path: root/0045-egl-null-add-support-for-DRI_PRIME-GPU-selection.patch

From f1a28e5de789762d9500b86e3e75446ea8e13abf Mon Sep 17 00:00:00 2001
From: Brendan King <Brendan.King@imgtec.com>
Date: Thu, 20 May 2021 20:16:18 +0100
Subject: [PATCH] egl/null: add support for DRI_PRIME GPU selection

Add support for selecting the GPU to be used for rendering using
the DRI_PRIME environment variable. If a different GPU is selected,
a duplicate of the file descriptor for the original GPU/display is
preserved, which can be obtained by calling the getDisplayFD
function in the image loader extension.

This change includes code, in function dri2_null_try_device, to
optionally skip display devices that are not supported by a
particular DRI driver. This can be enabled by setting Meson build
option null-dri-driver-name. This feature is to prevent failure
on PC based test systems, that may have display and GPU hardware
other than that being tested.

---
 meson.build                          |   4 +
 meson_options.txt                    |   6 ++
 src/egl/drivers/dri2/egl_dri2.c      |   1 +
 src/egl/drivers/dri2/platform_null.c | 135 +++++++++++++++++++--------
 src/egl/meson.build                  |   5 +
 5 files changed, 114 insertions(+), 37 deletions(-)

diff --git a/meson.build b/meson.build
index e021a89..a37add4 100644
--- a/meson.build
+++ b/meson.build
@@ -361,6 +361,10 @@ with_platform_haiku = _platforms.contains('haiku')
 with_platform_windows = _platforms.contains('windows')
 with_platform_null = _platforms.contains('null')
 
+if with_platform_null
+  null_dri_driver_name = get_option('null-dri-driver-name')
+endif
+
 with_glx = get_option('glx')
 if with_glx == 'auto'
   if with_platform_android
diff --git a/meson_options.txt b/meson_options.txt
index 65f3254..84661fb 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -37,6 +37,12 @@ option(
   ],
   description : 'the window system EGL assumes for EGL_DEFAULT_DISPLAY',
 )
+option(
+  'null-dri-driver-name',
+  type : 'string',
+  value : '',
+  description : 'For the null platform, ignore all dri drivers apart from this one. By default, no dri drivers are ignored.'
+)
 option(
   'android-stub',
   type : 'boolean',
diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index d0503f6..fce277c 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -1362,6 +1362,7 @@ dri2_display_destroy(_EGLDisplay *disp)
 
    switch (disp->Platform) {
    case _EGL_PLATFORM_DRM:
+   case _EGL_PLATFORM_NULL:
    case _EGL_PLATFORM_WAYLAND:
    case _EGL_PLATFORM_X11:
       if (dri2_dpy->fd_dpy >= 0 && dri2_dpy->fd_dpy != dri2_dpy->fd)
diff --git a/src/egl/drivers/dri2/platform_null.c b/src/egl/drivers/dri2/platform_null.c
index c78e1fe..e2a1383 100644
--- a/src/egl/drivers/dri2/platform_null.c
+++ b/src/egl/drivers/dri2/platform_null.c
@@ -45,6 +45,7 @@
 
 #include "egl_dri2.h"
 #include "loader.h"
+#include "util/os_file.h"
 
 #define NULL_CARD_MINOR_MAX 63U
 
@@ -1045,7 +1046,7 @@ swap_idle_get_target_frame(struct dri2_egl_surface *dri2_surf,
     * current vblank by the number of intervals set at the time swapBuffer
     * is called. For intervals of 1 or 0, we don't need a target frame.
     */
-   err = display_get_vblank_sequence(dri2_dpy->fd, current_vblank_out);
+   err = display_get_vblank_sequence(dri2_dpy->fd_dpy, current_vblank_out);
    if (err)
       return err;
 
@@ -1095,7 +1096,7 @@ swap_vblank_state_transition(struct dri2_egl_surface *dri2_surf,
    uint32_t flags = DRM_VBLANK_ABSOLUTE | DRM_VBLANK_EVENT;
    int err;
 
