[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_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));
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 AG	108
	109	int rds_message_add_extension(struct rds_header *hdr,
	110	unsigned int type, const void *data, unsigned int len)
	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
	180	int rds_message_add_version_extension(struct rds_header *hdr, unsigned int version)
	181	{
	182	struct rds_ext_header_version ext_hdr;
	183
	184	ext_hdr.h_version = cpu_to_be32(version);
	185	return rds_message_add_extension(hdr, RDS_EXTHDR_VERSION, &ext_hdr, sizeof(ext_hdr));
	186	}
	187
	188	int rds_message_get_version_extension(struct rds_header hdr, unsigned int version)
	189	{
	190	struct rds_ext_header_version ext_hdr;
	191	unsigned int pos = 0, len = sizeof(ext_hdr);
	192
	193	/* We assume the version extension is the only one present */
	194	if (rds_message_next_extension(hdr, &pos, &ext_hdr, &len) != RDS_EXTHDR_VERSION)
	195	return 0;
	196	*version = be32_to_cpu(ext_hdr.h_version);
197	return 1;
198	}
199
200	int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset)
201	{
202	struct rds_ext_header_rdma_dest ext_hdr;
203
204	ext_hdr.h_rdma_rkey = cpu_to_be32(r_key);
205	ext_hdr.h_rdma_offset = cpu_to_be32(offset);
206	return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr));
207	}
616b757a	208	EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension);
7875e18e	209
fc445084 AG	210	/*
	211	* Each rds_message is allocated with extra space for the scatterlist entries
	212	* rds ops will need. This is to minimize memory allocation count. Then, each rds op
	213	* can grab SGs when initializing its part of the rds_message.
	214	*/
	215	struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp)
7875e18e AG	216	{
	217	struct rds_message *rm;
	218
fc445084	219	rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp);
7875e18e AG	220	if (!rm)
	221	goto out;
	222
fc445084 AG	223	rm->m_used_sgs = 0;
	224	rm->m_total_sgs = extra_len / sizeof(struct scatterlist);
	225
7875e18e AG	226	atomic_set(&rm->m_refcount, 1);
	227	INIT_LIST_HEAD(&rm->m_sock_item);
	228	INIT_LIST_HEAD(&rm->m_conn_item);
	229	spin_lock_init(&rm->m_rs_lock);
c83188dc	230	init_waitqueue_head(&rm->m_flush_wait);
7875e18e AG	231
	232	out:
	233	return rm;
	234	}
	235
fc445084 AG	236	/*
	237	* RDS ops use this to grab SG entries from the rm's sg pool.
	238	*/
	239	struct scatterlist rds_message_alloc_sgs(struct rds_message rm, int nents)
	240	{
	241	struct scatterlist sg_first = (struct scatterlist ) &rm[1];
	242	struct scatterlist *sg_ret;
	243
	244	WARN_ON(rm->m_used_sgs + nents > rm->m_total_sgs);
ee4c7b47	245	WARN_ON(!nents);
fc445084 AG	246
fc445084 AG	247	sg_ret = &sg_first[rm->m_used_sgs];
f4dd96f7	248	sg_init_table(sg_ret, nents);
fc445084 AG	249	rm->m_used_sgs += nents;
	250
	251	return sg_ret;
	252	}
	253
7875e18e AG	254	struct rds_message rds_message_map_pages(unsigned long page_addrs, unsigned int total_len)
	255	{
	256	struct rds_message *rm;
	257	unsigned int i;
ff87e97a AG	258	int num_sgs = ceil(total_len, PAGE_SIZE);
ff87e97a AG	259	int extra_bytes = num_sgs * sizeof(struct scatterlist);
7875e18e	260
f2ec76f2	261	rm = rds_message_alloc(extra_bytes, GFP_NOWAIT);
8690bfa1	262	if (!rm)
7875e18e AG	263	return ERR_PTR(-ENOMEM);
	264
	265	set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
	266	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
6c7cc6e4 AG	267	rm->data.op_nents = ceil(total_len, PAGE_SIZE);
6c7cc6e4 AG	268	rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
7875e18e	269
6c7cc6e4 AG	270	for (i = 0; i < rm->data.op_nents; ++i) {
6c7cc6e4 AG	271	sg_set_page(&rm->data.op_sg[i],
7875e18e AG	272	virt_to_page(page_addrs[i]),
	273	PAGE_SIZE, 0);
	274	}
	275
	276	return rm;
	277	}
	278
fc445084	279	int rds_message_copy_from_user(struct rds_message rm, struct iovec first_iov,
7875e18e AG	280	size_t total_len)
	281	{
	282	unsigned long to_copy;
	283	unsigned long iov_off;
	284	unsigned long sg_off;
7875e18e AG	285	struct iovec *iov;
7875e18e AG	286	struct scatterlist *sg;
fc445084	287	int ret = 0;
7875e18e AG	288
	289	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
	290
	291	/*
	292	* now allocate and copy in the data payload.
