/*
 * Copyright © 2011-2012 Intel Corporation
 * Copyright © 2012 Collabora, Ltd.
 *
 * 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:
 *    Kristian Høgsberg <krh@bitplanet.net>
 *    Benjamin Franzke <benjaminfranzke@googlemail.com>
 */

#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <dlfcn.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <xf86drm.h>
#include <sys/mman.h>

#include "egl_dri2.h"
#include "egl_dri2_fallbacks.h"
#include "loader.h"

#include <wayland-client.h>
#include "wayland-drm-client-protocol.h"

enum wl_drm_format_flags {
   HAS_ARGB8888 = 1,
   HAS_XRGB8888 = 2,
   HAS_RGB565 = 4,
};

static EGLBoolean
dri2_wl_swap_interval(_EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *surf,
                      EGLint interval);

static void
sync_callback(void *data, struct wl_callback *callback, uint32_t serial)
{
   int *done = data;

   *done = 1;
   wl_callback_destroy(callback);
}

static const struct wl_callback_listener sync_listener = {
   .done = sync_callback
};

static int
roundtrip(struct dri2_egl_display *dri2_dpy)
{
   struct wl_callback *callback;
   int done = 0, ret = 0;

   callback = wl_display_sync(dri2_dpy->wl_dpy);
   wl_callback_add_listener(callback, &sync_listener, &done);
   wl_proxy_set_queue((struct wl_proxy *) callback, dri2_dpy->wl_queue);
   while (ret != -1 && !done)
      ret = wl_display_dispatch_queue(dri2_dpy->wl_dpy, dri2_dpy->wl_queue);

   if (!done)
      wl_callback_destroy(callback);

   return ret;
}

static void
wl_buffer_release(void *data, struct wl_buffer *buffer)
{
   struct dri2_egl_surface *dri2_surf = data;
   int i;

   for (i = 0; i < ARRAY_SIZE(dri2_surf->color_buffers); ++i)
      if (dri2_surf->color_buffers[i].wl_buffer == buffer)
         break;

   if (i == ARRAY_SIZE(dri2_surf->color_buffers)) {
      wl_buffer_destroy(buffer);
      return;
   }

   dri2_surf->color_buffers[i].locked = 0;
}

static const struct wl_buffer_listener wl_buffer_listener = {
   .release = wl_buffer_release
};

static void
resize_callback(struct wl_egl_window *wl_win, void *data)
{
   struct dri2_egl_surface *dri2_surf = data;
   struct dri2_egl_display *dri2_dpy =
      dri2_egl_display(dri2_surf->base.Resource.Display);

   (*dri2_dpy->flush->invalidate)(dri2_surf->dri_drawable);
}

static void
destroy_window_callback(void *data)
{
   struct dri2_egl_surface *dri2_surf = data;
   dri2_surf->wl_win = NULL;
}

/**
 * Called via eglCreateWindowSurface(), drv->API.CreateWindowSurface().
 */
static _EGLSurface *
dri2_wl_create_surface(_EGLDriver *drv, _EGLDisplay *disp,
                       _EGLConfig *conf, void *native_window,
                       const EGLint *attrib_list)
{
   struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
   struct dri2_egl_config *dri2_conf = dri2_egl_config(conf);
   struct wl_egl_window *window = native_window;
   struct dri2_egl_surface *dri2_surf;
   const __DRIconfig *config;

   (void) drv;

   dri2_surf = calloc(1, sizeof *dri2_surf);
   if (!dri2_surf) {
      _eglError(EGL_BAD_ALLOC, "dri2_create_surface");
      return NULL;
   }

   if (!_eglInitSurface(&dri2_surf->base, disp, EGL_WINDOW_BIT, conf, attrib_list))
      goto cleanup_surf;

   if (conf->RedSize == 5)
      dri2_surf->format = WL_DRM_FORMAT_RGB565;
   else if (conf->AlphaSize == 0)
      dri2_surf->format = WL_DRM_FORMAT_XRGB8888;
   else
      dri2_surf->format = WL_DRM_FORMAT_ARGB8888;

   if (!window) {
      _eglError(EGL_BAD_NATIVE_WINDOW, "dri2_create_surface");
      goto cleanup_surf;
   }

   dri2_surf->wl_win = window;

   dri2_surf->wl_win->private = dri2_surf;
   dri2_surf->wl_win->resize_callback = resize_callback;
   dri2_surf->wl_win->destroy_window_callback = destroy_window_callback;

   dri2_surf->base.Width =  -1;
   dri2_surf->base.Height = -1;

   config = dri2_get_dri_config(dri2_conf, EGL_WINDOW_BIT,
                                dri2_surf->base.GLColorspace);

   dri2_surf->dri_drawable = 
      (*dri2_dpy->dri2->createNewDrawable)(dri2_dpy->dri_screen, config,
                                           dri2_surf);
   if (dri2_surf->dri_drawable == NULL) {
      _eglError(EGL_BAD_ALLOC, "dri2->createNewDrawable");
      goto cleanup_surf;
   }

   return &dri2_surf->base;

 cleanup_surf:
   free(dri2_surf);

   return NULL;
}

/**
 * Called via eglCreateWindowSurface(), drv->API.CreateWindowSurface().
 */
static _EGLSurface *
dri2_wl_create_window_surface(_EGLDriver *drv, _EGLDisplay *disp,
                              _EGLConfig *conf, void *native_window,
                              const EGLint *attrib_list)
{
   struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
   _EGLSurface *surf;

   surf = dri2_wl_create_surface(drv, disp, conf, native_window, attrib_list);

   if (surf != NULL)
      dri2_wl_swap_interval(drv, disp, surf, dri2_dpy->default_swap_interval);

   return surf;
}

static _EGLSurface *
dri2_wl_create_pixmap_surface(_EGLDriver *drv, _EGLDisplay *disp,
                              _EGLConfig *conf, void *native_window,
                              const EGLint *attrib_list)
{
   /* From the EGL_EXT_platform_wayland spec, version 3:
    *
    *   It is not valid to call eglCreatePlatformPixmapSurfaceEXT with a <dpy>
    *   that belongs to Wayland. Any such call fails and generates
    *   EGL_BAD_PARAMETER.
    */
   _eglError(EGL_BAD_PARAMETER, "cannot create EGL pixmap surfaces on "
             "Wayland");
   return NULL;
}

/**
 * Called via eglDestroySurface(), drv->API.DestroySurface().
 */
static EGLBoolean
dri2_wl_destroy_surface(_EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *surf)
{
   struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
   struct dri2_egl_surface *dri2_surf = dri2_egl_surface(surf);
   int i;

   (void) drv;

   (*dri2_dpy->core->destroyDrawable)(dri2_surf->dri_drawable);

   for (i = 0; i < ARRAY_SIZE(dri2_surf->color_buffers); i++) {
      if (dri2_surf->color_buffers[i].wl_buffer)
         wl_buffer_destroy(dri2_surf->color_buffers[i].wl_buffer);
      if (dri2_surf->color_buffers[i].dri_image)
         dri2_dpy->image->destroyImage(dri2_surf->color_buffers[i].dri_image);
      if (dri2_surf->color_buffers[i].linear_copy)
         dri2_dpy->image->destroyImage(dri2_surf->color_buffers[i].linear_copy);
      if (dri2_surf->color_buffers[i].data)
         munmap(dri2_surf->color_buffers[i].data,
                dri2_surf->color_buffers[i].data_size);
   }

   if (dri2_dpy->dri2) {
      for (i = 0; i < __DRI_BUFFER_COUNT; i++)
         if (dri2_surf->dri_buffers[i] &&
             dri2_surf->dri_buffers[i]->attachment != __DRI_BUFFER_BACK_LEFT)
            dri2_dpy->dri2->releaseBuffer(dri2_dpy->dri_screen,
                                          dri2_surf->dri_buffers[i]);
   }

   if (dri2_surf->throttle_callback)
      wl_callback_destroy(dri2_surf->throttle_callback);

   if (dri2_surf->wl_win) {
      dri2_surf->wl_win->private = NULL;
      dri2_surf->wl_win->resize_callback = NULL;
      dri2_surf->wl_win->destroy_window_callback = NULL;
   }

   free(surf);

   return EGL_TRUE;
}

static void
dri2_wl_release_buffers(struct dri2_egl_surface *dri2_surf)
{
   struct dri2_egl_display *dri2_dpy =
      dri2_egl_display(dri2_surf->base.Resource.Display);
   int i;