-   err = display_request_vblank(dri2_dpy->fd, target_frame,
+   err = display_request_vblank(dri2_dpy->fd_dpy, target_frame,
                                 flags, dri2_surf);
    if (err) {
       dri2_surf->swap_state = SWAP_ERROR;
@@ -1121,7 +1122,7 @@ swap_flip_state_transition(struct dri2_egl_surface *dri2_surf)
       flags |= DRM_MODE_PAGE_FLIP_ASYNC;
    }
 
-   err = display_output_flip(dri2_dpy->fd, &dri2_dpy->output,
+   err = display_output_flip(dri2_dpy->fd_dpy, &dri2_dpy->output,
                              dri2_surf->swap_data->fb_id, flags, dri2_surf);
    if (err) {
       dri2_surf->swap_state = SWAP_ERROR;
@@ -1141,7 +1142,7 @@ swap_poll_state_transition(struct dri2_egl_surface *dri2_surf)
    int err;
 
    /* dri2_surf->swap_state is being set inside the handler */
-   err = drm_event_process(dri2_dpy->fd);
+   err = drm_event_process(dri2_dpy->fd_dpy);
    if (err) {
       dri2_surf->swap_state = SWAP_ERROR;
       return err;
@@ -1296,7 +1297,7 @@ add_fb_for_dri_image(struct dri2_egl_display *dri2_dpy, __DRIimage *image,
       handles[i] = (uint32_t) handle;
    }
 
-   return !drmModeAddFB2WithModifiers(dri2_dpy->fd, width, height,
+   return !drmModeAddFB2WithModifiers(dri2_dpy->fd_dpy, width, height,
                                       dri2_null_formats[format_idx].drm_format,
                                       handles, pitches, offsets, modifiers,
                                       fb_id_out, flags);
@@ -1486,7 +1487,7 @@ create_surface(_EGLDisplay *disp, _EGLConfig *config, EGLint type,
    dri2_surf->format = dri2_null_formats[format_idx].dri_image_format;
 
    if (dri2_dpy->in_formats_enabled) {
-      ret = in_formats_get_modifiers(dri2_dpy->fd,
+      ret = in_formats_get_modifiers(dri2_dpy->fd_dpy,
                                      dri2_dpy->output.in_formats_id,
                                      dri2_null_formats[format_idx].drm_format,
                                      &dri2_dpy->output.modifiers);
@@ -1564,7 +1565,7 @@ dri2_null_create_window_surface(_EGLDisplay *disp, _EGLConfig *config,
       goto err_destroy_surface;
    }
 
-   err = display_output_modeset(dri2_dpy->fd, &dri2_dpy->output,
+   err = display_output_modeset(dri2_dpy->fd_dpy, &dri2_dpy->output,
                                 dri2_surf->front_buffer.fb_id);
    if (err) {
       _eglError(EGL_BAD_NATIVE_WINDOW, "window set mode");
@@ -1678,11 +1679,11 @@ dri2_null_destroy_surface(_EGLDisplay *disp, _EGLSurface *surf)
       dri2_dpy->image->destroyImage(dri2_surf->front_buffer.dri_image);
 
    if (dri2_surf->front_buffer.fb_id)
-         drmModeRmFB(dri2_dpy->fd, dri2_surf->front_buffer.fb_id);
+         drmModeRmFB(dri2_dpy->fd_dpy, dri2_surf->front_buffer.fb_id);
 
    for (unsigned i = 0; i < ARRAY_SIZE(dri2_surf->color_buffers); i++) {
       if (dri2_surf->color_buffers[i].fb_id)
-         drmModeRmFB(dri2_dpy->fd, dri2_surf->color_buffers[i].fb_id);
+         drmModeRmFB(dri2_dpy->fd_dpy, dri2_surf->color_buffers[i].fb_id);
       if (dri2_surf->color_buffers[i].dri_image)
          dri2_dpy->image->destroyImage(dri2_surf->color_buffers[i].dri_image);
    }
@@ -1839,12 +1840,22 @@ dri2_null_flush_front_buffer(__DRIdrawable * driDrawable, void *loaderPrivate)
    (void) loaderPrivate;
 }
 
+static int
+dri2_null_get_display_fd(void *loaderPrivate)
+{
+   _EGLDisplay *disp = loaderPrivate;
+   struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
+
+   return dri2_dpy->fd_dpy;
+}
+
 static const __DRIimageLoaderExtension image_loader_extension = {
-   .base = { __DRI_IMAGE_LOADER, 2 },
+   .base = { __DRI_IMAGE_LOADER, 5 },
 
