<title>FIFO Buffer</title>
<sect1><title>kfifo interface</title>
!Iinclude/linux/kfifo.h
-!Ekernel/kfifo.c
</sect1>
</chapter>
+++ /dev/null
-/*
- * 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
/*
- * A generic kernel FIFO implementation.
+ * A generic kernel FIFO implementation
*
- * Copyright (C) 2009 Stefani Seibold <stefani@seibold.net>
- * Copyright (C) 2004 Stelian Pop <stelian@popies.net>
+ * 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
*
*/
+#ifndef _LINUX_KFIFO_H
+#define _LINUX_KFIFO_H
+
/*
- * Howto porting drivers to the new generic fifo API:
+ * 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
* 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
+ * - 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_locked and kfifo_out_locked
- * as the last parameter.
- * - All formerly name __kfifo_* functions has been renamed into kfifo_*
+ * 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_*
*/
-#ifndef _LINUX_KFIFO_H
-#define _LINUX_KFIFO_H
+/*
+ * 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>
-
-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) */
+#include <linux/stddef.h>
+#include <linux/scatterlist.h>
+
+struct __kfifo {
+ unsigned int in;
+ unsigned int out;
+ unsigned int mask;
+ unsigned int esize;
+ void *data;
};
-/*
- * 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 \
+#define __STRUCT_KFIFO_COMMON(datatype, recsize, ptrtype) \
+ union { \
+ struct __kfifo kfifo; \
+ datatype *type; \
+ char (*rectype)[recsize]; \
+ ptrtype *ptr; \
+ const ptrtype *ptr_const; \
}
-/**
- * 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)]; \
+#define __STRUCT_KFIFO(type, size, recsize, ptrtype) \
+{ \
+ __STRUCT_KFIFO_COMMON(type, recsize, ptrtype); \
+ type buf[((size < 2) || (size & (size - 1))) ? -1 : size]; \
}
-/**
- * INIT_KFIFO - Initialize a kfifo declared by DECLARE_KFIFO
- * @name: name of the declared kfifo datatype
+#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
*/
-#define INIT_KFIFO(name) \
- name = __kfifo_initializer(sizeof(name##kfifo_buffer) - \
- sizeof(struct kfifo), \
- name##kfifo_buffer + sizeof(struct kfifo))
+struct kfifo __STRUCT_KFIFO_PTR(unsigned char, 0, void);
-/**
- * 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 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
*/
-#define DEFINE_KFIFO(name, size) \
- unsigned char name##kfifo_buffer[size]; \
- struct kfifo name = __kfifo_initializer(size, name##kfifo_buffer)
+struct kfifo_rec_ptr_1 __STRUCT_KFIFO_PTR(unsigned char, 1, void);
+struct kfifo_rec_ptr_2 __STRUCT_KFIFO_PTR(unsigned char, 2, void);
-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);
+/*
+ * 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))
/**
- * 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.
+ * DECLARE_KFIFO_PTR - macro to declare a fifo pointer object
+ * @fifo: name of the declared fifo
+ * @type: type of the fifo elements
*/
-static inline bool kfifo_initialized(struct kfifo *fifo)
-{
- return fifo->buffer != NULL;
-}
+#define DECLARE_KFIFO_PTR(fifo, type) STRUCT_KFIFO_PTR(type) fifo
/**
- * kfifo_reset - removes the entire FIFO contents
- * @fifo: the fifo to be emptied.
+ * 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
*/
-static inline void kfifo_reset(struct kfifo *fifo)
-{
- fifo->in = fifo->out = 0;
-}
+#define DECLARE_KFIFO(fifo, type, size) STRUCT_KFIFO(type, size) fifo
/**
- * 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;
-}
+ * 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; \
+})
/**
- * 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)
+ * 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 fifo->size;
+ return val;
}
/**
- * kfifo_len - returns the number of used bytes in the FIFO
- * @fifo: the fifo to be used.
+ * 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.
