[net-next-2.6.git] / net / rds / message.c

/*
 * Copyright (c) 2006 Oracle.  All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */
#include <linux/kernel.h>
#include <linux/slab.h>

#include "rds.h"

static unsigned int	rds_exthdr_size[__RDS_EXTHDR_MAX] = {
[RDS_EXTHDR_NONE]	= 0,
[RDS_EXTHDR_VERSION]	= sizeof(struct rds_ext_header_version),
[RDS_EXTHDR_RDMA]	= sizeof(struct rds_ext_header_rdma),
[RDS_EXTHDR_RDMA_DEST]	= sizeof(struct rds_ext_header_rdma_dest),
};


void rds_message_addref(struct rds_message *rm)
{
	rdsdebug("addref rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
	atomic_inc(&rm->m_refcount);
}
EXPORT_SYMBOL_GPL(rds_message_addref);

/*
 * This relies on dma_map_sg() not touching sg[].page during merging.
 */
static void rds_message_purge(struct rds_message *rm)
{
	unsigned long i;

	if (unlikely(test_bit(RDS_MSG_PAGEVEC, &rm->m_flags)))
		return;

	for (i = 0; i < rm->data.op_nents; i++) {
		rdsdebug("putting data page %p\n", (void *)sg_page(&rm->data.op_sg[i]));
		/* XXX will have to put_page for page refs */
		__free_page(sg_page(&rm->data.op_sg[i]));
	}
	rm->data.op_nents = 0;

	if (rm->rdma.op_active)
		rds_rdma_free_op(&rm->rdma);
	if (rm->rdma.op_rdma_mr)
		rds_mr_put(rm->rdma.op_rdma_mr);

	if (rm->atomic.op_active)
		rds_atomic_free_op(&rm->atomic);
	if (rm->atomic.op_rdma_mr)
		rds_mr_put(rm->atomic.op_rdma_mr);
}

void rds_message_put(struct rds_message *rm)
{
	rdsdebug("put rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));

	if (atomic_dec_and_test(&rm->m_refcount)) {
		BUG_ON(!list_empty(&rm->m_sock_item));
		BUG_ON(!list_empty(&rm->m_conn_item));
		rds_message_purge(rm);

		kfree(rm);
	}
}
EXPORT_SYMBOL_GPL(rds_message_put);

void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
				 __be16 dport, u64 seq)
{
	hdr->h_flags = 0;
	hdr->h_sport = sport;
	hdr->h_dport = dport;
	hdr->h_sequence = cpu_to_be64(seq);
	hdr->h_exthdr[0] = RDS_EXTHDR_NONE;
}
EXPORT_SYMBOL_GPL(rds_message_populate_header);

int rds_message_add_extension(struct rds_header *hdr,
		unsigned int type, const void *data, unsigned int len)
{
	unsigned int ext_len = sizeof(u8) + len;
	unsigned char *dst;

	/* For now, refuse to add more than one extension header */
	if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE)
		return 0;

	if (type >= __RDS_EXTHDR_MAX || len != rds_exthdr_size[type])
		return 0;

	if (ext_len >= RDS_HEADER_EXT_SPACE)
		return 0;
	dst = hdr->h_exthdr;

	*dst++ = type;
	memcpy(dst, data, len);

	dst[len] = RDS_EXTHDR_NONE;
	return 1;
}
EXPORT_SYMBOL_GPL(rds_message_add_extension);

/*
 * If a message has extension headers, retrieve them here.
 * Call like this:
 *
 * unsigned int pos = 0;
 *
 * while (1) {
 *	buflen = sizeof(buffer);
 *	type = rds_message_next_extension(hdr, &pos, buffer, &buflen);
 *	if (type == RDS_EXTHDR_NONE)
 *		break;
 *	...
 * }
 */
int rds_message_next_extension(struct rds_header *hdr,
		unsigned int *pos, void *buf, unsigned int *buflen)
{
	unsigned int offset, ext_type, ext_len;
	u8 *src = hdr->h_exthdr;

	offset = *pos;
	if (offset >= RDS_HEADER_EXT_SPACE)
		goto none;

