[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,
			     void __user *ubuf, unsigned int len,
			     gfp_t gfp_mask)
{
	unsigned long uaddr;
	unsigned int alignment;
	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;
	alignment = queue_dma_alignment(q) | q->dma_pad_mask;
	if (!(uaddr & alignment) && !(len & alignment))
		bio = bio_map_user(q, NULL, uaddr, len, reading, gfp_mask);
	else
		bio = bio_copy_user(q, 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
 * @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,
		    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, 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
 * @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 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))
		bio = bio_copy_user_iov(q, 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;
}

/**
 * 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)
{
	unsigned long kaddr;
	unsigned int alignment;
	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;

	kaddr = (unsigned long)kbuf;
	alignment = queue_dma_alignment(q) | q->dma_pad_mask;
	do_copy = ((kaddr & alignment) || (len & alignment) ||
		   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,
a3bce90e FT	44	void __user *ubuf, unsigned int len,
a3bce90e FT	45	gfp_t gfp_mask)
86db1e29 JA	46	{
86db1e29 JA	47	unsigned long uaddr;
e3790c7d	48	unsigned int alignment;
86db1e29 JA	49	struct bio bio, orig_bio;
	50	int reading, ret;
	51
	52	reading = rq_data_dir(rq) == READ;
	53
	54	/*
	55	* if alignment requirement is satisfied, map in user pages for
	56	* direct dma. else, set up kernel bounce buffers
	57	*/
	58	uaddr = (unsigned long) ubuf;
e3790c7d TH	59	alignment = queue_dma_alignment(q) \| q->dma_pad_mask;
e3790c7d TH	60	if (!(uaddr & alignment) && !(len & alignment))
a3bce90e	61	bio = bio_map_user(q, NULL, uaddr, len, reading, gfp_mask);
86db1e29	62	else
a3bce90e	63	bio = bio_copy_user(q, uaddr, len, reading, gfp_mask);
86db1e29 JA	64
	65	if (IS_ERR(bio))
	66	return PTR_ERR(bio);
	67
	68	orig_bio = bio;
	69	blk_queue_bounce(q, &bio);
	70
	71	/*
	72	* We link the bounce buffer in and could have to traverse it
	73	* later so we have to get a ref to prevent it from being freed
	74	*/
	75	bio_get(bio);
	76
	77	ret = blk_rq_append_bio(q, rq, bio);
	78	if (!ret)
	79	return bio->bi_size;
	80
	81	/* if it was boucned we must call the end io function */
	82	bio_endio(bio, 0);
	83	__blk_rq_unmap_user(orig_bio);
	84	bio_put(bio);
	85	return ret;
	86	}
	87
	88	/**
710027a4	89	* blk_rq_map_user - map user data to a request, for REQ_TYPE_BLOCK_PC usage
86db1e29 JA	90	* @q: request queue where request should be inserted
	91	* @rq: request structure to fill
	92	* @ubuf: the user buffer
	93	* @len: length of user data
a3bce90e	94	* @gfp_mask: memory allocation flags
86db1e29 JA	95	*
86db1e29 JA	96	* Description:
710027a4	97	* Data will be mapped directly for zero copy I/O, if possible. Otherwise
86db1e29 JA	98	* a kernel bounce buffer is used.
86db1e29 JA	99	*
710027a4	100	* A matching blk_rq_unmap_user() must be issued at the end of I/O, while
86db1e29 JA	101	* still in process context.
	102	*
	103	* Note: The mapped bio may need to be bounced through blk_queue_bounce()
	104	* before being submitted to the device, as pages mapped may be out of
	105	* reach. It's the callers responsibility to make sure this happens. The
	106	* original bio must be passed back in to blk_rq_unmap_user() for proper
	107	* unmapping.
	108	*/
	109	int blk_rq_map_user(struct request_queue q, struct request rq,
a3bce90e	110	void __user *ubuf, 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
a3bce90e	137	ret = __blk_rq_map_user(q, rq, ubuf, map_len, gfp_mask);
86db1e29 JA	138	if (ret < 0)
	139	goto unmap_rq;
	140	if (!bio)
	141	bio = rq->bio;
	142	bytes_read += ret;
	143	ubuf += ret;
	144	}
	145
f18573ab FT	146	if (!bio_flagged(bio, BIO_USER_MAPPED))
f18573ab FT	147	rq->cmd_flags \|= REQ_COPY_USER;
40b01b9b	148
86db1e29 JA	149	rq->buffer = rq->data = NULL;
	150	return 0;
	151	unmap_rq:
	152	blk_rq_unmap_user(bio);
84e9e03c	153	rq->bio = NULL;
86db1e29 JA	154	return ret;
86db1e29 JA	155	}
86db1e29 JA	156	EXPORT_SYMBOL(blk_rq_map_user);
	157
	158	/**
710027a4	159	* blk_rq_map_user_iov - map user data to a request, for REQ_TYPE_BLOCK_PC usage
86db1e29 JA	160	* @q: request queue where request should be inserted
	161	* @rq: request to map data to
	162	* @iov: pointer to the iovec
	163	* @iov_count: number of elements in the iovec
	164	* @len: I/O byte count
a3bce90e	165	* @gfp_mask: memory allocation flags
86db1e29 JA	166	*
86db1e29 JA	167	* Description:
710027a4	168	* Data will be mapped directly for zero copy I/O, if possible. Otherwise
86db1e29 JA	169	* a kernel bounce buffer is used.
86db1e29 JA	170	*
710027a4	171	* A matching blk_rq_unmap_user() must be issued at the end of I/O, while
86db1e29 JA	172	* still in process context.
