gma500: finish off the fault handler

GEM wants to mmap the object through the GTT (which avoids aliasing) so we
need to put the object into the GTT before we provide the fault mapping for
it.

While we are at it update the pin interface so that it digs dev out of the
GEM object itself. This provides a rather cleaner API and call environment.
Fix th refcount/on-off confusion in the pin API.

At this point we get a bit further with modetest but if we write to the
new GEM mapping we hang solid and as yet I don't know why.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 49 insertions, 10 deletions

diff --git a/drivers/staging/gma500/psb_gtt.c b/drivers/staging/gma500/psb_gtt.c
index dc0a4b7850d2..74c5a6569d08 100644
--- a/drivers/staging/gma500/psb_gtt.c
+++ b/drivers/staging/gma500/psb_gtt.c
@@ -78,6 +78,7 @@ u32 *psb_gtt_entry(struct drm_device *dev, struct gtt_range *r)
  */
 static int psb_gtt_insert(struct drm_device *dev, struct gtt_range *r)
 {
+        struct drm_psb_private *dev_priv = dev->dev_private;
 	u32 *gtt_slot, pte;
 	int numpages = (r->resource.end + 1 - r->resource.start) >> PAGE_SHIFT;
 	struct page **pages;
@@ -93,6 +94,9 @@ static int psb_gtt_insert(struct drm_device *dev, struct gtt_range *r)
 	gtt_slot = psb_gtt_entry(dev, r);
 	pages = r->pages;
 
+	/* Make sure we have no alias present */
+	wbinvd();
+
 	/* Write our page entries into the GART itself */
 	for (i = 0; i < numpages; i++) {
 		pte = psb_gtt_mask_pte(page_to_pfn(*pages++), 0/*type*/);
@@ -101,8 +105,6 @@ static int psb_gtt_insert(struct drm_device *dev, struct gtt_range *r)
 	/* Make sure all the entries are set before we return */
 	ioread32(gtt_slot - 1);
 	
-	r->in_gart = 1;
-
 	return 0;
 }
 
@@ -130,8 +132,6 @@ static void psb_gtt_remove(struct drm_device *dev, struct gtt_range *r)
 	for (i = 0; i < numpages; i++)
 		iowrite32(pte, gtt_slot++);
 	ioread32(gtt_slot - 1);
-	
-	r->in_gart = 0;
 }
 
 /**
@@ -140,6 +140,8 @@ static void psb_gtt_remove(struct drm_device *dev, struct gtt_range *r)
  *
  *	Pin and build an in kernel list of the pages that back our GEM object.
  *	While we hold this the pages cannot be swapped out
+ *
+ *	FIXME: Do we need to cache flush when we update the GTT
  */
 static int psb_gtt_attach_pages(struct gtt_range *gt)
 {
@@ -183,6 +185,8 @@ err:
  *	Undo the effect of psb_gtt_attach_pages. At this point the pages
  *	must have been removed from the GART as they could now be paged out
  *	and move bus address.
+ *
+ *	FIXME: Do we need to cache flush when we update the GTT
  */
 static void psb_gtt_detach_pages(struct gtt_range *gt)
 {
@@ -199,13 +203,20 @@ static void psb_gtt_detach_pages(struct gtt_range *gt)
 	gt->pages = NULL;
 }
 
-/*
- *	Manage pinning of resources into the GART
+/**
+ *	psb_gtt_pin		-	pin pages into the GTT
+ *	@gt: range to pin
+ *
+ *	Pin a set of pages into the GTT. The pins are refcounted so that
+ *	multiple pins need multiple unpins to undo.
+ *
+ *	Non GEM backed objects treat this as a no-op as they are always GTT
+ *	backed objects.
  */
-
-int psb_gtt_pin(struct drm_device *dev, struct gtt_range *gt)
+int psb_gtt_pin(struct gtt_range *gt)
 {
 	int ret;
+	struct drm_device *dev = gt->gem.dev;
 	struct drm_psb_private *dev_priv = dev->dev_private;
 
 	mutex_lock(&dev_priv->gtt_mutex);
@@ -226,8 +237,20 @@ out:
 	return ret;
 }
 
-void psb_gtt_unpin(struct drm_device *dev, struct gtt_range *gt)
+/**
+ *	psb_gtt_unpin		-	Drop a GTT pin requirement
+ *	@gt: range to pin
+ *
+ *	Undoes the effect of psb_gtt_pin. On the last drop the GEM object
+ *	will be removed from the GTT which will also drop the page references
+ *	and allow the VM to clean up or page stuff.
+ *
+ *	Non GEM backed objects treat this as a no-op as they are always GTT
+ *	backed objects.
+ */
+void psb_gtt_unpin(struct gtt_range *gt)
 {
+	struct drm_device *dev = gt->gem.dev;
 	struct drm_psb_private *dev_priv = dev->dev_private;
 
 	mutex_lock(&dev_priv->gtt_mutex);
@@ -239,7 +262,6 @@ void psb_gtt_unpin(struct drm_device *dev, struct gtt_range *gt)
 		psb_gtt_remove(dev, gt);
 		psb_gtt_detach_pages(gt);
 	}
-
 	mutex_unlock(&dev_priv->gtt_mutex);
 }
 	
@@ -286,6 +308,8 @@ struct gtt_range *psb_gtt_alloc_range(struct drm_device *dev, int len,
         gt->resource.name = name;
         gt->stolen = backed;
         gt->in_gart = backed;
+        /* Ensure this is set for non GEM objects */
+        gt->gem.dev = dev;
 	kref_init(&gt->kref);
 
 	ret = allocate_resource(dev_priv->gtt_mem, &gt->resource,
@@ -298,9 +322,24 @@ struct gtt_range *psb_gtt_alloc_range(struct drm_device *dev, int len,
 	return NULL;
 }
 
+/**
+ *	psb_gtt_destroy		-	final free up of a gtt
+ *	@kref: the kref of the gtt
+ *
+ *	Called from the kernel kref put when the final reference to our
+ *	GTT object is dropped. At that point we can free up the resources.
+ *
+ *	For now we handle mmap clean up here to work around limits in GEM
+ */
 static void psb_gtt_destroy(struct kref *kref)
 {
 	struct gtt_range *gt = container_of(kref, struct gtt_range, kref);
+
+	/* Undo the mmap pin if we are destroying the object */
+	if (gt->mmapping) {
+		psb_gtt_unpin(gt);
+		gt->mmapping = 0;
+	}
 	WARN_ON(gt->in_gart && !gt->stolen);
 	release_resource(&gt->resource);
 	kfree(gt);