gallium: add geometry shader output limits

v2: adjust limits for radeonsi and llvmpipe
v3: add documentation

Cc: "10.1" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Marek Olšák <marek.olsak@amd.com>

src/gallium/docs/source/screen.rst

@@ -176,6 +176,12 @@ The integer capabilities:
   ARB_framebuffer_object is provided.
 * ``PIPE_CAP_TGSI_VS_LAYER``: Whether TGSI_SEMANTIC_LAYER is supported
   as a vertex shader output.
+* ``PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES``: The maximum number of vertices
+  output by a single invocation of a geometry shader.
+* ``PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS``: The maximum number of
+  vertex components output by a single invocation of a geometry shader.
+  This is the product of the number of attribute components per vertex and
+  the number of output vertices.
 
 
 .. _pipe_capf:

src/gallium/drivers/freedreno/freedreno_screen.c

@@ -212,6 +212,11 @@ fd_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
 	case PIPE_CAP_MAX_STREAM_OUTPUT_INTERLEAVED_COMPONENTS:
 		return 0;
 
+	/* Geometry shader output, unsupported. */
+	case PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES:
+	case PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS:
+		return 0;
+
 	/* Texturing. */
 	case PIPE_CAP_MAX_TEXTURE_2D_LEVELS:
 	case PIPE_CAP_MAX_TEXTURE_3D_LEVELS:

src/gallium/drivers/i915/i915_screen.c

@@ -257,6 +257,11 @@ i915_get_param(struct pipe_screen *screen, enum pipe_cap cap)
    case PIPE_CAP_MAX_RENDER_TARGETS:
       return 1;
 
+   /* Geometry shader output, unsupported. */
+   case PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES:
+   case PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS:
+      return 0;
+
    /* Fragment coordinate conventions. */
    case PIPE_CAP_TGSI_FS_COORD_ORIGIN_UPPER_LEFT:
    case PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_HALF_INTEGER:

src/gallium/drivers/ilo/ilo_screen.c

@@ -372,6 +372,9 @@ ilo_get_param(struct pipe_screen *screen, enum pipe_cap param)
       return ILO_MAX_SO_BINDINGS / ILO_MAX_SO_BUFFERS;
    case PIPE_CAP_MAX_STREAM_OUTPUT_INTERLEAVED_COMPONENTS:
       return ILO_MAX_SO_BINDINGS;
+   case PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES:
+   case PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS:
+      return 0;
    case PIPE_CAP_STREAM_OUTPUT_PAUSE_RESUME:
       if (is->dev.gen >= ILO_GEN(7))
          return is->dev.has_gen7_sol_reset;

src/gallium/drivers/llvmpipe/lp_screen.c

@@ -187,6 +187,9 @@ llvmpipe_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_MAX_STREAM_OUTPUT_SEPARATE_COMPONENTS:
    case PIPE_CAP_MAX_STREAM_OUTPUT_INTERLEAVED_COMPONENTS:
       return 16*4;
+   case PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES:
+   case PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS:
+      return 1024;
    case PIPE_CAP_STREAM_OUTPUT_PAUSE_RESUME:
       return 1;
    case PIPE_CAP_TGSI_CAN_COMPACT_CONSTANTS:

src/gallium/drivers/nouveau/nv30/nv30_screen.c

@@ -106,6 +106,8 @@ nv30_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_MAX_TEXEL_OFFSET:
    case PIPE_CAP_MAX_STREAM_OUTPUT_SEPARATE_COMPONENTS:
    case PIPE_CAP_MAX_STREAM_OUTPUT_INTERLEAVED_COMPONENTS:
+   case PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES:
+   case PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS:
    case PIPE_CAP_TGSI_CAN_COMPACT_CONSTANTS:
    case PIPE_CAP_TEXTURE_BARRIER:
    case PIPE_CAP_SEAMLESS_CUBE_MAP:

src/gallium/drivers/nouveau/nv50/nv50_screen.c

@@ -141,6 +141,9 @@ nv50_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_MAX_STREAM_OUTPUT_INTERLEAVED_COMPONENTS:
    case PIPE_CAP_MAX_STREAM_OUTPUT_SEPARATE_COMPONENTS:
       return 64;
+   case PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES:
+   case PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS:
+      return 1024;
    case PIPE_CAP_STREAM_OUTPUT_PAUSE_RESUME:
       return (class_3d >= NVA0_3D_CLASS) ? 1 : 0;
    case PIPE_CAP_BLEND_EQUATION_SEPARATE:

src/gallium/drivers/nouveau/nvc0/nvc0_screen.c

@@ -125,6 +125,9 @@ nvc0_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_MAX_STREAM_OUTPUT_SEPARATE_COMPONENTS:
    case PIPE_CAP_MAX_STREAM_OUTPUT_INTERLEAVED_COMPONENTS:
       return 128;
+   case PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES:
+   case PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS:
+      return 1024;
    case PIPE_CAP_BLEND_EQUATION_SEPARATE:
    case PIPE_CAP_INDEP_BLEND_ENABLE:
    case PIPE_CAP_INDEP_BLEND_FUNC:

