kfifo: add the new generic kfifo API
Add the new version of the kfifo API files kfifo.c and kfifo.h. Signed-off-by: Stefani Seibold <stefani@seibold.net> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Stefani Seibold
Linus Torvalds
parent
4457d98459
commit
4201d9a8e8
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@ -0,0 +1,844 @@
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/*
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* A generic kernel FIFO implementation
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*
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* Copyright (C) 2009/2010 Stefani Seibold <stefani@seibold.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*/
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#ifndef _LINUX_KFIFO_H
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#define _LINUX_KFIFO_H
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/*
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* How to porting drivers to the new generic FIFO API:
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*
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* - Modify the declaration of the "struct kfifo *" object into a
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* in-place "struct kfifo" object
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* - Init the in-place object with kfifo_alloc() or kfifo_init()
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* Note: The address of the in-place "struct kfifo" object must be
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* passed as the first argument to this functions
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* - Replace the use of __kfifo_put into kfifo_in and __kfifo_get
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* into kfifo_out
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* - Replace the use of kfifo_put into kfifo_in_spinlocked and kfifo_get
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* into kfifo_out_spinlocked
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* Note: the spinlock pointer formerly passed to kfifo_init/kfifo_alloc
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* must be passed now to the kfifo_in_spinlocked and kfifo_out_spinlocked
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* as the last parameter
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* - The formerly __kfifo_* functions are renamed into kfifo_*
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*/
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/*
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* Note about locking : There is no locking required until only * one reader
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* and one writer is using the fifo and no kfifo_reset() will be * called
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* kfifo_reset_out() can be safely used, until it will be only called
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* in the reader thread.
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* For multiple writer and one reader there is only a need to lock the writer.
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* And vice versa for only one writer and multiple reader there is only a need
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* to lock the reader.
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*/
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#include <linux/kernel.h>
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#include <linux/spinlock.h>
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#include <linux/stddef.h>
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#include <linux/scatterlist.h>
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struct __kfifo {
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unsigned int in;
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unsigned int out;
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unsigned int mask;
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unsigned int esize;
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void *data;
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};
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#define __STRUCT_KFIFO_COMMON(datatype, recsize, ptrtype) \
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union { \
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struct __kfifo kfifo; \
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datatype *type; \
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char (*rectype)[recsize]; \
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ptrtype *ptr; \
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const ptrtype *ptr_const; \
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}
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#define __STRUCT_KFIFO(type, size, recsize, ptrtype) \
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{ \
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__STRUCT_KFIFO_COMMON(type, recsize, ptrtype); \
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type buf[((size < 2) || (size & (size - 1))) ? -1 : size]; \
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}
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#define STRUCT_KFIFO(type, size) \
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struct __STRUCT_KFIFO(type, size, 0, type)
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#define __STRUCT_KFIFO_PTR(type, recsize, ptrtype) \
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{ \
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__STRUCT_KFIFO_COMMON(type, recsize, ptrtype); \
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type buf[0]; \
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}
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#define STRUCT_KFIFO_PTR(type) \
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struct __STRUCT_KFIFO_PTR(type, 0, type)
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/*
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* define compatibility "struct kfifo" for dynamic allocated fifos
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*/
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struct kfifo __STRUCT_KFIFO_PTR(unsigned char, 0, void);
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#define STRUCT_KFIFO_REC_1(size) \
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struct __STRUCT_KFIFO(unsigned char, size, 1, void)
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#define STRUCT_KFIFO_REC_2(size) \
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struct __STRUCT_KFIFO(unsigned char, size, 2, void)
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/*
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* define kfifo_rec types
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*/
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struct kfifo_rec_ptr_1 __STRUCT_KFIFO_PTR(unsigned char, 1, void);
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struct kfifo_rec_ptr_2 __STRUCT_KFIFO_PTR(unsigned char, 2, void);
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/*
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* helper macro to distinguish between real in place fifo where the fifo
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* array is a part of the structure and the fifo type where the array is
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* outside of the fifo structure.
