diff options
| -rw-r--r-- | drivers/acpi/acpica/exconfig.c | 96 |
1 files changed, 78 insertions, 18 deletions
diff --git a/drivers/acpi/acpica/exconfig.c b/drivers/acpi/acpica/exconfig.c index 0731fd6bad63..eca6f63a53fd 100644 --- a/drivers/acpi/acpica/exconfig.c +++ b/drivers/acpi/acpica/exconfig.c @@ -47,6 +47,7 @@ #include "acnamesp.h" #include "actables.h" #include "acdispat.h" +#include "acevents.h" #define _COMPONENT ACPI_EXECUTER ACPI_MODULE_NAME("exconfig") @@ -57,6 +58,10 @@ acpi_ex_add_table(u32 table_index, struct acpi_namespace_node *parent_node, union acpi_operand_object **ddb_handle); +static acpi_status +acpi_ex_region_read(union acpi_operand_object *obj_desc, + u32 length, u8 *buffer); + /******************************************************************************* * * FUNCTION: acpi_ex_add_table @@ -257,6 +262,48 @@ acpi_ex_load_table_op(struct acpi_walk_state *walk_state, /******************************************************************************* * + * FUNCTION: acpi_ex_region_read + * + * PARAMETERS: obj_desc - Region descriptor + * Length - Number of bytes to read + * Buffer - Pointer to where to put the data + * + * RETURN: Status + * + * DESCRIPTION: Read data from an operation region. The read starts from the + * beginning of the region. + * + ******************************************************************************/ + +static acpi_status +acpi_ex_region_read(union acpi_operand_object *obj_desc, u32 length, u8 *buffer) +{ + acpi_status status; + acpi_integer value; + acpi_physical_address address; + u32 i; + + address = obj_desc->region.address; + + /* Bytewise reads */ + + for (i = 0; i < length; i++) { + status = acpi_ev_address_space_dispatch(obj_desc, ACPI_READ, + address, 8, &value); + if (ACPI_FAILURE(status)) { + return status; + } + + *buffer = (u8)value; + buffer++; + address++; + } + + return AE_OK; +} + +/******************************************************************************* + * * FUNCTION: acpi_ex_load_op * * PARAMETERS: obj_desc - Region or Buffer/Field where the table will be @@ -317,18 +364,23 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc, } } - /* - * Map the table header and get the actual table length. The region - * length is not guaranteed to be the same as the table length. - */ - table = acpi_os_map_memory(obj_desc->region.address, - sizeof(struct acpi_table_header)); + /* Get the table header first so we can get the table length */ + + table = ACPI_ALLOCATE(sizeof(struct acpi_table_header)); if (!table) { return_ACPI_STATUS(AE_NO_MEMORY); } + status = + acpi_ex_region_read(obj_desc, + sizeof(struct acpi_table_header), + ACPI_CAST_PTR(u8, table)); length = table->length; - acpi_os_unmap_memory(table, sizeof(struct acpi_table_header)); + ACPI_FREE(table); + + if (ACPI_FAILURE(status)) { + return_ACPI_STATUS(status); + } /* Must have at least an ACPI table header */ @@ -337,10 +389,19 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc, } /* - * The memory region is not guaranteed to remain stable and we must - * copy the table to a local buffer. For example, the memory region - * is corrupted after suspend on some machines. Dynamically loaded - * tables are usually small, so this overhead is minimal. + * The original implementation simply mapped the table, with no copy. + * However, the memory region is not guaranteed to remain stable and + * we must copy the table to a local buffer. For example, the memory + * region is corrupted after suspend on some machines. Dynamically + * loaded tables are usually small, so this overhead is minimal. + * + * The latest implementation (5/2009) does not use a mapping at all. + * We use the low-level operation region interface to read the table + * instead of the obvious optimization of using a direct mapping. + * This maintains a consistent use of operation regions across the + * entire subsystem. This is important if additional processing must + * be performed in the (possibly user-installed) operation region + * handler. For example, acpi_exec and ASLTS depend on this. */ /* Allocate a buffer for the table */ @@ -350,17 +411,16 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc, return_ACPI_STATUS(AE_NO_MEMORY); } - /* Map the entire table and copy it */ + /* Read the entire table */ - table = acpi_os_map_memory(obj_desc->region.address, length); - if (!table) { + status = acpi_ex_region_read(obj_desc, length, + ACPI_CAST_PTR(u8, + table_desc.pointer)); + if (ACPI_FAILURE(status)) { ACPI_FREE(table_desc.pointer); - return_ACPI_STATUS(AE_NO_MEMORY); + return_ACPI_STATUS(status); } - ACPI_MEMCPY(table_desc.pointer, table, length); - acpi_os_unmap_memory(table, length); - table_desc.address = obj_desc->region.address; break; |