*/
-static inline unsigned int kfifo_len(struct kfifo *fifo)
-{
- register unsigned int out;
-
- out = fifo->out;
- smp_rmb();
- return fifo->in - out;
-}
+#define kfifo_initialized(fifo) ((fifo)->kfifo.mask)
/**
- * kfifo_is_empty - returns true if the fifo is empty
- * @fifo: the fifo to be used.
+ * kfifo_esize - returns the size of the element managed by the fifo
+ * @fifo: address of the fifo to be used
*/
-static inline __must_check bool kfifo_is_empty(struct kfifo *fifo)
-{
- return fifo->in == fifo->out;
-}
+#define kfifo_esize(fifo) ((fifo)->kfifo.esize)
/**
- * kfifo_is_full - returns true if the fifo is full
- * @fifo: the fifo to be used.
+ * kfifo_recsize - returns the size of the record length field
+ * @fifo: address of the fifo to be used
*/
-static inline __must_check bool kfifo_is_full(struct kfifo *fifo)
-{
- return kfifo_len(fifo) == kfifo_size(fifo);
-}
+#define kfifo_recsize(fifo) (sizeof(*(fifo)->rectype))
/**
- * kfifo_avail - returns the number of bytes available in the FIFO
- * @fifo: the fifo to be used.
+ * kfifo_size - returns the size of the fifo in elements
+ * @fifo: address of the fifo to be used
*/
-static inline __must_check unsigned int kfifo_avail(struct kfifo *fifo)
-{
- return kfifo_size(fifo) - kfifo_len(fifo);
-}
+#define kfifo_size(fifo) ((fifo)->kfifo.mask + 1)
/**
- * 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.
+ * kfifo_reset - removes the entire fifo content
+ * @fifo: address of the fifo to be used
*
- * This function copies at most @n bytes from the @from buffer into
- * the FIFO depending on the free space, and returns the number of
- * bytes copied.
+ * 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.
*/
-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;
-}
+#define kfifo_reset(fifo) \
+(void)({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ __tmp->kfifo.in = __tmp->kfifo.out = 0; \
+})
/**
- * 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.
+ * kfifo_reset_out - skip fifo content
+ * @fifo: address of the fifo to be used
*
- * This function copies at most @n 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
+ * 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().
*/
-static inline void __kfifo_add_out(struct kfifo *fifo,
- unsigned int off)
-{
- smp_mb();
- fifo->out += off;
-}
+#define kfifo_reset_out(fifo) \
+(void)({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ __tmp->kfifo.out = __tmp->kfifo.in; \
+})
-/*
- * __kfifo_add_in internal helper function for updating the in offset
+/**
+ * kfifo_len - returns the number of used elements in the fifo
+ * @fifo: address of the fifo to be used
*/
-static inline void __kfifo_add_in(struct kfifo *fifo,
- unsigned int off)
-{
- smp_wmb();
- fifo->in += off;
-}
+#define kfifo_len(fifo) \
+({ \
+ typeof(fifo + 1) __tmpl = (fifo); \
+ __tmpl->kfifo.in - __tmpl->kfifo.out; \
+})
-/*
- * __kfifo_off internal helper function for calculating the index of a
- * given offeset
+/**
+ * kfifo_is_empty - returns true if the fifo is empty
+ * @fifo: address of the fifo to be used
*/
-static inline unsigned int __kfifo_off(struct kfifo *fifo, unsigned int off)
-{
- return off & (fifo->size - 1);
-}
+#define kfifo_is_empty(fifo) \
+({ \
+ typeof(fifo + 1) __tmpq = (fifo); \
+ __tmpq->kfifo.in == __tmpq->kfifo.out; \
+})
-/*
- * __kfifo_peek_n internal helper function for determinate the length of
- * the next record in the fifo
+/**
+ * kfifo_is_full - returns true if the fifo is full
+ * @fifo: address of the fifo to be used
*/
-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))
+#define kfifo_is_full(fifo) \
+({ \
+ typeof(fifo + 1) __tmpq = (fifo); \
+ kfifo_len(__tmpq) > __tmpq->kfifo.mask; \
+})
- unsigned int l;
+/**
+ * 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; \
+}) \
+)
- l = __KFIFO_GET(fifo, 0, 0);
+/**
+ * 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++; \
+})
- if (--recsize)
- l |= __KFIFO_GET(fifo, 1, 8);
+/**
+ * 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); \
+}) \
+)
- return l;
-#undef __KFIFO_GET
-}
+/**
+ * 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_poke_n internal helper function for storing the length of
