gbm: Add buffer handling and visuals for fp16 formats

Define and set a new loader cap DRI_LOADER_CAP_FP16, indicating that gbm can
handle fp16 formats.

Signed-off-by: Kevin Strasser <kevin.strasser@intel.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

include/GL/internal/dri_interface.h

@@ -1100,6 +1100,7 @@ enum dri_loader_cap {
     * only BGRA ordering can be exposed.
     */
    DRI_LOADER_CAP_RGBA_ORDERING,
+   DRI_LOADER_CAP_FP16,
 };
 
 struct __DRIdri2LoaderExtensionRec {

src/egl/drivers/dri2/egl_dri2.c

@@ -2422,6 +2422,8 @@ dri2_num_fourcc_format_planes(EGLint format)
    case DRM_FORMAT_ABGR2101010:
    case DRM_FORMAT_RGBA1010102:
    case DRM_FORMAT_BGRA1010102:
+   case DRM_FORMAT_XBGR16161616F:
+   case DRM_FORMAT_ABGR16161616F:
    case DRM_FORMAT_YUYV:
    case DRM_FORMAT_YVYU:
    case DRM_FORMAT_UYVY:

src/gbm/backends/dri/gbm_dri.c

@@ -110,6 +110,18 @@ dri_get_buffers_with_format(__DRIdrawable * driDrawable,
                                    count, out_count, surf->dri_private);
 }
 
+static unsigned
+dri_get_capability(void *loaderPrivate, enum dri_loader_cap cap)
+{
+   /* Note: loaderPrivate is _EGLDisplay* */
+   switch (cap) {
+   case DRI_LOADER_CAP_FP16:
+      return 1;
+   default:
+      return 0;
+   }
+}
+
 static int
 image_get_buffers(__DRIdrawable *driDrawable,
                   unsigned int format,
@@ -207,11 +219,12 @@ static const __DRIimageLookupExtension image_lookup_extension = {
 };
 
 static const __DRIdri2LoaderExtension dri2_loader_extension = {
-   .base = { __DRI_DRI2_LOADER, 3 },
+   .base = { __DRI_DRI2_LOADER, 4 },
 
    .getBuffers              = dri_get_buffers,
    .flushFrontBuffer        = dri_flush_front_buffer,
    .getBuffersWithFormat    = dri_get_buffers_with_format,
+   .getCapability           = dri_get_capability,
 };
 
 static const __DRIimageLoaderExtension image_loader_extension = {
@@ -536,6 +549,18 @@ static const struct gbm_dri_visual gbm_dri_visuals_table[] = {
      { 0, 10, 20, 30 },
      { 10, 10, 10, 2 },
    },
+   {
+     GBM_FORMAT_XBGR16161616F, __DRI_IMAGE_FORMAT_XBGR16161616F,
+     { 0, 16, 32, -1 },
+     { 16, 16, 16, 0 },
+     true,
+   },
+   {
+     GBM_FORMAT_ABGR16161616F, __DRI_IMAGE_FORMAT_ABGR16161616F,
+     { 0, 16, 32, 48 },
+     { 16, 16, 16, 16 },
+     true,
+   },
 };
 
 static int

src/gbm/main/gbm.c

@@ -271,6 +271,9 @@ gbm_bo_get_bpp(struct gbm_bo *bo)
       case GBM_FORMAT_RGBA1010102:
       case GBM_FORMAT_BGRA1010102:
          return 32;
+      case GBM_FORMAT_XBGR16161616F:
+      case GBM_FORMAT_ABGR16161616F:
+         return 64;
    }
 }
 

src/gbm/main/gbm.h

@@ -150,6 +150,15 @@ enum gbm_bo_format {
 #define GBM_FORMAT_RGBA1010102	__gbm_fourcc_code('R', 'A', '3', '0') /* [31:0] R:G:B:A 10:10:10:2 little endian */
 #define GBM_FORMAT_BGRA1010102	__gbm_fourcc_code('B', 'A', '3', '0') /* [31:0] B:G:R:A 10:10:10:2 little endian */
 
+/*
+ * Floating point 64bpp RGB
+ * IEEE 754-2008 binary16 half-precision float
+ * [15:0] sign:exponent:mantissa 1:5:10
+ */
+#define GBM_FORMAT_XBGR16161616F __gbm_fourcc_code('X', 'B', '4', 'H') /* [63:0] x:B:G:R 16:16:16:16 little endian */
+
+#define GBM_FORMAT_ABGR16161616F __gbm_fourcc_code('A', 'B', '4', 'H') /* [63:0] A:B:G:R 16:16:16:16 little endian */
+
 /* packed YCbCr */
 #define GBM_FORMAT_YUYV		__gbm_fourcc_code('Y', 'U', 'Y', 'V') /* [31:0] Cr0:Y1:Cb0:Y0 8:8:8:8 little endian */
 #define GBM_FORMAT_YVYU		__gbm_fourcc_code('Y', 'V', 'Y', 'U') /* [31:0] Cb0:Y1:Cr0:Y0 8:8:8:8 little endian */