   for (i = 0; i < ARRAY_SIZE(dri2_surf->color_buffers); i++) {
      if (dri2_surf->color_buffers[i].wl_buffer &&
          !dri2_surf->color_buffers[i].locked)
         wl_buffer_destroy(dri2_surf->color_buffers[i].wl_buffer);
      if (dri2_surf->color_buffers[i].dri_image)
         dri2_dpy->image->destroyImage(dri2_surf->color_buffers[i].dri_image);
      if (dri2_surf->color_buffers[i].linear_copy)
         dri2_dpy->image->destroyImage(dri2_surf->color_buffers[i].linear_copy);
      if (dri2_surf->color_buffers[i].data)
         munmap(dri2_surf->color_buffers[i].data,
                dri2_surf->color_buffers[i].data_size);

      dri2_surf->color_buffers[i].wl_buffer = NULL;
      dri2_surf->color_buffers[i].dri_image = NULL;
      dri2_surf->color_buffers[i].linear_copy = NULL;
      dri2_surf->color_buffers[i].data = NULL;
      dri2_surf->color_buffers[i].locked = 0;
   }

   if (dri2_dpy->dri2) {
      for (i = 0; i < __DRI_BUFFER_COUNT; i++)
         if (dri2_surf->dri_buffers[i] &&
             dri2_surf->dri_buffers[i]->attachment != __DRI_BUFFER_BACK_LEFT)
            dri2_dpy->dri2->releaseBuffer(dri2_dpy->dri_screen,
                                          dri2_surf->dri_buffers[i]);
   }
}

static int
get_back_bo(struct dri2_egl_surface *dri2_surf)
{
   struct dri2_egl_display *dri2_dpy =
      dri2_egl_display(dri2_surf->base.Resource.Display);
   int i, use_flags;
   unsigned int dri_image_format;

   /* currently supports three WL DRM formats,
    * WL_DRM_FORMAT_ARGB8888, WL_DRM_FORMAT_XRGB8888,
    * and WL_DRM_FORMAT_RGB565
    */
   switch (dri2_surf->format) {
   case WL_DRM_FORMAT_ARGB8888:
      dri_image_format = __DRI_IMAGE_FORMAT_ARGB8888;
      break;
   case WL_DRM_FORMAT_XRGB8888:
      dri_image_format = __DRI_IMAGE_FORMAT_XRGB8888;
      break;
   case WL_DRM_FORMAT_RGB565:
      dri_image_format = __DRI_IMAGE_FORMAT_RGB565;
      break;
   default:
      /* format is not supported */
      return -1;
   }

   /* There might be a buffer release already queued that wasn't processed */
   wl_display_dispatch_queue_pending(dri2_dpy->wl_dpy, dri2_dpy->wl_queue);

   if (dri2_surf->back == NULL) {
      for (i = 0; i < ARRAY_SIZE(dri2_surf->color_buffers); i++) {
         /* Get an unlocked buffer, preferrably one with a dri_buffer
          * already allocated. */
         if (dri2_surf->color_buffers[i].locked)
            continue;
         if (dri2_surf->back == NULL)
            dri2_surf->back = &dri2_surf->color_buffers[i];
         else if (dri2_surf->back->dri_image == NULL)
            dri2_surf->back = &dri2_surf->color_buffers[i];
      }
   }

   if (dri2_surf->back == NULL)
      return -1;

   use_flags = __DRI_IMAGE_USE_SHARE | __DRI_IMAGE_USE_BACKBUFFER;

   if (dri2_dpy->is_different_gpu &&
       dri2_surf->back->linear_copy == NULL) {
       dri2_surf->back->linear_copy =
          dri2_dpy->image->createImage(dri2_dpy->dri_screen,
                                      dri2_surf->base.Width,
                                      dri2_surf->base.Height,
                                      dri_image_format,
                                      use_flags |
                                      __DRI_IMAGE_USE_LINEAR,
                                      NULL);
      if (dri2_surf->back->linear_copy == NULL)
          return -1;
   }

   if (dri2_surf->back->dri_image == NULL) {
      dri2_surf->back->dri_image =
         dri2_dpy->image->createImage(dri2_dpy->dri_screen,
                                      dri2_surf->base.Width,
                                      dri2_surf->base.Height,
                                      dri_image_format,
                                      dri2_dpy->is_different_gpu ?
                                         0 : use_flags,
                                      NULL);
      dri2_surf->back->age = 0;
   }
   if (dri2_surf->back->dri_image == NULL)
      return -1;

   dri2_surf->back->locked = 1;

   return 0;
}


static void
back_bo_to_dri_buffer(struct dri2_egl_surface *dri2_surf, __DRIbuffer *buffer)
{
   struct dri2_egl_display *dri2_dpy =
      dri2_egl_display(dri2_surf->base.Resource.Display);
   __DRIimage *image;
   int name, pitch;

   image = dri2_surf->back->dri_image;

   dri2_dpy->image->queryImage(image, __DRI_IMAGE_ATTRIB_NAME, &name);
   dri2_dpy->image->queryImage(image, __DRI_IMAGE_ATTRIB_STRIDE, &pitch);

   buffer->attachment = __DRI_BUFFER_BACK_LEFT;
   buffer->name = name;
   buffer->pitch = pitch;
   buffer->cpp = 4;
   buffer->flags = 0;
}

static int
get_aux_bo(struct dri2_egl_surface *dri2_surf,
	   unsigned int attachment, unsigned int format, __DRIbuffer *buffer)
{
   struct dri2_egl_display *dri2_dpy =
      dri2_egl_display(dri2_surf->base.Resource.Display);
   __DRIbuffer *b = dri2_surf->dri_buffers[attachment];

   if (b == NULL) {
      b = dri2_dpy->dri2->allocateBuffer(dri2_dpy->dri_screen,
					 attachment, format,
					 dri2_surf->base.Width,
					 dri2_surf->base.Height);
      dri2_surf->dri_buffers[attachment] = b;
   }
   if (b == NULL)
      return -1;

   memcpy(buffer, b, sizeof *buffer);

   return 0;
}

static int
update_buffers(struct dri2_egl_surface *dri2_surf)
{
   struct dri2_egl_display *dri2_dpy =
      dri2_egl_display(dri2_surf->base.Resource.Display);
   int i;

   if (dri2_surf->base.Width != dri2_surf->wl_win->width ||
       dri2_surf->base.Height != dri2_surf->wl_win->height) {

      dri2_wl_release_buffers(dri2_surf);

      dri2_surf->base.Width  = dri2_surf->wl_win->width;
      dri2_surf->base.Height = dri2_surf->wl_win->height;
      dri2_surf->dx = dri2_surf->wl_win->dx;
      dri2_surf->dy = dri2_surf->wl_win->dy;
   }

   if (get_back_bo(dri2_surf) < 0) {
      _eglError(EGL_BAD_ALLOC, "failed to allocate color buffer");
      return -1;
   }

   /* If we have an extra unlocked buffer at this point, we had to do triple
    * buffering for a while, but now can go back to just double buffering.
    * That means we can free any unlocked buffer now. */
   for (i = 0; i < ARRAY_SIZE(dri2_surf->color_buffers); i++) {
      if (!dri2_surf->color_buffers[i].locked &&
          dri2_surf->color_buffers[i].wl_buffer) {
         wl_buffer_destroy(dri2_surf->color_buffers[i].wl_buffer);
         dri2_dpy->image->destroyImage(dri2_surf->color_buffers[i].dri_image);
         if (dri2_dpy->is_different_gpu)
            dri2_dpy->image->destroyImage(dri2_surf->color_buffers[i].linear_copy);
         dri2_surf->color_buffers[i].wl_buffer = NULL;
         dri2_surf->color_buffers[i].dri_image = NULL;
         dri2_surf->color_buffers[i].linear_copy = NULL;
      }
   }

   return 0;
}

static __DRIbuffer *
dri2_wl_get_buffers_with_format(__DRIdrawable * driDrawable,
                                int *width, int *height,
                                unsigned int *attachments, int count,
                                int *out_count, void *loaderPrivate)
{
   struct dri2_egl_surface *dri2_surf = loaderPrivate;
   int i, j;

   if (update_buffers(dri2_surf) < 0)
      return NULL;

   for (i = 0, j = 0; i < 2 * count; i += 2, j++) {
      switch (attachments[i]) {
      case __DRI_BUFFER_BACK_LEFT:
         back_bo_to_dri_buffer(dri2_surf, &dri2_surf->buffers[j]);
	 break;
      default:
	 if (get_aux_bo(dri2_surf, attachments[i], attachments[i + 1],
			&dri2_surf->buffers[j]) < 0) {
	    _eglError(EGL_BAD_ALLOC, "failed to allocate aux buffer");
	    return NULL;
	 }
	 break;
      }
   }

