virgl: Introduce virgl_staging_mgr

Add a manager for the staging buffer used in virgl. The staging manager
is heavily inspired by u_upload_mgr, but is simpler and is a better fit
for virgl's purposes. In particular, the staging manager:

* Allows concurrent staging allocations.
* Calls the virgl winsys directly to create and map resources, avoiding
  unnecessarily going through gallium resources and transfers.

olv: make virgl_staging_alloc_buffer return a bool

Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>

src/gallium/drivers/virgl/Makefile.sources

@@ -12,6 +12,8 @@ C_SOURCES := \
 	virgl_resource.h \
 	virgl_screen.c \
 	virgl_screen.h \
+	virgl_staging_mgr.c \
+	virgl_staging_mgr.h \
 	virgl_streamout.c \
 	virgl_texture.c \
 	virgl_tgsi.c \

src/gallium/drivers/virgl/meson.build

@@ -25,6 +25,7 @@ files_libvirgl = files(
   'virgl_query.c',
   'virgl_resource.c',
   'virgl_screen.c',
+  'virgl_staging_mgr.c',
   'virgl_streamout.c',
   'virgl_transfer_queue.c',
   'virgl_texture.c',

src/gallium/drivers/virgl/virgl_staging_mgr.c

@@ -0,0 +1,135 @@
+/*
+ * Copyright 2009 VMware, Inc.
+ * Copyright 2019 Collabora Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * on the rights to use, copy, modify, merge, publish, distribute, sub
+ * license, and/or sell copies of the Software, and to permit persons to whom
+ * the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include "pipe/p_defines.h"
+#include "util/u_inlines.h"
+#include "pipe/p_context.h"
+#include "util/u_memory.h"
+#include "util/u_math.h"
+
+#include "virgl_staging_mgr.h"
+#include "virgl_resource.h"
+
+static bool
+virgl_staging_alloc_buffer(struct virgl_staging_mgr *staging, unsigned min_size)
+{
+   struct virgl_winsys *vws = staging->vws;
+   unsigned size;
+
+   /* Release the old buffer, if present:
+    */
+   vws->resource_reference(vws, &staging->hw_res, NULL);
+
+   /* Allocate a new one:
+    */
+   size = align(MAX2(staging->default_size, min_size), 4096);
+
+   staging->hw_res = vws->resource_create(vws,
+                                          PIPE_BUFFER,
+                                          PIPE_FORMAT_R8_UNORM,
+                                          VIRGL_BIND_STAGING,
+                                          size,  /* width */
+                                          1,     /* height */
+                                          1,     /* depth */
+                                          1,     /* array_size */
+                                          0,     /* last_level */
+                                          0,     /* nr_samples */
+                                          size); /* size */
+   if (staging->hw_res == NULL)
+      return false;
+
+   staging->map = vws->resource_map(vws, staging->hw_res);
+   if (staging->map == NULL) {
+      vws->resource_reference(vws, &staging->hw_res, NULL);
+      return false;
+   }
+
+   staging->offset = 0;
+   staging->size = size;
+
+   return true;
+}
+
+void
+virgl_staging_init(struct virgl_staging_mgr *staging, struct pipe_context *pipe,
+                   unsigned default_size)
+{
+   memset(staging, 0, sizeof(*staging));
+
+   staging->vws = virgl_screen(pipe->screen)->vws;
+   staging->default_size = default_size;
+}
+
+void
+virgl_staging_destroy(struct virgl_staging_mgr *staging)
+{
+   struct virgl_winsys *vws = staging->vws;
+   vws->resource_reference(vws, &staging->hw_res, NULL);
+}
+
+bool
+virgl_staging_alloc(struct virgl_staging_mgr *staging,
+                    unsigned size,
+                    unsigned alignment,
+                    unsigned *out_offset,
+                    struct virgl_hw_res **outbuf,
+                    void **ptr)
+{
+   struct virgl_winsys *vws = staging->vws;
+   unsigned offset = align(staging->offset, alignment);
+
+   assert(out_offset);
+   assert(outbuf);
+   assert(ptr);
+   assert(size);
+
+   /* Make sure we have enough space in the staging buffer
+    * for the sub-allocation.
+    */
+   if (offset + size > staging->size) {
+      if (unlikely(!virgl_staging_alloc_buffer(staging, size))) {
+         *out_offset = ~0;
+         vws->resource_reference(vws, outbuf, NULL);
+         *ptr = NULL;
+         return false;
+      }
+
+      offset = 0;
+   }
+
+   assert(staging->size);
+   assert(staging->hw_res);
+   assert(staging->map);
+   assert(offset < staging->size);
+   assert(offset + size <= staging->size);
+
+   /* Emit the return values: */
+   *ptr = staging->map + offset;
+   vws->resource_reference(vws, outbuf, staging->hw_res);
+   *out_offset = offset;
+
+   staging->offset = offset + size;
+
+   return true;
+}

src/gallium/drivers/virgl/virgl_staging_mgr.h

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2009 VMware, Inc.
+ * Copyright 2019 Collabora Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * on the rights to use, copy, modify, merge, publish, distribute, sub
+ * license, and/or sell copies of the Software, and to permit persons to whom
+ * the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/* virgl staging buffer manager, heavily inspired by u_upload_mgr. */
+
+#ifndef VIRGL_STAGING_MGR_H
+#define VIRGL_STAGING_MGR_H
+
+struct pipe_context;
+struct virgl_hw_res;
+struct virgl_winsys;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct virgl_staging_mgr {
+   struct virgl_winsys *vws;
+   unsigned default_size;  /* Minimum size of the staging buffer, in bytes. */
+   struct virgl_hw_res *hw_res;   /* Staging buffer hw_res. */
+   unsigned size;   /* Current staging buffer size. */
+   uint8_t *map;    /* Pointer to the mapped staging buffer. */
+   unsigned offset; /* Offset pointing at the first unused buffer byte. */
+};
+
+/**
+ * Init the staging manager.
+ *
+ * \param staging       Pointer to the staging manager to initialize.
+ * \param pipe          Pipe driver.
+ * \param default_size  Minimum size of the staging buffer, in bytes.
+ */
+void
+virgl_staging_init(struct virgl_staging_mgr *staging, struct pipe_context *pipe,
+                   unsigned default_size);
+
+/**
+ * Destroy the staging manager.
+ */
+void
+virgl_staging_destroy(struct virgl_staging_mgr *staging);
+
+/**
+ * Sub-allocate new memory from the staging buffer.
+ *
+ * The returned pointer to the buffer references the internal staging buffer.
+ *
+ * The returned pointer to staging buffer memory is guaranteed to be valid
+ * for as long as the returned buffer is still referenced.
+ *
+ * \param staging          Staging manager
+ * \param size             Size of the allocation.
+ * \param alignment        Alignment of the suballocation within the buffer.
+ * \param out_offset       Pointer to where the new buffer offset will be returned.
+ * \param outbuf           Pointer to where the staging buffer will be returned.
+ * \param ptr              Pointer to the allocated memory that is returned.
+ * \return                 Whether the allocation is successful.
+ */
+bool
+virgl_staging_alloc(struct virgl_staging_mgr *staging,
+                    unsigned size,
+                    unsigned alignment,
+                    unsigned *out_offset,
+                    struct virgl_hw_res **outbuf,
+                    void **ptr);
+
+#ifdef __cplusplus
+} // extern "C" {
+#endif
+
+#endif