diff options
| -rw-r--r-- | drivers/acpi/osl.c | 60 |
1 files changed, 56 insertions, 4 deletions
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index b20b07903218..007224bd4db7 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -681,12 +681,64 @@ acpi_os_table_override(struct acpi_table_header * existing_table, acpi_status acpi_os_physical_table_override(struct acpi_table_header *existing_table, - acpi_physical_address * new_address, - u32 *new_table_length) + acpi_physical_address *address, + u32 *table_length) { - return AE_SUPPORT; -} +#ifndef CONFIG_ACPI_INITRD_TABLE_OVERRIDE + *table_length = 0; + *address = 0; + return AE_OK; +#else + int table_offset = 0; + struct acpi_table_header *table; + + *table_length = 0; + *address = 0; + + if (!acpi_tables_addr) + return AE_OK; + + do { + if (table_offset + ACPI_HEADER_SIZE > all_tables_size) { + WARN_ON(1); + return AE_OK; + } + + table = acpi_os_map_memory(acpi_tables_addr + table_offset, + ACPI_HEADER_SIZE); + + if (table_offset + table->length > all_tables_size) { + acpi_os_unmap_memory(table, ACPI_HEADER_SIZE); + WARN_ON(1); + return AE_OK; + } + table_offset += table->length; + + if (memcmp(existing_table->signature, table->signature, 4)) { + acpi_os_unmap_memory(table, + ACPI_HEADER_SIZE); + continue; + } + + /* Only override tables with matching oem id */ + if (memcmp(table->oem_table_id, existing_table->oem_table_id, + ACPI_OEM_TABLE_ID_SIZE)) { + acpi_os_unmap_memory(table, + ACPI_HEADER_SIZE); + continue; + } + + table_offset -= table->length; + *table_length = table->length; + acpi_os_unmap_memory(table, ACPI_HEADER_SIZE); + *address = acpi_tables_addr + table_offset; + break; + } while (table_offset + ACPI_HEADER_SIZE < all_tables_size); + + return AE_OK; +#endif +} static irqreturn_t acpi_irq(int irq, void *dev_id) { |