/*
* Copyright (c) 2016 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 "ib_mr.h"
static inline void
rds_transition_frwr_state(struct rds_ib_mr *ibmr,
enum rds_ib_fr_state old_state,
enum rds_ib_fr_state new_state)
{
if (cmpxchg(&ibmr->u.frmr.fr_state,
old_state, new_state) == old_state &&
old_state == FRMR_IS_INUSE) {
/* enforce order of ibmr->u.frmr.fr_state update
* before decrementing i_fastreg_inuse_count
*/
smp_mb__before_atomic();
atomic_dec(&ibmr->ic->i_fastreg_inuse_count);
if (waitqueue_active(&rds_ib_ring_empty_wait))
wake_up(&rds_ib_ring_empty_wait);
}
}
static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev,
int npages)
{
struct rds_ib_mr_pool *pool;
struct rds_ib_mr *ibmr = NULL;
struct rds_ib_frmr *frmr;
int err = 0;
if (npages <= RDS_MR_8K_MSG_SIZE)
pool = rds_ibdev->mr_8k_pool;
else
pool = rds_ibdev->mr_1m_pool;
ibmr = rds_ib_try_reuse_ibmr(pool);
if (ibmr)
return ibmr;
ibmr = kzalloc_node(sizeof(*ibmr), GFP_KERNEL,
rdsibdev_to_node(rds_ibdev));
if (!ibmr) {
err = -ENOMEM;
goto out_no_cigar;
}
frmr = &ibmr->u.frmr;
frmr->mr = ib_alloc_mr(rds_ibdev->pd, IB_MR_TYPE_MEM_REG,
pool->max_pages);
if (IS_ERR(frmr->mr)) {
pr_warn("RDS/IB: %s failed to allocate MR", __func__);
err = PTR_ERR(frmr->mr);
goto out_no_cigar;
}
ibmr->pool = pool;
if (pool->pool_type == RDS_IB_MR_8K_POOL)
rds_ib_stats_inc(s_ib_rdma_mr_8k_alloc);
else
rds_ib_stats_inc(s_ib_rdma_mr_1m_alloc);
if (atomic_read(&pool->item_count) > pool->max_items_soft)
pool->max_items_soft = pool->max_items;
frmr->fr_state = FRMR_IS_FREE;
init_waitqueue_head(&frmr->fr_inv_done);
init_waitqueue_head(&frmr->fr_reg_done);
return ibmr;
out_no_cigar:
kfree(ibmr);
atomic_dec(&pool->item_count);
return ERR_PTR(err);
}
static void rds_ib_free_frmr(struct rds_ib_mr *ibmr, bool drop)
{
struct rds_ib_mr_pool *pool = ibmr->pool;
if (drop)
llist_add(&ibmr->llnode, &pool->drop_list);
else
llist_add(&ibmr->llnode, &pool->free_list);
atomic_add(ibmr->sg_len, &pool->free_pinned);
atomic_inc(&pool->dirty_count);
/* If we've pinned too many pages, request a flush */
if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
atomic_read(&pool->dirty_count) >= pool->max_items / 5)
queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);
}
static int rds_ib_post_reg_frmr(struct rds_ib_mr *ibmr)
{
struct rds_ib_frmr *frmr = &ibmr->u.frmr;
struct ib_reg_wr reg_wr;
int ret, off = 0;
while (atomic_dec_return(&ibmr->ic->i_fastreg_wrs) <= 0) {
atomic_inc(&ibmr->ic->i_fastreg_wrs);
cpu_relax();
}
ret = ib_map_mr_sg_zbva(frmr->mr, ibmr->sg, ibmr->sg_dma_len,
&off, PAGE_SIZE);
if (unlikely(ret != ibmr->sg_dma_len))
return ret < 0 ? ret : -EINVAL;
if (cmpxchg(&frmr->fr_state,
FRMR_IS_FREE, FRMR_IS_INUSE) != FRMR_IS_FREE)
return -EBUSY;
atomic_inc(&ibmr->ic->i_fastreg_inuse_count);
/* Perform a WR for the fast_reg_mr. Each individual page
* in the sg list is added to the fast reg page list and placed
* inside the fast_reg_mr WR. The key used is a rolling 8bit
* counter, which should guarantee uniqueness.
