[GitHub/mt8127/android_kernel_alcatel_ttab.git] / block / blk-map.c

/*
 * Functions related to mapping data to requests
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/bio.h>
#include <linux/blkdev.h>

#include "blk.h"

int blk_rq_append_bio(struct request_queue *q, struct request *rq,
		      struct bio *bio)
{
	if (!rq->bio)
		blk_rq_bio_prep(q, rq, bio);
	else if (!ll_back_merge_fn(q, rq, bio))
		return -EINVAL;
	else {
		rq->biotail->bi_next = bio;
		rq->biotail = bio;

		rq->data_len += bio->bi_size;
	}
	return 0;
}
EXPORT_SYMBOL(blk_rq_append_bio);

static int __blk_rq_unmap_user(struct bio *bio)
{
	int ret = 0;

	if (bio) {
		if (bio_flagged(bio, BIO_USER_MAPPED))
			bio_unmap_user(bio);
		else
			ret = bio_uncopy_user(bio);
	}

	return ret;
}

static int __blk_rq_map_user(struct request_queue *q, struct request *rq,
			     void __user *ubuf, unsigned int len)
{
	unsigned long uaddr;
	struct bio *bio, *orig_bio;
	int reading, ret;

	reading = rq_data_dir(rq) == READ;

	/*
	 * if alignment requirement is satisfied, map in user pages for
	 * direct dma. else, set up kernel bounce buffers
	 */
	uaddr = (unsigned long) ubuf;
	if (!(uaddr & queue_dma_alignment(q)) &&
	    !(len & queue_dma_alignment(q)))
		bio = bio_map_user(q, NULL, uaddr, len, reading);
	else
		bio = bio_copy_user(q, uaddr, len, reading);

	if (IS_ERR(bio))
		return PTR_ERR(bio);

	orig_bio = bio;
	blk_queue_bounce(q, &bio);

	/*
	 * We link the bounce buffer in and could have to traverse it
	 * later so we have to get a ref to prevent it from being freed
	 */
	bio_get(bio);

	ret = blk_rq_append_bio(q, rq, bio);
	if (!ret)
		return bio->bi_size;

	/* if it was boucned we must call the end io function */
	bio_endio(bio, 0);
	__blk_rq_unmap_user(orig_bio);
	bio_put(bio);
	return ret;
}

/**
 * blk_rq_map_user - map user data to a request, for REQ_BLOCK_PC usage
 * @q:		request queue where request should be inserted
 * @rq:		request structure to fill
 * @ubuf:	the user buffer
 * @len:	length of user data
 *
 * Description:
 *    Data will be mapped directly for zero copy io, if possible. Otherwise
 *    a kernel bounce buffer is used.
 *
 *    A matching blk_rq_unmap_user() must be issued at the end of io, while
 *    still in process context.
 *
 *    Note: The mapped bio may need to be bounced through blk_queue_bounce()
 *    before being submitted to the device, as pages mapped may be out of
 *    reach. It's the callers responsibility to make sure this happens. The
 *    original bio must be passed back in to blk_rq_unmap_user() for proper
 *    unmapping.
 */
int blk_rq_map_user(struct request_queue *q, struct request *rq,
		    void __user *ubuf, unsigned long len)
{
	unsigned long bytes_read = 0;
	struct bio *bio = NULL;
	int ret;

	if (len > (q->max_hw_sectors << 9))
		return -EINVAL;
	if (!len || !ubuf)
		return -EINVAL;

	while (bytes_read != len) {
		unsigned long map_len, end, start;

		map_len = min_t(unsigned long, len - bytes_read, BIO_MAX_SIZE);
		end = ((unsigned long)ubuf + map_len + PAGE_SIZE - 1)
								>> PAGE_SHIFT;
		start = (unsigned long)ubuf >> PAGE_SHIFT;

		/*
		 * A bad offset could cause us to require BIO_MAX_PAGES + 1
		 * pages. If this happens we just lower the requested
		 * mapping len by a page so that we can fit
		 */
		if (end - start > BIO_MAX_PAGES)
			map_len -= PAGE_SIZE;

		ret = __blk_rq_map_user(q, rq, ubuf, map_len);
		if (ret < 0)
			goto unmap_rq;
		if (!bio)
			bio = rq->bio;
		bytes_read += ret;
		ubuf += ret;
	}

	rq->buffer = rq->data = NULL;
	return 0;
unmap_rq:
	blk_rq_unmap_user(bio);
	rq->bio = NULL;
	return ret;
}
EXPORT_SYMBOL(blk_rq_map_user);

