Use wrap counter to extend 16-bit hardware event tags to 32-bit logical

    event counters in the SAVAGE_EVENT_EMIT/WAIT ioctls. This is needed for
    reliable client-side texture heap aging. Slightly simplified DMA buffer
    aging while at it. Bumped minor version and driver date.

2 files changed, 31 insertions, 9 deletions

diff --git a/shared-core/savage_bci.c b/shared-core/savage_bci.c
index 36fb8737..3ddcccb6 100644
--- a/shared-core/savage_bci.c
+++ b/shared-core/savage_bci.c
@@ -246,6 +246,8 @@ static drm_buf_t *savage_freelist_get(drm_device_t *dev)
 	else
 		event = SAVAGE_READ(SAVAGE_STATUS_WORD1) & 0xffff;
 	wrap = dev_priv->event_wrap;
+	if (event > dev_priv->event_counter)
+	    wrap--; /* hardware hasn't passed the last wrap yet */
 
 	DRM_DEBUG("   tail=0x%04x %d\n", tail->age.event, tail->age.wrap);
 	DRM_DEBUG("   head=0x%04x %d\n", event, wrap);
@@ -623,6 +625,7 @@ int savage_bci_event_emit(DRM_IOCTL_ARGS)
 				 sizeof(event));
 
 	event.count = savage_bci_emit_event(dev_priv, event.flags);
+	event.count |= dev_priv->event_wrap << 16;
 	DRM_COPY_TO_USER_IOCTL(&((drm_savage_event_emit_t __user *)data)->count,
 			       event.count, sizeof(event.count));
 	return 0;
@@ -633,16 +636,34 @@ int savage_bci_event_wait(DRM_IOCTL_ARGS)
 	DRM_DEVICE;
 	drm_savage_private_t *dev_priv = dev->dev_private;
 	drm_savage_event_wait_t event;
+	unsigned int event_e, hw_e;
+	unsigned int event_w, hw_w;
 
 	DRM_DEBUG("\n");
 
 	DRM_COPY_FROM_USER_IOCTL(event, (drm_savage_event_wait_t __user *)data,
 				 sizeof(event));
 
-	if (event.count > 0xffff)
-		return DRM_ERR(EINVAL);
+	UPDATE_EVENT_COUNTER();
+	if (dev_priv->status_ptr)
+		hw_e = dev_priv->status_ptr[1] & 0xffff;
+	else
+		hw_e = SAVAGE_READ(SAVAGE_STATUS_WORD1) & 0xffff;
+	hw_w = dev_priv->event_wrap;
+	if (hw_e > dev_priv->event_counter)
+	    hw_w--; /* hardware hasn't passed the last wrap yet */
 
-	return dev_priv->wait_evnt(dev_priv, event.count);
+	event_e = event.count & 0xffff;
+	event_w = event.count >> 16;
+
+	/* Don't need to wait if
+	 * - event counter wrapped since the event was emitted or
+	 * - the hardware has advanced up to or over the event to wait for.
+	 */
+	if (event_w < hw_w || event_e <= hw_e )
+		return 0;
+	else
+		return dev_priv->wait_evnt(dev_priv, event_e);
 }
 
 /*
diff --git a/shared-core/savage_drv.h b/shared-core/savage_drv.h
index 54ba7e71..2b44e529 100644
--- a/shared-core/savage_drv.h
+++ b/shared-core/savage_drv.h
@@ -30,10 +30,10 @@
 
 #define DRIVER_NAME	"savage"
 #define DRIVER_DESC	"Savage3D/MX/IX, Savage4, SuperSavage, Twister, ProSavage[DDR]"
-#define DRIVER_DATE	"20050120"
+#define DRIVER_DATE	"20050222"
 
 #define DRIVER_MAJOR		2
-#define DRIVER_MINOR		2
+#define DRIVER_MINOR		3
 #define DRIVER_PATCHLEVEL	0
 /* Interface history:
  *
@@ -42,6 +42,9 @@
  * 2.1   Scissors registers managed by the DRM, 3D operations clipped by
  *       cliprects of the cmdbuf ioctl
  * 2.2   Implemented SAVAGE_CMD_DMA_IDX and SAVAGE_CMD_VB_IDX
+ * 2.3   Event counters used by BCI_EVENT_EMIT/WAIT ioctls are now 32 bits
+ *       wide and thus very long lived (unlikely to ever wrap). The size
+ *       in the struct was 32 bits before, but only 16 bits were used
  */
 
 typedef struct drm_savage_age {
@@ -489,9 +492,7 @@ extern void savage_emit_clip_rect_s4(drm_savage_private_t *dev_priv,
 	(age)->wrap = w;		\
 } while(0)
 
-#define TEST_AGE( age, e, w )						\
-	( (age)->wrap+1 < (w) ||					\
-	  ( (age)->wrap+1 == (w) && (e) <= dev_priv->event_counter ) ||	\
-	  (age)->event <= (e) )
+#define TEST_AGE( age, e, w )				\
+	( (age)->wrap < (w) || (age)->event <= (e) )
 
 #endif /* __SAVAGE_DRV_H__ */