drm/amdgpu: Reserve discovery TMR only if needed

For legacy SOCs, discovery binary is sideloaded. Instead of checking for
binary blob, use a flag to determine if discovery region needs to be
reserved.

Signed-off-by: Lijo Lazar <[e-mail]>
Reviewed-by: Alex Deucher <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c

···
 	else
 		vram_size <<= 20;
 
+	/*
+	 * If in VRAM, discovery TMR is marked for reservation. If it is in system mem,
+	 * then it is not required to be reserved.
+	 */
 	if (sz_valid) {
 		uint64_t pos = vram_size - DISCOVERY_TMR_OFFSET;
 		amdgpu_device_vram_access(adev, pos, (uint32_t *)binary,
 					  adev->discovery.size, false);
+		adev->discovery.reserve_tmr = true;
 	} else {
 		ret = amdgpu_discovery_read_binary_from_sysmem(adev, binary);
 	}
···
 
 static const char *amdgpu_discovery_get_fw_name(struct amdgpu_device *adev)
 {
-	if (amdgpu_discovery == 2)
+	if (amdgpu_discovery == 2) {
+		/* Assume there is valid discovery TMR in VRAM even if binary is sideloaded */
+		adev->discovery.reserve_tmr = true;
 		return "amdgpu/ip_discovery.bin";
+	}
 
 	switch (adev->asic_type) {
 	case CHIP_VEGA10:

drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.h

···
 	struct ip_discovery_top *ip_top;
 	uint32_t size;
 	uint8_t *bin;
+	bool reserve_tmr;
 };
 
 void amdgpu_discovery_fini(struct amdgpu_device *adev);

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c

···
 		ctx->init = PSP_MEM_TRAIN_RESERVE_SUCCESS;
 	}
 
-	if (!adev->gmc.is_app_apu) {
-		ret = amdgpu_bo_create_kernel_at(
-			adev, adev->gmc.real_vram_size - reserve_size,
-			reserve_size, &adev->mman.fw_reserved_memory, NULL);
-		if (ret) {
-			dev_err(adev->dev, "alloc tmr failed(%d)!\n", ret);
-			amdgpu_bo_free_kernel(&adev->mman.fw_reserved_memory,
-					      NULL, NULL);
-			return ret;
-		}
-	} else {
-		DRM_DEBUG_DRIVER("backdoor fw loading path for PSP TMR, no reservation needed\n");
+	ret = amdgpu_bo_create_kernel_at(
+		adev, adev->gmc.real_vram_size - reserve_size, reserve_size,
+		&adev->mman.fw_reserved_memory, NULL);
+	if (ret) {
+		dev_err(adev->dev, "alloc tmr failed(%d)!\n", ret);
+		amdgpu_bo_free_kernel(&adev->mman.fw_reserved_memory, NULL,
+				      NULL);
+		return ret;
 	}
 
 	return 0;
···
 	 * If IP discovery enabled, a block of memory should be
 	 * reserved for IP discovey.
 	 */
-	if (adev->discovery.bin) {
+	if (adev->discovery.reserve_tmr) {
 		r = amdgpu_ttm_reserve_tmr(adev);
 		if (r)
 			return r;