* Re: [PATCH 1/4] fix kfifo miss use of nozami.c
2010-02-12 7:52 [PATCH 0/4] enhanced reimplemention of the kfifo API Stefani Seibold
@ 2010-02-12 7:56 ` Stefani Seibold
2010-02-12 7:58 ` [PATCH 2/4] remove the old non generic API Stefani Seibold
` (3 subsequent siblings)
4 siblings, 0 replies; 13+ messages in thread
From: Stefani Seibold @ 2010-02-12 7:56 UTC (permalink / raw)
To: linux-kernel
Cc: Andrew Morton, Andi Kleen, Greg Kroah-Hartman, Alan Cox,
Theodore Tso, Ira W. Snyder
User of the kernel fifo should never bypass the API and directly access
the fifo structure. Otherwise it will be very hard to maintain the API.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
---
drivers/char/nozomi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -u -N -r -p linux-2.6.33-rc7.dummy/drivers/char/nozomi.c linux-2.6.33-rc7.new/drivers/char/nozomi.c
--- linux-2.6.33-rc7.dummy/drivers/char/nozomi.c 2010-02-11 17:05:50.670990421 +0100
+++ linux-2.6.33-rc7.new/drivers/char/nozomi.c 2010-02-11 17:11:20.350865181 +0100
@@ -1743,7 +1743,7 @@ static int ntty_write_room(struct tty_st
if (!port->port.count)
goto exit;
- room = port->fifo_ul.size - kfifo_len(&port->fifo_ul);
+ room = kfifo_avail(&port->fifo_ul);
exit:
mutex_unlock(&port->tty_sem);
^ permalink raw reply [flat|nested] 13+ messages in thread* Re: [PATCH 2/4] remove the old non generic API
2010-02-12 7:52 [PATCH 0/4] enhanced reimplemention of the kfifo API Stefani Seibold
2010-02-12 7:56 ` [PATCH 1/4] fix kfifo miss use of nozami.c Stefani Seibold
@ 2010-02-12 7:58 ` Stefani Seibold
2010-02-12 8:03 ` [PATCH 3/4] add the new generic kfifo API Stefani Seibold
` (2 subsequent siblings)
4 siblings, 0 replies; 13+ messages in thread
From: Stefani Seibold @ 2010-02-12 7:58 UTC (permalink / raw)
To: linux-kernel
Cc: Andrew Morton, Andi Kleen, Greg Kroah-Hartman, Alan Cox,
Theodore Tso, Ira W. Snyder
This patch simple remove the whole kfifo.c and kfifo.h files. The next
patch will replace it with the new generic kfifo API.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
---
include/linux/kfifo.h | 616 --------------------------------------------------
kernel/kfifo.c | 444 ------------------------------------
2 files changed, 1060 deletions(-)
diff -u -N -r -p linux-2.6.33-rc7.orig/include/linux/kfifo.h linux-2.6.33-rc7.dummy/include/linux/kfifo.h
--- linux-2.6.33-rc7.orig/include/linux/kfifo.h 2010-02-11 17:05:56.639742567 +0100
+++ linux-2.6.33-rc7.dummy/include/linux/kfifo.h 1970-01-01 01:00:00.000000000 +0100
@@ -1,616 +0,0 @@
-/*
- * A generic kernel FIFO implementation.
- *
- * Copyright (C) 2009 Stefani Seibold <stefani@seibold.net>
- * Copyright (C) 2004 Stelian Pop <stelian@popies.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- */
-
-/*
- * Howto porting drivers to the new generic fifo API:
- *
- * - Modify the declaration of the "struct kfifo *" object into a
- * in-place "struct kfifo" object
- * - Init the in-place object with kfifo_alloc() or kfifo_init()
- * Note: The address of the in-place "struct kfifo" object must be
- * passed as the first argument to this functions
- * - Replace the use of __kfifo_put into kfifo_in and __kfifo_get
- * into kfifo_out
- * - Replace the use of kfifo_put into kfifo_in_locked and kfifo_get
- * into kfifo_out_locked
- * Note: the spinlock pointer formerly passed to kfifo_init/kfifo_alloc
- * must be passed now to the kfifo_in_locked and kfifo_out_locked
- * as the last parameter.
- * - All formerly name __kfifo_* functions has been renamed into kfifo_*
- */
-
-#ifndef _LINUX_KFIFO_H
-#define _LINUX_KFIFO_H
-
-#include <linux/kernel.h>
-#include <linux/spinlock.h>
-
-struct kfifo {
- unsigned char *buffer; /* the buffer holding the data */
- unsigned int size; /* the size of the allocated buffer */
- unsigned int in; /* data is added at offset (in % size) */
- unsigned int out; /* data is extracted from off. (out % size) */
-};
-
-/*
- * Macros for declaration and initialization of the kfifo datatype
- */
-
-/* helper macro */
-#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. Must be a power of two.
- *
- * Note1: the macro can be used inside struct or union declaration
- * Note2: 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 DECLARE_KFIFO
- * @name: name of the declared kfifo datatype
- */
-#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. 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:
- * 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)
-
-#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,
- gfp_t gfp_mask);
-extern void kfifo_free(struct kfifo *fifo);
-extern unsigned int kfifo_in(struct kfifo *fifo,
- const void *from, unsigned int len);
-extern __must_check unsigned int kfifo_out(struct kfifo *fifo,
- 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
- * @fifo: the fifo to be emptied.
- */
-static inline void kfifo_reset(struct kfifo *fifo)
-{
- fifo->in = fifo->out = 0;
-}
-
-/**
- * kfifo_reset_out - skip FIFO contents
- * @fifo: the fifo to be emptied.
- */
-static inline void kfifo_reset_out(struct kfifo *fifo)
-{
- smp_mb();
- fifo->out = fifo->in;
-}
-
-/**
- * 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.
- */
-static inline unsigned int kfifo_len(struct kfifo *fifo)
-{
- register unsigned int out;
-
- out = fifo->out;
- smp_rmb();
- return fifo->in - out;
-}
-
-/**
- * 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.
- * @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
- * the FIFO depending on the free space, and returns the number of
- * bytes copied.
- */
-static inline unsigned int kfifo_in_locked(struct kfifo *fifo,
- const void *from, unsigned int n, spinlock_t *lock)
-{
- unsigned long flags;
- unsigned int ret;
-
- spin_lock_irqsave(lock, flags);
-
- ret = kfifo_in(fifo, from, n);
-
- spin_unlock_irqrestore(lock, flags);
-
- return ret;
-}
-
-/**
- * kfifo_out_locked - gets some data from the FIFO using a spinlock for locking
- * @fifo: the fifo to be used.
- * @to: where the data must be copied.
- * @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
- * @to buffer and returns the number of copied bytes.
- */
-static inline __must_check unsigned int kfifo_out_locked(struct kfifo *fifo,
- void *to, unsigned int n, spinlock_t *lock)
-{
- unsigned long flags;
- unsigned int ret;
-
- spin_lock_irqsave(lock, flags);
-
- ret = kfifo_out(fifo, to, n);
-
- spin_unlock_irqrestore(lock, flags);
-
- return ret;
-}
-
-extern void kfifo_skip(struct kfifo *fifo, unsigned int len);
-
-extern __must_check int kfifo_from_user(struct kfifo *fifo,
- const void __user *from, unsigned int n, unsigned *lenout);
-
-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
- */
-static inline void __kfifo_add_out(struct kfifo *fifo,
- unsigned int off)
-{
- smp_mb();
- fifo->out += off;
-}
-
-/*
- * __kfifo_add_in internal helper function for updating the in offset
- */
-static inline void __kfifo_add_in(struct kfifo *fifo,
- unsigned int off)
-{
- smp_wmb();
- fifo->in += off;
-}
-
-/*
- * __kfifo_off internal helper function for calculating the index of a
- * given offeset
- */
-static inline unsigned int __kfifo_off(struct kfifo *fifo, unsigned int off)
-{
- return off & (fifo->size - 1);
-}
-
-/*
- * __kfifo_peek_n internal helper function for determinate the length of
- * the next record in the fifo
- */
-static inline unsigned int __kfifo_peek_n(struct kfifo *fifo,
- unsigned int recsize)
-{
-#define __KFIFO_GET(fifo, off, shift) \
- ((fifo)->buffer[__kfifo_off((fifo), (fifo)->out+(off))] << (shift))
-
- unsigned int l;
-
- l = __KFIFO_GET(fifo, 0, 0);
-
- if (--recsize)
- l |= __KFIFO_GET(fifo, 1, 8);
-
- return l;
-#undef __KFIFO_GET
-}
-
-/*
- * __kfifo_poke_n internal helper function for storing the length of
- * the next record into the fifo
- */
-static inline void __kfifo_poke_n(struct kfifo *fifo,
- unsigned int recsize, unsigned int n)
-{
-#define __KFIFO_PUT(fifo, off, val, shift) \
- ( \
- (fifo)->buffer[__kfifo_off((fifo), (fifo)->in+(off))] = \
- (unsigned char)((val) >> (shift)) \
- )
-
- __KFIFO_PUT(fifo, 0, n, 0);
-
- if (--recsize)
- __KFIFO_PUT(fifo, 1, n, 8);
-#undef __KFIFO_PUT
-}
-
-/*
- * __kfifo_in_... internal functions for put date into the fifo
- * do not call it directly, use kfifo_in_rec() instead
- */
-extern unsigned int __kfifo_in_n(struct kfifo *fifo,
- const void *from, unsigned int n, unsigned int recsize);
-
-extern unsigned int __kfifo_in_generic(struct kfifo *fifo,
- const void *from, unsigned int n, unsigned int recsize);
-
-static inline unsigned int __kfifo_in_rec(struct kfifo *fifo,
- const void *from, unsigned int n, unsigned int recsize)
-{
- unsigned int ret;
-
- ret = __kfifo_in_n(fifo, from, n, recsize);
-
- if (likely(ret == 0)) {
- if (recsize)
- __kfifo_poke_n(fifo, recsize, n);
- __kfifo_add_in(fifo, n + recsize);
- }
- return ret;
-}
-
-/**
- * kfifo_in_rec - puts some record data into the FIFO
- * @fifo: the fifo to be used.
- * @from: the data to be added.
- * @n: the length of the data to be added.
- * @recsize: size of record field
- *
- * This function copies @n bytes from the @from into the FIFO and returns
- * the number of bytes which cannot be copied.
- * A returned value greater than the @n value means that the record doesn't
- * fit into the buffer.
- *
- * Note that with only one concurrent reader and one concurrent
- * writer, you don't need extra locking to use these functions.
- */
-static inline __must_check unsigned int kfifo_in_rec(struct kfifo *fifo,
- void *from, unsigned int n, unsigned int recsize)
-{
- if (!__builtin_constant_p(recsize))
- return __kfifo_in_generic(fifo, from, n, recsize);
- return __kfifo_in_rec(fifo, from, n, recsize);
-}
-
-/*
- * __kfifo_out_... internal functions for get date from the fifo
- * do not call it directly, use kfifo_out_rec() instead
- */
-extern unsigned int __kfifo_out_n(struct kfifo *fifo,
- void *to, unsigned int reclen, unsigned int recsize);
-
-extern unsigned int __kfifo_out_generic(struct kfifo *fifo,
- void *to, unsigned int n,
- unsigned int recsize, unsigned int *total);
-
-static inline unsigned int __kfifo_out_rec(struct kfifo *fifo,
- void *to, unsigned int n, unsigned int recsize,
- unsigned int *total)
-{
- unsigned int l;
-
- if (!recsize) {
- l = n;
- if (total)
- *total = l;
- } else {
- l = __kfifo_peek_n(fifo, recsize);
- if (total)
- *total = l;
- if (n < l)
- return l;
- }
-
- return __kfifo_out_n(fifo, to, l, recsize);
-}
-
-/**
- * kfifo_out_rec - gets some record data from the FIFO
- * @fifo: the fifo to be used.
- * @to: where the data must be copied.
- * @n: the size of the destination buffer.
- * @recsize: size of record field
- * @total: pointer where the total number of to copied bytes should stored
- *
- * This function copies at most @n bytes from the FIFO to @to and returns the
- * number of bytes which cannot be copied.
- * A returned value greater than the @n value means that the record doesn't
- * fit into the @to buffer.
- *
- * Note that with only one concurrent reader and one concurrent
- * writer, you don't need extra locking to use these functions.