- * the next record into the fifo
+/**
+ * kfifo_free - frees the fifo
+ * @fifo: the fifo to be freed
*/
-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)) \
- )
+#define kfifo_free(fifo) \
+({ \
+ typeof(fifo + 1) __tmp = (fifo); \
+ struct __kfifo *__kfifo = &__tmp->kfifo; \
+ if (__is_kfifo_ptr(__tmp)) \
+ __kfifo_free(__kfifo); \
+})
- __KFIFO_PUT(fifo, 0, n, 0);
+/**
+ * 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; \
+})
- if (--recsize)
- __KFIFO_PUT(fifo, 1, n, 8);
-#undef __KFIFO_PUT
-}
+/**
+ * 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_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);
+/**
+ * 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; \
+}) \
+)
-extern unsigned int __kfifo_in_generic(struct kfifo *fifo,
- const void *from, unsigned int n, unsigned int recsize);
+/**
+ * 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; \
+}) \
+)
-static inline unsigned int __kfifo_in_rec(struct kfifo *fifo,
- const void *from, unsigned int n, unsigned int recsize)
-{
- unsigned int 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); \
+})
- ret = __kfifo_in_n(fifo, from, n, recsize);
+/**
+ * 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)
- if (likely(ret == 0)) {
- if (recsize)
- __kfifo_poke_n(fifo, recsize, n);
- __kfifo_add_in(fifo, n + recsize);
- }
- return ret;
-}
+/**
+ * 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_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
+ * 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 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.
+ * 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 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);
-}
+ * 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_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);
+/**
+ * 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); \
+})
-extern unsigned int __kfifo_out_generic(struct kfifo *fifo,
- void *to, unsigned int n,
- unsigned int recsize, unsigned int *total);
+/**
+ * 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); \
+})
-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;
- }
+/**
+ * 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); \
+})
- return __kfifo_out_n(fifo, to, l, recsize);
-}
+/**
+ * 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_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
+ * 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 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.
+ * 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 functions.
+ * writer, you don't need extra locking to use these macro.
*/
-static inline __must_check unsigned int kfifo_out_rec(struct kfifo *fifo,
- void *to, unsigned int n, unsigned int recsize,
- unsigned int *total)
+#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); \
+}) \
+)
-{
- if (!__builtin_constant_p(recsize))
- return __kfifo_out_generic(fifo, to, n, recsize, total);
- return __kfifo_out_rec(fifo, to, n, recsize, total);
-}
+extern int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,
+ size_t esize, gfp_t gfp_mask);
-/*
- * __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 void __kfifo_free(struct __kfifo *fifo);
-extern unsigned int __kfifo_from_user_generic(struct kfifo *fifo,
- const void __user *from, unsigned int n, unsigned int recsize);
+extern int __kfifo_init(struct __kfifo *fifo, void *buffer,
+ unsigned int size, size_t esize);
-static inline unsigned int __kfifo_from_user_rec(struct kfifo *fifo,
- const void __user *from, unsigned int n, unsigned int recsize)
-{
- unsigned int ret;
+extern unsigned int __kfifo_in(struct __kfifo *fifo,
+ const void *buf, unsigned int len);
- ret = __kfifo_from_user_n(fifo, from, n, recsize);
+extern unsigned int __kfifo_out(struct __kfifo *fifo,
+ void *buf, unsigned int len);
- if (likely(ret == 0)) {
- if (recsize)
- __kfifo_poke_n(fifo, recsize, n);
- __kfifo_add_in(fifo, n + recsize);
- }
- return ret;
-}
+extern int __kfifo_from_user(struct __kfifo *fifo,
+ const void __user *from, unsigned long len, unsigned int *copied);
-/**
- * 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);
-}
