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path: root/drivers/acpi/acpica/exfield.c
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Diffstat (limited to 'drivers/acpi/acpica/exfield.c')
-rw-r--r--drivers/acpi/acpica/exfield.c71
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 */