diff options
Diffstat (limited to 'include/linux/kfifo.h')
| -rw-r--r-- | include/linux/kfifo.h | 1195 |
1 files changed, 713 insertions, 482 deletions
diff --git a/include/linux/kfifo.h b/include/linux/kfifo.h index 9fad0527344f..4aa95f203f3e 100644 --- a/include/linux/kfifo.h +++ b/include/linux/kfifo.h @@ -1,8 +1,7 @@ /* - * 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 @@ -20,8 +19,11 @@ * */ +#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 @@ -30,586 +32,815 @@ * 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 int 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 int 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 void __kfifo_skip_r(struct __kfifo *fifo, size_t recsize); - return (l > recsize) ? l - recsize : 0; -} +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 |