+extern int __kfifo_to_user(struct __kfifo *fifo,
+ void __user *to, unsigned long len, unsigned int *copied);
-/*
- * __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_dma_in_prepare(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len);
-extern unsigned int __kfifo_to_user_generic(struct kfifo *fifo,
- void __user *to, unsigned int n, unsigned int recsize,
- unsigned int *total);
+extern unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len);
-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;
- }
+extern unsigned int __kfifo_out_peek(struct __kfifo *fifo,
+ void *buf, unsigned int len);
- return __kfifo_to_user_n(fifo, to, n, l, recsize);
-}
+extern unsigned int __kfifo_in_r(struct __kfifo *fifo,
+ const void *buf, unsigned int len, size_t 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);
-}
+extern unsigned int __kfifo_out_r(struct __kfifo *fifo,
+ void *buf, unsigned int len, size_t recsize);
-/*
- * __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);
+extern int __kfifo_from_user_r(struct __kfifo *fifo,
+ const void __user *from, unsigned long len, unsigned int *copied,
+ size_t 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);
-}
+extern int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to,
+ unsigned long len, unsigned int *copied, size_t 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);
+extern unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len, size_t recsize);
-static inline void __kfifo_skip_rec(struct kfifo *fifo,
- unsigned int recsize)
-{
- unsigned int l;
+extern void __kfifo_dma_in_finish_r(struct __kfifo *fifo,
+ unsigned int len, size_t recsize);
- if (recsize) {
- l = __kfifo_peek_n(fifo, recsize);
+extern unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len, size_t recsize);
- if (l + recsize <= kfifo_len(fifo)) {
- __kfifo_add_out(fifo, l + recsize);
- return;
- }
- }
- kfifo_reset_out(fifo);
-}
+extern void __kfifo_dma_out_finish_r(struct __kfifo *fifo, size_t recsize);
-/**
- * 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);
-}
+extern unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t 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);
+extern unsigned int __kfifo_out_peek_r(struct __kfifo *fifo,
+ void *buf, unsigned int len, size_t recsize);
- return (l > recsize) ? l - recsize : 0;
-}
+extern unsigned int __kfifo_max_r(unsigned int len, size_t recsize);
#endif
+++ /dev/null
-/*
- * 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);
/*
- * A generic kernel FIFO implementation.
+ * A generic kernel FIFO implementation
*
- * Copyright (C) 2009 Stefani Seibold <stefani@seibold.net>
- * Copyright (C) 2004 Stelian Pop <stelian@popies.net>
+ * 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
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/err.h>
-#include <linux/kfifo.h>
#include <linux/log2.h>
#include <linux/uaccess.h>
+#include <linux/kfifo.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.
- *
+/*
+ * internal helper to calculate the unused elements in a fifo
*/
-void kfifo_init(struct kfifo *fifo, void *buffer, unsigned int size)
+static inline unsigned int kfifo_unused(struct __kfifo *fifo)
{
- /* size must be a power of 2 */
- BUG_ON(!is_power_of_2(size));
-
- _kfifo_init(fifo, buffer, size);
+ return (fifo->mask + 1) - (fifo->in - fifo->out);
}
-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)
+int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,
+ size_t esize, gfp_t gfp_mask)
{
- unsigned char *buffer;
-
/*
- * round up to the next power of 2, since our 'let the indices
+ * 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)) {
- BUG_ON(size > 0x80000000);
- size = roundup_pow_of_two(size);
+ 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;
}
- buffer = kmalloc(size, gfp_mask);
- if (!buffer) {
- _kfifo_init(fifo, NULL, 0);
+ fifo->data = kmalloc(size * esize, gfp_mask);
+
+ if (!fifo->data) {
+ fifo->mask = 0;
return -ENOMEM;
}
-
- _kfifo_init(fifo, buffer, size);
+ fifo->mask = size - 1;
return 0;
}
-EXPORT_SYMBOL(kfifo_alloc);
+EXPORT_SYMBOL(__kfifo_alloc);
-/**
- * kfifo_free - frees the FIFO internal buffer
- * @fifo: the fifo to be freed.
