gl-renderer: add dmabuf import

Import dmabuf as an EGLImage, and hold on to the EGLImage until we are
signalled a content change. On content change, destroy the EGLImage and
re-import to trigger GPU cache flushes.

We hold on to the EGLImage as long as possible just in case the client
does other imports that might later make re-importing fail.

As dmabuf protocol uses drm_fourcc codes, we need libdrm for
drm_fourcc.h. However, we are not doing any libdrm function calls, so
there is no new need to link to libdrm.

RFCv1 changes:
- fix error if dmabuf exposed unsupported
- always use GL_TEXTURE_EXTERNAL_OES with dmabuf

v2 changes:
- improve support check and error handling
- hold on to the imported EGLImage to avoid the dmabuf becoming
  unimportable in the future
- send internal errors with linux_dmabuf_buffer_send_server_error()
- import EGL_EXT_image_dma_buf_import extension headers
- use heuristics to decide between GL_TEXTURE_2D and
  GL_TEXTURE_EXTERNAL_OES
- add comment about Mesa requirements
- change y-invert from per-plane boolean to per-buffer flag

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Signed-off-by: Louis-Francis Ratté-Boulianne <lfrb@collabora.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>

4 files changed, 251 insertions, 0 deletions

diff --git a/Makefile.am b/Makefile.am
index 9c1cf258..f50587e1 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -205,6 +205,7 @@ gl_renderer_la_LIBADD = $(COMPOSITOR_LIBS) $(EGL_LIBS)
 gl_renderer_la_CFLAGS =				\
 	$(COMPOSITOR_CFLAGS)			\
 	$(EGL_CFLAGS)				\
+	$(GL_RENDERER_CFLAGS)			\
 	$(AM_CFLAGS)
 gl_renderer_la_SOURCES =			\
 	src/gl-renderer.h			\
diff --git a/configure.ac b/configure.ac
index e5bbc0d7..6c77826a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -87,6 +87,7 @@ if test x$enable_egl = xyes; then
 	AC_DEFINE([ENABLE_EGL], [1], [Build Weston with EGL support])
 	PKG_CHECK_MODULES(EGL, [egl >= 7.10 glesv2])
         PKG_CHECK_MODULES([EGL_TESTS], [egl >= 7.10 glesv2 wayland-client wayland-egl])
+	PKG_CHECK_MODULES([GL_RENDERER], [libdrm])
 fi
 
 AC_ARG_ENABLE(xkbcommon,
diff --git a/src/gl-renderer.c b/src/gl-renderer.c
index 4c7137dc..fd0720e2 100644
--- a/src/gl-renderer.c
+++ b/src/gl-renderer.c
@@ -36,9 +36,12 @@
 #include <float.h>
 #include <assert.h>
 #include <linux/input.h>
+#include <drm_fourcc.h>
 
 #include "gl-renderer.h"
 #include "vertex-clipping.h"
+#include "linux-dmabuf.h"
+#include "linux-dmabuf-server-protocol.h"
 
 #include "shared/helpers.h"
 #include "weston-egl-ext.h"
@@ -96,6 +99,10 @@ struct egl_image {
 	struct gl_renderer *renderer;
 	EGLImageKHR image;
 	int refcount;
+
+	/* Only used for dmabuf imported buffer */
+	struct linux_dmabuf_buffer *dmabuf;
+	struct wl_list link;
 };
 
 struct gl_surface_state {
@@ -166,6 +173,9 @@ struct gl_renderer {
 
 	int has_configless_context;
 
+	int has_dmabuf_import;
+	struct wl_list dmabuf_images;
+
 	struct gl_shader texture_shader_rgba;
 	struct gl_shader texture_shader_rgbx;
 	struct gl_shader texture_shader_egl_external;
@@ -212,6 +222,7 @@ egl_image_create(struct gl_renderer *gr, EGLenum target,
 	struct egl_image *img;
 
 	img = zalloc(sizeof *img);
+	wl_list_init(&img->link);
 	img->renderer = gr;
 	img->refcount = 1;
 	img->image = gr->create_image(gr->egl_display, EGL_NO_CONTEXT,
@@ -244,7 +255,11 @@ egl_image_unref(struct egl_image *image)
 	if (image->refcount > 0)
 		return image->refcount;
 
