loader: Add dri3 helper

v2: From Martin Peres
 - Try to fit in the 80-col limit as much as possible

v3: From Martin Peres
 - introduce loader_dri3_helper.la to avoid dragging the xcb dep everywhere (Kristian & Emil)
 - get rid of the width, height, dri_screen and is_different_gpu vfuncs (Kristian)
 - replace the create/destroy functions with init/fini for dri3 drawables
 - prefix static functions with dri3_ and exported ones with loader_dri3 (Emil)
 - keep the function definition consistent (Emil)

Signed-off-by: Boyan Ding <boyan.j.ding@gmail.com>
Signed-off-by: Martin Peres <martin.peres@linux.intel.com>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>
Reviewed-by: Emil Velikov <emil.velikov@collabora.co.uk>

configure.ac

@@ -1226,7 +1226,8 @@ xyesno)
 
             if test x"$enable_dri3" = xyes; then
                PKG_CHECK_EXISTS([xcb >= $XCB_REQUIRED], [], AC_MSG_ERROR([DRI3 requires xcb >= $XCB_REQUIRED]))
-               dri_modules="$dri_modules xcb-dri3 xcb-present xcb-sync xshmfence >= $XSHMFENCE_REQUIRED"
+               dri3_modules="xcb-dri3 xcb-present xcb-sync xshmfence >= $XSHMFENCE_REQUIRED"
+               PKG_CHECK_MODULES([XCB_DRI3], [$dri3_modules])
             fi
         fi
         if test x"$dri_platform" = xapple ; then

src/glx/Makefile.am

@@ -133,6 +133,8 @@ if HAVE_DRI3
 libglx_la_SOURCES += \
 	dri3_glx.c \
 	dri3_priv.h
+
+libglx_la_LIBADD += $(XCB_DRI3_LIBS)
 endif
 
 if HAVE_APPLEDRI

src/loader/Makefile.am

@@ -23,7 +23,7 @@ include Makefile.sources
 
 EXTRA_DIST = SConscript
 
-noinst_LTLIBRARIES = libloader.la
+noinst_LTLIBRARIES = libloader.la libloader_dri3_helper.la
 
 libloader_la_CPPFLAGS = \
 	$(DEFINES) \
@@ -55,3 +55,16 @@ libloader_la_CPPFLAGS += \
 libloader_la_LIBADD += \
 	$(LIBDRM_LIBS)
 endif
+
+if HAVE_DRI3
+libloader_dri3_helper_la_CPPFLAGS = \
+	$(DEFINES) \
+	-I$(top_srcdir)/include \
+	-I$(top_srcdir)/src \
+	$(LIBDRM_CFLAGS)
+
+libloader_dri3_helper_la_SOURCES = \
+	loader_dri3_helper.c \
+	loader_dri3_helper.h
+libloader_dri3_helper_la_LIBADD = $(XCB_DRI3_LIBS)
+endif