- */
-static inline __must_check unsigned int kfifo_out_rec(struct kfifo *fifo,
- void *to, unsigned int n, unsigned int recsize,
- unsigned int *total)
-
-{
- if (!__builtin_constant_p(recsize))
- return __kfifo_out_generic(fifo, to, n, recsize, total);
- return __kfifo_out_rec(fifo, to, n, recsize, total);
-}
-
-/*
- * __kfifo_from_user_... internal functions for transfer from user space into
- * the fifo. do not call it directly, use kfifo_from_user_rec() instead
- */
-extern unsigned int __kfifo_from_user_n(struct kfifo *fifo,
- const void __user *from, unsigned int n, unsigned int recsize);
-
-extern unsigned int __kfifo_from_user_generic(struct kfifo *fifo,
- const void __user *from, unsigned int n, unsigned int recsize);
-
-static inline unsigned int __kfifo_from_user_rec(struct kfifo *fifo,
- const void __user *from, unsigned int n, unsigned int recsize)
-{
- unsigned int ret;
-
- ret = __kfifo_from_user_n(fifo, from, n, recsize);
-
- if (likely(ret == 0)) {
- if (recsize)
- __kfifo_poke_n(fifo, recsize, n);
- __kfifo_add_in(fifo, n + recsize);
- }
- return ret;
-}
-
-/**
- * kfifo_from_user_rec - puts some data from user space into the FIFO
- * @fifo: the fifo to be used.
- * @from: pointer to the data to be added.
- * @n: the length of the data to be added.
- * @recsize: size of record field
- *
- * This function copies @n bytes from the @from into the
- * FIFO and returns the number of bytes which cannot be copied.
- *
- * If the returned value is equal or less the @n value, the copy_from_user()
- * functions has failed. Otherwise the record doesn't fit into the buffer.
- *
- * Note that with only one concurrent reader and one concurrent
- * writer, you don't need extra locking to use these functions.
- */
-static inline __must_check unsigned int kfifo_from_user_rec(struct kfifo *fifo,
- const void __user *from, unsigned int n, unsigned int recsize)
-{
- if (!__builtin_constant_p(recsize))
- return __kfifo_from_user_generic(fifo, from, n, recsize);
- return __kfifo_from_user_rec(fifo, from, n, recsize);
-}
-
-/*
- * __kfifo_to_user_... internal functions for transfer fifo data into user space
- * do not call it directly, use kfifo_to_user_rec() instead
- */
-extern unsigned int __kfifo_to_user_n(struct kfifo *fifo,
- void __user *to, unsigned int n, unsigned int reclen,
- unsigned int recsize);
-
-extern unsigned int __kfifo_to_user_generic(struct kfifo *fifo,
- void __user *to, unsigned int n, unsigned int recsize,
- unsigned int *total);
-
-static inline unsigned int __kfifo_to_user_rec(struct kfifo *fifo,
- void __user *to, unsigned int n,
- unsigned int recsize, unsigned int *total)
-{
- unsigned int l;
-
- if (!recsize) {
- l = n;
- if (total)
- *total = l;
- } else {
- l = __kfifo_peek_n(fifo, recsize);
- if (total)
- *total = l;
- if (n < l)
- return l;
- }
-
- return __kfifo_to_user_n(fifo, to, n, l, recsize);
-}
-
-/**
- * kfifo_to_user_rec - gets data from the FIFO and write it to user space
- * @fifo: the fifo to be used.
- * @to: where the data must be copied.
- * @n: the size of the destination buffer.
- * @recsize: size of record field
- * @total: pointer where the total number of to copied bytes should stored
- *
- * This function copies at most @n bytes from the FIFO to the @to.
- * In case of an error, the function returns the number of bytes which cannot
- * be copied.
- * If the returned value is equal or less the @n value, the copy_to_user()
- * functions has failed. Otherwise the record doesn't fit into the @to buffer.
- *
- * Note that with only one concurrent reader and one concurrent
- * writer, you don't need extra locking to use these functions.
- */
-static inline __must_check unsigned int kfifo_to_user_rec(struct kfifo *fifo,
- void __user *to, unsigned int n, unsigned int recsize,
- unsigned int *total)
-{
- if (!__builtin_constant_p(recsize))
- return __kfifo_to_user_generic(fifo, to, n, recsize, total);
- return __kfifo_to_user_rec(fifo, to, n, recsize, total);
-}
-
-/*
- * __kfifo_peek_... internal functions for peek into the next fifo record
- * do not call it directly, use kfifo_peek_rec() instead
- */
-extern unsigned int __kfifo_peek_generic(struct kfifo *fifo,
- unsigned int recsize);
-
-/**
- * kfifo_peek_rec - gets the size of the next FIFO record data
- * @fifo: the fifo to be used.
- * @recsize: size of record field
- *
- * This function returns the size of the next FIFO record in number of bytes
- */
-static inline __must_check unsigned int kfifo_peek_rec(struct kfifo *fifo,
- unsigned int recsize)
-{
- if (!__builtin_constant_p(recsize))
- return __kfifo_peek_generic(fifo, recsize);
- if (!recsize)
- return kfifo_len(fifo);
- return __kfifo_peek_n(fifo, recsize);
-}
-
-/*
- * __kfifo_skip_... internal functions for skip the next fifo record
- * do not call it directly, use kfifo_skip_rec() instead
- */
-extern void __kfifo_skip_generic(struct kfifo *fifo, unsigned int recsize);
-
-static inline void __kfifo_skip_rec(struct kfifo *fifo,
- unsigned int recsize)
-{
- unsigned int l;
-
- if (recsize) {
- l = __kfifo_peek_n(fifo, recsize);
-
- if (l + recsize <= kfifo_len(fifo)) {
- __kfifo_add_out(fifo, l + recsize);
- return;
- }
- }
- kfifo_reset_out(fifo);
-}
-
-/**
- * kfifo_skip_rec - skip the next fifo out record
- * @fifo: the fifo to be used.
- * @recsize: size of record field
- *
- * This function skips the next FIFO record
- */
-static inline void kfifo_skip_rec(struct kfifo *fifo,
- unsigned int recsize)
-{
- if (!__builtin_constant_p(recsize))
- __kfifo_skip_generic(fifo, recsize);
- else
- __kfifo_skip_rec(fifo, recsize);
-}
-
-/**
- * kfifo_avail_rec - returns the number of bytes available in a record FIFO
- * @fifo: the fifo to be used.
- * @recsize: size of record field
- */
-static inline __must_check unsigned int kfifo_avail_rec(struct kfifo *fifo,
- unsigned int recsize)
-{
- unsigned int l = kfifo_size(fifo) - kfifo_len(fifo);
-
- return (l > recsize) ? l - recsize : 0;
-}
-
-#endif
diff -u -N -r -p linux-2.6.33-rc7.orig/kernel/kfifo.c linux-2.6.33-rc7.dummy/kernel/kfifo.c
--- linux-2.6.33-rc7.orig/kernel/kfifo.c 2010-02-11 17:05:57.076578709 +0100
+++ linux-2.6.33-rc7.dummy/kernel/kfifo.c 1970-01-01 01:00:00.000000000 +0100
@@ -1,444 +0,0 @@
-/*
- * A generic kernel FIFO implementation.
- *
- * Copyright (C) 2009 Stefani Seibold <stefani@seibold.net>
- * Copyright (C) 2004 Stelian Pop <stelian@popies.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/err.h>
-#include <linux/kfifo.h>
-#include <linux/log2.h>
-#include <linux/uaccess.h>
-
-static void _kfifo_init(struct kfifo *fifo, void *buffer,
- unsigned int size)
-{
- fifo->buffer = buffer;
- fifo->size = size;
-
- kfifo_reset(fifo);
-}
-
-/**
- * kfifo_init - initialize a FIFO using a preallocated buffer
- * @fifo: the fifo to assign the buffer
- * @buffer: the preallocated buffer to be used.
- * @size: the size of the internal buffer, this has to be a power of 2.
- *
- */
-void kfifo_init(struct kfifo *fifo, void *buffer, unsigned int size)
-{
- /* size must be a power of 2 */
- BUG_ON(!is_power_of_2(size));
-
- _kfifo_init(fifo, buffer, size);
-}
-EXPORT_SYMBOL(kfifo_init);
-
-/**
- * kfifo_alloc - allocates a new FIFO internal buffer
- * @fifo: the fifo to assign then new buffer
- * @size: the size of the buffer to be allocated, this have to be a power of 2.
- * @gfp_mask: get_free_pages mask, passed to kmalloc()
- *
- * This function dynamically allocates a new fifo internal buffer
- *
- * The size will be rounded-up to a power of 2.
- * The buffer will be release with kfifo_free().
- * Return 0 if no error, otherwise the an error code
- */
-int kfifo_alloc(struct kfifo *fifo, unsigned int size, gfp_t gfp_mask)
-{
- unsigned char *buffer;
-
- /*
- * round up to the next power of 2, since our 'let the indices
- * wrap' technique works only in this case.
- */
- if (!is_power_of_2(size)) {
- BUG_ON(size > 0x80000000);
- size = roundup_pow_of_two(size);
- }
-
- buffer = kmalloc(size, gfp_mask);
- if (!buffer) {
- _kfifo_init(fifo, 0, 0);
- return -ENOMEM;
- }
-
- _kfifo_init(fifo, buffer, size);
-
- return 0;
-}
-EXPORT_SYMBOL(kfifo_alloc);
-
-/**
- * kfifo_free - frees the FIFO internal buffer
- * @fifo: the fifo to be freed.
- */
-void kfifo_free(struct kfifo *fifo)
-{
- kfree(fifo->buffer);
-}
-EXPORT_SYMBOL(kfifo_free);
-
-/**
- * kfifo_skip - skip output data
- * @fifo: the fifo to be used.
- * @len: number of bytes to skip
- */
-void kfifo_skip(struct kfifo *fifo, unsigned int len)
-{
- if (len < kfifo_len(fifo)) {
- __kfifo_add_out(fifo, len);
- return;
- }
- kfifo_reset_out(fifo);
-}
-EXPORT_SYMBOL(kfifo_skip);
-
-static inline void __kfifo_in_data(struct kfifo *fifo,
- const void *from, unsigned int len, unsigned int off)
-{
- unsigned int l;
-
- /*
- * Ensure that we sample the fifo->out index -before- we
- * start putting bytes into the kfifo.
- */
-
- smp_mb();
-
- off = __kfifo_off(fifo, fifo->in + off);
-
- /* first put the data starting from fifo->in to buffer end */
- l = min(len, fifo->size - off);
- memcpy(fifo->buffer + off, from, l);
-
- /* then put the rest (if any) at the beginning of the buffer */
- memcpy(fifo->buffer, from + l, len - l);
-}
-
-static inline void __kfifo_out_data(struct kfifo *fifo,
- void *to, unsigned int len, unsigned int off)
-{
- unsigned int l;
-
- /*
- * Ensure that we sample the fifo->in index -before- we
- * start removing bytes from the kfifo.
- */
-
- smp_rmb();
-
- off = __kfifo_off(fifo, fifo->out + off);
-
- /* first get the data from fifo->out until the end of the buffer */
- l = min(len, fifo->size - off);
- memcpy(to, fifo->buffer + off, l);
-
- /* then get the rest (if any) from the beginning of the buffer */
- memcpy(to + l, fifo->buffer, len - l);
-}
-
-static inline int __kfifo_from_user_data(struct kfifo *fifo,
- const void __user *from, unsigned int len, unsigned int off,
- unsigned *lenout)
-{
- unsigned int l;
- int ret;
-
- /*
- * Ensure that we sample the fifo->out index -before- we
- * start putting bytes into the kfifo.
- */
-
- smp_mb();
-
- off = __kfifo_off(fifo, fifo->in + off);
-
- /* first put the data starting from fifo->in to buffer end */
- l = min(len, fifo->size - off);
- ret = copy_from_user(fifo->buffer + off, from, l);
- if (unlikely(ret)) {
- *lenout = ret;
- return -EFAULT;
- }
- *lenout = l;
-
- /* then put the rest (if any) at the beginning of the buffer */
- ret = copy_from_user(fifo->buffer, from + l, len - l);
- *lenout += ret ? ret : len - l;
- return ret ? -EFAULT : 0;
-}
-
-static inline int __kfifo_to_user_data(struct kfifo *fifo,
- void __user *to, unsigned int len, unsigned int off, unsigned *lenout)
-{
- unsigned int l;
- int ret;
-
- /*
- * Ensure that we sample the fifo->in index -before- we
- * start removing bytes from the kfifo.
- */
-
- smp_rmb();
-
- off = __kfifo_off(fifo, fifo->out + off);
-
- /* first get the data from fifo->out until the end of the buffer */
- l = min(len, fifo->size - off);
- ret = copy_to_user(to, fifo->buffer + off, l);
- *lenout = l;
- if (unlikely(ret)) {
- *lenout -= ret;
- return -EFAULT;
- }
-
- /* then get the rest (if any) from the beginning of the buffer */
- len -= l;
- ret = copy_to_user(to + l, fifo->buffer, len);
- if (unlikely(ret)) {
- *lenout += len - ret;
- return -EFAULT;
- }
- *lenout += len;
- return 0;
-}
-
-unsigned int __kfifo_in_n(struct kfifo *fifo,
- const void *from, unsigned int len, unsigned int recsize)
-{
- if (kfifo_avail(fifo) < len + recsize)
- return len + 1;
-
- __kfifo_in_data(fifo, from, len, recsize);
- return 0;
-}
-EXPORT_SYMBOL(__kfifo_in_n);
-
-/**
- * kfifo_in - puts some data into the FIFO
- * @fifo: the fifo to be used.
