[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_read(&rm->m_refcount) == 0) {
printk(KERN_CRIT "danger refcount zero on %p\n", rm);
WARN_ON(1);
	}
	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_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);

	if (rm->m_used_sgs + nents > rm->m_total_sgs)
		return NULL;

	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);
	if (!rm->data.op_sg)
		return ERR_PTR(-ENOMEM);

	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));
7e3f2952 CM	84	if (atomic_read(&rm->m_refcount) == 0) {
	85	printk(KERN_CRIT "danger refcount zero on %p\n", rm);
	86	WARN_ON(1);
	87	}
7875e18e AG	88	if (atomic_dec_and_test(&rm->m_refcount)) {
	89	BUG_ON(!list_empty(&rm->m_sock_item));
	90	BUG_ON(!list_empty(&rm->m_conn_item));
	91	rds_message_purge(rm);
	92
	93	kfree(rm);
	94	}
	95	}
616b757a	96	EXPORT_SYMBOL_GPL(rds_message_put);
7875e18e	97
7875e18e AG	98	void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
	99	__be16 dport, u64 seq)
	100	{
	101	hdr->h_flags = 0;
	102	hdr->h_sport = sport;
	103	hdr->h_dport = dport;
	104	hdr->h_sequence = cpu_to_be64(seq);
	105	hdr->h_exthdr[0] = RDS_EXTHDR_NONE;
	106	}
616b757a	107	EXPORT_SYMBOL_GPL(rds_message_populate_header);
7875e18e	108
ff51bf84	109	int rds_message_add_extension(struct rds_header *hdr, unsigned int type,
ff51bf84	110	const void *data, unsigned int len)
7875e18e AG	111	{
	112	unsigned int ext_len = sizeof(u8) + len;
	113	unsigned char *dst;
	114
	115	/* For now, refuse to add more than one extension header */
	116	if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE)
	117	return 0;
	118
f64f9e71	119	if (type >= __RDS_EXTHDR_MAX \|\| len != rds_exthdr_size[type])
7875e18e AG	120	return 0;
	121
	122	if (ext_len >= RDS_HEADER_EXT_SPACE)
	123	return 0;
	124	dst = hdr->h_exthdr;
	125
	126	*dst++ = type;
	127	memcpy(dst, data, len);
	128
	129	dst[len] = RDS_EXTHDR_NONE;
	130	return 1;
	131	}
616b757a	132	EXPORT_SYMBOL_GPL(rds_message_add_extension);
7875e18e AG	133
	134	/*
	135	* If a message has extension headers, retrieve them here.
	136	* Call like this:
	137	*
	138	* unsigned int pos = 0;
	139	*
	140	* while (1) {
	141	* buflen = sizeof(buffer);
	142	* type = rds_message_next_extension(hdr, &pos, buffer, &buflen);
	143	* if (type == RDS_EXTHDR_NONE)
	144	* break;
	145	* ...
	146	* }
	147	*/
	148	int rds_message_next_extension(struct rds_header *hdr,
	149	unsigned int pos, void buf, unsigned int *buflen)
	150	{
	151	unsigned int offset, ext_type, ext_len;
	152	u8 *src = hdr->h_exthdr;
	153
	154	offset = *pos;
	155	if (offset >= RDS_HEADER_EXT_SPACE)
	156	goto none;
	157
	158	/* Get the extension type and length. For now, the
	159	* length is implied by the extension type. */
	160	ext_type = src[offset++];
	161
	162	if (ext_type == RDS_EXTHDR_NONE \|\| ext_type >= __RDS_EXTHDR_MAX)
	163	goto none;
	164	ext_len = rds_exthdr_size[ext_type];
	165	if (offset + ext_len > RDS_HEADER_EXT_SPACE)
	166	goto none;
	167
	168	*pos = offset + ext_len;
	169	if (ext_len < *buflen)
	170	*buflen = ext_len;
	171	memcpy(buf, src + offset, *buflen);
	172	return ext_type;
	173
	174	none:
	175	*pos = RDS_HEADER_EXT_SPACE;
	176	*buflen = 0;
	177	return RDS_EXTHDR_NONE;
	178	}
	179
7875e18e AG	180	int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset)
	181	{
	182	struct rds_ext_header_rdma_dest ext_hdr;
	183
	184	ext_hdr.h_rdma_rkey = cpu_to_be32(r_key);
	185	ext_hdr.h_rdma_offset = cpu_to_be32(offset);
	186	return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr));
	187	}
616b757a	188	EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension);
7875e18e	189
fc445084 AG	190	/*
	191	* Each rds_message is allocated with extra space for the scatterlist entries
	192	* rds ops will need. This is to minimize memory allocation count. Then, each rds op
	193	* can grab SGs when initializing its part of the rds_message.
