[PATCH] nvc0: Add and enable vblank support

[Maarten Lankhorst <maarten.lankhorst-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>]

Based on the original patch by Christoph Bumiller, but since
it depends on kernel support patched I cannot push it yet.

The changes are that I enable vblank by default, and offset
takes OFFSET_HIGH/LOW instead of something relative to notifier_bo.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>

---
diff --git a/man/nouveau.man b/man/nouveau.man
index 7c72907..8765569 100644
--- a/man/nouveau.man
+++ b/man/nouveau.man
@@ -79,7 +79,7 @@ Enable or disable wfb, only affects nv50+. Useful for some legacy configurations
 .BI "Option \*qGLXVBlank\*q \*q" boolean \*q
 Synchronize GLX clients to VBlank. Useful where tearing is a problem,
 harmful if the GPU isn't fast enough to keep up with the monitor
-refresh rate. Default: off.
+refresh rate. Default: on.
 .TP
 .BI "Option \*qZaphodHeads\*q \*q" string \*q
 Specify the randr output(s) to use with zaphod mode for a particular driver
diff --git a/src/nouveau_dri2.c b/src/nouveau_dri2.c
index 0b3cc38..62333b1 100644
--- a/src/nouveau_dri2.c
+++ b/src/nouveau_dri2.c
@@ -316,6 +316,9 @@ nouveau_dri2_finish_swap(DrawablePtr draw, unsigned int frame,
 					   NOUVEAU_BO_VRAM | NOUVEAU_BO_RD
 				     }, 1);
 
+		if (pNv->Architecture >= NV_ARCH_C0)
+			NVC0SyncToVBlank(dst_pix, REGION_EXTENTS(0, &reg));
+		else
 		if (pNv->Architecture >= NV_ARCH_50)
 			NV50SyncToVBlank(dst_pix, REGION_EXTENTS(0, &reg));
 		else
diff --git a/src/nv_dma.c b/src/nv_dma.c
index d2a6d00..47c7e12 100644
--- a/src/nv_dma.c
+++ b/src/nv_dma.c
@@ -63,6 +63,18 @@ NVInitDma(ScrnInfoPtr pScrn)
 	xf86DrvMsg(pScrn->scrnIndex, X_INFO,
 		   "Opened GPU channel %d\n", fifo->channel);
 
+	if (pNv->Architecture >= NV_ARCH_C0) {
+		struct nvc0_fifo *data = (struct nvc0_fifo *)fifo;
+		ret = nouveau_bo_wrap(pNv->dev, data->notify,
+		                      &pNv->notifier_bo);
+		if (ret) {
+			xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
+			           "Failed to obtain notifier bo: %d\n", ret);
+			NVTakedownDma(pScrn);
+			return FALSE;
+		}
+	}
+
 	ret = nouveau_pushbuf_new(pNv->client, pNv->channel, 4, 32 * 1024,
 				  true, &pNv->pushbuf);
 	if (ret) {
diff --git a/src/nv_driver.c b/src/nv_driver.c
index beef789..dd6f005 100644
--- a/src/nv_driver.c
+++ b/src/nv_driver.c
@@ -815,6 +815,7 @@ NVPreInit(ScrnInfoPtr pScrn, int flags)
 
 	if (!pNv->NoAccel && pNv->dev->chipset >= 0x11) {
 		from = X_DEFAULT;
+		pNv->glx_vblank = TRUE;
 		if (xf86GetOptValBool(pNv->Options, OPTION_GLX_VBLANK,
 				      &pNv->glx_vblank))
 			from = X_CONFIG;
diff --git a/src/nv_proto.h b/src/nv_proto.h
index b546ebd..bcf927d 100644
--- a/src/nv_proto.h
+++ b/src/nv_proto.h
@@ -149,6 +149,7 @@ Bool NVAccelInit2D_NV50(ScrnInfoPtr pScrn);
 Bool NVAccelInitNV50TCL(ScrnInfoPtr pScrn);
 
 /* in nvc0_accel.c */
+void NVC0SyncToVBlank(PixmapPtr ppix, BoxPtr box);
 Bool NVAccelInitM2MF_NVC0(ScrnInfoPtr pScrn);
 Bool NVAccelInitCopy_NVC0(ScrnInfoPtr pScrn);
 Bool NVAccelInitP2MF_NVE0(ScrnInfoPtr pScrn);
diff --git a/src/nv_type.h b/src/nv_type.h
index e1ea494..272e34f 100644
--- a/src/nv_type.h
+++ b/src/nv_type.h
@@ -102,6 +102,7 @@ typedef struct _NVRec {
 	struct nouveau_object *Nv2D;
 	struct nouveau_object *Nv3D;
 	struct nouveau_object *NvSW;
+	struct nouveau_bo *notifier_bo;
 	struct nouveau_bo *scratch;
 
