3 files changed, 30 insertions, 2 deletions
diff --git a/sys/dev/pci/drm/i915_dma.c b/sys/dev/pci/drm/i915_dma.c
index 79959d9e264..e3da1437e7a 100644
--- a/sys/dev/pci/drm/i915_dma.c
+++ b/sys/dev/pci/drm/i915_dma.c
@@ -86,6 +86,8 @@ i915_init_phys_hws(drm_i915_private_t *dev_priv, bus_dma_tag_t dmat)
 
 	memset(dev_priv->hw_status_page, 0, PAGE_SIZE);
 
+	bus_dmamap_sync(dmat, dev_priv->hws_dmamem->map, 0, PAGE_SIZE,
+	    BUS_DMASYNC_PREREAD);
 	I915_WRITE(HWS_PGA, dev_priv->hws_dmamem->map->dm_segs[0].ds_addr);
 	DRM_DEBUG("Enabled hardware status page\n");
 	return (0);
@@ -221,9 +223,12 @@ static int i915_dma_resume(struct drm_device * dev)
 
 	if (dev_priv->status_gfx_addr != 0)
 		I915_WRITE(HWS_PGA, dev_priv->status_gfx_addr);
-	else
+	else {
+		bus_dmamap_sync(dev->dmat, dev_priv->hws_dmamem->map, 0,
+		    PAGE_SIZE, BUS_DMASYNC_PREREAD);
 		I915_WRITE(HWS_PGA,
 		    dev_priv->hws_dmamem->map->dm_segs[0].ds_addr);
+	}
 	DRM_DEBUG("Enabled hardware status page\n");
 
 	return 0;
diff --git a/sys/dev/pci/drm/i915_drv.c b/sys/dev/pci/drm/i915_drv.c
index 3a63b4d29e9..96ec2ce995a 100644
--- a/sys/dev/pci/drm/i915_drv.c
+++ b/sys/dev/pci/drm/i915_drv.c
@@ -244,3 +244,25 @@ inteldrm_ioctl(struct drm_device *dev, u_long cmd, caddr_t data,
 	}
 	return (EINVAL);
 }
+
+u_int32_t
+inteldrm_read_hws(struct drm_i915_private *dev_priv, int reg)
+{
+	struct drm_device	*dev = (struct drm_device *)dev_priv->drmdev;
+	u_int32_t		 val;
+
+	/*
+	 * When we eventually go GEM only we'll always have a dmamap, so this
+	 * madness won't be for long.
+	 */
+	if (dev_priv->hws_dmamem)
+		bus_dmamap_sync(dev->dmat, dev_priv->hws_dmamem->map, 0,
+		    PAGE_SIZE, BUS_DMASYNC_POSTREAD);
+	
+	val = ((volatile u_int32_t *)(dev_priv->hw_status_page))[reg];
+
+	if (dev_priv->hws_dmamem)
+		bus_dmamap_sync(dev->dmat, dev_priv->hws_dmamem->map, 0,
+		    PAGE_SIZE, BUS_DMASYNC_PREREAD);
+	return (val);
+}
diff --git a/sys/dev/pci/drm/i915_drv.h b/sys/dev/pci/drm/i915_drv.h
index 382521738a7..e3e4cdfce81 100644
--- a/sys/dev/pci/drm/i915_drv.h
+++ b/sys/dev/pci/drm/i915_drv.h
@@ -214,6 +214,7 @@ typedef struct drm_i915_private {
 #define CHIP_HWS	0x8000
 
 				/* i915_dma.c */
+u_int32_t	inteldrm_read_hws(struct drm_i915_private *, int);
 extern void i915_kernel_lost_context(struct drm_device * dev);
 extern void i915_driver_lastclose(struct drm_device * dev);
 extern void i915_driver_close(struct drm_device *dev,
@@ -446,7 +447,7 @@ extern int i915_wait_ring(struct drm_device * dev, int n, const char *caller);
  *
  * The area from dword 0x20 to 0x3ff is available for driver usage.
  */
-#define READ_HWSP(dev_priv, reg)  (((volatile u32*)(dev_priv->hw_status_page))[reg])
+#define READ_HWSP(dev_priv, reg)  inteldrm_read_hws(dev_priv, reg)
 #define READ_BREADCRUMB(dev_priv) READ_HWSP(dev_priv, I915_BREADCRUMB_INDEX)
 #define I915_GEM_HWS_INDEX		0x20
 #define	I915_BREADCRUMB_INDEX		0x21