	194	*/
	195	struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp)
7875e18e AG	196	{
	197	struct rds_message *rm;
	198
fc445084	199	rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp);
7875e18e AG	200	if (!rm)
	201	goto out;
	202
fc445084 AG	203	rm->m_used_sgs = 0;
	204	rm->m_total_sgs = extra_len / sizeof(struct scatterlist);
	205
7875e18e AG	206	atomic_set(&rm->m_refcount, 1);
	207	INIT_LIST_HEAD(&rm->m_sock_item);
	208	INIT_LIST_HEAD(&rm->m_conn_item);
	209	spin_lock_init(&rm->m_rs_lock);
c83188dc	210	init_waitqueue_head(&rm->m_flush_wait);
7875e18e AG	211
	212	out:
	213	return rm;
	214	}
	215
fc445084 AG	216	/*
	217	* RDS ops use this to grab SG entries from the rm's sg pool.
	218	*/
	219	struct scatterlist rds_message_alloc_sgs(struct rds_message rm, int nents)
	220	{
	221	struct scatterlist sg_first = (struct scatterlist ) &rm[1];
	222	struct scatterlist *sg_ret;
	223
	224	WARN_ON(rm->m_used_sgs + nents > rm->m_total_sgs);
ee4c7b47	225	WARN_ON(!nents);
fc445084	226
d139ff09 AG	227	if (rm->m_used_sgs + nents > rm->m_total_sgs)
	228	return NULL;
	229
fc445084	230	sg_ret = &sg_first[rm->m_used_sgs];
f4dd96f7	231	sg_init_table(sg_ret, nents);
fc445084 AG	232	rm->m_used_sgs += nents;
	233
	234	return sg_ret;
	235	}
	236
7875e18e AG	237	struct rds_message rds_message_map_pages(unsigned long page_addrs, unsigned int total_len)
	238	{
	239	struct rds_message *rm;
	240	unsigned int i;
ff87e97a AG	241	int num_sgs = ceil(total_len, PAGE_SIZE);
ff87e97a AG	242	int extra_bytes = num_sgs * sizeof(struct scatterlist);
7875e18e	243
f2ec76f2	244	rm = rds_message_alloc(extra_bytes, GFP_NOWAIT);
8690bfa1	245	if (!rm)
7875e18e AG	246	return ERR_PTR(-ENOMEM);
	247
	248	set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
	249	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
6c7cc6e4 AG	250	rm->data.op_nents = ceil(total_len, PAGE_SIZE);
6c7cc6e4 AG	251	rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
d139ff09 AG	252	if (!rm->data.op_sg)
d139ff09 AG	253	return ERR_PTR(-ENOMEM);
7875e18e	254
6c7cc6e4 AG	255	for (i = 0; i < rm->data.op_nents; ++i) {
6c7cc6e4 AG	256	sg_set_page(&rm->data.op_sg[i],
7875e18e AG	257	virt_to_page(page_addrs[i]),
	258	PAGE_SIZE, 0);
	259	}
	260
	261	return rm;
	262	}
	263
fc445084	264	int rds_message_copy_from_user(struct rds_message rm, struct iovec first_iov,
7875e18e AG	265	size_t total_len)
	266	{
	267	unsigned long to_copy;
	268	unsigned long iov_off;
	269	unsigned long sg_off;
7875e18e AG	270	struct iovec *iov;
7875e18e AG	271	struct scatterlist *sg;
fc445084	272	int ret = 0;
7875e18e AG	273
	274	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
	275
	276	/*
	277	* now allocate and copy in the data payload.
