From 45465487897a1c6d508b14b904dc5777f7ec7e04 Mon Sep 17 00:00:00 2001 From: Stefani Seibold Date: Mon, 21 Dec 2009 14:37:26 -0800 Subject: kfifo: move struct kfifo in place This is a new generic kernel FIFO implementation. The current kernel fifo API is not very widely used, because it has to many constrains. Only 17 files in the current 2.6.31-rc5 used it. FIFO's are like list's a very basic thing and a kfifo API which handles the most use case would save a lot of development time and memory resources. I think this are the reasons why kfifo is not in use: - The API is to simple, important functions are missing - A fifo can be only allocated dynamically - There is a requirement of a spinlock whether you need it or not - There is no support for data records inside a fifo So I decided to extend the kfifo in a more generic way without blowing up the API to much. The new API has the following benefits: - Generic usage: For kernel internal use and/or device driver. - Provide an API for the most use case. - Slim API: The whole API provides 25 functions. - Linux style habit. - DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros - Direct copy_to_user from the fifo and copy_from_user into the fifo. - The kfifo itself is an in place member of the using data structure, this save an indirection access and does not waste the kernel allocator. - Lockless access: if only one reader and one writer is active on the fifo, which is the common use case, no additional locking is necessary. - Remove spinlock - give the user the freedom of choice what kind of locking to use if one is required. - Ability to handle records. Three type of records are supported: - Variable length records between 0-255 bytes, with a record size field of 1 bytes. - Variable length records between 0-65535 bytes, with a record size field of 2 bytes. - Fixed size records, which no record size field. - Preserve memory resource. - Performance! - Easy to use! This patch: Since most users want to have the kfifo as part of another object, reorganize the code to allow including struct kfifo in another data structure. This requires changing the kfifo_alloc and kfifo_init prototypes so that we pass an existing kfifo pointer into them. This patch changes the implementation and all existing users. [akpm@linux-foundation.org: fix warning] Signed-off-by: Stefani Seibold Acked-by: Greg Kroah-Hartman Acked-by: Mauro Carvalho Chehab Acked-by: Andi Kleen Acked-by: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kfifo.c | 65 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 33 insertions(+), 32 deletions(-) (limited to 'kernel/kfifo.c') diff --git a/kernel/kfifo.c b/kernel/kfifo.c index 3765ff3c1bbe..8da6bb9782bb 100644 --- a/kernel/kfifo.c +++ b/kernel/kfifo.c @@ -1,6 +1,7 @@ /* - * A simple kernel FIFO implementation. + * A generic kernel FIFO implementation. * + * Copyright (C) 2009 Stefani Seibold * Copyright (C) 2004 Stelian Pop * * This program is free software; you can redistribute it and/or modify @@ -26,49 +27,51 @@ #include #include +static void _kfifo_init(struct kfifo *fifo, unsigned char *buffer, + unsigned int size, spinlock_t *lock) +{ + fifo->buffer = buffer; + fifo->size = size; + fifo->lock = lock; + + kfifo_reset(fifo); +} + /** - * kfifo_init - allocates a new FIFO using a preallocated buffer + * 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. - * @gfp_mask: get_free_pages mask, passed to kmalloc() * @lock: the lock to be used to protect the fifo buffer * - * Do NOT pass the kfifo to kfifo_free() after use! Simply free the - * &struct