   *out_count = j;
   if (j == 0)
	   return NULL;

   *width = dri2_surf->base.Width;
   *height = dri2_surf->base.Height;

   return dri2_surf->buffers;
}

static __DRIbuffer *
dri2_wl_get_buffers(__DRIdrawable * driDrawable,
                    int *width, int *height,
                    unsigned int *attachments, int count,
                    int *out_count, void *loaderPrivate)
{
   struct dri2_egl_surface *dri2_surf = loaderPrivate;
   unsigned int *attachments_with_format;
   __DRIbuffer *buffer;
   unsigned int bpp;

   int i;

   switch (dri2_surf->format) {
   case WL_DRM_FORMAT_ARGB8888:
   case WL_DRM_FORMAT_XRGB8888:
      bpp = 32;
      break;
   case WL_DRM_FORMAT_RGB565:
      bpp = 16;
      break;
   default:
      /* format is not supported */
      return NULL;
   }

   attachments_with_format = calloc(count, 2 * sizeof(unsigned int));
   if (!attachments_with_format) {
      *out_count = 0;
      return NULL;
   }

   for (i = 0; i < count; ++i) {
      attachments_with_format[2*i] = attachments[i];
      attachments_with_format[2*i + 1] = bpp;
   }

   buffer =
      dri2_wl_get_buffers_with_format(driDrawable,
                                      width, height,
                                      attachments_with_format, count,
                                      out_count, loaderPrivate);

   free(attachments_with_format);

   return buffer;
}

static int
image_get_buffers(__DRIdrawable *driDrawable,
                  unsigned int format,
                  uint32_t *stamp,
                  void *loaderPrivate,
                  uint32_t buffer_mask,
                  struct __DRIimageList *buffers)
{
   struct dri2_egl_surface *dri2_surf = loaderPrivate;

   if (update_buffers(dri2_surf) < 0)
      return 0;

   buffers->image_mask = __DRI_IMAGE_BUFFER_BACK;
   buffers->back = dri2_surf->back->dri_image;

   return 1;
}

static void
dri2_wl_flush_front_buffer(__DRIdrawable * driDrawable, void *loaderPrivate)
{
   (void) driDrawable;
   (void) loaderPrivate;
}

static const __DRIdri2LoaderExtension dri2_loader_extension = {
   .base = { __DRI_DRI2_LOADER, 3 },

   .getBuffers           = dri2_wl_get_buffers,
   .flushFrontBuffer     = dri2_wl_flush_front_buffer,
   .getBuffersWithFormat = dri2_wl_get_buffers_with_format,
};

static const __DRIimageLoaderExtension image_loader_extension = {
   .base = { __DRI_IMAGE_LOADER, 1 },

   .getBuffers          = image_get_buffers,
   .flushFrontBuffer    = dri2_wl_flush_front_buffer,
};

static void
wayland_throttle_callback(void *data,
                          struct wl_callback *callback,
                          uint32_t time)
{
   struct dri2_egl_surface *dri2_surf = data;

   dri2_surf->throttle_callback = NULL;
   wl_callback_destroy(callback);
}

static const struct wl_callback_listener throttle_listener = {
   .done = wayland_throttle_callback
};

static void
create_wl_buffer(struct dri2_egl_surface *dri2_surf)
{
   struct dri2_egl_display *dri2_dpy =
      dri2_egl_display(dri2_surf->base.Resource.Display);
   __DRIimage *image;
   int fd, stride, name;

   if (dri2_surf->current->wl_buffer != NULL)
      return;

   if (dri2_dpy->is_different_gpu) {
      image = dri2_surf->current->linear_copy;
   } else {
      image = dri2_surf->current->dri_image;
   }
   if (dri2_dpy->capabilities & WL_DRM_CAPABILITY_PRIME) {
      dri2_dpy->image->queryImage(image, __DRI_IMAGE_ATTRIB_FD, &fd);
      dri2_dpy->image->queryImage(image, __DRI_IMAGE_ATTRIB_STRIDE, &stride);

      dri2_surf->current->wl_buffer =
         wl_drm_create_prime_buffer(dri2_dpy->wl_drm,
                                    fd,
                                    dri2_surf->base.Width,
                                    dri2_surf->base.Height,
                                    dri2_surf->format,
                                    0, stride,
                                    0, 0,
                                    0, 0);
      close(fd);
   } else {
      dri2_dpy->image->queryImage(image, __DRI_IMAGE_ATTRIB_NAME, &name);
      dri2_dpy->image->queryImage(image, __DRI_IMAGE_ATTRIB_STRIDE, &stride);

      dri2_surf->current->wl_buffer =
         wl_drm_create_buffer(dri2_dpy->wl_drm,
                              name,
                              dri2_surf->base.Width,
                              dri2_surf->base.Height,
                              stride,
                              dri2_surf->format);
   }

   wl_proxy_set_queue((struct wl_proxy *) dri2_surf->current->wl_buffer,
                      dri2_dpy->wl_queue);
   wl_buffer_add_listener(dri2_surf->current->wl_buffer,
                          &wl_buffer_listener, dri2_surf);
}

static EGLBoolean
try_damage_buffer(struct dri2_egl_surface *dri2_surf,
                  const EGLint *rects,
                  EGLint n_rects)
{
/* The WL_SURFACE_DAMAGE_BUFFER_SINCE_VERSION macro and
 * wl_proxy_get_version() were both introduced in wayland 1.10.
 * Instead of bumping our wayland dependency we just make this
 * function conditional on the required 1.10 features, falling
 * back to old (correct but suboptimal) behaviour for older
 * wayland.
 */
#ifdef WL_SURFACE_DAMAGE_BUFFER_SINCE_VERSION
   int i;

   if (wl_proxy_get_version((struct wl_proxy *) dri2_surf->wl_win->surface)
       < WL_SURFACE_DAMAGE_BUFFER_SINCE_VERSION)
      return EGL_FALSE;

   for (i = 0; i < n_rects; i++) {
      const int *rect = &rects[i * 4];

      wl_surface_damage_buffer(dri2_surf->wl_win->surface,
                               rect[0],
                               dri2_surf->base.Height - rect[1] - rect[3],
                               rect[2], rect[3]);
   }
   return EGL_TRUE;
#endif
   return EGL_FALSE;
}
/**
 * Called via eglSwapBuffers(), drv->API.SwapBuffers().
 */
static EGLBoolean
dri2_wl_swap_buffers_with_damage(_EGLDriver *drv,
                                 _EGLDisplay *disp,
                                 _EGLSurface *draw,
                                 const EGLint *rects,
                                 EGLint n_rects)
{
   struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
   struct dri2_egl_surface *dri2_surf = dri2_egl_surface(draw);
   int i;

   while (dri2_surf->throttle_callback != NULL)
      if (wl_display_dispatch_queue(dri2_dpy->wl_dpy,
                                    dri2_dpy->wl_queue) == -1)
         return -1;

   for (i = 0; i < ARRAY_SIZE(dri2_surf->color_buffers); i++)
      if (dri2_surf->color_buffers[i].age > 0)
         dri2_surf->color_buffers[i].age++;

   /* Make sure we have a back buffer in case we're swapping without ever
    * rendering. */
   if (get_back_bo(dri2_surf) < 0) {
      _eglError(EGL_BAD_ALLOC, "dri2_swap_buffers");
      return EGL_FALSE;
   }

   if (draw->SwapInterval > 0) {
      dri2_surf->throttle_callback =
         wl_surface_frame(dri2_surf->wl_win->surface);
      wl_callback_add_listener(dri2_surf->throttle_callback,
                               &throttle_listener, dri2_surf);
      wl_proxy_set_queue((struct wl_proxy *) dri2_surf->throttle_callback,
                         dri2_dpy->wl_queue);
   }

   dri2_surf->back->age = 1;
   dri2_surf->current = dri2_surf->back;
   dri2_surf->back = NULL;

   create_wl_buffer(dri2_surf);

   wl_surface_attach(dri2_surf->wl_win->surface,
                     dri2_surf->current->wl_buffer,
                     dri2_surf->dx, dri2_surf->dy);

   dri2_surf->wl_win->attached_width  = dri2_surf->base.Width;
   dri2_surf->wl_win->attached_height = dri2_surf->base.Height;
   /* reset resize growing parameters */
   dri2_surf->dx = 0;
   dri2_surf->dy = 0;