*/
ib_update_fast_reg_key(frmr->mr, ibmr->remap_count++);
frmr->fr_reg = true;
memset(®_wr, 0, sizeof(reg_wr));
reg_wr.wr.wr_id = (unsigned long)(void *)ibmr;
reg_wr.wr.opcode = IB_WR_REG_MR;
reg_wr.wr.num_sge = 0;
reg_wr.mr = frmr->mr;
reg_wr.key = frmr->mr->rkey;
reg_wr.access = IB_ACCESS_LOCAL_WRITE |
IB_ACCESS_REMOTE_READ |
IB_ACCESS_REMOTE_WRITE;
reg_wr.wr.send_flags = IB_SEND_SIGNALED;
ret = ib_post_send(ibmr->ic->i_cm_id->qp, ®_wr.wr, NULL);
if (unlikely(ret)) {
/* Failure here can be because of -ENOMEM as well */
rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
atomic_inc(&ibmr->ic->i_fastreg_wrs);
if (printk_ratelimit())
pr_warn("RDS/IB: %s returned error(%d)\n",
__func__, ret);
goto out;
}
/* Wait for the registration to complete in order to prevent an invalid
* access error resulting from a race between the memory region already
* being accessed while registration is still pending.
*/
wait_event(frmr->fr_reg_done, !frmr->fr_reg);
out:
return ret;
}
static int rds_ib_map_frmr(struct rds_ib_device *rds_ibdev,
struct rds_ib_mr_pool *pool,
struct rds_ib_mr *ibmr,
struct scatterlist *sg, unsigned int sg_len)
{
struct ib_device *dev = rds_ibdev->dev;
struct rds_ib_frmr *frmr = &ibmr->u.frmr;
int i;
u32 len;
int ret = 0;
/* We want to teardown old ibmr values here and fill it up with
* new sg values
*/
rds_ib_teardown_mr(ibmr);
ibmr->sg = sg;
ibmr->sg_len = sg_len;
ibmr->sg_dma_len = 0;
frmr->sg_byte_len = 0;
WARN_ON(ibmr->sg_dma_len);
ibmr->sg_dma_len = ib_dma_map_sg(dev, ibmr->sg, ibmr->sg_len,
DMA_BIDIRECTIONAL);
if (unlikely(!ibmr->sg_dma_len)) {
pr_warn("RDS/IB: %s failed!\n", __func__);
return -EBUSY;
}
frmr->sg_byte_len = 0;
frmr->dma_npages = 0;
len = 0;
ret = -EINVAL;
for (i = 0; i < ibmr->sg_dma_len; ++i) {
unsigned int dma_len = sg_dma_len(&ibmr->sg[i]);
u64 dma_addr = sg_dma_address(&ibmr->sg[i]);
frmr->sg_byte_len += dma_len;
if (dma_addr & ~PAGE_MASK) {
if (i > 0)
goto out_unmap;
else
++frmr->dma_npages;
}
if ((dma_addr + dma_len) & ~PAGE_MASK) {
if (i < ibmr->sg_dma_len - 1)
goto out_unmap;
else
++frmr->dma_npages;
}
len += dma_len;
}
frmr->dma_npages += len >> PAGE_SHIFT;
if (frmr->dma_npages > ibmr->pool->max_pages) {
ret = -EMSGSIZE;
goto out_unmap;
}
ret = rds_ib_post_reg_frmr(ibmr);
if (ret)
goto out_unmap;
if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
rds_ib_stats_inc(s_ib_rdma_mr_8k_used);
else
rds_ib_stats_inc(s_ib_rdma_mr_1m_used);
return ret;
out_unmap:
ib_dma_unmap_sg(rds_ibdev->dev, ibmr->sg, ibmr->sg_len,
DMA_BIDIRECTIONAL);
ibmr->sg_dma_len = 0;
return ret;
}
static int rds_ib_post_inv(struct rds_ib_mr *ibmr)
{
struct ib_send_wr *s_wr;
struct rds_ib_frmr *frmr = &ibmr->u.frmr;
struct rdma_cm_id *i_cm_id = ibmr->ic->i_cm_id;
int ret = -EINVAL;
if (!i_cm_id || !i_cm_id->qp || !frmr->mr)
goto out;
if (frmr->fr_state != FRMR_IS_INUSE)
goto out;
while (atomic_dec_return(&ibmr->ic->i_fastreg_wrs) <= 0) {
atomic_inc(&ibmr->ic->i_fastreg_wrs);
cpu_relax();
}
frmr->fr_inv = true;
s_wr = &frmr->fr_wr;
memset(s_wr, 0, sizeof(*s_wr));
s_wr->wr_id = (unsigned long)(void *)ibmr;
s_wr->opcode = IB_WR_LOCAL_INV;
s_wr->ex.invalidate_rkey = frmr->mr->rkey;
s_wr->send_flags = IB_SEND_SIGNALED;
ret = ib_post_send(i_cm_id->qp, s_wr, NULL);
if (unlikely(ret)) {
rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
frmr->fr_inv = false;
/* enforce order of frmr->fr_inv update
* before incrementing i_fastreg_wrs
*/
smp_mb__before_atomic();
atomic_inc(&ibmr->ic->i_fastreg_wrs);
pr_err("RDS/IB: %s returned error(%d)\n", __func__, ret);
goto out;
}
/* Wait for the FRMR_IS_FREE (or FRMR_IS_STALE) transition in order to
* 1) avoid a silly bouncing between "clean_list" and "drop_list"
* triggered by function "rds_ib_reg_frmr" as it is releases frmr
* regions whose state is not "FRMR_IS_FREE" right away.
