gpu: ion: Add callbacks to enable SMI voting in ION.

This change is part of the move from PMEM to ION. ION needs an SMI
voting interface smiliar to PMEM's.

Change-Id: I18888f46198848694fb7e1e0d2671074bf51d7c9
Signed-off-by: Alex Bird <alexbird@codeaurora.org>

drivers/gpu/ion/ion_carveout_heap.c

@@ -33,6 +33,10 @@ struct ion_carveout_heap {
 	ion_phys_addr_t base;
 	unsigned long allocated_bytes;
 	unsigned long total_size;
+	void (*request_region)(void *);
+	void (*release_region)(void *);
+	atomic_t map_count;
+	void *bus_id;
 };
 
 ion_phys_addr_t ion_carveout_allocate(struct ion_heap *heap,
@@ -136,6 +140,12 @@ void ion_carveout_heap_unmap_dma(struct ion_heap *heap,
 void *ion_carveout_heap_map_kernel(struct ion_heap *heap,
 				   struct ion_buffer *buffer)
 {
+	struct ion_carveout_heap *carveout_heap =
+		container_of(heap, struct ion_carveout_heap, heap);
+
+	if (atomic_inc_return(&carveout_heap->map_count) == 1)
+		carveout_heap->request_region(carveout_heap->bus_id);
+
 	if (ION_IS_CACHED(buffer->flags))
 		return ioremap_cached(buffer->priv_phys, buffer->size);
 	else
@@ -145,14 +155,27 @@ void *ion_carveout_heap_map_kernel(struct ion_heap *heap,
 void ion_carveout_heap_unmap_kernel(struct ion_heap *heap,
 				    struct ion_buffer *buffer)
 {
+	struct ion_carveout_heap *carveout_heap =
+		container_of(heap, struct ion_carveout_heap, heap);
+
 	__arm_iounmap(buffer->vaddr);
 	buffer->vaddr = NULL;
+
+	if (atomic_dec_and_test(&carveout_heap->map_count))
+		carveout_heap->release_region(carveout_heap->bus_id);
+
 	return;
 }
 
 int ion_carveout_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer,
 			       struct vm_area_struct *vma)
 {
+	struct ion_carveout_heap *carveout_heap =
+		container_of(heap, struct ion_carveout_heap, heap);
+
+	if (atomic_inc_return(&carveout_heap->map_count) == 1)
+		carveout_heap->request_region(carveout_heap->bus_id);
+
 	if (ION_IS_CACHED(buffer->flags))
 		return remap_pfn_range(vma, vma->vm_start,
 			       __phys_to_pfn(buffer->priv_phys) + vma->vm_pgoff,
@@ -165,6 +188,16 @@ int ion_carveout_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer,
 					pgprot_noncached(vma->vm_page_prot));
 }
 
+void ion_carveout_heap_unmap_user(struct ion_heap *heap,
+				    struct ion_buffer *buffer)
+{
+	struct ion_carveout_heap *carveout_heap =
+		container_of(heap, struct ion_carveout_heap, heap);
+
+	if (atomic_dec_and_test(&carveout_heap->map_count))
+		carveout_heap->release_region(carveout_heap->bus_id);
+}
+
 int ion_carveout_cache_ops(struct ion_heap *heap, struct ion_buffer *buffer,
 			void *vaddr, unsigned int offset, unsigned int length,
 			unsigned int cmd)
@@ -213,6 +246,7 @@ static struct ion_heap_ops carveout_heap_ops = {
 	.phys = ion_carveout_heap_phys,
 	.map_user = ion_carveout_heap_map_user,
 	.map_kernel = ion_carveout_heap_map_kernel,
+	.unmap_user = ion_carveout_heap_unmap_user,
 	.unmap_kernel = ion_carveout_heap_unmap_kernel,
 	.map_dma = ion_carveout_heap_map_dma,
 	.unmap_dma = ion_carveout_heap_unmap_dma,
@@ -246,6 +280,9 @@ struct ion_heap *ion_carveout_heap_create(struct ion_platform_heap *heap_data)
 	carveout_heap->heap.type = ION_HEAP_TYPE_CARVEOUT;
 	carveout_heap->allocated_bytes = 0;
 	carveout_heap->total_size = heap_data->size;
+	carveout_heap->bus_id = heap_data->setup_region();
+	carveout_heap->request_region = heap_data->request_region;
+	carveout_heap->release_region = heap_data->release_region;
 
 	return &carveout_heap->heap;
 }

drivers/gpu/ion/ion_priv.h

@@ -74,6 +74,7 @@ struct ion_buffer {
  * @map_kernel		map memory to the kernel
  * @unmap_kernel	unmap memory to the kernel
  * @map_user		map memory to userspace
+ * @unmap_user		unmap memory to userspace
  */
 struct ion_heap_ops {
 	int (*allocate) (struct ion_heap *heap,
@@ -89,6 +90,7 @@ struct ion_heap_ops {
 	void (*unmap_kernel) (struct ion_heap *heap, struct ion_buffer *buffer);
 	int (*map_user) (struct ion_heap *mapper, struct ion_buffer *buffer,
 			 struct vm_area_struct *vma);
+	void (*unmap_user) (struct ion_heap *mapper, struct ion_buffer *buffer);
 	int (*cache_op)(struct ion_heap *heap, struct ion_buffer *buffer,
 			void *vaddr, unsigned int offset,
 			unsigned int length, unsigned int cmd);

include/linux/ion.h

@@ -98,6 +98,11 @@ struct ion_buffer;
  * @name:	used for debug purposes
  * @base:	base address of heap in physical memory if applicable
  * @size:	size of the heap in bytes if applicable
+ * @request_region: function to be called when the number of allocations goes
+ *						from 0 -> 1
+ * @release_region: function to be called when the number of allocations goes
+ *						from 1 -> 0
+ * @setup_region:   function to be called upon ion registration
  *
  * Provided by the board file.
  */
@@ -108,6 +113,9 @@ struct ion_platform_heap {
 	ion_phys_addr_t base;
 	size_t size;
 	enum ion_memory_types memory_type;
+	void (*request_region)(void *);
+	void (*release_region)(void *);
+	void *(*setup_region)(void);
 };
 
 /**