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*/
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#define __is_kfifo_ptr(fifo) (sizeof(*fifo) == sizeof(struct __kfifo))
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/**
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* DECLARE_KFIFO_PTR - macro to declare a fifo pointer object
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* @fifo: name of the declared fifo
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* @type: type of the fifo elements
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*/
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#define DECLARE_KFIFO_PTR(fifo, type) STRUCT_KFIFO_PTR(type) fifo
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/**
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* DECLARE_KFIFO - macro to declare a fifo object
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* @fifo: name of the declared fifo
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* @type: type of the fifo elements
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* @size: the number of elements in the fifo, this must be a power of 2
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*/
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#define DECLARE_KFIFO(fifo, type, size) STRUCT_KFIFO(type, size) fifo
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/**
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* INIT_KFIFO - Initialize a fifo declared by DECLARE_KFIFO
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* @fifo: name of the declared fifo datatype
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*/
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#define INIT_KFIFO(fifo) \
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(void)({ \
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typeof(&(fifo)) __tmp = &(fifo); \
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struct __kfifo *__kfifo = &__tmp->kfifo; \
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__kfifo->in = 0; \
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__kfifo->out = 0; \
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__kfifo->mask = __is_kfifo_ptr(__tmp) ? 0 : ARRAY_SIZE(__tmp->buf) - 1;\
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__kfifo->esize = sizeof(*__tmp->buf); \
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__kfifo->data = __is_kfifo_ptr(__tmp) ? NULL : __tmp->buf; \
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})
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/**
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* DEFINE_KFIFO - macro to define and initialize a fifo
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* @fifo: name of the declared fifo datatype
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* @type: type of the fifo elements
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* @size: the number of elements in the fifo, this must be a power of 2
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*
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* Note: the macro can be used for global and local fifo data type variables.
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*/
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#define DEFINE_KFIFO(fifo, type, size) \
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DECLARE_KFIFO(fifo, type, size) = \
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(typeof(fifo)) { \
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{ \
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{ \
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.in = 0, \
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.out = 0, \
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.mask = __is_kfifo_ptr(&(fifo)) ? \
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0 : \
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ARRAY_SIZE((fifo).buf) - 1, \
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.esize = sizeof(*(fifo).buf), \
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.data = __is_kfifo_ptr(&(fifo)) ? \
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NULL : \
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(fifo).buf, \
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} \
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} \
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}
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static inline unsigned int __must_check
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__kfifo_must_check_helper(unsigned int val)
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{
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return val;
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}
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/**
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* kfifo_initialized - Check if the fifo is initialized
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* @fifo: address of the fifo to check
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*
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* Return %true if fifo is initialized, otherwise %false.
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* Assumes the fifo was 0 before.
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*/
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#define kfifo_initialized(fifo) ((fifo)->kfifo.mask)
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/**
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* kfifo_esize - returns the size of the element managed by the fifo
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* @fifo: address of the fifo to be used
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*/
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#define kfifo_esize(fifo) ((fifo)->kfifo.esize)
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/**
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* kfifo_recsize - returns the size of the record length field
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* @fifo: address of the fifo to be used
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*/
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#define kfifo_recsize(fifo) (sizeof(*(fifo)->rectype))
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/**
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* kfifo_size - returns the size of the fifo in elements
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* @fifo: address of the fifo to be used
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*/
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#define kfifo_size(fifo) ((fifo)->kfifo.mask + 1)
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/**
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* kfifo_reset - removes the entire fifo content
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* @fifo: address of the fifo to be used
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*
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* Note: usage of kfifo_reset() is dangerous. It should be only called when the
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* fifo is exclusived locked or when it is secured that no other thread is
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* accessing the fifo.
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*/
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#define kfifo_reset(fifo) \
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(void)({ \
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typeof(fifo + 1) __tmp = (fifo); \
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__tmp->kfifo.in = __tmp->kfifo.out = 0; \
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})
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/**
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* kfifo_reset_out - skip fifo content
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* @fifo: address of the fifo to be used
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*
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* Note: The usage of kfifo_reset_out() is safe until it will be only called
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* from the reader thread and there is only one concurrent reader. Otherwise
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* it is dangerous and must be handled in the same way as kfifo_reset().