/**
 * blk_rq_map_user_iov - map user data to a request, for REQ_BLOCK_PC usage
 * @q:		request queue where request should be inserted
 * @rq:		request to map data to
 * @iov:	pointer to the iovec
 * @iov_count:	number of elements in the iovec
 * @len:	I/O byte count
 *
 * Description:
 *    Data will be mapped directly for zero copy io, if possible. Otherwise
 *    a kernel bounce buffer is used.
 *
 *    A matching blk_rq_unmap_user() must be issued at the end of io, while
 *    still in process context.
 *
 *    Note: The mapped bio may need to be bounced through blk_queue_bounce()
 *    before being submitted to the device, as pages mapped may be out of
 *    reach. It's the callers responsibility to make sure this happens. The
 *    original bio must be passed back in to blk_rq_unmap_user() for proper
 *    unmapping.
 */
int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
			struct sg_iovec *iov, int iov_count, unsigned int len)
{
	struct bio *bio;

	if (!iov || iov_count <= 0)
		return -EINVAL;

	/* we don't allow misaligned data like bio_map_user() does.  If the
	 * user is using sg, they're expected to know the alignment constraints
	 * and respect them accordingly */
	bio = bio_map_user_iov(q, NULL, iov, iov_count,
				rq_data_dir(rq) == READ);
	if (IS_ERR(bio))
		return PTR_ERR(bio);

	if (bio->bi_size != len) {
		bio_endio(bio, 0);
		bio_unmap_user(bio);
		return -EINVAL;
	}

	bio_get(bio);
	blk_rq_bio_prep(q, rq, bio);
	rq->buffer = rq->data = NULL;
	return 0;
}
EXPORT_SYMBOL(blk_rq_map_user_iov);

/**
 * blk_rq_unmap_user - unmap a request with user data
 * @bio:	       start of bio list
 *
 * Description:
 *    Unmap a rq previously mapped by blk_rq_map_user(). The caller must
 *    supply the original rq->bio from the blk_rq_map_user() return, since
 *    the io completion may have changed rq->bio.
 */
int blk_rq_unmap_user(struct bio *bio)
{
	struct bio *mapped_bio;
	int ret = 0, ret2;

	while (bio) {
		mapped_bio = bio;
		if (unlikely(bio_flagged(bio, BIO_BOUNCED)))
			mapped_bio = bio->bi_private;

		ret2 = __blk_rq_unmap_user(mapped_bio);
		if (ret2 && !ret)
			ret = ret2;

		mapped_bio = bio;
		bio = bio->bi_next;
		bio_put(mapped_bio);
	}

	return ret;
}
EXPORT_SYMBOL(blk_rq_unmap_user);

/**
 * blk_rq_map_kern - map kernel data to a request, for REQ_BLOCK_PC usage
 * @q:		request queue where request should be inserted
 * @rq:		request to fill
 * @kbuf:	the kernel buffer
 * @len:	length of user data
 * @gfp_mask:	memory allocation flags
 */
int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
		    unsigned int len, gfp_t gfp_mask)
{
	struct bio *bio;

	if (len > (q->max_hw_sectors << 9))
		return -EINVAL;
	if (!len || !kbuf)
		return -EINVAL;

	bio = bio_map_kern(q, kbuf, len, gfp_mask);
	if (IS_ERR(bio))
		return PTR_ERR(bio);

	if (rq_data_dir(rq) == WRITE)
		bio->bi_rw |= (1 << BIO_RW);