    .getBuffers          = dri2_null_image_get_buffers,
    .flushFrontBuffer    = dri2_null_flush_front_buffer,
    .getCapability       = dri2_null_get_capability,
+   .getDisplayFD        = dri2_null_get_display_fd,
 };
 
 static const __DRIextension *image_loader_extensions[] = {
@@ -1873,12 +1884,74 @@ dri2_null_device_is_kms(int fd)
    return is_kms;
 }
 
+static bool
+dri2_null_try_device(_EGLDisplay *disp)
+{
+   struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
+
+   if (!dri2_null_device_is_kms(dri2_dpy->fd_dpy))
+      return false;
+
+#if defined(NULL_DRI_DRIVER_NAME)
+   /* Skip devices not handled by NULL_DRI_DRIVER_NAME */
+   {
+      char *driver_name = loader_get_driver_for_fd(dri2_dpy->fd_dpy);
+      bool skip = !driver_name || !!strcmp(driver_name, NULL_DRI_DRIVER_NAME);
+
+      free(driver_name);
+
+      if (skip)
+         return false;
+   }
+#endif
+
+   dri2_dpy->fd = os_dupfd_cloexec(dri2_dpy->fd_dpy);
+   if (dri2_dpy->fd < 0) {
+      _eglLog(_EGL_WARNING, "DRI2: failed to dup display FD");
+      dri2_dpy->fd = dri2_dpy->fd_dpy;
+   } else {
+      int fd_old;
+      bool is_different_gpu;
+
+      fd_old = dri2_dpy->fd;
+      dri2_dpy->fd = loader_get_user_preferred_fd(dri2_dpy->fd,
+                                                  &is_different_gpu);
+      if (dri2_dpy->fd == fd_old) {
+         close (dri2_dpy->fd);
+         dri2_dpy->fd = dri2_dpy->fd_dpy;
+      }
+   }
+
+   dri2_dpy->driver_name = loader_get_driver_for_fd(dri2_dpy->fd);
+   if (!dri2_dpy->driver_name)
+      return false;
+
+   if (dri2_load_driver_dri3(disp)) {
+      _EGLDevice *dev = _eglAddDevice(dri2_dpy->fd, false);
+      if (!dev) {
+         dlclose(dri2_dpy->driver);
+         _eglLog(_EGL_WARNING, "DRI2: failed to find EGLDevice");
+      } else {
+         dri2_dpy->loader_extensions = image_loader_extensions;
+         dri2_dpy->own_device = 1;
+         disp->Device = dev;
+         return true;
+      }
+   }
+
+   free(dri2_dpy->driver_name);
+   dri2_dpy->driver_name = NULL;
+
+   return false;
+}
+
 static bool
 dri2_null_probe_device(_EGLDisplay *disp)
 {
    struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
 
    dri2_dpy->fd = -1;
+   dri2_dpy->fd_dpy = -1;
 
    for (unsigned i = 0; i <= NULL_CARD_MINOR_MAX; i++) {
       char *card_path;
@@ -1886,32 +1959,20 @@ dri2_null_probe_device(_EGLDisplay *disp)
       if (asprintf(&card_path, DRM_DEV_NAME, DRM_DIR_NAME, i) < 0)
          continue;
 
-      dri2_dpy->fd = loader_open_device(card_path);
+      dri2_dpy->fd_dpy = loader_open_device(card_path);
       free(card_path);
-      if (dri2_dpy->fd < 0)
+      if (dri2_dpy->fd_dpy < 0)
          continue;
 