- * @from: the data to be added.
- * @len: the length of the data to be added.
- *
- * This function copies at most @len bytes from the @from buffer into
- * the FIFO depending on the free space, and returns the number of
- * bytes copied.
- *
- * Note that with only one concurrent reader and one concurrent
- * writer, you don't need extra locking to use these functions.
- */
-unsigned int kfifo_in(struct kfifo *fifo, const void *from,
- unsigned int len)
-{
- len = min(kfifo_avail(fifo), len);
-
- __kfifo_in_data(fifo, from, len, 0);
- __kfifo_add_in(fifo, len);
- return len;
-}
-EXPORT_SYMBOL(kfifo_in);
-
-unsigned int __kfifo_in_generic(struct kfifo *fifo,
- const void *from, unsigned int len, unsigned int recsize)
-{
- return __kfifo_in_rec(fifo, from, len, recsize);
-}
-EXPORT_SYMBOL(__kfifo_in_generic);
-
-unsigned int __kfifo_out_n(struct kfifo *fifo,
- void *to, unsigned int len, unsigned int recsize)
-{
- if (kfifo_len(fifo) < len + recsize)
- return len;
-
- __kfifo_out_data(fifo, to, len, recsize);
- __kfifo_add_out(fifo, len + recsize);
- return 0;
-}
-EXPORT_SYMBOL(__kfifo_out_n);
-
-/**
- * kfifo_out - gets some data from the FIFO
- * @fifo: the fifo to be used.
- * @to: where the data must be copied.
- * @len: the size of the destination buffer.
- *
- * This function copies at most @len bytes from the FIFO into the
- * @to buffer and returns the number of copied bytes.
- *
- * Note that with only one concurrent reader and one concurrent
- * writer, you don't need extra locking to use these functions.
- */
-unsigned int kfifo_out(struct kfifo *fifo, void *to, unsigned int len)
-{
- len = min(kfifo_len(fifo), len);
-
- __kfifo_out_data(fifo, to, len, 0);
- __kfifo_add_out(fifo, len);
-
- return len;
-}
-EXPORT_SYMBOL(kfifo_out);
-
-/**
- * kfifo_out_peek - copy some data from the FIFO, but do not remove it
- * @fifo: the fifo to be used.
- * @to: where the data must be copied.
- * @len: the size of the destination buffer.
- * @offset: offset into the fifo
- *
- * This function copies at most @len bytes at @offset from the FIFO
- * into the @to buffer and returns the number of copied bytes.
- * The data is not removed from the FIFO.
- */
-unsigned int kfifo_out_peek(struct kfifo *fifo, void *to, unsigned int len,
- unsigned offset)
-{
- len = min(kfifo_len(fifo), len + offset);
-
- __kfifo_out_data(fifo, to, len, offset);
- return len;
-}
-EXPORT_SYMBOL(kfifo_out_peek);
-
-unsigned int __kfifo_out_generic(struct kfifo *fifo,
- void *to, unsigned int len, unsigned int recsize,
- unsigned int *total)
-{
- return __kfifo_out_rec(fifo, to, len, recsize, total);
-}
-EXPORT_SYMBOL(__kfifo_out_generic);
-
-unsigned int __kfifo_from_user_n(struct kfifo *fifo,
- const void __user *from, unsigned int len, unsigned int recsize)
-{
- unsigned total;
-
- if (kfifo_avail(fifo) < len + recsize)
- return len + 1;
-
- __kfifo_from_user_data(fifo, from, len, recsize, &total);
- return total;
-}
-EXPORT_SYMBOL(__kfifo_from_user_n);
-
-/**
- * kfifo_from_user - puts some data from user space into the FIFO
- * @fifo: the fifo to be used.
- * @from: pointer to the data to be added.
- * @len: the length of the data to be added.
- * @total: the actual returned data length.
- *
- * This function copies at most @len bytes from the @from into the
- * FIFO depending and returns -EFAULT/0.
- *
- * Note that with only one concurrent reader and one concurrent
- * writer, you don't need extra locking to use these functions.
- */
-int kfifo_from_user(struct kfifo *fifo,
- const void __user *from, unsigned int len, unsigned *total)
-{
- int ret;
- len = min(kfifo_avail(fifo), len);
- ret = __kfifo_from_user_data(fifo, from, len, 0, total);
- if (ret)
- return ret;
- __kfifo_add_in(fifo, len);
- return 0;
-}
-EXPORT_SYMBOL(kfifo_from_user);
-
-unsigned int __kfifo_from_user_generic(struct kfifo *fifo,
- const void __user *from, unsigned int len, unsigned int recsize)
-{
- return __kfifo_from_user_rec(fifo, from, len, recsize);
-}
-EXPORT_SYMBOL(__kfifo_from_user_generic);
-
-unsigned int __kfifo_to_user_n(struct kfifo *fifo,
- void __user *to, unsigned int len, unsigned int reclen,
- unsigned int recsize)
-{
- unsigned int ret, total;
-
- if (kfifo_len(fifo) < reclen + recsize)
- return len;
-
- ret = __kfifo_to_user_data(fifo, to, reclen, recsize, &total);
-
- if (likely(ret == 0))
- __kfifo_add_out(fifo, reclen + recsize);
-
- return total;
-}
-EXPORT_SYMBOL(__kfifo_to_user_n);
-
-/**
- * kfifo_to_user - gets data from the FIFO and write it to user space
- * @fifo: the fifo to be used.
- * @to: where the data must be copied.
- * @len: the size of the destination buffer.
- * @lenout: pointer to output variable with copied data
- *
- * This function copies at most @len bytes from the FIFO into the
- * @to buffer and 0 or -EFAULT.
- *
- * Note that with only one concurrent reader and one concurrent
- * writer, you don't need extra locking to use these functions.
- */
-int kfifo_to_user(struct kfifo *fifo,
- void __user *to, unsigned int len, unsigned *lenout)
-{
- int ret;
- len = min(kfifo_len(fifo), len);
- ret = __kfifo_to_user_data(fifo, to, len, 0, lenout);
- __kfifo_add_out(fifo, *lenout);
- return ret;
-}
-EXPORT_SYMBOL(kfifo_to_user);
-
-unsigned int __kfifo_to_user_generic(struct kfifo *fifo,
- void __user *to, unsigned int len, unsigned int recsize,
- unsigned int *total)
-{
- return __kfifo_to_user_rec(fifo, to, len, recsize, total);
-}
-EXPORT_SYMBOL(__kfifo_to_user_generic);
-
-unsigned int __kfifo_peek_generic(struct kfifo *fifo, unsigned int recsize)
-{
- if (recsize == 0)
- return kfifo_avail(fifo);
-
- return __kfifo_peek_n(fifo, recsize);
-}
-EXPORT_SYMBOL(__kfifo_peek_generic);
-
-void __kfifo_skip_generic(struct kfifo *fifo, unsigned int recsize)
-{
- __kfifo_skip_rec(fifo, recsize);
-}
-EXPORT_SYMBOL(__kfifo_skip_generic);
-
^ permalink raw reply [flat|nested] 13+ messages in thread* Re: [PATCH 3/4] add the new generic kfifo API
2010-02-12 7:52 [PATCH 0/4] enhanced reimplemention of the kfifo API Stefani Seibold
2010-02-12 7:56 ` [PATCH 1/4] fix kfifo miss use of nozami.c Stefani Seibold
2010-02-12 7:58 ` [PATCH 2/4] remove the old non generic API Stefani Seibold
@ 2010-02-12 8:03 ` Stefani Seibold
2010-02-12 8:07 ` [PATCH 4/4] add example files to the kernel sample directory Stefani Seibold
2010-02-19 9:39 ` Enhanced reimplemention of the kfifo API request for merge Stefani Seibold
4 siblings, 0 replies; 13+ messages in thread
From: Stefani Seibold @ 2010-02-12 8:03 UTC (permalink / raw)
To: linux-kernel
Cc: Andrew Morton, Andi Kleen, Greg Kroah-Hartman, Alan Cox,
Theodore Tso, Ira W. Snyder
Replace the old kfifo API files kfifo.c and kfifo.h with the new generic
version and fix the kerneldoc API template file.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
---
Documentation/DocBook/kernel-api.tmpl | 1
include/linux/kfifo.h | 845 ++++++++++++++++++++++++++++++++++
kernel/kfifo.c | 603 ++++++++++++++++++++++++
3 files changed, 1448 insertions(+), 1 deletion(-)
diff -u -N -r -p linux-2.6.33-rc7.dummy/Documentation/DocBook/kernel-api.tmpl linux-2.6.33-rc7.new/Documentation/DocBook/kernel-api.tmpl
--- linux-2.6.33-rc7.dummy/Documentation/DocBook/kernel-api.tmpl 2009-12-03 04:51:21.000000000 +0100
+++ linux-2.6.33-rc7.new/Documentation/DocBook/kernel-api.tmpl 2010-02-11 17:12:02.266996831 +0100
@@ -132,7 +132,6 @@ X!Ilib/string.c
<title>FIFO Buffer</title>
<sect1><title>kfifo interface</title>
!Iinclude/linux/kfifo.h
-!Ekernel/kfifo.c
</sect1>
</chapter>
diff -u -N -r -p linux-2.6.33-rc7.dummy/include/linux/kfifo.h linux-2.6.33-rc7.new/include/linux/kfifo.h
--- linux-2.6.33-rc7.dummy/include/linux/kfifo.h 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.33-rc7.new/include/linux/kfifo.h 2010-02-11 17:08:54.725651713 +0100
@@ -0,0 +1,845 @@
+/*
+ * A generic kernel FIFO implementation
+ *
+ * Copyright (C) 2009/2010 Stefani Seibold <stefani@seibold.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#ifndef _LINUX_KFIFO_H
+#define _LINUX_KFIFO_H
+
+/*
+ * How to porting drivers to the new generic FIFO API:
+ *
+ * - Modify the declaration of the "struct kfifo *" object into a
+ * in-place "struct kfifo" object
+ * - Init the in-place object with kfifo_alloc() or kfifo_init()
+ * Note: The address of the in-place "struct kfifo" object must be
+ * passed as the first argument to this functions
+ * - Replace the use of __kfifo_put into kfifo_in and __kfifo_get
+ * into kfifo_out
+ * - Replace the use of kfifo_put into kfifo_in_spinlocked and kfifo_get
+ * into kfifo_out_spinlocked
+ * Note: the spinlock pointer formerly passed to kfifo_init/kfifo_alloc
+ * must be passed now to the kfifo_in_spinlocked and kfifo_out_spinlocked
+ * as the last parameter
+ * - The formerly __kfifo_* functions are renamed into kfifo_*
+ */
+
+/*
+ * Note about locking : There is no locking required until only * one reader
+ * and one writer is using the fifo and no kfifo_reset() will be * called
+ * kfifo_reset_out() can be safely used, until it will be only called
+ * in the reader thread.
+ * For multiple writer and one reader there is only a need to lock the writer.
+ * And vice versa for only one writer and multiple reader there is only a need
+ * to lock the reader.
+ */
+
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/stddef.h>
+#include <linux/scatterlist.h>
+
+struct __kfifo {
+ unsigned int in;
+ unsigned int out;
+ unsigned int mask;
+ unsigned int esize;
+ void *data;
+};
+
+#define __STRUCT_KFIFO_COMMON(datatype, recsize, ptrtype) \
+ union { \
+ struct __kfifo kfifo; \
+ datatype *type; \
+ char (*rectype)[recsize]; \
+ ptrtype *ptr; \
+ const ptrtype *ptr_const; \
+ }
+
+#define __STRUCT_KFIFO(type, size, recsize, ptrtype) \
+{ \
+ __STRUCT_KFIFO_COMMON(type, recsize, ptrtype); \
+ type buf[((size < 2) || (size & (size - 1))) ? -1 : size]; \
+}
+
+#define STRUCT_KFIFO(type, size) \
+ struct __STRUCT_KFIFO(type, size, 0, type)
+
+#define __STRUCT_KFIFO_PTR(type, recsize, ptrtype) \
+{ \
+ __STRUCT_KFIFO_COMMON(type, recsize, ptrtype); \
+ type buf[0]; \
+}
+
+#define STRUCT_KFIFO_PTR(type) \
+ struct __STRUCT_KFIFO_PTR(type, 0, type)
+
+/*
+ * define compatibility "struct kfifo" for dynamic allocated fifos
+ */
+struct kfifo __STRUCT_KFIFO_PTR(unsigned char, 0, void);
+
+#define STRUCT_KFIFO_REC_1(size) \
+ struct __STRUCT_KFIFO(unsigned char, size, 1, void)
+
+#define STRUCT_KFIFO_REC_2(size) \
+ struct __STRUCT_KFIFO(unsigned char, size, 2, void)
+
+/*
+ * define kfifo_rec types
+ */
+struct kfifo_rec_ptr_1 __STRUCT_KFIFO_PTR(unsigned char, 1, void);
+struct kfifo_rec_ptr_2 __STRUCT_KFIFO_PTR(unsigned char, 2, void);
+
+/*
+ * helper macro to distinguish between real in place fifo where the fifo
+ * array is a part of the structure and the fifo type where the array is
+ * outside of the fifo structure.
