mutter/src/backends/native/meta-drm-buffer-gbm.c
Dor Askayo 56580ea7c9 backends/native: Assume zero rendering time for direct scanout buffers
The previous logic didn't work correctly at least when priority-based
preeption wasn't supported by the DRM driver, such as in the case
of amdgpu. The call to glGetQueryObjecti64v would block on client
work which is already in progress (most likely for the next frame)
and delay notifying the ClutterFrameClock about presentation.

Conveniently, the Wayland transactions mechanism guarantees that all
fences of a dma-buf buffer are signalled before the buffer is
included in a frame, which means that dma-buf buffers are ready for
presentation when being directly scanned-out.

Direct scanout is only supported for dma-buf buffers too, which means
that all buffers going through direct scanout are effectively ready
and require no GPU rendering before presentation.

Assuming zero rendering time for dma-buf buffers going through direct
scanout simplifies the code and removes the need for
glGetQueryObjecti64v, thus avoiding the aforementioned issue where it
could block for longer than expected.

Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/2766
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3080>
2023-06-20 15:32:25 +00:00

405 lines
12 KiB
C

/*
* Copyright (C) 2011 Intel Corporation.
* Copyright (C) 2016 Red Hat
* Copyright (C) 2018 DisplayLink (UK) Ltd.
* Copyright (C) 2018 Canonical Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*
*/
#include "config.h"
#include "backends/native/meta-drm-buffer-gbm.h"
#include <drm_fourcc.h>
#include <errno.h>
#include <gio/gio.h>
#include <xf86drm.h>
#include <xf86drmMode.h>
#include "backends/meta-backend-private.h"
#include "backends/native/meta-cogl-utils.h"
#include "backends/native/meta-device-pool.h"
#include "backends/native/meta-drm-buffer-private.h"
struct _MetaDrmBufferGbm
{
MetaDrmBuffer parent;
struct gbm_surface *surface;
struct gbm_bo *bo;
};
static void
cogl_scanout_iface_init (CoglScanoutInterface *iface);
G_DEFINE_TYPE_WITH_CODE (MetaDrmBufferGbm, meta_drm_buffer_gbm, META_TYPE_DRM_BUFFER,
G_IMPLEMENT_INTERFACE (COGL_TYPE_SCANOUT,
cogl_scanout_iface_init))
struct gbm_bo *
meta_drm_buffer_gbm_get_bo (MetaDrmBufferGbm *buffer_gbm)
{
return buffer_gbm->bo;
}
static int
meta_drm_buffer_gbm_export_fd (MetaDrmBuffer *buffer,
GError **error)
{
MetaDrmBufferGbm *buffer_gbm = META_DRM_BUFFER_GBM (buffer);
int fd;
fd = gbm_bo_get_fd (buffer_gbm->bo);
if (fd == -1)
{
g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno),
"Failed to export buffer fd: %s", g_strerror (errno));
return -1;
}
return fd;
}
static int
meta_drm_buffer_gbm_get_width (MetaDrmBuffer *buffer)
{
MetaDrmBufferGbm *buffer_gbm = META_DRM_BUFFER_GBM (buffer);
return gbm_bo_get_width (buffer_gbm->bo);
}
static int
meta_drm_buffer_gbm_get_height (MetaDrmBuffer *buffer)
{
MetaDrmBufferGbm *buffer_gbm = META_DRM_BUFFER_GBM (buffer);
return gbm_bo_get_height (buffer_gbm->bo);
}
static int
meta_drm_buffer_gbm_get_stride (MetaDrmBuffer *buffer)
{
MetaDrmBufferGbm *buffer_gbm = META_DRM_BUFFER_GBM (buffer);
return gbm_bo_get_stride (buffer_gbm->bo);
}
static int
meta_drm_buffer_gbm_get_bpp (MetaDrmBuffer *buffer)
{
MetaDrmBufferGbm *buffer_gbm = META_DRM_BUFFER_GBM (buffer);
return gbm_bo_get_bpp (buffer_gbm->bo);
}
static uint32_t
meta_drm_buffer_gbm_get_format (MetaDrmBuffer *buffer)
{
MetaDrmBufferGbm *buffer_gbm = META_DRM_BUFFER_GBM (buffer);