+	if (image->dmabuf)
+		linux_dmabuf_buffer_set_user_data(image->dmabuf, NULL, NULL);
+
 	gr->destroy_image(gr->egl_display, image->image);
+	wl_list_remove(&image->link);
 	free(image);
 
 	return 0;
@@ -1403,12 +1418,210 @@ gl_renderer_attach_egl(struct weston_surface *es, struct weston_buffer *buffer,
 }
 
 static void
+gl_renderer_destroy_dmabuf(struct linux_dmabuf_buffer *dmabuf)
+{
+	struct egl_image *image = dmabuf->user_data;
+
+	egl_image_unref(image);
+}
+
+static struct egl_image *
+import_dmabuf(struct gl_renderer *gr,
+	      struct linux_dmabuf_buffer *dmabuf)
+{
+	struct egl_image *image;
+	EGLint attribs[30];
+	int atti = 0;
+
+	image = linux_dmabuf_buffer_get_user_data(dmabuf);
+	if (image)
+		return egl_image_ref(image);
+
+	/* This requires the Mesa commit in
+	 * Mesa 10.3 (08264e5dad4df448e7718e782ad9077902089a07) or
+	 * Mesa 10.2.7 (55d28925e6109a4afd61f109e845a8a51bd17652).
+	 * Otherwise Mesa closes the fd behind our back and re-importing
+	 * will fail.
+	 * https://bugs.freedesktop.org/show_bug.cgi?id=76188
+	 */
+
+	attribs[atti++] = EGL_WIDTH;
+	attribs[atti++] = dmabuf->width;
+	attribs[atti++] = EGL_HEIGHT;
+	attribs[atti++] = dmabuf->height;
+	attribs[atti++] = EGL_LINUX_DRM_FOURCC_EXT;
+	attribs[atti++] = dmabuf->format;
+	/* XXX: Add modifier here when supported */
+
+	if (dmabuf->n_planes > 0) {
+		attribs[atti++] = EGL_DMA_BUF_PLANE0_FD_EXT;
+		attribs[atti++] = dmabuf->dmabuf_fd[0];
+		attribs[atti++] = EGL_DMA_BUF_PLANE0_OFFSET_EXT;
+		attribs[atti++] = dmabuf->offset[0];
+		attribs[atti++] = EGL_DMA_BUF_PLANE0_PITCH_EXT;
+		attribs[atti++] = dmabuf->stride[0];
+	}
+
+	if (dmabuf->n_planes > 1) {
+		attribs[atti++] = EGL_DMA_BUF_PLANE1_FD_EXT;
+		attribs[atti++] = dmabuf->dmabuf_fd[1];
+		attribs[atti++] = EGL_DMA_BUF_PLANE1_OFFSET_EXT;
+		attribs[atti++] = dmabuf->offset[1];
+		attribs[atti++] = EGL_DMA_BUF_PLANE1_PITCH_EXT;
+		attribs[atti++] = dmabuf->stride[1];
+	}
+
+	if (dmabuf->n_planes > 2) {
+		attribs[atti++] = EGL_DMA_BUF_PLANE2_FD_EXT;
+		attribs[atti++] = dmabuf->dmabuf_fd[2];
+		attribs[atti++] = EGL_DMA_BUF_PLANE2_OFFSET_EXT;
+		attribs[atti++] = dmabuf->offset[2];
+		attribs[atti++] = EGL_DMA_BUF_PLANE2_PITCH_EXT;
+		attribs[atti++] = dmabuf->stride[2];
+	}
+
+	attribs[atti++] = EGL_NONE;
+
+	image = egl_image_create(gr, EGL_LINUX_DMA_BUF_EXT, NULL,
+				 attribs);
+
+	if (!image)
+		return NULL;
+
+	/* The cache owns one ref. The caller gets another. */
+	image->dmabuf = dmabuf;
+	wl_list_insert(&gr->dmabuf_images, &image->link);
+	linux_dmabuf_buffer_set_user_data(dmabuf, egl_image_ref(image),
+		gl_renderer_destroy_dmabuf);
+
+	return image;
+}
+
+static bool
+gl_renderer_import_dmabuf(struct weston_compositor *ec,
+			  struct linux_dmabuf_buffer *dmabuf)
+{
+	struct gl_renderer *gr = get_renderer(ec);
+	struct egl_image *image;
+	int i;
+
+	assert(gr->has_dmabuf_import);
+
+	for (i = 0; i < dmabuf->n_planes; i++) {
+		/* EGL import does not have modifiers */