   /* If the compositor doesn't support damage_buffer, we deliberately
    * ignore the damage region and post maximum damage, due to
    * https://bugs.freedesktop.org/78190 */
   if (!n_rects || !try_damage_buffer(dri2_surf, rects, n_rects))
      wl_surface_damage(dri2_surf->wl_win->surface,
                        0, 0, INT32_MAX, INT32_MAX);

   if (dri2_dpy->is_different_gpu) {
      _EGLContext *ctx = _eglGetCurrentContext();
      struct dri2_egl_context *dri2_ctx = dri2_egl_context(ctx);
      dri2_dpy->image->blitImage(dri2_ctx->dri_context,
                                 dri2_surf->current->linear_copy,
                                 dri2_surf->current->dri_image,
                                 0, 0, dri2_surf->base.Width,
                                 dri2_surf->base.Height,
                                 0, 0, dri2_surf->base.Width,
                                 dri2_surf->base.Height, 0);
   }

   dri2_flush_drawable_for_swapbuffers(disp, draw);
   (*dri2_dpy->flush->invalidate)(dri2_surf->dri_drawable);

   wl_surface_commit(dri2_surf->wl_win->surface);

   /* If we're not waiting for a frame callback then we'll at least throttle
    * to a sync callback so that we always give a chance for the compositor to
    * handle the commit and send a release event before checking for a free
    * buffer */
   if (dri2_surf->throttle_callback == NULL) {
      dri2_surf->throttle_callback = wl_display_sync(dri2_dpy->wl_dpy);
      wl_callback_add_listener(dri2_surf->throttle_callback,
                               &throttle_listener, dri2_surf);
      wl_proxy_set_queue((struct wl_proxy *) dri2_surf->throttle_callback,
                         dri2_dpy->wl_queue);
   }

   wl_display_flush(dri2_dpy->wl_dpy);

   return EGL_TRUE;
}

static EGLint
dri2_wl_query_buffer_age(_EGLDriver *drv,
                         _EGLDisplay *disp, _EGLSurface *surface)
{
   struct dri2_egl_surface *dri2_surf = dri2_egl_surface(surface);

   if (get_back_bo(dri2_surf) < 0) {
      _eglError(EGL_BAD_ALLOC, "dri2_query_buffer_age");
      return 0;
   }

   return dri2_surf->back->age;
}

static EGLBoolean
dri2_wl_swap_buffers(_EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *draw)
{
   return dri2_wl_swap_buffers_with_damage (drv, disp, draw, NULL, 0);
}

static struct wl_buffer *
dri2_wl_create_wayland_buffer_from_image(_EGLDriver *drv,
                                          _EGLDisplay *disp,
                                          _EGLImage *img)
{
   struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
   struct dri2_egl_image *dri2_img = dri2_egl_image(img);
   __DRIimage *image = dri2_img->dri_image;
   struct wl_buffer *buffer;
   int width, height, format, pitch;
   enum wl_drm_format wl_format;

   dri2_dpy->image->queryImage(image, __DRI_IMAGE_ATTRIB_FORMAT, &format);

   switch (format) {
   case __DRI_IMAGE_FORMAT_ARGB8888:
      if (!(dri2_dpy->formats & HAS_ARGB8888))
         goto bad_format;
      wl_format = WL_DRM_FORMAT_ARGB8888;
      break;
   case __DRI_IMAGE_FORMAT_XRGB8888:
      if (!(dri2_dpy->formats & HAS_XRGB8888))
         goto bad_format;
      wl_format = WL_DRM_FORMAT_XRGB8888;
      break;
   default:
      goto bad_format;
   }

   dri2_dpy->image->queryImage(image, __DRI_IMAGE_ATTRIB_WIDTH, &width);
   dri2_dpy->image->queryImage(image, __DRI_IMAGE_ATTRIB_HEIGHT, &height);
   dri2_dpy->image->queryImage(image, __DRI_IMAGE_ATTRIB_STRIDE, &pitch);

   if (dri2_dpy->capabilities & WL_DRM_CAPABILITY_PRIME) {
      int fd;

      dri2_dpy->image->queryImage(image, __DRI_IMAGE_ATTRIB_FD, &fd);

      buffer =
         wl_drm_create_prime_buffer(dri2_dpy->wl_drm,
                                    fd,
                                    width, height,
                                    wl_format,
                                    0, pitch,
                                    0, 0,
                                    0, 0);

      close(fd);
   } else {
      int name;

      dri2_dpy->image->queryImage(image, __DRI_IMAGE_ATTRIB_NAME, &name);

      buffer =
         wl_drm_create_buffer(dri2_dpy->wl_drm,
                              name,
                              width, height,
                              pitch,
                              wl_format);
   }

   /* The buffer object will have been created with our internal event queue
    * because it is using the wl_drm object as a proxy factory. We want the
    * buffer to be used by the application so we'll reset it to the display's
    * default event queue */
   if (buffer)
      wl_proxy_set_queue((struct wl_proxy *) buffer, NULL);

   return buffer;

bad_format:
   _eglError(EGL_BAD_MATCH, "unsupported image format");
   return NULL;
}

static int
dri2_wl_authenticate(_EGLDisplay *disp, uint32_t id)
{
   struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
   int ret = 0;

   if (dri2_dpy->is_render_node) {
      _eglLog(_EGL_WARNING, "wayland-egl: client asks server to "
                            "authenticate for render-nodes");
      return 0;
   }
   dri2_dpy->authenticated = 0;

   wl_drm_authenticate(dri2_dpy->wl_drm, id);
   if (roundtrip(dri2_dpy) < 0)
      ret = -1;

   if (!dri2_dpy->authenticated)
      ret = -1;

   /* reset authenticated */
   dri2_dpy->authenticated = 1;

   return ret;
}

static void
drm_handle_device(void *data, struct wl_drm *drm, const char *device)
{
   struct dri2_egl_display *dri2_dpy = data;
   drm_magic_t magic;

   dri2_dpy->device_name = strdup(device);
   if (!dri2_dpy->device_name)
      return;

   dri2_dpy->fd = loader_open_device(dri2_dpy->device_name);
   if (dri2_dpy->fd == -1) {
      _eglLog(_EGL_WARNING, "wayland-egl: could not open %s (%s)",
	      dri2_dpy->device_name, strerror(errno));
      return;
   }

   if (drmGetNodeTypeFromFd(dri2_dpy->fd) == DRM_NODE_RENDER) {
      dri2_dpy->authenticated = 1;
   } else {
      drmGetMagic(dri2_dpy->fd, &magic);
      wl_drm_authenticate(dri2_dpy->wl_drm, magic);
   }
}

static void
drm_handle_format(void *data, struct wl_drm *drm, uint32_t format)
{
   struct dri2_egl_display *dri2_dpy = data;

   switch (format) {
   case WL_DRM_FORMAT_ARGB8888:
      dri2_dpy->formats |= HAS_ARGB8888;
      break;
   case WL_DRM_FORMAT_XRGB8888:
      dri2_dpy->formats |= HAS_XRGB8888;
      break;
   case WL_DRM_FORMAT_RGB565:
      dri2_dpy->formats |= HAS_RGB565;
      break;
   }
}

static void
drm_handle_capabilities(void *data, struct wl_drm *drm, uint32_t value)
{
   struct dri2_egl_display *dri2_dpy = data;

   dri2_dpy->capabilities = value;
}

static void
drm_handle_authenticated(void *data, struct wl_drm *drm)
{
   struct dri2_egl_display *dri2_dpy = data;

   dri2_dpy->authenticated = 1;
}

static const struct wl_drm_listener drm_listener = {
   .device = drm_handle_device,
   .format = drm_handle_format,
   .authenticated = drm_handle_authenticated,
   .capabilities = drm_handle_capabilities
};

static void
registry_handle_global_drm(void *data, struct wl_registry *registry, uint32_t name,
		       const char *interface, uint32_t version)
{
   struct dri2_egl_display *dri2_dpy = data;

   if (version > 1)
      version = 2;
   if (strcmp(interface, "wl_drm") == 0) {
      dri2_dpy->wl_drm =
         wl_registry_bind(registry, name, &wl_drm_interface, version);
      wl_drm_add_listener(dri2_dpy->wl_drm, &drm_listener, dri2_dpy);
   }
}

static void
registry_handle_global_remove(void *data, struct wl_registry *registry,
			      uint32_t name)
{
}

static const struct wl_registry_listener registry_listener_drm = {
   .global = registry_handle_global_drm,
   .global_remove = registry_handle_global_remove
};

static EGLBoolean
dri2_wl_swap_interval(_EGLDriver *drv,
                   _EGLDisplay *disp,
                   _EGLSurface *surf,
                   EGLint interval)
{
   if (interval > surf->Config->MaxSwapInterval)
      interval = surf->Config->MaxSwapInterval;
   else if (interval < surf->Config->MinSwapInterval)
      interval = surf->Config->MinSwapInterval;

   surf->SwapInterval = interval;

   return EGL_TRUE;
}

static void
dri2_wl_setup_swap_interval(struct dri2_egl_display *dri2_dpy)
{
   GLint vblank_mode = DRI_CONF_VBLANK_DEF_INTERVAL_1;