src/gallium/drivers/r300/r300_screen.c

@@ -151,6 +151,8 @@ static int r300_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
         case PIPE_CAP_MAX_STREAM_OUTPUT_BUFFERS:
         case PIPE_CAP_MAX_STREAM_OUTPUT_SEPARATE_COMPONENTS:
         case PIPE_CAP_MAX_STREAM_OUTPUT_INTERLEAVED_COMPONENTS:
+        case PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES:
+        case PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS:
         case PIPE_CAP_STREAM_OUTPUT_PAUSE_RESUME:
         case PIPE_CAP_FRAGMENT_COLOR_CLAMPED:
         case PIPE_CAP_QUADS_FOLLOW_PROVOKING_VERTEX_CONVENTION:

src/gallium/drivers/r600/r600_pipe.c

@@ -410,6 +410,12 @@ static int r600_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
 	case PIPE_CAP_MAX_STREAM_OUTPUT_INTERLEAVED_COMPONENTS:
 		return 32*4;
 
+	/* Geometry shader output. */
+	case PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES:
+		return 1024;
+	case PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS:
+		return 16384;
+
 	/* Texturing. */
 	case PIPE_CAP_MAX_TEXTURE_2D_LEVELS:
 	case PIPE_CAP_MAX_TEXTURE_3D_LEVELS:

src/gallium/drivers/radeonsi/si_pipe.c

@@ -299,6 +299,12 @@ static int si_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
 	case PIPE_CAP_MAX_STREAM_OUTPUT_INTERLEAVED_COMPONENTS:
 		return sscreen->b.has_streamout ? 32*4 : 0;
 
+	/* Geometry shader output. */
+	case PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES:
+		return 1024;
+	case PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS:
+		return 4095;
+
 	/* Texturing. */
 	case PIPE_CAP_MAX_TEXTURE_2D_LEVELS:
 	case PIPE_CAP_MAX_TEXTURE_3D_LEVELS:

src/gallium/drivers/softpipe/sp_screen.c

@@ -119,6 +119,9 @@ softpipe_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_MAX_STREAM_OUTPUT_SEPARATE_COMPONENTS:
    case PIPE_CAP_MAX_STREAM_OUTPUT_INTERLEAVED_COMPONENTS:
       return 16*4;
+   case PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES:
+   case PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS:
+      return 0;
    case PIPE_CAP_PRIMITIVE_RESTART:
       return 1;
    case PIPE_CAP_SHADER_STENCIL_EXPORT:

src/gallium/drivers/svga/svga_screen.c

@@ -251,6 +251,8 @@ svga_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_MAX_STREAM_OUTPUT_SEPARATE_COMPONENTS:
    case PIPE_CAP_MAX_STREAM_OUTPUT_INTERLEAVED_COMPONENTS:
    case PIPE_CAP_STREAM_OUTPUT_PAUSE_RESUME:
+   case PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES:
+   case PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS:
    case PIPE_CAP_TGSI_CAN_COMPACT_CONSTANTS:
    case PIPE_CAP_VERTEX_BUFFER_OFFSET_4BYTE_ALIGNED_ONLY:
    case PIPE_CAP_VERTEX_BUFFER_STRIDE_4BYTE_ALIGNED_ONLY:

src/gallium/include/pipe/p_defines.h

@@ -520,7 +520,9 @@ enum pipe_cap {
    PIPE_CAP_MAX_VIEWPORTS = 84,
    PIPE_CAP_ENDIANNESS = 85,
    PIPE_CAP_MIXED_FRAMEBUFFER_SIZES = 86,
-   PIPE_CAP_TGSI_VS_LAYER = 87
+   PIPE_CAP_TGSI_VS_LAYER = 87,
+   PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES = 88,
+   PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS = 89
 };
 
 #define PIPE_QUIRK_TEXTURE_BORDER_COLOR_SWIZZLE_NV50 (1 << 0)

src/mesa/state_tracker/st_extensions.c

@@ -262,6 +262,8 @@ void st_init_limits(struct st_context *st)
    c->Program[MESA_SHADER_VERTEX].MaxOutputComponents = c->MaxVarying * 4;
    c->Program[MESA_SHADER_GEOMETRY].MaxInputComponents = c->MaxVarying * 4;
    c->Program[MESA_SHADER_GEOMETRY].MaxOutputComponents = c->MaxVarying * 4;
+   c->MaxGeometryOutputVertices = screen->get_param(screen, PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES);
+   c->MaxGeometryTotalOutputComponents = screen->get_param(screen, PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS);
 
    c->MinProgramTexelOffset = screen->get_param(screen, PIPE_CAP_MIN_TEXEL_OFFSET);
    c->MaxProgramTexelOffset = screen->get_param(screen, PIPE_CAP_MAX_TEXEL_OFFSET);