* 2) prevents an invalid access error in a race
* from a pending "IB_WR_LOCAL_INV" operation
* with a teardown ("dma_unmap_sg", "put_page")
* and de-registration ("ib_dereg_mr") of the corresponding
* memory region.
*/
wait_event(frmr->fr_inv_done, frmr->fr_state != FRMR_IS_INUSE);
out:
return ret;
}
void rds_ib_mr_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc)
{
struct rds_ib_mr *ibmr = (void *)(unsigned long)wc->wr_id;
struct rds_ib_frmr *frmr = &ibmr->u.frmr;
if (wc->status != IB_WC_SUCCESS) {
rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
if (rds_conn_up(ic->conn))
rds_ib_conn_error(ic->conn,
"frmr completion <%pI4,%pI4> status %u(%s), vendor_err 0x%x, disconnecting and reconnecting\n",
&ic->conn->c_laddr,
&ic->conn->c_faddr,
wc->status,
ib_wc_status_msg(wc->status),
wc->vendor_err);
}
if (frmr->fr_inv) {
rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_FREE);
frmr->fr_inv = false;
wake_up(&frmr->fr_inv_done);
}
if (frmr->fr_reg) {
frmr->fr_reg = false;
wake_up(&frmr->fr_reg_done);
}
/* enforce order of frmr->{fr_reg,fr_inv} update
* before incrementing i_fastreg_wrs
*/
smp_mb__before_atomic();
atomic_inc(&ic->i_fastreg_wrs);
}
void rds_ib_unreg_frmr(struct list_head *list, unsigned int *nfreed,
unsigned long *unpinned, unsigned int goal)
{
struct rds_ib_mr *ibmr, *next;
struct rds_ib_frmr *frmr;
int ret = 0, ret2;
unsigned int freed = *nfreed;
/* String all ib_mr's onto one list and hand them to ib_unmap_fmr */
list_for_each_entry(ibmr, list, unmap_list) {
if (ibmr->sg_dma_len) {
ret2 = rds_ib_post_inv(ibmr);
if (ret2 && !ret)
ret = ret2;
}
}
if (ret)
pr_warn("RDS/IB: %s failed (err=%d)\n", __func__, ret);
/* Now we can destroy the DMA mapping and unpin any pages */
list_for_each_entry_safe(ibmr, next, list, unmap_list) {
*unpinned += ibmr->sg_len;
frmr = &ibmr->u.frmr;
__rds_ib_teardown_mr(ibmr);
if (freed < goal || frmr->fr_state == FRMR_IS_STALE) {
/* Don't de-allocate if the MR is not free yet */
if (frmr->fr_state == FRMR_IS_INUSE)
continue;
if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
rds_ib_stats_inc(s_ib_rdma_mr_8k_free);
else
rds_ib_stats_inc(s_ib_rdma_mr_1m_free);
list_del(&ibmr->unmap_list);
if (frmr->mr)
ib_dereg_mr(frmr->mr);
kfree(ibmr);
freed++;
}
}
*nfreed = freed;
}
struct rds_ib_mr *rds_ib_reg_frmr(struct rds_ib_device *rds_ibdev,
struct rds_ib_connection *ic,
struct scatterlist *sg,
unsigned long nents, u32 *key)
{
struct rds_ib_mr *ibmr = NULL;
struct rds_ib_frmr *frmr;
int ret;
if (!ic) {
/* TODO: Add FRWR support for RDS_GET_MR using proxy qp*/
return ERR_PTR(-EOPNOTSUPP);
}
do {
if (ibmr)
rds_ib_free_frmr(ibmr, true);
ibmr = rds_ib_alloc_frmr(rds_ibdev, nents);
if (IS_ERR(ibmr))
return ibmr;
frmr = &ibmr->u.frmr;
} while (frmr->fr_state != FRMR_IS_FREE);
ibmr->ic = ic;
ibmr->device = rds_ibdev;
ret = rds_ib_map_frmr(rds_ibdev, ibmr->pool, ibmr, sg, nents);
if (ret == 0) {
*key = frmr->mr->rkey;
} else {
rds_ib_free_frmr(ibmr, false);
ibmr = ERR_PTR(ret);
}
return ibmr;
}
void rds_ib_free_frmr_list(struct rds_ib_mr *ibmr)
{
struct rds_ib_mr_pool *pool = ibmr->pool;
struct rds_ib_frmr *frmr = &ibmr->u.frmr;
if (frmr->fr_state == FRMR_IS_STALE)
llist_add(&ibmr->llnode, &pool->drop_list);
else
llist_add(&ibmr->llnode, &pool->free_list);
}
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