kfifo: add record handling functions

	return off & (fifo->size - 1);

}

/**

 * __kfifo_peek_n internal helper function for determinate the length of

 * the next record in the fifo

 */

static inline unsigned int __kfifo_peek_n(struct kfifo *fifo,

				unsigned int recsize)

{

#define __KFIFO_GET(fifo, off, shift) \

	((fifo)->buffer[__kfifo_off((fifo), (fifo)->out+(off))] << (shift))

	unsigned int l;

	l = __KFIFO_GET(fifo, 0, 0);

	if (--recsize)

		l |= __KFIFO_GET(fifo, 1, 8);

	return l;

#undef	__KFIFO_GET

}

/**

 * __kfifo_poke_n internal helper function for storing the length of

 * the next record into the fifo

 */

static inline void __kfifo_poke_n(struct kfifo *fifo,

			unsigned int recsize, unsigned int n)

{

#define __KFIFO_PUT(fifo, off, val, shift) \

		( \

		(fifo)->buffer[__kfifo_off((fifo), (fifo)->in+(off))] = \

		(unsigned char)((val) >> (shift)) \

		)

	__KFIFO_PUT(fifo, 0, n, 0);

	if (--recsize)

		__KFIFO_PUT(fifo, 1, n, 8);

#undef	__KFIFO_PUT

}

/**

 * __kfifo_in_... internal functions for put date into the fifo

 * do not call it directly, use kfifo_in_rec() instead

 */

extern unsigned int __kfifo_in_n(struct kfifo *fifo,

	const void *from, unsigned int n, unsigned int recsize);

extern unsigned int __kfifo_in_generic(struct kfifo *fifo,

	const void *from, unsigned int n, unsigned int recsize);

static inline unsigned int __kfifo_in_rec(struct kfifo *fifo,

	const void *from, unsigned int n, unsigned int recsize)

{

	unsigned int ret;

	ret = __kfifo_in_n(fifo, from, n, recsize);

	if (likely(ret == 0)) {

		if (recsize)

			__kfifo_poke_n(fifo, recsize, n);

		__kfifo_add_in(fifo, n + recsize);

	}

	return ret;

}

/**

 * kfifo_in_rec - puts some record data into the FIFO

 * @fifo: the fifo to be used.

 * @from: the data to be added.

 * @n: the length of the data to be added.

 * @recsize: size of record field

 *

 * This function copies @n bytes from the @from into the FIFO and returns

 * the number of bytes which cannot be copied.

 * A returned value greater than the @n value means that the record doesn't

 * fit into the buffer.

 *

 * Note that with only one concurrent reader and one concurrent

 * writer, you don't need extra locking to use these functions.

 */

static inline __must_check unsigned int kfifo_in_rec(struct kfifo *fifo,

	void *from, unsigned int n, unsigned int recsize)

{

	if (!__builtin_constant_p(recsize))

		return __kfifo_in_generic(fifo, from, n, recsize);

	return __kfifo_in_rec(fifo, from, n, recsize);

}

/**

 * __kfifo_out_... internal functions for get date from the fifo

 * do not call it directly, use kfifo_out_rec() instead

 */

extern unsigned int __kfifo_out_n(struct kfifo *fifo,

	void *to, unsigned int reclen, unsigned int recsize);

extern unsigned int __kfifo_out_generic(struct kfifo *fifo,

	void *to, unsigned int n,

	unsigned int recsize, unsigned int *total);

static inline unsigned int __kfifo_out_rec(struct kfifo *fifo,

	void *to, unsigned int n, unsigned int recsize,

	unsigned int *total)

{

	unsigned int l;

	if (!recsize) {

		l = n;

		if (total)

			*total = l;

	} else {

		l = __kfifo_peek_n(fifo, recsize);

		if (total)

			*total = l;

		if (n < l)

			return l;

	}

	return __kfifo_out_n(fifo, to, l, recsize);

}

/**

 * kfifo_out_rec - gets some record data from the FIFO

 * @fifo: the fifo to be used.

 * @to: where the data must be copied.

 * @n: the size of the destination buffer.

 * @recsize: size of record field

 * @total: pointer where the total number of to copied bytes should stored

 *

 * This function copies at most @n bytes from the FIFO to @to and returns the

 * number of bytes which cannot be copied.

 * A returned value greater than the @n value means that the record doesn't

 * fit into the @to buffer.

 *

 * Note that with only one concurrent reader and one concurrent

 * writer, you don't need extra locking to use these functions.