-      if (dri2_null_device_is_kms(dri2_dpy->fd)) {
-         dri2_dpy->driver_name = loader_get_driver_for_fd(dri2_dpy->fd);
-         if (dri2_dpy->driver_name) {
-            if (dri2_load_driver_dri3(disp)) {
-               _EGLDevice *dev = _eglAddDevice(dri2_dpy->fd, false);
-               if (!dev) {
-                  dlclose(dri2_dpy->driver);
-                  _eglLog(_EGL_WARNING, "DRI2: failed to find EGLDevice");
-               } else {
-                  dri2_dpy->loader_extensions = image_loader_extensions;
-                  dri2_dpy->own_device = 1;
-                  disp->Device = dev;
-                  return true;
-               }
-            }
-            free(dri2_dpy->driver_name);
-            dri2_dpy->driver_name = NULL;
-         }
-      }
+      if (dri2_null_try_device(disp))
+         return true;
+
+      close(dri2_dpy->fd_dpy);
+
+      if (dri2_dpy->fd >= 0 && dri2_dpy->fd != dri2_dpy->fd_dpy)
+         close(dri2_dpy->fd);
 
-      close(dri2_dpy->fd);
+      dri2_dpy->fd_dpy = -1;
       dri2_dpy->fd = -1;
    }
 
@@ -1972,7 +2033,7 @@ dri2_null_setup_swap_interval(_EGLDisplay *disp)
 
    dri2_setup_swap_interval(disp, swap_max_interval);
 
-   err = drmGetCap(dri2_dpy->fd, DRM_CAP_ASYNC_PAGE_FLIP, &value);
+   err = drmGetCap(dri2_dpy->fd_dpy, DRM_CAP_ASYNC_PAGE_FLIP, &value);
    if (err || value == 0) {
 
       /* DRM/KMS does not support async page flip. In order to support
@@ -2020,7 +2081,7 @@ dri2_initialize_null(_EGLDisplay *disp)
     * modesetting if not. If this succeeds then universal planes will also have
     * been enabled.
     */
-   err = drmSetClientCap(dri2_dpy->fd, DRM_CLIENT_CAP_ATOMIC, 1);
+   err = drmSetClientCap(dri2_dpy->fd_dpy, DRM_CLIENT_CAP_ATOMIC, 1);
    dri2_dpy->atomic_enabled = !err;
 
    if (!dri2_dpy->atomic_enabled) {
@@ -2028,7 +2089,7 @@ dri2_initialize_null(_EGLDisplay *disp)
        * Enable universal planes so that we can get the pixel formats for the
        * primary plane
        */
-      err = drmSetClientCap(dri2_dpy->fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);
+      err = drmSetClientCap(dri2_dpy->fd_dpy, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);
       if (err) {
          _eglError(EGL_NOT_INITIALIZED, "failed to enable universal planes");
          goto cleanup;
@@ -2064,7 +2125,7 @@ dri2_initialize_null(_EGLDisplay *disp)
          dri2_dpy->image->createImageWithModifiers;
    }
 
-   if (!display_output_init(dri2_dpy->fd, &dri2_dpy->output,
+   if (!display_output_init(dri2_dpy->fd_dpy, &dri2_dpy->output,
                             dri2_dpy->atomic_enabled,
                             prefer_in_formats,
                             &dri2_dpy->in_formats_enabled)) {
@@ -2098,7 +2159,7 @@ dri2_teardown_null(struct dri2_egl_display *dri2_dpy)
    drmModeAtomicFree(dri2_dpy->output.atomic_state);
 
    if (dri2_dpy->output.mode_blob_id)
-      drmModeDestroyPropertyBlob(dri2_dpy->fd, dri2_dpy->output.mode_blob_id);
+      drmModeDestroyPropertyBlob(dri2_dpy->fd_dpy, dri2_dpy->output.mode_blob_id);
 
    if (dri2_dpy->output.plane_prop_res) {
       for (unsigned i = 0; dri2_dpy->output.plane_prop_res[i]; i++)
diff --git a/src/egl/meson.build b/src/egl/meson.build
index a08f1c7..4aa9f5f 100644
--- a/src/egl/meson.build
+++ b/src/egl/meson.build
@@ -151,6 +151,11 @@ elif with_platform_windows
   link_for_egl += libgallium_wgl
 endif
 if with_platform_null
+  if null_dri_driver_name != ''
+    c_args_for_egl += [
+      '-DNULL_DRI_DRIVER_NAME="@0@"'.format(null_dri_driver_name),
+    ]
+  endif
   files_egl += files('drivers/dri2/platform_null.c')
   incs_for_egl += [inc_loader]
   deps_for_egl += dep_libdrm