drm/amd/amdgpu: export vbios information (v2)

Allows userspace components to fetch information
from the vbios image.

v2: agd: fix warning

Reviewed-by: Edward O'Callaghan <[e-mail]>
Signed-off-by: Evan Quan <[e-mail]>
Reviewed-by: Alex Deucher <[e-mail]>
Reviewed-by: Christian Koenig <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

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

···
 		return copy_to_user(out, &vce_clk_table,
 				    min((size_t)size, sizeof(vce_clk_table))) ? -EFAULT : 0;
 	}
+	case AMDGPU_INFO_VBIOS: {
+		uint32_t bios_size = adev->bios_size;
+
+		switch (info->vbios_info.type) {
+		case AMDGPU_INFO_VBIOS_SIZE:
+			return copy_to_user(out, &bios_size,
+					min((size_t)size, sizeof(bios_size)))
+					? -EFAULT : 0;
+		case AMDGPU_INFO_VBIOS_IMAGE: {
+			uint8_t *bios;
+			uint32_t bios_offset = info->vbios_info.offset;
+
+			if (bios_offset >= bios_size)
+				return -EINVAL;
+
+			bios = adev->bios + bios_offset;
+			return copy_to_user(out, bios,
+					    min((size_t)size, (size_t)(bios_size - bios_offset)))
+					? -EFAULT : 0;
+		}
+		default:
+			DRM_DEBUG_KMS("Invalid request %d\n",
+					info->vbios_info.type);
+			return -EINVAL;
+		}
+	}
 	default:
 		DRM_DEBUG_KMS("Invalid request %d\n", info->query);
 		return -EINVAL;

include/uapi/drm/amdgpu_drm.h

···
 #define AMDGPU_INFO_MEMORY			0x19
 /* Query vce clock table */
 #define AMDGPU_INFO_VCE_CLOCK_TABLE		0x1A
+/* Query vbios related information */
+#define AMDGPU_INFO_VBIOS			0x1B
+	/* Subquery id: Query vbios size */
+	#define AMDGPU_INFO_VBIOS_SIZE		0x1
+	/* Subquery id: Query vbios image */
+	#define AMDGPU_INFO_VBIOS_IMAGE		0x2
 
 #define AMDGPU_INFO_MMR_SE_INDEX_SHIFT	0
 #define AMDGPU_INFO_MMR_SE_INDEX_MASK	0xff
···
 		} read_mmr_reg;
 
 		struct drm_amdgpu_query_fw query_fw;
+
+		struct {
+			__u32 type;
+			__u32 offset;
+		} vbios_info;
 	};
 };