kfifo with kfree(). */ -struct kfifo *kfifo_init(unsigned char *buffer, unsigned int size, - gfp_t gfp_mask, spinlock_t *lock) +void kfifo_init(struct kfifo *fifo, unsigned char *buffer, unsigned int size, + spinlock_t *lock) { - struct kfifo *fifo; - /* size must be a power of 2 */ BUG_ON(!is_power_of_2(size)); - fifo = kmalloc(sizeof(struct kfifo), gfp_mask); - if (!fifo) - return ERR_PTR(-ENOMEM); - - fifo->buffer = buffer; - fifo->size = size; - fifo->in = fifo->out = 0; - fifo->lock = lock; - - return fifo; + _kfifo_init(fifo, buffer, size, lock); } EXPORT_SYMBOL(kfifo_init); /** - * kfifo_alloc - allocates a new FIFO and its internal buffer - * @size: the size of the internal buffer to be allocated. + * 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() * @lock: the lock to be used to protect the fifo buffer * + * 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 */ -struct kfifo *kfifo_alloc(unsigned int size, gfp_t gfp_mask, spinlock_t *lock) +int kfifo_alloc(struct kfifo *fifo, unsigned int size, gfp_t gfp_mask, + spinlock_t *lock) { unsigned char *buffer; - struct kfifo *ret; /* * round up to the next power of 2, since our 'let the indices @@ -80,26 +83,24 @@ struct kfifo *kfifo_alloc(unsigned int size, gfp_t gfp_mask, spinlock_t *lock) } buffer = kmalloc(size, gfp_mask); - if (!buffer) - return ERR_PTR(-ENOMEM); - - ret = kfifo_init(buffer, size, gfp_mask, lock); + if (!buffer) { + _kfifo_init(fifo, 0, 0, NULL); + return -ENOMEM; + } - if (IS_ERR(ret)) - kfree(buffer); + _kfifo_init(fifo, buffer, size, lock); - return ret; + return 0; } EXPORT_SYMBOL(kfifo_alloc); /** - * kfifo_free - frees the FIFO + * kfifo_free - frees the FIFO internal buffer * @fifo: the fifo to be freed. */ void kfifo_free(struct kfifo *fifo) { kfree(fifo->buffer); - kfree(fifo); } EXPORT_SYMBOL(kfifo_free); -- cgit v1.2.3 From c1e13f25674ed564948ecb7dfe5f83e578892896 Mon Sep 17 00:00:00 2001 From: Stefani Seibold Date: Mon, 21 Dec 2009 14:37:27 -0800 Subject: kfifo: move out spinlock Move the pointer to the spinlock out of struct kfifo. Most users in tree do not actually use a spinlock, so the few exceptions now have to call kfifo_{get,put}_locked, which takes an extra argument to a spinlock. Signed-off-by: Stefani Seibold Acked-by: Greg Kroah-Hartman Acked-by: Mauro Carvalho Chehab Acked-by: Andi Kleen Acked-by: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kfifo.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) (limited to 'kernel/kfifo.c') diff --git a/kernel/kfifo.c b/kernel/kfifo.c index 8da6bb9782bb..4950bdbe3477 100644 --- a/kernel/kfifo.c +++ b/kernel/kfifo.c @@ -28,11 +28,10 @@ #include static void _kfifo_init(struct kfifo *fifo, unsigned char *buffer, - unsigned int size, spinlock_t *lock) + unsigned int size) { fifo->buffer = buffer; fifo->size = size; - fifo->lock = lock; kfifo_reset(fifo); } @@ -42,16 +41,14 @@ static void _kfifo_init(struct kfifo *fifo, unsigned char *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. - * @lock: the lock to be used to protect the fifo buffer * */ -void kfifo_init(struct kfifo *fifo, unsigned char *buffer, unsigned int size, - spinlock_t *lock) +void kfifo_init(struct kfifo *fifo, unsigned char *buffer, unsigned int size) { /* size must be a power of 2 */ BUG_ON(!is_power_of_2(size)); - _kfifo_init(fifo, buffer, size, lock); + _kfifo_init(fifo, buffer, size); } EXPORT_SYMBOL(kfifo_init); @@ -60,7 +57,6 @@ EXPORT_SYMBOL(kfifo_init); * @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() - * @lock: the lock to be used to protect the fifo buffer * * This function dynamically allocates a new fifo internal buffer * @@ -68,8 +64,7 @@ EXPORT_SYMBOL(kfifo_init); * 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, - spinlock_t *lock) +int kfifo_alloc(struct kfifo *fifo, unsigned int size, gfp_t gfp_mask) { unsigned char *buffer; @@ -84,11 +79,11 @@ int kfifo_alloc(struct kfifo *fifo, unsigned int size, gfp_t gfp_mask, buffer = kmalloc(size, gfp_mask); if (!buffer) { - _kfifo_init(fifo, 0, 0, NULL); + _kfifo_init(fifo, 0, 0); return -ENOMEM; } - _kfifo_init(fifo, buffer, size, lock); + _kfifo_init(fifo, buffer, size); return 0; } -- cgit v1.2.3 From e64c026dd09b73faf20707711402fc5ed55a8e70 Mon Sep 17 00:00:00 2001 From: Stefani Seibold Date: Mon, 21 Dec 2009 14:37:28 -0800 Subject: kfifo: cleanup namespace change name of __kfifo_* functions to kfifo_*, because the prefix __kfifo should be reserved for internal functions only. Signed-off-by: Stefani Seibold Acked-by: Greg Kroah-Hartman Acked-by: Mauro Carvalho Chehab Acked-by: Andi Kleen Acked-by: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kfifo.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'kernel/kfifo.c') diff --git a/kernel/kfifo.c b/kernel/kfifo.c index 4950bdbe3477..963ffde4af1a 100644 --- a/kernel/kfifo.c +++ b/kernel/kfifo.c @@ -100,7 +100,7 @@ void kfifo_free(struct kfifo *fifo) EXPORT_SYMBOL(kfifo_free); /** - * __kfifo_put - puts some data into the FIFO, no locking version + * kfifo_put - puts some data into the FIFO, no locking version * @fifo: the fifo to be used. * @buffer: the data to be added. * @len: the length of the data to be added. @@ -112,7 +112,7 @@ EXPORT_SYMBOL(kfifo_free); * Note that with only one concurrent reader and one concurrent * writer, you don't need extra locking to use these functions. */ -unsigned int __kfifo_put(struct kfifo *fifo, +unsigned int kfifo_put(struct kfifo *fifo, const unsigned char *buffer, unsigned int len) { unsigned int l; @@ -144,10 +144,10 @@ unsigned int __kfifo_put(struct kfifo *fifo, return len; } -EXPORT_SYMBOL(__kfifo_put); +EXPORT_SYMBOL(kfifo_put); /** - * __kfifo_get - gets some data from the FIFO, no locking version + * kfifo_get - gets some data from the FIFO, no locking version * @fifo: the fifo to be used. * @buffer: where the data must be copied. * @len: the size of the destination buffer. @@ -158,7 +158,7 @@ EXPORT_SYMBOL(__kfifo_put); * Note that with only one concurrent reader and one concurrent * writer, you don't need extra locking to use these functions. */ -unsigned int __kfifo_get(struct kfifo *fifo, +unsigned int kfifo_get(struct kfifo *fifo, unsigned char *buffer, unsigned int len) { unsigned int l; @@ -190,4 +190,4 @@ unsigned int __kfifo_get(struct kfifo *fifo, return len; } -EXPORT_SYMBOL(__kfifo_get); +EXPORT_SYMBOL(kfifo_get); -- cgit v1.2.3 From 7acd72eb85f1c7a15e8b5eb554994949241737f1 Mon Sep 17 00:00:00 2001 From: Stefani Seibold Date: Mon, 21 Dec 2009 14:37:28 -0800 Subject: kfifo: rename kfifo_put... into kfifo_in... and kfifo_get... into kfifo_out... rename kfifo_put... into kfifo_in... to prevent miss use of old non in kernel-tree drivers ditto for kfifo_get... -> kfifo_out... Improve the prototypes of kfifo_in and kfifo_out to make the kerneldoc annotations more readable. Add mini "howto porting to the new API" in kfifo.h Signed-off-by: Stefani Seibold Acked-by: Greg Kroah-Hartman Acked-by: Mauro Carvalho Chehab Acked-by: Andi Kleen Acked-by: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kfifo.c | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) (limited to 'kernel/kfifo.c') diff --git