	293	*/
6c7cc6e4	294	sg = rm->data.op_sg;
7875e18e AG	295	iov = first_iov;
	296	iov_off = 0;
	297	sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
	298
	299	while (total_len) {
8690bfa1	300	if (!sg_page(sg)) {
7875e18e AG	301	ret = rds_page_remainder_alloc(sg, total_len,
	302	GFP_HIGHUSER);
	303	if (ret)
	304	goto out;
6c7cc6e4	305	rm->data.op_nents++;
7875e18e AG	306	sg_off = 0;
	307	}
	308
	309	while (iov_off == iov->iov_len) {
	310	iov_off = 0;
	311	iov++;
	312	}
	313
	314	to_copy = min(iov->iov_len - iov_off, sg->length - sg_off);
	315	to_copy = min_t(size_t, to_copy, total_len);
	316
	317	rdsdebug("copying %lu bytes from user iov [%p, %zu] + %lu to "
	318	"sg [%p, %u, %u] + %lu\n",
	319	to_copy, iov->iov_base, iov->iov_len, iov_off,
	320	(void *)sg_page(sg), sg->offset, sg->length, sg_off);
	321
	322	ret = rds_page_copy_from_user(sg_page(sg), sg->offset + sg_off,
	323	iov->iov_base + iov_off,
	324	to_copy);
	325	if (ret)
	326	goto out;
	327
	328	iov_off += to_copy;
	329	total_len -= to_copy;
	330	sg_off += to_copy;
	331
	332	if (sg_off == sg->length)
	333	sg++;
	334	}
	335
7875e18e	336	out:
fc445084	337	return ret;
7875e18e AG	338	}
	339
	340	int rds_message_inc_copy_to_user(struct rds_incoming *inc,
	341	struct iovec *first_iov, size_t size)
	342	{
	343	struct rds_message *rm;
	344	struct iovec *iov;
	345	struct scatterlist *sg;
	346	unsigned long to_copy;
	347	unsigned long iov_off;
	348	unsigned long vec_off;
	349	int copied;
	350	int ret;
	351	u32 len;
	352
	353	rm = container_of(inc, struct rds_message, m_inc);
	354	len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
	355
	356	iov = first_iov;
	357	iov_off = 0;
6c7cc6e4	358	sg = rm->data.op_sg;
7875e18e AG	359	vec_off = 0;
	360	copied = 0;
	361
	362	while (copied < size && copied < len) {
	363	while (iov_off == iov->iov_len) {
	364	iov_off = 0;
	365	iov++;
	366	}
	367
	368	to_copy = min(iov->iov_len - iov_off, sg->length - vec_off);
	369	to_copy = min_t(size_t, to_copy, size - copied);
	370	to_copy = min_t(unsigned long, to_copy, len - copied);
	371
	372	rdsdebug("copying %lu bytes to user iov [%p, %zu] + %lu to "
	373	"sg [%p, %u, %u] + %lu\n",
	374	to_copy, iov->iov_base, iov->iov_len, iov_off,
	375	sg_page(sg), sg->offset, sg->length, vec_off);
	376
	377	ret = rds_page_copy_to_user(sg_page(sg), sg->offset + vec_off,
	378	iov->iov_base + iov_off,
	379	to_copy);
	380	if (ret) {
	381	copied = ret;
	382	break;
	383	}
	384
	385	iov_off += to_copy;
	386	vec_off += to_copy;
	387	copied += to_copy;
	388
	389	if (vec_off == sg->length) {
	390	vec_off = 0;
	391	sg++;
	392	}
	393	}
	394
	395	return copied;
	396	}
	397
	398	/*
	399	* If the message is still on the send queue, wait until the transport
	400	* is done with it. This is particularly important for RDMA operations.
	401	*/
	402	void rds_message_wait(struct rds_message *rm)
	403	{
c83188dc	404	wait_event_interruptible(rm->m_flush_wait,
7875e18e AG	405	!test_bit(RDS_MSG_MAPPED, &rm->m_flags));
	406	}
	407
	408	void rds_message_unmapped(struct rds_message *rm)
	409	{
	410	clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
c83188dc	411	wake_up_interruptible(&rm->m_flush_wait);
7875e18e	412	}
616b757a	413	EXPORT_SYMBOL_GPL(rds_message_unmapped);
7875e18e	414