	/* Get the extension type and length. For now, the
	 * length is implied by the extension type. */
	ext_type = src[offset++];

	if (ext_type == RDS_EXTHDR_NONE || ext_type >= __RDS_EXTHDR_MAX)
		goto none;
	ext_len = rds_exthdr_size[ext_type];
	if (offset + ext_len > RDS_HEADER_EXT_SPACE)
		goto none;

	*pos = offset + ext_len;
	if (ext_len < *buflen)
		*buflen = ext_len;
	memcpy(buf, src + offset, *buflen);
	return ext_type;

none:
	*pos = RDS_HEADER_EXT_SPACE;
	*buflen = 0;
	return RDS_EXTHDR_NONE;
}

int rds_message_add_version_extension(struct rds_header *hdr, unsigned int version)
{
	struct rds_ext_header_version ext_hdr;

	ext_hdr.h_version = cpu_to_be32(version);
	return rds_message_add_extension(hdr, RDS_EXTHDR_VERSION, &ext_hdr, sizeof(ext_hdr));
}

int rds_message_get_version_extension(struct rds_header *hdr, unsigned int *version)
{
	struct rds_ext_header_version ext_hdr;
	unsigned int pos = 0, len = sizeof(ext_hdr);

	/* We assume the version extension is the only one present */
	if (rds_message_next_extension(hdr, &pos, &ext_hdr, &len) != RDS_EXTHDR_VERSION)
		return 0;
	*version = be32_to_cpu(ext_hdr.h_version);
	return 1;
}

int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset)
{
	struct rds_ext_header_rdma_dest ext_hdr;

	ext_hdr.h_rdma_rkey = cpu_to_be32(r_key);
	ext_hdr.h_rdma_offset = cpu_to_be32(offset);
	return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr));
}
EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension);

/*
 * Each rds_message is allocated with extra space for the scatterlist entries
 * rds ops will need. This is to minimize memory allocation count. Then, each rds op
 * can grab SGs when initializing its part of the rds_message.
 */
struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp)
{
	struct rds_message *rm;

	rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp);
	if (!rm)
		goto out;

	rm->m_used_sgs = 0;
	rm->m_total_sgs = extra_len / sizeof(struct scatterlist);

	atomic_set(&rm->m_refcount, 1);
	INIT_LIST_HEAD(&rm->m_sock_item);
	INIT_LIST_HEAD(&rm->m_conn_item);
	spin_lock_init(&rm->m_rs_lock);
	init_waitqueue_head(&rm->m_flush_wait);

out:
	return rm;
}

/*
 * RDS ops use this to grab SG entries from the rm's sg pool.
 */
struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents)
{
	struct scatterlist *sg_first = (struct scatterlist *) &rm[1];
	struct scatterlist *sg_ret;

	WARN_ON(rm->m_used_sgs + nents > rm->m_total_sgs);
	WARN_ON(!nents);

	sg_ret = &sg_first[rm->m_used_sgs];
	sg_init_table(sg_ret, nents);
	rm->m_used_sgs += nents;

	return sg_ret;
}

struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len)
{
	struct rds_message *rm;
	unsigned int i;
	int num_sgs = ceil(total_len, PAGE_SIZE);
	int extra_bytes = num_sgs * sizeof(struct scatterlist);

	rm = rds_message_alloc(extra_bytes, GFP_NOWAIT);
	if (!rm)
		return ERR_PTR(-ENOMEM);

	set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
	rm->data.op_nents = ceil(total_len, PAGE_SIZE);
	rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);

	for (i = 0; i < rm->data.op_nents; ++i) {
		sg_set_page(&rm->data.op_sg[i],
				virt_to_page(page_addrs[i]),
				PAGE_SIZE, 0);
	}

	return rm;
}

int rds_message_copy_from_user(struct rds_message *rm, struct iovec *first_iov,
					       size_t total_len)
{
	unsigned long to_copy;
	unsigned long iov_off;
	unsigned long sg_off;
	struct iovec *iov;
	struct scatterlist *sg;
	int ret = 0;

