libdrm part of the render-node patch series

libdrm part of the render-node patch series

[Ilija Hadzic]

The following two patches add libdrm support for render node
manipulation. The first patch adds the functions for render
node creation and removal that an application can call.
The second patch add two small test utilities that allow
render node creation and removal from shell.

For example, this will create a render node with one CRTC, one
encoder and one connector and use object IDs 10, 16, and 17 for
CRTC, encoder and connector respectively 

<libdrm>/tests/render_nodes/render_node_add -c 1 -e 1 -p 1 -l 10,16,17

To find out object IDs for your GPU you can use <libdrm>/tests/modeprint
test utility.

Kernel will check that the IDs are valid (i.e. that CRTC is really a CRTC)
and not in use by some other render node, but it will not (yet) check
the interdependency (e.g., if a given encoder can go with a given connector).
The latter is still on TODO list.

To remove the render node use

<libdrm>/tests/render_nodes/render_node_rm -m <minor>

To specify the render node with no display resources (typically for
GPGPU ise), just type render_node_add without arguments.

By default, the test utility will use /dev/dri/controlD64 device, which
is a control node for the first GPU in the system. That can be changed
with -n <node> parameter but the node must be a control node (can't
issue the ioctl through other render node or through the physical card
node).

At this point, the biggest missing thing is the ability to specify the
render node in xorg.conf. So to test this for multiseat-X use case
you still need a hack from Dave Airlie [1] and you need to setup
an environment variable to point X to the right render node [2,3,4 
-- customize for your system]

The following is a list of various problems that still need to
be worked out before this becomes stable (help appreciated).
I have not looked into the details so I have no idea what the causes
are nor how they are related to the fact that it's running
on a render node, but I list them here:

* If I start a seat from fbcon, Gnome 3 would sometimes hang up
  (workaround: ssh to the target machine from another machine and
  start a seat from there)
* Native XFCE terminal acts up (typing in it crashes the window
  manager)
* Typing in Gnome terminal, makes input characters leak into
  the running fbcon.
* Sending DPMS event from a seat that uses the render node makes
  the screen go dark and never recover
* Killing the glxgears window sometimes causes the whole
  session to be killed.

Barring the above issues, that clearly need to be fixed before
render-nodes can become generally useful, things seem to be
cranking. I was able to run the session in various desktop managers,
run with desktop effects turned on, play games and run various
OpenGL demos.

Regards,
Ilija

----

[1] http://people.freedesktop.org/~airlied/multiseat/0001-libdrm-add-support-for-an-env-variable-to-override-t.patch
[2] http://people.freedesktop.org/~airlied/multiseat/xorg.conf
[3] http://people.freedesktop.org/~airlied/multiseat/start1
[4] http://people.freedesktop.org/~airlied/multiseat/start2

[PATCH 1/2] libdrm: add functions for render node manipulation

[Ilija Hadzic]

Implement the user-space side of drm_render_node_create
and drm_render_node_remove ioctls. The new functions
are drmCreateRenderNode and drmRemoveRenderNode.

Signed-off-by: Ilija Hadzic <ihadzic@research.bell-labs.com>
---
 include/drm/drm.h      |    2 +
 include/drm/drm_mode.h |   16 +++++++++++++
 xf86drm.c              |   56 ++++++++++++++++++++++++++++++++++++++++++++++++
 xf86drm.h              |    5 ++++
 4 files changed, 79 insertions(+), 0 deletions(-)

diff --git a/include/drm/drm.h b/include/drm/drm.h
index 8adb9d5..d5bb126 100644
--- a/include/drm/drm.h
+++ b/include/drm/drm.h
@@ -639,6 +639,8 @@ struct drm_get_cap {
 #define DRM_IOCTL_GEM_FLINK		DRM_IOWR(0x0a, struct drm_gem_flink)
 #define DRM_IOCTL_GEM_OPEN		DRM_IOWR(0x0b, struct drm_gem_open)
 #define DRM_IOCTL_GET_CAP		DRM_IOWR(0x0c, struct drm_get_cap)
+#define DRM_IOCTL_RENDER_NODE_CREATE    DRM_IOWR(0x0d, struct drm_render_node_create)
+#define DRM_IOCTL_RENDER_NODE_REMOVE    DRM_IOWR(0x0e, struct drm_render_node_remove)
 
