ACPI: PM: s2idle: Refactor common code

Refactor common code to prepare for upcoming changes.
 * Remove unused struct.
 * Print error before returning.
 * Frees ACPI obj if _DSM type is not as expected.
 * Treat lps0_dsm_func_mask as an integer rather than character
 * Remove extra out_obj
 * Move rev_id

Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Pratik Vishwakarma <Pratik.Vishwakarma@amd.com>
Tested-by: Julian Sikorski <belegdol@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c
index da27c1c..c0cba02 100644 (file)
--- a/drivers/acpi/x86/s2idle.c
+++ b/drivers/acpi/x86/s2idle.c
@@ -49,7 +49,7 @@ static const struct acpi_device_id lps0_device_ids[] = {
 
 static acpi_handle lps0_device_handle;
 static guid_t lps0_dsm_guid;
-static char lps0_dsm_func_mask;
+static int lps0_dsm_func_mask;
 
 /* Device constraint entry structure */
 struct lpi_device_info {
@@ -70,15 +70,7 @@ struct lpi_constraints {
        int min_dstate;
 };
 
-/* AMD */
-/* Device constraint entry structure */
-struct lpi_device_info_amd {
-       int revision;
-       int count;
-       union acpi_object *package;
-};
-
-/* Constraint package structure */
+/* AMD Constraint package structure */
 struct lpi_device_constraint_amd {
        char *name;
        int enabled;
@@ -99,12 +91,12 @@ static void lpi_device_get_constraints_amd(void)
                                          rev_id, ACPI_LPS0_GET_DEVICE_CONSTRAINTS,
                                          NULL, ACPI_TYPE_PACKAGE);
 
-       if (!out_obj)
-               return;
-
        acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n",
                          out_obj ? "successful" : "failed");
 
+       if (!out_obj)
+               return;
+
        for (i = 0; i < out_obj->package.count; i++) {
                union acpi_object *package = &out_obj->package.elements[i];
 
@@ -336,11 +328,33 @@ static bool acpi_s2idle_vendor_amd(void)
        return boot_cpu_data.x86_vendor == X86_VENDOR_AMD;
 }
 
+static int validate_dsm(acpi_handle handle, const char *uuid, int rev, guid_t *dsm_guid)
+{
+       union acpi_object *obj;
+       int ret = -EINVAL;
+
+       guid_parse(uuid, dsm_guid);
+       obj = acpi_evaluate_dsm(handle, dsm_guid, rev, 0, NULL);
+
+       /* Check if the _DSM is present and as expected. */
+       if (!obj || obj->type != ACPI_TYPE_BUFFER || obj->buffer.length == 0 ||
+           obj->buffer.length > sizeof(u32)) {
+               acpi_handle_debug(handle,
+                               "_DSM UUID %s rev %d function 0 evaluation failed\n", uuid, rev);
+               goto out;
+       }
+
+       ret = *(int *)obj->buffer.pointer;
+       acpi_handle_debug(handle, "_DSM UUID %s rev %d function mask: 0x%x\n", uuid, rev, ret);
+
+out:
+       ACPI_FREE(obj);
+       return ret;
+}
+
 static int lps0_device_attach(struct acpi_device *adev,
                              const struct acpi_device_id *not_used)
 {
-       union acpi_object *out_obj;
-
        if (lps0_device_handle)
                return 0;
 
@@ -348,28 +362,17 @@ static int lps0_device_attach(struct acpi_device *adev,
                return 0;
 
        if (acpi_s2idle_vendor_amd()) {
-               guid_parse(ACPI_LPS0_DSM_UUID_AMD, &lps0_dsm_guid);
-               out_obj = acpi_evaluate_dsm(adev->handle, &lps0_dsm_guid, 0, 0, NULL);
                rev_id = 0;
+               lps0_dsm_func_mask = validate_dsm(adev->handle,
+                                       ACPI_LPS0_DSM_UUID_AMD, rev_id, &lps0_dsm_guid);
        } else {
-               guid_parse(ACPI_LPS0_DSM_UUID, &lps0_dsm_guid);
-               out_obj = acpi_evaluate_dsm(adev->handle, &lps0_dsm_guid, 1, 0, NULL);
                rev_id = 1;
+               lps0_dsm_func_mask = validate_dsm(adev->handle,
+                                       ACPI_LPS0_DSM_UUID, rev_id, &lps0_dsm_guid);
        }
 
-       /* Check if the _DSM is present and as expected. */
-       if (!out_obj || out_obj->type != ACPI_TYPE_BUFFER) {
-               acpi_handle_debug(adev->handle,
-                                 "_DSM function 0 evaluation failed\n");
-               return 0;
-       }
-
-       lps0_dsm_func_mask = *(char *)out_obj->buffer.pointer;
-
-       ACPI_FREE(out_obj);
-
-       acpi_handle_debug(adev->handle, "_DSM function mask: 0x%x\n",
-                         lps0_dsm_func_mask);
+       if (lps0_dsm_func_mask < 0)
+               return 0;//function eval failed
 
        lps0_device_handle = adev->handle;