in memory;
 223                  * the valid RSDP has a valid checksum, all others have an
 224                  * invalid checksum.
 225                  */
 226                 rsdp = (struct acpi_table_rsdp *)address;
 227
 228                 /* BAD Signature */
 229                 if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature))
 230                         continue;
 231
 232                 /* Check the standard checksum */
 233                 if (compute_checksum((u8 *)rsdp, ACPI_RSDP_CHECKSUM_LENGTH))
 234                         continue;
 235
 236                 /* Check extended checksum if table version >= 2 */
 237                 if ((rsdp->revision >= 2) &&
 238                     (compute_checksum((u8 *)rsdp, ACPI_RSDP_XCHECKSUM_LENGTH)))
 239                         continue;
 240
 241                 /* Signature and checksum valid, we have found a real RSDP */
 242                 return address;
 243         }
 244         return NULL;
 245 }
 246
 247 /* Search RSDP address in EBDA. */
 248 static acpi_physical_address bios_get_rsdp_addr(void)
 249 {
 250         unsigned long address;
 251         u8 *rsdp;
 252
 253         /* Get the location of the Extended BIOS Data Area (EBDA) */
 254         address = *(u16 *)ACPI_EBDA_PTR_LOCATION;
 255         address <<= 4;
 256
 257         /*
 258          * Search EBDA paragraphs (EBDA is required to be a minimum of
 259          * 1K length)
 260          */
 261         if (address > 0x400) {
 262                 rsdp = scan_mem_for_rsdp((u8 *)address, ACPI_EBDA_WINDOW_SIZE);
 263                 if (rsdp)
 264                         return (acpi_physical_address)(unsigned long)rsdp;
 265         }
 266
 267         /* Search upper memory: 16-byte boundaries in E0000h-FFFFFh */
 268         rsdp = scan_mem_for_rsdp((u8 *) ACPI_HI_RSDP_WINDOW_BASE,
 269                                         ACPI_HI_RSDP_WINDOW_SIZE);
 270         if (rsdp)
 271                 return (acpi_physical_address)(unsigned long)rsdp;
 272
 273         return 0;
 274 }
 275
 276 /* Return RSDP address on success, otherwise 0. */
 277 acpi_physical_address get_rsdp_addr(void)
 278 {
 279         acpi_physical_address pa;
 280
 281         pa = boot_params->acpi_rsdp_addr;
 282
 283         /*
 284          * Try to get EFI data from setup_data. This can happen when we're a
 285          * kexec'ed kernel and kexec(1) has passed all the required EFI info to
 286          * us.
 287          */
 288         if (!pa)
 289                 pa = kexec_get_rsdp_addr();
 290
 291         if (!pa)
 292                 pa = efi_get_rsdp_addr();
 293
 294         if (!pa)
 295                 pa = bios_get_rsdp_addr();
 296
 297         return pa;
 298 }
 299
 300 #if defined(CONFIG_RANDOMIZE_BASE) && defined(CONFIG_MEMORY_HOTREMOVE)
 301 /* Compute SRAT address from RSDP. */
 302 static unsigned long get_acpi_srat_table(void)
 303 {
 304         unsigned long root_table, acpi_table;
 305         struct acpi_table_header *header;
 306         struct acpi_table_rsdp *rsdp;
 307         u32 num_entries, size, len;
 308         char arg[10];
 309         u8 *entry;
 310
 311         /*
 312          * Check whether we were given an RSDP on the command line. We don't
 313          * stash this in boot params because the kernel itself may have
 314          * different ideas about whether to trust a command-line parameter.
 315          */
 316         rsdp = (struct acpi_table_rsdp *)get_cmdline_acpi_rsdp();
 317
 318         if (!rsdp)
 319                 rsdp = (struct acpi_table_rsdp *)(long)
 320                         boot_params->acpi_rsdp_addr;
 321
 322         if (!rsdp)
 323                 return 0;
 324
 325         /* Get ACPI root table from RSDP.*/
 326         if (!(cmdline_find_option("acpi", arg, sizeof(arg)) == 4 &&
 327             !strncmp(arg, "rsdt", 4)) &&
 328             rsdp->xsdt_physical_address &&
 329             rsdp->revision > 1) {
 330                 root_table = rsdp->xsdt_physical_address;
 331                 size = ACPI_XSDT_ENTRY_SIZE;
 332         } else {
 333                 root_table = rsdp->rsdt_physical_address;
 334                 size = ACPI_RSDT_ENTRY_SIZE;
 335         }
 336
 337         if (!root_table)
 338                 return 0;
 339
 340         header = (struct acpi_table_header *)root_table;
 341         len = header->length;
 342         if (len < sizeof(struct acpi_table_header) + size)
 343                 return 0;
 344
 345         num_entries = (len - sizeof(struct acpi_table_header)) / size;
 346         entry = (u8 *)(root_table + sizeof(struct acpi_table_header));
 347
 348         while (num_entries--) {
 349                 if (size == ACPI_RSDT_ENTRY_SIZE)
 350                         acpi_table = *(u32 *)entry;
 351                 else
 352                         acpi_table = *(u64 *)entry;
 353
 354                 if (acpi_table) {
 355                         header = (struct acpi_table_header *)acpi_table;
 356
 357                         if (ACPI_COMPARE_NAMESEG(header->signature, ACPI_SIG_SRAT))
 358                                 return acpi_table;
 359                 }
 360                 entry += size;
 361         }
 362         return 0;
 363 }
 364
 365 /**
 366  * count_immovable_mem_regions - Parse SRAT and cache the immovable
 367  * memory regions into the immovable_mem array.
 368  *
 369  * Return the number of immovable memory regions on success, 0 on failure:
 370  *
 371  * - Too many immovable memory regions
 372  * - ACPI off or no SRAT found
 373  * - No immovable memory region found.
 374  */
 375 int count_immovable_mem_regions(void)
 376 {
 377         unsigned long table_addr, table_end, table;
 378         struct acpi_subtable_header *sub_table;
 379         struct acpi_table_header *table_header;
 380         char arg[MAX_ACPI_ARG_LENGTH];
 381         int num = 0;
 382
 383         if (cmdline_find_option("acpi", arg, sizeof(arg)) == 3 &&
 384             !strncmp(arg, "off", 3))
 385                 return 0;
 386
 387         table_addr = get_acpi_srat_table();
 388         if (!table_addr)
 389                 return 0;
 390
 391         table_header = (struct acpi_table_header *)table_addr;
 392         table_end = table_addr + table_header->length;
 393         table = table_addr + sizeof(struct acpi_table_srat);
 394
 395         while (table + sizeof(struct acpi_subtable_header) < table_end) {
 396                 sub_table = (struct acpi_subtable_header *)table;
 397                 if (sub_table->type == ACPI_SRAT_TYPE_MEMORY_AFFINITY) {
 398                         struct acpi_srat_mem_affinity *ma;
 399
 400                         ma = (struct acpi_srat_mem_affinity *)sub_table;
 401                         if (!(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) && ma->length) {
 402                                 immovable_mem[num].start = ma->base_address;
 403                                 immovable_mem[num].size = ma->length;
 404                                 num++;
 405                         }
 406
 407                         if (num >= MAX_NUMNODES*2) {
 408                                 debug_putstr("Too many immovable memory regions, aborting.\n");
 409                                 return 0;
 410                         }
 411                 }
 412                 table += sub_table->length;
 413         }
 414         return num;
 415 }
 416 #endif /* CONFIG_RANDOMIZE_BASE && CONFIG_MEMORY_HOTREMOVE */