 */

static inline __must_check unsigned int kfifo_out_rec(struct kfifo *fifo,

	void *to, unsigned int n, unsigned int recsize,

	unsigned int *total)

{

	if (!__builtin_constant_p(recsize))

		return __kfifo_out_generic(fifo, to, n, recsize, total);

	return __kfifo_out_rec(fifo, to, n, recsize, total);

}

/**

 * __kfifo_from_user_... internal functions for transfer from user space into

 * the fifo. do not call it directly, use kfifo_from_user_rec() instead

 */

extern unsigned int __kfifo_from_user_n(struct kfifo *fifo,

	const void __user *from, unsigned int n, unsigned int recsize);

extern unsigned int __kfifo_from_user_generic(struct kfifo *fifo,

	const void __user *from, unsigned int n, unsigned int recsize);

static inline unsigned int __kfifo_from_user_rec(struct kfifo *fifo,

	const void __user *from, unsigned int n, unsigned int recsize)

{

	unsigned int ret;

	ret = __kfifo_from_user_n(fifo, from, n, recsize);

	if (likely(ret == 0)) {

		if (recsize)

			__kfifo_poke_n(fifo, recsize, n);

		__kfifo_add_in(fifo, n + recsize);

	}

	return ret;

}

/**

 * kfifo_from_user_rec - puts some data from user space into the FIFO

 * @fifo: the fifo to be used.

 * @from: pointer to the data to be added.

 * @n: the length of the data to be added.

 * @recsize: size of record field

 *

 * This function copies @n bytes from the @from into the

 * FIFO and returns the number of bytes which cannot be copied.

 *

 * If the returned value is equal or less the @n value, the copy_from_user()

 * functions has failed. Otherwise the record doesn't fit into the buffer.

 *

 * Note that with only one concurrent reader and one concurrent

 * writer, you don't need extra locking to use these functions.

 */

static inline __must_check unsigned int kfifo_from_user_rec(struct kfifo *fifo,

	const void __user *from, unsigned int n, unsigned int recsize)

{

	if (!__builtin_constant_p(recsize))

		return __kfifo_from_user_generic(fifo, from, n, recsize);

	return __kfifo_from_user_rec(fifo, from, n, recsize);

}

/**

 * __kfifo_to_user_... internal functions for transfer fifo data into user space

 * do not call it directly, use kfifo_to_user_rec() instead

 */

extern unsigned int __kfifo_to_user_n(struct kfifo *fifo,

	void __user *to, unsigned int n, unsigned int reclen,

	unsigned int recsize);

extern unsigned int __kfifo_to_user_generic(struct kfifo *fifo,

	void __user *to, unsigned int n, unsigned int recsize,

	unsigned int *total);

static inline unsigned int __kfifo_to_user_rec(struct kfifo *fifo,

	void __user *to, unsigned int n,

	unsigned int recsize, unsigned int *total)

{

	unsigned int l;

	if (!recsize) {

		l = n;

		if (total)

			*total = l;

	} else {

		l = __kfifo_peek_n(fifo, recsize);

		if (total)

			*total = l;

		if (n < l)

			return l;

	}

	return __kfifo_to_user_n(fifo, to, n, l, recsize);

}

/**

 * kfifo_to_user_rec - gets data from the FIFO and write it to user space

 * @fifo: the fifo to be used.

 * @to: where the data must be copied.

 * @n: the size of the destination buffer.

 * @recsize: size of record field

 * @total: pointer where the total number of to copied bytes should stored

 *

 * This function copies at most @n bytes from the FIFO to the @to.

 * In case of an error, the function returns the number of bytes which cannot

 * be copied.

 * If the returned value is equal or less the @n value, the copy_to_user()

 * functions has failed. Otherwise the record doesn't fit into the @to buffer.

 *

 * Note that with only one concurrent reader and one concurrent

 * writer, you don't need extra locking to use these functions.

 */

static inline __must_check unsigned int kfifo_to_user_rec(struct kfifo *fifo,

		void __user *to, unsigned int n, unsigned int recsize,

		unsigned int *total)

{

	if (!__builtin_constant_p(recsize))

		return __kfifo_to_user_generic(fifo, to, n, recsize, total);

	return __kfifo_to_user_rec(fifo, to, n, recsize, total);

}

/**

 * __kfifo_peek_... internal functions for peek into the next fifo record

 * do not call it directly, use kfifo_peek_rec() instead

 */

extern unsigned int __kfifo_peek_generic(struct kfifo *fifo,

				unsigned int recsize);

/**

 * kfifo_peek_rec - gets the size of the next FIFO record data

 * @fifo: the fifo to be used.