src/loader/loader_dri3_helper.h

@@ -0,0 +1,232 @@
+/*
+ * Copyright © 2013 Keith Packard
+ * Copyright © 2015 Boyan Ding
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#ifndef LOADER_DRI3_HEADER_H
+#define LOADER_DRI3_HEADER_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <xcb/xcb.h>
+#include <xcb/present.h>
+
+#include <GL/gl.h>
+#include <GL/internal/dri_interface.h>
+
+enum loader_dri3_buffer_type {
+   loader_dri3_buffer_back = 0,
+   loader_dri3_buffer_front = 1
+};
+
+struct loader_dri3_buffer {
+   __DRIimage   *image;
+   __DRIimage   *linear_buffer;
+   uint32_t     pixmap;
+
+   /* Synchronization between the client and X server is done using an
+    * xshmfence that is mapped into an X server SyncFence. This lets the
+    * client check whether the X server is done using a buffer with a simple
+    * xshmfence call, rather than going to read X events from the wire.
+    *
+    * However, we can only wait for one xshmfence to be triggered at a time,
+    * so we need to know *which* buffer is going to be idle next. We do that
+    * by waiting for a PresentIdleNotify event. When that event arrives, the
+    * 'busy' flag gets cleared and the client knows that the fence has been
+    * triggered, and that the wait call will not block.
+    */
+
+   uint32_t     sync_fence;     /* XID of X SyncFence object */
+   struct xshmfence *shm_fence; /* pointer to xshmfence object */
+   bool         busy;           /* Set on swap, cleared on IdleNotify */
+   bool         own_pixmap;     /* We allocated the pixmap ID, free on destroy */
+
+   uint32_t     size;
+   uint32_t     pitch;
+   uint32_t     cpp;
+   uint32_t     flags;
+   uint32_t     width, height;
+   uint64_t     last_swap;
+
+   enum loader_dri3_buffer_type        buffer_type;
+};
+
+
+#define LOADER_DRI3_MAX_BACK   4
+#define LOADER_DRI3_BACK_ID(i) (i)
+#define LOADER_DRI3_FRONT_ID   (LOADER_DRI3_MAX_BACK)
+
+static inline int
+loader_dri3_pixmap_buf_id(enum loader_dri3_buffer_type buffer_type)
+{
+   if (buffer_type == loader_dri3_buffer_back)
+      return LOADER_DRI3_BACK_ID(0);
+   else
+      return LOADER_DRI3_FRONT_ID;
+}
+
+struct loader_dri3_extensions {
+   const __DRIcoreExtension *core;
+   const __DRIimageDriverExtension *image_driver;
+   const __DRI2flushExtension *flush;
+   const __DRI2configQueryExtension *config;
+   const __DRItexBufferExtension *tex_buffer;
+   const __DRIimageExtension *image;
+};
+
+struct loader_dri3_drawable;
+
+struct loader_dri3_vtable {
+   int (*get_swap_interval)(struct loader_dri3_drawable *);
+   int (*clamp_swap_interval)(struct loader_dri3_drawable *, int);
+   void (*set_swap_interval)(struct loader_dri3_drawable *, int);
+   void (*set_drawable_size)(struct loader_dri3_drawable *, int, int);
+   bool (*in_current_context)(struct loader_dri3_drawable *);
+   __DRIcontext *(*get_dri_context)(struct loader_dri3_drawable *);
+   void (*flush_drawable)(struct loader_dri3_drawable *, unsigned);
+   void (*show_fps)(struct loader_dri3_drawable *, uint64_t);
+};
+
+#define LOADER_DRI3_NUM_BUFFERS (1 + LOADER_DRI3_MAX_BACK)
+
+struct loader_dri3_drawable {
+   xcb_connection_t *conn;
+   __DRIdrawable *dri_drawable;
+   xcb_drawable_t drawable;
+   int width;
+   int height;
+   int depth;
+   uint8_t have_back;
+   uint8_t have_fake_front;
+   uint8_t is_pixmap;
+   uint8_t flipping;
+
+   /* Information about the GPU owning the buffer */
+   __DRIscreen *dri_screen;
+   bool is_different_gpu;
+
+   /* Present extension capabilities
+    */
+   uint32_t present_capabilities;
+
+   /* SBC numbers are tracked by using the serial numbers
+    * in the present request and complete events
+    */
+   uint64_t send_sbc;
+   uint64_t recv_sbc;
+
+   /* Last received UST/MSC values for pixmap present complete */
+   uint64_t ust, msc;
+
+   /* Last received UST/MSC values from present notify msc event */
+   uint64_t notify_ust, notify_msc;
+
+   /* Serial numbers for tracking wait_for_msc events */
+   uint32_t send_msc_serial;
+   uint32_t recv_msc_serial;
+
+   struct loader_dri3_buffer *buffers[LOADER_DRI3_NUM_BUFFERS];
+   int cur_back;
+   int num_back;
+
+   uint32_t *stamp;
+
+   xcb_present_event_t eid;
+   xcb_gcontext_t gc;
+   xcb_special_event_t *special_event;
+
+   bool first_init;
+
+   struct loader_dri3_extensions *ext;
+   struct loader_dri3_vtable *vtable;
+};
+
+void
+loader_dri3_set_swap_interval(struct loader_dri3_drawable *draw,
+                              int interval);
+
+void
+loader_dri3_drawable_fini(struct loader_dri3_drawable *draw);
+
+int
+loader_dri3_drawable_init(xcb_connection_t *conn,
+                          xcb_drawable_t drawable,
+                          __DRIscreen *dri_screen,
+                          bool is_different_gpu,
+                          const __DRIconfig *dri_config,
+                          struct loader_dri3_extensions *ext,
+                          struct loader_dri3_vtable *vtable,
+                          struct loader_dri3_drawable*);
+
+bool loader_dri3_wait_for_msc(struct loader_dri3_drawable *draw,
+                              int64_t target_msc,
+                              int64_t divisor, int64_t remainder,
+                              int64_t *ust, int64_t *msc, int64_t *sbc);
+
+int64_t
+loader_dri3_swap_buffers_msc(struct loader_dri3_drawable *draw,
+                             int64_t target_msc, int64_t divisor,
+                             int64_t remainder, unsigned flush_flags,
+                             bool force_copy);
+
+int
+loader_dri3_wait_for_sbc(struct loader_dri3_drawable *draw,
+                         int64_t target_sbc, int64_t *ust,
+                         int64_t *msc, int64_t *sbc);
+
+int loader_dri3_query_buffer_age(struct loader_dri3_drawable *draw);
+
+void
+loader_dri3_flush(struct loader_dri3_drawable *draw,
+                  unsigned flags,
+                  enum __DRI2throttleReason throttle_reason);
+
+void
+loader_dri3_copy_sub_buffer(struct loader_dri3_drawable *draw,
+                            int x, int y,
+                            int width, int height,
+                            bool flush);
+
+void
+loader_dri3_copy_drawable(struct loader_dri3_drawable *draw,
+                          xcb_drawable_t dest,
+                          xcb_drawable_t src);
+
+void
+loader_dri3_wait_x(struct loader_dri3_drawable *draw);
+
+void
+loader_dri3_wait_gl(struct loader_dri3_drawable *draw);
+
+int loader_dri3_open(xcb_connection_t *conn,
+                     xcb_window_t root,
+                     uint32_t provider);
+
+int
+loader_dri3_get_buffers(__DRIdrawable *driDrawable,
+                        unsigned int format,
+                        uint32_t *stamp,
+                        void *loaderPrivate,
+                        uint32_t buffer_mask,
+                        struct __DRIimageList *buffers);
+
+#endif