return gbm_bo_get_format (buffer_gbm->bo);
}
static int
meta_drm_buffer_gbm_get_offset (MetaDrmBuffer *buffer,
int plane)
{
MetaDrmBufferGbm *buffer_gbm = META_DRM_BUFFER_GBM (buffer);
return gbm_bo_get_offset (buffer_gbm->bo, plane);
}
static uint64_t
meta_drm_buffer_gbm_get_modifier (MetaDrmBuffer *buffer)
{
MetaDrmBufferGbm *buffer_gbm = META_DRM_BUFFER_GBM (buffer);
return gbm_bo_get_modifier (buffer_gbm->bo);
}
static gboolean
meta_drm_buffer_gbm_ensure_fb_id (MetaDrmBuffer *buffer,
GError **error)
{
MetaDrmBufferGbm *buffer_gbm = META_DRM_BUFFER_GBM (buffer);
MetaDrmFbArgs fb_args = { 0, };
struct gbm_bo *bo = buffer_gbm->bo;
if (gbm_bo_get_handle_for_plane (bo, 0).s32 == -1)
{
/* Failed to fetch handle to plane, falling back to old method */
fb_args.strides[0] = gbm_bo_get_stride (bo);
fb_args.handles[0] = gbm_bo_get_handle (bo).u32;
fb_args.offsets[0] = 0;
fb_args.modifiers[0] = DRM_FORMAT_MOD_INVALID;
}
else
{
int i;
for (i = 0; i < gbm_bo_get_plane_count (bo); i++)
{
fb_args.strides[i] = gbm_bo_get_stride_for_plane (bo, i);
fb_args.handles[i] = gbm_bo_get_handle_for_plane (bo, i).u32;
fb_args.offsets[i] = gbm_bo_get_offset (bo, i);
fb_args.modifiers[i] = gbm_bo_get_modifier (bo);
}
}
fb_args.width = gbm_bo_get_width (bo);
fb_args.height = gbm_bo_get_height (bo);
fb_args.format = gbm_bo_get_format (bo);
fb_args.handle = gbm_bo_get_handle (bo).u32;
if (!meta_drm_buffer_do_ensure_fb_id (META_DRM_BUFFER (buffer_gbm),
&fb_args, error))
return FALSE;
return TRUE;
}
static gboolean
lock_front_buffer (MetaDrmBufferGbm *buffer_gbm,
GError **error)
{
buffer_gbm->bo = gbm_surface_lock_front_buffer (buffer_gbm->surface);
if (!buffer_gbm->bo)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
"gbm_surface_lock_front_buffer failed");
return FALSE;
}
return meta_drm_buffer_gbm_ensure_fb_id (META_DRM_BUFFER (buffer_gbm), error);
}
MetaDrmBufferGbm *
meta_drm_buffer_gbm_new_lock_front (MetaDeviceFile *device_file,
struct gbm_surface *gbm_surface,
MetaDrmBufferFlags flags,
GError **error)
{
MetaDrmBufferGbm *buffer_gbm;
buffer_gbm = g_object_new (META_TYPE_DRM_BUFFER_GBM,
"device-file", device_file,
"flags", flags,
NULL);
buffer_gbm->surface = gbm_surface;
if (!lock_front_buffer (buffer_gbm, error))
{
g_object_unref (buffer_gbm);
return NULL;
}
return buffer_gbm;
}
MetaDrmBufferGbm *
meta_drm_buffer_gbm_new_take (MetaDeviceFile *device_file,
struct gbm_bo *bo,
MetaDrmBufferFlags flags,
GError **error)
{
MetaDrmBufferGbm *buffer_gbm;
buffer_gbm = g_object_new (META_TYPE_DRM_BUFFER_GBM,
"device-file", device_file,
"flags", flags,
NULL);
buffer_gbm->bo = bo;
return buffer_gbm;
}
static gboolean
meta_drm_buffer_gbm_blit_to_framebuffer (CoglScanout *scanout,
CoglFramebuffer *framebuffer,
int x,
int y,
GError **error)
{
MetaDrmBufferGbm *buffer_gbm = META_DRM_BUFFER_GBM (scanout);
MetaDrmBuffer *buffer = META_DRM_BUFFER (buffer_gbm);
MetaDeviceFile *device_file = meta_drm_buffer_get_device_file (buffer);
MetaDevicePool *device_pool = meta_device_file_get_pool (device_file);
MetaBackend *backend = meta_device_pool_get_backend (device_pool);
MetaEgl *egl = meta_backend_get_egl (backend);
ClutterBackend *clutter_backend =
meta_backend_get_clutter_backend (backend);
CoglContext *cogl_context =
clutter_backend_get_cogl_context (clutter_backend);
CoglDisplay *cogl_display = cogl_context->display;
CoglRenderer *cogl_renderer = cogl_display->renderer;
CoglRendererEGL *cogl_renderer_egl = cogl_renderer->winsys;