	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);

	/*
	 * now allocate and copy in the data payload.
	 */
	sg = rm->data.op_sg;
	iov = first_iov;
	iov_off = 0;
	sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */

	while (total_len) {
		if (!sg_page(sg)) {
			ret = rds_page_remainder_alloc(sg, total_len,
						       GFP_HIGHUSER);
			if (ret)
				goto out;
			rm->data.op_nents++;
			sg_off = 0;
		}

		while (iov_off == iov->iov_len) {
			iov_off = 0;
			iov++;
		}

		to_copy = min(iov->iov_len - iov_off, sg->length - sg_off);
		to_copy = min_t(size_t, to_copy, total_len);

		rdsdebug("copying %lu bytes from user iov [%p, %zu] + %lu to "
			 "sg [%p, %u, %u] + %lu\n",
			 to_copy, iov->iov_base, iov->iov_len, iov_off,
			 (void *)sg_page(sg), sg->offset, sg->length, sg_off);

		ret = rds_page_copy_from_user(sg_page(sg), sg->offset + sg_off,
					      iov->iov_base + iov_off,
					      to_copy);
		if (ret)
			goto out;

		iov_off += to_copy;
		total_len -= to_copy;
		sg_off += to_copy;

		if (sg_off == sg->length)
			sg++;
	}

out:
	return ret;
}

int rds_message_inc_copy_to_user(struct rds_incoming *inc,
				 struct iovec *first_iov, size_t size)
{
	struct rds_message *rm;
	struct iovec *iov;
	struct scatterlist *sg;
	unsigned long to_copy;
	unsigned long iov_off;
	unsigned long vec_off;
	int copied;
	int ret;
	u32 len;

	rm = container_of(inc, struct rds_message, m_inc);
	len = be32_to_cpu(rm->m_inc.i_hdr.h_len);

	iov = first_iov;
	iov_off = 0;
	sg = rm->data.op_sg;
	vec_off = 0;
	copied = 0;

	while (copied < size && copied < len) {
		while (iov_off == iov->iov_len) {
			iov_off = 0;
			iov++;
		}

		to_copy = min(iov->iov_len - iov_off, sg->length - vec_off);
		to_copy = min_t(size_t, to_copy, size - copied);
		to_copy = min_t(unsigned long, to_copy, len - copied);

		rdsdebug("copying %lu bytes to user iov [%p, %zu] + %lu to "
			 "sg [%p, %u, %u] + %lu\n",
			 to_copy, iov->iov_base, iov->iov_len, iov_off,
			 sg_page(sg), sg->offset, sg->length, vec_off);

		ret = rds_page_copy_to_user(sg_page(sg), sg->offset + vec_off,
					    iov->iov_base + iov_off,
					    to_copy);
		if (ret) {
			copied = ret;
			break;
		}

		iov_off += to_copy;
		vec_off += to_copy;
		copied += to_copy;

		if (vec_off == sg->length) {
			vec_off = 0;
			sg++;
		}
	}

	return copied;
}

/*
 * If the message is still on the send queue, wait until the transport
 * is done with it. This is particularly important for RDMA operations.
 */
void rds_message_wait(struct rds_message *rm)
{
	wait_event_interruptible(rm->m_flush_wait,
			!test_bit(RDS_MSG_MAPPED, &rm->m_flags));
}

