[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 <scsi/sg.h>		/* for struct sg_iovec */

#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,
			     struct rq_map_data *map_data, void __user *ubuf,
			     unsigned int len, gfp_t gfp_mask)
{
	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 (blk_rq_aligned(q, ubuf, len) && !map_data)
		bio = bio_map_user(q, NULL, uaddr, len, reading, gfp_mask);
	else
		bio = bio_copy_user(q, map_data, uaddr, len, reading, gfp_mask);

	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_TYPE_BLOCK_PC usage
 * @q:		request queue where request should be inserted
 * @rq:		request structure to fill
 * @map_data:   pointer to the rq_map_data holding pages (if necessary)
 * @ubuf:	the user buffer
 * @len:	length of user data
 * @gfp_mask:	memory allocation flags
 *
 * Description:
 *    Data will be mapped directly for zero copy I/O, if possible. Otherwise
 *    a kernel bounce buffer is used.
 *
 *    A matching blk_rq_unmap_user() must be issued at the end of I/O, 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,
		    struct rq_map_data *map_data, void __user *ubuf,
		    unsigned long len, gfp_t gfp_mask)
{
	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, map_data, ubuf, map_len,
					gfp_mask);
		if (ret < 0)
			goto unmap_rq;
		if (!bio)
			bio = rq->bio;
		bytes_read += ret;
		ubuf += ret;
	}

	if (!bio_flagged(bio, BIO_USER_MAPPED))
		rq->cmd_flags |= REQ_COPY_USER;

	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_TYPE_BLOCK_PC usage
 * @q:		request queue where request should be inserted
 * @rq:		request to map data to
 * @map_data:   pointer to the rq_map_data holding pages (if necessary)
 * @iov:	pointer to the iovec
 * @iov_count:	number of elements in the iovec
 * @len:	I/O byte count
 * @gfp_mask:	memory allocation flags
 *
 * Description:
 *    Data will be mapped directly for zero copy I/O, if possible. Otherwise
 *    a kernel bounce buffer is used.
 *
 *    A matching blk_rq_unmap_user() must be issued at the end of I/O, 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 rq_map_data *map_data, struct sg_iovec *iov,
			int iov_count, unsigned int len, gfp_t gfp_mask)
{
	struct bio *bio;
	int i, read = rq_data_dir(rq) == READ;
	int unaligned = 0;

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

	for (i = 0; i < iov_count; i++) {
		unsigned long uaddr = (unsigned long)iov[i].iov_base;

		if (uaddr & queue_dma_alignment(q)) {
			unaligned = 1;
			break;
		}
	}

	if (unaligned || (q->dma_pad_mask & len) || map_data)
		bio = bio_copy_user_iov(q, map_data, iov, iov_count, read,
					gfp_mask);
	else
		bio = bio_map_user_iov(q, NULL, iov, iov_count, read, gfp_mask);

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

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

	if (!bio_flagged(bio, BIO_USER_MAPPED))
		rq->cmd_flags |= REQ_COPY_USER;

	blk_queue_bounce(q, &bio);
	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 I/O 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_TYPE_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
 *
 * Description:
 *    Data will be mapped directly if possible. Otherwise a bounce
 *    buffer is used.
 */
int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
		    unsigned int len, gfp_t gfp_mask)
{
	int reading = rq_data_dir(rq) == READ;
	int do_copy = 0;
	struct bio *bio;

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

	do_copy = !blk_rq_aligned(q, kbuf, len) || object_is_on_stack(kbuf);
	if (do_copy)
		bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
	else
		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);

	if (do_copy)
		rq->cmd_flags |= REQ_COPY_USER;

