Initial commit from HTC m7ul-3.4.10-jb-crc-ddcfb8c
diff --git a/include/linux/circ_buf.h b/include/linux/circ_buf.h
new file mode 100644
index 0000000..2ebacda
--- /dev/null
+++ b/include/linux/circ_buf.h
@@ -0,0 +1,25 @@
+
+#ifndef _LINUX_CIRC_BUF_H
+#define _LINUX_CIRC_BUF_H 1
+
+struct circ_buf {
+ char *buf;
+ int head;
+ int tail;
+};
+
+#define CIRC_CNT(head,tail,size) (((head) - (tail)) & ((size)-1))
+
+#define CIRC_SPACE(head,tail,size) CIRC_CNT((tail),((head)+1),(size))
+
+#define CIRC_CNT_TO_END(head,tail,size) \
+ ({int end = (size) - (tail); \
+ int n = ((head) + end) & ((size)-1); \
+ n < end ? n : end;})
+
+#define CIRC_SPACE_TO_END(head,tail,size) \
+ ({int end = (size) - 1 - (head); \
+ int n = (end + (tail)) & ((size)-1); \
+ n <= end ? n : end+1;})
+
+#endif