void rds_message_unmapped(struct rds_message *rm)
{
	clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
	wake_up_interruptible(&rm->m_flush_wait);
}
EXPORT_SYMBOL_GPL(rds_message_unmapped);
Commit	Line	Data
7875e18e AG	1	/*
	2	* Copyright (c) 2006 Oracle. All rights reserved.
	3	*
	4	* This software is available to you under a choice of one of two
	5	* licenses. You may choose to be licensed under the terms of the GNU
	6	* General Public License (GPL) Version 2, available from the file
	7	* COPYING in the main directory of this source tree, or the
	8	* OpenIB.org BSD license below:
	9	*
	10	* Redistribution and use in source and binary forms, with or
	11	* without modification, are permitted provided that the following
	12	* conditions are met:
	13	*
	14	* - Redistributions of source code must retain the above
	15	* copyright notice, this list of conditions and the following
	16	* disclaimer.
	17	*
	18	* - Redistributions in binary form must reproduce the above
	19	* copyright notice, this list of conditions and the following
	20	* disclaimer in the documentation and/or other materials
	21	* provided with the distribution.
	22	*
	23	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	24	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	25	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	26	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	27	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	28	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	29	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	30	* SOFTWARE.
	31	*
	32	*/
	33	#include <linux/kernel.h>
5a0e3ad6	34	#include <linux/slab.h>
7875e18e AG	35
7875e18e AG	36	#include "rds.h"
7875e18e	37
7875e18e AG	38	static unsigned int rds_exthdr_size[__RDS_EXTHDR_MAX] = {
	39	[RDS_EXTHDR_NONE] = 0,
	40	[RDS_EXTHDR_VERSION] = sizeof(struct rds_ext_header_version),
	41	[RDS_EXTHDR_RDMA] = sizeof(struct rds_ext_header_rdma),
	42	[RDS_EXTHDR_RDMA_DEST] = sizeof(struct rds_ext_header_rdma_dest),
	43	};
	44
	45
	46	void rds_message_addref(struct rds_message *rm)
	47	{
	48	rdsdebug("addref rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
	49	atomic_inc(&rm->m_refcount);
	50	}
616b757a	51	EXPORT_SYMBOL_GPL(rds_message_addref);
7875e18e AG	52
	53	/*
	54	* This relies on dma_map_sg() not touching sg[].page during merging.
	55	*/
	56	static void rds_message_purge(struct rds_message *rm)
	57	{
	58	unsigned long i;
	59
	60	if (unlikely(test_bit(RDS_MSG_PAGEVEC, &rm->m_flags)))
	61	return;
	62
6c7cc6e4 AG	63	for (i = 0; i < rm->data.op_nents; i++) {
6c7cc6e4 AG	64	rdsdebug("putting data page %p\n", (void *)sg_page(&rm->data.op_sg[i]));
7875e18e	65	/* XXX will have to put_page for page refs */
6c7cc6e4	66	__free_page(sg_page(&rm->data.op_sg[i]));
7875e18e	67	}
6c7cc6e4	68	rm->data.op_nents = 0;
7875e18e	69
f8b3aaf2 AG	70	if (rm->rdma.op_active)
	71	rds_rdma_free_op(&rm->rdma);
	72	if (rm->rdma.op_rdma_mr)
	73	rds_mr_put(rm->rdma.op_rdma_mr);
d0ab25a8 AG	74
	75	if (rm->atomic.op_active)
	76	rds_atomic_free_op(&rm->atomic);
	77	if (rm->atomic.op_rdma_mr)
	78	rds_mr_put(rm->atomic.op_rdma_mr);
7875e18e	79	}
7875e18e AG	80
	81	void rds_message_put(struct rds_message *rm)
	82	{
	83	rdsdebug("put rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