a/kernel/kfifo.c b/kernel/kfifo.c index 963ffde4af1a..d659442e73f2 100644 --- a/kernel/kfifo.c +++ b/kernel/kfifo.c @@ -100,20 +100,20 @@ void kfifo_free(struct kfifo *fifo) EXPORT_SYMBOL(kfifo_free); /** - * kfifo_put - puts some data into the FIFO, no locking version + * kfifo_in - puts some data into the FIFO * @fifo: the fifo to be used. - * @buffer: the data to be added. + * @from: the data to be added. * @len: the length of the data to be added. * - * This function copies at most @len bytes from the @buffer into + * 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_put(struct kfifo *fifo, - const unsigned char *buffer, unsigned int len) +unsigned int kfifo_in(struct kfifo *fifo, + const unsigned char *from, unsigned int len) { unsigned int l; @@ -128,10 +128,10 @@ unsigned int kfifo_put(struct kfifo *fifo, /* first put the data starting from fifo->in to buffer end */ l = min(len, fifo->size - (fifo->in & (fifo->size - 1))); - memcpy(fifo->buffer + (fifo->in & (fifo->size - 1)), buffer, l); + memcpy(fifo->buffer + (fifo->in & (fifo->size - 1)), from, l); /* then put the rest (if any) at the beginning of the buffer */ - memcpy(fifo->buffer, buffer + l, len - l); + memcpy(fifo->buffer, from + l, len - l); /* * Ensure that we add the bytes to the kfifo -before- @@ -144,22 +144,22 @@ unsigned int kfifo_put(struct kfifo *fifo, return len; } -EXPORT_SYMBOL(kfifo_put); +EXPORT_SYMBOL(kfifo_in); /** - * kfifo_get - gets some data from the FIFO, no locking version + * kfifo_out - gets some data from the FIFO * @fifo: the fifo to be used. - * @buffer: where the data must be copied. + * @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 - * @buffer and returns the number of copied bytes. + * @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_get(struct kfifo *fifo, - unsigned char *buffer, unsigned int len) +unsigned int kfifo_out(struct kfifo *fifo, + unsigned char *to, unsigned int len) { unsigned int l; @@ -174,10 +174,10 @@ unsigned int kfifo_get(struct kfifo *fifo, /* first get the data from fifo->out until the end of the buffer */ l = min(len, fifo->size - (fifo->out & (fifo->size - 1))); - memcpy(buffer, fifo->buffer + (fifo->out & (fifo->size - 1)), l); + memcpy(to, fifo->buffer + (fifo->out & (fifo->size - 1)), l); /* then get the rest (if any) from the beginning of the buffer */ - memcpy(buffer + l, fifo->buffer, len - l); + memcpy(to + l, fifo->buffer, len - l); /* * Ensure that we remove the bytes from the kfifo -before- @@ -190,4 +190,4 @@ unsigned int kfifo_get(struct kfifo *fifo, return len; } -EXPORT_SYMBOL(kfifo_get); +EXPORT_SYMBOL(kfifo_out); -- cgit v1.2.3 From a121f24accac1600bf5b6fb1e12eeabdfed7cb1a Mon Sep 17 00:00:00 2001 From: Stefani Seibold Date: Mon, 21 Dec 2009 14:37:31 -0800 Subject: kfifo: add kfifo_skip, kfifo_from_user and kfifo_to_user Add kfifo_reset_out() for save lockless discard the fifo output Add kfifo_skip() to skip a number of output bytes Add kfifo_from_user() to copy user space data into the fifo Add kfifo_to_user() to copy fifo data to user space Signed-off-by: Stefani Seibold Acked-by: Greg Kroah-Hartman Acked-by: Mauro Carvalho Chehab Acked-by: Andi Kleen Acked-by: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kfifo.c | 139 ++++++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 123 insertions(+), 16 deletions(-) (limited to 'kernel/kfifo.c') diff --git a/kernel/kfifo.c b/kernel/kfifo.c index d659442e73f2..2a78425ef67f 100644 --- a/kernel/kfifo.c +++ b/kernel/kfifo.c @@ -26,6 +26,7 @@ #include #include #include +#include static void _kfifo_init(struct