uxa: do copy fb at startup.

Copy the current framebuffer for smooth wayland->gdm handoff.

This has been hanging around in Fedora for too long now, and we've
dropped the feature a few times, and yes I know the Simpsons did it^W^W^W
SNA does it.

I've updated the code to have some of the better fixes from nouveau.

I've no idea who wrote this code either, krh or ajax. [ickle: The
earliest version I've found had krh's fingerprints on it, though it may
still have been a joint effort.]

Signed-off-by: Dave Airlie <airlied@redhat.com>
[ickle: improve error handling, only copy the fb during initial takeover]

3 files changed, 135 insertions, 1 deletions

diff --git a/src/intel.h b/src/intel.h
index 20d82826..caf07bb0 100644
--- a/src/intel.h
+++ b/src/intel.h
@@ -368,6 +368,7 @@ extern void intel_mode_fini(intel_screen_private *intel);
 extern int intel_get_pipe_from_crtc_id(drm_intel_bufmgr *bufmgr, xf86CrtcPtr crtc);
 extern int intel_crtc_id(xf86CrtcPtr crtc);
 extern int intel_output_dpms_status(xf86OutputPtr output);
+extern void intel_copy_fb(ScrnInfoPtr scrn);
 
 enum DRI2FrameEventType {
 	DRI2_SWAP,
diff --git a/src/intel_display.c b/src/intel_display.c
index 6f3f7e64..8de63449 100644
--- a/src/intel_display.c
+++ b/src/intel_display.c
@@ -35,6 +35,7 @@
 #include <unistd.h>
 #include <errno.h>
 #include <poll.h>
+#include <sys/ioctl.h>
 
 #include "xorgVersion.h"
 
@@ -45,6 +46,8 @@
 #include "X11/Xatom.h"
 #include "X11/extensions/dpmsconst.h"
 #include "xf86DDC.h"
+#include "fb.h"
+#include "uxa.h"
 
 #include "intel_glamor.h"
 
@@ -1748,3 +1751,129 @@ Bool intel_crtc_on(xf86CrtcPtr crtc)
 
 	return ret;
 }
+
+static PixmapPtr
+intel_create_pixmap_for_bo(ScreenPtr pScreen, dri_bo *bo,
+			   int width, int height,
+			   int depth, int bpp,
+			   int pitch)
+{
+	PixmapPtr pixmap;
+
+	pixmap = pScreen->CreatePixmap(pScreen, 0, 0, depth, 0);
+	if (pixmap == NullPixmap)
+		return pixmap;
+
+	if (!pScreen->ModifyPixmapHeader(pixmap,
+					 width, height,
+					 depth, bpp,
+					 pitch, NULL)) {
+		pScreen->DestroyPixmap(pixmap);
+		return NullPixmap;
+	}
+
+	intel_set_pixmap_bo(pixmap, bo);
+	return pixmap;
+}
+
+static PixmapPtr
+intel_create_pixmap_for_fbcon(ScrnInfoPtr scrn, int fbcon_id)
+{
+	ScreenPtr pScreen = xf86ScrnToScreen(scrn);
+	intel_screen_private *intel = intel_get_screen_private(scrn);
+	struct intel_mode *mode = intel->modes;
+	int fd = mode->fd;
+	drmModeFBPtr fbcon;
+	struct drm_gem_flink flink;
+	drm_intel_bo *bo;
+	PixmapPtr pixmap = NullPixmap;
+
+	fbcon = drmModeGetFB(fd, fbcon_id);
+	if (fbcon == NULL)
+		return NULL;
+
+	if (fbcon->depth != scrn->depth ||
+	    fbcon->width != scrn->virtualX ||
+	    fbcon->height != scrn->virtualY)
+		goto out_free_fb;
+
+	flink.handle = fbcon->handle;
+	if (ioctl(fd, DRM_IOCTL_GEM_FLINK, &flink) < 0) {
+		xf86DrvMsg(scrn->scrnIndex, X_ERROR,
+			   "Couldn't flink fbcon handle\n");
+		goto out_free_fb;
+	}
+
+	bo = drm_intel_bo_gem_create_from_name(intel->bufmgr,
+					       "fbcon", flink.name);
+	if (bo == NULL) {
+		xf86DrvMsg(scrn->scrnIndex, X_ERROR,
+			   "Couldn't allocate bo for fbcon handle\n");
+		goto out_free_fb;
+	}
+
+	pixmap = intel_create_pixmap_for_bo(pScreen, bo,
+					    fbcon->width, fbcon->height,
+					    fbcon->depth, fbcon->bpp,
+					    fbcon->pitch);
+	if (pixmap == NullPixmap)
+		xf86DrvMsg(scrn->scrnIndex, X_ERROR,
+			   "Couldn't allocate pixmap fbcon contents\n");
+	drm_intel_bo_unreference(bo);
+out_free_fb:
+	drmModeFreeFB(fbcon);
+
+	return pixmap;
+}
+
+void intel_copy_fb(ScrnInfoPtr scrn)
+{
+	xf86CrtcConfigPtr xf86_config = XF86_CRTC_CONFIG_PTR(scrn);
+	ScreenPtr pScreen = xf86ScrnToScreen(scrn);
+	intel_screen_private *intel = intel_get_screen_private(scrn);
+	PixmapPtr src, dst;
+	unsigned int pitch = scrn->displayWidth * intel->cpp;
+	struct intel_crtc *intel_crtc;
+	int i, fbcon_id;
+
+	if (intel->force_fallback)
+		return;
+
+	fbcon_id = 0;
+	for (i = 0; i < xf86_config->num_crtc; i++) {
+		intel_crtc = xf86_config->crtc[i]->driver_private;
+		if (intel_crtc->mode_crtc->buffer_id)
+			fbcon_id = intel_crtc->mode_crtc->buffer_id;
+	}
+	if (!fbcon_id)
+		return;
+
+	src = intel_create_pixmap_for_fbcon(scrn, fbcon_id);
+	if (src == NULL)
+		return;
+
+	/* We dont have a screen Pixmap yet */
+	dst = intel_create_pixmap_for_bo(pScreen, intel->front_buffer,
+					 scrn->virtualX, scrn->virtualY,
+					 scrn->depth, scrn->bitsPerPixel,
+					 pitch);
+	if (dst == NullPixmap)
+		goto cleanup_src;
+
+	if (!intel->uxa_driver->prepare_copy(src, dst,
+					     -1, -1,
+					     GXcopy, FB_ALLONES))
+		goto cleanup_dst;
+
+	intel->uxa_driver->copy(dst,
+				0, 0,
+				0, 0,
+				scrn->virtualX, scrn->virtualY);
+	intel->uxa_driver->done_copy(dst);
+	pScreen->canDoBGNoneRoot = TRUE;
+
+cleanup_dst:
+	(*pScreen->DestroyPixmap)(dst);
+cleanup_src:
+	(*pScreen->DestroyPixmap)(src);
+}
diff --git a/src/intel_driver.c b/src/intel_driver.c
index 67cec488..8962a112 100644
--- a/src/intel_driver.c
+++ b/src/intel_driver.c
@@ -167,7 +167,11 @@ static Bool i830CreateScreenResources(ScreenPtr screen)
 	if (!(*screen->CreateScreenResources) (screen))
 		return FALSE;
 
-	return intel_uxa_create_screen_resources(screen);
+	if (!intel_uxa_create_screen_resources(screen))
+		return FALSE;
+
+	intel_copy_fb(scrn);
+	return TRUE;
 }
 
 static void PreInitCleanup(ScrnInfoPtr scrn)