	84
	85	if (atomic_dec_and_test(&rm->m_refcount)) {
	86	BUG_ON(!list_empty(&rm->m_sock_item));
	87	BUG_ON(!list_empty(&rm->m_conn_item));
	88	rds_message_purge(rm);
	89
	90	kfree(rm);
	91	}
	92	}
616b757a	93	EXPORT_SYMBOL_GPL(rds_message_put);
7875e18e	94
7875e18e AG	95	void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
	96	__be16 dport, u64 seq)
	97	{
	98	hdr->h_flags = 0;
	99	hdr->h_sport = sport;
	100	hdr->h_dport = dport;
	101	hdr->h_sequence = cpu_to_be64(seq);
	102	hdr->h_exthdr[0] = RDS_EXTHDR_NONE;
	103	}
616b757a	104	EXPORT_SYMBOL_GPL(rds_message_populate_header);
7875e18e AG	105
	106	int rds_message_add_extension(struct rds_header *hdr,
	107	unsigned int type, const void *data, unsigned int len)
	108	{
	109	unsigned int ext_len = sizeof(u8) + len;
	110	unsigned char *dst;
	111
	112	/* For now, refuse to add more than one extension header */
	113	if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE)
	114	return 0;
	115
f64f9e71	116	if (type >= __RDS_EXTHDR_MAX \|\| len != rds_exthdr_size[type])
7875e18e AG	117	return 0;
	118
	119	if (ext_len >= RDS_HEADER_EXT_SPACE)
	120	return 0;
	121	dst = hdr->h_exthdr;
	122
	123	*dst++ = type;
	124	memcpy(dst, data, len);
	125
	126	dst[len] = RDS_EXTHDR_NONE;
	127	return 1;
	128	}
616b757a	129	EXPORT_SYMBOL_GPL(rds_message_add_extension);
7875e18e AG	130
	131	/*
	132	* If a message has extension headers, retrieve them here.
	133	* Call like this:
	134	*
	135	* unsigned int pos = 0;
	136	*
	137	* while (1) {
	138	* buflen = sizeof(buffer);
	139	* type = rds_message_next_extension(hdr, &pos, buffer, &buflen);
	140	* if (type == RDS_EXTHDR_NONE)
	141	* break;
	142	* ...
	143	* }
	144	*/
	145	int rds_message_next_extension(struct rds_header *hdr,
	146	unsigned int pos, void buf, unsigned int *buflen)
	147	{
	148	unsigned int offset, ext_type, ext_len;
	149	u8 *src = hdr->h_exthdr;
	150
	151	offset = *pos;
	152	if (offset >= RDS_HEADER_EXT_SPACE)
	153	goto none;
	154
	155	/* Get the extension type and length. For now, the
	156	* length is implied by the extension type. */
	157	ext_type = src[offset++];
	158
	159	if (ext_type == RDS_EXTHDR_NONE \|\| ext_type >= __RDS_EXTHDR_MAX)
	160	goto none;
	161	ext_len = rds_exthdr_size[ext_type];
	162	if (offset + ext_len > RDS_HEADER_EXT_SPACE)
	163	goto none;
	164
	165	*pos = offset + ext_len;
	166	if (ext_len < *buflen)
	167	*buflen = ext_len;
	168	memcpy(buf, src + offset, *buflen);
	169	return ext_type;
	170
	171	none:
	172	*pos = RDS_HEADER_EXT_SPACE;
	173	*buflen = 0;
	174	return RDS_EXTHDR_NONE;
	175	}
	176
	177	int rds_message_add_version_extension(struct rds_header *hdr, unsigned int version)
	178	{
	179	struct rds_ext_header_version ext_hdr;
	180
	181	ext_hdr.h_version = cpu_to_be32(version);
	182	return rds_message_add_extension(hdr, RDS_EXTHDR_VERSION, &ext_hdr, sizeof(ext_hdr));
	183	}
	184
	185	int rds_message_get_version_extension(struct rds_header hdr, unsigned int version)
	186	{
	187	struct rds_ext_header_version ext_hdr;
	188	unsigned int pos = 0, len = sizeof(ext_hdr);
	189
	190	/* We assume the version extension is the only one present */
	191	if (rds_message_next_extension(hdr, &pos, &ext_hdr, &len) != RDS_EXTHDR_VERSION)
	192	return 0;