+ */
+#define __is_kfifo_ptr(fifo) (sizeof(*fifo) == sizeof(struct __kfifo))
+
+/**
+ * DECLARE_KFIFO_PTR - macro to declare a fifo pointer object
+ * @fifo: name of the declared fifo
+ * @type: type of the fifo elements
+ */
+#define DECLARE_KFIFO_PTR(fifo, type) STRUCT_KFIFO_PTR(type) fifo
+
+/**
+ * DECLARE_KFIFO - macro to declare a fifo object
+ * @fifo: name of the declared fifo
+ * @type: type of the fifo elements
+ * @size: the number of elements in the fifo, this must be a power of 2
+ */
+#define DECLARE_KFIFO(fifo, type, size) STRUCT_KFIFO(type, size) fifo
+
+/**
+ * INIT_KFIFO - Initialize a fifo declared by DECLARE_KFIFO
+ * @fifo: name of the declared fifo datatype
+ */
+#define INIT_KFIFO(fifo) \
+(void)({ \
+ typeof(&(fifo)) __tmp = &(fifo); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ __kfifo->in = 0; \
+ __kfifo->out = 0; \
+ __kfifo->mask = __is_kfifo_ptr(__tmp) ? 0 : ARRAY_SIZE(__tmp->buf) - 1;\
+ __kfifo->esize = sizeof(*__tmp->buf); \
+ __kfifo->data = __is_kfifo_ptr(__tmp) ? NULL : __tmp->buf; \
+})
+
+/**
+ * DEFINE_KFIFO - macro to define and initialize a fifo
+ * @fifo: name of the declared fifo datatype
+ * @type: type of the fifo elements
+ * @size: the number of elements in the fifo, this must be a power of 2
+ *
+ * Note: the macro can be used for global and local fifo data type variables.
+ */
+#define DEFINE_KFIFO(fifo, type, size) \
+ DECLARE_KFIFO(fifo, type, size) = \
+ (typeof(fifo)) { \
+ { \
+ { \
+ .in = 0, \
+ .out = 0, \
+ .mask = __is_kfifo_ptr(&(fifo)) ? \
+ 0 : \
+ ARRAY_SIZE((fifo).buf) - 1, \
+ .esize = sizeof(*(fifo).buf), \
+ .data = __is_kfifo_ptr(&(fifo)) ? \
+ NULL : \
+ (fifo).buf, \
+ } \
+ } \
+ }
+
+
+static inline unsigned int __must_check
+__kfifo_must_check_helper(unsigned int val)
+{
+ return val;
+}
+
+/**
+ * kfifo_initialized - Check if the fifo is initialized
+ * @fifo: address of the fifo to check
+ *
+ * Return %true if fifo is initialized, otherwise %false.
+ * Assumes the fifo was 0 before.
+ */
+#define kfifo_initialized(fifo) ((fifo)->kfifo.mask)
+
+/**
+ * kfifo_esize - returns the size of the element managed by the fifo
+ * @fifo: address of the fifo to be used
+ */
+#define kfifo_esize(fifo) ((fifo)->kfifo.esize)
+
+/**
+ * kfifo_recsize - returns the size of the record length field
+ * @fifo: address of the fifo to be used
+ */
+#define kfifo_recsize(fifo) (sizeof(*(fifo)->rectype))
+
+/**
+ * kfifo_size - returns the size of the fifo in elements
+ * @fifo: address of the fifo to be used
+ */
+#define kfifo_size(fifo) ((fifo)->kfifo.mask + 1)
+
+/**
+ * kfifo_reset - removes the entire fifo content
+ * @fifo: address of the fifo to be used
+ *
+ * Note: usage of kfifo_reset() is dangerous. It should be only called when the
+ * fifo is exclusived locked or when it is secured that no other thread is
+ * accessing the fifo.
+ */
+#define kfifo_reset(fifo) \
+(void)({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ __tmp->kfifo.in = __tmp->kfifo.out = 0; \
+})
+
+/**
+ * kfifo_reset_out - skip fifo content
+ * @fifo: address of the fifo to be used
+ *
+ * Note: The usage of kfifo_reset_out() is safe until it will be only called
+ * from the reader thread and there is only one concurrent reader. Otherwise
+ * it is dangerous and must be handled in the same way as kfifo_reset().
+ */
+#define kfifo_reset_out(fifo) \
+(void)({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ __tmp->kfifo.out = __tmp->kfifo.in; \
+})
+
+/**
+ * kfifo_len - returns the number of used elements in the fifo
+ * @fifo: address of the fifo to be used
+ */
+#define kfifo_len(fifo) \
+({ \
+ typeof(fifo + 1) __tmpl = (fifo); \
+ __tmpl->kfifo.in - __tmpl->kfifo.out; \
+})
+
+/**
+ * kfifo_is_empty - returns true if the fifo is empty
+ * @fifo: address of the fifo to be used
+ */
+#define kfifo_is_empty(fifo) \
+({ \
+ typeof(fifo + 1) __tmpq = (fifo); \
+ __tmpq->kfifo.in == __tmpq->kfifo.out; \
+})
+
+/**
+ * kfifo_is_full - returns true if the fifo is full
+ * @fifo: address of the fifo to be used
+ */
+#define kfifo_is_full(fifo) \
+({ \
+ typeof(fifo + 1) __tmpq = (fifo); \
+ kfifo_len(__tmpq) > __tmpq->kfifo.mask; \
+})
+
+/**
+ * kfifo_avail - returns the number of unused elements in the fifo
+ * @fifo: address of the fifo to be used
+ */
+#define kfifo_avail(fifo) \
+__kfifo_must_check_helper( \
+({ \
+ typeof(fifo + 1) __tmpq = (fifo); \
+ const size_t __recsize = sizeof(*__tmpq->rectype); \
+ unsigned int __avail = kfifo_size(__tmpq) - kfifo_len(__tmpq); \
+ (__recsize) ? ((__avail <= __recsize) ? 0 : \
+ __kfifo_max_r(__avail - __recsize, __recsize)) : \
+ __avail; \
+}) \
+)
+
+/**
+ * kfifo_skip - skip output data
+ * @fifo: address of the fifo to be used
+ */
+#define kfifo_skip(fifo) \
+(void)({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ const size_t __recsize = sizeof(*__tmp->rectype); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ if (__recsize) \
+ __kfifo_skip_r(__kfifo, __recsize); \
+ else \
+ __kfifo->out++; \
+})
+
+/**
+ * kfifo_peek_len - gets the size of the next fifo record
+ * @fifo: address of the fifo to be used
+ *
+ * This function returns the size of the next fifo record in number of bytes.
+ */
+#define kfifo_peek_len(fifo) \
+__kfifo_must_check_helper( \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ const size_t __recsize = sizeof(*__tmp->rectype); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ (!__recsize) ? kfifo_len(__tmp) * sizeof(*__tmp->type) : \
+ __kfifo_len_r(__kfifo, __recsize); \
+}) \
+)
+
+/**
+ * kfifo_alloc - dynamically allocates a new fifo buffer
+ * @fifo: pointer to the fifo
+ * @size: the number of elements in the fifo, this must be a power of 2
+ * @gfp_mask: get_free_pages mask, passed to kmalloc()
+ *
+ * This macro dynamically allocates a new fifo buffer.
+ *
+ * The numer of elements will be rounded-up to a power of 2.
+ * The fifo will be release with kfifo_free().
+ * Return 0 if no error, otherwise an error code.
+ */
+#define kfifo_alloc(fifo, size, gfp_mask) \
+__kfifo_must_check_helper( \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ __is_kfifo_ptr(__tmp) ? \
+ __kfifo_alloc(__kfifo, size, sizeof(*__tmp->type), gfp_mask) : \
+ -EINVAL; \
+}) \
+)
+
+/**
+ * kfifo_free - frees the fifo
+ * @fifo: the fifo to be freed
+ */
+#define kfifo_free(fifo) \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ if (__is_kfifo_ptr(__tmp)) \
+ __kfifo_free(__kfifo); \
+})
+
+/**
+ * kfifo_init - initialize a fifo using a preallocated buffer
+ * @fifo: the fifo to assign the buffer
+ * @buffer: the preallocated buffer to be used
+ * @size: the size of the internal buffer, this have to be a power of 2
+ *
+ * This macro initialize a fifo using a preallocated buffer.
+ *
+ * The numer of elements will be rounded-up to a power of 2.
+ * Return 0 if no error, otherwise an error code.
+ */
+#define kfifo_init(fifo, buffer, size) \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ __is_kfifo_ptr(__tmp) ? \
+ __kfifo_init(__kfifo, buffer, size, sizeof(*__tmp->type)) : \
+ -EINVAL; \
+})
+
+/**
+ * kfifo_put - put data into the fifo
+ * @fifo: address of the fifo to be used
+ * @val: the data to be added
+ *
+ * This macro copies the given value into the fifo.
+ * It returns 0 if the fifo was full. Otherwise it returns the number
+ * processed elements.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these macro.
+ */
+#define kfifo_put(fifo, val) \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ typeof(val + 1) __val = (val); \
+ unsigned int __ret; \
+ const size_t __recsize = sizeof(*__tmp->rectype); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ if (0) { \
+ typeof(__tmp->ptr_const) __dummy __attribute__ ((unused)); \
+ __dummy = (typeof(__val))NULL; \
+ } \
+ if (__recsize) \
+ __ret = __kfifo_in_r(__kfifo, __val, sizeof(*__val), \
+ __recsize); \
+ else { \
+ __ret = !kfifo_is_full(__tmp); \
+ if (__ret) { \
+ (__is_kfifo_ptr(__tmp) ? \
+ ((typeof(__tmp->type))__kfifo->data) : \
+ (__tmp->buf) \
+ )[__kfifo->in & __tmp->kfifo.mask] = \
+ *(typeof(__tmp->type))__val; \
+ smp_wmb(); \
+ __kfifo->in++; \
+ } \
+ } \
+ __ret; \
+})
+
+/**
+ * kfifo_get - get data from the fifo
+ * @fifo: address of the fifo to be used
+ * @val: the var where to store the data to be added
+ *
+ * This macro reads the data from the fifo.
+ * It returns 0 if the fifo was empty. Otherwise it returns the number
+ * processed elements.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these macro.
+ */
+#define kfifo_get(fifo, val) \
+__kfifo_must_check_helper( \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ typeof(val + 1) __val = (val); \
+ unsigned int __ret; \
+ const size_t __recsize = sizeof(*__tmp->rectype); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ if (0) \
+ __val = (typeof(__tmp->ptr))0; \
+ if (__recsize) \
+ __ret = __kfifo_out_r(__kfifo, __val, sizeof(*__val), \
+ __recsize); \
+ else { \
+ __ret = !kfifo_is_empty(__tmp); \
+ if (__ret) { \
+ *(typeof(__tmp->type))__val = \
+ (__is_kfifo_ptr(__tmp) ? \
+ ((typeof(__tmp->type))__kfifo->data) : \
+ (__tmp->buf) \
+ )[__kfifo->out & __tmp->kfifo.mask]; \
+ smp_wmb(); \
+ __kfifo->out++; \
+ } \
+ } \
+ __ret; \
+}) \
+)
+
+/**
+ * kfifo_peek - get data from the fifo without removing
+ * @fifo: address of the fifo to be used
+ * @val: the var where to store the data to be added
+ *
+ * This reads the data from the fifo without removing it from the fifo.
+ * It returns 0 if the fifo was empty. Otherwise it returns the number
+ * processed elements.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these macro.
+ */
+#define kfifo_peek(fifo, val) \
+__kfifo_must_check_helper( \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ typeof(val + 1) __val = (val); \
+ unsigned int __ret; \
+ const size_t __recsize = sizeof(*__tmp->rectype); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ if (0) \
+ __val = (typeof(__tmp->ptr))NULL; \
+ if (__recsize) \
+ __ret = __kfifo_out_peek_r(__kfifo, __val, sizeof(*__val), \
+ __recsize); \
+ else { \
+ __ret = !kfifo_is_empty(__tmp); \
+ if (__ret) { \
+ *(typeof(__tmp->type))__val = \
+ (__is_kfifo_ptr(__tmp) ? \
+ ((typeof(__tmp->type))__kfifo->data) : \
+ (__tmp->buf) \
+ )[__kfifo->out & __tmp->kfifo.mask]; \
+ smp_wmb(); \
+ } \
+ } \
+ __ret; \
+}) \
+)
+
+/**
+ * kfifo_in - put data into the fifo
+ * @fifo: address of the fifo to be used
+ * @buf: the data to be added
+ * @n: number of elements to be added
+ *
+ * This macro copies the given buffer into the fifo and returns the
+ * number of copied elements.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these macro.