- */
-void kfifo_free(struct kfifo *fifo)
+void __kfifo_free(struct __kfifo *fifo)
{
- kfree(fifo->buffer);
- _kfifo_init(fifo, NULL, 0);
+ kfree(fifo->data);
+ fifo->in = 0;
+ fifo->out = 0;
+ fifo->esize = 0;
+ fifo->data = NULL;
+ fifo->mask = 0;
}
-EXPORT_SYMBOL(kfifo_free);
+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)
+int __kfifo_init(struct __kfifo *fifo, void *buffer,
+ unsigned int size, size_t esize)
{
- if (len < kfifo_len(fifo)) {
- __kfifo_add_out(fifo, len);
- return;
+ 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;
}
- kfifo_reset_out(fifo);
+ fifo->mask = size - 1;
+
+ return 0;
}
-EXPORT_SYMBOL(kfifo_skip);
+EXPORT_SYMBOL(__kfifo_init);
-static inline void __kfifo_in_data(struct kfifo *fifo,
- const void *from, unsigned int len, unsigned int off)
+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);
/*
- * Ensure that we sample the fifo->out index -before- we
- * start putting bytes into the kfifo.
+ * make sure that the data in the fifo is up to date before
+ * incrementing the fifo->in index counter
*/
+ smp_wmb();
+}
- smp_mb();
-
- off = __kfifo_off(fifo, fifo->in + off);
+unsigned int __kfifo_in(struct __kfifo *fifo,
+ const void *buf, unsigned int len)
+{
+ unsigned int l;
- /* first put the data starting from fifo->in to buffer end */
- l = min(len, fifo->size - off);
- memcpy(fifo->buffer + off, from, l);
+ l = kfifo_unused(fifo);
+ if (len > l)
+ len = l;
- /* then put the rest (if any) at the beginning of the buffer */
- memcpy(fifo->buffer, from + l, len - l);
+ kfifo_copy_in(fifo, buf, len, fifo->in);
+ fifo->in += len;
+ return len;
}
+EXPORT_SYMBOL(__kfifo_in);
-static inline void __kfifo_out_data(struct kfifo *fifo,
- void *to, unsigned int len, unsigned int off)
+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);
/*
- * Ensure that we sample the fifo->in index -before- we
- * start removing bytes from the kfifo.
+ * make sure that the data is copied before
+ * incrementing the fifo->out index counter
*/
+ smp_wmb();
+}
- smp_rmb();
+unsigned int __kfifo_out_peek(struct __kfifo *fifo,
+ void *buf, unsigned int len)
+{
+ unsigned int l;
- off = __kfifo_off(fifo, fifo->out + off);
+ l = fifo->in - fifo->out;
+ if (len > l)
+ len = l;
- /* 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);
+ kfifo_copy_out(fifo, buf, len, fifo->out);
+ return len;
+}
+EXPORT_SYMBOL(__kfifo_out_peek);
- /* then get the rest (if any) from the beginning of the buffer */
- memcpy(to + l, fifo->buffer, len - l);
+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 inline int __kfifo_from_user_data(struct kfifo *fifo,
- const void __user *from, unsigned int len, unsigned int off,
- unsigned *lenout)
+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;
- int ret;
+ 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);
+ }
/*
- * Ensure that we sample the fifo->out index -before- we
- * start putting bytes into the kfifo.
+ * 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;
+}
- smp_mb();
+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;
- off = __kfifo_off(fifo, fifo->in + off);
+ if (esize != 1)
+ len /= esize;
- /* 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;
+ l = kfifo_unused(fifo);
+ if (len > l)
+ len = 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;
+ 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 inline int __kfifo_to_user_data(struct kfifo *fifo,
- void __user *to, unsigned int len, unsigned int off, unsigned *lenout)
+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;
- int ret;
-
+ 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);
+ }
/*
- * Ensure that we sample the fifo->in index -before- we
- * start removing bytes from the kfifo.