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*/
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#define kfifo_reset_out(fifo) \
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(void)({ \
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typeof(fifo + 1) __tmp = (fifo); \
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__tmp->kfifo.out = __tmp->kfifo.in; \
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})
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/**
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* kfifo_len - returns the number of used elements in the fifo
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* @fifo: address of the fifo to be used
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*/
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#define kfifo_len(fifo) \
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({ \
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typeof(fifo + 1) __tmpl = (fifo); \
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__tmpl->kfifo.in - __tmpl->kfifo.out; \
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})
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/**
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* kfifo_is_empty - returns true if the fifo is empty
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* @fifo: address of the fifo to be used
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*/
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#define kfifo_is_empty(fifo) \
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({ \
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typeof(fifo + 1) __tmpq = (fifo); \
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__tmpq->kfifo.in == __tmpq->kfifo.out; \
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})
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/**
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* kfifo_is_full - returns true if the fifo is full
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* @fifo: address of the fifo to be used
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*/
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#define kfifo_is_full(fifo) \
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({ \
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typeof(fifo + 1) __tmpq = (fifo); \
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kfifo_len(__tmpq) > __tmpq->kfifo.mask; \
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})
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/**
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* kfifo_avail - returns the number of unused elements in the fifo
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* @fifo: address of the fifo to be used
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*/
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#define kfifo_avail(fifo) \
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__kfifo_must_check_helper( \
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({ \
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typeof(fifo + 1) __tmpq = (fifo); \
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const size_t __recsize = sizeof(*__tmpq->rectype); \
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unsigned int __avail = kfifo_size(__tmpq) - kfifo_len(__tmpq); \
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(__recsize) ? ((__avail <= __recsize) ? 0 : \
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__kfifo_max_r(__avail - __recsize, __recsize)) : \
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__avail; \
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}) \
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)
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/**
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* kfifo_skip - skip output data
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* @fifo: address of the fifo to be used
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*/
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#define kfifo_skip(fifo) \
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(void)({ \
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typeof(fifo + 1) __tmp = (fifo); \
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const size_t __recsize = sizeof(*__tmp->rectype); \
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struct __kfifo *__kfifo = &__tmp->kfifo; \
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if (__recsize) \
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__kfifo_skip_r(__kfifo, __recsize); \
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else \
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__kfifo->out++; \
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})
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/**
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* kfifo_peek_len - gets the size of the next fifo record
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* @fifo: address of the fifo to be used
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*
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* This function returns the size of the next fifo record in number of bytes.
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*/
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#define kfifo_peek_len(fifo) \
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__kfifo_must_check_helper( \
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({ \
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typeof(fifo + 1) __tmp = (fifo); \
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const size_t __recsize = sizeof(*__tmp->rectype); \
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struct __kfifo *__kfifo = &__tmp->kfifo; \
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(!__recsize) ? kfifo_len(__tmp) * sizeof(*__tmp->type) : \
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__kfifo_len_r(__kfifo, __recsize); \
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}) \
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)
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/**
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* kfifo_alloc - dynamically allocates a new fifo buffer
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* @fifo: pointer to the fifo
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* @size: the number of elements in the fifo, this must be a power of 2
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* @gfp_mask: get_free_pages mask, passed to kmalloc()
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*
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* This macro dynamically allocates a new fifo buffer.
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*
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* The numer of elements will be rounded-up to a power of 2.
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* The fifo will be release with kfifo_free().
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* Return 0 if no error, otherwise an error code.