kfifo *fifo, unsigned char *buffer, unsigned int size) @@ -99,6 +100,21 @@ void kfifo_free(struct kfifo *fifo) } 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); + /** * kfifo_in - puts some data into the FIFO * @fifo: the fifo to be used. @@ -115,6 +131,7 @@ EXPORT_SYMBOL(kfifo_free); unsigned int kfifo_in(struct kfifo *fifo, const unsigned char *from, unsigned int len) { + unsigned int off; unsigned int l; len = min(len, fifo->size - fifo->in + fifo->out); @@ -126,21 +143,16 @@ unsigned int kfifo_in(struct kfifo *fifo, smp_mb(); + off = __kfifo_off(fifo, fifo->in); + /* first put the data starting from fifo->in to buffer end */ - l = min(len, fifo->size - (fifo->in & (fifo->size - 1))); - memcpy(fifo->buffer + (fifo->in & (fifo->size - 1)), from, l); + 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); - /* - * Ensure that we add the bytes to the kfifo -before- - * we update the fifo->in index. - */ - - smp_wmb(); - - fifo->in += len; + __kfifo_add_in(fifo, len); return len; } @@ -161,6 +173,7 @@ EXPORT_SYMBOL(kfifo_in); unsigned int kfifo_out(struct kfifo *fifo, unsigned char *to, unsigned int len) { + unsigned int off; unsigned int l; len = min(len, fifo->in - fifo->out); @@ -172,22 +185,116 @@ unsigned int kfifo_out(struct kfifo *fifo, smp_rmb(); + off = __kfifo_off(fifo, fifo->out); + /* first get the data from fifo->out until the end of the buffer */ - l = min(len, fifo->size - (fifo->out & (fifo->size - 1))); - memcpy(to, fifo->buffer + (fifo->out & (fifo->size - 1)), l); + 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); + __kfifo_add_out(fifo, len); + + return len; +} +EXPORT_SYMBOL(kfifo_out); + +/** + * 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. + * + * This function copies at most @len bytes from the @from into the + * FIFO depending 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_from_user(struct kfifo *fifo, + const void __user *from, unsigned int len) +{ + unsigned int off; + unsigned int l; + int ret; + + len = min(len, fifo->size - fifo->in + fifo->out); + /* - * Ensure that we remove the bytes from the kfifo -before- - * we update the fifo->out index. + * Ensure that we sample the fifo->out index -before- we + * start putting bytes into the kfifo. */ smp_mb(); - fifo->out += len; + off = __kfifo_off(fifo, fifo->in); + + /* 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)) + return l - ret; + + /* then put the rest (if any) at the beginning of the buffer */ + ret = copy_from_user(fifo->buffer, from + l, len - l); + + if (unlikely(ret)) + return len - ret; + + __kfifo_add_in(fifo, len); return len; } -EXPORT_SYMBOL(kfifo_out); +EXPORT_SYMBOL(kfifo_from_user); + +/** + * 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. + * + * 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_to_user(struct kfifo *fifo, + void __user *to, unsigned int len) +{ + unsigned int off; + unsigned int l; + int ret; + + len = min(len, fifo->in - fifo->out); + + /* + * Ensure that we sample the fifo->in index -before- we + * start removing bytes from the kfifo. + */ + + smp_rmb(); + + off = __kfifo_off(fifo, fifo->out); + + /* 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); + + if (unlikely(ret)) + return l - ret; + + /* then get the rest (if any) from the beginning of the buffer */ + ret = copy_to_user(to + l, fifo->buffer, len - l); + + if (unlikely(ret)) + return len - ret; + + __kfifo_add_out(fifo, len); + + return len; +} +EXPORT_SYMBOL(kfifo_to_user); + -- cgit v1.2.3 From 86d4880313603810901f639ccb5c88ff13d4ad3c Mon Sep 17 00:00:00 2001 From: Stefani