+		if (dmabuf->modifier[i] != 0)
+			return false;
+	}
+
+	/* reject all flags we do not recognize or handle */
+	if (dmabuf->flags & ~ZLINUX_BUFFER_PARAMS_FLAGS_Y_INVERT)
+		return false;
+
+	image = import_dmabuf(gr, dmabuf);
+	if (!image)
+		return false;
+
+	/* Cache retains a ref. */
+	egl_image_unref(image);
+
+	return true;
+}
+
+static GLenum
+choose_texture_target(struct linux_dmabuf_buffer *dmabuf)
+{
+	if (dmabuf->n_planes > 1)
+		return GL_TEXTURE_EXTERNAL_OES;
+
+	switch (dmabuf->format & ~DRM_FORMAT_BIG_ENDIAN) {
+	case DRM_FORMAT_YUYV:
+	case DRM_FORMAT_YVYU:
+	case DRM_FORMAT_UYVY:
+	case DRM_FORMAT_VYUY:
+	case DRM_FORMAT_AYUV:
+		return GL_TEXTURE_EXTERNAL_OES;
+	default:
+		return GL_TEXTURE_2D;
+	}
+}
+
+static void
+gl_renderer_attach_dmabuf(struct weston_surface *surface,
+			  struct weston_buffer *buffer,
+			  struct linux_dmabuf_buffer *dmabuf)
+{
+	struct gl_renderer *gr = get_renderer(surface->compositor);
+	struct gl_surface_state *gs = get_surface_state(surface);
+	int i;
+
+	if (!gr->has_dmabuf_import) {
+		linux_dmabuf_buffer_send_server_error(dmabuf,
+				"EGL dmabuf import not supported");
+		return;
+	}
+
+	buffer->width = dmabuf->width;
+	buffer->height = dmabuf->height;
+	buffer->y_inverted =
+		!!(dmabuf->flags & ZLINUX_BUFFER_PARAMS_FLAGS_Y_INVERT);
+
+	for (i = 0; i < gs->num_images; i++)
+		egl_image_unref(gs->images[i]);
+	gs->num_images = 0;
+
+	gs->target = choose_texture_target(dmabuf);
+	switch (gs->target) {
+	case GL_TEXTURE_2D:
+		gs->shader = &gr->texture_shader_rgba;
+		break;
+	default:
+		gs->shader = &gr->texture_shader_egl_external;
+	}
+
+	/*
+	 * We try to always hold an imported EGLImage from the dmabuf
+	 * to prevent the client from preventing re-imports. But, we also
+	 * need to re-import every time the contents may change because
+	 * GL driver's caching may need flushing.
+	 *
+	 * Here we release the cache reference which has to be final.
+	 */
+	gs->images[0] = linux_dmabuf_buffer_get_user_data(dmabuf);
+	if (gs->images[0]) {
+		int ret;
+
+		ret = egl_image_unref(gs->images[0]);
+		assert(ret == 0);
+	}
+
+	gs->images[0] = import_dmabuf(gr, dmabuf);
+	if (!gs->images[0]) {
+		linux_dmabuf_buffer_send_server_error(dmabuf,
+				"EGL dmabuf import failed");
+		return;
+	}
+	gs->num_images = 1;
+
+	ensure_textures(gs, 1);
+
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(gs->target, gs->textures[0]);
+	gr->image_target_texture_2d(gs->target, gs->images[0]->image);
+
+	gs->pitch = buffer->width;
+	gs->height = buffer->height;
+	gs->buffer_type = BUFFER_TYPE_EGL;
+	gs->y_inverted = buffer->y_inverted;
+}
+
+static void
 gl_renderer_attach(struct weston_surface *es, struct weston_buffer *buffer)
 {
 	struct weston_compositor *ec = es->compositor;
 	struct gl_renderer *gr = get_renderer(ec);
 	struct gl_surface_state *gs = get_surface_state(es);
 	struct wl_shm_buffer *shm_buffer;
+	struct linux_dmabuf_buffer *dmabuf;
 	EGLint format;
 	int i;
 
