diff options
Diffstat (limited to 'drivers/acpi/acpica/exfield.c')
| -rw-r--r-- | drivers/acpi/acpica/exfield.c | 71 |
1 files changed, 70 insertions, 1 deletions
diff --git a/drivers/acpi/acpica/exfield.c b/drivers/acpi/acpica/exfield.c index e5798f15793a..d3d2dbfba680 100644 --- a/drivers/acpi/acpica/exfield.c +++ b/drivers/acpi/acpica/exfield.c @@ -3,7 +3,7 @@ * * Module Name: exfield - AML execution - field_unit read/write * - * Copyright (C) 2000 - 2018, Intel Corp. + * Copyright (C) 2000 - 2019, Intel Corp. * *****************************************************************************/ @@ -41,6 +41,17 @@ const u8 acpi_protocol_lengths[] = { 0xFF /* F - ATTRIB_RAW_PROCESS_BYTES */ }; +#define PCC_MASTER_SUBSPACE 3 + +/* + * The following macros determine a given offset is a COMD field. + * According to the specification, generic subspaces (types 0-2) contains a + * 2-byte COMD field at offset 4 and master subspaces (type 3) contains a 4-byte + * COMD field starting at offset 12. + */ +#define GENERIC_SUBSPACE_COMMAND(a) (4 == a || a == 5) +#define MASTER_SUBSPACE_COMMAND(a) (12 <= a && a <= 15) + /******************************************************************************* * * FUNCTION: acpi_ex_get_protocol_buffer_length @@ -177,6 +188,25 @@ acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state, status = acpi_ex_read_gpio(obj_desc, buffer); goto exit; + } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) && + (obj_desc->field.region_obj->region.space_id == + ACPI_ADR_SPACE_PLATFORM_COMM)) { + /* + * Reading from a PCC field unit does not require the handler because + * it only requires reading from the internal_pcc_buffer. + */ + ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, + "PCC FieldRead bits %u\n", + obj_desc->field.bit_length)); + + memcpy(buffer, + obj_desc->field.region_obj->field.internal_pcc_buffer + + obj_desc->field.base_byte_offset, + (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field. + bit_length)); + + *ret_buffer_desc = buffer_desc; + return AE_OK; } ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, @@ -229,6 +259,7 @@ acpi_ex_write_data_to_field(union acpi_operand_object *source_desc, { acpi_status status; u32 buffer_length; + u32 data_length; void *buffer; ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc); @@ -272,6 +303,44 @@ acpi_ex_write_data_to_field(union acpi_operand_object *source_desc, acpi_ex_write_serial_bus(source_desc, obj_desc, result_desc); return_ACPI_STATUS(status); + } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) && + (obj_desc->field.region_obj->region.space_id == + ACPI_ADR_SPACE_PLATFORM_COMM)) { + /* + * According to the spec a write to the COMD field will invoke the + * region handler. Otherwise, write to the pcc_internal buffer. This + * implementation will use the offsets specified rather than the name + * of the field. This is considered safer because some firmware tools + * are known to obfiscate named objects. + */ + data_length = + (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field. + bit_length); + memcpy(obj_desc->field.region_obj->field.internal_pcc_buffer + + obj_desc->field.base_byte_offset, + source_desc->buffer.pointer, data_length); + + if ((obj_desc->field.region_obj->region.address == + PCC_MASTER_SUBSPACE + && MASTER_SUBSPACE_COMMAND(obj_desc->field. + base_byte_offset)) + || GENERIC_SUBSPACE_COMMAND(obj_desc->field. + base_byte_offset)) { + + /* Perform the write */ + + ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, + "PCC COMD field has been written. Invoking PCC handler now.\n")); + + status = + acpi_ex_access_region(obj_desc, 0, + (u64 *)obj_desc->field. + region_obj->field. + internal_pcc_buffer, + ACPI_WRITE); + return_ACPI_STATUS(status); + } + return (AE_OK); } /* Get a pointer to the data to be written */ |