	193	*version = be32_to_cpu(ext_hdr.h_version);
194	return 1;
195	}
196
197	int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset)
198	{
199	struct rds_ext_header_rdma_dest ext_hdr;
200
201	ext_hdr.h_rdma_rkey = cpu_to_be32(r_key);
202	ext_hdr.h_rdma_offset = cpu_to_be32(offset);
203	return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr));
204	}
616b757a	205	EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension);
7875e18e	206
fc445084 AG	207	/*
	208	* Each rds_message is allocated with extra space for the scatterlist entries
	209	* rds ops will need. This is to minimize memory allocation count. Then, each rds op
	210	* can grab SGs when initializing its part of the rds_message.
	211	*/
	212	struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp)
7875e18e AG	213	{
	214	struct rds_message *rm;
	215
fc445084	216	rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp);
7875e18e AG	217	if (!rm)
	218	goto out;
	219
fc445084 AG	220	rm->m_used_sgs = 0;
	221	rm->m_total_sgs = extra_len / sizeof(struct scatterlist);
	222
7875e18e AG	223	atomic_set(&rm->m_refcount, 1);
	224	INIT_LIST_HEAD(&rm->m_sock_item);
	225	INIT_LIST_HEAD(&rm->m_conn_item);
	226	spin_lock_init(&rm->m_rs_lock);
c83188dc	227	init_waitqueue_head(&rm->m_flush_wait);
7875e18e AG	228
	229	out:
	230	return rm;
	231	}
	232
fc445084 AG	233	/*
	234	* RDS ops use this to grab SG entries from the rm's sg pool.
	235	*/
	236	struct scatterlist rds_message_alloc_sgs(struct rds_message rm, int nents)
	237	{
	238	struct scatterlist sg_first = (struct scatterlist ) &rm[1];
	239	struct scatterlist *sg_ret;
	240
	241	WARN_ON(rm->m_used_sgs + nents > rm->m_total_sgs);
ee4c7b47	242	WARN_ON(!nents);
fc445084 AG	243
fc445084 AG	244	sg_ret = &sg_first[rm->m_used_sgs];
f4dd96f7	245	sg_init_table(sg_ret, nents);
fc445084 AG	246	rm->m_used_sgs += nents;
	247
	248	return sg_ret;
	249	}
	250
7875e18e AG	251	struct rds_message rds_message_map_pages(unsigned long page_addrs, unsigned int total_len)
	252	{
	253	struct rds_message *rm;
	254	unsigned int i;
ff87e97a AG	255	int num_sgs = ceil(total_len, PAGE_SIZE);
ff87e97a AG	256	int extra_bytes = num_sgs * sizeof(struct scatterlist);
7875e18e	257
f2ec76f2	258	rm = rds_message_alloc(extra_bytes, GFP_NOWAIT);
8690bfa1	259	if (!rm)
7875e18e AG	260	return ERR_PTR(-ENOMEM);
	261
	262	set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
	263	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
6c7cc6e4 AG	264	rm->data.op_nents = ceil(total_len, PAGE_SIZE);
6c7cc6e4 AG	265	rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
7875e18e	266
6c7cc6e4 AG	267	for (i = 0; i < rm->data.op_nents; ++i) {
6c7cc6e4 AG	268	sg_set_page(&rm->data.op_sg[i],
7875e18e AG	269	virt_to_page(page_addrs[i]),
	270	PAGE_SIZE, 0);
	271	}
	272
	273	return rm;
	274	}
	275
fc445084	276	int rds_message_copy_from_user(struct rds_message rm, struct iovec first_iov,
7875e18e AG	277	size_t total_len)
	278	{
	279	unsigned long to_copy;
	280	unsigned long iov_off;
	281	unsigned long sg_off;
7875e18e AG	282	struct iovec *iov;
7875e18e AG	283	struct scatterlist *sg;
fc445084	284	int ret = 0;
7875e18e AG	285
	286	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
	287
	288	/*
	289	* now allocate and copy in the data payload.
