[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, int null_mapped, 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);

	if (null_mapped)
		bio->bi_flags |= (1 << BIO_NULL_MAPPED);

	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, null_mapped = 0;

	if (len > (q->max_hw_sectors << 9))
		return -EINVAL;
	if (!len)
		return -EINVAL;
	if (!ubuf) {
		if (!map_data || rq_data_dir(rq) != READ)
			return -EINVAL;
		null_mapped = 1;
	}

	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,
					null_mapped, 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) {
		/*
		 * Grab an extra reference to this bio, as bio_unmap_user()
		 * expects to be able to drop it twice as it happens on the
		 * normal IO completion path
		 */
		bio_get(bio);
		bio_endio(bio, 0);
		__blk_rq_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	44	struct rq_map_data map_data, void __user ubuf,
81882766	45	unsigned int len, int null_mapped, 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
81882766 FT	66	if (null_mapped)
	67	bio->bi_flags \|= (1 << BIO_NULL_MAPPED);
	68
86db1e29 JA	69	orig_bio = bio;
	70	blk_queue_bounce(q, &bio);
	71
	72	/*
	73	* We link the bounce buffer in and could have to traverse it
	74	* later so we have to get a ref to prevent it from being freed
	75	*/
	76	bio_get(bio);
	77
	78	ret = blk_rq_append_bio(q, rq, bio);
	79	if (!ret)
	80	return bio->bi_size;
	81
	82	/* if it was boucned we must call the end io function */
	83	bio_endio(bio, 0);
	84	__blk_rq_unmap_user(orig_bio);
	85	bio_put(bio);
	86	return ret;
	87	}
	88
	89	/**
710027a4	90	* blk_rq_map_user - map user data to a request, for REQ_TYPE_BLOCK_PC usage
86db1e29 JA	91	* @q: request queue where request should be inserted
86db1e29 JA	92	* @rq: request structure to fill
152e283f	93	* @map_data: pointer to the rq_map_data holding pages (if necessary)
86db1e29 JA	94	* @ubuf: the user buffer
86db1e29 JA	95	* @len: length of user data
a3bce90e	96	* @gfp_mask: memory allocation flags
86db1e29 JA	97	*
86db1e29 JA	98	* Description:
710027a4	99	* Data will be mapped directly for zero copy I/O, if possible. Otherwise
86db1e29 JA	100	* a kernel bounce buffer is used.
86db1e29 JA	101	*
710027a4	102	* A matching blk_rq_unmap_user() must be issued at the end of I/O, while
86db1e29 JA	103	* still in process context.
	104	*
	105	* Note: The mapped bio may need to be bounced through blk_queue_bounce()
	106	* before being submitted to the device, as pages mapped may be out of
	107	* reach. It's the callers responsibility to make sure this happens. The
	108	* original bio must be passed back in to blk_rq_unmap_user() for proper
	109	* unmapping.