	278	*/
6c7cc6e4	279	sg = rm->data.op_sg;
7875e18e AG	280	iov = first_iov;
	281	iov_off = 0;
	282	sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
	283
	284	while (total_len) {
8690bfa1	285	if (!sg_page(sg)) {
7875e18e AG	286	ret = rds_page_remainder_alloc(sg, total_len,
	287	GFP_HIGHUSER);
	288	if (ret)
	289	goto out;
6c7cc6e4	290	rm->data.op_nents++;
7875e18e AG	291	sg_off = 0;
	292	}
	293
	294	while (iov_off == iov->iov_len) {
	295	iov_off = 0;
	296	iov++;
	297	}
	298
	299	to_copy = min(iov->iov_len - iov_off, sg->length - sg_off);
	300	to_copy = min_t(size_t, to_copy, total_len);
	301
	302	rdsdebug("copying %lu bytes from user iov [%p, %zu] + %lu to "
	303	"sg [%p, %u, %u] + %lu\n",
	304	to_copy, iov->iov_base, iov->iov_len, iov_off,
	305	(void *)sg_page(sg), sg->offset, sg->length, sg_off);
	306
	307	ret = rds_page_copy_from_user(sg_page(sg), sg->offset + sg_off,
	308	iov->iov_base + iov_off,
	309	to_copy);
	310	if (ret)
	311	goto out;
	312
	313	iov_off += to_copy;
	314	total_len -= to_copy;
	315	sg_off += to_copy;
	316
	317	if (sg_off == sg->length)
	318	sg++;
	319	}
	320
7875e18e	321	out:
fc445084	322	return ret;
7875e18e AG	323	}
	324
	325	int rds_message_inc_copy_to_user(struct rds_incoming *inc,
	326	struct iovec *first_iov, size_t size)
	327	{
	328	struct rds_message *rm;
	329	struct iovec *iov;
	330	struct scatterlist *sg;
	331	unsigned long to_copy;
	332	unsigned long iov_off;
	333	unsigned long vec_off;
	334	int copied;
	335	int ret;
	336	u32 len;
	337
	338	rm = container_of(inc, struct rds_message, m_inc);
	339	len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
	340
	341	iov = first_iov;
	342	iov_off = 0;
6c7cc6e4	343	sg = rm->data.op_sg;
7875e18e AG	344	vec_off = 0;
	345	copied = 0;
	346
	347	while (copied < size && copied < len) {
	348	while (iov_off == iov->iov_len) {
	349	iov_off = 0;
	350	iov++;
	351	}
	352
	353	to_copy = min(iov->iov_len - iov_off, sg->length - vec_off);
	354	to_copy = min_t(size_t, to_copy, size - copied);
	355	to_copy = min_t(unsigned long, to_copy, len - copied);
	356
	357	rdsdebug("copying %lu bytes to user iov [%p, %zu] + %lu to "
	358	"sg [%p, %u, %u] + %lu\n",
	359	to_copy, iov->iov_base, iov->iov_len, iov_off,
	360	sg_page(sg), sg->offset, sg->length, vec_off);
	361
	362	ret = rds_page_copy_to_user(sg_page(sg), sg->offset + vec_off,
	363	iov->iov_base + iov_off,
	364	to_copy);
	365	if (ret) {
	366	copied = ret;
	367	break;
	368	}
	369
	370	iov_off += to_copy;
	371	vec_off += to_copy;
	372	copied += to_copy;
	373
	374	if (vec_off == sg->length) {
	375	vec_off = 0;
	376	sg++;
	377	}
	378	}
	379
	380	return copied;
	381	}
	382
	383	/*
	384	* If the message is still on the send queue, wait until the transport
	385	* is done with it. This is particularly important for RDMA operations.
	386	*/
	387	void rds_message_wait(struct rds_message *rm)
	388	{
c83188dc	389	wait_event_interruptible(rm->m_flush_wait,
7875e18e AG	390	!test_bit(RDS_MSG_MAPPED, &rm->m_flags));
	391	}
	392
	393	void rds_message_unmapped(struct rds_message *rm)
	394	{
	395	clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
c83188dc	396	wake_up_interruptible(&rm->m_flush_wait);
7875e18e	397	}
616b757a	398	EXPORT_SYMBOL_GPL(rds_message_unmapped);
7875e18e	399