+ * 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;
+}
- smp_rmb();
+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;
- off = __kfifo_off(fifo, fifo->out + off);
+ if (esize != 1)
+ len /= esize;
- /* 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;
+ l = fifo->in - fifo->out;
+ if (len > l)
+ len = l;
+ ret = kfifo_copy_to_user(fifo, to, len, fifo->out, copied);
if (unlikely(ret)) {
- *lenout -= ret;
- return -EFAULT;
- }
+ len -= ret;
+ err = -EFAULT;
+ } else
+ err = 0;
+ fifo->out += len;
+ return err;
+}
+EXPORT_SYMBOL(__kfifo_to_user);
- /* 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;
+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;
+ }
}
- *lenout += len;
- return 0;
+ sgl->page_link = 0;
+ sg_set_page(sgl++, page, len, off);
+ return n + 1;
}
-unsigned int __kfifo_in_n(struct kfifo *fifo,
- const void *from, unsigned int len, unsigned int recsize)
+static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl,
+ int nents, unsigned int len, unsigned int off)
{
- if (kfifo_avail(fifo) < len + recsize)
- return len + 1;
+ unsigned int size = fifo->mask + 1;
+ unsigned int esize = fifo->esize;
+ unsigned int l;
+ unsigned int n;
- __kfifo_in_data(fifo, from, len, recsize);
- return 0;
+ 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;
}
-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)
+unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len)
{
- len = min(kfifo_avail(fifo), len);
+ unsigned int l;
- __kfifo_in_data(fifo, from, len, 0);
- __kfifo_add_in(fifo, len);
- return len;
+ l = kfifo_unused(fifo);
+ if (len > l)
+ len = l;
+
+ return setup_sgl(fifo, sgl, nents, len, fifo->in);
}
-EXPORT_SYMBOL(kfifo_in);
+EXPORT_SYMBOL(__kfifo_dma_in_prepare);
-unsigned int __kfifo_in_generic(struct kfifo *fifo,
- const void *from, unsigned int len, unsigned int recsize)
+unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len)
{
- return __kfifo_in_rec(fifo, from, len, recsize);
+ 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_in_generic);
+EXPORT_SYMBOL(__kfifo_dma_out_prepare);
-unsigned int __kfifo_out_n(struct kfifo *fifo,
- void *to, unsigned int len, unsigned int recsize)
+unsigned int __kfifo_max_r(unsigned int len, size_t recsize)
{
- if (kfifo_len(fifo) < len + recsize)
- return len;
+ unsigned int max = (1 << (recsize << 3)) - 1;
- __kfifo_out_data(fifo, to, len, recsize);
- __kfifo_add_out(fifo, len + recsize);
- return 0;
+ if (len > max)
+ return max;
+ return len;
}
-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.
+#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
*/
-unsigned int kfifo_out(struct kfifo *fifo, void *to, unsigned int len)
+static unsigned int __kfifo_peek_n(struct __kfifo *fifo, size_t recsize)
{
- len = min(kfifo_len(fifo), len);
+ unsigned int l;
+ unsigned int mask = fifo->mask;
+ unsigned char *data = fifo->data;
- __kfifo_out_data(fifo, to, len, 0);
- __kfifo_add_out(fifo, len);
+ l = __KFIFO_PEEK(data, fifo->out, mask);
- return len;
+ if (--recsize)
+ l |= __KFIFO_PEEK(data, fifo->out + 1, mask) << 8;
+
+ return l;
}
-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.