	110	*/
	111	int blk_rq_map_user(struct request_queue q, struct request rq,
152e283f FT	112	struct rq_map_data map_data, void __user ubuf,
152e283f FT	113	unsigned long len, gfp_t gfp_mask)
86db1e29 JA	114	{
	115	unsigned long bytes_read = 0;
	116	struct bio *bio = NULL;
81882766	117	int ret, null_mapped = 0;
86db1e29 JA	118
	119	if (len > (q->max_hw_sectors << 9))
	120	return -EINVAL;
81882766	121	if (!len)
86db1e29	122	return -EINVAL;
81882766 FT	123	if (!ubuf) {
	124	if (!map_data \|\| rq_data_dir(rq) != READ)
	125	return -EINVAL;
	126	null_mapped = 1;
	127	}
86db1e29 JA	128
	129	while (bytes_read != len) {
	130	unsigned long map_len, end, start;
	131
	132	map_len = min_t(unsigned long, len - bytes_read, BIO_MAX_SIZE);
	133	end = ((unsigned long)ubuf + map_len + PAGE_SIZE - 1)
	134	>> PAGE_SHIFT;
	135	start = (unsigned long)ubuf >> PAGE_SHIFT;
	136
	137	/*
	138	* A bad offset could cause us to require BIO_MAX_PAGES + 1
	139	* pages. If this happens we just lower the requested
	140	* mapping len by a page so that we can fit
	141	*/
	142	if (end - start > BIO_MAX_PAGES)
	143	map_len -= PAGE_SIZE;
	144
152e283f	145	ret = __blk_rq_map_user(q, rq, map_data, ubuf, map_len,
81882766	146	null_mapped, gfp_mask);
86db1e29 JA	147	if (ret < 0)
	148	goto unmap_rq;
	149	if (!bio)
	150	bio = rq->bio;
	151	bytes_read += ret;
	152	ubuf += ret;
	153	}
	154
f18573ab FT	155	if (!bio_flagged(bio, BIO_USER_MAPPED))
f18573ab FT	156	rq->cmd_flags \|= REQ_COPY_USER;
40b01b9b	157
86db1e29 JA	158	rq->buffer = rq->data = NULL;
	159	return 0;
	160	unmap_rq:
	161	blk_rq_unmap_user(bio);
84e9e03c	162	rq->bio = NULL;
86db1e29 JA	163	return ret;
86db1e29 JA	164	}
86db1e29 JA	165	EXPORT_SYMBOL(blk_rq_map_user);
	166
	167	/**
710027a4	168	* blk_rq_map_user_iov - map user data to a request, for REQ_TYPE_BLOCK_PC usage
86db1e29 JA	169	* @q: request queue where request should be inserted
86db1e29 JA	170	* @rq: request to map data to
152e283f	171	* @map_data: pointer to the rq_map_data holding pages (if necessary)
86db1e29 JA	172	* @iov: pointer to the iovec
	173	* @iov_count: number of elements in the iovec
	174	* @len: I/O byte count
a3bce90e	175	* @gfp_mask: memory allocation flags
86db1e29 JA	176	*
86db1e29 JA	177	* Description:
710027a4	178	* Data will be mapped directly for zero copy I/O, if possible. Otherwise
86db1e29 JA	179	* a kernel bounce buffer is used.
86db1e29 JA	180	*
710027a4	181	* A matching blk_rq_unmap_user() must be issued at the end of I/O, while
86db1e29 JA	182	* still in process context.
	183	*
	184	* Note: The mapped bio may need to be bounced through blk_queue_bounce()
	185	* before being submitted to the device, as pages mapped may be out of
	186	* reach. It's the callers responsibility to make sure this happens. The
	187	* original bio must be passed back in to blk_rq_unmap_user() for proper
	188	* unmapping.
	189	*/
	190	int blk_rq_map_user_iov(struct request_queue q, struct request rq,
152e283f FT	191	struct rq_map_data map_data, struct sg_iovec iov,
152e283f FT	192	int iov_count, unsigned int len, gfp_t gfp_mask)
86db1e29 JA	193	{
86db1e29 JA	194	struct bio *bio;
afdc1a78 FT	195	int i, read = rq_data_dir(rq) == READ;
afdc1a78 FT	196	int unaligned = 0;
86db1e29 JA	197
	198	if (!iov \|\| iov_count <= 0)
	199	return -EINVAL;
	200
afdc1a78 FT	201	for (i = 0; i < iov_count; i++) {
	202	unsigned long uaddr = (unsigned long)iov[i].iov_base;
	203
