gallium: add sparse buffer interface and capability

v2:
- explain the resource_commit interface in more detail

Reviewed-by: Marek Olšák <marek.olsak@amd.com>

src/gallium/docs/source/context.rst

@@ -618,6 +618,31 @@ are set.
 
 
 
+.. _resource_commit:
+
+resource_commit
+%%%%%%%%%%%%%%%
+
+This function changes the commit state of a part of a sparse resource. Sparse
+resources are created by setting the ``PIPE_RESOURCE_FLAG_SPARSE`` flag when
+calling ``resource_create``. Initially, sparse resources only reserve a virtual
+memory region that is not backed by memory (i.e., it is uncommitted). The
+``resource_commit`` function can be called to commit or uncommit parts (or all)
+of a resource. The driver manages the underlying backing memory.
+
+The contents of newly committed memory regions are undefined. Calling this
+function to commit an already committed memory region is allowed and leaves its
+content unchanged. Similarly, calling this function to uncommit an already
+uncommitted memory region is allowed.
+
+For buffers, the given box must be aligned to multiples of
+``PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE``. As an exception to this rule, if the size
+of the buffer is not a multiple of the page size, changing the commit state of
+the last (partial) page requires a box that ends at the end of the buffer
+(i.e., box->x + box->width == buffer->width0).
+
+
+
 .. _pipe_transfer:
 
 PIPE_TRANSFER

src/gallium/docs/source/screen.rst

@@ -381,6 +381,9 @@ The integer capabilities:
   PIPE_POLYGON_MODE_FILL_RECTANGLE mode is supported for
   ``pipe_rasterizer_state::fill_front`` and
   ``pipe_rasterizer_state::fill_back``.
+* ``PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE``: The page size of sparse buffers in
+  bytes, or 0 if sparse buffers are not supported. The page size must be at
+  most 64KB.
 
 
 .. _pipe_capf:

src/gallium/drivers/etnaviv/etnaviv_screen.c

@@ -247,6 +247,7 @@ etna_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_TGSI_TEX_TXF_LZ:
    case PIPE_CAP_TGSI_CLOCK:
    case PIPE_CAP_POLYGON_MODE_FILL_RECTANGLE:
+   case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
       return 0;
 
    /* Stream output. */

src/gallium/drivers/freedreno/freedreno_screen.c

@@ -304,6 +304,7 @@ fd_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
 	case PIPE_CAP_TGSI_TEX_TXF_LZ:
 	case PIPE_CAP_TGSI_CLOCK:
 	case PIPE_CAP_POLYGON_MODE_FILL_RECTANGLE:
+	case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
 		return 0;
 
 	case PIPE_CAP_MAX_VIEWPORTS:

src/gallium/drivers/i915/i915_screen.c

@@ -303,6 +303,7 @@ i915_get_param(struct pipe_screen *screen, enum pipe_cap cap)
    case PIPE_CAP_INT64_DIVMOD:
    case PIPE_CAP_TGSI_TEX_TXF_LZ:
    case PIPE_CAP_TGSI_CLOCK:
+   case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
       return 0;
 
    case PIPE_CAP_MAX_VIEWPORTS:

src/gallium/drivers/llvmpipe/lp_screen.c

@@ -349,6 +349,7 @@ llvmpipe_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_TGSI_MUL_ZERO_WINS:
    case PIPE_CAP_TGSI_CLOCK:
    case PIPE_CAP_POLYGON_MODE_FILL_RECTANGLE:
+   case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
       return 0;
    }
    /* should only get here on unhandled cases */

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

@@ -213,6 +213,7 @@ nv30_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_TGSI_TEX_TXF_LZ:
    case PIPE_CAP_TGSI_CLOCK:
    case PIPE_CAP_POLYGON_MODE_FILL_RECTANGLE:
+   case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
       return 0;
 
    case PIPE_CAP_VENDOR_ID:

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

@@ -265,6 +265,7 @@ nv50_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_INT64_DIVMOD:
    case PIPE_CAP_TGSI_CLOCK:
    case PIPE_CAP_POLYGON_MODE_FILL_RECTANGLE:
+   case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
       return 0;
 
    case PIPE_CAP_VENDOR_ID:

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

@@ -288,6 +288,7 @@ nvc0_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_GLSL_OPTIMIZE_CONSERVATIVELY:
    case PIPE_CAP_INT64_DIVMOD:
    case PIPE_CAP_TGSI_CLOCK:
+   case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
       return 0;
 
    case PIPE_CAP_VENDOR_ID:

src/gallium/drivers/r300/r300_screen.c

@@ -235,6 +235,7 @@ static int r300_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
         case PIPE_CAP_TGSI_TEX_TXF_LZ:
         case PIPE_CAP_TGSI_CLOCK:
         case PIPE_CAP_POLYGON_MODE_FILL_RECTANGLE:
+        case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
             return 0;
 
