1 files changed, 47 insertions, 18 deletions

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowacpi.c b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowacpi.c
index 06572f8ce914..f9c427559538 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowacpi.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowacpi.c
@@ -22,22 +22,39 @@
  */
 #include "priv.h"
 
-#if defined(CONFIG_ACPI) && defined(CONFIG_X86)
-int nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len);
-bool nouveau_acpi_rom_supported(struct device *);
-#else
-static inline bool
-nouveau_acpi_rom_supported(struct device *dev)
+static int
+acpi_read_bios(acpi_handle rom_handle, u8 *bios, u32 offset, u32 length)
 {
-	return false;
-}
+#if defined(CONFIG_ACPI) && defined(CONFIG_X86)
+	acpi_status status;
+	union acpi_object rom_arg_elements[2], *obj;
+	struct acpi_object_list rom_arg;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL};
 
-static inline int
-nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len)
-{
+	rom_arg.count = 2;
+	rom_arg.pointer = &rom_arg_elements[0];
+
+	rom_arg_elements[0].type = ACPI_TYPE_INTEGER;
+	rom_arg_elements[0].integer.value = offset;
+
+	rom_arg_elements[1].type = ACPI_TYPE_INTEGER;
+	rom_arg_elements[1].integer.value = length;
+
+	status = acpi_evaluate_object(rom_handle, NULL, &rom_arg, &buffer);
+	if (ACPI_FAILURE(status)) {
+		pr_info("failed to evaluate ROM got %s\n",
+			acpi_format_exception(status));
+		return -ENODEV;
+	}
+	obj = (union acpi_object *)buffer.pointer;
+	length = min(length, obj->buffer.length);
+	memcpy(bios+offset, obj->buffer.pointer, length);
+	kfree(buffer.pointer);
+	return length;
+#else
 	return -EINVAL;
-}
 #endif
+}
 
 /* This version of the shadow function disobeys the ACPI spec and tries
  * to fetch in units of more than 4KiB at a time.  This is a LOT faster
@@ -51,7 +68,7 @@ acpi_read_fast(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
 	u32 fetch = limit - start;
 
 	if (nvbios_extend(bios, limit) >= 0) {
-		int ret = nouveau_acpi_get_bios_chunk(bios->data, start, fetch);
+		int ret = acpi_read_bios(data, bios->data, start, fetch);
 		if (ret == fetch)
 			return fetch;
 	}
@@ -73,9 +90,8 @@ acpi_read_slow(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
 
 	if (nvbios_extend(bios, limit) >= 0) {
 		while (start + fetch < limit) {
-			int ret = nouveau_acpi_get_bios_chunk(bios->data,
-							      start + fetch,
-							      0x1000);
+			int ret = acpi_read_bios(data, bios->data,
+						 start + fetch, 0x1000);
 			if (ret != 0x1000)
 				break;
 			fetch += 0x1000;
@@ -88,9 +104,22 @@ acpi_read_slow(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
 static void *
 acpi_init(struct nvkm_bios *bios, const char *name)
 {
-	if (!nouveau_acpi_rom_supported(bios->subdev.device->dev))
+#if defined(CONFIG_ACPI) && defined(CONFIG_X86)
+	acpi_status status;
+	acpi_handle dhandle, rom_handle;
+
+	dhandle = ACPI_HANDLE(bios->subdev.device->dev);
+	if (!dhandle)
 		return ERR_PTR(-ENODEV);
-	return NULL;
+
+	status = acpi_get_handle(dhandle, "_ROM", &rom_handle);
+	if (ACPI_FAILURE(status))
+		return ERR_PTR(-ENODEV);
+
+	return rom_handle;
+#else
+	return ERR_PTR(-ENODEV);
+#endif
 }
 
 const struct nvbios_source