@@ -1434,6 +1647,8 @@ gl_renderer_attach(struct weston_surface *es, struct weston_buffer *buffer)
 	else if (gr->query_buffer(gr->egl_display, (void *) buffer->resource,
 				  EGL_TEXTURE_FORMAT, &format))
 		gl_renderer_attach_egl(es, buffer, format);
+	else if ((dmabuf = linux_dmabuf_buffer_get(buffer->resource)))
+		gl_renderer_attach_dmabuf(es, buffer, dmabuf);
 	else {
 		weston_log("unhandled buffer type!\n");
 		weston_buffer_reference(&gs->buffer_ref, NULL);
@@ -2155,6 +2370,7 @@ static void
 gl_renderer_destroy(struct weston_compositor *ec)
 {
 	struct gl_renderer *gr = get_renderer(ec);
+	struct egl_image *image, *next;
 
 	wl_signal_emit(&gr->destroy_signal, gr);
 
@@ -2166,6 +2382,14 @@ gl_renderer_destroy(struct weston_compositor *ec)
 		       EGL_NO_SURFACE, EGL_NO_SURFACE,
 		       EGL_NO_CONTEXT);
 
+
+	wl_list_for_each_safe(image, next, &gr->dmabuf_images, link) {
+		int ret;
+
+		ret = egl_image_unref(image);
+		assert(ret == 0);
+	}
+
 	eglTerminate(gr->egl_display);
 	eglReleaseThread();
 
@@ -2249,6 +2473,11 @@ gl_renderer_setup_egl_extensions(struct weston_compositor *ec)
 		gr->has_configless_context = 1;
 #endif
 
+#ifdef EGL_EXT_image_dma_buf_import
+	if (strstr(extensions, "EGL_EXT_image_dma_buf_import"))
+		gr->has_dmabuf_import = 1;
+#endif
+
 	renderer_setup_egl_client_extensions(gr);
 
 	return 0;
@@ -2431,6 +2660,10 @@ gl_renderer_create(struct weston_compositor *ec, EGLenum platform,
 	if (gl_renderer_setup_egl_extensions(ec) < 0)
 		goto fail_with_error;
 
+	wl_list_init(&gr->dmabuf_images);
+	if (gr->has_dmabuf_import)
+		gr->base.import_dmabuf = gl_renderer_import_dmabuf;
+
 	wl_display_add_shm_format(ec->wl_display, WL_SHM_FORMAT_RGB565);
 
 	wl_signal_init(&gr->destroy_signal);
diff --git a/src/weston-egl-ext.h b/src/weston-egl-ext.h
index d08ca5b7..32f6108f 100644
--- a/src/weston-egl-ext.h
+++ b/src/weston-egl-ext.h
@@ -100,5 +100,21 @@ typedef struct wl_buffer * (EGLAPIENTRYP PFNEGLCREATEWAYLANDBUFFERFROMIMAGEWL) (
 #define GL_UNPACK_SKIP_PIXELS_EXT                               0x0CF4
 #endif
 
+/* Define needed tokens from EGL_EXT_image_dma_buf_import extension
+ * here to avoid having to add ifdefs everywhere.*/
+#ifndef EGL_EXT_image_dma_buf_import
+#define EGL_LINUX_DMA_BUF_EXT					0x3270
+#define EGL_LINUX_DRM_FOURCC_EXT				0x3271
+#define EGL_DMA_BUF_PLANE0_FD_EXT				0x3272
+#define EGL_DMA_BUF_PLANE0_OFFSET_EXT				0x3273
+#define EGL_DMA_BUF_PLANE0_PITCH_EXT				0x3274
+#define EGL_DMA_BUF_PLANE1_FD_EXT				0x3275
+#define EGL_DMA_BUF_PLANE1_OFFSET_EXT				0x3276
+#define EGL_DMA_BUF_PLANE1_PITCH_EXT				0x3277
+#define EGL_DMA_BUF_PLANE2_FD_EXT				0x3278
+#define EGL_DMA_BUF_PLANE2_OFFSET_EXT				0x3279
+#define EGL_DMA_BUF_PLANE2_PITCH_EXT				0x327A
+#endif
+
 
 #endif