From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756382AbZHNLoZ (ORCPT ); Fri, 14 Aug 2009 07:44:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755159AbZHNLoZ (ORCPT ); Fri, 14 Aug 2009 07:44:25 -0400 Received: from www84.your-server.de ([213.133.104.84]:58805 "EHLO www84.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755148AbZHNLoY (ORCPT ); Fri, 14 Aug 2009 07:44:24 -0400 Subject: [PATCH 4/6] new kfifo API v0.3 - add DEFINE_KFIFO and friends, add very tiny functions From: Stefani Seibold To: linux-kernel Cc: Andrew Morton , Arnd Bergmann , Andi Kleen , Amerigo Wang Content-Type: text/plain Date: Fri, 14 Aug 2009 13:44:22 +0200 Message-Id: <1250250262.19690.95.camel@wall-e> Mime-Version: 1.0 X-Mailer: Evolution 2.26.3 Content-Transfer-Encoding: 7bit X-Authenticated-Sender: stefani@seibold.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is patch 4/6 of the new kfifo API: Add KFIFO_INIT - macro to generate a kfifo initializer Add DECLARE_KFIFO - macro to declare a kfifo and the associated buffer inside a struct Add INIT_KFIFO - macro to initialize a with DECLARE_KFIFO 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 kfifo.h | 90 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 88 insertions(+), 2 deletions(-) Signed-off-by: Stefani Seibold diff -u -N -r linux-2.6.31-rc4-kfifo4/include/linux/kfifo.h linux-2.6.31-rc4-kfifo5/include/linux/kfifo.h --- linux-2.6.31-rc4-kfifo4/include/linux/kfifo.h 2009-08-14 10:48:03.000000000 +0200 +++ linux-2.6.31-rc4-kfifo5/include/linux/kfifo.h 2009-08-14 11:53:52.000000000 +0200 @@ -32,6 +32,56 @@ unsigned int out; /* data is extracted from off. (out % size) */ }; +/* + * Macros for declaration and initialization of the kfifo datatype + */ + +/** + * KFIFO_INIT - macro to generate a kfifo initializer + * @s: size of the fifo buffer + * @b: address of the fifo buffer + */ +#define KFIFO_INIT(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 + */ +#define DECLARE_KFIFO(name, size) \ +union { \ + struct kfifo name; \ + unsigned char name##_buffer[size + sizeof(struct kfifo)]; \ +} + +/** + * INIT_KFIFO - macro to initialize a with DECLARE_KFIFO declared kfifo + * @name: name of the declared kfifo datatype + * @size: size of the fifo buffer + */ +#define INIT_KFIFO(name) \ + name = KFIFO_INIT(sizeof(name##_buffer) - sizeof(struct kfifo), \ + name##_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 + */ +#define DEFINE_KFIFO(name, size) \ + unsigned char name##_buffer[size]; \ + struct kfifo name = KFIFO_INIT(size, name##_buffer) + extern void kfifo_init(struct kfifo *fifo, unsigned char *buffer, unsigned int size); extern __must_check int kfifo_alloc(struct kfifo *fifo, @@ -52,6 +102,15 @@ } /** + * 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. */ @@ -65,6 +124,33 @@ } /** + * 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. @@ -114,8 +200,8 @@ * 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);