	290	*/
6c7cc6e4	291	sg = rm->data.op_sg;
7875e18e AG	292	iov = first_iov;
	293	iov_off = 0;
	294	sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
	295
	296	while (total_len) {
8690bfa1	297	if (!sg_page(sg)) {
7875e18e AG	298	ret = rds_page_remainder_alloc(sg, total_len,
	299	GFP_HIGHUSER);
	300	if (ret)
	301	goto out;
6c7cc6e4	302	rm->data.op_nents++;
7875e18e AG	303	sg_off = 0;
	304	}
	305
	306	while (iov_off == iov->iov_len) {
	307	iov_off = 0;
	308	iov++;
	309	}
	310
	311	to_copy = min(iov->iov_len - iov_off, sg->length - sg_off);
	312	to_copy = min_t(size_t, to_copy, total_len);
	313
	314	rdsdebug("copying %lu bytes from user iov [%p, %zu] + %lu to "
	315	"sg [%p, %u, %u] + %lu\n",
	316	to_copy, iov->iov_base, iov->iov_len, iov_off,
	317	(void *)sg_page(sg), sg->offset, sg->length, sg_off);
	318
	319	ret = rds_page_copy_from_user(sg_page(sg), sg->offset + sg_off,
	320	iov->iov_base + iov_off,
	321	to_copy);
	322	if (ret)
	323	goto out;
	324
	325	iov_off += to_copy;
	326	total_len -= to_copy;
	327	sg_off += to_copy;
	328
	329	if (sg_off == sg->length)
	330	sg++;
	331	}
	332
7875e18e	333	out:
fc445084	334	return ret;
7875e18e AG	335	}
	336
	337	int rds_message_inc_copy_to_user(struct rds_incoming *inc,
	338	struct iovec *first_iov, size_t size)
	339	{
	340	struct rds_message *rm;
	341	struct iovec *iov;
	342	struct scatterlist *sg;
	343	unsigned long to_copy;
	344	unsigned long iov_off;
	345	unsigned long vec_off;
	346	int copied;
	347	int ret;
	348	u32 len;
	349
	350	rm = container_of(inc, struct rds_message, m_inc);
	351	len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
	352
	353	iov = first_iov;
	354	iov_off = 0;
6c7cc6e4	355	sg = rm->data.op_sg;
7875e18e AG	356	vec_off = 0;
	357	copied = 0;
	358
	359	while (copied < size && copied < len) {
	360	while (iov_off == iov->iov_len) {
	361	iov_off = 0;
	362	iov++;
	363	}
	364
	365	to_copy = min(iov->iov_len - iov_off, sg->length - vec_off);
	366	to_copy = min_t(size_t, to_copy, size - copied);
	367	to_copy = min_t(unsigned long, to_copy, len - copied);
	368
	369	rdsdebug("copying %lu bytes to user iov [%p, %zu] + %lu to "
	370	"sg [%p, %u, %u] + %lu\n",
	371	to_copy, iov->iov_base, iov->iov_len, iov_off,
	372	sg_page(sg), sg->offset, sg->length, vec_off);
	373
	374	ret = rds_page_copy_to_user(sg_page(sg), sg->offset + vec_off,
	375	iov->iov_base + iov_off,
	376	to_copy);
	377	if (ret) {
	378	copied = ret;
	379	break;
	380	}
	381
	382	iov_off += to_copy;
	383	vec_off += to_copy;
	384	copied += to_copy;
	385
	386	if (vec_off == sg->length) {
	387	vec_off = 0;
	388	sg++;
	389	}
	390	}
	391
	392	return copied;
	393	}
	394
	395	/*
	396	* If the message is still on the send queue, wait until the transport
	397	* is done with it. This is particularly important for RDMA operations.
	398	*/
	399	void rds_message_wait(struct rds_message *rm)
	400	{
c83188dc	401	wait_event_interruptible(rm->m_flush_wait,
7875e18e AG	402	!test_bit(RDS_MSG_MAPPED, &rm->m_flags));
	403	}
	404
	405	void rds_message_unmapped(struct rds_message *rm)
	406	{
	407	clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
c83188dc	408	wake_up_interruptible(&rm->m_flush_wait);
7875e18e	409	}
616b757a	410	EXPORT_SYMBOL_GPL(rds_message_unmapped);
7875e18e	411