[PATCH v1 3/8] ACPI: bus: Split _OSC evaluation out of acpi_run_osc()

Rafael J. Wysocki
2025-12-18T20:43:26Z

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Split a function for evaluating _OSL called acpi_eval_osc() out of
acpi_run_osc() to facilitate subsequent changes and add some more
parameters sanity checks to the latter.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/acpi/bus.c | 89 ++++++++++++++++++++++++++++++-----------------------
1 file changed, 52 insertions(+), 37 deletions(-)

--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -195,52 +195,67 @@ static void acpi_dump_osc_data(acpi_hand
OSC_INVALID_REVISION_ERROR | \
OSC_CAPABILITIES_MASK_ERROR)

-acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
+static int acpi_eval_osc(acpi_handle handle, guid_t *guid, int rev,
+ struct acpi_buffer *cap,
+ union acpi_object in_params[static 4],
+ struct acpi_buffer *output)
{
- acpi_status status;
struct acpi_object_list input;
- union acpi_object in_params[4];
union acpi_object *out_obj;
+ acpi_status status;
+
+ in_params[0].type = ACPI_TYPE_BUFFER;
+ in_params[0].buffer.length = sizeof(*guid);
+ in_params[0].buffer.pointer = (u8 *)guid;
+ in_params[1].type = ACPI_TYPE_INTEGER;
+ in_params[1].integer.value = rev;
+ in_params[2].type = ACPI_TYPE_INTEGER;
+ in_params[2].integer.value = cap->length / sizeof(u32);
+ in_params[3].type = ACPI_TYPE_BUFFER;
+ in_params[3].buffer.length = cap->length;
+ in_params[3].buffer.pointer = cap->pointer;
+ input.pointer = in_params;
+ input.count = 4;
+
+ output->length = ACPI_ALLOCATE_BUFFER;
+ output->pointer = NULL;
+
+ status = acpi_evaluate_object(handle, "_OSC", &input, output);
+ if (ACPI_FAILURE(status) || !output->length)
+ return -ENODATA;
+
+ out_obj = output->pointer;
+ if (out_obj->type != ACPI_TYPE_BUFFER ||
+ out_obj->buffer.length != cap->length) {
+ acpi_handle_debug(handle, "Invalid _OSC return buffer\n");
+ acpi_dump_osc_data(handle, guid, rev, cap);
+ ACPI_FREE(out_obj);
+ return -ENODATA;
+ }
+
+ return 0;
+}
+
+acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
+{
+ union acpi_object in_params[4], *out_obj;
+ struct acpi_buffer output;
+ acpi_status status = AE_OK;
guid_t guid;
u32 errors;
- struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
+ int ret;

- if (!context)
+ if (!context || !context->cap.pointer ||
+ context->cap.length < 2 * sizeof(32) ||
+ guid_parse(context->uuid_str, &guid))
+ return AE_BAD_PARAMETER;
+
+ ret = acpi_eval_osc(handle, &guid, context->rev, &context->cap,
+ in_params, &output);
+ if (ret)
return AE_ERROR;
- if (guid_parse(context->uuid_str, &guid))
- return AE_ERROR;
- context->ret.length = ACPI_ALLOCATE_BUFFER;
- context->ret.pointer = NULL;
-
- /* Setting up input parameters */
- input.count = 4;
- input.pointer = in_params;
- in_params[0].type = ACPI_TYPE_BUFFER;
- in_params[0].buffer.length = 16;
- in_params[0].buffer.pointer = (u8 *)&guid;
- in_params[1].type = ACPI_TYPE_INTEGER;
- in_params[1].integer.value = context->rev;
- in_params[2].type = ACPI_TYPE_INTEGER;
- in_params[2].integer.value = context->cap.length/sizeof(u32);
- in_params[3].type = ACPI_TYPE_BUFFER;
- in_params[3].buffer.length = context->cap.length;
- in_params[3].buffer.pointer = context->cap.pointer;
-
- status = acpi_evaluate_object(handle, "_OSC", &input, &output);
- if (ACPI_FAILURE(status))
- return status;
-
- if (!output.length)
- return AE_NULL_OBJECT;

out_obj = output.pointer;
- if (out_obj->type != ACPI_TYPE_BUFFER
- || out_obj->buffer.length != context->cap.length) {
- acpi_handle_debug(handle, "_OSC evaluation returned wrong type");
- acpi_dump_osc_data(handle, &guid, context->rev, &context->cap);
- status = AE_TYPE;
- goto out_kfree;
- }
/* Only take defined error bits into account. */
errors = *((u32 *)out_obj->buffer.pointer) & OSC_ERROR_MASK;
/* If OSC_QUERY_ENABLE is set, ignore the "capabilities masked" bit. */