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*/
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#define kfifo_alloc(fifo, size, gfp_mask) \
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__kfifo_must_check_helper( \
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({ \
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typeof(fifo + 1) __tmp = (fifo); \
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struct __kfifo *__kfifo = &__tmp->kfifo; \
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__is_kfifo_ptr(__tmp) ? \
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__kfifo_alloc(__kfifo, size, sizeof(*__tmp->type), gfp_mask) : \
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-EINVAL; \
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}) \
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)
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/**
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* kfifo_free - frees the fifo
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* @fifo: the fifo to be freed
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*/
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#define kfifo_free(fifo) \
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({ \
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typeof(fifo + 1) __tmp = (fifo); \
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struct __kfifo *__kfifo = &__tmp->kfifo; \
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if (__is_kfifo_ptr(__tmp)) \
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__kfifo_free(__kfifo); \
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})
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/**
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* kfifo_init - initialize a fifo using a preallocated buffer
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* @fifo: the fifo to assign the buffer
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* @buffer: the preallocated buffer to be used
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* @size: the size of the internal buffer, this have to be a power of 2
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*
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* This macro initialize a fifo using a preallocated buffer.
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*
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* The numer of elements will be rounded-up to a power of 2.
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* Return 0 if no error, otherwise an error code.
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*/
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#define kfifo_init(fifo, buffer, size) \
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({ \
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typeof(fifo + 1) __tmp = (fifo); \
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struct __kfifo *__kfifo = &__tmp->kfifo; \
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__is_kfifo_ptr(__tmp) ? \
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__kfifo_init(__kfifo, buffer, size, sizeof(*__tmp->type)) : \
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-EINVAL; \
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})
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/**
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* kfifo_put - put data into the fifo
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* @fifo: address of the fifo to be used
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* @val: the data to be added
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*
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* This macro copies the given value into the fifo.
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* It returns 0 if the fifo was full. Otherwise it returns the number
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* processed elements.
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*
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* Note that with only one concurrent reader and one concurrent
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* writer, you don't need extra locking to use these macro.
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*/
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#define kfifo_put(fifo, val) \
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({ \
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typeof(fifo + 1) __tmp = (fifo); \
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typeof(val + 1) __val = (val); \
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unsigned int __ret; \
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const size_t __recsize = sizeof(*__tmp->rectype); \
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struct __kfifo *__kfifo = &__tmp->kfifo; \
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if (0) { \
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typeof(__tmp->ptr_const) __dummy __attribute__ ((unused)); \
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__dummy = (typeof(__val))NULL; \
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} \
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if (__recsize) \
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__ret = __kfifo_in_r(__kfifo, __val, sizeof(*__val), \
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__recsize); \
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else { \
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__ret = !kfifo_is_full(__tmp); \
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if (__ret) { \
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(__is_kfifo_ptr(__tmp) ? \
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((typeof(__tmp->type))__kfifo->data) : \
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(__tmp->buf) \
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)[__kfifo->in & __tmp->kfifo.mask] = \
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*(typeof(__tmp->type))__val; \
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smp_wmb(); \
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__kfifo->in++; \
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} \
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} \
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__ret; \
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})
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/**
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* kfifo_get - get data from the fifo
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* @fifo: address of the fifo to be used
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* @val: the var where to store the data to be added
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*
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* This macro reads the data from the fifo.
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* It returns 0 if the fifo was empty. Otherwise it returns the number
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* processed elements.
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*
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* Note that with only one concurrent reader and one concurrent
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* writer, you don't need extra locking to use these macro.
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*/
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#define kfifo_get(fifo, val) \
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__kfifo_must_check_helper( \
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({ \
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typeof(fifo + 1) __tmp = (fifo); \
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typeof(val + 1) __val = (val); \
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unsigned int __ret; \
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const size_t __recsize = sizeof(*__tmp->rectype); \
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struct __kfifo *__kfifo = &__tmp->kfifo; \
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if (0) \
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__val = (typeof(__tmp->ptr))0; \
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if (__recsize) \
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__ret = __kfifo_out_r(__kfifo, __val, sizeof(*__val), \
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__recsize); \
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else { \
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__ret = !kfifo_is_empty(__tmp); \
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if (__ret) { \
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*(typeof(__tmp->type))__val = \
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(__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
|
||||
|
|
@ -0,0 +1,602 @@
|
|||
/*
|
||||
* 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);
|
||||
Loading…
Reference in New Issue