+
+#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
*/
-unsigned int kfifo_out_peek(struct kfifo *fifo, void *to, unsigned int len,
- unsigned offset)
+static void __kfifo_poke_n(struct __kfifo *fifo, unsigned int n, size_t recsize)
{
- len = min(kfifo_len(fifo), len + offset);
+ unsigned int mask = fifo->mask;
+ unsigned char *data = fifo->data;
- __kfifo_out_data(fifo, to, len, offset);
- return len;
+ __KFIFO_POKE(data, fifo->in, mask, n);
+
+ if (recsize > 1)
+ __KFIFO_POKE(data, fifo->in + 1, mask, n >> 8);
}
-EXPORT_SYMBOL(kfifo_out_peek);
-unsigned int __kfifo_out_generic(struct kfifo *fifo,
- void *to, unsigned int len, unsigned int recsize,
- unsigned int *total)
+unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize)
{
- return __kfifo_out_rec(fifo, to, len, recsize, total);
+ return __kfifo_peek_n(fifo, recsize);
}
-EXPORT_SYMBOL(__kfifo_out_generic);
+EXPORT_SYMBOL(__kfifo_len_r);
-unsigned int __kfifo_from_user_n(struct kfifo *fifo,
- const void __user *from, unsigned int len, unsigned int recsize)
+unsigned int __kfifo_in_r(struct __kfifo *fifo, const void *buf,
+ unsigned int len, size_t recsize)
{
- unsigned total;
+ if (len + recsize > kfifo_unused(fifo))
+ return 0;
- if (kfifo_avail(fifo) < len + recsize)
- return len + 1;
+ __kfifo_poke_n(fifo, len, recsize);
- __kfifo_from_user_data(fifo, from, len, recsize, &total);
- return total;
+ kfifo_copy_in(fifo, buf, len, fifo->in + recsize);
+ fifo->in += len + recsize;
+ return len;
}
-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)
+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)
{
- 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;
+ *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_from_user);
+EXPORT_SYMBOL(__kfifo_out_peek_r);
-unsigned int __kfifo_from_user_generic(struct kfifo *fifo,
- const void __user *from, unsigned int len, unsigned int recsize)
+unsigned int __kfifo_out_r(struct __kfifo *fifo, void *buf,
+ unsigned int len, size_t recsize)
{
- return __kfifo_from_user_rec(fifo, from, len, 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_from_user_generic);
+EXPORT_SYMBOL(__kfifo_out_r);
-unsigned int __kfifo_to_user_n(struct kfifo *fifo,
- void __user *to, unsigned int len, unsigned int reclen,
- unsigned int recsize)
+int __kfifo_from_user_r(struct __kfifo *fifo, const void __user *from,
+ unsigned long len, unsigned int *copied, size_t recsize)
{
- unsigned int ret, total;
+ unsigned long ret;
- if (kfifo_len(fifo) < reclen + recsize)
- return len;
+ len = __kfifo_max_r(len, recsize);
- ret = __kfifo_to_user_data(fifo, to, reclen, recsize, &total);
+ if (len + recsize > kfifo_unused(fifo)) {
+ *copied = 0;
+ return 0;
+ }
- if (likely(ret == 0))
- __kfifo_add_out(fifo, reclen + recsize);
+ __kfifo_poke_n(fifo, len, recsize);
- return total;
+ 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_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)
+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)
{
- 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;
+ 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);
+EXPORT_SYMBOL(__kfifo_to_user_r);
-unsigned int __kfifo_to_user_generic(struct kfifo *fifo,
- void __user *to, unsigned int len, unsigned int recsize,
- unsigned int *total)
+unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)
{
- return __kfifo_to_user_rec(fifo, to, len, recsize, total);
+ 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_to_user_generic);
+EXPORT_SYMBOL(__kfifo_dma_in_prepare_r);
-unsigned int __kfifo_peek_generic(struct kfifo *fifo, unsigned int recsize)
+void __kfifo_dma_in_finish_r(struct __kfifo *fifo,
+ unsigned int len, size_t recsize)
{
- if (recsize == 0)
- return kfifo_avail(fifo);
-
- return __kfifo_peek_n(fifo, recsize);
+ len = __kfifo_max_r(len, recsize);
+ __kfifo_poke_n(fifo, len, recsize);
+ fifo->in += len + recsize;
}
-EXPORT_SYMBOL(__kfifo_peek_generic);
+EXPORT_SYMBOL(__kfifo_dma_in_finish_r);
-void __kfifo_skip_generic(struct kfifo *fifo, unsigned int recsize)
+unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)
{
- __kfifo_skip_rec(fifo, 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_skip_generic);
+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);
projects / GitHub / LineageOS / android_kernel_samsung_universal7580.git / commitdiff