ACPICA: Fixes for load() operator.

Optimized the Load operator in the case where the source operand is an
operation region. Simply map the operation region memory, instead of
performing a bytewise read.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 38 insertions, 132 deletions

diff --git a/drivers/acpi/executer/exconfig.c b/drivers/acpi/executer/exconfig.c
index 7aa18f93f95d..61ec855b5d61 100644
--- a/drivers/acpi/executer/exconfig.c
+++ b/drivers/acpi/executer/exconfig.c
@@ -119,7 +119,7 @@ acpi_ex_add_table(acpi_native_uint table_index,
  *
  * RETURN:      Status
  *
- * DESCRIPTION: Load an ACPI table
+ * DESCRIPTION: Load an ACPI table from the RSDT/XSDT
  *
  ******************************************************************************/
 
@@ -138,21 +138,7 @@ acpi_ex_load_table_op(struct acpi_walk_state *walk_state,
 
         ACPI_FUNCTION_TRACE(ex_load_table_op);
 
-#if 0
-        /*
-         * Make sure that the signature does not match one of the tables that
-         * is already loaded.
-         */
-        status = acpi_tb_match_signature(operand[0]->string.pointer, NULL);
-        if (status == AE_OK) {
-
-                /* Signature matched -- don't allow override */
-
-                return_ACPI_STATUS(AE_ALREADY_EXISTS);
-        }
-#endif
-
-        /* Find the ACPI table */
+        /* Find the ACPI table in the RSDT/XSDT */
 
         status = acpi_tb_find_table(operand[0]->string.pointer,
                                     operand[1]->string.pointer,
@@ -256,7 +242,7 @@ acpi_ex_load_table_op(struct acpi_walk_state *walk_state,
  *
  * FUNCTION:    acpi_ex_load_op
  *
- * PARAMETERS:  obj_desc        - Region or Field where the table will be
+ * PARAMETERS:  obj_desc        - Region or Buffer/Field where the table will be
  *                                obtained
  *              Target          - Where a handle to the table will be stored
  *              walk_state      - Current state
@@ -265,6 +251,12 @@ acpi_ex_load_table_op(struct acpi_walk_state *walk_state,
  *
  * DESCRIPTION: Load an ACPI table from a field or operation region
  *
+ * NOTE: Region Fields (Field, bank_field, index_fields) are resolved to buffer
+ *       objects before this code is reached.
+ *
+ *       If source is an operation region, it must refer to system_memory, as
+ *       per the ACPI specification.
+ *
  ******************************************************************************/
 
 acpi_status
@@ -272,24 +264,26 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,
                 union acpi_operand_object *target,
                 struct acpi_walk_state *walk_state)
 {
-        acpi_status status;
         union acpi_operand_object *ddb_handle;
-        union acpi_operand_object *buffer_desc = NULL;
-        struct acpi_table_header *table_ptr = NULL;
-        acpi_native_uint table_index;
-        acpi_physical_address address;
-        struct acpi_table_header table_header;
         struct acpi_table_desc table_desc;
-        acpi_integer temp;
-        u32 i;
+        acpi_native_uint table_index;
+        acpi_status status;
 
         ACPI_FUNCTION_TRACE(ex_load_op);
 
-        /* Object can be either an op_region or a Field */
         ACPI_MEMSET(&table_desc, 0, sizeof(struct acpi_table_desc));
+
+        /* Source Object can be either an op_region or a Buffer/Field */
+
         switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {
         case ACPI_TYPE_REGION:
 
+                /* Region must be system_memory (from ACPI spec) */
+
+                if (obj_desc->region.space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
+                        return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
+                }
+
                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Load from Region %p %s\n",
                                   obj_desc,
                                   acpi_ut_get_object_type_name(obj_desc)));
@@ -305,113 +299,31 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,
                         }
                 }
 
-                /* Get the base physical address of the region */
-
-                address = obj_desc->region.address;
-
-                /* Get part of the table header to get the table length */
-
-                table_header.length = 0;
-                for (i = 0; i < 8; i++) {
-                        status =
-                            acpi_ev_address_space_dispatch(obj_desc, ACPI_READ,
-                                                           (acpi_physical_address)
-                                                           (i + address), 8,
-                                                           &temp);
-                        if (ACPI_FAILURE(status)) {
-                                return_ACPI_STATUS(status);
-                        }
-
-                        /* Get the one valid byte of the returned 64-bit value */
-
-                        ACPI_CAST_PTR(u8, &table_header)[i] = (u8) temp;
-                }
-
-                /* Sanity check the table length */
-
-                if (table_header.length < sizeof(struct acpi_table_header)) {
-                        return_ACPI_STATUS(AE_BAD_HEADER);
-                }
-
-                /* Allocate a buffer for the entire table */
-
-                table_ptr = ACPI_ALLOCATE(table_header.length);
-                if (!table_ptr) {
-                        return_ACPI_STATUS(AE_NO_MEMORY);
-                }
-
-                /* Get the entire table from the op region */
-
-                for (i = 0; i < table_header.length; i++) {
-                        status =
-                            acpi_ev_address_space_dispatch(obj_desc, ACPI_READ,
-                                                           (acpi_physical_address)
-                                                           (i + address), 8,
-                                                           &temp);
-                        if (ACPI_FAILURE(status)) {
-                                goto cleanup;
-                        }
-
-                        /* Get the one valid byte of the returned 64-bit value */
-
-                        ACPI_CAST_PTR(u8, table_ptr)[i] = (u8) temp;
-                }
+                table_desc.address = obj_desc->region.address;
+                table_desc.length = obj_desc->region.length;
+                table_desc.flags = ACPI_TABLE_ORIGIN_MAPPED;
                 break;
 
