diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/acpi/tables/tbutils.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/drivers/acpi/tables/tbutils.c b/drivers/acpi/tables/tbutils.c index 1da64b4518c..8cc9492ffbf 100644 --- a/drivers/acpi/tables/tbutils.c +++ b/drivers/acpi/tables/tbutils.c @@ -51,6 +51,65 @@ ACPI_MODULE_NAME("tbutils") static acpi_physical_address acpi_tb_get_root_table_entry(u8 * table_entry, acpi_native_uint table_entry_size); +/******************************************************************************* + * + * FUNCTION: acpi_tb_check_xsdt + * + * PARAMETERS: address - Pointer to the XSDT + * + * RETURN: status + * AE_OK - XSDT is okay + * AE_NO_MEMORY - can't map XSDT + * AE_INVALID_TABLE_LENGTH - invalid table length + * AE_NULL_ENTRY - XSDT has NULL entry + * + * DESCRIPTION: validate XSDT +******************************************************************************/ + +static acpi_status +acpi_tb_check_xsdt(acpi_physical_address address) +{ + struct acpi_table_header *table; + u32 length; + u64 xsdt_entry_address; + u8 *table_entry; + u32 table_count; + int i; + + table = acpi_os_map_memory(address, sizeof(struct acpi_table_header)); + if (!table) + return AE_NO_MEMORY; + + length = table->length; + acpi_os_unmap_memory(table, sizeof(struct acpi_table_header)); + if (length < sizeof(struct acpi_table_header)) + return AE_INVALID_TABLE_LENGTH; + + table = acpi_os_map_memory(address, length); + if (!table) + return AE_NO_MEMORY; + + /* Calculate the number of tables described in XSDT */ + table_count = + (u32) ((table->length - + sizeof(struct acpi_table_header)) / sizeof(u64)); + table_entry = + ACPI_CAST_PTR(u8, table) + sizeof(struct acpi_table_header); + for (i = 0; i < table_count; i++) { + ACPI_MOVE_64_TO_64(&xsdt_entry_address, table_entry); + if (!xsdt_entry_address) { + /* XSDT has NULL entry */ + break; + } + table_entry += sizeof(u64); + } + acpi_os_unmap_memory(table, length); + + if (i < table_count) + return AE_NULL_ENTRY; + else + return AE_OK; +} /******************************************************************************* * @@ -341,6 +400,7 @@ acpi_tb_parse_root_table(acpi_physical_address rsdp_address, u8 flags) u32 table_count; struct acpi_table_header *table; acpi_physical_address address; + acpi_physical_address rsdt_address; u32 length; u8 *table_entry; acpi_status status; @@ -369,6 +429,8 @@ acpi_tb_parse_root_table(acpi_physical_address rsdp_address, u8 flags) */ address = (acpi_physical_address) rsdp->xsdt_physical_address; table_entry_size = sizeof(u64); + rsdt_address = (acpi_physical_address) + rsdp->rsdt_physical_address; } else { /* Root table is an RSDT (32-bit physical addresses) */ @@ -382,6 +444,15 @@ acpi_tb_parse_root_table(acpi_physical_address rsdp_address, u8 flags) */ acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp)); + if (table_entry_size == sizeof(u64)) { + if (acpi_tb_check_xsdt(address) == AE_NULL_ENTRY) { + /* XSDT has NULL entry, RSDT is used */ + address = rsdt_address; + table_entry_size = sizeof(u32); + ACPI_WARNING((AE_INFO, "BIOS XSDT has NULL entry," + "using RSDT")); + } + } /* Map the RSDT/XSDT table header to get the full table length */ table = acpi_os_map_memory(address, sizeof(struct acpi_table_header)); |