ACPI / extlog: replace open-coded _DSM code with helper functions

Use helper functions to simplify _DSM related code in acpi_extlog driver.
Also mark initialization data and functions with __init and __initdata
to reduce memory footprint.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Tested-by: Chen, Gong <gong.chen@linux.intel.com>
Reviewed-by: Chen, Gong <gong.chen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 12 insertions, 49 deletions

diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c
index a6869e110ce5..928c4db83ddf 100644
--- a/drivers/acpi/acpi_extlog.c
+++ b/drivers/acpi/acpi_extlog.c
@@ -20,11 +20,9 @@
 #define EXT_ELOG_ENTRY_MASK     GENMASK_ULL(51, 0) /* elog entry address mask */
 
 #define EXTLOG_DSM_REV          0x0
-#define EXTLOG_FN_QUERY         0x0
 #define EXTLOG_FN_ADDR          0x1
 
 #define FLAG_OS_OPTIN           BIT(0)
-#define EXTLOG_QUERY_L1_EXIST   BIT(1)
 #define ELOG_ENTRY_VALID        (1ULL<<63)
 #define ELOG_ENTRY_LEN          0x1000
 
@@ -43,7 +41,7 @@ struct extlog_l1_head {
         u8  rev1[12];
 };
 
-static u8 extlog_dsm_uuid[] = "663E35AF-CC10-41A4-88EA-5470AF055295";
+static u8 extlog_dsm_uuid[] __initdata = "663E35AF-CC10-41A4-88EA-5470AF055295";
 
 /* L1 table related physical address */
 static u64 elog_base;
@@ -153,62 +151,27 @@ static int extlog_print(struct notifier_block *nb, unsigned long val,
         return NOTIFY_DONE;
 }
 
-static int extlog_get_dsm(acpi_handle handle, int rev, int func, u64 *ret)
+static bool __init extlog_get_l1addr(void)
 {
-        struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
-        struct acpi_object_list input;
-        union acpi_object params[4], *obj;
         u8 uuid[16];
-        int i;
+        acpi_handle handle;
+        union acpi_object *obj;
 
         acpi_str_to_uuid(extlog_dsm_uuid, uuid);
-        input.count = 4;
-        input.pointer = params;
-        params[0].type = ACPI_TYPE_BUFFER;
-        params[0].buffer.length = 16;
-        params[0].buffer.pointer = uuid;
-        params[1].type = ACPI_TYPE_INTEGER;
-        params[1].integer.value = rev;
-        params[2].type = ACPI_TYPE_INTEGER;
-        params[2].integer.value = func;
-        params[3].type = ACPI_TYPE_PACKAGE;
-        params[3].package.count = 0;
-        params[3].package.elements = NULL;
-
-        if (ACPI_FAILURE(acpi_evaluate_object(handle, "_DSM", &input, &buf)))
-                return -1;
-
-        *ret = 0;
-        obj = (union acpi_object *)buf.pointer;
-        if (obj->type == ACPI_TYPE_INTEGER) {
-                *ret = obj->integer.value;
-        } else if (obj->type == ACPI_TYPE_BUFFER) {
-                if (obj->buffer.length <= 8) {
-                        for (i = 0; i < obj->buffer.length; i++)
-                                *ret |= (obj->buffer.pointer[i] << (i * 8));
-                }
-        }
-        kfree(buf.pointer);
-
-        return 0;
-}
-
-static bool extlog_get_l1addr(void)
-{
-        acpi_handle handle;
-        u64 ret;
 
         if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
                 return false;
-
-        if (extlog_get_dsm(handle, EXTLOG_DSM_REV, EXTLOG_FN_QUERY, &ret) ||
-            !(ret & EXTLOG_QUERY_L1_EXIST))
+        if (!acpi_check_dsm(handle, uuid, EXTLOG_DSM_REV, 1 << EXTLOG_FN_ADDR))
                 return false;
-
-        if (extlog_get_dsm(handle, EXTLOG_DSM_REV, EXTLOG_FN_ADDR, &ret))
+        obj = acpi_evaluate_dsm_typed(handle, uuid, EXTLOG_DSM_REV,
+                                      EXTLOG_FN_ADDR, NULL, ACPI_TYPE_INTEGER);
+        if (!obj) {
                 return false;
+        } else {
+                l1_dirbase = obj->integer.value;
+                ACPI_FREE(obj);
+        }
 
-        l1_dirbase = ret;
         /* Spec says L1 directory must be 4K aligned, bail out if it isn't */
         if (l1_dirbase & ((1 << 12) - 1)) {
                 pr_warn(FW_BUG "L1 Directory is invalid at physical %llx\n",