+ */
+#define kfifo_in(fifo, buf, n) \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ typeof(buf + 1) __buf = (buf); \
+ unsigned long __n = (n); \
+ const size_t __recsize = sizeof(*__tmp->rectype); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ if (0) { \
+ typeof(__tmp->ptr_const) __dummy __attribute__ ((unused)); \
+ __dummy = (typeof(__buf))NULL; \
+ } \
+ (__recsize) ?\
+ __kfifo_in_r(__kfifo, __buf, __n, __recsize) : \
+ __kfifo_in(__kfifo, __buf, __n); \
+})
+
+/**
+ * kfifo_in_spinlocked - put data into the fifo using a spinlock for locking
+ * @fifo: address of the fifo to be used
+ * @buf: the data to be added
+ * @n: number of elements to be added
+ * @lock: pointer to the spinlock to use for locking
+ *
+ * This macro copies the given values buffer into the fifo and returns the
+ * number of copied elements.
+ */
+#define kfifo_in_spinlocked(fifo, buf, n, lock) \
+({ \
+ unsigned long __flags; \
+ unsigned int __ret; \
+ spin_lock_irqsave(lock, __flags); \
+ __ret = kfifo_in(fifo, buf, n); \
+ spin_unlock_irqrestore(lock, __flags); \
+ __ret; \
+})
+
+/* alias for kfifo_in_spinlocked, will be removed in a future release */
+#define kfifo_in_locked(fifo, buf, n, lock) \
+ kfifo_in_spinlocked(fifo, buf, n, lock)
+
+/**
+ * kfifo_out - get data from the fifo
+ * @fifo: address of the fifo to be used
+ * @buf: pointer to the storage buffer
+ * @n: max. number of elements to get
+ *
+ * This macro get some data from the fifo and return the numbers of elements
+ * copied.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these macro.
+ */
+#define kfifo_out(fifo, buf, n) \
+__kfifo_must_check_helper( \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ typeof(buf + 1) __buf = (buf); \
+ unsigned long __n = (n); \
+ const size_t __recsize = sizeof(*__tmp->rectype); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ if (0) { \
+ typeof(__tmp->ptr) __dummy = NULL; \
+ __buf = __dummy; \
+ } \
+ (__recsize) ?\
+ __kfifo_out_r(__kfifo, __buf, __n, __recsize) : \
+ __kfifo_out(__kfifo, __buf, __n); \
+}) \
+)
+
+/**
+ * kfifo_out_spinlocked - get data from the fifo using a spinlock for locking
+ * @fifo: address of the fifo to be used
+ * @buf: pointer to the storage buffer
+ * @n: max. number of elements to get
+ * @lock: pointer to the spinlock to use for locking
+ *
+ * This macro get the data from the fifo and return the numbers of elements
+ * copied.
+ */
+#define kfifo_out_spinlocked(fifo, buf, n, lock) \
+__kfifo_must_check_helper( \
+({ \
+ unsigned long __flags; \
+ unsigned int __ret; \
+ spin_lock_irqsave(lock, __flags); \
+ __ret = kfifo_out(fifo, buf, n); \
+ spin_unlock_irqrestore(lock, __flags); \
+ __ret; \
+}) \
+)
+
+/* alias for kfifo_out_spinlocked, will be removed in a future release */
+#define kfifo_out_locked(fifo, buf, n, lock) \
+ kfifo_out_spinlocked(fifo, buf, n, lock)
+
+/**
+ * kfifo_from_user - puts some data from user space into the fifo
+ * @fifo: address of the fifo to be used
+ * @from: pointer to the data to be added
+ * @len: the length of the data to be added
+ * @copied: pointer to output variable to store the number of copied bytes
+ *
+ * This macro copies at most @len bytes from the @from into the
+ * fifo, depending of the available space and returns -EFAULT/0.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these macro.
+ */
+#define kfifo_from_user(fifo, from, len, copied) \
+__kfifo_must_check_helper( \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ const void __user *__from = (from); \
+ unsigned int __len = (len); \
+ unsigned int *__copied = (copied); \
+ const size_t __recsize = sizeof(*__tmp->rectype); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ (__recsize) ? \
+ __kfifo_from_user_r(__kfifo, __from, __len, __copied, __recsize) : \
+ __kfifo_from_user(__kfifo, __from, __len, __copied); \
+}) \
+)
+
+/**
+ * kfifo_to_user - copies data from the fifo into user space
+ * @fifo: address of the fifo to be used
+ * @to: where the data must be copied
+ * @len: the size of the destination buffer
+ * @copied: pointer to output variable to store the number of copied bytes
+ *
+ * This macro copies at most @len bytes from the fifo into the
+ * @to buffer and returns -EFAULT/0.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these macro.
+ */
+#define kfifo_to_user(fifo, to, len, copied) \
+__kfifo_must_check_helper( \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ void __user *__to = (to); \
+ unsigned int __len = (len); \
+ unsigned int *__copied = (copied); \
+ const size_t __recsize = sizeof(*__tmp->rectype); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ (__recsize) ? \
+ __kfifo_to_user_r(__kfifo, __to, __len, __copied, __recsize) : \
+ __kfifo_to_user(__kfifo, __to, __len, __copied); \
+}) \
+)
+
+/**
+ * kfifo_dma_in_prepare - setup a scatterlist for DMA input
+ * @fifo: address of the fifo to be used
+ * @sgl: pointer to the scatterlist array
+ * @nents: number of entries in the scatterlist array
+ * @len: number of elements to transfer
+ *
+ * This macro fills a scatterlist for DMA input.
+ * It returns the number entries in the scatterlist array.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these macros.
+ */
+#define kfifo_dma_in_prepare(fifo, sgl, nents, len) \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ struct scatterlist *__sgl = (sgl); \
+ int __nents = (nents); \
+ unsigned int __len = (len); \
+ const size_t __recsize = sizeof(*__tmp->rectype); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ (__recsize) ? \
+ __kfifo_dma_in_prepare_r(__kfifo, __sgl, __nents, __len, __recsize) : \
+ __kfifo_dma_in_prepare(__kfifo, __sgl, __nents, __len); \
+})
+
+/**
+ * kfifo_dma_in_finish - finish a DMA IN operation
+ * @fifo: address of the fifo to be used
+ * @len: number of bytes to received
+ *
+ * This macro finish a DMA IN operation. The in counter will be updated by
+ * the len parameter. No error checking will be done.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these macros.
+ */
+#define kfifo_dma_in_finish(fifo, len) \
+(void)({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ unsigned int __len = (len); \
+ const size_t __recsize = sizeof(*__tmp->rectype); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ if (__recsize) \
+ __kfifo_dma_in_finish_r(__kfifo, __len, __recsize); \
+ else \
+ __kfifo->in += __len / sizeof(*__tmp->type); \
+})
+
+/**
+ * kfifo_dma_out_prepare - setup a scatterlist for DMA output
+ * @fifo: address of the fifo to be used
+ * @sgl: pointer to the scatterlist array
+ * @nents: number of entries in the scatterlist array
+ * @len: number of elements to transfer
+ *
+ * This macro fills a scatterlist for DMA output which at most @len bytes
+ * to transfer.
+ * It returns the number entries in the scatterlist array.
+ * A zero means there is no space available and the scatterlist is not filled.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these macros.
+ */
+#define kfifo_dma_out_prepare(fifo, sgl, nents, len) \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ struct scatterlist *__sgl = (sgl); \
+ int __nents = (nents); \
+ unsigned int __len = (len); \
+ const size_t __recsize = sizeof(*__tmp->rectype); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ (__recsize) ? \
+ __kfifo_dma_out_prepare_r(__kfifo, __sgl, __nents, __len, __recsize) : \
+ __kfifo_dma_out_prepare(__kfifo, __sgl, __nents, __len); \
+})
+
+/**
+ * kfifo_dma_out_finish - finish a DMA OUT operation
+ * @fifo: address of the fifo to be used
+ * @len: number of bytes transferd
+ *
+ * This macro finish a DMA OUT operation. The out counter will be updated by
+ * the len parameter. No error checking will be done.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these macros.
+ */
+#define kfifo_dma_out_finish(fifo, len) \
+(void)({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ unsigned int __len = (len); \
+ const size_t __recsize = sizeof(*__tmp->rectype); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ if (__recsize) \
+ __kfifo_dma_out_finish_r(__kfifo, __recsize); \
+ else \
+ __kfifo->out += __len / sizeof(*__tmp->type); \
+})
+
+/**
+ * kfifo_out_peek - gets some data from the fifo
+ * @fifo: address of the fifo to be used
+ * @buf: pointer to the storage buffer
+ * @n: max. number of elements to get
+ *
+ * This macro get the data from the fifo and return the numbers of elements
+ * copied. The data is not removed from the fifo.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these macro.
+ */
+#define kfifo_out_peek(fifo, buf, n) \
+__kfifo_must_check_helper( \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ typeof(buf + 1) __buf = (buf); \
+ unsigned long __n = (n); \
+ const size_t __recsize = sizeof(*__tmp->rectype); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ if (0) { \
+ typeof(__tmp->ptr) __dummy __attribute__ ((unused)) = NULL; \
+ __buf = __dummy; \
+ } \
+ (__recsize) ? \
+ __kfifo_out_peek_r(__kfifo, __buf, __n, __recsize) : \
+ __kfifo_out_peek(__kfifo, __buf, __n); \
+}) \
+)
+
+extern int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,
+ size_t esize, gfp_t gfp_mask);
+
+extern void __kfifo_free(struct __kfifo *fifo);
+
+extern int __kfifo_init(struct __kfifo *fifo, void *buffer,
+ unsigned int size, size_t esize);
+
+extern unsigned int __kfifo_in(struct __kfifo *fifo,
+ const void *buf, unsigned int len);
+
+extern unsigned int __kfifo_out(struct __kfifo *fifo,
+ void *buf, unsigned int len);
+
+extern int __kfifo_from_user(struct __kfifo *fifo,
+ const void __user *from, unsigned long len, unsigned int *copied);
+
+extern int __kfifo_to_user(struct __kfifo *fifo,
+ void __user *to, unsigned long len, unsigned int *copied);
+
+extern unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len);
+
+extern unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len);
+
+extern unsigned int __kfifo_out_peek(struct __kfifo *fifo,
+ void *buf, unsigned int len);
+
+extern unsigned int __kfifo_in_r(struct __kfifo *fifo,
+ const void *buf, unsigned int len, size_t recsize);
+
+extern unsigned int __kfifo_out_r(struct __kfifo *fifo,
+ void *buf, unsigned int len, size_t recsize);
+
+extern int __kfifo_from_user_r(struct __kfifo *fifo,
+ const void __user *from, unsigned long len, unsigned int *copied,
+ size_t recsize);
+
+extern int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to,
+ unsigned long len, unsigned int *copied, size_t recsize);
+
+extern unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len, size_t recsize);
+
+extern void __kfifo_dma_in_finish_r(struct __kfifo *fifo,
+ unsigned int len, size_t recsize);
+
+extern unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len, size_t recsize);
+
+extern void __kfifo_dma_out_finish_r(struct __kfifo *fifo, size_t recsize);
+
+extern unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize);
+
+extern unsigned int __kfifo_out_peek_r(struct __kfifo *fifo,
+ void *buf, unsigned int len, size_t recsize);
+
+extern unsigned int __kfifo_max_r(unsigned int len, size_t recsize);
+
+#endif
+
diff -u -N -r -p linux-2.6.33-rc7.dummy/kernel/kfifo.c linux-2.6.33-rc7.new/kernel/kfifo.c
--- linux-2.6.33-rc7.dummy/kernel/kfifo.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.33-rc7.new/kernel/kfifo.c 2010-02-11 17:09:04.524741109 +0100
@@ -0,0 +1,603 @@
+/*
+ * A generic kernel FIFO implementation
+ *
+ * Copyright (C) 2009/2010 Stefani Seibold <stefani@seibold.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/log2.h>
+#include <linux/uaccess.h>
+#include <linux/kfifo.h>
+
+/*
+ * internal helper to calculate the unused elements in a fifo
+ */
+static inline unsigned int kfifo_unused(struct __kfifo *fifo)
+{
+ return (fifo->mask + 1) - (fifo->in - fifo->out);
+}
+
+int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,
+ size_t esize, gfp_t gfp_mask)
+{
+ /*
+ * round down to the next power of 2, since our 'let the indices
+ * wrap' technique works only in this case.
