The patch titled kfifo: add DEFINE_KFIFO and friends, add very tiny functions has been added to the -mm tree. Its filename is kfifo-add-define_kfifo-and-friends-add-very-tiny-functions.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: kfifo: add DEFINE_KFIFO and friends, add very tiny functions From: Stefani Seibold <stefani@xxxxxxxxxxx> Add DECLARE_KFIFO - macro to declare a kfifo and the associated buffer inside a struct Add INIT_KFIFO - Initialize a kfifo declared by DECLARED_KFIFO Add DEFINE_KFIFO - macro to define and initialize a kfifo as a global or local object Add kfifo_size() - returns the size of the fifo in bytes Add kfifo_is_empty() - returns true if the fifo is empty Add kfifo_is_full() - returns true if the fifo is full Add kfifo_avail() - returns the number of bytes available in the FIFO Do some code cleanup Signed-off-by: Stefani Seibold <stefani@xxxxxxxxxxx> Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxx> Acked-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> Acked-by: Andi Kleen <ak@xxxxxxxxxxxxxxx> Acked-by: Arnd Bergmann <arnd@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/kfifo.h | 91 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 89 insertions(+), 2 deletions(-) diff -puN include/linux/kfifo.h~kfifo-add-define_kfifo-and-friends-add-very-tiny-functions include/linux/kfifo.h --- a/include/linux/kfifo.h~kfifo-add-define_kfifo-and-friends-add-very-tiny-functions +++ a/include/linux/kfifo.h @@ -51,6 +51,57 @@ struct kfifo { unsigned int out; /* data is extracted from off. (out % size) */ }; +/* + * Macros for declaration and initialization of the kfifo datatype + */ + +#define __kfifo_initializer(s, b) \ + (struct kfifo) { \ + .size = s, \ + .in = 0, \ + .out = 0, \ + .buffer = b \ + } + +/** + * DECLARE_KFIFO - macro to declare a kfifo and the associated buffer + * @name: name of the declared kfifo datatype + * @size: size of the fifo buffer + * + * Note: the macro can be used inside struct or union declaration + * Note: the macro creates two objects: + * A kfifo object with the given name and a buffer for the kfifo + * object named name##kfifo_buffer + */ +#define DECLARE_KFIFO(name, size) \ +union { \ + struct kfifo name; \ + unsigned char name##kfifo_buffer[size + sizeof(struct kfifo)]; \ +} + +/** + * INIT_KFIFO - Initialize a kfifo declared by DECLARED_KFIFO + * @name: name of the declared kfifo datatype + * @size: size of the fifo buffer + */ +#define INIT_KFIFO(name) \ + name = __kfifo_initializer(sizeof(name##kfifo_buffer) - \ + sizeof(struct kfifo), name##kfifo_buffer) + +/** + * DEFINE_KFIFO - macro to define and initialize a kfifo + * @name: name of the declared kfifo datatype + * @size: size of the fifo buffer + * + * Note: the macro can be used for global and local kfifo data type variables + * Note: the macro creates two objects: + * A kfifo object with the given name and a buffer for the kfifo + * object named name##kfifo_buffer + */ +#define DEFINE_KFIFO(name, size) \ + unsigned char name##kfifo_buffer[size]; \ + struct kfifo name = __kfifo_initializer(size, name##kfifo_buffer) + extern void kfifo_init(struct kfifo *fifo, unsigned char *buffer, unsigned int size); extern __must_check int kfifo_alloc(struct kfifo *fifo, unsigned int size, @@ -71,6 +122,15 @@ static inline void kfifo_reset(struct kf } /** + * kfifo_size - returns the size of the fifo in bytes + * @fifo: the fifo to be used. + */ +static inline __must_check unsigned int kfifo_size(struct kfifo *fifo) +{ + return fifo->size; +} + +/** * kfifo_len - returns the number of used bytes in the FIFO * @fifo: the fifo to be used. */ @@ -84,6 +144,33 @@ static inline unsigned int kfifo_len(str } /** + * kfifo_is_empty - returns true if the fifo is empty + * @fifo: the fifo to be used. + */ +static inline __must_check int kfifo_is_empty(struct kfifo *fifo) +{ + return fifo->in == fifo->out; +} + +/** + * kfifo_is_full - returns true if the fifo is full + * @fifo: the fifo to be used. + */ +static inline __must_check int kfifo_is_full(struct kfifo *fifo) +{ + return kfifo_len(fifo) == kfifo_size(fifo); +} + +/** + * kfifo_avail - returns the number of bytes available in the FIFO + * @fifo: the fifo to be used. + */ +static inline __must_check unsigned int kfifo_avail(struct kfifo *fifo) +{ + return kfifo_size(fifo) - kfifo_len(fifo); +} + +/** * kfifo_in_locked - puts some data into the FIFO using a spinlock for locking * @fifo: the fifo to be used. * @from: the data to be added. @@ -133,8 +220,8 @@ static inline __must_check unsigned int * optimization: if the FIFO is empty, set the indices to 0 * so we don't wrap the next time */ - if (fifo->in == fifo->out) - fifo->in = fifo->out = 0; + if (kfifo_is_empty(fifo)) + kfifo_reset(fifo); spin_unlock_irqrestore(lock, flags); _ Patches currently in -mm which might be from stefani@xxxxxxxxxxx are kfifo-move-struct-kfifo-in-place.patch kfifo-move-out-spinlock.patch kfifo-cleanup-namespace.patch kfifo-rename-kfifo_put-into-kfifo_in-and-kfifo_get-into-kfifo_out.patch kfifo-add-define_kfifo-and-friends-add-very-tiny-functions.patch kfifo-add-kfifo_skip-kfifo_from_user-and-kfifo_to_user.patch kfifo-add-record-handling-functions.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html