	blk_rq_bio_prep(q, rq, bio);
	blk_queue_bounce(q, &rq->bio);
	rq->buffer = rq->data = NULL;
	return 0;
}
EXPORT_SYMBOL(blk_rq_map_kern);
Commit	Line	Data
86db1e29 JA	1	/*
	2	* Functions related to mapping data to requests
	3	*/
	4	#include <linux/kernel.h>
	5	#include <linux/module.h>
	6	#include <linux/bio.h>
	7	#include <linux/blkdev.h>
	8
	9	#include "blk.h"
	10
	11	int blk_rq_append_bio(struct request_queue q, struct request rq,
	12	struct bio *bio)
	13	{
	14	if (!rq->bio)
	15	blk_rq_bio_prep(q, rq, bio);
	16	else if (!ll_back_merge_fn(q, rq, bio))
	17	return -EINVAL;
	18	else {
	19	rq->biotail->bi_next = bio;
	20	rq->biotail = bio;
	21
	22	rq->data_len += bio->bi_size;
	23	}
	24	return 0;
	25	}
	26	EXPORT_SYMBOL(blk_rq_append_bio);
	27
	28	static int __blk_rq_unmap_user(struct bio *bio)
	29	{
	30	int ret = 0;
	31
	32	if (bio) {
	33	if (bio_flagged(bio, BIO_USER_MAPPED))
	34	bio_unmap_user(bio);
	35	else
	36	ret = bio_uncopy_user(bio);
	37	}
	38
	39	return ret;
	40	}
	41
	42	static int __blk_rq_map_user(struct request_queue q, struct request rq,
	43	void __user *ubuf, unsigned int len)
	44	{
	45	unsigned long uaddr;
	46	struct bio bio, orig_bio;
	47	int reading, ret;
	48
	49	reading = rq_data_dir(rq) == READ;
	50
	51	/*
	52	* if alignment requirement is satisfied, map in user pages for
	53	* direct dma. else, set up kernel bounce buffers
	54	*/
	55	uaddr = (unsigned long) ubuf;
6728cb0e JA	56	if (!(uaddr & queue_dma_alignment(q)) &&
6728cb0e JA	57	!(len & queue_dma_alignment(q)))
86db1e29 JA	58	bio = bio_map_user(q, NULL, uaddr, len, reading);
	59	else
	60	bio = bio_copy_user(q, uaddr, len, reading);
	61
	62	if (IS_ERR(bio))
	63	return PTR_ERR(bio);
	64
	65	orig_bio = bio;
	66	blk_queue_bounce(q, &bio);
	67
	68	/*
	69	* We link the bounce buffer in and could have to traverse it
	70	* later so we have to get a ref to prevent it from being freed
	71	*/
	72	bio_get(bio);
	73
	74	ret = blk_rq_append_bio(q, rq, bio);
	75	if (!ret)
	76	return bio->bi_size;
	77
	78	/* if it was boucned we must call the end io function */
	79	bio_endio(bio, 0);
	80	__blk_rq_unmap_user(orig_bio);
	81	bio_put(bio);
	82	return ret;
	83	}
	84
	85	/**
	86	* blk_rq_map_user - map user data to a request, for REQ_BLOCK_PC usage
	87	* @q: request queue where request should be inserted
	88	* @rq: request structure to fill
	89	* @ubuf: the user buffer
	90	* @len: length of user data
	91	*
	92	* Description:
	93	* Data will be mapped directly for zero copy io, if possible. Otherwise
	94	* a kernel bounce buffer is used.
	95	*
	96	* A matching blk_rq_unmap_user() must be issued at the end of io, while
	97	* still in process context.
	98	*
	99	* Note: The mapped bio may need to be bounced through blk_queue_bounce()
	100	* before being submitted to the device, as pages mapped may be out of
	101	* reach. It's the callers responsibility to make sure this happens. The
	102	* original bio must be passed back in to blk_rq_unmap_user() for proper
	103	* unmapping.
	104	*/
	105	int blk_rq_map_user(struct request_queue q, struct request rq,
	106	void __user *ubuf, unsigned long len)
	107	{
	108	unsigned long bytes_read = 0;
	109	struct bio *bio = NULL;
	110	int ret;
	111
	112	if (len > (q->max_hw_sectors << 9))
	113	return -EINVAL;
	114	if (!len \|\| !ubuf)
	115	return -EINVAL;
	116
	117	while (bytes_read != len) {
	118	unsigned long map_len, end, start;
	119
	120	map_len = min_t(unsigned long, len - bytes_read, BIO_MAX_SIZE);
	121	end = ((unsigned long)ubuf + map_len + PAGE_SIZE - 1)
122	>> PAGE_SHIFT;
123	start = (unsigned long)ubuf >> PAGE_SHIFT;
124
125	/*
126	* A bad offset could cause us to require BIO_MAX_PAGES + 1
127	* pages. If this happens we just lower the requested
128	* mapping len by a page so that we can fit
129	*/
130	if (end - start > BIO_MAX_PAGES)
131	map_len -= PAGE_SIZE;
132
133	ret = __blk_rq_map_user(q, rq, ubuf, map_len);