+ */
+ if (!is_power_of_2(size))
+ size = rounddown_pow_of_two(size);
+
+ fifo->in = 0;
+ fifo->out = 0;
+ fifo->esize = esize;
+
+ if (size < 2) {
+ fifo->data = NULL;
+ fifo->mask = 0;
+ return -EINVAL;
+ }
+
+ fifo->data = kmalloc(size * esize, gfp_mask);
+
+ if (!fifo->data) {
+ fifo->mask = 0;
+ return -ENOMEM;
+ }
+ fifo->mask = size - 1;
+
+ return 0;
+}
+EXPORT_SYMBOL(__kfifo_alloc);
+
+void __kfifo_free(struct __kfifo *fifo)
+{
+ kfree(fifo->data);
+ fifo->in = 0;
+ fifo->out = 0;
+ fifo->esize = 0;
+ fifo->data = NULL;
+ fifo->mask = 0;
+}
+EXPORT_SYMBOL(__kfifo_free);
+
+int __kfifo_init(struct __kfifo *fifo, void *buffer,
+ unsigned int size, size_t esize)
+{
+ size /= esize;
+
+ if (!is_power_of_2(size))
+ size = rounddown_pow_of_two(size);
+
+ fifo->in = 0;
+ fifo->out = 0;
+ fifo->esize = esize;
+ fifo->data = buffer;
+
+ if (size < 2) {
+ fifo->mask = 0;
+ return -EINVAL;
+ }
+ fifo->mask = size - 1;
+
+ return 0;
+}
+EXPORT_SYMBOL(__kfifo_init);
+
+static void kfifo_copy_in(struct __kfifo *fifo, const void *src,
+ unsigned int len, unsigned int off)
+{
+ unsigned int size = fifo->mask + 1;
+ unsigned int esize = fifo->esize;
+ unsigned int l;
+
+ off &= fifo->mask;
+ if (esize != 1) {
+ off *= esize;
+ size *= esize;
+ len *= esize;
+ }
+ l = min(len, size - off);
+
+ memcpy(fifo->data + off, src, l);
+ memcpy(fifo->data, src + l, len - l);
+ /*
+ * make sure that the data in the fifo is up to date before
+ * incrementing the fifo->in index counter
+ */
+ smp_wmb();
+}
+
+unsigned int __kfifo_in(struct __kfifo *fifo,
+ const void *buf, unsigned int len)
+{
+ unsigned int l;
+
+ l = kfifo_unused(fifo);
+ if (len > l)
+ len = l;
+
+ kfifo_copy_in(fifo, buf, len, fifo->in);
+ fifo->in += len;
+ return len;
+}
+EXPORT_SYMBOL(__kfifo_in);
+
+static void kfifo_copy_out(struct __kfifo *fifo, void *dst,
+ unsigned int len, unsigned int off)
+{
+ unsigned int size = fifo->mask + 1;
+ unsigned int esize = fifo->esize;
+ unsigned int l;
+
+ off &= fifo->mask;
+ if (esize != 1) {
+ off *= esize;
+ size *= esize;
+ len *= esize;
+ }
+ l = min(len, size - off);
+
+ memcpy(dst, fifo->data + off, l);
+ memcpy(dst + l, fifo->data, len - l);
+ /*
+ * make sure that the data is copied before
+ * incrementing the fifo->out index counter
+ */
+ smp_wmb();
+}
+
+unsigned int __kfifo_out_peek(struct __kfifo *fifo,
+ void *buf, unsigned int len)
+{
+ unsigned int l;
+
+ l = fifo->in - fifo->out;
+ if (len > l)
+ len = l;
+
+ kfifo_copy_out(fifo, buf, len, fifo->out);
+ return len;
+}
+EXPORT_SYMBOL(__kfifo_out_peek);
+
+unsigned int __kfifo_out(struct __kfifo *fifo,
+ void *buf, unsigned int len)
+{
+ len = __kfifo_out_peek(fifo, buf, len);
+ fifo->out += len;
+ return len;
+}
+EXPORT_SYMBOL(__kfifo_out);
+
+static unsigned long kfifo_copy_from_user(struct __kfifo *fifo,
+ const void __user *from, unsigned int len, unsigned int off,
+ unsigned int *copied)
+{
+ unsigned int size = fifo->mask + 1;
+ unsigned int esize = fifo->esize;
+ unsigned int l;
+ unsigned long ret;
+
+ off &= fifo->mask;
+ if (esize != 1) {
+ off *= esize;
+ size *= esize;
+ len *= esize;
+ }
+ l = min(len, size - off);
+
+ ret = copy_from_user(fifo->data + off, from, l);
+ if (unlikely(ret))
+ ret = DIV_ROUND_UP(ret + len - l, esize);
+ else {
+ ret = copy_from_user(fifo->data, from + l, len - l);
+ if (unlikely(ret))
+ ret = DIV_ROUND_UP(ret, esize);
+ }
+ /*
+ * make sure that the data in the fifo is up to date before
+ * incrementing the fifo->in index counter
+ */
+ smp_wmb();
+ *copied = len - ret;
+ /* return the number of elements which are not copied */
+ return ret;
+}
+
+int __kfifo_from_user(struct __kfifo *fifo, const void __user *from,
+ unsigned long len, unsigned int *copied)
+{
+ unsigned int l;
+ unsigned long ret;
+ unsigned int esize = fifo->esize;
+ int err;
+
+ if (esize != 1)
+ len /= esize;
+
+ l = kfifo_unused(fifo);
+ if (len > l)
+ len = l;
+
+ ret = kfifo_copy_from_user(fifo, from, len, fifo->in, copied);
+ if (unlikely(ret)) {
+ len -= ret;
+ err = -EFAULT;
+ } else
+ err = 0;
+ fifo->in += len;
+ return err;
+}
+EXPORT_SYMBOL(__kfifo_from_user);
+
+static unsigned long kfifo_copy_to_user(struct __kfifo *fifo, void __user *to,
+ unsigned int len, unsigned int off, unsigned int *copied)
+{
+ unsigned int l;
+ unsigned long ret;
+ unsigned int size = fifo->mask + 1;
+ unsigned int esize = fifo->esize;
+
+ off &= fifo->mask;
+ if (esize != 1) {
+ off *= esize;
+ size *= esize;
+ len *= esize;
+ }
+ l = min(len, size - off);
+
+ ret = copy_to_user(to, fifo->data + off, l);
+ if (unlikely(ret))
+ ret = DIV_ROUND_UP(ret + len - l, esize);
+ else {
+ ret = copy_to_user(to + l, fifo->data, len - l);
+ if (unlikely(ret))
+ ret = DIV_ROUND_UP(ret, esize);
+ }
+ /*
+ * make sure that the data is copied before
+ * incrementing the fifo->out index counter
+ */
+ smp_wmb();
+ *copied = len - ret;
+ /* return the number of elements which are not copied */
+ return ret;
+}
+
+int __kfifo_to_user(struct __kfifo *fifo, void __user *to,
+ unsigned long len, unsigned int *copied)
+{
+ unsigned int l;
+ unsigned long ret;
+ unsigned int esize = fifo->esize;
+ int err;
+
+ if (esize != 1)
+ len /= esize;
+
+ l = fifo->in - fifo->out;
+ if (len > l)
+ len = l;
+ ret = kfifo_copy_to_user(fifo, to, len, fifo->out, copied);
+ if (unlikely(ret)) {
+ len -= ret;
+ err = -EFAULT;
+ } else
+ err = 0;
+ fifo->out += len;
+ return err;
+}
+EXPORT_SYMBOL(__kfifo_to_user);
+
+static int setup_sgl_buf(struct scatterlist *sgl, void *buf,
+ int nents, unsigned int len)
+{
+ int n;
+ unsigned int l;
+ unsigned int off;
+ struct page *page;
+
+ if (!nents)
+ return 0;
+
+ if (!len)
+ return 0;
+
+ n = 0;
+ page = virt_to_page(buf);
+ off = offset_in_page(buf);
+ l = 0;
+
+ while (len >= l + PAGE_SIZE - off) {
+ struct page *npage;
+
+ l += PAGE_SIZE;
+ buf += PAGE_SIZE;
+ npage = virt_to_page(buf);
+ if (page_to_phys(page) != page_to_phys(npage) - l) {
+ sgl->page_link = 0;
+ sg_set_page(sgl++, page, l - off, off);
+ if (++n == nents)
+ return n;
+ page = npage;
+ len -= l - off;
+ l = off = 0;
+ }
+ }
+ sgl->page_link = 0;
+ sg_set_page(sgl++, page, len, off);
+ return n + 1;
+}
+
+static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl,
+ int nents, unsigned int len, unsigned int off)
+{
+ unsigned int size = fifo->mask + 1;
+ unsigned int esize = fifo->esize;
+ unsigned int l;
+ unsigned int n;
+
+ off &= fifo->mask;
+ if (esize != 1) {
+ off *= esize;
+ size *= esize;
+ len *= esize;
+ }
+ l = min(len, size - off);
+
+ n = setup_sgl_buf(sgl, fifo->data + off, nents, l);
+ n += setup_sgl_buf(sgl + n, fifo->data, nents - n, len - l);
+
+ if (n)
+ sg_mark_end(sgl + n - 1);
+ return n;
+}
+
+unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len)
+{
+ unsigned int l;
+
+ l = kfifo_unused(fifo);
+ if (len > l)
+ len = l;
+
+ return setup_sgl(fifo, sgl, nents, len, fifo->in);
+}
+EXPORT_SYMBOL(__kfifo_dma_in_prepare);
+
+unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len)
+{
+ unsigned int l;
+
+ l = fifo->in - fifo->out;
+ if (len > l)
+ len = l;
+
+ return setup_sgl(fifo, sgl, nents, len, fifo->out);
+}
+EXPORT_SYMBOL(__kfifo_dma_out_prepare);
+
+unsigned int __kfifo_max_r(unsigned int len, size_t recsize)
+{
+ unsigned int max = (1 << (recsize << 3)) - 1;
+
+ if (len > max)
+ return max;
+ return len;
+}
+
+#define __KFIFO_PEEK(data, out, mask) \
+ ((data)[(out) & (mask)])
+/*
+ * __kfifo_peek_n internal helper function for determinate the length of
+ * the next record in the fifo
+ */
+static unsigned int __kfifo_peek_n(struct __kfifo *fifo, size_t recsize)
+{
+ unsigned int l;
+ unsigned int mask = fifo->mask;
+ unsigned char *data = fifo->data;
+
+ l = __KFIFO_PEEK(data, fifo->out, mask);
+
+ if (--recsize)
+ l |= __KFIFO_PEEK(data, fifo->out + 1, mask) << 8;
+
+ return l;
+}
+
+#define __KFIFO_POKE(data, in, mask, val) \
+ ( \
+ (data)[(in) & (mask)] = (unsigned char)(val) \
+ )
+
+/*
+ * __kfifo_poke_n internal helper function for storeing the length of
+ * the record into the fifo
+ */
+static void __kfifo_poke_n(struct __kfifo *fifo, unsigned int n, size_t recsize)
+{
+ unsigned int mask = fifo->mask;
+ unsigned char *data = fifo->data;
+
+ __KFIFO_POKE(data, fifo->in, mask, n);
+
+ if (recsize > 1)
+ __KFIFO_POKE(data, fifo->in + 1, mask, n >> 8);
+}
+
+unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize)
+{
+ return __kfifo_peek_n(fifo, recsize);
+}
+EXPORT_SYMBOL(__kfifo_len_r);
+
+unsigned int __kfifo_in_r(struct __kfifo *fifo, const void *buf,
+ unsigned int len, size_t recsize)
+{
+ if (len + recsize > kfifo_unused(fifo))
+ return 0;
+
+ __kfifo_poke_n(fifo, len, recsize);
+
+ kfifo_copy_in(fifo, buf, len, fifo->in + recsize);
+ fifo->in += len + recsize;
+ return len;
+}
+EXPORT_SYMBOL(__kfifo_in_r);
+
+static unsigned int kfifo_out_copy_r(struct __kfifo *fifo,
+ void *buf, unsigned int len, size_t recsize, unsigned int *n)
+{
+ *n = __kfifo_peek_n(fifo, recsize);
+
+ if (len > *n)
+ len = *n;
+
+ kfifo_copy_out(fifo, buf, len, fifo->out + recsize);
+ return len;
+}
+
+unsigned int __kfifo_out_peek_r(struct __kfifo *fifo, void *buf,
+ unsigned int len, size_t recsize)
+{
+ unsigned int n;
+
+ if (fifo->in == fifo->out)
+ return 0;
+
+ return kfifo_out_copy_r(fifo, buf, len, recsize, &n);
+}
+EXPORT_SYMBOL(__kfifo_out_peek_r);
+
+unsigned int __kfifo_out_r(struct __kfifo *fifo, void *buf,
+ unsigned int len, size_t recsize)
+{
+ unsigned int n;
+
+ if (fifo->in == fifo->out)
+ return 0;
+
+ len = kfifo_out_copy_r(fifo, buf, len, recsize, &n);
+ fifo->out += n + recsize;
+ return len;
+}
+EXPORT_SYMBOL(__kfifo_out_r);
+
+int __kfifo_from_user_r(struct __kfifo *fifo, const void __user *from,
+ unsigned long len, unsigned int *copied, size_t recsize)
+{
+ unsigned long ret;
+
+ len = __kfifo_max_r(len, recsize);
+
+ if (len + recsize > kfifo_unused(fifo)) {
+ *copied = 0;
+ return 0;
+ }
+
+ __kfifo_poke_n(fifo, len, recsize);
+
+ ret = kfifo_copy_from_user(fifo, from, len, fifo->in + recsize, copied);
+ if (unlikely(ret)) {
+ *copied = 0;
+ return -EFAULT;
+ }
+ fifo->in += len + recsize;
+ return 0;
+}
+EXPORT_SYMBOL(__kfifo_from_user_r);
+
+int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to,
+ unsigned long len, unsigned int *copied, size_t recsize)
+{
+ unsigned long ret;
+ unsigned int n;
+
+ if (fifo->in == fifo->out) {
+ *copied = 0;
+ return 0;
+ }
+
+ n = __kfifo_peek_n(fifo, recsize);
+ if (len > n)
+ len = n;
+
+ ret = kfifo_copy_to_user(fifo, to, len, fifo->out + recsize, copied);
+ if (unlikely(ret)) {
+ *copied = 0;
+ return -EFAULT;
+ }
+ fifo->out += n + recsize;
+ return 0;
+}
+EXPORT_SYMBOL(__kfifo_to_user_r);
+
+unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)
+{
+ if (!nents)
+ BUG();
+
+ len = __kfifo_max_r(len, recsize);
+
+ if (len + recsize > kfifo_unused(fifo))
+ return 0;
+
+ return setup_sgl(fifo, sgl, nents, len, fifo->in + recsize);
+}
+EXPORT_SYMBOL(__kfifo_dma_in_prepare_r);
+
+void __kfifo_dma_in_finish_r(struct __kfifo *fifo,
+ unsigned int len, size_t recsize)
+{
+ len = __kfifo_max_r(len, recsize);
+ __kfifo_poke_n(fifo, len, recsize);
+ fifo->in += len + recsize;
+}
+EXPORT_SYMBOL(__kfifo_dma_in_finish_r);
+
+unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)
+{
+ if (!nents)
+ BUG();
+
+ len = __kfifo_max_r(len, recsize);
+
+ if (len + recsize > fifo->in - fifo->out)
+ return 0;
+
+ return setup_sgl(fifo, sgl, nents, len, fifo->out + recsize);
+}
+EXPORT_SYMBOL(__kfifo_dma_out_prepare_r);
+
+void __kfifo_dma_out_finish_r(struct __kfifo *fifo, size_t recsize)
+{
+ unsigned int len;
+
+ len = __kfifo_peek_n(fifo, recsize);
+ fifo->out += len + recsize;
+}
+EXPORT_SYMBOL(__kfifo_dma_out_finish_r);
+
^ permalink raw reply [flat|nested] 13+ messages in thread* Re: [PATCH 4/4] add example files to the kernel sample directory
2010-02-12 7:52 [PATCH 0/4] enhanced reimplemention of the kfifo API Stefani Seibold
` (2 preceding siblings ...)