	173	*
	174	* Note: The mapped bio may need to be bounced through blk_queue_bounce()
	175	* before being submitted to the device, as pages mapped may be out of
	176	* reach. It's the callers responsibility to make sure this happens. The
	177	* original bio must be passed back in to blk_rq_unmap_user() for proper
	178	* unmapping.
	179	*/
	180	int blk_rq_map_user_iov(struct request_queue q, struct request rq,
a3bce90e FT	181	struct sg_iovec *iov, int iov_count, unsigned int len,
a3bce90e FT	182	gfp_t gfp_mask)
86db1e29 JA	183	{
86db1e29 JA	184	struct bio *bio;
afdc1a78 FT	185	int i, read = rq_data_dir(rq) == READ;
afdc1a78 FT	186	int unaligned = 0;
86db1e29 JA	187
	188	if (!iov \|\| iov_count <= 0)
	189	return -EINVAL;
	190
afdc1a78 FT	191	for (i = 0; i < iov_count; i++) {
	192	unsigned long uaddr = (unsigned long)iov[i].iov_base;
	193
	194	if (uaddr & queue_dma_alignment(q)) {
	195	unaligned = 1;
	196	break;
	197	}
	198	}
	199
	200	if (unaligned \|\| (q->dma_pad_mask & len))
a3bce90e	201	bio = bio_copy_user_iov(q, iov, iov_count, read, gfp_mask);
afdc1a78	202	else
a3bce90e	203	bio = bio_map_user_iov(q, NULL, iov, iov_count, read, gfp_mask);
afdc1a78	204
86db1e29 JA	205	if (IS_ERR(bio))
	206	return PTR_ERR(bio);
	207
	208	if (bio->bi_size != len) {
	209	bio_endio(bio, 0);
	210	bio_unmap_user(bio);
	211	return -EINVAL;
	212	}
	213
f18573ab FT	214	if (!bio_flagged(bio, BIO_USER_MAPPED))
	215	rq->cmd_flags \|= REQ_COPY_USER;
	216
07359fc6	217	blk_queue_bounce(q, &bio);
86db1e29 JA	218	bio_get(bio);
	219	blk_rq_bio_prep(q, rq, bio);
	220	rq->buffer = rq->data = NULL;
	221	return 0;
	222	}
86db1e29 JA	223
	224	/**
	225	* blk_rq_unmap_user - unmap a request with user data
	226	* @bio: start of bio list
	227	*
	228	* Description:
	229	* Unmap a rq previously mapped by blk_rq_map_user(). The caller must
	230	* supply the original rq->bio from the blk_rq_map_user() return, since
710027a4	231	* the I/O completion may have changed rq->bio.
86db1e29 JA	232	*/
	233	int blk_rq_unmap_user(struct bio *bio)
	234	{
	235	struct bio *mapped_bio;
	236	int ret = 0, ret2;
	237
	238	while (bio) {
	239	mapped_bio = bio;
	240	if (unlikely(bio_flagged(bio, BIO_BOUNCED)))
	241	mapped_bio = bio->bi_private;
	242
	243	ret2 = __blk_rq_unmap_user(mapped_bio);
	244	if (ret2 && !ret)
	245	ret = ret2;
	246
	247	mapped_bio = bio;
	248	bio = bio->bi_next;
	249	bio_put(mapped_bio);
	250	}
	251
	252	return ret;
	253	}
86db1e29 JA	254	EXPORT_SYMBOL(blk_rq_unmap_user);
	255
	256	/**
710027a4	257	* blk_rq_map_kern - map kernel data to a request, for REQ_TYPE_BLOCK_PC usage
86db1e29 JA	258	* @q: request queue where request should be inserted
	259	* @rq: request to fill
	260	* @kbuf: the kernel buffer
	261	* @len: length of user data
	262	* @gfp_mask: memory allocation flags
68154e90 FT	263	*
	264	* Description:
	265	* Data will be mapped directly if possible. Otherwise a bounce
	266	* buffer is used.
86db1e29 JA	267	*/
	268	int blk_rq_map_kern(struct request_queue q, struct request rq, void *kbuf,
	269	unsigned int len, gfp_t gfp_mask)
	270	{
68154e90 FT	271	unsigned long kaddr;
	272	unsigned int alignment;
	273	int reading = rq_data_dir(rq) == READ;
	274	int do_copy = 0;
86db1e29 JA	275	struct bio *bio;
	276
	277	if (len > (q->max_hw_sectors << 9))
	278	return -EINVAL;
	279	if (!len \|\| !kbuf)
	280	return -EINVAL;
	281
68154e90 FT	282	kaddr = (unsigned long)kbuf;
68154e90 FT	283	alignment = queue_dma_alignment(q) \| q->dma_pad_mask;
a76eef95 FT	284	do_copy = ((kaddr & alignment) \|\| (len & alignment) \|\|
a76eef95 FT	285	object_is_on_stack(kbuf));
30c00eda	286
68154e90 FT	287	if (do_copy)
	288	bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
	289	else
	290	bio = bio_map_kern(q, kbuf, len, gfp_mask);
	291
86db1e29 JA	292	if (IS_ERR(bio))
	293	return PTR_ERR(bio);
	294
	295	if (rq_data_dir(rq) == WRITE)
	296	bio->bi_rw \|= (1 << BIO_RW);
	297
68154e90 FT	298	if (do_copy)
	299	rq->cmd_flags \|= REQ_COPY_USER;
	300
86db1e29 JA	301	blk_rq_bio_prep(q, rq, bio);
	302	blk_queue_bounce(q, &rq->bio);
	303	rq->buffer = rq->data = NULL;
	304	return 0;
	305	}
86db1e29	306	EXPORT_SYMBOL(blk_rq_map_kern);