 #define DRM_IOCTL_SET_UNIQUE		DRM_IOW( 0x10, struct drm_unique)
 #define DRM_IOCTL_AUTH_MAGIC		DRM_IOW( 0x11, struct drm_auth)
diff --git a/include/drm/drm_mode.h b/include/drm/drm_mode.h
index f36c61a..2998629 100644
--- a/include/drm/drm_mode.h
+++ b/include/drm/drm_mode.h
@@ -437,4 +437,20 @@ struct drm_mode_destroy_dumb {
 	__u32 handle;
 };
 
+/*
+ * render node create and remove functions
+ * if crtc/encoders/connectors all == 0 then gpgpu node
+ */
+struct drm_render_node_create {
+	__u32 node_minor_id;
+	__u32 num_crtc;
+	__u32 num_encoder;
+	__u32 num_connector;
+	__u64 id_list_ptr;
+};
+
+struct drm_render_node_remove {
+	__u32 node_minor_id;
+};
+
 #endif
diff --git a/xf86drm.c b/xf86drm.c
index 7def2b3..af43332 100644
--- a/xf86drm.c
+++ b/xf86drm.c
@@ -2552,3 +2552,59 @@ char *drmGetDeviceNameFromFd(int fd)
 out:
 	return strdup(name);
 }
+
+/**
+ * Create a new render node.
+ *
+ * \param fd file descriptor.
+ * \param minor pointer where to put the minor of the new node.
+ * \param num_crtc number of CRTCs to assign to the new node.
+ * \param num_encoder number of encoders to assign to the new node.
+ * \param num_connector number of connectors to assign to the new node.
+ * \param id_list list of CRTC/encoder/connector IDs.
+ *
+ * \return zero on success, or a negative value on failure.
+ *
+ * \internal
+ * Issues an ioctl to the kernel to create a new render node
+ * and popluates the variable pointed by *minor with the new minor
+ * device number.
+ */
+int drmCreateRenderNode(int fd, int *minor,
+			int num_crtc, int num_encoder, int num_connector,
+			uint32_t *id_list)
+{
+	struct drm_render_node_create node;
+	int r;
+
+	node.num_crtc = num_crtc;
+	node.num_encoder = num_encoder;
+	node.num_connector = num_connector;
+	node.id_list_ptr = (uint64_t)(unsigned long)id_list;
+	r = drmIoctl(fd, DRM_IOCTL_RENDER_NODE_CREATE, &node);
+	if (!r)
+		*minor = node.node_minor_id;
+	return r;
+}
+
+/**
+ * Remove the render node.
+ *
+ * \param fd file descriptor.
+ * \param minor minor device number to remove.
+ *
+ * \return zero on success, or a negative value on failure.
+ *
+ * \internal
+ * Issues an ioctl to the kernel to remove a new render node
+ * identified by the file descriptor and the minor device number.
+ */
+int drmRemoveRenderNode(int fd, int minor)
+{
+	struct drm_render_node_remove node;
+	int r;
+
+	node.node_minor_id = minor;
+	r = drmIoctl(fd, DRM_IOCTL_RENDER_NODE_REMOVE, &node);
+	return r;
+}
diff --git a/xf86drm.h b/xf86drm.h
index 76eb94e..bd5b11e 100644
--- a/xf86drm.h
+++ b/xf86drm.h
@@ -701,6 +701,11 @@ extern void drmMsg(const char *format, ...);
 extern int drmSetMaster(int fd);
 extern int drmDropMaster(int fd);
 
+extern int drmCreateRenderNode(int fd, int *minor,
+			       int num_crtc, int num_encoder, int num_connector,
+			       uint32_t *id_list);
+extern int drmRemoveRenderNode(int fd, int minor);
+
 #define DRM_EVENT_CONTEXT_VERSION 2
 
 typedef struct _drmEventContext {
-- 
1.7.8.5

[PATCH 2/2] tests: add render_node tests

[Ilija Hadzic]

Add two simple programs (render_node_add and render_node_rm)
that can be used to add and remove render nodes from a shell
command or a script.

