freedreno: one screen to rule them all

Similar to fee0686c21, but in this case to
ensure that drm_gralloc and libGLES_mesa are sharing a single screen.

Bumps libdrm_freedreno version dependency, as it requires the new
fd_device_fd() API.

Signed-off-by: Rob Clark <robclark@freedesktop.org>

configure.ac

@@ -74,7 +74,7 @@ LIBDRM_AMDGPU_REQUIRED=2.4.63
 LIBDRM_INTEL_REQUIRED=2.4.61
 LIBDRM_NVVIEUX_REQUIRED=2.4.33
 LIBDRM_NOUVEAU_REQUIRED=2.4.62
-LIBDRM_FREEDRENO_REQUIRED=2.4.64
+LIBDRM_FREEDRENO_REQUIRED=2.4.65
 DRI2PROTO_REQUIRED=2.6
 DRI3PROTO_REQUIRED=1.0
 PRESENTPROTO_REQUIRED=1.0

src/gallium/drivers/freedreno/freedreno_screen.c

@@ -483,6 +483,7 @@ fd_screen_create(struct fd_device *dev)
 	pscreen = &screen->base;
 
 	screen->dev = dev;
+	screen->refcnt = 1;
 
 	// maybe this should be in context?
 	screen->pipe = fd_pipe_new(screen->dev, FD_PIPE_3D);

src/gallium/drivers/freedreno/freedreno_screen.h

@@ -42,6 +42,16 @@ struct fd_bo;
 struct fd_screen {
 	struct pipe_screen base;
 
+	/* it would be tempting to use pipe_reference here, but that
+	 * really doesn't work well if it isn't the first member of
+	 * the struct, so not quite so awesome to be adding refcnting
+	 * further down the inheritance hierarchy:
+	 */
+	int refcnt;
+
+	/* place for winsys to stash it's own stuff: */
+	void *winsys_priv;
+
 	uint32_t gmemsize_bytes;
 	uint32_t device_id;
 	uint32_t gpu_id;         /* 220, 305, etc */

src/gallium/targets/dri/dri.sym

@@ -5,6 +5,7 @@
 		nouveau_drm_screen_create;
 		radeon_drm_winsys_create;
 		amdgpu_winsys_create;
+		fd_drm_screen_create;
 	local:
 		*;
 };

src/gallium/winsys/freedreno/drm/freedreno_drm_winsys.c

@@ -1,18 +1,127 @@
+/* -*- mode: C; c-file-style: "k&r"; tab-width 4; indent-tabs-mode: t; -*- */
+
+/*
+ * Copyright (C) 2012 Rob Clark <robclark@freedesktop.org>
+ *
+ * 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
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * 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 NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS 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.
+ *
+ * Authors:
+ *    Rob Clark <robclark@freedesktop.org>
+ */
+
+#include <sys/stat.h>
+
 #include "pipe/p_context.h"
 #include "pipe/p_state.h"
 #include "util/u_format.h"
 #include "util/u_memory.h"
 #include "util/u_inlines.h"
+#include "util/u_hash_table.h"
+#include "os/os_thread.h"
 
 #include "freedreno_drm_public.h"
 
 #include "freedreno/freedreno_screen.h"
 
+static struct util_hash_table *fd_tab = NULL;
+
+pipe_static_mutex(fd_screen_mutex);
+
+static void
+fd_drm_screen_destroy(struct pipe_screen *pscreen)
+{
+	struct fd_screen *screen = fd_screen(pscreen);
+	boolean destroy;
+
+	pipe_mutex_lock(fd_screen_mutex);
+	destroy = --screen->refcnt == 0;
+	if (destroy) {
+		int fd = fd_device_fd(screen->dev);
+		util_hash_table_remove(fd_tab, intptr_to_pointer(fd));
+	}
+	pipe_mutex_unlock(fd_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 *
 fd_drm_screen_create(int fd)
 {
-	struct fd_device *dev = fd_device_new_dup(fd);
-	if (!dev)
-		return NULL;
-	return fd_screen_create(dev);
+	struct pipe_screen *pscreen = NULL;
+
+	pipe_mutex_lock(fd_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) {
+		fd_screen(pscreen)->refcnt++;
+	} else {
+		struct fd_device *dev = fd_device_new_dup(fd);
+		if (!dev)
+			goto unlock;
+
+		pscreen = fd_screen_create(dev);
+		if (pscreen) {
+			int fd = fd_device_fd(dev);
+
+			util_hash_table_set(fd_tab, intptr_to_pointer(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():
+			 */
+			fd_screen(pscreen)->winsys_priv = pscreen->destroy;
+			pscreen->destroy = fd_drm_screen_destroy;
+		}
+	}
+
+unlock:
+	pipe_mutex_unlock(fd_screen_mutex);
+	return pscreen;
 }