 * @recsize: size of record field

 *

 * This function returns the size of the next FIFO record in number of bytes

 */

static inline __must_check unsigned int kfifo_peek_rec(struct kfifo *fifo,

	unsigned int recsize)

{

	if (!__builtin_constant_p(recsize))

		return __kfifo_peek_generic(fifo, recsize);

	if (!recsize)

		return kfifo_len(fifo);

	return __kfifo_peek_n(fifo, recsize);

}

/**

 * __kfifo_skip_... internal functions for skip the next fifo record

 * do not call it directly, use kfifo_skip_rec() instead

 */

extern void __kfifo_skip_generic(struct kfifo *fifo, unsigned int recsize);

static inline void __kfifo_skip_rec(struct kfifo *fifo,

	unsigned int recsize)

{

	unsigned int l;

	if (recsize) {

		l = __kfifo_peek_n(fifo, recsize);

		if (l + recsize <= kfifo_len(fifo)) {

			__kfifo_add_out(fifo, l + recsize);

			return;

		}

	}

	kfifo_reset_out(fifo);

}

/**

 * kfifo_skip_rec - skip the next fifo out record

 * @fifo: the fifo to be used.

 * @recsize: size of record field

 *

 * This function skips the next FIFO record

 */

static inline void kfifo_skip_rec(struct kfifo *fifo,

	unsigned int recsize)

{

	if (!__builtin_constant_p(recsize))

		__kfifo_skip_generic(fifo, recsize);

	else

		__kfifo_skip_rec(fifo, recsize);

}

/**

 * kfifo_avail_rec - returns the number of bytes available in a record FIFO

 * @fifo: the fifo to be used.

 * @recsize: size of record field

 */

static inline __must_check unsigned int kfifo_avail_rec(struct kfifo *fifo,

	unsigned int recsize)

{

	unsigned int l = kfifo_size(fifo) - kfifo_len(fifo);

	return (l > recsize) ? l - recsize : 0;

}

#endif

}

EXPORT_SYMBOL(kfifo_skip);

/**

 * kfifo_in - puts some data into the FIFO

 * @fifo: the fifo to be used.

 * @from: the data to be added.

 * @len: the length of the data to be added.

 *

 * This function copies at most @len bytes from the @from buffer into

 * the FIFO depending on the free space, and returns the number of

 * bytes copied.

 *

 * Note that with only one concurrent reader and one concurrent

 * writer, you don't need extra locking to use these functions.

 */

unsigned int kfifo_in(struct kfifo *fifo,

			const unsigned char *from, unsigned int len)

static inline void __kfifo_in_data(struct kfifo *fifo,

		const void *from, unsigned int len, unsigned int off)

{

	unsigned int off;

	unsigned int l;

	len = min(len, fifo->size - fifo->in + fifo->out);

	/*

	 * Ensure that we sample the fifo->out index -before- we

	 * start putting bytes into the kfifo.

	smp_mb();

	off = __kfifo_off(fifo, fifo->in);

	off = __kfifo_off(fifo, fifo->in + off);

	/* first put the data starting from fifo->in to buffer end */

	l = min(len, fifo->size - off);

	/* then put the rest (if any) at the beginning of the buffer */

	memcpy(fifo->buffer, from + l, len - l);

	__kfifo_add_in(fifo, len);

	return len;

}

EXPORT_SYMBOL(kfifo_in);

/**

 * kfifo_out - gets some data from the FIFO

 * @fifo: the fifo to be used.

 * @to: where the data must be copied.

 * @len: the size of the destination buffer.

 *

 * This function copies at most @len bytes from the FIFO into the

 * @to buffer and returns the number of copied bytes.

 *

 * Note that with only one concurrent reader and one concurrent

 * writer, you don't need extra locking to use these functions.

 */

unsigned int kfifo_out(struct kfifo *fifo,

			 unsigned char *to, unsigned int len)

static inline void __kfifo_out_data(struct kfifo *fifo,

		void *to, unsigned int len, unsigned int off)

{

	unsigned int off;

	unsigned int l;

	len = min(len, fifo->in - fifo->out);

	/*

	 * Ensure that we sample the fifo->in index -before- we

	 * start removing bytes from the kfifo.

	smp_rmb();

	off = __kfifo_off(fifo, fifo->out);

	off = __kfifo_off(fifo, fifo->out + off);

	/* first get the data from fifo->out until the end of the buffer */

	l = min(len, fifo->size - off);

	/* then get the rest (if any) from the beginning of the buffer */

	memcpy(to + l, fifo->buffer, len - l);

	__kfifo_add_out(fifo, len);

	return len;

}

EXPORT_SYMBOL(kfifo_out);

/**

 * kfifo_from_user - puts some data from user space into the FIFO

 * @fifo: the fifo to be used.