Seibold Date: Mon, 21 Dec 2009 14:37:32 -0800 Subject: kfifo: add record handling functions Add kfifo_in_rec() - puts some record data into the FIFO Add kfifo_out_rec() - gets some record data from the FIFO Add kfifo_from_user_rec() - puts some data from user space into the FIFO Add kfifo_to_user_rec() - gets data from the FIFO and write it to user space Add kfifo_peek_rec() - gets the size of the next FIFO record field Add kfifo_skip_rec() - skip the next fifo out record Add kfifo_avail_rec() - determinate the number of bytes available in a record FIFO Signed-off-by: Stefani Seibold Acked-by: Greg Kroah-Hartman Acked-by: Mauro Carvalho Chehab Acked-by: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kfifo.c | 286 ++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 193 insertions(+), 93 deletions(-) (limited to 'kernel/kfifo.c') diff --git a/kernel/kfifo.c b/kernel/kfifo.c index 2a78425ef67f..e92d519f93b1 100644 --- a/kernel/kfifo.c +++ b/kernel/kfifo.c @@ -115,27 +115,11 @@ void kfifo_skip(struct kfifo *fifo, unsigned int len) } EXPORT_SYMBOL(kfifo_skip); -/** - * 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 unsigned char *from, unsigned int len) +static inline void __kfifo_in_data(struct kfifo *fifo, + const void *from, unsigned int len, unsigned int off) { - unsigned int off; unsigned int l; - len = min(len, fifo->size - fifo->in + fifo->out); - /* * Ensure that we sample the fifo->out index -before- we * start putting bytes into the kfifo. @@ -143,7 +127,7 @@ unsigned int kfifo_in(struct kfifo *fifo, smp_mb(); - off = __kfifo_off(fifo, fifo->in); + off = __kfifo_off(fifo, fifo->in + off); /* first put the data starting from fifo->in to buffer end */ l = min(len, fifo->size - off); @@ -151,33 +135,13 @@ unsigned int kfifo_in(struct kfifo *fifo, /* then put the rest (if any) at the beginning of the buffer */ memcpy(fifo->buffer, from + l, len - l); - - __kfifo_add_in(fifo, len); - - return len; } -EXPORT_SYMBOL(kfifo_in); -/** - * 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, - unsigned char *to, unsigned int len) +static inline void __kfifo_out_data(struct kfifo *fifo, + void *to, unsigned int len, unsigned int off) { - unsigned int off; unsigned int l; - len = min(len, fifo->in - fifo->out); - /* * Ensure that we sample the fifo->in index -before- we * start removing bytes from the kfifo. @@ -185,7 +149,7 @@ unsigned int kfifo_out(struct kfifo *fifo, smp_rmb(); - off = __kfifo_off(fifo, fifo->out); + 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); @@ -193,34 +157,14 @@ unsigned int kfifo_out(struct kfifo *fifo, /* then get the rest (if any) from the beginning of the buffer */ memcpy(to + l, fifo->buffer, len - l); - - __kfifo_add_out(fifo, len); - - return len; } -EXPORT_SYMBOL(kfifo_out); -/** - * 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. - * - * This function copies at most @len bytes from the @from into the - * FIFO depending 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_from_user(struct kfifo *fifo, - const void __user *from, unsigned int len) +static inline unsigned int __kfifo_from_user_data(struct kfifo *fifo, + const void __user *from, unsigned int len, unsigned int off) { - unsigned int off; unsigned int l; int ret; - len = min(len, fifo->size - fifo->in + fifo->out); - /* * Ensure that we sample the fifo->out index -before- we * start putting bytes into the kfifo. @@ -228,29 +172,101 @@ unsigned int kfifo_from_user(struct kfifo *fifo, smp_mb(); - off = __kfifo_off(fifo, fifo->in); + 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)) - return