diff options
Diffstat (limited to 'arch/x86/boot/compressed/acpi.c')
-rw-r--r-- | arch/x86/boot/compressed/acpi.c | 315 |
1 files changed, 315 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c new file mode 100644 index 0000000000..9caf89063e --- /dev/null +++ b/arch/x86/boot/compressed/acpi.c @@ -0,0 +1,315 @@ +// SPDX-License-Identifier: GPL-2.0 +#define BOOT_CTYPE_H +#include "misc.h" +#include "error.h" +#include "../string.h" +#include "efi.h" + +#include <linux/numa.h> + +/* + * Longest parameter of 'acpi=' is 'copy_dsdt', plus an extra '\0' + * for termination. + */ +#define MAX_ACPI_ARG_LENGTH 10 + +/* + * Immovable memory regions representation. Max amount of memory regions is + * MAX_NUMNODES*2. + */ +struct mem_vector immovable_mem[MAX_NUMNODES*2]; + +static acpi_physical_address +__efi_get_rsdp_addr(unsigned long cfg_tbl_pa, unsigned int cfg_tbl_len) +{ +#ifdef CONFIG_EFI + unsigned long rsdp_addr; + int ret; + + /* + * Search EFI system tables for RSDP. Preferred is ACPI_20_TABLE_GUID to + * ACPI_TABLE_GUID because it has more features. + */ + rsdp_addr = efi_find_vendor_table(boot_params, cfg_tbl_pa, cfg_tbl_len, + ACPI_20_TABLE_GUID); + if (rsdp_addr) + return (acpi_physical_address)rsdp_addr; + + /* No ACPI_20_TABLE_GUID found, fallback to ACPI_TABLE_GUID. */ + rsdp_addr = efi_find_vendor_table(boot_params, cfg_tbl_pa, cfg_tbl_len, + ACPI_TABLE_GUID); + if (rsdp_addr) + return (acpi_physical_address)rsdp_addr; + + debug_putstr("Error getting RSDP address.\n"); +#endif + return 0; +} + +static acpi_physical_address efi_get_rsdp_addr(void) +{ +#ifdef CONFIG_EFI + unsigned long cfg_tbl_pa = 0; + unsigned int cfg_tbl_len; + unsigned long systab_pa; + unsigned int nr_tables; + enum efi_type et; + int ret; + + et = efi_get_type(boot_params); + if (et == EFI_TYPE_NONE) + return 0; + + systab_pa = efi_get_system_table(boot_params); + if (!systab_pa) + error("EFI support advertised, but unable to locate system table."); + + ret = efi_get_conf_table(boot_params, &cfg_tbl_pa, &cfg_tbl_len); + if (ret || !cfg_tbl_pa) + error("EFI config table not found."); + + return __efi_get_rsdp_addr(cfg_tbl_pa, cfg_tbl_len); +#else + return 0; +#endif +} + +static u8 compute_checksum(u8 *buffer, u32 length) +{ + u8 *end = buffer + length; + u8 sum = 0; + + while (buffer < end) + sum += *(buffer++); + + return sum; +} + +/* Search a block of memory for the RSDP signature. */ +static u8 *scan_mem_for_rsdp(u8 *start, u32 length) +{ + struct acpi_table_rsdp *rsdp; + u8 *address, *end; + + end = start + length; + + /* Search from given start address for the requested length */ + for (address = start; address < end; address += ACPI_RSDP_SCAN_STEP) { + /* + * Both RSDP signature and checksum must be correct. + * Note: Sometimes there exists more than one RSDP in memory; + * the valid RSDP has a valid checksum, all others have an + * invalid checksum. + */ + rsdp = (struct acpi_table_rsdp *)address; + + /* BAD Signature */ + if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature)) + continue; + + /* Check the standard checksum */ + if (compute_checksum((u8 *)rsdp, ACPI_RSDP_CHECKSUM_LENGTH)) + continue; + + /* Check extended checksum if table version >= 2 */ + if ((rsdp->revision >= 2) && + (compute_checksum((u8 *)rsdp, ACPI_RSDP_XCHECKSUM_LENGTH))) + continue; + + /* Signature and checksum valid, we have found a real RSDP */ + return address; + } + return NULL; +} + +/* Search RSDP address in EBDA. */ +static acpi_physical_address bios_get_rsdp_addr(void) +{ + unsigned long address; + u8 *rsdp; + + /* Get the location of the Extended BIOS Data Area (EBDA) */ + address = *(u16 *)ACPI_EBDA_PTR_LOCATION; + address <<= 4; + + /* + * Search EBDA paragraphs (EBDA is required to be a minimum of + * 1K length) + */ + if (address > 0x400) { + rsdp = scan_mem_for_rsdp((u8 *)address, ACPI_EBDA_WINDOW_SIZE); + if (rsdp) + return (acpi_physical_address)(unsigned long)rsdp; + } + + /* Search upper memory: 16-byte boundaries in E0000h-FFFFFh */ + rsdp = scan_mem_for_rsdp((u8 *) ACPI_HI_RSDP_WINDOW_BASE, + ACPI_HI_RSDP_WINDOW_SIZE); + if (rsdp) + return (acpi_physical_address)(unsigned