drm/amdgpu/atomfirmware: implement vram_width for APUs

Implement support using the new atomfirmware system info table.

Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_atomfirmware.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_atomfirmware.c
index 9ddfe34d12af..a7d65f033883 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atomfirmware.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atomfirmware.c
@@ -95,3 +95,36 @@ int amdgpu_atomfirmware_allocate_fb_scratch(struct amdgpu_device *adev)
         ctx->scratch_size_bytes = usage_bytes;
         return 0;
 }
+
+union igp_info {
+        struct atom_integrated_system_info_v1_11 v11;
+};
+
+/*
+ * Return vram width from integrated system info table, if available,
+ * or 0 if not.
+ */
+int amdgpu_atomfirmware_get_vram_width(struct amdgpu_device *adev)
+{
+        struct amdgpu_mode_info *mode_info = &adev->mode_info;
+        int index = get_index_into_master_table(atom_master_list_of_data_tables_v2_1,
+                                                integratedsysteminfo);
+        u16 data_offset, size;
+        union igp_info *igp_info;
+        u8 frev, crev;
+
+        /* get any igp specific overrides */
+        if (amdgpu_atom_parse_data_header(mode_info->atom_context, index, &size,
+                                   &frev, &crev, &data_offset)) {
+                igp_info = (union igp_info *)
+                        (mode_info->atom_context->bios + data_offset);
+                switch (crev) {
+                case 11:
+                        return igp_info->v11.umachannelnumber * 64;
+                default:
+                        return 0;
+                }
+        }
+
+        return 0;
+}