2010-02-12 8:03 ` [PATCH 3/4] add the new generic kfifo API Stefani Seibold
@ 2010-02-12 8:07 ` Stefani Seibold
2010-02-19 9:39 ` Enhanced reimplemention of the kfifo API request for merge Stefani Seibold
4 siblings, 0 replies; 13+ messages in thread
From: Stefani Seibold @ 2010-02-12 8:07 UTC (permalink / raw)
To: linux-kernel
Cc: Andrew Morton, Andi Kleen, Greg Kroah-Hartman, Alan Cox,
Theodore Tso, Ira W. Snyder
This patch add four examples to the kernel sample directory.
It shows how to handle:
- a byte stream fifo
- a integer type fifo
- a dynamic record sized fifo
- the fifo DMA functions
Signed-off-by: Stefani Seibold <stefani@seibold.net>
---
Kconfig | 10 ++
Makefile | 2
kfifo/Makefile | 1
kfifo/bytestream-example.c | 163 +++++++++++++++++++++++++++++++++++++++++++
kfifo/dma-example.c | 115 ++++++++++++++++++++++++++++++
kfifo/inttype-example.c | 157 ++++++++++++++++++++++++++++++++++++++++++
kfifo/record-example.c | 167 +++++++++++++++++++++++++++++++++++++++++++++
7 files changed, 614 insertions(+), 1 deletion(-)
diff -u -N -r -p linux-2.6.33-rc7.orig/samples/Kconfig linux-2.6.33-rc7.new/samples/Kconfig
--- linux-2.6.33-rc7.orig/samples/Kconfig 2010-02-11 17:05:58.178434640 +0100
+++ linux-2.6.33-rc7.new/samples/Kconfig 2010-02-12 08:31:54.092732092 +0100
@@ -44,4 +44,14 @@ config SAMPLE_HW_BREAKPOINT
help
This builds kernel hardware breakpoint example modules.
+config SAMPLE_KFIFO
+ tristate "Build kfifo examples -- loadable modules only"
+ depends on m
+ help
+ This config option will allow you to build a number of
+ different kfifo sample modules showing how to use the
+ generic kfifo API.
+
+ If in doubt, say "N" here.
+
endif # SAMPLES
diff -u -N -r -p linux-2.6.33-rc7.orig/samples/kfifo/bytestream-example.c linux-2.6.33-rc7.new/samples/kfifo/bytestream-example.c
--- linux-2.6.33-rc7.orig/samples/kfifo/bytestream-example.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.33-rc7.new/samples/kfifo/bytestream-example.c 2010-02-12 08:32:18.250874734 +0100
@@ -0,0 +1,163 @@
+/*
+ * Sample kfifo byte stream implementation
+ *
+ * Copyright (C) 2010 Stefani Seibold <stefani@seibold.net>
+ *
+ * Released under the GPL version 2 only.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/mutex.h>
+#include <linux/kfifo.h>
+
+/*
+ * This module shows how to create a byte stream fifo.
+ */
+
+/* fifo size in elements (bytes) */
+#define FIFO_SIZE 32
+
+/* name of the proc entry */
+#define PROC_FIFO "bytestream-fifo"
+
+/* lock for procfs read access */
+static DEFINE_MUTEX(read_lock);
+
+/* lock for procfs write access */
+static DEFINE_MUTEX(write_lock);
+
+/*
+ * define DYNAMIC in this example for a dynamically allocated fifo.
+ *
+ * Otherwise the fifo storage will be a part of the fifo structure.
+ */
+#if 0
+#define DYNAMIC
+#endif
+
+#ifdef DYNAMIC
+static struct kfifo test;
+#else
+static DECLARE_KFIFO(test, unsigned char, FIFO_SIZE);
+#endif
+
+static int __init testfunc(void)
+{
+ unsigned char buf[6];
+ unsigned char i;
+ unsigned int ret;
+
+ printk(KERN_INFO "byte stream fifo test start\n");
+
+ /* put string into the fifo */
+ kfifo_in(&test, "hello", 5);
+
+ /* put values into the fifo */
+ for (i = 0; i != 10; i++)
+ kfifo_put(&test, &i);
+
+ /* show the number of used elements */
+ printk(KERN_INFO "fifo len: %u\n", kfifo_len(&test));
+
+ /* get max of 5 bytes from the fifo */
+ i = kfifo_out(&test, buf, 5);
+ printk(KERN_INFO "buf: %.*s\n", i, buf);
+
+ /* get max of 2 elements from the fifo */
+ ret = kfifo_out(&test, buf, 2);
+ printk(KERN_INFO "ret: %d\n", ret);
+ /* and put it back to the end of the fifo */
+ ret = kfifo_in(&test, buf, ret);
+ printk(KERN_INFO "ret: %d\n", ret);
+
+ /* put values into the fifo until is full */
+ for (i = 20; kfifo_put(&test, &i); i++)
+ ;
+
+ printk(KERN_INFO "queue len: %u\n", kfifo_len(&test));
+
+ /* print out all values in the fifo */
+ while (kfifo_get(&test, &i))
+ printk("%d ", i);
+ printk("\n");
+
+ return 0;
+}
+
+static ssize_t fifo_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int ret;
+ unsigned int copied;
+
+ if (mutex_lock_interruptible(&write_lock))
+ return -ERESTARTSYS;
+
+ ret = kfifo_from_user(&test, buf, count, &copied);
+
+ mutex_unlock(&write_lock);
+
+ return ret ? ret : copied;
+}
+
+static ssize_t fifo_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int ret;
+ unsigned int copied;
+
+ if (mutex_lock_interruptible(&read_lock))
+ return -ERESTARTSYS;
+
+ ret = kfifo_to_user(&test, buf, count, &copied);
+
+ mutex_unlock(&read_lock);
+
+ return ret ? ret : copied;
+}
+
+static const struct file_operations fifo_fops = {
+ .owner = THIS_MODULE,
+ .read = fifo_read,
+ .write = fifo_write,
+};
+
+static int __init example_init(void)
+{
+#ifdef DYNAMIC
+ int ret;
+
+ ret = kfifo_alloc(&test, FIFO_SIZE, GFP_KERNEL);
+ if (ret) {
+ printk(KERN_ERR "error kfifo_alloc\n");
+ return ret;
+ }
+#else
+ INIT_KFIFO(test);
+#endif
+ testfunc();
+
+ if (proc_create(PROC_FIFO, 0, NULL, &fifo_fops) == NULL) {
+#ifdef DYNAMIC
+ kfifo_free(&test);
+#endif
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+static void __exit example_exit(void)
+{
+ remove_proc_entry(PROC_FIFO, NULL);
+#ifdef DYNAMIC
+ kfifo_free(&test);
+#endif
+}
+
+module_init(example_init);
+module_exit(example_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Stefani Seibold <stefani@seibold.net>");
Dateien linux-2.6.33-rc7.orig/samples/kfifo/.bytestream-example.c.swp und linux-2.6.33-rc7.new/samples/kfifo/.bytestream-example.c.swp sind verschieden.
diff -u -N -r -p linux-2.6.33-rc7.orig/samples/kfifo/dma-example.c linux-2.6.33-rc7.new/samples/kfifo/dma-example.c
--- linux-2.6.33-rc7.orig/samples/kfifo/dma-example.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.33-rc7.new/samples/kfifo/dma-example.c 2010-02-12 08:32:18.252420182 +0100
@@ -0,0 +1,115 @@
+/*
+ * Sample fifo dma implementation
+ *
+ * Copyright (C) 2010 Stefani Seibold <stefani@seibold.net>
+ *
+ * Released under the GPL version 2 only.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kfifo.h>
+
+/*
+ * This module shows how to handle fifo dma operations.
+ */
+
+/* fifo size in elements (bytes) */
+#define FIFO_SIZE 32
+
+static struct kfifo fifo;
+
+static int __init example_init(void)
+{
+ int i;
+ unsigned int ret;
+ struct scatterlist sg[10];
+
+ printk(KERN_INFO "DMA fifo test start\n");
+
+ if (kfifo_alloc(&fifo, FIFO_SIZE, GFP_KERNEL)) {
+ printk(KERN_ERR "error kfifo_alloc\n");
+ return 1;
+ }
+
+ printk(KERN_INFO "queue size: %u\n", kfifo_size(&fifo));
+
+ kfifo_in(&fifo, "test", 4);
+
+ for (i = 0; i != 9; i++)
+ kfifo_put(&fifo, &i);
+
+ /* kick away first byte */
+ ret = kfifo_get(&fifo, &i);
+
+ printk(KERN_INFO "queue len: %u\n", kfifo_len(&fifo));
+
+ ret = kfifo_dma_in_prepare(&fifo, sg, ARRAY_SIZE(sg), FIFO_SIZE);
+ printk(KERN_INFO "DMA sgl entries: %d\n", ret);
+
+ /* if 0 was returned, fifo is full and no sgl was created */
+ if (ret) {
+ printk(KERN_INFO "scatterlist for receive:\n");
+ for (i = 0; i < ARRAY_SIZE(sg); i++) {
+ printk(KERN_INFO
+ "sg[%d] -> "
+ "page_link 0x%.8lx offset 0x%.8x length 0x%.8x\n",
+ i, sg[i].page_link, sg[i].offset, sg[i].length);
+
+ if (sg_is_last(&sg[i]))
+ break;
+ }
+
+ /* but here your code to setup and exectute the dma operation */
+ /* ... */
+
+ /* example: zero bytes received */
+ ret = 0;
+
+ /* finish the dma operation and update the received data */
+ kfifo_dma_in_finish(&fifo, ret);
+ }
+
+ ret = kfifo_dma_out_prepare(&fifo, sg, ARRAY_SIZE(sg), 8);
+ printk(KERN_INFO "DMA sgl entries: %d\n", ret);
+
+ /* if 0 was returned, no data was available and no sgl was created */
+ if (ret) {
+ printk(KERN_INFO "scatterlist for transmit:\n");
+ for (i = 0; i < ARRAY_SIZE(sg); i++) {
+ printk(KERN_INFO
+ "sg[%d] -> "
+ "page_link 0x%.8lx offset 0x%.8x length 0x%.8x\n",
+ i, sg[i].page_link, sg[i].offset, sg[i].length);
+
+ if (sg_is_last(&sg[i]))
+ break;
+ }
+
+ /* but here your code to setup and exectute the dma operation */
+ /* ... */
+
+ /* example: 5 bytes transmitted */
+ ret = 5;
+
+ /* finish the dma operation and update the transmitted data */
+ kfifo_dma_out_finish(&fifo, ret);
+ }
+
+ printk(KERN_INFO "queue len: %u\n", kfifo_len(&fifo));
+
+ return 0;
+}
+
+static void __exit example_exit(void)
+{
+#ifdef DYNAMIC
+ kfifo_free(&test);
+#endif
+}
+
+module_init(example_init);
+module_exit(example_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Stefani Seibold <stefani@seibold.net>");
diff -u -N -r -p linux-2.6.33-rc7.orig/samples/kfifo/inttype-example.c linux-2.6.33-rc7.new/samples/kfifo/inttype-example.c
--- linux-2.6.33-rc7.orig/samples/kfifo/inttype-example.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.33-rc7.new/samples/kfifo/inttype-example.c 2010-02-12 08:32:18.252420182 +0100
@@ -0,0 +1,157 @@
+/*
+ * Sample kfifo int type implementation
+ *
+ * Copyright (C) 2010 Stefani Seibold <stefani@seibold.net>
+ *
+ * Released under the GPL version 2 only.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/mutex.h>
+#include <linux/kfifo.h>
+
+/*
+ * This module shows how to create a int type fifo.
