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Diffstat (limited to 'include/linux/kfifo.h')
-rw-r--r--include/linux/kfifo.h42
1 files changed, 24 insertions, 18 deletions
diff --git a/include/linux/kfifo.h b/include/linux/kfifo.h
index 7c6b32a1421c..6f6c5f300af6 100644
--- 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:
@@ -91,7 +91,7 @@ union { \
/**
* 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:
@@ -104,15 +104,28 @@ 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);
+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 != 0;
+}
/**
* kfifo_reset - removes the entire FIFO contents
@@ -194,7 +207,7 @@ 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 +232,7 @@ 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;
@@ -228,13 +241,6 @@ static inline __must_check unsigned int kfifo_out_locked(struct kfifo *fifo,
ret = kfifo_out(fifo, to, n);
- /*
- * optimization: if the FIFO is empty, set the indices to 0
- * so we don't wrap the next time
- */
- if (kfifo_is_empty(fifo))
- kfifo_reset(fifo);
-
spin_unlock_irqrestore(lock, flags);
return ret;
@@ -242,11 +248,11 @@ static inline __must_check unsigned int kfifo_out_locked(struct kfifo *fifo,
extern void kfifo_skip(struct kfifo *fifo, unsigned int len);
-extern __must_check unsigned int kfifo_from_user(struct kfifo *fifo,
- const void __user *from, unsigned int n);
+extern __must_check int kfifo_from_user(struct kfifo *fifo,
+ const void __user *from, unsigned int n, unsigned *lenout);
-extern __must_check unsigned int kfifo_to_user(struct kfifo *fifo,
- void __user *to, unsigned int n);
+extern __must_check int kfifo_to_user(struct kfifo *fifo,
+ void __user *to, unsigned int n, unsigned *lenout);
/*
* __kfifo_add_out internal helper function for updating the out offset