diff options
Diffstat (limited to 'include/linux/kfifo.h')
| -rw-r--r-- | include/linux/kfifo.h | 42 |
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 |