[Mesa-dev] [PATCH 1/2] virgl: reuse screen when fd is already open
Rob Herring
robh at kernel.org
Fri Jan 29 14:36:28 PST 2016
It is necessary to share the screen between mesa and gralloc to
properly ref count resources. This implements a hash lookup on
the file description to re-use an already created screen. This is
a similar implementation as freedreno and radeon.
Signed-off-by: Rob Herring <robh at kernel.org>
---
src/gallium/auxiliary/target-helpers/drm_helper.h | 7 +-
src/gallium/drivers/virgl/virgl_screen.c | 1 +
src/gallium/drivers/virgl/virgl_screen.h | 6 ++
src/gallium/winsys/virgl/drm/virgl_drm_public.h | 4 +-
src/gallium/winsys/virgl/drm/virgl_drm_winsys.c | 87 +++++++++++++++++++++++
5 files changed, 97 insertions(+), 8 deletions(-)
diff --git a/src/gallium/auxiliary/target-helpers/drm_helper.h b/src/gallium/auxiliary/target-helpers/drm_helper.h
index 332b1cb..90820d3 100644
--- a/src/gallium/auxiliary/target-helpers/drm_helper.h
+++ b/src/gallium/auxiliary/target-helpers/drm_helper.h
@@ -226,14 +226,9 @@ pipe_freedreno_create_screen(int fd)
struct pipe_screen *
pipe_virgl_create_screen(int fd)
{
- struct virgl_winsys *vws;
struct pipe_screen *screen;
- vws = virgl_drm_winsys_create(fd);
- if (!vws)
- return NULL;
-
- screen = virgl_create_screen(vws);
+ screen = virgl_drm_screen_create(fd);
return screen ? debug_screen_wrap(screen) : NULL;
}
diff --git a/src/gallium/drivers/virgl/virgl_screen.c b/src/gallium/drivers/virgl/virgl_screen.c
index fb2e567..d7d8735 100644
--- a/src/gallium/drivers/virgl/virgl_screen.c
+++ b/src/gallium/drivers/virgl/virgl_screen.c
@@ -557,6 +557,7 @@ virgl_create_screen(struct virgl_winsys *vws)
vws->get_caps(vws, &screen->caps);
+ screen->refcnt = 1;
util_format_s3tc_init();
return &screen->base;
diff --git a/src/gallium/drivers/virgl/virgl_screen.h b/src/gallium/drivers/virgl/virgl_screen.h
index 52e72ca..8cac38d 100644
--- a/src/gallium/drivers/virgl/virgl_screen.h
+++ b/src/gallium/drivers/virgl/virgl_screen.h
@@ -28,6 +28,12 @@
struct virgl_screen {
struct pipe_screen base;
+
+ int refcnt;
+
+ /* place for winsys to stash it's own stuff: */
+ void *winsys_priv;
+
struct virgl_winsys *vws;
struct virgl_drm_caps caps;
diff --git a/src/gallium/winsys/virgl/drm/virgl_drm_public.h b/src/gallium/winsys/virgl/drm/virgl_drm_public.h
index be01021..f70f0e5 100644
--- a/src/gallium/winsys/virgl/drm/virgl_drm_public.h
+++ b/src/gallium/winsys/virgl/drm/virgl_drm_public.h
@@ -23,8 +23,8 @@
#ifndef VIRGL_DRM_PUBLIC_H
#define VIRGL_DRM_PUBLIC_H
-struct virgl_winsys;
+struct pipe_screen;
-struct virgl_winsys *virgl_drm_winsys_create(int drmFD);
+struct pipe_screen *virgl_drm_screen_create(int fd);
#endif
diff --git a/src/gallium/winsys/virgl/drm/virgl_drm_winsys.c b/src/gallium/winsys/virgl/drm/virgl_drm_winsys.c
index b5d4435..48a79fa 100644
--- a/src/gallium/winsys/virgl/drm/virgl_drm_winsys.c
+++ b/src/gallium/winsys/virgl/drm/virgl_drm_winsys.c
@@ -25,6 +25,7 @@
#include <fcntl.h>
#include <stdio.h>
#include <sys/ioctl.h>
+#include <sys/stat.h>
#include "os/os_mman.h"
#include "os/os_time.h"
@@ -33,6 +34,8 @@
#include "util/u_hash_table.h"
#include "util/u_inlines.h"
#include "state_tracker/drm_driver.h"
+#include "virgl/virgl_screen.h"
+#include "virgl/virgl_public.h"
#include <xf86drm.h>
#include "virtgpu_drm.h"
@@ -772,3 +775,87 @@ virgl_drm_winsys_create(int drmFD)
return &qdws->base;
}
+
+static struct util_hash_table *fd_tab = NULL;
+pipe_static_mutex(virgl_screen_mutex);
+
+static void
+virgl_drm_screen_destroy(struct pipe_screen *pscreen)
+{
+ struct virgl_screen *screen = virgl_screen(pscreen);
+ boolean destroy;
+
+ pipe_mutex_lock(virgl_screen_mutex);
+ destroy = --screen->refcnt == 0;
+ if (destroy) {
+ int fd = virgl_drm_winsys(screen->vws)->fd;
+ util_hash_table_remove(fd_tab, intptr_to_pointer(fd));
+ }
+ pipe_mutex_unlock(virgl_screen_mutex);
+
+ if (destroy) {
+ pscreen->destroy = screen->winsys_priv;
+ pscreen->destroy(pscreen);
+ }
+}
+
+static unsigned hash_fd(void *key)
+{
+ int fd = pointer_to_intptr(key);
+ struct stat stat;
+ fstat(fd, &stat);
+
+ return stat.st_dev ^ stat.st_ino ^ stat.st_rdev;
+}
+
+static int compare_fd(void *key1, void *key2)
+{
+ int fd1 = pointer_to_intptr(key1);
+ int fd2 = pointer_to_intptr(key2);
+ struct stat stat1, stat2;
+ fstat(fd1, &stat1);
+ fstat(fd2, &stat2);
+
+ return stat1.st_dev != stat2.st_dev ||
+ stat1.st_ino != stat2.st_ino ||
+ stat1.st_rdev != stat2.st_rdev;
+}
+
+struct pipe_screen *
+virgl_drm_screen_create(int fd)
+{
+ struct pipe_screen *pscreen = NULL;
+
+ pipe_mutex_lock(virgl_screen_mutex);
+ if (!fd_tab) {
+ fd_tab = util_hash_table_create(hash_fd, compare_fd);
+ if (!fd_tab)
+ goto unlock;
+ }
+
+ pscreen = util_hash_table_get(fd_tab, intptr_to_pointer(fd));
+ if (pscreen) {
+ virgl_screen(pscreen)->refcnt++;
+ } else {
+ struct virgl_winsys *vws;
+ int dup_fd = dup(fd);
+
+ vws = virgl_drm_winsys_create(dup_fd);
+
+ pscreen = virgl_create_screen(vws);
+ if (pscreen) {
+ util_hash_table_set(fd_tab, intptr_to_pointer(dup_fd), pscreen);
+
+ /* Bit of a hack, to avoid circular linkage dependency,
+ * ie. pipe driver having to call in to winsys, we
+ * override the pipe drivers screen->destroy():
+ */
+ virgl_screen(pscreen)->winsys_priv = pscreen->destroy;
+ pscreen->destroy = virgl_drm_screen_destroy;
+ }
+ }
+
+unlock:
+ pipe_mutex_unlock(virgl_screen_mutex);
+ return pscreen;
+}
--
2.5.0
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