drm/amdgpu/powerplay: get SMC FW size to a flexible way

Get SMC fw size before backdoor loading instead of giving an
certain value, as it may different for different ASIC.
Signed-off-by: Likun Gao <Likun.Gao@amd.com>
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Kevin Wang <kevin1.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/powerplay/inc/smu_v11_0.h

@@ -37,7 +37,6 @@
 #define MP0_SRAM			0x03900000
 #define MP1_Public			0x03b00000
 #define MP1_SRAM			0x03c00004
-#define MP1_SMC_SIZE		0x40000
 
 /* address block */
 #define smnMP1_FIRMWARE_FLAGS		0x3010024

drivers/gpu/drm/amd/powerplay/smu_v11_0.c

@@ -201,13 +201,15 @@ int smu_v11_0_load_microcode(struct smu_context *smu)
 	const struct smc_firmware_header_v1_0 *hdr;
 	uint32_t addr_start = MP1_SRAM;
 	uint32_t i;
+	uint32_t smc_fw_size;
 	uint32_t mp1_fw_flags;
 
 	hdr = (const struct smc_firmware_header_v1_0 *) adev->pm.fw->data;
 	src = (const uint32_t *)(adev->pm.fw->data +
 		le32_to_cpu(hdr->header.ucode_array_offset_bytes));
+	smc_fw_size = hdr->header.ucode_size_bytes;
 
-	for (i = 1; i < MP1_SMC_SIZE/4 - 1; i++) {
+	for (i = 1; i < smc_fw_size/4 - 1; i++) {
 		WREG32_PCIE(addr_start, src[i]);
 		addr_start += 4;
 	}