gstreamer/gst-libs/gst/vaapi/gstvaapidisplay_drm.c
Gwenole Beauchesne 71053228b3 display: make cache maintenance really MT-safe.
Make sure to initialize one GstVaapiDisplay at a time, even in threaded
environments. This makes sure the display cache is also consistent
during the whole display creation process. In the former implementation,
there were risks that display cache got updated in another thread.
2014-05-21 19:59:52 +02:00

412 lines
12 KiB
C

/*
* gstvaapidisplay_drm.c - VA/DRM display abstraction
*
* Copyright (C) 2012-2013 Intel Corporation
* Author: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1
* of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA
*/
/**
* SECTION:gstvaapidisplay_drm
* @short_description: VA/DRM display abstraction
*/
#include "sysdeps.h"
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <libudev.h>
#include <xf86drm.h>
#include <va/va_drm.h>
#include "gstvaapiutils.h"
#include "gstvaapidisplay_priv.h"
#include "gstvaapidisplay_drm.h"
#include "gstvaapidisplay_drm_priv.h"
#define DEBUG 1
#include "gstvaapidebug.h"
static const guint g_display_types = 1U << GST_VAAPI_DISPLAY_TYPE_DRM;
/* Get default device path. Actually, the first match in the DRM subsystem */
static const gchar *
get_default_device_path (GstVaapiDisplay * display)
{
GstVaapiDisplayDRMPrivate *const priv =
GST_VAAPI_DISPLAY_DRM_PRIVATE (display);
const gchar *syspath, *devpath;
struct udev *udev = NULL;
struct udev_device *device, *parent;
struct udev_enumerate *e = NULL;
struct udev_list_entry *l;
int fd;
if (!priv->device_path_default) {
udev = udev_new ();
if (!udev)
goto end;
e = udev_enumerate_new (udev);
if (!e)
goto end;
udev_enumerate_add_match_subsystem (e, "drm");
udev_enumerate_scan_devices (e);
udev_list_entry_foreach (l, udev_enumerate_get_list_entry (e)) {
syspath = udev_list_entry_get_name (l);
device = udev_device_new_from_syspath (udev, syspath);
parent = udev_device_get_parent (device);
if (strcmp (udev_device_get_subsystem (parent), "pci") != 0) {
udev_device_unref (device);
continue;
}
devpath = udev_device_get_devnode (device);
fd = open (devpath, O_RDWR | O_CLOEXEC);
if (fd < 0) {
udev_device_unref (device);
continue;
}
priv->device_path_default = g_strdup (devpath);
close (fd);
udev_device_unref (device);
break;
}
end:
if (e)
udev_enumerate_unref (e);
if (udev)
udev_unref (udev);
}
return priv->device_path_default;
}
/* Reconstruct a device path without our prefix */
static const gchar *
get_device_path (GstVaapiDisplay * display)
{
GstVaapiDisplayDRMPrivate *const priv =
GST_VAAPI_DISPLAY_DRM_PRIVATE (display);
const gchar *device_path = priv->device_path;
if (!device_path || *device_path == '\0')
return NULL;
return device_path;
}
/* Mangle device path with our prefix */
static gboolean
set_device_path (GstVaapiDisplay * display, const gchar * device_path)
{
GstVaapiDisplayDRMPrivate *const priv =
GST_VAAPI_DISPLAY_DRM_PRIVATE (display);
g_free (priv->device_path);
priv->device_path = NULL;
if (!device_path) {
device_path = get_default_device_path (display);
if (!device_path)
return FALSE;
}
priv->device_path = g_strdup (device_path);
return priv->device_path != NULL;
}
/* Set device path from file descriptor */
static gboolean
set_device_path_from_fd (GstVaapiDisplay * display, gint drm_device)
{
GstVaapiDisplayDRMPrivate *const priv =
GST_VAAPI_DISPLAY_DRM_PRIVATE (display);
const gchar *busid, *path, *str;
gsize busid_length, path_length;
struct udev *udev = NULL;
struct udev_device *device;
struct udev_enumerate *e = NULL;
struct udev_list_entry *l;