Signed-off-by: Ilija Hadzic <ihadzic@research.bell-labs.com>
---
 .gitignore                           |    2 +
 configure.ac                         |    1 +
 tests/Makefile.am                    |    2 +-
 tests/render_nodes/Makefile.am       |   16 ++++
 tests/render_nodes/render_node_add.c |  152 ++++++++++++++++++++++++++++++++++
 tests/render_nodes/render_node_rm.c  |   88 ++++++++++++++++++++
 6 files changed, 260 insertions(+), 1 deletions(-)
 create mode 100644 tests/render_nodes/Makefile.am
 create mode 100644 tests/render_nodes/render_node_add.c
 create mode 100644 tests/render_nodes/render_node_rm.c

diff --git a/.gitignore b/.gitignore
index 243457e..3d2afe8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -76,3 +76,5 @@ tests/modeprint/modeprint
 tests/modetest/modetest
 tests/kmstest/kmstest
 tests/vbltest/vbltest
+tests/render_nodes/render_node_add
+tests/render_nodes/render_node_rm
diff --git a/configure.ac b/configure.ac
index 1ba7eba..797a4bf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -308,6 +308,7 @@ AC_CONFIG_FILES([
 	tests/kmstest/Makefile
 	tests/radeon/Makefile
 	tests/vbltest/Makefile
+	tests/render_nodes/Makefile
 	include/Makefile
 	include/drm/Makefile
 	libdrm.pc])
diff --git a/tests/Makefile.am b/tests/Makefile.am
index a3a59bd..f916a38 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -10,7 +10,7 @@ check_PROGRAMS = \
 	dristat \
 	drmstat
 
