drm/nouveau: introduce a util function to wait on reg != val

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_drv.h

@@ -795,7 +795,9 @@ extern int  nouveau_ioctl_getparam(struct drm_device *, void *data,
 				   struct drm_file *);
 extern int  nouveau_ioctl_setparam(struct drm_device *, void *data,
 				   struct drm_file *);
-extern bool nouveau_wait_until(struct drm_device *, uint64_t timeout,
+extern bool nouveau_wait_eq(struct drm_device *, uint64_t timeout,
+			    uint32_t reg, uint32_t mask, uint32_t val);
+extern bool nouveau_wait_ne(struct drm_device *, uint64_t timeout,
 			    uint32_t reg, uint32_t mask, uint32_t val);
 extern bool nouveau_wait_for_idle(struct drm_device *);
 extern int  nouveau_card_init(struct drm_device *);
@@ -1434,7 +1436,9 @@ static inline void nv_wr08(struct drm_device *dev, unsigned reg, u8 val)
 }
 
 #define nv_wait(dev, reg, mask, val) \
-	nouveau_wait_until(dev, 2000000000ULL, (reg), (mask), (val))
+	nouveau_wait_eq(dev, 2000000000ULL, (reg), (mask), (val))
+#define nv_wait_ne(dev, reg, mask, val) \
+	nouveau_wait_ne(dev, 2000000000ULL, (reg), (mask), (val))
 
 /* PRAMIN access */
 static inline u32 nv_ri32(struct drm_device *dev, unsigned offset)

drivers/gpu/drm/nouveau/nouveau_hw.c

@@ -999,8 +999,8 @@ nv_load_state_ext(struct drm_device *dev, int head,
 		if (dev_priv->card_type == NV_10) {
 			/* Not waiting for vertical retrace before modifying
 			   CRE_53/CRE_54 causes lockups. */
-			nouveau_wait_until(dev, 650000000, NV_PRMCIO_INP0__COLOR, 0x8, 0x8);
-			nouveau_wait_until(dev, 650000000, NV_PRMCIO_INP0__COLOR, 0x8, 0x0);
+			nouveau_wait_eq(dev, 650000000, NV_PRMCIO_INP0__COLOR, 0x8, 0x8);
+			nouveau_wait_eq(dev, 650000000, NV_PRMCIO_INP0__COLOR, 0x8, 0x0);
 		}
 
 		wr_cio_state(dev, head, regp, NV_CIO_CRE_53);

drivers/gpu/drm/nouveau/nouveau_state.c

@@ -1126,7 +1126,8 @@ nouveau_ioctl_setparam(struct drm_device *dev, void *data,
 }
 
 /* Wait until (value(reg) & mask) == val, up until timeout has hit */
-bool nouveau_wait_until(struct drm_device *dev, uint64_t timeout,
+bool
+nouveau_wait_eq(struct drm_device *dev, uint64_t timeout,
 		uint32_t reg, uint32_t mask, uint32_t val)
 {
 	struct drm_nouveau_private *dev_priv = dev->dev_private;
@@ -1141,6 +1142,23 @@ bool nouveau_wait_until(struct drm_device *dev, uint64_t timeout,
 	return false;
 }
 
+/* Wait until (value(reg) & mask) != val, up until timeout has hit */
+bool
+nouveau_wait_ne(struct drm_device *dev, uint64_t timeout,
+		uint32_t reg, uint32_t mask, uint32_t val)
+{
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
+	struct nouveau_timer_engine *ptimer = &dev_priv->engine.timer;
+	uint64_t start = ptimer->read(dev);
+
+	do {
+		if ((nv_rd32(dev, reg) & mask) != val)
+			return true;
+	} while (ptimer->read(dev) - start < timeout);
+
+	return false;
+}
+
 /* Waits for PGRAPH to go completely idle */
 bool nouveau_wait_for_idle(struct drm_device *dev)
 {

drivers/gpu/drm/nouveau/nv04_dac.c

@@ -74,13 +74,13 @@ static int sample_load_twice(struct drm_device *dev, bool sense[2])
 		 * use a 10ms timeout (guards against crtc being inactive, in
 		 * which case blank state would never change)
 		 */
-		if (!nouveau_wait_until(dev, 10000000, NV_PRMCIO_INP0__COLOR,
+		if (!nouveau_wait_eq(dev, 10000000, NV_PRMCIO_INP0__COLOR,
 				     0x00000001, 0x00000000))
 			return -EBUSY;
-		if (!nouveau_wait_until(dev, 10000000, NV_PRMCIO_INP0__COLOR,
+		if (!nouveau_wait_eq(dev, 10000000, NV_PRMCIO_INP0__COLOR,
 				     0x00000001, 0x00000001))
 			return -EBUSY;
-		if (!nouveau_wait_until(dev, 10000000, NV_PRMCIO_INP0__COLOR,
+		if (!nouveau_wait_eq(dev, 10000000, NV_PRMCIO_INP0__COLOR,
 				     0x00000001, 0x00000000))
 			return -EBUSY;