	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>
afdc1a78	8	#include <scsi/sg.h> /* for struct sg_iovec */
86db1e29 JA	9
	10	#include "blk.h"
	11
	12	int blk_rq_append_bio(struct request_queue q, struct request rq,
	13	struct bio *bio)
	14	{
	15	if (!rq->bio)
	16	blk_rq_bio_prep(q, rq, bio);
	17	else if (!ll_back_merge_fn(q, rq, bio))
	18	return -EINVAL;
	19	else {
	20	rq->biotail->bi_next = bio;
	21	rq->biotail = bio;
	22
	23	rq->data_len += bio->bi_size;
	24	}
	25	return 0;
	26	}
	27	EXPORT_SYMBOL(blk_rq_append_bio);
	28
	29	static int __blk_rq_unmap_user(struct bio *bio)
	30	{
	31	int ret = 0;
	32
	33	if (bio) {
	34	if (bio_flagged(bio, BIO_USER_MAPPED))
	35	bio_unmap_user(bio);
	36	else
	37	ret = bio_uncopy_user(bio);
	38	}
	39
	40	return ret;
	41	}
	42
	43	static int __blk_rq_map_user(struct request_queue q, struct request rq,
152e283f FT	44	struct rq_map_data map_data, void __user ubuf,
152e283f FT	45	unsigned int len, gfp_t gfp_mask)
86db1e29 JA	46	{
	47	unsigned long uaddr;
	48	struct bio bio, orig_bio;
	49	int reading, ret;
	50
	51	reading = rq_data_dir(rq) == READ;
	52
	53	/*
	54	* if alignment requirement is satisfied, map in user pages for
	55	* direct dma. else, set up kernel bounce buffers
	56	*/
	57	uaddr = (unsigned long) ubuf;
87904074	58	if (blk_rq_aligned(q, ubuf, len) && !map_data)
a3bce90e	59	bio = bio_map_user(q, NULL, uaddr, len, reading, gfp_mask);
86db1e29	60	else
152e283f	61	bio = bio_copy_user(q, map_data, uaddr, len, reading, gfp_mask);
86db1e29 JA	62
	63	if (IS_ERR(bio))
	64	return PTR_ERR(bio);
	65
	66	orig_bio = bio;
	67	blk_queue_bounce(q, &bio);
	68
	69	/*
	70	* We link the bounce buffer in and could have to traverse it
	71	* later so we have to get a ref to prevent it from being freed
	72	*/
	73	bio_get(bio);
	74
	75	ret = blk_rq_append_bio(q, rq, bio);
	76	if (!ret)
	77	return bio->bi_size;
	78
	79	/* if it was boucned we must call the end io function */
	80	bio_endio(bio, 0);
	81	__blk_rq_unmap_user(orig_bio);
	82	bio_put(bio);
	83	return ret;
	84	}
	85
	86	/**
710027a4	87	* blk_rq_map_user - map user data to a request, for REQ_TYPE_BLOCK_PC usage
86db1e29 JA	88	* @q: request queue where request should be inserted
86db1e29 JA	89	* @rq: request structure to fill
152e283f	90	* @map_data: pointer to the rq_map_data holding pages (if necessary)
86db1e29 JA	91	* @ubuf: the user buffer
86db1e29 JA	92	* @len: length of user data
a3bce90e	93	* @gfp_mask: memory allocation flags
86db1e29 JA	94	*
86db1e29 JA	95	* Description:
710027a4	96	* Data will be mapped directly for zero copy I/O, if possible. Otherwise
86db1e29 JA	97	* a kernel bounce buffer is used.
86db1e29 JA	98	*
710027a4	99	* A matching blk_rq_unmap_user() must be issued at the end of I/O, while
86db1e29 JA	100	* still in process context.
	101	*
	102	* Note: The mapped bio may need to be bounced through blk_queue_bounce()
	103	* before being submitted to the device, as pages mapped may be out of
	104	* reach. It's the callers responsibility to make sure this happens. The
	105	* original bio must be passed back in to blk_rq_unmap_user() for proper
	106	* unmapping.
	107	*/
	108	int blk_rq_map_user(struct request_queue q, struct request rq,