-        case ACPI_TYPE_LOCAL_REGION_FIELD:
-        case ACPI_TYPE_LOCAL_BANK_FIELD:
-        case ACPI_TYPE_LOCAL_INDEX_FIELD:
+        case ACPI_TYPE_BUFFER:  /* Buffer or resolved region_field */
 
-                ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Load from Field %p %s\n",
-                                  obj_desc,
-                                  acpi_ut_get_object_type_name(obj_desc)));
+                /* Simply extract the buffer from the buffer object */
 
-                /*
-                 * The length of the field must be at least as large as the table.
-                 * Read the entire field and thus the entire table.  Buffer is
-                 * allocated during the read.
-                 */
-                status =
-                    acpi_ex_read_data_from_field(walk_state, obj_desc,
-                                                 &buffer_desc);
-                if (ACPI_FAILURE(status)) {
-                        return_ACPI_STATUS(status);
-                }
-
-                table_ptr = ACPI_CAST_PTR(struct acpi_table_header,
-                                          buffer_desc->buffer.pointer);
-
-                /* All done with the buffer_desc, delete it */
-
-                buffer_desc->buffer.pointer = NULL;
-                acpi_ut_remove_reference(buffer_desc);
+                ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
+                                  "Load from Buffer or Field %p %s\n", obj_desc,
+                                  acpi_ut_get_object_type_name(obj_desc)));
 
-                /* Sanity check the table length */
+                table_desc.pointer = ACPI_CAST_PTR(struct acpi_table_header,
+                                                   obj_desc->buffer.pointer);
+                table_desc.length = table_desc.pointer->length;
+                table_desc.flags = ACPI_TABLE_ORIGIN_ALLOCATED;
 
-                if (table_ptr->length < sizeof(struct acpi_table_header)) {
-                        status = AE_BAD_HEADER;
-                        goto cleanup;
-                }
+                obj_desc->buffer.pointer = NULL;
                 break;
 
         default:
                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
         }
 
-        /* The table must be either an SSDT or a PSDT */
-
-        if ((!ACPI_COMPARE_NAME(table_ptr->signature, ACPI_SIG_PSDT)) &&
-            (!ACPI_COMPARE_NAME(table_ptr->signature, ACPI_SIG_SSDT))) {
-                ACPI_ERROR((AE_INFO,
-                            "Table has invalid signature [%4.4s], must be SSDT or PSDT",
-                            table_ptr->signature));
-                status = AE_BAD_SIGNATURE;
-                goto cleanup;
-        }
-
-        table_desc.pointer = table_ptr;
-        table_desc.length = table_ptr->length;
-        table_desc.flags = ACPI_TABLE_ORIGIN_ALLOCATED;
         /*
          * Install the new table into the local data structures
          */
@@ -440,13 +352,9 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,
                 return_ACPI_STATUS(status);
         }
 
-        ACPI_INFO((AE_INFO,
-                   "Dynamic SSDT Load - OemId [%6.6s] OemTableId [%8.8s]",
-                   table_ptr->oem_id, table_ptr->oem_table_id));
-
       cleanup:
         if (ACPI_FAILURE(status)) {
-                ACPI_FREE(table_ptr);
+                acpi_tb_delete_table(&table_desc);
         }
         return_ACPI_STATUS(status);
 }
diff --git a/drivers/acpi/executer/exresop.c b/drivers/acpi/executer/exresop.c
index 4c93d0972333..411d12092d29 100644
--- a/drivers/acpi/executer/exresop.c
+++ b/drivers/acpi/executer/exresop.c
@@ -611,22 +611,20 @@ acpi_ex_resolve_operands(u16 opcode,
                         }
                         goto next_operand;
 
-                case ARGI_REGION_OR_FIELD:
+                case ARGI_REGION_OR_BUFFER:     /* Used by Load() only */
 
-                        /* Need an operand of type REGION or a FIELD in a region */
+                        /* Need an operand of type REGION or a BUFFER (which could be a resolved region field) */
 
                         switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {
+                        case ACPI_TYPE_BUFFER:
                         case ACPI_TYPE_REGION:
-                        case ACPI_TYPE_LOCAL_REGION_FIELD:
-                        case ACPI_TYPE_LOCAL_BANK_FIELD:
-                        case ACPI_TYPE_LOCAL_INDEX_FIELD:
 
                                 /* Valid operand */
                                 break;
 
                         default:
                                 ACPI_ERROR((AE_INFO,
-                                            "Needed [Region/RegionField], found [%s] %p",
+                                            "Needed [Region/Buffer], found [%s] %p",
                                             acpi_ut_get_object_type_name
                                             (obj_desc), obj_desc));