Use helper functions to simplify _DSM related code in pci-label driver.
Also enforce more strict checks on objects returned by _DSM method.
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
---
drivers/pci/pci-label.c | 121 +++++++++++++----------------------------------
1 file changed, 34 insertions(+), 87 deletions(-)
diff --git a/drivers/pci/pci-label.c b/drivers/pci/pci-label.c
index f6e01a5..f12dcd1 100644
--- a/drivers/pci/pci-label.c
+++ b/drivers/pci/pci-label.c
@@ -195,80 +195,58 @@ enum acpi_attr_enum {
static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf)
{
int len;
- len = utf16s_to_utf8s((const wchar_t *)obj->
- package.elements[1].string.pointer,
- obj->package.elements[1].string.length,
+ len = utf16s_to_utf8s((const wchar_t *)obj->string.pointer,
+ obj->string.length,
UTF16_LITTLE_ENDIAN,
buf, PAGE_SIZE);
buf[len] = '\n';
}
static int
-dsm_get_label(acpi_handle handle, int func,
- struct acpi_buffer *output,
- char *buf, enum acpi_attr_enum attribute)
+dsm_get_label(struct device *dev, char *buf, enum acpi_attr_enum attr)
{
- struct acpi_object_list input;
- union acpi_object params[4];
- union acpi_object *obj;
- int len = 0;
-
- int err;
-
- input.count = 4;
- input.pointer = params;
- params[0].type = ACPI_TYPE_BUFFER;
- params[0].buffer.length = sizeof(device_label_dsm_uuid);
- params[0].buffer.pointer = (char *)device_label_dsm_uuid;
- params[1].type = ACPI_TYPE_INTEGER;
- params[1].integer.value = 0x02;
- 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;
-
- err = acpi_evaluate_object(handle, "_DSM", &input, output);
- if (err)
+ acpi_handle handle;
+ union acpi_object *obj, *tmp;
+ int len = -1;
+
+ handle = ACPI_HANDLE(dev);
+ if (!handle)
return -1;
- obj = (union acpi_object *)output->pointer;
- if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 2) {
- len = obj->package.elements[0].integer.value;
+ obj = acpi_evaluate_dsm(handle, device_label_dsm_uuid, 0x2,
+ DEVICE_LABEL_DSM, NULL);
+ if (!obj)
+ return -1;
+
+ tmp = obj->package.elements;
+ if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 2 &&
+ tmp[0].type == ACPI_TYPE_INTEGER &&
+ tmp[1].type == ACPI_TYPE_STRING) {
+ len = tmp[0].integer.value;
if (buf) {
- if (attribute == ACPI_ATTR_INDEX_SHOW)
+ /*
+ * This second string element is optional even when
+ * this _DSM is implemented; when not implemented,
+ * this entry must return a null string.
+ */
+ if (attr == ACPI_ATTR_INDEX_SHOW)
scnprintf(buf, PAGE_SIZE, "%llu\n",
- obj->package.elements[0].integer.value);
- else if (attribute == ACPI_ATTR_LABEL_SHOW)
- dsm_label_utf16s_to_utf8s(obj, buf);
- kfree(output->pointer);
- return strlen(buf);
+ tmp->integer.value);
+ else if (attr == ACPI_ATTR_LABEL_SHOW)
+ dsm_label_utf16s_to_utf8s(tmp + 1, buf);
+ len = strlen(buf) > 0 ? strlen(buf) : -1;
}
- kfree(output->pointer);
- return len;
}
- kfree(output->pointer);
+ ACPI_FREE(obj);
- return -1;
+ return len;
}
static bool
device_has_dsm(struct device *dev)
{
- acpi_handle handle;
- struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
-
- handle = ACPI_HANDLE(dev);
-
- if (!handle)
- return FALSE;
-
- if (dsm_get_label(handle, DEVICE_LABEL_DSM, &output, NULL,
- ACPI_ATTR_NONE) > 0)
- return TRUE;
-
- return FALSE;
+ return dsm_get_label(dev, NULL, ACPI_ATTR_NONE) > 0;
}
static umode_t
@@ -287,44 +265,13 @@ acpi_index_string_exist(struct kobject *kobj, struct attribute *attr, int n)
static ssize_t
acpilabel_show(struct device *dev, struct device_attribute *attr, char *buf)
{
- struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
- acpi_handle handle;
- int length;
-
- handle = ACPI_HANDLE(dev);
-
- if (!handle)
- return -1;
-
- length = dsm_get_label(handle, DEVICE_LABEL_DSM,
- &output, buf, ACPI_ATTR_LABEL_SHOW);
-
- if (length < 1)
- return -1;
-
- return length;
+ return dsm_get_label(dev, buf, ACPI_ATTR_LABEL_SHOW);
}
static ssize_t
acpiindex_show(struct device *dev, struct device_attribute *attr, char *buf)
{
- struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
- acpi_handle handle;
- int length;
-
- handle = ACPI_HANDLE(dev);
-
- if (!handle)
- return -1;
-
- length = dsm_get_label(handle, DEVICE_LABEL_DSM,
- &output, buf, ACPI_ATTR_INDEX_SHOW);
-
- if (length < 0)
- return -1;
-
- return length;
-
+ return dsm_get_label(dev, buf, ACPI_ATTR_INDEX_SHOW);
}
static struct device_attribute acpi_attr_label = {
--
1.7.10.4
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