EGLDisplay egl_display = cogl_renderer_egl->edpy;
EGLImageKHR egl_image;
CoglPixelFormat cogl_format;
CoglEglImageFlags flags;
CoglOffscreen *cogl_fbo = NULL;
CoglTexture2D *cogl_tex;
uint32_t n_planes;
uint64_t *modifiers;
uint32_t *strides;
uint32_t *offsets;
uint32_t width;
uint32_t height;
uint32_t drm_format;
int *fds;
gboolean result;
int dmabuf_fd = -1;
uint32_t i;
dmabuf_fd = gbm_bo_get_fd (buffer_gbm->bo);
if (dmabuf_fd == -1)
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_EXISTS,
"Failed to export buffer's DMA fd: %s",
g_strerror (errno));
return FALSE;
}
drm_format = gbm_bo_get_format (buffer_gbm->bo);
result = meta_cogl_pixel_format_from_drm_format (drm_format,
&cogl_format,
NULL);
g_assert (result);
width = gbm_bo_get_width (buffer_gbm->bo);
height = gbm_bo_get_height (buffer_gbm->bo);
n_planes = gbm_bo_get_plane_count (buffer_gbm->bo);
fds = g_alloca (sizeof (int) * n_planes);
strides = g_alloca (sizeof (uint32_t) * n_planes);
offsets = g_alloca (sizeof (uint32_t) * n_planes);
modifiers = g_alloca (sizeof (uint64_t) * n_planes);
for (i = 0; i < n_planes; i++)
{
fds[i] = dmabuf_fd;
strides[i] = gbm_bo_get_stride_for_plane (buffer_gbm->bo, i);
offsets[i] = gbm_bo_get_offset (buffer_gbm->bo, i);
modifiers[i] = gbm_bo_get_modifier (buffer_gbm->bo);
}
egl_image = meta_egl_create_dmabuf_image (egl,
egl_display,
width,
height,
drm_format,
n_planes,
fds,
strides,
offsets,
modifiers,
error);
if (egl_image == EGL_NO_IMAGE_KHR)
{
result = FALSE;
goto out;
}
flags = COGL_EGL_IMAGE_FLAG_NO_GET_DATA;
cogl_tex = cogl_egl_texture_2d_new_from_image (cogl_context,
width,
height,
cogl_format,
egl_image,
flags,
error);
meta_egl_destroy_image (egl, egl_display, egl_image, NULL);
if (!cogl_tex)
{
result = FALSE;
goto out;
}
cogl_fbo = cogl_offscreen_new_with_texture (COGL_TEXTURE (cogl_tex));
cogl_object_unref (cogl_tex);
if (!cogl_framebuffer_allocate (COGL_FRAMEBUFFER (cogl_fbo), error))
{
result = FALSE;
goto out;
}
result = cogl_blit_framebuffer (COGL_FRAMEBUFFER (cogl_fbo),
framebuffer,
0, 0,
x, y,
width, height,
error);
out:
g_clear_object (&cogl_fbo);
close (dmabuf_fd);
return result;
}
static void
cogl_scanout_iface_init (CoglScanoutInterface *iface)
{
iface->blit_to_framebuffer = meta_drm_buffer_gbm_blit_to_framebuffer;
}
static void
meta_drm_buffer_gbm_finalize (GObject *object)
{
MetaDrmBufferGbm *buffer_gbm = META_DRM_BUFFER_GBM (object);
if (buffer_gbm->bo)
{
if (buffer_gbm->surface)
gbm_surface_release_buffer (buffer_gbm->surface, buffer_gbm->bo);
else
gbm_bo_destroy (buffer_gbm->bo);
}
G_OBJECT_CLASS (meta_drm_buffer_gbm_parent_class)->finalize (object);
}
static void
meta_drm_buffer_gbm_init (MetaDrmBufferGbm *buffer_gbm)
{
}
static void
meta_drm_buffer_gbm_class_init (MetaDrmBufferGbmClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
MetaDrmBufferClass *buffer_class = META_DRM_BUFFER_CLASS (klass);
object_class->finalize = meta_drm_buffer_gbm_finalize;
buffer_class->export_fd = meta_drm_buffer_gbm_export_fd;
buffer_class->ensure_fb_id = meta_drm_buffer_gbm_ensure_fb_id;
buffer_class->get_width = meta_drm_buffer_gbm_get_width;
buffer_class->get_height = meta_drm_buffer_gbm_get_height;
buffer_class->get_stride = meta_drm_buffer_gbm_get_stride;
buffer_class->get_bpp = meta_drm_buffer_gbm_get_bpp;
buffer_class->get_format = meta_drm_buffer_gbm_get_format;
buffer_class->get_offset = meta_drm_buffer_gbm_get_offset;
buffer_class->get_modifier = meta_drm_buffer_gbm_get_modifier;
}