1 files changed, 24 insertions, 9 deletions
diff --git a/include/bouncebuf.h b/include/bouncebuf.h
index aa2278c..707b588 100644
--- a/include/bouncebuf.h
+++ b/include/bouncebuf.h
@@ -25,6 +25,8 @@
 #ifndef __INCLUDE_BOUNCEBUF_H__
 #define __INCLUDE_BOUNCEBUF_H__
 
+#include <linux/types.h>
+
 /*
  * GEN_BB_READ -- Data are read from the buffer eg. by DMA hardware.
  * The source buffer is copied into the bounce buffer (if unaligned, otherwise
@@ -51,23 +53,36 @@
  */
 #define GEN_BB_RW	(GEN_BB_READ | GEN_BB_WRITE)
 
+struct bounce_buffer {
+	/* Copy of data parameter passed to start() */
+	void *user_buffer;
+	/*
+	 * DMA-aligned buffer. This field is always set to the value that
+	 * should be used for DMA; either equal to .user_buffer, or to a
+	 * freshly allocated aligned buffer.
+	 */
+	void *bounce_buffer;
+	/* Copy of len parameter passed to start() */
+	size_t len;
+	/* DMA-aligned buffer length */
+	size_t len_aligned;
+	/* Copy of flags parameter passed to start() */
+	unsigned int flags;
+};
+
 /**
  * bounce_buffer_start() -- Start the bounce buffer session
+ * state:	stores state passed between bounce_buffer_{start,stop}
  * data:	pointer to buffer to be aligned
  * len:		length of the buffer
- * backup:	pointer to backup buffer (the original value is stored here if
- *              needed
  * flags:	flags describing the transaction, see above.
  */
-int bounce_buffer_start(void **data, size_t len, void **backup, uint8_t flags);
+int bounce_buffer_start(struct bounce_buffer *state, void *data,
+			size_t len, unsigned int flags);
 /**
  * bounce_buffer_stop() -- Finish the bounce buffer session
- * data:	pointer to buffer that was aligned
- * len:		length of the buffer
- * backup:	pointer to backup buffer (the original value is stored here if
- *              needed
- * flags:	flags describing the transaction, see above.
+ * state:	stores state passed between bounce_buffer_{start,stop}
  */
-int bounce_buffer_stop(void **data, size_t len, void **backup, uint8_t flags);
+int bounce_buffer_stop(struct bounce_buffer *state);
 
 #endif