+ */
+
+/* fifo size in elements (ints) */
+#define FIFO_SIZE 32
+
+/* name of the proc entry */
+#define PROC_FIFO "int-fifo"
+
+/* lock for procfs read access */
+static DEFINE_MUTEX(read_lock);
+
+/* lock for procfs write access */
+static DEFINE_MUTEX(write_lock);
+
+/*
+ * define DYNAMIC in this example for a dynamically allocated fifo.
+ *
+ * Otherwise the fifo storage will be a part of the fifo structure.
+ */
+#if 0
+#define DYNAMIC
+#endif
+
+#ifdef DYNAMIC
+static DECLARE_KFIFO_PTR(test, int);
+#else
+static DEFINE_KFIFO(test, int, FIFO_SIZE);
+#endif
+
+static int __init testfunc(void)
+{
+ int buf[6];
+ int i;
+ unsigned int ret;
+
+ printk(KERN_INFO "int fifo test start\n");
+
+ /* put values into the fifo */
+ for (i = 0; i != 10; i++)
+ kfifo_put(&test, &i);
+
+ /* show the number of used elements */
+ printk(KERN_INFO "fifo len: %u\n", kfifo_len(&test));
+
+ /* get max of 2 elements from the fifo */
+ ret = kfifo_out(&test, buf, 2);
+ printk(KERN_INFO "ret: %d\n", ret);
+ /* and put it back to the end of the fifo */
+ ret = kfifo_in(&test, buf, ret);
+ printk(KERN_INFO "ret: %d\n", ret);
+
+ for (i = 20; i != 30; i++)
+ kfifo_put(&test, &i);
+
+ printk(KERN_INFO "queue len: %u\n", kfifo_len(&test));
+
+ /* show the first value without removing from the fifo */
+ if (kfifo_peek(&test, &i))
+ printk(KERN_INFO "%d\n", i);
+
+ /* print out all values in the fifo */
+ while (kfifo_get(&test, &i))
+ printk("%d ", i);
+ printk("\n");
+
+ return 0;
+}
+
+static ssize_t fifo_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int ret;
+ unsigned int copied;
+
+ if (mutex_lock_interruptible(&write_lock))
+ return -ERESTARTSYS;
+
+ ret = kfifo_from_user(&test, buf, count, &copied);
+
+ mutex_unlock(&write_lock);
+
+ return ret ? ret : copied;
+}
+
+static ssize_t fifo_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int ret;
+ unsigned int copied;
+
+ if (mutex_lock_interruptible(&read_lock))
+ return -ERESTARTSYS;
+
+ ret = kfifo_to_user(&test, buf, count, &copied);
+
+ mutex_unlock(&read_lock);
+
+ return ret ? ret : copied;
+}
+
+static const struct file_operations fifo_fops = {
+ .owner = THIS_MODULE,
+ .read = fifo_read,
+ .write = fifo_write,
+};
+
+static int __init example_init(void)
+{
+#ifdef DYNAMIC
+ int ret;
+
+ ret = kfifo_alloc(&test, FIFO_SIZE, GFP_KERNEL);
+ if (ret) {
+ printk(KERN_ERR "error kfifo_alloc\n");
+ return ret;
+ }
+#endif
+ testfunc();
+
+ if (proc_create(PROC_FIFO, 0, NULL, &fifo_fops) == NULL) {
+#ifdef DYNAMIC
+ kfifo_free(&test);
+#endif
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+static void __exit example_exit(void)
+{
+ remove_proc_entry(PROC_FIFO, NULL);
+#ifdef DYNAMIC
+ kfifo_free(&test);
+#endif
+}
+
+module_init(example_init);
+module_exit(example_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Stefani Seibold <stefani@seibold.net>");
diff -u -N -r -p linux-2.6.33-rc7.orig/samples/kfifo/Makefile linux-2.6.33-rc7.new/samples/kfifo/Makefile
--- linux-2.6.33-rc7.orig/samples/kfifo/Makefile 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.33-rc7.new/samples/kfifo/Makefile 2010-02-12 08:31:54.107750622 +0100
@@ -0,0 +1 @@
+obj-$(CONFIG_SAMPLE_KFIFO) += bytestream-example.o dma-example.o inttype-example.o record-example.o
diff -u -N -r -p linux-2.6.33-rc7.orig/samples/kfifo/record-example.c linux-2.6.33-rc7.new/samples/kfifo/record-example.c
--- linux-2.6.33-rc7.orig/samples/kfifo/record-example.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.33-rc7.new/samples/kfifo/record-example.c 2010-02-12 08:32:18.252420182 +0100
@@ -0,0 +1,167 @@
+/*
+ * Sample dynamic sized record fifo implementation
+ *
+ * Copyright (C) 2010 Stefani Seibold <stefani@seibold.net>
+ *
+ * Released under the GPL version 2 only.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/mutex.h>
+#include <linux/kfifo.h>
+
+/*
+ * This module shows how to create a variable sized record fifo.
+ */
+
+/* fifo size in elements (bytes) */
+#define FIFO_SIZE 128
+
+/* name of the proc entry */
+#define PROC_FIFO "record-fifo"
+
+/* lock for procfs read access */
+static DEFINE_MUTEX(read_lock);
+
+/* lock for procfs write access */
+static DEFINE_MUTEX(write_lock);
+
+/*
+ * define DYNAMIC in this example for a dynamically allocated fifo.
+ *
+ * Otherwise the fifo storage will be a part of the fifo structure.
+ */
+#if 0
+#define DYNAMIC
+#endif
+
+/*
+ * struct kfifo_rec_ptr_1 and STRUCT_KFIFO_REC_1 can handle records of a
+ * length between 0 and 255 bytes.
+ *
+ * struct kfifo_rec_ptr_2 and STRUCT_KFIFO_REC_2 can handle records of a
+ * length between 0 and 65535 bytes.
+ */
+
+#ifdef DYNAMIC
+struct kfifo_rec_ptr_1 test;
+
+#else
+typedef STRUCT_KFIFO_REC_1(FIFO_SIZE) mytest;
+
+static mytest test;
+#endif
+
+static int __init testfunc(void)
+{
+ char buf[100];
+ unsigned int i;
+ unsigned int ret;
+ struct { unsigned char buf[6]; } hello = { "hello" };
+
+ printk(KERN_INFO "record fifo test start\n");
+
+ kfifo_in(&test, &hello, sizeof(hello));
+
+ /* show the size of the next record in the fifo */
+ printk(KERN_INFO "fifo peek len: %u\n", kfifo_peek_len(&test));
+
+ /* put in variable length data */
+ for (i = 0; i < 10; i++) {
+ memset(buf, 'a' + i, i + 1);
+ kfifo_in(&test, buf, i + 1);
+ }
+
+ printk(KERN_INFO "fifo len: %u\n", kfifo_len(&test));
+
+ /* show the first record without removing from the fifo */
+ ret = kfifo_out_peek(&test, buf, sizeof(buf));
+ if (ret)
+ printk(KERN_INFO "%.*s\n", ret, buf);
+
+ /* print out all records in the fifo */
+ while (!kfifo_is_empty(&test)) {
+ ret = kfifo_out(&test, buf, sizeof(buf));
+ printk(KERN_INFO "%.*s\n", ret, buf);
+ }
+
+ return 0;
+}
+
+static ssize_t fifo_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int ret;
+ unsigned int copied;
+
+ if (mutex_lock_interruptible(&write_lock))
+ return -ERESTARTSYS;
+
+ ret = kfifo_from_user(&test, buf, count, &copied);
+
+ mutex_unlock(&write_lock);
+
+ return ret ? ret : copied;
+}
+
+static ssize_t fifo_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int ret;
+ unsigned int copied;
+
+ if (mutex_lock_interruptible(&read_lock))
+ return -ERESTARTSYS;
+
+ ret = kfifo_to_user(&test, buf, count, &copied);
+
+ mutex_unlock(&read_lock);
+
+ return ret ? ret : copied;
+}
+
+static const struct file_operations fifo_fops = {
+ .owner = THIS_MODULE,
+ .read = fifo_read,
+ .write = fifo_write,
+};
+
+static int __init example_init(void)
+{
+#ifdef DYNAMIC
+ int ret;
+
+ ret = kfifo_alloc(&test, FIFO_SIZE, GFP_KERNEL);
+ if (ret) {
+ printk(KERN_ERR "error kfifo_alloc\n");
+ return ret;
+ }
+#else
+ INIT_KFIFO(test);
+#endif
+ testfunc();
+
+ if (proc_create(PROC_FIFO, 0, NULL, &fifo_fops) == NULL) {
+#ifdef DYNAMIC
+ kfifo_free(&test);
+#endif
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+static void __exit example_exit(void)
+{
+ remove_proc_entry(PROC_FIFO, NULL);
+#ifdef DYNAMIC
+ kfifo_free(&test);
+#endif
+}
+
+module_init(example_init);
+module_exit(example_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Stefani Seibold <stefani@seibold.net>");
diff -u -N -r -p linux-2.6.33-rc7.orig/samples/Makefile linux-2.6.33-rc7.new/samples/Makefile
--- linux-2.6.33-rc7.orig/samples/Makefile 2010-02-11 17:05:58.178434640 +0100
+++ linux-2.6.33-rc7.new/samples/Makefile 2010-02-12 08:31:54.107750622 +0100
@@ -1,4 +1,4 @@
# Makefile for Linux samples code
obj-$(CONFIG_SAMPLES) += kobject/ kprobes/ tracepoints/ trace_events/ \
- hw_breakpoint/
+ hw_breakpoint/ kfifo/
^ permalink raw reply [flat|nested] 13+ messages in thread* Enhanced reimplemention of the kfifo API request for merge
2010-02-12 7:52 [PATCH 0/4] enhanced reimplemention of the kfifo API Stefani Seibold
` (3 preceding siblings ...)
2010-02-12 8:07 ` [PATCH 4/4] add example files to the kernel sample directory Stefani Seibold
@ 2010-02-19 9:39 ` Stefani Seibold
4 siblings, 0 replies; 13+ messages in thread
From: Stefani Seibold @ 2010-02-19 9:39 UTC (permalink / raw)
To: linux-kernel
Cc: Andrew Morton, Andi Kleen, Greg Kroah-Hartman, Alan Cox,
Theodore Tso, Ira W. Snyder, Linus Torvalds
Hi,
is there a change to get the new generic kfifo API merged into the
linux-next, mm- or the upcoming 2.6.34 tree?
All features and complains are implemented. I got a lot of commits and
positve feedback but no ack's.
So the question is should i continue to work?
If i get an okay for the merge, the next steps will be:
- add a short HOWTO file into the Documentation directory
- replace all kfifo_out_locked() into kfifo_out_spinlocked() and
replace all kfifo_in_locked() into kfifo_in_spinlocked()
- modify the drivers to use the type based FIFO
- maybe port drivers which use its own fifo implementation to the new
kfifo API
Stefani ;-)
^ permalink raw reply [flat|nested] 13+ messages in thread