kfifo: use void * pointers for user buffers

The pointers to user buffers are currently unsigned char *, which requires
a lot of casting in the caller for any non-char typed buffers.  Use void *
instead.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Andy Walls <awalls@radix.net>
Cc: Vikram Dhillon <dhillonv10@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/kfifo.h

@@ -104,15 +104,15 @@ union { \
 
 #undef __kfifo_initializer
 
-extern void kfifo_init(struct kfifo *fifo, unsigned char *buffer,
+extern void kfifo_init(struct kfifo *fifo, void *buffer,
 			unsigned int size);
 extern __must_check int kfifo_alloc(struct kfifo *fifo, unsigned int size,
 			gfp_t gfp_mask);
 extern void kfifo_free(struct kfifo *fifo);
 extern unsigned int kfifo_in(struct kfifo *fifo,
-				const unsigned char *from, unsigned int len);
+				const void *from, unsigned int len);
 extern __must_check unsigned int kfifo_out(struct kfifo *fifo,
-				unsigned char *to, unsigned int len);
+				void *to, unsigned int len);
 
 /**
  * kfifo_reset - removes the entire FIFO contents
@@ -194,7 +194,7 @@ static inline __must_check unsigned int kfifo_avail(struct kfifo *fifo)
  * bytes copied.
  */
 static inline unsigned int kfifo_in_locked(struct kfifo *fifo,
-		const unsigned char *from, unsigned int n, spinlock_t *lock)
+		const void *from, unsigned int n, spinlock_t *lock)
 {
 	unsigned long flags;
 	unsigned int ret;
@@ -219,7 +219,7 @@ static inline unsigned int kfifo_in_locked(struct kfifo *fifo,
  * @to buffer and returns the number of copied bytes.
  */
 static inline __must_check unsigned int kfifo_out_locked(struct kfifo *fifo,
-	unsigned char *to, unsigned int n, spinlock_t *lock)
+	void *to, unsigned int n, spinlock_t *lock)
 {
 	unsigned long flags;
 	unsigned int ret;

kernel/kfifo.c

@@ -28,7 +28,7 @@
 #include <linux/log2.h>
 #include <linux/uaccess.h>
 
-static void _kfifo_init(struct kfifo *fifo, unsigned char *buffer,
+static void _kfifo_init(struct kfifo *fifo, void *buffer,
 		unsigned int size)
 {
 	fifo->buffer = buffer;
@@ -44,7 +44,7 @@ static void _kfifo_init(struct kfifo *fifo, unsigned char *buffer,
  * @size: the size of the internal buffer, this have to be a power of 2.
  *
  */
-void kfifo_init(struct kfifo *fifo, unsigned char *buffer, unsigned int size)
+void kfifo_init(struct kfifo *fifo, void *buffer, unsigned int size)
 {
 	/* size must be a power of 2 */
 	BUG_ON(!is_power_of_2(size));
@@ -235,7 +235,7 @@ EXPORT_SYMBOL(__kfifo_in_n);
  * Note that with only one concurrent reader and one concurrent
  * writer, you don't need extra locking to use these functions.
  */
-unsigned int kfifo_in(struct kfifo *fifo, const unsigned char *from,
+unsigned int kfifo_in(struct kfifo *fifo, const void *from,
 				unsigned int len)
 {
 	len = min(kfifo_avail(fifo), len);
@@ -277,7 +277,7 @@ EXPORT_SYMBOL(__kfifo_out_n);
  * Note that with only one concurrent reader and one concurrent
  * writer, you don't need extra locking to use these functions.
  */
-unsigned int kfifo_out(struct kfifo *fifo, unsigned char *to, unsigned int len)
+unsigned int kfifo_out(struct kfifo *fifo, void *to, unsigned int len)
 {
 	len = min(kfifo_len(fifo), len);