 * @from: pointer to the data to be added.

 * @len: the length of the data to be added.

 *

 * This function copies at most @len bytes from the @from into the

 * FIFO depending and returns the number of copied bytes.

 *

 * Note that with only one concurrent reader and one concurrent

 * writer, you don't need extra locking to use these functions.

 */

unsigned int kfifo_from_user(struct kfifo *fifo,

	const void __user *from, unsigned int len)

static inline unsigned int __kfifo_from_user_data(struct kfifo *fifo,

	 const void __user *from, unsigned int len, unsigned int off)

{

	unsigned int off;

	unsigned int l;

	int ret;

	len = min(len, fifo->size - fifo->in + fifo->out);

	/*

	 * Ensure that we sample the fifo->out index -before- we

	 * start putting bytes into the kfifo.

	smp_mb();

	off = __kfifo_off(fifo, fifo->in);

	off = __kfifo_off(fifo, fifo->in + off);

	/* first put the data starting from fifo->in to buffer end */

	l = min(len, fifo->size - off);

	ret = copy_from_user(fifo->buffer + off, from, l);

	if (unlikely(ret))

		return l - ret;

		return ret + len - l;

	/* then put the rest (if any) at the beginning of the buffer */

	ret = copy_from_user(fifo->buffer, from + l, len - l);

	return copy_from_user(fifo->buffer, from + l, len - l);

}

static inline unsigned int __kfifo_to_user_data(struct kfifo *fifo,

		void __user *to, unsigned int len, unsigned int off)

{

	unsigned int l;

	int ret;

	/*

	 * Ensure that we sample the fifo->in index -before- we

	 * start removing bytes from the kfifo.

	 */

	smp_rmb();

	off = __kfifo_off(fifo, fifo->out + off);

	/* first get the data from fifo->out until the end of the buffer */

	l = min(len, fifo->size - off);

	ret = copy_to_user(to, fifo->buffer + off, l);

	if (unlikely(ret))

		return len - ret;

		return ret + len - l;

	/* then get the rest (if any) from the beginning of the buffer */

	return copy_to_user(to + l, fifo->buffer, len - l);

}

unsigned int __kfifo_in_n(struct kfifo *fifo,

	const void *from, unsigned int len, unsigned int recsize)

{

	if (kfifo_avail(fifo) < len + recsize)

		return len + 1;

	__kfifo_in_data(fifo, from, len, recsize);

	return 0;

}

EXPORT_SYMBOL(__kfifo_in_n);

/**

 * kfifo_in - puts some data into the FIFO

 * @fifo: the fifo to be used.

 * @from: the data to be added.

 * @len: the length of the data to be added.

 *

 * This function copies at most @len bytes from the @from buffer into

 * the FIFO depending on the free space, and returns the number of

 * bytes copied.

 *

 * Note that with only one concurrent reader and one concurrent

 * writer, you don't need extra locking to use these functions.

 */

unsigned int kfifo_in(struct kfifo *fifo, const unsigned char *from,

				unsigned int len)

{

	len = min(kfifo_avail(fifo), len);

	__kfifo_in_data(fifo, from, len, 0);

	__kfifo_add_in(fifo, len);

	return len;

}

EXPORT_SYMBOL(kfifo_in);

unsigned int __kfifo_in_generic(struct kfifo *fifo,

	const void *from, unsigned int len, unsigned int recsize)

{

	return __kfifo_in_rec(fifo, from, len, recsize);

}

EXPORT_SYMBOL(__kfifo_in_generic);

unsigned int __kfifo_out_n(struct kfifo *fifo,

	void *to, unsigned int len, unsigned int recsize)

{

	if (kfifo_len(fifo) < len + recsize)

		return len;

	__kfifo_out_data(fifo, to, len, recsize);

	__kfifo_add_out(fifo, len + recsize);

	return 0;

}

EXPORT_SYMBOL(kfifo_from_user);

EXPORT_SYMBOL(__kfifo_out_n);

/**

 * kfifo_to_user - gets data from the FIFO and write it to user space

 * kfifo_out - gets some data from the FIFO

 * @fifo: the fifo to be used.

 * @to: where the data must be copied.

 * @len: the size of the destination buffer.

 * Note that with only one concurrent reader and one concurrent

 * writer, you don't need extra locking to use these functions.

