Merge branch 'acpi-dsm'

* acpi-dsm:
  ACPI / extlog: replace open-coded _DSM code with helper functions
  ACPI / nouveau: replace open-coded _DSM code with helper functions
  nouveau / ACPI: fix memory leak in ACPI _DSM related code
  ACPI / i915: replace open-coded _DSM code with helper functions
  ACPI / i2c-hid: replace open-coded _DSM code with helper functions
  ACPI / TPM: detect PPI features by checking availability of _DSM functions
  ACPI / TPM: replace open-coded _DSM code with helper functions
  ACPI / TPM: match node name instead of full path when searching for TPM device
  PCI / pci-label: treat PCI label with index 0 as valid label
  ACPI / PCI: replace open-coded _DSM code with helper functions
  PCI / pci-label: release allocated ACPI object on error recovery path
  ACPI: introduce helper interfaces for _DSM method

2 files changed, 109 insertions, 49 deletions

diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c
index 2635a01c5b3e..94166680b3a3 100644
--- a/drivers/acpi/acpi_extlog.c
+++ b/drivers/acpi/acpi_extlog.c
@@ -19,11 +19,9 @@
 #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
 
@@ -42,7 +40,7 @@ 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;
@@ -152,62 +150,27 @@ 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",
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index 1336b9151479..0347a37eb438 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -572,3 +572,100 @@ acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
 
         return status;
 }
+
+/**
+ * acpi_evaluate_dsm - evaluate device's _DSM method
+ * @handle: ACPI device handle
+ * @uuid: UUID of requested functions, should be 16 bytes
+ * @rev: revision number of requested function
+ * @func: requested function number
+ * @argv4: the function specific parameter
+ *
+ * Evaluate device's _DSM method with specified UUID, revision id and
+ * function number. Caller needs to free the returned object.
+ *
+ * Though ACPI defines the fourth parameter for _DSM should be a package,
+ * some old BIOSes do expect a buffer or an integer etc.
+ */
+union acpi_object *
+acpi_evaluate_dsm(acpi_handle handle, const u8 *uuid, int rev, int func,
+                  union acpi_object *argv4)
+{
+        acpi_status ret;
+        struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
+        union acpi_object params[4];
+        struct acpi_object_list input = {
+                .count = 4,
+                .pointer = params,
+        };
+
+        params[0].type = ACPI_TYPE_BUFFER;
+        params[0].buffer.length = 16;
+        params[0].buffer.pointer = (char *)uuid;
+        params[1].type = ACPI_TYPE_INTEGER;
+        params[1].integer.value = rev;
+        params[2].type = ACPI_TYPE_INTEGER;
+        params[2].integer.value = func;
+        if (argv4) {
+                params[3] = *argv4;
+        } else {
+                params[3].type = ACPI_TYPE_PACKAGE;
+                params[3].package.count = 0;
+                params[3].package.elements = NULL;
+        }
+
+        ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);
+        if (ACPI_SUCCESS(ret))
+                return (union acpi_object *)buf.pointer;
+
+        if (ret != AE_NOT_FOUND)
+                acpi_handle_warn(handle,
+                                "failed to evaluate _DSM (0x%x)\n", ret);
+
+        return NULL;
+}
+EXPORT_SYMBOL(acpi_evaluate_dsm);
+
+/**
+ * acpi_check_dsm - check if _DSM method supports requested functions.
+ * @handle: ACPI device handle
+ * @uuid: UUID of requested functions, should be 16 bytes at least
+ * @rev: revision number of requested functions
+ * @funcs: bitmap of requested functions
+ * @exclude: excluding special value, used to support i915 and nouveau
+ *
+ * Evaluate device's _DSM method to check whether it supports requested
+ * functions. Currently only support 64 functions at maximum, should be
+ * enough for now.
+ */
+bool acpi_check_dsm(acpi_handle handle, const u8 *uuid, int rev, u64 funcs)
+{
+        int i;
+        u64 mask = 0;
+        union acpi_object *obj;
+
+        if (funcs == 0)
+                return false;
+
+        obj = acpi_evaluate_dsm(handle, uuid, rev, 0, NULL);
+        if (!obj)
+                return false;
+
+        /* For compatibility, old BIOSes may return an integer */
+        if (obj->type == ACPI_TYPE_INTEGER)
+                mask = obj->integer.value;
+        else if (obj->type == ACPI_TYPE_BUFFER)
+                for (i = 0; i < obj->buffer.length && i < 8; i++)
+                        mask |= (((u8)obj->buffer.pointer[i]) << (i * 8));
+        ACPI_FREE(obj);
+
+        /*
+         * Bit 0 indicates whether there's support for any functions other than
+         * function 0 for the specified UUID and revision.
+         */
+        if ((mask & 0x1) && (mask & funcs) == funcs)
+                return true;
+
+        return false;
+}
+EXPORT_SYMBOL(acpi_check_dsm);