   /* We can't use values greater than 1 on Wayland because we are using the
    * frame callback to synchronise the frame and the only way we be sure to
    * get a frame callback is to attach a new buffer. Therefore we can't just
    * sit drawing nothing to wait until the next ‘n’ frame callbacks */

   if (dri2_dpy->config)
      dri2_dpy->config->configQueryi(dri2_dpy->dri_screen,
                                     "vblank_mode", &vblank_mode);
   switch (vblank_mode) {
   case DRI_CONF_VBLANK_NEVER:
      dri2_dpy->min_swap_interval = 0;
      dri2_dpy->max_swap_interval = 0;
      dri2_dpy->default_swap_interval = 0;
      break;
   case DRI_CONF_VBLANK_ALWAYS_SYNC:
      dri2_dpy->min_swap_interval = 1;
      dri2_dpy->max_swap_interval = 1;
      dri2_dpy->default_swap_interval = 1;
      break;
   case DRI_CONF_VBLANK_DEF_INTERVAL_0:
      dri2_dpy->min_swap_interval = 0;
      dri2_dpy->max_swap_interval = 1;
      dri2_dpy->default_swap_interval = 0;
      break;
   default:
   case DRI_CONF_VBLANK_DEF_INTERVAL_1:
      dri2_dpy->min_swap_interval = 0;
      dri2_dpy->max_swap_interval = 1;
      dri2_dpy->default_swap_interval = 1;
      break;
   }
}

static struct dri2_egl_display_vtbl dri2_wl_display_vtbl = {
   .authenticate = dri2_wl_authenticate,
   .create_window_surface = dri2_wl_create_window_surface,
   .create_pixmap_surface = dri2_wl_create_pixmap_surface,
   .create_pbuffer_surface = dri2_fallback_create_pbuffer_surface,
   .destroy_surface = dri2_wl_destroy_surface,
   .create_image = dri2_create_image_khr,
   .swap_interval = dri2_wl_swap_interval,
   .swap_buffers = dri2_wl_swap_buffers,
   .swap_buffers_with_damage = dri2_wl_swap_buffers_with_damage,
   .swap_buffers_region = dri2_fallback_swap_buffers_region,
   .post_sub_buffer = dri2_fallback_post_sub_buffer,
   .copy_buffers = dri2_fallback_copy_buffers,
   .query_buffer_age = dri2_wl_query_buffer_age,
   .create_wayland_buffer_from_image = dri2_wl_create_wayland_buffer_from_image,
   .get_sync_values = dri2_fallback_get_sync_values,
   .get_dri_drawable = dri2_surface_get_dri_drawable,
};

static const __DRIextension *dri2_loader_extensions[] = {
   &dri2_loader_extension.base,
   &image_lookup_extension.base,
   &use_invalidate.base,
   NULL,
};

static const __DRIextension *image_loader_extensions[] = {
   &image_loader_extension.base,
   &image_lookup_extension.base,
   &use_invalidate.base,
   NULL,
};

static EGLBoolean
dri2_wl_add_configs_for_visuals(_EGLDriver *drv, _EGLDisplay *disp)
{
   struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
   static const struct {
      const char *format_name;
      int has_format;
      unsigned int rgba_masks[4];
   } visuals[] = {
      { "XRGB8888", HAS_XRGB8888, { 0xff0000, 0xff00, 0x00ff, 0xff000000 } },
      { "ARGB8888", HAS_ARGB8888, { 0xff0000, 0xff00, 0x00ff, 0 } },
      { "RGB565",   HAS_RGB565,   { 0x00f800, 0x07e0, 0x001f, 0 } },
   };
   unsigned int format_count[ARRAY_SIZE(visuals)] = { 0 };
   unsigned int count, i, j;

   count = 0;
   for (i = 0; dri2_dpy->driver_configs[i]; i++) {
      for (j = 0; j < ARRAY_SIZE(visuals); j++) {
         struct dri2_egl_config *dri2_conf;

         if (!(dri2_dpy->formats & visuals[j].has_format))
            continue;

         dri2_conf = dri2_add_config(disp, dri2_dpy->driver_configs[i],
               count + 1, EGL_WINDOW_BIT, NULL, visuals[j].rgba_masks);
         if (dri2_conf) {
            count++;
            format_count[j]++;
         }
      }
   }

   for (i = 0; i < ARRAY_SIZE(format_count); i++) {
      if (!format_count[i]) {
         _eglLog(_EGL_DEBUG, "No DRI config supports native format %s",
                 visuals[i].format_name);
      }
   }

   return (count != 0);
}

static EGLBoolean
dri2_initialize_wayland_drm(_EGLDriver *drv, _EGLDisplay *disp)
{
   struct dri2_egl_display *dri2_dpy;

   loader_set_logger(_eglLog);

   dri2_dpy = calloc(1, sizeof *dri2_dpy);
   if (!dri2_dpy)
      return _eglError(EGL_BAD_ALLOC, "eglInitialize");

   disp->DriverData = (void *) dri2_dpy;
   if (disp->PlatformDisplay == NULL) {
      dri2_dpy->wl_dpy = wl_display_connect(NULL);
      if (dri2_dpy->wl_dpy == NULL)
         goto cleanup_dpy;
      dri2_dpy->own_device = 1;
   } else {
      dri2_dpy->wl_dpy = disp->PlatformDisplay;
   }

   dri2_dpy->wl_queue = wl_display_create_queue(dri2_dpy->wl_dpy);

   if (dri2_dpy->own_device)
      wl_display_dispatch_pending(dri2_dpy->wl_dpy);

   dri2_dpy->wl_registry = wl_display_get_registry(dri2_dpy->wl_dpy);
   wl_proxy_set_queue((struct wl_proxy *) dri2_dpy->wl_registry,
                      dri2_dpy->wl_queue);
   wl_registry_add_listener(dri2_dpy->wl_registry,
                            &registry_listener_drm, dri2_dpy);
   if (roundtrip(dri2_dpy) < 0 || dri2_dpy->wl_drm == NULL)
      goto cleanup_registry;

   if (roundtrip(dri2_dpy) < 0 || dri2_dpy->fd == -1)
      goto cleanup_drm;

   if (roundtrip(dri2_dpy) < 0 || !dri2_dpy->authenticated)
      goto cleanup_fd;

   dri2_dpy->fd = loader_get_user_preferred_fd(dri2_dpy->fd,
                                               &dri2_dpy->is_different_gpu);
   if (dri2_dpy->is_different_gpu) {
      free(dri2_dpy->device_name);
      dri2_dpy->device_name = loader_get_device_name_for_fd(dri2_dpy->fd);
      if (!dri2_dpy->device_name) {
         _eglError(EGL_BAD_ALLOC, "wayland-egl: failed to get device name "
                                  "for requested GPU");
         goto cleanup_fd;
      }
   }

   /* we have to do the check now, because loader_get_user_preferred_fd
    * will return a render-node when the requested gpu is different
    * to the server, but also if the client asks for the same gpu than
    * the server by requesting its pci-id */
   dri2_dpy->is_render_node = drmGetNodeTypeFromFd(dri2_dpy->fd) == DRM_NODE_RENDER;

   dri2_dpy->driver_name = loader_get_driver_for_fd(dri2_dpy->fd);
   if (dri2_dpy->driver_name == NULL) {
      _eglError(EGL_BAD_ALLOC, "DRI2: failed to get driver name");
      goto cleanup_fd;
   }

   if (!dri2_load_driver(disp))
      goto cleanup_driver_name;

   /* render nodes cannot use Gem names, and thus do not support
    * the __DRI_DRI2_LOADER extension */
   if (!dri2_dpy->is_render_node)
      dri2_dpy->loader_extensions = dri2_loader_extensions;
   else
      dri2_dpy->loader_extensions = image_loader_extensions;

   if (!dri2_create_screen(disp))
      goto cleanup_driver;

   dri2_wl_setup_swap_interval(dri2_dpy);