gboolean success = FALSE;
g_free (priv->device_path);
priv->device_path = NULL;
if (drm_device < 0)
goto end;
busid = drmGetBusid (drm_device);
if (!busid)
goto end;
if (strncmp (busid, "pci:", 4) != 0)
goto end;
busid += 4;
busid_length = strlen (busid);
udev = udev_new ();
if (!udev)
goto end;
e = udev_enumerate_new (udev);
if (!e)
goto end;
udev_enumerate_add_match_subsystem (e, "drm");
udev_enumerate_scan_devices (e);
udev_list_entry_foreach (l, udev_enumerate_get_list_entry (e)) {
path = udev_list_entry_get_name (l);
str = strstr (path, busid);
if (!str || str <= path || str[-1] != '/')
continue;
path_length = strlen (path);
if (str + busid_length >= path + path_length)
continue;
if (strncmp (&str[busid_length], "/drm/card", 9) != 0)
continue;
device = udev_device_new_from_syspath (udev, path);
if (!device)
continue;
path = udev_device_get_devnode (device);
priv->device_path = g_strdup (path);
udev_device_unref (device);
break;
}
success = TRUE;
end:
if (e)
udev_enumerate_unref (e);
if (udev)
udev_unref (udev);
return success;
}
static gboolean
gst_vaapi_display_drm_bind_display (GstVaapiDisplay * display,
gpointer native_display)
{
GstVaapiDisplayDRMPrivate *const priv =
GST_VAAPI_DISPLAY_DRM_PRIVATE (display);
priv->drm_device = GPOINTER_TO_INT (native_display);
priv->use_foreign_display = TRUE;
if (!set_device_path_from_fd (display, priv->drm_device))
return FALSE;
return TRUE;
}
static gboolean
gst_vaapi_display_drm_open_display (GstVaapiDisplay * display,
const gchar * name)
{
GstVaapiDisplayDRMPrivate *const priv =
GST_VAAPI_DISPLAY_DRM_PRIVATE (display);
GstVaapiDisplayCache *const cache = GST_VAAPI_DISPLAY_GET_CACHE (display);
const GstVaapiDisplayInfo *info;
if (!set_device_path (display, name))
return FALSE;
info = gst_vaapi_display_cache_lookup_by_name (cache, priv->device_path,
GST_VAAPI_DISPLAY_TYPES (display));
if (info) {
priv->drm_device = GPOINTER_TO_INT (info->native_display);
priv->use_foreign_display = TRUE;
} else {
priv->drm_device = open (get_device_path (display), O_RDWR | O_CLOEXEC);
if (priv->drm_device < 0)
return FALSE;
priv->use_foreign_display = FALSE;
}
return TRUE;
}
static void
gst_vaapi_display_drm_close_display (GstVaapiDisplay * display)
{
GstVaapiDisplayDRMPrivate *const priv =
GST_VAAPI_DISPLAY_DRM_PRIVATE (display);
if (priv->drm_device >= 0) {
if (!priv->use_foreign_display)
close (priv->drm_device);
priv->drm_device = -1;
}
if (priv->device_path) {
g_free (priv->device_path);
priv->device_path = NULL;
}
if (priv->device_path_default) {
g_free (priv->device_path_default);
priv->device_path_default = NULL;
}
}
static gboolean
gst_vaapi_display_drm_get_display_info (GstVaapiDisplay * display,
GstVaapiDisplayInfo * info)
{
GstVaapiDisplayDRMPrivate *const priv =
GST_VAAPI_DISPLAY_DRM_PRIVATE (display);
GstVaapiDisplayCache *const cache = GST_VAAPI_DISPLAY_GET_CACHE (display);
const GstVaapiDisplayInfo *cached_info;
/* Return any cached info even if child has its own VA display */
cached_info = gst_vaapi_display_cache_lookup_by_native_display (cache,
GINT_TO_POINTER (priv->drm_device), GST_VAAPI_DISPLAY_TYPES (display));
if (cached_info) {
*info = *cached_info;
return TRUE;
}
/* Otherwise, create VA display if there is none already */
info->native_display = GINT_TO_POINTER (priv->drm_device);
info->display_name = priv->device_path;
if (!info->va_display) {
info->va_display = vaGetDisplayDRM (priv->drm_device);
if (!info->va_display)
return FALSE;
info->display_type = GST_VAAPI_DISPLAY_TYPE_DRM;
}
return TRUE;
}
static void
gst_vaapi_display_drm_init (GstVaapiDisplay * display)