long)rsdp; + + return 0; +} + +/* Return RSDP address on success, otherwise 0. */ +acpi_physical_address get_rsdp_addr(void) +{ + acpi_physical_address pa; + + pa = boot_params->acpi_rsdp_addr; + + if (!pa) + pa = efi_get_rsdp_addr(); + + if (!pa) + pa = bios_get_rsdp_addr(); + + return pa; +} + +#if defined(CONFIG_RANDOMIZE_BASE) && defined(CONFIG_MEMORY_HOTREMOVE) +/* + * Max length of 64-bit hex address string is 19, prefix "0x" + 16 hex + * digits, and '\0' for termination. + */ +#define MAX_ADDR_LEN 19 + +static unsigned long get_cmdline_acpi_rsdp(void) +{ + unsigned long addr = 0; + +#ifdef CONFIG_KEXEC + char val[MAX_ADDR_LEN] = { }; + int ret; + + ret = cmdline_find_option("acpi_rsdp", val, MAX_ADDR_LEN); + if (ret < 0) + return 0; + + if (boot_kstrtoul(val, 16, &addr)) + return 0; +#endif + return addr; +} + +/* Compute SRAT address from RSDP. */ +static unsigned long get_acpi_srat_table(void) +{ + unsigned long root_table, acpi_table; + struct acpi_table_header *header; + struct acpi_table_rsdp *rsdp; + u32 num_entries, size, len; + char arg[10]; + u8 *entry; + + /* + * Check whether we were given an RSDP on the command line. We don't + * stash this in boot params because the kernel itself may have + * different ideas about whether to trust a command-line parameter. + */ + rsdp = (struct acpi_table_rsdp *)get_cmdline_acpi_rsdp(); + if (!rsdp) + rsdp = (struct acpi_table_rsdp *)(long) + boot_params->acpi_rsdp_addr; + + if (!rsdp) + return 0; + + /* Get ACPI root table from RSDP.*/ + if (!(cmdline_find_option("acpi", arg, sizeof(arg)) == 4 && + !strncmp(arg, "rsdt", 4)) && + rsdp->xsdt_physical_address && + rsdp->revision > 1) { + root_table = rsdp->xsdt_physical_address; + size = ACPI_XSDT_ENTRY_SIZE; + } else { + root_table = rsdp->rsdt_physical_address; + size = ACPI_RSDT_ENTRY_SIZE; + } + + if (!root_table) + return 0; + + header = (struct acpi_table_header *)root_table; + len = header->length; + if (len < sizeof(struct acpi_table_header) + size) + return 0; + + num_entries = (len - sizeof(struct acpi_table_header)) / size; + entry = (u8 *)(root_table + sizeof(struct acpi_table_header)); + + while (num_entries--) { + if (size == ACPI_RSDT_ENTRY_SIZE) + acpi_table = *(u32 *)entry; + else + acpi_table = *(u64 *)entry; + + if (acpi_table) { + header = (struct acpi_table_header *)acpi_table; + + if (ACPI_COMPARE_NAMESEG(header->signature, ACPI_SIG_SRAT)) + return acpi_table; + } + entry += size; + } + return 0; +} + +/** + * count_immovable_mem_regions - Parse SRAT and cache the immovable + * memory regions into the immovable_mem array. + * + * Return the number of immovable memory regions on success, 0 on failure: + * + * - Too many immovable memory regions + * - ACPI off or no SRAT found + * - No immovable memory region found. + */ +int count_immovable_mem_regions(void) +{ + unsigned long table_addr, table_end, table; + struct acpi_subtable_header *sub_table; + struct acpi_table_header *table_header; + char arg[MAX_ACPI_ARG_LENGTH]; + int num = 0; + + if (cmdline_find_option("acpi", arg, sizeof(arg)) == 3 && + !strncmp(arg, "off", 3)) + return 0; + + table_addr = get_acpi_srat_table(); + if (!table_addr) + return 0; + + table_header = (struct acpi_table_header *)table_addr; + table_end = table_addr + table_header->length; + table = table_addr + sizeof(struct acpi_table_srat); + + while (table + sizeof(struct acpi_subtable_header) < table_end) { + + sub_table = (struct acpi_subtable_header *)table; + if (!sub_table->length) { + debug_putstr("Invalid zero length SRAT subtable.\n"); + return 0; + } + + if (sub_table->type == ACPI_SRAT_TYPE_MEMORY_AFFINITY) { + struct acpi_srat_mem_affinity *ma; + + ma = (struct acpi_srat_mem_affinity *)sub_table; + if (!(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) && ma->length) { + immovable_mem[num].start = ma->base_address; + immovable_mem[num].size = ma->length; + num++; + } + + if (num >= MAX_NUMNODES*2) { + debug_putstr("Too many immovable memory regions, aborting.\n"); + return 0; + } + } + table += sub_table->length; + } + return num; +} +#endif /* CONFIG_RANDOMIZE_BASE && CONFIG_MEMORY_HOTREMOVE */ |