   /* To use Prime, we must have _DRI_IMAGE v7 at least.
    * createImageFromFds support indicates that Prime export/import
    * is supported by the driver. Fall back to
    * gem names if we don't have Prime support. */

   if (dri2_dpy->image->base.version < 7 ||
       dri2_dpy->image->createImageFromFds == NULL)
      dri2_dpy->capabilities &= ~WL_DRM_CAPABILITY_PRIME;

   /* We cannot use Gem names with render-nodes, only prime fds (dma-buf).
    * The server needs to accept them */
   if (dri2_dpy->is_render_node &&
       !(dri2_dpy->capabilities & WL_DRM_CAPABILITY_PRIME)) {
      _eglLog(_EGL_WARNING, "wayland-egl: display is not render-node capable");
      goto cleanup_screen;
   }

   if (dri2_dpy->is_different_gpu &&
       (dri2_dpy->image->base.version < 9 ||
        dri2_dpy->image->blitImage == NULL)) {
      _eglLog(_EGL_WARNING, "wayland-egl: Different GPU selected, but the "
                            "Image extension in the driver is not "
                            "compatible. Version 9 or later and blitImage() "
                            "are required");
      goto cleanup_screen;
   }

   if (!dri2_wl_add_configs_for_visuals(drv, disp)) {
      _eglError(EGL_NOT_INITIALIZED, "DRI2: failed to add configs");
      goto cleanup_screen;
   }

   dri2_set_WL_bind_wayland_display(drv, disp);
   /* When cannot convert EGLImage to wl_buffer when on a different gpu,
    * because the buffer of the EGLImage has likely a tiling mode the server
    * gpu won't support. These is no way to check for now. Thus do not support the
    * extension */
   if (!dri2_dpy->is_different_gpu) {
      disp->Extensions.WL_create_wayland_buffer_from_image = EGL_TRUE;
   } else {
      dri2_wl_display_vtbl.create_wayland_buffer_from_image =
         dri2_fallback_create_wayland_buffer_from_image;
   }
   disp->Extensions.EXT_buffer_age = EGL_TRUE;

   disp->Extensions.EXT_swap_buffers_with_damage = EGL_TRUE;

   /* Fill vtbl last to prevent accidentally calling virtual function during
    * initialization.
    */
   dri2_dpy->vtbl = &dri2_wl_display_vtbl;

   return EGL_TRUE;

 cleanup_screen:
   dri2_dpy->core->destroyScreen(dri2_dpy->dri_screen);
 cleanup_driver:
   dlclose(dri2_dpy->driver);
 cleanup_driver_name:
   free(dri2_dpy->driver_name);
 cleanup_fd:
   close(dri2_dpy->fd);
 cleanup_drm:
   free(dri2_dpy->device_name);
   wl_drm_destroy(dri2_dpy->wl_drm);
 cleanup_registry:
   wl_registry_destroy(dri2_dpy->wl_registry);
   wl_event_queue_destroy(dri2_dpy->wl_queue);
 cleanup_dpy:
   free(dri2_dpy);
   disp->DriverData = NULL;

   return EGL_FALSE;
}

static int
dri2_wl_swrast_get_stride_for_format(int format, int w)
{
   if (format == WL_SHM_FORMAT_RGB565)
      return 2 * w;
   else /* ARGB8888 || XRGB8888 */
      return 4 * w;
}

/*
 * Taken from weston shared/os-compatibility.c
 */

#ifndef HAVE_MKOSTEMP

static int
set_cloexec_or_close(int fd)
{
   long flags;

   if (fd == -1)
      return -1;

   flags = fcntl(fd, F_GETFD);
   if (flags == -1)
      goto err;

   if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) == -1)
      goto err;

   return fd;

err:
   close(fd);
   return -1;
}

#endif

/*
 * Taken from weston shared/os-compatibility.c
 */

static int
create_tmpfile_cloexec(char *tmpname)
{
   int fd;

#ifdef HAVE_MKOSTEMP
   fd = mkostemp(tmpname, O_CLOEXEC);
   if (fd >= 0)
      unlink(tmpname);
#else
   fd = mkstemp(tmpname);
   if (fd >= 0) {
      fd = set_cloexec_or_close(fd);
      unlink(tmpname);
   }
#endif

   return fd;
}

/*
 * Taken from weston shared/os-compatibility.c
 *
 * Create a new, unique, anonymous file of the given size, and
 * return the file descriptor for it. The file descriptor is set
 * CLOEXEC. The file is immediately suitable for mmap()'ing
 * the given size at offset zero.
 *
 * The file should not have a permanent backing store like a disk,
 * but may have if XDG_RUNTIME_DIR is not properly implemented in OS.
 *
 * The file name is deleted from the file system.
 *
 * The file is suitable for buffer sharing between processes by
 * transmitting the file descriptor over Unix sockets using the
 * SCM_RIGHTS methods.
 *
 * If the C library implements posix_fallocate(), it is used to
 * guarantee that disk space is available for the file at the
 * given size. If disk space is insufficent, errno is set to ENOSPC.
 * If posix_fallocate() is not supported, program may receive
 * SIGBUS on accessing mmap()'ed file contents instead.
 */
static int
os_create_anonymous_file(off_t size)
{
   static const char template[] = "/mesa-shared-XXXXXX";
   const char *path;
   char *name;
   int fd;
   int ret;

   path = getenv("XDG_RUNTIME_DIR");
   if (!path) {
      errno = ENOENT;
      return -1;
   }

   name = malloc(strlen(path) + sizeof(template));
   if (!name)
      return -1;

   strcpy(name, path);
   strcat(name, template);

   fd = create_tmpfile_cloexec(name);

   free(name);

   if (fd < 0)
      return -1;

   ret = ftruncate(fd, size);
   if (ret < 0) {
      close(fd);
      return -1;
   }

   return fd;
}


static EGLBoolean
dri2_wl_swrast_allocate_buffer(struct dri2_egl_display *dri2_dpy,
                               int format, int w, int h,
                               void **data, int *size,
                               struct wl_buffer **buffer)
{
   struct wl_shm_pool *pool;
   int fd, stride, size_map;
   void *data_map;

   stride = dri2_wl_swrast_get_stride_for_format(format, w);
   size_map = h * stride;

   /* Create a sharable buffer */
   fd = os_create_anonymous_file(size_map);
   if (fd < 0)
      return EGL_FALSE;

   data_map = mmap(NULL, size_map, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
   if (data_map == MAP_FAILED) {
      close(fd);
      return EGL_FALSE;
   }

   /* Share it in a wl_buffer */
   pool = wl_shm_create_pool(dri2_dpy->wl_shm, fd, size_map);
   *buffer = wl_shm_pool_create_buffer(pool, 0, w, h, stride, format);
   wl_shm_pool_destroy(pool);
   close(fd);

   *data = data_map;
   *size = size_map;
   return EGL_TRUE;
}

static int
swrast_update_buffers(struct dri2_egl_surface *dri2_surf)
{
   struct dri2_egl_display *dri2_dpy =
      dri2_egl_display(dri2_surf->base.Resource.Display);
   int i;

   /* we need to do the following operations only once per frame */
   if (dri2_surf->back)
      return 0;

   if (dri2_surf->base.Width != dri2_surf->wl_win->width ||
       dri2_surf->base.Height != dri2_surf->wl_win->height) {

      dri2_wl_release_buffers(dri2_surf);

      dri2_surf->base.Width  = dri2_surf->wl_win->width;
      dri2_surf->base.Height = dri2_surf->wl_win->height;
      dri2_surf->dx = dri2_surf->wl_win->dx;
      dri2_surf->dy = dri2_surf->wl_win->dy;
      dri2_surf->current = NULL;
   }

   /* find back buffer */

   /* There might be a buffer release already queued that wasn't processed */
   wl_display_dispatch_queue_pending(dri2_dpy->wl_dpy, dri2_dpy->wl_queue);

   /* try get free buffer already created */
   for (i = 0; i < ARRAY_SIZE(dri2_surf->color_buffers); i++) {
      if (!dri2_surf->color_buffers[i].locked &&
          dri2_surf->color_buffers[i].wl_buffer) {
          dri2_surf->back = &dri2_surf->color_buffers[i];
          break;
      }
   }