l - ret; + return ret + len - l; /* then put the rest (if any) at the beginning of the buffer */ - ret = copy_from_user(fifo->buffer, from + l, len - l); + return copy_from_user(fifo->buffer, from + l, len - l); +} + +static inline unsigned int __kfifo_to_user_data(struct kfifo *fifo, + void __user *to, unsigned int len, unsigned int off) +{ + 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); if (unlikely(ret)) - return len - ret; + return ret + len - l; - __kfifo_add_in(fifo, len); + /* then get the rest (if any) from the beginning of the buffer */ + return copy_to_user(to + l, fifo->buffer, len - l); +} +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 unsigned char *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_from_user); +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_to_user - gets data from the FIFO and write it to user space + * 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. @@ -261,40 +277,124 @@ EXPORT_SYMBOL(kfifo_from_user); * Note that with only one concurrent reader and one concurrent * writer, you don't need extra locking to use these functions. */ -unsigned int kfifo_to_user(struct kfifo *fifo, - void __user *to, unsigned int len) +unsigned int kfifo_out(struct kfifo *fifo, unsigned char *to, unsigned int len) { - unsigned int off; - unsigned int l; - int ret; + len = min(kfifo_len(fifo), len); - len = min(len, fifo->in - fifo->out); + __kfifo_out_data(fifo, to, len, 0); + __kfifo_add_out(fifo, len); - /* - * Ensure that we sample the fifo->in index -before- we - * start removing bytes from the kfifo. - */ + return len; +} +EXPORT_SYMBOL(kfifo_out); - smp_rmb(); +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); - off = __kfifo_off(fifo, fifo->out); +unsigned int __kfifo_from_user_n(struct kfifo *fifo, + const void __user *from, unsigned int len, unsigned int recsize) +{ + if (kfifo_avail(fifo) < len + recsize) + return len + 1; - /* 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); + return __kfifo_from_user_data(fifo, from, len, recsize); +} +EXPORT_SYMBOL(__kfifo_from_user_n); - if (unlikely(ret)) - return l - ret; +/** + * 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. + * + * This function copies at most @len bytes from the @from into the + * FIFO depending 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_from_user(struct kfifo *fifo, + const void __user *from, unsigned int len) +{ + len = min(kfifo_avail(fifo), len); + len -= __kfifo_from_user_data(fifo, from, len, 0); + __kfifo_add_in(fifo, len); + return len; +} +EXPORT_SYMBOL(kfifo_from_user); - /* then get the rest (if any) from the beginning of the buffer */ - ret = copy_to_user(to + l, fifo->buffer, len - l); +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); - if (unlikely(ret)) - return len - ret; +unsigned int __kfifo_to_user_n(struct kfifo *fifo, + void __user *to, unsigned int len, unsigned int reclen, + unsigned int recsize) +{ + unsigned int ret; - __kfifo_add_out(fifo, len); + if (kfifo_len(fifo) < reclen + recsize) + return len; + ret = __kfifo_to_user_data(fifo, to, reclen, recsize); + + if (likely(ret == 0)) + __kfifo_add_out(fifo, reclen + recsize); + + return ret; +} +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. + * + * 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_to_user(struct kfifo *fifo, + void __user *to, unsigned int len) +{ + len = min(kfifo_len(fifo), len); + len -= __kfifo_to_user_data(fifo, to, len, 0); + __kfifo_add_out(fifo, len); return len; } 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); + -- cgit v1.2.3