 	Bool ce_enabled;
diff --git a/src/nvc0_accel.c b/src/nvc0_accel.c
index c5da0cd..4cae0d2 100644
--- a/src/nvc0_accel.c
+++ b/src/nvc0_accel.c
@@ -25,6 +25,36 @@
 #include "nvc0_shader.h"
 #include "nve0_shader.h"
 
+void
+NVC0SyncToVBlank(PixmapPtr ppix, BoxPtr box)
+{
+	ScrnInfoPtr pScrn = xf86Screens[ppix->drawable.pScreen->myNum];
+	NVPtr pNv = NVPTR(pScrn);
+	struct nouveau_pushbuf *push = pNv->pushbuf;
+	int crtcs;
+
+	if (!nouveau_exa_pixmap_is_onscreen(ppix))
+		return;
+
+	crtcs = nv_window_belongs_to_crtc(pScrn, box->x1, box->y1,
+	                                  box->x2 - box->x1,
+	                                  box->y2 - box->y1);
+	if (!crtcs)
+		return;
+
+	BEGIN_NVC0(push, SUBC_NVSW(NV84_SUBCHAN_SEMAPHORE_ADDRESS_HIGH), 4);
+	PUSH_DATA (push, pNv->notifier_bo->offset >> 32);
+	PUSH_DATA (push, pNv->notifier_bo->offset);
+	PUSH_DATA (push, 0x22222222);
+	PUSH_DATA (push, NV84_SUBCHAN_SEMAPHORE_TRIGGER_WRITE_LONG);
+	BEGIN_NVC0(push, SUBC_NVSW(0x0208), 2);
+	PUSH_DATA (push, 0x11111111);
+	PUSH_DATA (push, ffs(crtcs) - 1);
+	BEGIN_NVC0(push, SUBC_NVSW(NV84_SUBCHAN_SEMAPHORE_SEQUENCE), 2);
+	PUSH_DATA (push, 0x11111111);
+	PUSH_DATA (push, NV84_SUBCHAN_SEMAPHORE_TRIGGER_ACQUIRE_EQUAL);
+}
+
 Bool
 NVAccelInitM2MF_NVC0(ScrnInfoPtr pScrn)
 {
@@ -153,12 +183,27 @@ NVAccelInit3D_NVC0(ScrnInfoPtr pScrn)
 	if (ret)
 		return FALSE;
 
+	ret = nouveau_object_new(pNv->channel, 0x906e, 0x906e,
+				 NULL, 0, &pNv->NvSW);
+
 	if (nouveau_pushbuf_space(push, 512, 0, 0) ||
 	    nouveau_pushbuf_refn (push, &(struct nouveau_pushbuf_refn) {
 					pNv->scratch, NOUVEAU_BO_VRAM |
 					NOUVEAU_BO_WR }, 1))
 		return FALSE;
 
+	if (!ret) {
+		BEGIN_NVC0(push, NV01_SUBC(NVSW, OBJECT), 1);
+		PUSH_DATA (push, pNv->NvSW->handle);
+		BEGIN_NVC0(push, SUBC_NVSW(0x0200), 2); /* VBLSEM_OFFSET */
+		PUSH_DATA (push, pNv->notifier_bo->offset >> 32);
+		PUSH_DATA (push, pNv->notifier_bo->offset);
+	} else if (pNv->glx_vblank) {
+		xf86DrvMsg(pScrn->scrnIndex, X_WARNING,
+			   "No kernel support for GLX sync to VBlank.\n");
+		pNv->glx_vblank = false;
+	}
+
 	BEGIN_NVC0(push, NV01_SUBC(3D, OBJECT), 1);
 	PUSH_DATA (push, pNv->Nv3D->handle);
 	BEGIN_NVC0(push, NVC0_3D(COND_MODE), 1);
diff --git a/src/nvc0_xv.c b/src/nvc0_xv.c
index 3b6d01f..86b7948 100644
--- a/src/nvc0_xv.c
+++ b/src/nvc0_xv.c
@@ -221,9 +221,8 @@ nvc0_xv_image_put(ScrnInfoPtr pScrn,
 	PUSH_DATAf(push, 1.0 / width);
 	PUSH_DATAf(push, 1.0 / height);
 
-	if (0 && pPriv->SyncToVBlank) {
-		NV50SyncToVBlank(ppix, dstBox);
-	}
+	if (pPriv->SyncToVBlank)
+		NVC0SyncToVBlank(ppix, dstBox);
 
 	/* These are fixed point values in the 16.16 format. */
 	X1 = (float)(x1>>16)+(float)(x1&0xFFFF)/(float)0x10000;