staging: android: persistent_ram: Introduce persistent_ram_free()

A corresponding function to persistent_ram_new().
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/persistent_ram.c

@@ -364,6 +364,9 @@ static void *persistent_ram_iomap(phys_addr_t start, size_t size)
 static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size,
 		struct persistent_ram_zone *prz)
 {
+	prz->paddr = start;
+	prz->size = size;
+
 	if (pfn_valid(start >> PAGE_SHIFT))
 		prz->vaddr = persistent_ram_vmap(start, size);
 	else
@@ -437,6 +440,18 @@ static int __init persistent_ram_post_init(struct persistent_ram_zone *prz, bool
 	return 0;
 }
 
+void persistent_ram_free(struct persistent_ram_zone *prz)
+{
+	if (pfn_valid(prz->paddr >> PAGE_SHIFT)) {
+		vunmap(prz->vaddr);
+	} else {
+		iounmap(prz->vaddr);
+		release_mem_region(prz->paddr, prz->size);
+	}
+	persistent_ram_free_old(prz);
+	kfree(prz);
+}
+
 struct persistent_ram_zone * __init persistent_ram_new(phys_addr_t start,
 						       size_t size,
 						       bool ecc)

drivers/staging/android/persistent_ram.h

@@ -39,6 +39,8 @@ struct persistent_ram {
 };
 
 struct persistent_ram_zone {
+	phys_addr_t paddr;
+	size_t size;
 	void *vaddr;
 	struct persistent_ram_buffer *buffer;
 	size_t buffer_size;
@@ -66,6 +68,7 @@ int persistent_ram_early_init(struct persistent_ram *ram);
 struct persistent_ram_zone * __init persistent_ram_new(phys_addr_t start,
 						       size_t size,
 						       bool ecc);
+void persistent_ram_free(struct persistent_ram_zone *prz);
 struct persistent_ram_zone *persistent_ram_init_ringbuffer(struct device *dev,
 		bool ecc);