Merge branch 'linus' into cont_syslog

[safe/jmp/linux-2.6] / include / linux / kfifo.h

diff --git a/include/linux/kfifo.h b/include/linux/kfifo.h
index 7ad6d32..9fad052 100644 (file)
--- a/include/linux/kfifo.h
+++ b/include/linux/kfifo.h
@@ -67,7 +67,7 @@ struct kfifo {
 /**
  * DECLARE_KFIFO - macro to declare a kfifo and the associated buffer
  * @name: name of the declared kfifo datatype
- * @size: size of the fifo buffer
+ * @size: size of the fifo buffer. Must be a power of two.
  *
  * Note1: the macro can be used inside struct or union declaration
  * Note2: the macro creates two objects:
@@ -86,12 +86,13 @@ union { \
  */
 #define INIT_KFIFO(name) \
        name = __kfifo_initializer(sizeof(name##kfifo_buffer) - \
-                               sizeof(struct kfifo), name##kfifo_buffer)
+                               sizeof(struct kfifo), \
+                               name##kfifo_buffer + sizeof(struct kfifo))
 
 /**
  * DEFINE_KFIFO - macro to define and initialize a kfifo
  * @name: name of the declared kfifo datatype
- * @size: size of the fifo buffer
+ * @size: size of the fifo buffer. Must be a power of two.
  *
  * Note1: the macro can be used for global and local kfifo data type variables
  * Note2: the macro creates two objects:
@@ -102,8 +103,6 @@ union { \
        unsigned char name##kfifo_buffer[size]; \
        struct kfifo name = __kfifo_initializer(size, name##kfifo_buffer)
 
-#undef __kfifo_initializer
-
 extern void kfifo_init(struct kfifo *fifo, void *buffer,
                        unsigned int size);
 extern __must_check int kfifo_alloc(struct kfifo *fifo, unsigned int size,
@@ -116,6 +115,16 @@ extern __must_check unsigned int kfifo_out(struct kfifo *fifo,
 extern __must_check unsigned int kfifo_out_peek(struct kfifo *fifo,
                                void *to, unsigned int len, unsigned offset);
 
+/**
+ * kfifo_initialized - Check if kfifo is initialized.
+ * @fifo: fifo to check
+ * Return %true if FIFO is initialized, otherwise %false.
+ * Assumes the fifo was 0 before.
+ */
+static inline bool kfifo_initialized(struct kfifo *fifo)
+{
+       return fifo->buffer != NULL;
+}
 
 /**
  * kfifo_reset - removes the entire FIFO contents
@@ -192,7 +201,7 @@ static inline __must_check unsigned int kfifo_avail(struct kfifo *fifo)
  * @n: the length of the data to be added.
  * @lock: pointer to the spinlock to use for locking.
  *
- * This function copies at most @len bytes from the @from buffer into
+ * This function copies at most @n bytes from the @from buffer into
  * the FIFO depending on the free space, and returns the number of
  * bytes copied.
  */
@@ -218,7 +227,7 @@ static inline unsigned int kfifo_in_locked(struct kfifo *fifo,
  * @n: the size of the destination buffer.
  * @lock: pointer to the spinlock to use for locking.
  *
- * This function copies at most @len bytes from the FIFO into the
+ * This function copies at most @n bytes from the FIFO into the
  * @to buffer and returns the number of copied bytes.
  */
 static inline __must_check unsigned int kfifo_out_locked(struct kfifo *fifo,