gallium: add interface for persistent and coherent buffer mappings

Required for ARB_buffer_storage.

src/gallium/docs/source/context.rst

@@ -520,6 +520,16 @@ invalidates all read caches of the currently-set samplers.
 
 
 
+.. _memory_barrier:
+
+memory_barrier
+%%%%%%%%%%%%%%%
+
+This function flushes caches according to which of the PIPE_BARRIER_* flags
+are set.
+
+
+
 .. _pipe_transfer:
 
 PIPE_TRANSFER
@@ -557,6 +567,18 @@ These flags control the behavior of a transfer object.
   Written ranges will be notified later with :ref:`transfer_flush_region`.
   Cannot be used with ``PIPE_TRANSFER_READ``.
 
+``PIPE_TRANSFER_PERSISTENT``
+  Allows the resource to be used for rendering while mapped.
+  PIPE_RESOURCE_FLAG_MAP_PERSISTENT must be set when creating
+  the resource.
+  If COHERENT is not set, memory_barrier(PIPE_BARRIER_MAPPED_BUFFER)
+  must be called to ensure the device can see what the CPU has written.
+
+``PIPE_TRANSFER_COHERENT``
+  If PERSISTENT is set, this ensures any writes done by the device are
+  immediately visible to the CPU and vice versa.
+  PIPE_RESOURCE_FLAG_MAP_COHERENT must be set when creating
+  the resource.
 
 Compute kernel execution
 ^^^^^^^^^^^^^^^^^^^^^^^^

src/gallium/docs/source/screen.rst

@@ -188,6 +188,9 @@ The integer capabilities:
 * ``PIPE_CAP_TEXTURE_GATHER_SM5``: Whether the texture gather
   hardware implements the SM5 features, component selection,
   shadow comparison, and run-time offsets.
+* ``PIPE_CAP_BUFFER_MAP_PERSISTENT_COHERENT``: Whether
+  PIPE_TRANSFER_PERSISTENT and PIPE_TRANSFER_COHERENT are supported
+  for buffers.
 
 
 .. _pipe_capf:

src/gallium/drivers/trace/tr_context.c

@@ -1489,6 +1489,21 @@ static void trace_context_texture_barrier(struct pipe_context *_context)
 }
 
 
+static void trace_context_memory_barrier(struct pipe_context *_context,
+                                         unsigned flags)
+{
+   struct trace_context *tr_context = trace_context(_context);
+   struct pipe_context *context = tr_context->pipe;
+
+   trace_dump_call_begin("pipe_context", "memory_barrier");
+   trace_dump_arg(ptr, context);
+   trace_dump_arg(uint, flags);
+   trace_dump_call_end();
+
+   context->memory_barrier(context, flags);
+}
+
+
 static const struct debug_named_value rbug_blocker_flags[] = {
    {"before", 1, NULL},
    {"after", 2, NULL},
@@ -1577,6 +1592,7 @@ trace_context_create(struct trace_screen *tr_scr,
    TR_CTX_INIT(clear_depth_stencil);
    TR_CTX_INIT(flush);
    TR_CTX_INIT(texture_barrier);
+   TR_CTX_INIT(memory_barrier);
 
    TR_CTX_INIT(transfer_map);
    TR_CTX_INIT(transfer_unmap);

src/gallium/include/pipe/p_context.h

@@ -406,7 +406,12 @@ struct pipe_context {
     * Flush any pending framebuffer writes and invalidate texture caches.
     */
    void (*texture_barrier)(struct pipe_context *);
-   
+
+   /**
+    * Flush caches according to flags.
+    */
+   void (*memory_barrier)(struct pipe_context *, unsigned flags);
+
    /**
     * Creates a video codec for a specific video format/profile
     */

src/gallium/include/pipe/p_defines.h

@@ -295,8 +295,27 @@ enum pipe_transfer_usage {
     * - D3D10 DDI's D3D10_DDI_MAP_WRITE_DISCARD flag
     * - D3D10's D3D10_MAP_WRITE_DISCARD flag.
     */
-   PIPE_TRANSFER_DISCARD_WHOLE_RESOURCE = (1 << 12)
+   PIPE_TRANSFER_DISCARD_WHOLE_RESOURCE = (1 << 12),
 
+   /**
+    * Allows the resource to be used for rendering while mapped.
+    *
+    * PIPE_RESOURCE_FLAG_MAP_PERSISTENT must be set when creating
+    * the resource.
+    *
+    * If COHERENT is not set, memory_barrier(PIPE_BARRIER_MAPPED_BUFFER)
+    * must be called to ensure the device can see what the CPU has written.
+    */
+   PIPE_TRANSFER_PERSISTENT = (1 << 13),
+
+   /**
+    * If PERSISTENT is set, this ensures any writes done by the device are
+    * immediately visible to the CPU and vice versa.
+    *
+    * PIPE_RESOURCE_FLAG_MAP_COHERENT must be set when creating
+    * the resource.
+    */
+   PIPE_TRANSFER_COHERENT = (1 << 14)
 };
 
 /**
@@ -306,6 +325,11 @@ enum pipe_flush_flags {
    PIPE_FLUSH_END_OF_FRAME = (1 << 0)
 };
 
+/**
+ * Flags for pipe_context::memory_barrier.
+ */
+#define PIPE_BARRIER_MAPPED_BUFFER     (1 << 0)
+
 /*
  * Resource binding flags -- state tracker must specify in advance all
  * the ways a resource might be used.
@@ -352,6 +376,8 @@ enum pipe_flush_flags {
 
 /* Flags for the driver about resource behaviour:
  */
+#define PIPE_RESOURCE_FLAG_MAP_PERSISTENT (1 << 0)
+#define PIPE_RESOURCE_FLAG_MAP_COHERENT   (1 << 1)
 #define PIPE_RESOURCE_FLAG_DRV_PRIV    (1 << 16) /* driver/winsys private */
 #define PIPE_RESOURCE_FLAG_ST_PRIV     (1 << 24) /* state-tracker/winsys private */
 
@@ -524,7 +550,8 @@ enum pipe_cap {
    PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES = 88,
    PIPE_CAP_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS = 89,
    PIPE_CAP_MAX_TEXTURE_GATHER_COMPONENTS = 90,
-   PIPE_CAP_TEXTURE_GATHER_SM5 = 91
+   PIPE_CAP_TEXTURE_GATHER_SM5 = 91,
+   PIPE_CAP_BUFFER_MAP_PERSISTENT_COHERENT = 92
 };
 
 #define PIPE_QUIRK_TEXTURE_BORDER_COLOR_SWIZZLE_NV50 (1 << 0)