-SUBDIRS = modeprint
+SUBDIRS = modeprint render_nodes
 
 if HAVE_LIBKMS
 SUBDIRS += kmstest modetest
diff --git a/tests/render_nodes/Makefile.am b/tests/render_nodes/Makefile.am
new file mode 100644
index 0000000..133d792
--- /dev/null
+++ b/tests/render_nodes/Makefile.am
@@ -0,0 +1,16 @@
+AM_CFLAGS = \
+	-I$(top_srcdir)/include/drm \
+	-I$(top_srcdir)
+
+noinst_PROGRAMS = \
+	render_node_add render_node_rm
+
+render_node_add_SOURCES = \
+	render_node_add.c
+render_node_add_LDADD = \
+	$(top_builddir)/libdrm.la
+
+render_node_rm_SOURCES = \
+	render_node_rm.c
+render_node_rm_LDADD = \
+	$(top_builddir)/libdrm.la
diff --git a/tests/render_nodes/render_node_add.c b/tests/render_nodes/render_node_add.c
new file mode 100644
index 0000000..62c9a84
--- /dev/null
+++ b/tests/render_nodes/render_node_add.c
@@ -0,0 +1,152 @@
+/*
+ * Copyright 2012 Alcatel-Lucent, Inc.
+ *
+ * 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 COPYRIGHT HOLDER(S) AND/OR ITS 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.
+ *
+ * Authors:
+ *    Ilija Hadzic <ihadzic@research.bell-labs.com>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h>
+#include <xf86drm.h>
+
+#include "config.h"
+
+void print_usage()
+{
+	fprintf(stderr, "Render Node Add\n");
+	fprintf(stderr, "Usage:\n");
+	fprintf(stderr, "\trender-node-add -? | [-n control_node_path] "
+		"[-c num_crtc] [-e num_encoders] [-p num_connectors] "
+		"[-l id_list]\n");
+}
+
+int parse_id_list(char *in_list, uint32_t *out_list, int list_size)
+{
+	int i;
+	char *list_elem;
+
+	if (!in_list)
+		return 0;
+	list_elem = strtok(in_list, ",");
+	out_list[0] = strtol(list_elem, NULL, 0);
+	for (i = 1; list_elem && i < list_size; i++) {
+		list_elem = strtok(NULL, ",");
+		if (!list_elem)
+			break;
+		out_list[i] = strtol(list_elem, NULL, 0);
+	}
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	int r;
+	int i;
+	int minor;
+	int fd;
+	int num_crtc, num_encoder, num_connector;
+	uint32_t *id_list;
+	char *id_list_arg;
+	char *control_node;
+	int id_list_size;
+
+	num_crtc = 0;
+	num_encoder = 0;
+	num_connector = 0;
+	id_list = NULL;
+	id_list_arg = NULL;
+	control_node = NULL;
+	while ((r = getopt(argc, argv, "n:c:e:p:l:?")) != -1) {
+		switch (r) {
+		case 'n':
+			control_node = optarg;
+			break;
+		case 'c':
+			num_crtc = strtol(optarg, NULL, 0);
+			if (num_crtc < 0)
+				num_crtc = 0;
+			break;
+		case 'e':
+			num_encoder = strtol(optarg, NULL, 0);
+			if (num_encoder < 0)
+				num_encoder = 0;
+			break;
+		case 'p':
+			num_connector = strtol(optarg, NULL, 0);
+			if (num_connector < 0)
+				num_connector = 0;
+			break;
+		case 'l':
+			id_list_arg = optarg;
+			break;
+		case '?':
+		default:
+			print_usage();
+			return 0;
+		}
+	}
+	id_list_size = num_crtc + num_encoder + num_connector;
+	if (id_list_size) {
+		int s;
+
+		id_list = calloc(id_list_size, sizeof(uint32_t));
+		if (!id_list) {
+			perror(argv[0]);
+			exit(EXIT_FAILURE);
+		}
+		s = parse_id_list(id_list_arg, id_list, id_list_size);
+		if (s) {
+			fprintf(stderr, "id_list parse error\n");
+			free(id_list);
+			exit(EXIT_FAILURE);
+		}
+	}
+	if (!control_node)
+		control_node = "/dev/dri/controlD64";
+	printf("control_node = %s\n", control_node);
+	fd = open(control_node, 0);
+	if (fd == -1) {
+		perror(argv[0]);
+		exit(EXIT_FAILURE);
+	}
+	printf("id_list = ");
+	for (i = 0; i < id_list_size; i++)
+		printf("%d ", id_list[i]);
+	printf("\n");
+	r = drmCreateRenderNode(fd, &minor, num_crtc, num_encoder,
+				num_connector, id_list);
+	if (r) {
+		free(id_list);
+		close(fd);
+		perror(argv[0]);
+		exit(EXIT_FAILURE);
+	}
+	printf("minor = %d\n", minor);
+	free(id_list);
+	close(fd);
+	return 0;
+}
diff --git a/tests/render_nodes/render_node_rm.c b/tests/render_nodes/render_node_rm.c
new file mode 100644
index 0000000..f792ad9
--- /dev/null
+++ b/tests/render_nodes/render_node_rm.c
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2012 Alcatel-Lucent, Inc.
+ *
+ * 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 COPYRIGHT HOLDER(S) AND/OR ITS 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.
+ *
+ * Authors:
+ *    Ilija Hadzic <ihadzic@research.bell-labs.com>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <xf86drm.h>
+
+#include "config.h"
+
+void print_usage()
+{
+	fprintf(stderr, "Render Node Remove\n");
+	fprintf(stderr, "Usage:\n");
+	fprintf(stderr, "\trender-node-rm -? | ");
+	fprintf(stderr, "[-n control_node_path] -m <minor>\n");
+}
+
+int main(int argc, char **argv)
+{
+	int r;
+	char *control_node;
+	int minor;
+	int fd;
+
+	control_node = NULL;
+	minor = -1;
+	while ((r = getopt(argc, argv, "n:m:?")) != -1) {
+		switch (r) {
+		case 'n':
+			control_node = optarg;
+			break;
+		case 'm':
+			minor = strtol(optarg, NULL, 0);
+			break;
+		case '?':
+		default:
+			print_usage();
+			return 0;
+		}
+	}
+	if (minor < 0) {
+		fprintf(stderr, "missing or invalid minor number\n");
+		exit(EXIT_FAILURE);
+	}
+	if (!control_node)
+		control_node = "/dev/dri/controlD64";
+	printf("control_node = %s\n", control_node);
+	fd = open(control_node, 0);
+	if (fd == -1) {
+		perror(argv[0]);
+		exit(EXIT_FAILURE);
+	}
+	printf("minor = %d\n", minor);
+	r = drmRemoveRenderNode(fd, minor);
+	close(fd);
+	if (r) {
+		perror(argv[0]);
+		exit(EXIT_FAILURE);
+	}
+	return 0;
+}
-- 
1.7.8.5