	204	if (uaddr & queue_dma_alignment(q)) {
	205	unaligned = 1;
	206	break;
	207	}
	208	}
	209
152e283f FT	210	if (unaligned \|\| (q->dma_pad_mask & len) \|\| map_data)
	211	bio = bio_copy_user_iov(q, map_data, iov, iov_count, read,
	212	gfp_mask);
afdc1a78	213	else
a3bce90e	214	bio = bio_map_user_iov(q, NULL, iov, iov_count, read, gfp_mask);
afdc1a78	215
86db1e29 JA	216	if (IS_ERR(bio))
	217	return PTR_ERR(bio);
	218
	219	if (bio->bi_size != len) {
c26156b2 JA	220	/*
	221	* Grab an extra reference to this bio, as bio_unmap_user()
	222	* expects to be able to drop it twice as it happens on the
	223	* normal IO completion path
	224	*/
	225	bio_get(bio);
86db1e29	226	bio_endio(bio, 0);
53cc0b29	227	__blk_rq_unmap_user(bio);
86db1e29 JA	228	return -EINVAL;
	229	}
	230
f18573ab FT	231	if (!bio_flagged(bio, BIO_USER_MAPPED))
	232	rq->cmd_flags \|= REQ_COPY_USER;
	233
07359fc6	234	blk_queue_bounce(q, &bio);
86db1e29 JA	235	bio_get(bio);
	236	blk_rq_bio_prep(q, rq, bio);
	237	rq->buffer = rq->data = NULL;
	238	return 0;
	239	}
152e283f	240	EXPORT_SYMBOL(blk_rq_map_user_iov);
86db1e29 JA	241
	242	/**
	243	* blk_rq_unmap_user - unmap a request with user data
	244	* @bio: start of bio list
	245	*
	246	* Description:
	247	* Unmap a rq previously mapped by blk_rq_map_user(). The caller must
	248	* supply the original rq->bio from the blk_rq_map_user() return, since
710027a4	249	* the I/O completion may have changed rq->bio.
86db1e29 JA	250	*/
	251	int blk_rq_unmap_user(struct bio *bio)
	252	{
	253	struct bio *mapped_bio;
	254	int ret = 0, ret2;
	255
	256	while (bio) {
	257	mapped_bio = bio;
	258	if (unlikely(bio_flagged(bio, BIO_BOUNCED)))
	259	mapped_bio = bio->bi_private;
	260
	261	ret2 = __blk_rq_unmap_user(mapped_bio);
	262	if (ret2 && !ret)
	263	ret = ret2;
	264
	265	mapped_bio = bio;
	266	bio = bio->bi_next;
	267	bio_put(mapped_bio);
	268	}
	269
	270	return ret;
	271	}
86db1e29 JA	272	EXPORT_SYMBOL(blk_rq_unmap_user);
	273
	274	/**
710027a4	275	* blk_rq_map_kern - map kernel data to a request, for REQ_TYPE_BLOCK_PC usage
86db1e29 JA	276	* @q: request queue where request should be inserted
	277	* @rq: request to fill
	278	* @kbuf: the kernel buffer
	279	* @len: length of user data
	280	* @gfp_mask: memory allocation flags
68154e90 FT	281	*
	282	* Description:
	283	* Data will be mapped directly if possible. Otherwise a bounce
	284	* buffer is used.
86db1e29 JA	285	*/
	286	int blk_rq_map_kern(struct request_queue q, struct request rq, void *kbuf,
	287	unsigned int len, gfp_t gfp_mask)
	288	{
68154e90 FT	289	int reading = rq_data_dir(rq) == READ;
68154e90 FT	290	int do_copy = 0;
86db1e29 JA	291	struct bio *bio;
	292
	293	if (len > (q->max_hw_sectors << 9))
	294	return -EINVAL;
	295	if (!len \|\| !kbuf)
	296	return -EINVAL;
	297
87904074	298	do_copy = !blk_rq_aligned(q, kbuf, len) \|\| object_is_on_stack(kbuf);
68154e90 FT	299	if (do_copy)
	300	bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
	301	else
	302	bio = bio_map_kern(q, kbuf, len, gfp_mask);
	303
86db1e29 JA	304	if (IS_ERR(bio))
	305	return PTR_ERR(bio);
	306
	307	if (rq_data_dir(rq) == WRITE)
	308	bio->bi_rw \|= (1 << BIO_RW);
	309
68154e90 FT	310	if (do_copy)
	311	rq->cmd_flags \|= REQ_COPY_USER;
	312
86db1e29 JA	313	blk_rq_bio_prep(q, rq, bio);
	314	blk_queue_bounce(q, &rq->bio);
	315	rq->buffer = rq->data = NULL;
	316	return 0;
	317	}
86db1e29	318	EXPORT_SYMBOL(blk_rq_map_kern);