152e283f FT	109	struct rq_map_data map_data, void __user ubuf,
152e283f FT	110	unsigned long len, gfp_t gfp_mask)
86db1e29 JA	111	{
	112	unsigned long bytes_read = 0;
	113	struct bio *bio = NULL;
	114	int ret;
	115
	116	if (len > (q->max_hw_sectors << 9))
	117	return -EINVAL;
	118	if (!len \|\| !ubuf)
	119	return -EINVAL;
	120
	121	while (bytes_read != len) {
	122	unsigned long map_len, end, start;
	123
	124	map_len = min_t(unsigned long, len - bytes_read, BIO_MAX_SIZE);
	125	end = ((unsigned long)ubuf + map_len + PAGE_SIZE - 1)
	126	>> PAGE_SHIFT;
	127	start = (unsigned long)ubuf >> PAGE_SHIFT;
	128
	129	/*
	130	* A bad offset could cause us to require BIO_MAX_PAGES + 1
	131	* pages. If this happens we just lower the requested
	132	* mapping len by a page so that we can fit
	133	*/
	134	if (end - start > BIO_MAX_PAGES)
	135	map_len -= PAGE_SIZE;
	136
152e283f FT	137	ret = __blk_rq_map_user(q, rq, map_data, ubuf, map_len,
152e283f FT	138	gfp_mask);
86db1e29 JA	139	if (ret < 0)
	140	goto unmap_rq;
	141	if (!bio)
	142	bio = rq->bio;
	143	bytes_read += ret;
	144	ubuf += ret;
	145	}
	146
f18573ab FT	147	if (!bio_flagged(bio, BIO_USER_MAPPED))
f18573ab FT	148	rq->cmd_flags \|= REQ_COPY_USER;
40b01b9b	149
86db1e29 JA	150	rq->buffer = rq->data = NULL;
	151	return 0;
	152	unmap_rq:
	153	blk_rq_unmap_user(bio);
84e9e03c	154	rq->bio = NULL;
86db1e29 JA	155	return ret;
86db1e29 JA	156	}
86db1e29 JA	157	EXPORT_SYMBOL(blk_rq_map_user);
	158
	159	/**
710027a4	160	* blk_rq_map_user_iov - map user data to a request, for REQ_TYPE_BLOCK_PC usage
86db1e29 JA	161	* @q: request queue where request should be inserted
86db1e29 JA	162	* @rq: request to map data to
152e283f	163	* @map_data: pointer to the rq_map_data holding pages (if necessary)
86db1e29 JA	164	* @iov: pointer to the iovec
	165	* @iov_count: number of elements in the iovec
	166	* @len: I/O byte count
a3bce90e	167	* @gfp_mask: memory allocation flags
86db1e29 JA	168	*
86db1e29 JA	169	* Description:
710027a4	170	* Data will be mapped directly for zero copy I/O, if possible. Otherwise
86db1e29 JA	171	* a kernel bounce buffer is used.
86db1e29 JA	172	*
710027a4	173	* A matching blk_rq_unmap_user() must be issued at the end of I/O, while
86db1e29 JA	174	* still in process context.
	175	*
	176	* Note: The mapped bio may need to be bounced through blk_queue_bounce()
	177	* before being submitted to the device, as pages mapped may be out of
	178	* reach. It's the callers responsibility to make sure this happens. The
	179	* original bio must be passed back in to blk_rq_unmap_user() for proper
	180	* unmapping.
	181	*/
	182	int blk_rq_map_user_iov(struct request_queue q, struct request rq,
152e283f FT	183	struct rq_map_data map_data, struct sg_iovec iov,
152e283f FT	184	int iov_count, unsigned int len, gfp_t gfp_mask)
86db1e29 JA	185	{
86db1e29 JA	186	struct bio *bio;
afdc1a78 FT	187	int i, read = rq_data_dir(rq) == READ;
afdc1a78 FT	188	int unaligned = 0;
86db1e29 JA	189
	190	if (!iov \|\| iov_count <= 0)
	191	return -EINVAL;
	192
afdc1a78 FT	193	for (i = 0; i < iov_count; i++) {
	194	unsigned long uaddr = (unsigned long)iov[i].iov_base;
	195