         /* SWTCL-only features. */

src/gallium/drivers/r600/r600_pipe.c

@@ -383,6 +383,7 @@ static int r600_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
 	case PIPE_CAP_TGSI_TEX_TXF_LZ:
 	case PIPE_CAP_TGSI_CLOCK:
 	case PIPE_CAP_POLYGON_MODE_FILL_RECTANGLE:
+	case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
 		return 0;
 
 	case PIPE_CAP_DOUBLES:

src/gallium/drivers/radeonsi/si_pipe.c

@@ -493,6 +493,7 @@ static int si_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
 	case PIPE_CAP_TGSI_MUL_ZERO_WINS:
 	case PIPE_CAP_UMA:
 	case PIPE_CAP_POLYGON_MODE_FILL_RECTANGLE:
+	case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
 		return 0;
 
 	case PIPE_CAP_QUERY_BUFFER_OBJECT:

src/gallium/drivers/softpipe/sp_screen.c

@@ -299,6 +299,7 @@ softpipe_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_TGSI_MUL_ZERO_WINS:
    case PIPE_CAP_TGSI_CLOCK:
    case PIPE_CAP_POLYGON_MODE_FILL_RECTANGLE:
+   case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
       return 0;
    case PIPE_CAP_SHADER_BUFFER_OFFSET_ALIGNMENT:
       return 4;

src/gallium/drivers/svga/svga_screen.c

@@ -429,6 +429,7 @@ svga_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_TGSI_TEX_TXF_LZ:
    case PIPE_CAP_TGSI_CLOCK:
    case PIPE_CAP_POLYGON_MODE_FILL_RECTANGLE:
+   case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
       return 0;
    }
 

src/gallium/drivers/swr/swr_screen.cpp

@@ -321,6 +321,7 @@ swr_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_TGSI_TEX_TXF_LZ:
    case PIPE_CAP_TGSI_CLOCK:
    case PIPE_CAP_POLYGON_MODE_FILL_RECTANGLE:
+   case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
       return 0;
 
    case PIPE_CAP_VENDOR_ID:

src/gallium/drivers/vc4/vc4_screen.c

@@ -249,6 +249,7 @@ vc4_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
         case PIPE_CAP_TGSI_TEX_TXF_LZ:
         case PIPE_CAP_TGSI_CLOCK:
         case PIPE_CAP_POLYGON_MODE_FILL_RECTANGLE:
+        case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
                 return 0;
 
                 /* Stream output. */

src/gallium/drivers/virgl/virgl_screen.c

@@ -258,6 +258,7 @@ virgl_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_TGSI_TEX_TXF_LZ:
    case PIPE_CAP_TGSI_CLOCK:
    case PIPE_CAP_POLYGON_MODE_FILL_RECTANGLE:
+   case PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE:
       return 0;
    case PIPE_CAP_VENDOR_ID:
       return 0x1af4;

src/gallium/include/pipe/p_context.h

@@ -584,6 +584,19 @@ struct pipe_context {
     */
    void (*memory_barrier)(struct pipe_context *, unsigned flags);
 
+   /**
+    * Change the commitment status of a part of the given resource, which must
+    * have been created with the PIPE_RESOURCE_FLAG_SPARSE bit.
+    *
+    * \param level The texture level whose commitment should be changed.
+    * \param box The region of the resource whose commitment should be changed.
+    * \param commit Whether memory should be committed or un-committed.
+    *
+    * \return false if out of memory, true on success.
+    */
+   bool (*resource_commit)(struct pipe_context *, struct pipe_resource *,
+                           unsigned level, struct pipe_box *box, bool commit);
+
    /**
     * Creates a video codec for a specific video format/profile
     */

src/gallium/include/pipe/p_defines.h

@@ -459,6 +459,7 @@ enum pipe_flush_flags
 #define PIPE_RESOURCE_FLAG_MAP_PERSISTENT (1 << 0)
 #define PIPE_RESOURCE_FLAG_MAP_COHERENT   (1 << 1)
 #define PIPE_RESOURCE_FLAG_TEXTURING_MORE_LIKELY (1 << 2)
+#define PIPE_RESOURCE_FLAG_SPARSE                (1 << 3)
 #define PIPE_RESOURCE_FLAG_DRV_PRIV    (1 << 16) /* driver/winsys private */
 #define PIPE_RESOURCE_FLAG_ST_PRIV     (1 << 24) /* state-tracker/winsys private */
 
@@ -758,6 +759,7 @@ enum pipe_cap
    PIPE_CAP_TGSI_TEX_TXF_LZ,
    PIPE_CAP_TGSI_CLOCK,
    PIPE_CAP_POLYGON_MODE_FILL_RECTANGLE,
+   PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE,
 };
 
 #define PIPE_QUIRK_TEXTURE_BORDER_COLOR_SWIZZLE_NV50 (1 << 0)