drm/amdgpu: add an interface to get gfx constants from atombios

Fetch the values from atom rather than hardcoding them in the
driver.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -684,6 +684,36 @@ int amdgpu_atombios_get_clock_info(struct amdgpu_device *adev)
 	return ret;
 }
 
+union gfx_info {
+	ATOM_GFX_INFO_V2_1 info;
+};
+
+int amdgpu_atombios_get_gfx_info(struct amdgpu_device *adev)
+{
+	struct amdgpu_mode_info *mode_info = &adev->mode_info;
+	int index = GetIndexIntoMasterTable(DATA, GFX_Info);
+	uint8_t frev, crev;
+	uint16_t data_offset;
+	int ret = -EINVAL;
+
+	if (amdgpu_atom_parse_data_header(mode_info->atom_context, index, NULL,
+				   &frev, &crev, &data_offset)) {
+		union gfx_info *gfx_info = (union gfx_info *)
+			(mode_info->atom_context->bios + data_offset);
+
+		adev->gfx.config.max_shader_engines = gfx_info->info.max_shader_engines;
+		adev->gfx.config.max_tile_pipes = gfx_info->info.max_tile_pipes;
+		adev->gfx.config.max_cu_per_sh = gfx_info->info.max_cu_per_sh;
+		adev->gfx.config.max_sh_per_se = gfx_info->info.max_sh_per_se;
+		adev->gfx.config.max_backends_per_se = gfx_info->info.max_backends_per_se;
+		adev->gfx.config.max_texture_channel_caches =
+			gfx_info->info.max_texture_channel_caches;
+
+		ret = 0;
+	}
+	return ret;
+}
+
 union igp_info {
 	struct _ATOM_INTEGRATED_SYSTEM_INFO info;
 	struct _ATOM_INTEGRATED_SYSTEM_INFO_V2 info_2;

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

@@ -144,6 +144,8 @@ bool amdgpu_atombios_get_connector_info_from_object_table(struct amdgpu_device *
 
 int amdgpu_atombios_get_clock_info(struct amdgpu_device *adev);
 
+int amdgpu_atombios_get_gfx_info(struct amdgpu_device *adev);
+
 bool amdgpu_atombios_get_asic_ss_info(struct amdgpu_device *adev,
 				      struct amdgpu_atom_ss *ss,
 				      int id, u32 clock);