   /* else choose any another free location */
   if (!dri2_surf->back) {
      for (i = 0; i < ARRAY_SIZE(dri2_surf->color_buffers); i++) {
         if (!dri2_surf->color_buffers[i].locked) {
             dri2_surf->back = &dri2_surf->color_buffers[i];
             if (!dri2_wl_swrast_allocate_buffer(dri2_dpy,
                                                 dri2_surf->format,
                                                 dri2_surf->base.Width,
                                                 dri2_surf->base.Height,
                                                 &dri2_surf->back->data,
                                                 &dri2_surf->back->data_size,
                                                 &dri2_surf->back->wl_buffer)) {
                _eglError(EGL_BAD_ALLOC, "failed to allocate color buffer");
                 return -1;
             }
             wl_proxy_set_queue((struct wl_proxy *) dri2_surf->back->wl_buffer,
                                dri2_dpy->wl_queue);
             wl_buffer_add_listener(dri2_surf->back->wl_buffer,
                                    &wl_buffer_listener, dri2_surf);
             break;
         }
      }
   }

   if (!dri2_surf->back) {
      _eglError(EGL_BAD_ALLOC, "failed to find free buffer");
      return -1;
   }

   dri2_surf->back->locked = 1;

   /* If we have an extra unlocked buffer at this point, we had to do triple
    * buffering for a while, but now can go back to just double buffering.
    * That means we can free any unlocked buffer now. */
   for (i = 0; i < ARRAY_SIZE(dri2_surf->color_buffers); i++) {
      if (!dri2_surf->color_buffers[i].locked &&
          dri2_surf->color_buffers[i].wl_buffer) {
         wl_buffer_destroy(dri2_surf->color_buffers[i].wl_buffer);
         munmap(dri2_surf->color_buffers[i].data,
                dri2_surf->color_buffers[i].data_size);
         dri2_surf->color_buffers[i].wl_buffer = NULL;
         dri2_surf->color_buffers[i].data = NULL;
      }
   }

   return 0;
}

static void*
dri2_wl_swrast_get_frontbuffer_data(struct dri2_egl_surface *dri2_surf)
{
   /* if there has been a resize: */
   if (!dri2_surf->current)
      return NULL;

   return dri2_surf->current->data;
}

static void*
dri2_wl_swrast_get_backbuffer_data(struct dri2_egl_surface *dri2_surf)
{
   assert(dri2_surf->back);
   return dri2_surf->back->data;
}

static void
dri2_wl_swrast_commit_backbuffer(struct dri2_egl_surface *dri2_surf)
{
   struct dri2_egl_display *dri2_dpy = dri2_egl_display(dri2_surf->base.Resource.Display);

   while (dri2_surf->throttle_callback != NULL)
      if (wl_display_dispatch_queue(dri2_dpy->wl_dpy,
                                    dri2_dpy->wl_queue) == -1)
         return;

   if (dri2_surf->base.SwapInterval > 0) {
      dri2_surf->throttle_callback =
         wl_surface_frame(dri2_surf->wl_win->surface);
      wl_callback_add_listener(dri2_surf->throttle_callback,
                               &throttle_listener, dri2_surf);
      wl_proxy_set_queue((struct wl_proxy *) dri2_surf->throttle_callback,
                         dri2_dpy->wl_queue);
   }

   dri2_surf->current = dri2_surf->back;
   dri2_surf->back = NULL;

   wl_surface_attach(dri2_surf->wl_win->surface,
                     dri2_surf->current->wl_buffer,
                     dri2_surf->dx, dri2_surf->dy);

   dri2_surf->wl_win->attached_width  = dri2_surf->base.Width;
   dri2_surf->wl_win->attached_height = dri2_surf->base.Height;
   /* reset resize growing parameters */
   dri2_surf->dx = 0;
   dri2_surf->dy = 0;

   wl_surface_damage(dri2_surf->wl_win->surface,
                     0, 0, INT32_MAX, INT32_MAX);
   wl_surface_commit(dri2_surf->wl_win->surface);

   /* If we're not waiting for a frame callback then we'll at least throttle
    * to a sync callback so that we always give a chance for the compositor to
    * handle the commit and send a release event before checking for a free
    * buffer */
   if (dri2_surf->throttle_callback == NULL) {
      dri2_surf->throttle_callback = wl_display_sync(dri2_dpy->wl_dpy);
      wl_callback_add_listener(dri2_surf->throttle_callback,
                               &throttle_listener, dri2_surf);
      wl_proxy_set_queue((struct wl_proxy *) dri2_surf->throttle_callback,
                         dri2_dpy->wl_queue);
   }

   wl_display_flush(dri2_dpy->wl_dpy);
}

static void
dri2_wl_swrast_get_drawable_info(__DRIdrawable * draw,
                                 int *x, int *y, int *w, int *h,
                                 void *loaderPrivate)
{
   struct dri2_egl_surface *dri2_surf = loaderPrivate;

   (void) swrast_update_buffers(dri2_surf);
   *x = 0;
   *y = 0;
   *w = dri2_surf->base.Width;
   *h = dri2_surf->base.Height;
}

static void
dri2_wl_swrast_get_image(__DRIdrawable * read,
                         int x, int y, int w, int h,
                         char *data, void *loaderPrivate)
{
   struct dri2_egl_surface *dri2_surf = loaderPrivate;
   int copy_width = dri2_wl_swrast_get_stride_for_format(dri2_surf->format, w);
   int x_offset = dri2_wl_swrast_get_stride_for_format(dri2_surf->format, x);
   int src_stride = dri2_wl_swrast_get_stride_for_format(dri2_surf->format, dri2_surf->base.Width);
   int dst_stride = copy_width;
   char *src, *dst;

   src = dri2_wl_swrast_get_frontbuffer_data(dri2_surf);
   if (!src) {
      memset(data, 0, copy_width * h);
      return;
   }

   assert(data != src);
   assert(copy_width <= src_stride);

   src += x_offset;
   src += y * src_stride;
   dst = data;

   if (copy_width > src_stride-x_offset)
      copy_width = src_stride-x_offset;
   if (h > dri2_surf->base.Height-y)
      h = dri2_surf->base.Height-y;

   for (; h>0; h--) {
      memcpy(dst, src, copy_width);
      src += src_stride;
      dst += dst_stride;
   }
}

static void
dri2_wl_swrast_put_image2(__DRIdrawable * draw, int op,
                         int x, int y, int w, int h, int stride,
                         char *data, void *loaderPrivate)
{
   struct dri2_egl_surface *dri2_surf = loaderPrivate;
   int copy_width = dri2_wl_swrast_get_stride_for_format(dri2_surf->format, w);
   int dst_stride = dri2_wl_swrast_get_stride_for_format(dri2_surf->format, dri2_surf->base.Width);
   int x_offset = dri2_wl_swrast_get_stride_for_format(dri2_surf->format, x);
   char *src, *dst;

   assert(copy_width <= stride);

   (void) swrast_update_buffers(dri2_surf);
   dst = dri2_wl_swrast_get_backbuffer_data(dri2_surf);

   /* partial copy, copy old content */
   if (copy_width < dst_stride)
      dri2_wl_swrast_get_image(draw, 0, 0,
                               dri2_surf->base.Width, dri2_surf->base.Height,
                               dst, loaderPrivate);

   dst += x_offset;
   dst += y * dst_stride;

   src = data;

   /* drivers expect we do these checks (and some rely on it) */
   if (copy_width > dst_stride-x_offset)
      copy_width = dst_stride-x_offset;
   if (h > dri2_surf->base.Height-y)
      h = dri2_surf->base.Height-y;

   for (; h>0; h--) {
      memcpy(dst, src, copy_width);
      src += stride;
      dst += dst_stride;
   }
   dri2_wl_swrast_commit_backbuffer(dri2_surf);
}

static void
dri2_wl_swrast_put_image(__DRIdrawable * draw, int op,
                         int x, int y, int w, int h,
                         char *data, void *loaderPrivate)
{
   struct dri2_egl_surface *dri2_surf = loaderPrivate;
   int stride;

   stride = dri2_wl_swrast_get_stride_for_format(dri2_surf->format, w);
   dri2_wl_swrast_put_image2(draw, op, x, y, w, h,
                             stride, data, loaderPrivate);
}

/**
 * Called via eglCreateWindowSurface(), drv->API.CreateWindowSurface().
 */
static _EGLSurface *
dri2_wl_swrast_create_window_surface(_EGLDriver *drv, _EGLDisplay *disp,
                                     _EGLConfig *conf, void *native_window,
                                     const EGLint *attrib_list)
{
   struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
   struct dri2_egl_config *dri2_conf = dri2_egl_config(conf);
   struct wl_egl_window *window = native_window;
   struct dri2_egl_surface *dri2_surf;
   const __DRIconfig *config;

