/*
* Copyright (c) 2006, 2020 Oracle and/or its affiliates.
*
* 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 <linux/export.h>
#include <linux/skbuff.h>
#include <linux/list.h>
#include <linux/errqueue.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),
[RDS_EXTHDR_NPATHS] = sizeof(u16),
[RDS_EXTHDR_GEN_NUM] = sizeof(u32),
};
void rds_message_addref(struct rds_message *rm)
{
rdsdebug("addref rm %p ref %d\n", rm, refcount_read(&rm->m_refcount));
refcount_inc(&rm->m_refcount);
}
EXPORT_SYMBOL_GPL(rds_message_addref);
static inline bool rds_zcookie_add(struct rds_msg_zcopy_info *info, u32 cookie)
{
struct rds_zcopy_cookies *ck = &info->zcookies;
int ncookies = ck->num;
if (ncookies == RDS_MAX_ZCOOKIES)
return false;
ck->cookies[ncookies] = cookie;
ck->num = ++ncookies;
return true;
}
static struct rds_msg_zcopy_info *rds_info_from_znotifier(struct rds_znotifier *znotif)
{
return container_of(znotif, struct rds_msg_zcopy_info, znotif);
}
void rds_notify_msg_zcopy_purge(struct rds_msg_zcopy_queue *q)
{
unsigned long flags;
LIST_HEAD(copy);
struct rds_msg_zcopy_info *info, *tmp;
spin_lock_irqsave(&q->lock, flags);
list_splice(&q->zcookie_head, ©);
INIT_LIST_HEAD(&q->zcookie_head);
spin_unlock_irqrestore(&q->lock, flags);
list_for_each_entry_safe(info, tmp, ©, rs_zcookie_next) {
list_del(&info->rs_zcookie_next);
kfree(info);
}
}
static void rds_rm_zerocopy_callback(struct rds_sock *rs,
struct rds_znotifier *znotif)
{
struct rds_msg_zcopy_info *info;
struct rds_msg_zcopy_queue *q;
u32 cookie = znotif->z_cookie;
struct rds_zcopy_cookies *ck;
struct list_head *head;
unsigned long flags;
mm_unaccount_pinned_pages(&znotif->z_mmp);
q = &rs->rs_zcookie_queue;
spin_lock_irqsave(&q->lock, flags);
head = &q->zcookie_head;
if (!list_empty(head)) {
info = list_first_entry(head, struct rds_msg_zcopy_info,
rs_zcookie_next);
if (rds_zcookie_add(info, cookie)) {
spin_unlock_irqrestore(&q->lock, flags);
kfree(rds_info_from_znotifier(znotif));
/* caller invokes rds_wake_sk_sleep() */
return;
}
}
info = rds_info_from_znotifier(znotif);
ck = &info->zcookies;
memset(ck, 0, sizeof(*ck));
WARN_ON(!rds_zcookie_add(info, cookie));
list_add_tail(&info->rs_zcookie_next, &q->zcookie_head);
spin_unlock_irqrestore(&q->lock, flags);
/* caller invokes rds_wake_sk_sleep() */
}
/*
* This relies on dma_map_sg() not touching sg[].page during merging.
