[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);

	if (map_data && map_data->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;

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

	if (!ubuf && (!map_data || !map_data->null_mapped))
		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 (map_data)
			map_data->offset += ret;
	}

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

	rq->buffer = 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 = 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 = 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
a2dec7b3	23	rq->__data_len += bio->bi_size;
86db1e29 JA	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,
97ae77a1	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
97ae77a1	66	if (map_data && map_data->null_mapped)
81882766 FT	67	bio->bi_flags \|= (1 << BIO_NULL_MAPPED);
81882766 FT	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;
97ae77a1	117	int ret;
86db1e29 JA	118
	119	if (len > (q->max_hw_sectors << 9))
	120	return -EINVAL;
81882766	121	if (!len)
86db1e29	122	return -EINVAL;
97ae77a1 FT	123
	124	if (!ubuf && (!map_data \|\| !map_data->null_mapped))
	125	return -EINVAL;
86db1e29 JA	126
	127	while (bytes_read != len) {
	128	unsigned long map_len, end, start;
	129
	130	map_len = min_t(unsigned long, len - bytes_read, BIO_MAX_SIZE);
	131	end = ((unsigned long)ubuf + map_len + PAGE_SIZE - 1)
	132	>> PAGE_SHIFT;
	133	start = (unsigned long)ubuf >> PAGE_SHIFT;
	134
	135	/*
	136	* A bad offset could cause us to require BIO_MAX_PAGES + 1
	137	* pages. If this happens we just lower the requested
	138	* mapping len by a page so that we can fit
	139	*/
	140	if (end - start > BIO_MAX_PAGES)
	141	map_len -= PAGE_SIZE;
	142
152e283f	143	ret = __blk_rq_map_user(q, rq, map_data, ubuf, map_len,
97ae77a1	144	gfp_mask);
86db1e29 JA	145	if (ret < 0)
	146	goto unmap_rq;
	147	if (!bio)
	148	bio = rq->bio;
	149	bytes_read += ret;
	150	ubuf += ret;
56c451f4 FT	151
	152	if (map_data)
	153	map_data->offset += ret;
86db1e29 JA	154	}
86db1e29 JA	155
f18573ab FT	156	if (!bio_flagged(bio, BIO_USER_MAPPED))
f18573ab FT	157	rq->cmd_flags \|= REQ_COPY_USER;
40b01b9b	158
731ec497	159	rq->buffer = NULL;
86db1e29 JA	160	return 0;
	161	unmap_rq:
	162	blk_rq_unmap_user(bio);
84e9e03c	163	rq->bio = NULL;
86db1e29 JA	164	return ret;
86db1e29 JA	165	}
86db1e29 JA	166	EXPORT_SYMBOL(blk_rq_map_user);
	167
	168	/**
710027a4	169	* blk_rq_map_user_iov - map user data to a request, for REQ_TYPE_BLOCK_PC usage
86db1e29 JA	170	* @q: request queue where request should be inserted
86db1e29 JA	171	* @rq: request to map data to
152e283f	172	* @map_data: pointer to the rq_map_data holding pages (if necessary)
86db1e29 JA	173	* @iov: pointer to the iovec
	174	* @iov_count: number of elements in the iovec
	175	* @len: I/O byte count
a3bce90e	176	* @gfp_mask: memory allocation flags
86db1e29 JA	177	*
86db1e29 JA	178	* Description:
710027a4	179	* Data will be mapped directly for zero copy I/O, if possible. Otherwise
86db1e29 JA	180	* a kernel bounce buffer is used.
86db1e29 JA	181	*
710027a4	182	* A matching blk_rq_unmap_user() must be issued at the end of I/O, while
86db1e29 JA	183	* still in process context.
	184	*
	185	* Note: The mapped bio may need to be bounced through blk_queue_bounce()
	186	* before being submitted to the device, as pages mapped may be out of
	187	* reach. It's the callers responsibility to make sure this happens. The
	188	* original bio must be passed back in to blk_rq_unmap_user() for proper
	189	* unmapping.
	190	*/
	191	int blk_rq_map_user_iov(struct request_queue q, struct request rq,
152e283f FT	192	struct rq_map_data map_data, struct sg_iovec iov,
152e283f FT	193	int iov_count, unsigned int len, gfp_t gfp_mask)
86db1e29 JA	194	{