 */

unsigned int kfifo_to_user(struct kfifo *fifo,

	void __user *to, unsigned int len)

unsigned int kfifo_out(struct kfifo *fifo, unsigned char *to, unsigned int len)

{

	unsigned int off;

	unsigned int l;

	int ret;

	len = min(kfifo_len(fifo), len);

	len = min(len, fifo->in - fifo->out);

	__kfifo_out_data(fifo, to, len, 0);

	__kfifo_add_out(fifo, len);

	/*

	 * Ensure that we sample the fifo->in index -before- we

	 * start removing bytes from the kfifo.

	return len;

}

EXPORT_SYMBOL(kfifo_out);

unsigned int __kfifo_out_generic(struct kfifo *fifo,

	void *to, unsigned int len, unsigned int recsize,

	unsigned int *total)

{

	return __kfifo_out_rec(fifo, to, len, recsize, total);

}

EXPORT_SYMBOL(__kfifo_out_generic);

unsigned int __kfifo_from_user_n(struct kfifo *fifo,

	const void __user *from, unsigned int len, unsigned int recsize)

{

	if (kfifo_avail(fifo) < len + recsize)

		return len + 1;

	return __kfifo_from_user_data(fifo, from, len, recsize);

}

EXPORT_SYMBOL(__kfifo_from_user_n);

/**

 * kfifo_from_user - puts some data from user space into the FIFO

 * @fifo: the fifo to be used.

 * @from: pointer to the data to be added.

 * @len: the length of the data to be added.

 *

 * This function copies at most @len bytes from the @from into the

 * FIFO depending and returns the number of copied bytes.

 *

 * Note that with only one concurrent reader and one concurrent

 * writer, you don't need extra locking to use these functions.

 */

unsigned int kfifo_from_user(struct kfifo *fifo,

	const void __user *from, unsigned int len)

{

	len = min(kfifo_avail(fifo), len);

	len -= __kfifo_from_user_data(fifo, from, len, 0);

	__kfifo_add_in(fifo, len);

	return len;

}

EXPORT_SYMBOL(kfifo_from_user);

	smp_rmb();

unsigned int __kfifo_from_user_generic(struct kfifo *fifo,

	const void __user *from, unsigned int len, unsigned int recsize)

{

	return __kfifo_from_user_rec(fifo, from, len, recsize);

}

EXPORT_SYMBOL(__kfifo_from_user_generic);

	off = __kfifo_off(fifo, fifo->out);

unsigned int __kfifo_to_user_n(struct kfifo *fifo,

	void __user *to, unsigned int len, unsigned int reclen,

	unsigned int recsize)

{

	unsigned int ret;

	/* first get the data from fifo->out until the end of the buffer */

	l = min(len, fifo->size - off);

	ret = copy_to_user(to, fifo->buffer + off, l);

	if (kfifo_len(fifo) < reclen + recsize)

		return len;

	if (unlikely(ret))

		return l - ret;

	ret = __kfifo_to_user_data(fifo, to, reclen, recsize);

	/* then get the rest (if any) from the beginning of the buffer */

	ret = copy_to_user(to + l, fifo->buffer, len - l);

	if (likely(ret == 0))

		__kfifo_add_out(fifo, reclen + recsize);

	if (unlikely(ret))

		return len - ret;

	return ret;

}

EXPORT_SYMBOL(__kfifo_to_user_n);

/**

 * kfifo_to_user - gets data from the FIFO and write it to user space

 * @fifo: the fifo to be used.

 * @to: where the data must be copied.

 * @len: the size of the destination buffer.

 *

 * This function copies at most @len bytes from the FIFO into the

 * @to buffer and returns the number of copied bytes.

 *

 * Note that with only one concurrent reader and one concurrent

 * writer, you don't need extra locking to use these functions.

 */

unsigned int kfifo_to_user(struct kfifo *fifo,

	void __user *to, unsigned int len)

{

	len = min(kfifo_len(fifo), len);

	len -= __kfifo_to_user_data(fifo, to, len, 0);

	__kfifo_add_out(fifo, len);

	return len;

}

EXPORT_SYMBOL(kfifo_to_user);

unsigned int __kfifo_to_user_generic(struct kfifo *fifo,

	void __user *to, unsigned int len, unsigned int recsize,

	unsigned int *total)

{

	return __kfifo_to_user_rec(fifo, to, len, recsize, total);

}

EXPORT_SYMBOL(__kfifo_to_user_generic);

unsigned int __kfifo_peek_generic(struct kfifo *fifo, unsigned int recsize)

{

	if (recsize == 0)

		return kfifo_avail(fifo);

	return __kfifo_peek_n(fifo, recsize);

}

EXPORT_SYMBOL(__kfifo_peek_generic);