*/
static void rds_message_purge(struct rds_message *rm)
{
unsigned long i, flags;
bool zcopy = false;
if (unlikely(test_bit(RDS_MSG_PAGEVEC, &rm->m_flags)))
return;
spin_lock_irqsave(&rm->m_rs_lock, flags);
if (rm->m_rs) {
struct rds_sock *rs = rm->m_rs;
if (rm->data.op_mmp_znotifier) {
zcopy = true;
rds_rm_zerocopy_callback(rs, rm->data.op_mmp_znotifier);
rds_wake_sk_sleep(rs);
rm->data.op_mmp_znotifier = NULL;
}
sock_put(rds_rs_to_sk(rs));
rm->m_rs = NULL;
}
spin_unlock_irqrestore(&rm->m_rs_lock, flags);
for (i = 0; i < rm->data.op_nents; i++) {
/* XXX will have to put_page for page refs */
if (!zcopy)
__free_page(sg_page(&rm->data.op_sg[i]));
else
put_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)
kref_put(&rm->rdma.op_rdma_mr->r_kref, __rds_put_mr_final);
if (rm->atomic.op_active)
rds_atomic_free_op(&rm->atomic);
if (rm->atomic.op_rdma_mr)
kref_put(&rm->atomic.op_rdma_mr->r_kref, __rds_put_mr_final);
}
void rds_message_put(struct rds_message *rm)
{
rdsdebug("put rm %p ref %d\n", rm, refcount_read(&rm->m_refcount));
WARN(!refcount_read(&rm->m_refcount), "danger refcount zero on %p\n", rm);
if (refcount_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;
if (extra_len > KMALLOC_MAX_SIZE - sizeof(struct rds_message))
return NULL;
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);
refcount_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;
if (nents <= 0) {
pr_warn("rds: alloc sgs failed! nents <= 0\n");
return ERR_PTR(-EINVAL);
}
if (rm->m_used_sgs + nents > rm->m_total_sgs) {
pr_warn("rds: alloc sgs failed! total %d used %d nents %d\n",
rm->m_total_sgs, rm->m_used_sgs, nents);
return ERR_PTR(-ENOMEM);
}
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 = DIV_ROUND_UP(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 = DIV_ROUND_UP(total_len, PAGE_SIZE);
rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
if (IS_ERR(rm->data.op_sg)) {
void *err = ERR_CAST(rm->data.op_sg);
rds_message_put(rm);
return err;
}
for (i = 0; i < rm->data.op_nents; ++i) {
sg_set_page(&rm->data.op_sg[i],
virt_to_page((void *)page_addrs[i]),
PAGE_SIZE, 0);
}
return rm;
}
static int rds_message_zcopy_from_user(struct rds_message *rm, struct iov_iter *from)
{
struct scatterlist *sg;
int ret = 0;
int length = iov_iter_count(from);
struct rds_msg_zcopy_info *info;
rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from));
/*
* now allocate and copy in the data payload.
*/
sg = rm->data.op_sg;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
INIT_LIST_HEAD(&info->rs_zcookie_next);
rm->data.op_mmp_znotifier = &info->znotif;
if (mm_account_pinned_pages(&rm->data.op_mmp_znotifier->z_mmp,
length)) {
ret = -ENOMEM;
goto err;
}
while (iov_iter_count(from)) {
struct page *pages;
size_t start;
ssize_t copied;
copied = iov_iter_get_pages2(from, &pages, PAGE_SIZE,
1, &start);
if (copied < 0) {
struct mmpin *mmp;
int i;
for (i = 0; i < rm->data.op_nents; i++)
put_page(sg_page(&rm->data.op_sg[i]));
mmp = &rm->data.op_mmp_znotifier->z_mmp;
mm_unaccount_pinned_pages(mmp);
ret = -EFAULT;
goto err;
}
length -= copied;
sg_set_page(sg, pages, copied, start);
rm->data.op_nents++;
sg++;
}
WARN_ON_ONCE(length != 0);
return ret;
err:
kfree(info);
rm->data.op_mmp_znotifier = NULL;
return ret;
}
int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from,
bool zcopy)
{
unsigned long to_copy, nbytes;
unsigned long sg_off;
struct scatterlist *sg;
int ret = 0;
rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from));
/* now allocate and copy in the data payload. */
sg = rm->data.op_sg;
sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
if (zcopy)
return rds_message_zcopy_from_user(rm, from);
while (iov_iter_count(from)) {
if (!sg_page(sg)) {
ret = rds_page_remainder_alloc(sg, iov_iter_count(from),
GFP_HIGHUSER);
if (ret)
return ret;
rm->data.op_nents++;
sg_off = 0;
}
to_copy = min_t(unsigned long, iov_iter_count(from),
sg->length - sg_off);
rds_stats_add(s_copy_from_user, to_copy);
nbytes = copy_page_from_iter(sg_page(sg), sg->offset + sg_off,
to_copy, from);
if (nbytes != to_copy)
return -EFAULT;
sg_off += to_copy;
if (sg_off == sg->length)
sg++;
}
return ret;
}
int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
{
struct rds_message *rm;
struct scatterlist *sg;
unsigned long to_copy;
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);
sg = rm->data.op_sg;
vec_off = 0;
copied = 0;
while (iov_iter_count(to) && copied < len) {
to_copy = min_t(unsigned long, iov_iter_count(to),
sg->length - vec_off);
to_copy = min_t(unsigned long, to_copy, len - copied);
rds_stats_add(s_copy_to_user, to_copy);
ret = copy_page_to_iter(sg_page(sg), sg->offset + vec_off,
to_copy, to);
if (ret != to_copy)
return -EFAULT;
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);
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