From 1d0fcef732832432aee47cb75bf4a2cb3107be64 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Thu, 19 Dec 2013 20:38:13 +0800 Subject: [PATCH] ACPI / PCI: replace open-coded _DSM code with helper functions 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 Signed-off-by: Rafael J. Wysocki --- 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 f6e01a500d79..f12dcd1dc208 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 = { -- 2.39.2