   (void) drv;

   dri2_surf = calloc(1, sizeof *dri2_surf);
   if (!dri2_surf) {
      _eglError(EGL_BAD_ALLOC, "dri2_create_surface");
      return NULL;
   }

   if (!_eglInitSurface(&dri2_surf->base, disp, EGL_WINDOW_BIT, conf, attrib_list))
      goto cleanup_surf;

   if (conf->RedSize == 5)
      dri2_surf->format = WL_SHM_FORMAT_RGB565;
   else if (conf->AlphaSize == 0)
      dri2_surf->format = WL_SHM_FORMAT_XRGB8888;
   else
      dri2_surf->format = WL_SHM_FORMAT_ARGB8888;

   dri2_surf->wl_win = window;

   dri2_surf->base.Width = -1;
   dri2_surf->base.Height = -1;

   config = dri2_get_dri_config(dri2_conf, EGL_WINDOW_BIT,
                                dri2_surf->base.GLColorspace);

   dri2_surf->dri_drawable =
      (*dri2_dpy->swrast->createNewDrawable)(dri2_dpy->dri_screen,
                                             config, dri2_surf);
   if (dri2_surf->dri_drawable == NULL) {
      _eglError(EGL_BAD_ALLOC, "swrast->createNewDrawable");
      goto cleanup_surf;
   }

   dri2_wl_swap_interval(drv, disp, &dri2_surf->base,
                         dri2_dpy->default_swap_interval);

   return &dri2_surf->base;

 cleanup_surf:
   free(dri2_surf);

   return NULL;
}

static EGLBoolean
dri2_wl_swrast_swap_buffers(_EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *draw)
{
   struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
   struct dri2_egl_surface *dri2_surf = dri2_egl_surface(draw);

   dri2_dpy->core->swapBuffers(dri2_surf->dri_drawable);
   return EGL_TRUE;
}

static void
shm_handle_format(void *data, struct wl_shm *shm, uint32_t format)
{
   struct dri2_egl_display *dri2_dpy = data;

   switch (format) {
   case WL_SHM_FORMAT_ARGB8888:
      dri2_dpy->formats |= HAS_ARGB8888;
      break;
   case WL_SHM_FORMAT_XRGB8888:
      dri2_dpy->formats |= HAS_XRGB8888;
      break;
   case WL_SHM_FORMAT_RGB565:
      dri2_dpy->formats |= HAS_RGB565;
      break;
   }
}

static const struct wl_shm_listener shm_listener = {
   .format = shm_handle_format
};

static void
registry_handle_global_swrast(void *data, struct wl_registry *registry, uint32_t name,
                              const char *interface, uint32_t version)
{
   struct dri2_egl_display *dri2_dpy = data;

   if (strcmp(interface, "wl_shm") == 0) {
      dri2_dpy->wl_shm =
         wl_registry_bind(registry, name, &wl_shm_interface, 1);
      wl_shm_add_listener(dri2_dpy->wl_shm, &shm_listener, dri2_dpy);
   }
}

static const struct wl_registry_listener registry_listener_swrast = {
   .global = registry_handle_global_swrast,
   .global_remove = registry_handle_global_remove
};

static struct dri2_egl_display_vtbl dri2_wl_swrast_display_vtbl = {
   .authenticate = NULL,
   .create_window_surface = dri2_wl_swrast_create_window_surface,
   .create_pixmap_surface = dri2_wl_create_pixmap_surface,
   .create_pbuffer_surface = dri2_fallback_create_pbuffer_surface,
   .destroy_surface = dri2_wl_destroy_surface,
   .create_image = dri2_fallback_create_image_khr,
   .swap_interval = dri2_wl_swap_interval,
   .swap_buffers = dri2_wl_swrast_swap_buffers,
   .swap_buffers_with_damage = dri2_fallback_swap_buffers_with_damage,
   .swap_buffers_region = dri2_fallback_swap_buffers_region,
   .post_sub_buffer = dri2_fallback_post_sub_buffer,
   .copy_buffers = dri2_fallback_copy_buffers,
   .query_buffer_age = dri2_fallback_query_buffer_age,
   .create_wayland_buffer_from_image = dri2_fallback_create_wayland_buffer_from_image,
   .get_sync_values = dri2_fallback_get_sync_values,
   .get_dri_drawable = dri2_surface_get_dri_drawable,
};

static const __DRIswrastLoaderExtension swrast_loader_extension = {
   .base = { __DRI_SWRAST_LOADER, 2 },

   .getDrawableInfo = dri2_wl_swrast_get_drawable_info,
   .putImage        = dri2_wl_swrast_put_image,
   .getImage        = dri2_wl_swrast_get_image,
   .putImage2       = dri2_wl_swrast_put_image2,
};

static const __DRIextension *swrast_loader_extensions[] = {
   &swrast_loader_extension.base,
   NULL,
};

static EGLBoolean
dri2_initialize_wayland_swrast(_EGLDriver *drv, _EGLDisplay *disp)
{
   struct dri2_egl_display *dri2_dpy;

   loader_set_logger(_eglLog);

   dri2_dpy = calloc(1, sizeof *dri2_dpy);
   if (!dri2_dpy)
      return _eglError(EGL_BAD_ALLOC, "eglInitialize");

   disp->DriverData = (void *) dri2_dpy;
   if (disp->PlatformDisplay == NULL) {
      dri2_dpy->wl_dpy = wl_display_connect(NULL);
      if (dri2_dpy->wl_dpy == NULL)
         goto cleanup_dpy;
      dri2_dpy->own_device = 1;
   } else {
      dri2_dpy->wl_dpy = disp->PlatformDisplay;
   }

   dri2_dpy->wl_queue = wl_display_create_queue(dri2_dpy->wl_dpy);

   if (dri2_dpy->own_device)
      wl_display_dispatch_pending(dri2_dpy->wl_dpy);

   dri2_dpy->wl_registry = wl_display_get_registry(dri2_dpy->wl_dpy);
   wl_proxy_set_queue((struct wl_proxy *) dri2_dpy->wl_registry,
                      dri2_dpy->wl_queue);
   wl_registry_add_listener(dri2_dpy->wl_registry,
                            &registry_listener_swrast, dri2_dpy);

   if (roundtrip(dri2_dpy) < 0 || dri2_dpy->wl_shm == NULL)
      goto cleanup_registry;

   if (roundtrip(dri2_dpy) < 0 || dri2_dpy->formats == 0)
      goto cleanup_shm;

   dri2_dpy->fd = -1;
   dri2_dpy->driver_name = strdup("swrast");
   if (!dri2_load_driver_swrast(disp))
      goto cleanup_shm;

   dri2_dpy->loader_extensions = swrast_loader_extensions;

   if (!dri2_create_screen(disp))
      goto cleanup_driver;

   dri2_wl_setup_swap_interval(dri2_dpy);

   if (!dri2_wl_add_configs_for_visuals(drv, disp)) {
      _eglError(EGL_NOT_INITIALIZED, "DRI2: failed to add configs");
      goto cleanup_screen;
   }

   /* Fill vtbl last to prevent accidentally calling virtual function during
    * initialization.
    */
   dri2_dpy->vtbl = &dri2_wl_swrast_display_vtbl;

   return EGL_TRUE;

 cleanup_screen:
   dri2_dpy->core->destroyScreen(dri2_dpy->dri_screen);
 cleanup_driver:
   dlclose(dri2_dpy->driver);
 cleanup_shm:
   wl_shm_destroy(dri2_dpy->wl_shm);
 cleanup_registry:
   wl_registry_destroy(dri2_dpy->wl_registry);
   wl_event_queue_destroy(dri2_dpy->wl_queue);
 cleanup_dpy:
   free(dri2_dpy);
   disp->DriverData = NULL;

   return EGL_FALSE;
}

EGLBoolean
dri2_initialize_wayland(_EGLDriver *drv, _EGLDisplay *disp)
{
   EGLBoolean initialized = EGL_TRUE;

   int hw_accel = (getenv("LIBGL_ALWAYS_SOFTWARE") == NULL);

   if (hw_accel) {
      if (!dri2_initialize_wayland_drm(drv, disp)) {
         initialized = dri2_initialize_wayland_swrast(drv, disp);
      }
   } else {
      initialized = dri2_initialize_wayland_swrast(drv, disp);
   }

   return initialized;

}