134	if (ret < 0)
135	goto unmap_rq;
136	if (!bio)
137	bio = rq->bio;
138	bytes_read += ret;
139	ubuf += ret;
140	}
141
142	rq->buffer = rq->data = NULL;
143	return 0;
144	unmap_rq:
145	blk_rq_unmap_user(bio);
84e9e03c	146	rq->bio = NULL;
86db1e29 JA	147	return ret;
86db1e29 JA	148	}
86db1e29 JA	149	EXPORT_SYMBOL(blk_rq_map_user);
	150
	151	/**
	152	* blk_rq_map_user_iov - map user data to a request, for REQ_BLOCK_PC usage
	153	* @q: request queue where request should be inserted
	154	* @rq: request to map data to
	155	* @iov: pointer to the iovec
	156	* @iov_count: number of elements in the iovec
	157	* @len: I/O byte count
	158	*
	159	* Description:
	160	* Data will be mapped directly for zero copy io, if possible. Otherwise
	161	* a kernel bounce buffer is used.
	162	*
	163	* A matching blk_rq_unmap_user() must be issued at the end of io, while
	164	* still in process context.
	165	*
	166	* Note: The mapped bio may need to be bounced through blk_queue_bounce()
	167	* before being submitted to the device, as pages mapped may be out of
	168	* reach. It's the callers responsibility to make sure this happens. The
	169	* original bio must be passed back in to blk_rq_unmap_user() for proper
	170	* unmapping.
	171	*/
	172	int blk_rq_map_user_iov(struct request_queue q, struct request rq,
	173	struct sg_iovec *iov, int iov_count, unsigned int len)
	174	{
	175	struct bio *bio;
	176
	177	if (!iov \|\| iov_count <= 0)
	178	return -EINVAL;
	179
	180	/* we don't allow misaligned data like bio_map_user() does. If the
	181	* user is using sg, they're expected to know the alignment constraints
	182	* and respect them accordingly */
6728cb0e JA	183	bio = bio_map_user_iov(q, NULL, iov, iov_count,
6728cb0e JA	184	rq_data_dir(rq) == READ);
86db1e29 JA	185	if (IS_ERR(bio))
	186	return PTR_ERR(bio);
	187
	188	if (bio->bi_size != len) {
	189	bio_endio(bio, 0);
	190	bio_unmap_user(bio);
	191	return -EINVAL;
	192	}
	193
	194	bio_get(bio);
	195	blk_rq_bio_prep(q, rq, bio);
	196	rq->buffer = rq->data = NULL;
	197	return 0;
	198	}
86db1e29 JA	199	EXPORT_SYMBOL(blk_rq_map_user_iov);
	200
	201	/**
	202	* blk_rq_unmap_user - unmap a request with user data
	203	* @bio: start of bio list
	204	*
	205	* Description:
	206	* Unmap a rq previously mapped by blk_rq_map_user(). The caller must
	207	* supply the original rq->bio from the blk_rq_map_user() return, since
	208	* the io completion may have changed rq->bio.
	209	*/
	210	int blk_rq_unmap_user(struct bio *bio)
	211	{
	212	struct bio *mapped_bio;
	213	int ret = 0, ret2;
	214
	215	while (bio) {
	216	mapped_bio = bio;
	217	if (unlikely(bio_flagged(bio, BIO_BOUNCED)))
	218	mapped_bio = bio->bi_private;
	219
	220	ret2 = __blk_rq_unmap_user(mapped_bio);
	221	if (ret2 && !ret)
	222	ret = ret2;
	223
	224	mapped_bio = bio;
	225	bio = bio->bi_next;
	226	bio_put(mapped_bio);
	227	}
	228
	229	return ret;
	230	}
86db1e29 JA	231	EXPORT_SYMBOL(blk_rq_unmap_user);
	232
	233	/**
	234	* blk_rq_map_kern - map kernel data to a request, for REQ_BLOCK_PC usage
	235	* @q: request queue where request should be inserted
	236	* @rq: request to fill
	237	* @kbuf: the kernel buffer
	238	* @len: length of user data
	239	* @gfp_mask: memory allocation flags
	240	*/
	241	int blk_rq_map_kern(struct request_queue q, struct request rq, void *kbuf,
	242	unsigned int len, gfp_t gfp_mask)
	243	{
	244	struct bio *bio;
	245
	246	if (len > (q->max_hw_sectors << 9))
	247	return -EINVAL;
	248	if (!len \|\| !kbuf)
	249	return -EINVAL;
	250
	251	bio = bio_map_kern(q, kbuf, len, gfp_mask);
	252	if (IS_ERR(bio))
	253	return PTR_ERR(bio);
	254
	255	if (rq_data_dir(rq) == WRITE)
	256	bio->bi_rw \|= (1 << BIO_RW);
	257
	258	blk_rq_bio_prep(q, rq, bio);
	259	blk_queue_bounce(q, &rq->bio);
	260	rq->buffer = rq->data = NULL;
	261	return 0;
	262	}
86db1e29	263	EXPORT_SYMBOL(blk_rq_map_kern);