{
GstVaapiDisplayDRMPrivate *const priv =
GST_VAAPI_DISPLAY_DRM_PRIVATE (display);
priv->drm_device = -1;
}
static void
gst_vaapi_display_drm_class_init (GstVaapiDisplayDRMClass * klass)
{
GstVaapiMiniObjectClass *const object_class =
GST_VAAPI_MINI_OBJECT_CLASS (klass);
GstVaapiDisplayClass *const dpy_class = GST_VAAPI_DISPLAY_CLASS (klass);
gst_vaapi_display_class_init (&klass->parent_class);
object_class->size = sizeof (GstVaapiDisplayDRM);
dpy_class->display_types = g_display_types;
dpy_class->init = gst_vaapi_display_drm_init;
dpy_class->bind_display = gst_vaapi_display_drm_bind_display;
dpy_class->open_display = gst_vaapi_display_drm_open_display;
dpy_class->close_display = gst_vaapi_display_drm_close_display;
dpy_class->get_display = gst_vaapi_display_drm_get_display_info;
}
static inline const GstVaapiDisplayClass *
gst_vaapi_display_drm_class (void)
{
static GstVaapiDisplayDRMClass g_class;
static gsize g_class_init = FALSE;
if (g_once_init_enter (&g_class_init)) {
gst_vaapi_display_drm_class_init (&g_class);
g_once_init_leave (&g_class_init, TRUE);
}
return GST_VAAPI_DISPLAY_CLASS (&g_class);
}
/**
* gst_vaapi_display_drm_new:
* @device_path: the DRM device path
*
* Opens an DRM file descriptor using @device_path and returns a newly
* allocated #GstVaapiDisplay object. The DRM display will be cloed
* when the reference count of the object reaches zero.
*
* If @device_path is NULL, the DRM device path will be automatically
* determined as the first positive match in the list of available DRM
* devices.
*
* Return value: a newly allocated #GstVaapiDisplay object
*/
GstVaapiDisplay *
gst_vaapi_display_drm_new (const gchar * device_path)
{
return gst_vaapi_display_new (gst_vaapi_display_drm_class (),
GST_VAAPI_DISPLAY_INIT_FROM_DISPLAY_NAME, (gpointer) device_path);
}
/**
* gst_vaapi_display_drm_new_with_device:
* @device: an open DRM device (file descriptor)
*
* Creates a #GstVaapiDisplay based on the open DRM @device. The
* caller still owns the device file descriptor and must call close()
* when all #GstVaapiDisplay references are released. Doing so too
* early can yield undefined behaviour.
*
* Return value: a newly allocated #GstVaapiDisplay object
*/
GstVaapiDisplay *
gst_vaapi_display_drm_new_with_device (gint device)
{
g_return_val_if_fail (device >= 0, NULL);
return gst_vaapi_display_new (gst_vaapi_display_drm_class (),
GST_VAAPI_DISPLAY_INIT_FROM_NATIVE_DISPLAY, GINT_TO_POINTER (device));
}
/**
* gst_vaapi_display_drm_get_device:
* @display: a #GstVaapiDisplayDRM
*
* Returns the underlying DRM device file descriptor that was created
* by gst_vaapi_display_drm_new() or that was bound from
* gst_vaapi_display_drm_new_with_device().
*
* Return value: the DRM file descriptor attached to @display
*/
gint
gst_vaapi_display_drm_get_device (GstVaapiDisplayDRM * display)
{
g_return_val_if_fail (GST_VAAPI_IS_DISPLAY_DRM (display), -1);
return GST_VAAPI_DISPLAY_DRM_DEVICE (display);
}
/**
* gst_vaapi_display_drm_get_device_path:
* @display: a #GstVaapiDisplayDRM
*
* Returns the underlying DRM device path name was created by
* gst_vaapi_display_drm_new() or that was bound from
* gst_vaapi_display_drm_new_with_device().
*
* Note: the #GstVaapiDisplayDRM object owns the resulting string, so
* it shall not be deallocated.
*
* Return value: the DRM device path name attached to @display
*/
const gchar *
gst_vaapi_display_drm_get_device_path (GstVaapiDisplayDRM * display)
{
g_return_val_if_fail (GST_VAAPI_IS_DISPLAY_DRM (display), NULL);
return get_device_path (GST_VAAPI_DISPLAY_CAST (display));
}