ion: remove ion_heap_alloc_pages

Now that ion_vm_fault doesn't need a struct page with a nonzero
refcount, there is no need allocate heap memory for cached pages using
split_page.  Remove the ion_heap_alloc_pages and ion_heap_free_pages
helpers in favor of direct calls to alloc_pages and __free_pages,
and remove the special handling in the system heap.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/ion/ion_heap.c

@@ -148,33 +148,6 @@ end:
 	return ret;
 }
 
-struct page *ion_heap_alloc_pages(struct ion_buffer *buffer, gfp_t gfp_flags,
-				  unsigned int order)
-{
-	struct page *page = alloc_pages(gfp_flags, order);
-
-	if (!page)
-		return page;
-
-	if (ion_buffer_fault_user_mappings(buffer))
-		split_page(page, order);
-
-	return page;
-}
-
-void ion_heap_free_pages(struct ion_buffer *buffer, struct page *page,
-			 unsigned int order)
-{
-	int i;
-
-	if (!ion_buffer_fault_user_mappings(buffer)) {
-		__free_pages(page, order);
-		return;
-	}
-	for (i = 0; i < (1 << order); i++)
-		__free_page(page + i);
-}
-
 void ion_heap_freelist_add(struct ion_heap *heap, struct ion_buffer * buffer)
 {
 	rt_mutex_lock(&heap->lock);

drivers/staging/android/ion/ion_priv.h

@@ -216,19 +216,6 @@ int ion_heap_map_user(struct ion_heap *, struct ion_buffer *,
 			struct vm_area_struct *);
 int ion_heap_buffer_zero(struct ion_buffer *buffer);
 
-/**
- * ion_heap_alloc_pages - allocate pages from alloc_pages
- * @buffer:		the buffer to allocate for, used to extract the flags
- * @gfp_flags:		the gfp_t for the allocation
- * @order:		the order of the allocatoin
- *
- * This funciton allocations from alloc pages and also does any other
- * necessary operations based on the buffer->flags.  For buffers which
- * will be faulted in the pages are split using split_page
- */
-struct page *ion_heap_alloc_pages(struct ion_buffer *buffer, gfp_t gfp_flags,
-				  unsigned int order);
-
 /**
  * ion_heap_init_deferred_free -- initialize deferred free functionality
  * @heap:		the heap

drivers/staging/android/ion/ion_system_heap.c

@@ -74,7 +74,7 @@ static struct page *alloc_buffer_page(struct ion_system_heap *heap,
 
 		if (order > 4)
 			gfp_flags = high_order_gfp_flags;
-		page = ion_heap_alloc_pages(buffer, gfp_flags, order);
+		page = alloc_pages(gfp_flags, order);
 		if (!page)
 			return 0;
 		ion_pages_sync_for_device(NULL, page, PAGE_SIZE << order,
@@ -91,15 +91,10 @@ static void free_buffer_page(struct ion_system_heap *heap,
 			     unsigned int order)
 {
 	bool cached = ion_buffer_cached(buffer);
-	bool split_pages = ion_buffer_fault_user_mappings(buffer);
-	int i;
 
 	if (!cached) {
 		struct ion_page_pool *pool = heap->pools[order_to_index(order)];
 		ion_page_pool_free(pool, page);
-	} else if (split_pages) {
-		for (i = 0; i < (1 << order); i++)
-			__free_page(page + i);
 	} else {
 		__free_pages(page, order);
 	}