drm/amdgpu: Reserve shared memory on VRAM for SR-IOV

SR-IOV need to reserve a piece of shared VRAM at the exact place
to exchange data betweem PF and VF. The start address and size of
the shared mem are passed to guest through VBIOS structure
VRAM_UsageByFirmware.

VRAM_UsageByFirmware is a general feature in VBIOS, it indicates
that VBIOS need to reserve a piece of memory on the VRAM.

Because the mem address is specified. Reserve it early in
amdgpu_ttm_init to make sure that it can monoplize the space.

Signed-off-by: Horace Chen <horace.chen@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 15a2857..1f68a14 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1255,6 +1255,15 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
 	/* Change the size here instead of the init above so only lpfn is affected */
 	amdgpu_ttm_set_active_vram_size(adev, adev->mc.visible_vram_size);
 
+	/*
+	 *The reserved vram for firmware must be pinned to the specified
+	 *place on the VRAM, so reserve it early.
+	 */
+	r = amdgpu_fw_reserve_vram_init(adev);
+	if (r) {
+		return r;
+	}
+
 	r = amdgpu_bo_create_kernel(adev, adev->mc.stolen_size, PAGE_SIZE,
 				    AMDGPU_GEM_DOMAIN_VRAM,
 				    &adev->stolen_vga_memory,