drm/amdgpu: Modify comments of vram_start/end

Modify the comment to reflect the fact that, if
use GART for vram address translation for vmid0,
[vram_start, vram_end] will be placed inside SYSVM
aperture, together with GART.

Signed-off-by: Oak Zeng <Oak.Zeng@amd.com>
Reviewed-by: Christian Konig <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
index 11c6977c0b350ed1826e0f9cf9c1084c741af6ba..f1a21e1106106d9f491c41d603dd60499b4834fd 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
@@ -190,10 +190,13 @@ struct amdgpu_gmc {
        u64                     gart_end;
        /* Frame buffer aperture of this GPU device. Different from
         * fb_start (see below), this only covers the local GPU device.
-        * Driver get fb_start from MC_VM_FB_LOCATION_BASE (set by vbios)
-        * and calculate vram_start of this local device by adding an
-        * offset inside the XGMI hive.
-        * Under VMID0, logical address == MC address
+        * If use FB aperture to access FB, driver get fb_start from
+        * MC_VM_FB_LOCATION_BASE (set by vbios) and calculate vram_start
+        * of this local device by adding an offset inside the XGMI hive.
+        * If use GART table for VMID0 FB access, driver finds a hole in
+        * VMID0's virtual address space to place the SYSVM aperture inside
+        * which the first part is vram and the second part is gart (covering
+        * sram)
         */
        u64                     vram_start;
        u64                     vram_end;