	196	if (uaddr & queue_dma_alignment(q)) {
	197	unaligned = 1;
	198	break;
	199	}
	200	}
	201
152e283f FT	202	if (unaligned \|\| (q->dma_pad_mask & len) \|\| map_data)
	203	bio = bio_copy_user_iov(q, map_data, iov, iov_count, read,
	204	gfp_mask);
afdc1a78	205	else
a3bce90e	206	bio = bio_map_user_iov(q, NULL, iov, iov_count, read, gfp_mask);
afdc1a78	207
86db1e29 JA	208	if (IS_ERR(bio))
	209	return PTR_ERR(bio);
	210
	211	if (bio->bi_size != len) {
	212	bio_endio(bio, 0);
	213	bio_unmap_user(bio);
	214	return -EINVAL;
	215	}
	216
f18573ab FT	217	if (!bio_flagged(bio, BIO_USER_MAPPED))
	218	rq->cmd_flags \|= REQ_COPY_USER;
	219
07359fc6	220	blk_queue_bounce(q, &bio);
86db1e29 JA	221	bio_get(bio);
	222	blk_rq_bio_prep(q, rq, bio);
	223	rq->buffer = rq->data = NULL;
	224	return 0;
	225	}
152e283f	226	EXPORT_SYMBOL(blk_rq_map_user_iov);
86db1e29 JA	227
	228	/**
	229	* blk_rq_unmap_user - unmap a request with user data
	230	* @bio: start of bio list
	231	*
	232	* Description:
	233	* Unmap a rq previously mapped by blk_rq_map_user(). The caller must
	234	* supply the original rq->bio from the blk_rq_map_user() return, since
710027a4	235	* the I/O completion may have changed rq->bio.
86db1e29 JA	236	*/
	237	int blk_rq_unmap_user(struct bio *bio)
	238	{
	239	struct bio *mapped_bio;
	240	int ret = 0, ret2;
	241
	242	while (bio) {
	243	mapped_bio = bio;
	244	if (unlikely(bio_flagged(bio, BIO_BOUNCED)))
	245	mapped_bio = bio->bi_private;
	246
	247	ret2 = __blk_rq_unmap_user(mapped_bio);
	248	if (ret2 && !ret)
	249	ret = ret2;
	250
	251	mapped_bio = bio;
	252	bio = bio->bi_next;
	253	bio_put(mapped_bio);
	254	}
	255
	256	return ret;
	257	}
86db1e29 JA	258	EXPORT_SYMBOL(blk_rq_unmap_user);
	259
	260	/**
710027a4	261	* blk_rq_map_kern - map kernel data to a request, for REQ_TYPE_BLOCK_PC usage
86db1e29 JA	262	* @q: request queue where request should be inserted
	263	* @rq: request to fill
	264	* @kbuf: the kernel buffer
	265	* @len: length of user data
	266	* @gfp_mask: memory allocation flags
68154e90 FT	267	*
	268	* Description:
	269	* Data will be mapped directly if possible. Otherwise a bounce
	270	* buffer is used.
86db1e29 JA	271	*/
	272	int blk_rq_map_kern(struct request_queue q, struct request rq, void *kbuf,
	273	unsigned int len, gfp_t gfp_mask)
	274	{
68154e90 FT	275	int reading = rq_data_dir(rq) == READ;
68154e90 FT	276	int do_copy = 0;
86db1e29 JA	277	struct bio *bio;
	278
	279	if (len > (q->max_hw_sectors << 9))
	280	return -EINVAL;
	281	if (!len \|\| !kbuf)
	282	return -EINVAL;
	283
87904074	284	do_copy = !blk_rq_aligned(q, kbuf, len) \|\| object_is_on_stack(kbuf);
68154e90 FT	285	if (do_copy)
	286	bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
	287	else
	288	bio = bio_map_kern(q, kbuf, len, gfp_mask);
	289
86db1e29 JA	290	if (IS_ERR(bio))
	291	return PTR_ERR(bio);
	292
	293	if (rq_data_dir(rq) == WRITE)
	294	bio->bi_rw \|= (1 << BIO_RW);
	295
68154e90 FT	296	if (do_copy)
	297	rq->cmd_flags \|= REQ_COPY_USER;
	298
86db1e29 JA	299	blk_rq_bio_prep(q, rq, bio);
	300	blk_queue_bounce(q, &rq->bio);
	301	rq->buffer = rq->data = NULL;
	302	return 0;
	303	}
86db1e29	304	EXPORT_SYMBOL(blk_rq_map_kern);