86db1e29 JA	195	struct bio *bio;
afdc1a78 FT	196	int i, read = rq_data_dir(rq) == READ;
afdc1a78 FT	197	int unaligned = 0;
86db1e29 JA	198
	199	if (!iov \|\| iov_count <= 0)
	200	return -EINVAL;
	201
afdc1a78 FT	202	for (i = 0; i < iov_count; i++) {
	203	unsigned long uaddr = (unsigned long)iov[i].iov_base;
	204
	205	if (uaddr & queue_dma_alignment(q)) {
	206	unaligned = 1;
	207	break;
	208	}
	209	}
	210
152e283f FT	211	if (unaligned \|\| (q->dma_pad_mask & len) \|\| map_data)
	212	bio = bio_copy_user_iov(q, map_data, iov, iov_count, read,
	213	gfp_mask);
afdc1a78	214	else
a3bce90e	215	bio = bio_map_user_iov(q, NULL, iov, iov_count, read, gfp_mask);
afdc1a78	216
86db1e29 JA	217	if (IS_ERR(bio))
	218	return PTR_ERR(bio);
	219
	220	if (bio->bi_size != len) {
c26156b2 JA	221	/*
	222	* Grab an extra reference to this bio, as bio_unmap_user()
	223	* expects to be able to drop it twice as it happens on the
	224	* normal IO completion path
	225	*/
	226	bio_get(bio);
86db1e29	227	bio_endio(bio, 0);
53cc0b29	228	__blk_rq_unmap_user(bio);
86db1e29 JA	229	return -EINVAL;
	230	}
	231
f18573ab FT	232	if (!bio_flagged(bio, BIO_USER_MAPPED))
	233	rq->cmd_flags \|= REQ_COPY_USER;
	234
07359fc6	235	blk_queue_bounce(q, &bio);
86db1e29 JA	236	bio_get(bio);
86db1e29 JA	237	blk_rq_bio_prep(q, rq, bio);
731ec497	238	rq->buffer = NULL;
86db1e29 JA	239	return 0;
86db1e29 JA	240	}
152e283f	241	EXPORT_SYMBOL(blk_rq_map_user_iov);
86db1e29 JA	242
	243	/**
	244	* blk_rq_unmap_user - unmap a request with user data
	245	* @bio: start of bio list
	246	*
	247	* Description:
	248	* Unmap a rq previously mapped by blk_rq_map_user(). The caller must
	249	* supply the original rq->bio from the blk_rq_map_user() return, since
710027a4	250	* the I/O completion may have changed rq->bio.
86db1e29 JA	251	*/
	252	int blk_rq_unmap_user(struct bio *bio)
	253	{
	254	struct bio *mapped_bio;
	255	int ret = 0, ret2;
	256
	257	while (bio) {
	258	mapped_bio = bio;
	259	if (unlikely(bio_flagged(bio, BIO_BOUNCED)))
	260	mapped_bio = bio->bi_private;
	261
	262	ret2 = __blk_rq_unmap_user(mapped_bio);
	263	if (ret2 && !ret)
	264	ret = ret2;
	265
	266	mapped_bio = bio;
	267	bio = bio->bi_next;
	268	bio_put(mapped_bio);
	269	}
	270
	271	return ret;
	272	}
86db1e29 JA	273	EXPORT_SYMBOL(blk_rq_unmap_user);
	274
	275	/**
710027a4	276	* blk_rq_map_kern - map kernel data to a request, for REQ_TYPE_BLOCK_PC usage
86db1e29 JA	277	* @q: request queue where request should be inserted
	278	* @rq: request to fill
	279	* @kbuf: the kernel buffer
	280	* @len: length of user data
	281	* @gfp_mask: memory allocation flags
68154e90 FT	282	*
	283	* Description:
	284	* Data will be mapped directly if possible. Otherwise a bounce
	285	* buffer is used.
86db1e29 JA	286	*/
	287	int blk_rq_map_kern(struct request_queue q, struct request rq, void *kbuf,
	288	unsigned int len, gfp_t gfp_mask)
	289	{
68154e90 FT	290	int reading = rq_data_dir(rq) == READ;
68154e90 FT	291	int do_copy = 0;
86db1e29 JA	292	struct bio *bio;
	293
	294	if (len > (q->max_hw_sectors << 9))
	295	return -EINVAL;
	296	if (!len \|\| !kbuf)
	297	return -EINVAL;
	298
87904074	299	do_copy = !blk_rq_aligned(q, kbuf, len) \|\| object_is_on_stack(kbuf);
68154e90 FT	300	if (do_copy)
	301	bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
	302	else
	303	bio = bio_map_kern(q, kbuf, len, gfp_mask);
	304
86db1e29 JA	305	if (IS_ERR(bio))
	306	return PTR_ERR(bio);
	307
	308	if (rq_data_dir(rq) == WRITE)
	309	bio->bi_rw \|= (1 << BIO_RW);
	310
68154e90 FT	311	if (do_copy)
	312	rq->cmd_flags \|= REQ_COPY_USER;
	313
86db1e29 JA	314	blk_rq_bio_prep(q, rq, bio);
86db1e29 JA	315	blk_queue_bounce(q, &rq->bio);
731ec497	316	rq->buffer = NULL;
86db1e29 JA	317	return 0;
86db1e29 JA	318	}
86db1e29	319	EXPORT_SYMBOL(blk_rq_map_kern);