/*
* 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 <linux/ratelimit.h>
#include "rds.h"
#include "iw.h"
/*
* This is stored as mr->r_trans_private.
*/
struct rds_iw_mr {
struct rds_iw_device *device;
struct rds_iw_mr_pool *pool;
struct rdma_cm_id *cm_id;
struct ib_mr *mr;
struct ib_fast_reg_page_list *page_list;
struct rds_iw_mapping mapping;
unsigned char remap_count;
};
/*
* Our own little MR pool
*/
struct rds_iw_mr_pool {
struct rds_iw_device *device; /* back ptr to the device that owns us */
struct mutex flush_lock; /* serialize fmr invalidate */
struct work_struct flush_worker; /* flush worker */
spinlock_t list_lock; /* protect variables below */
atomic_t item_count; /* total # of MRs */
atomic_t dirty_count; /* # dirty of MRs */
struct list_head dirty_list; /* dirty mappings */
struct list_head clean_list; /* unused & unamapped MRs */
atomic_t free_pinned; /* memory pinned by free MRs */
unsigned long max_message_size; /* in pages */
unsigned long max_items;
unsigned long max_items_soft;
unsigned long max_free_pinned;
int max_pages;
};
static int rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all);
static void rds_iw_mr_pool_flush_worker(struct work_struct *work);
static int rds_iw_init_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
static int rds_iw_map_fastreg(struct rds_iw_mr_pool *pool,
struct rds_iw_mr *ibmr,
struct scatterlist *sg, unsigned int nents);
static void rds_iw_free_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
static unsigned int rds_iw_unmap_fastreg_list(struct rds_iw_mr_pool *pool,
struct list_head *unmap_list,
struct list_head *kill_list);
static void rds_iw_destroy_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
static int rds_iw_get_device(struct rds_sock *rs, struct rds_iw_device **rds_iwdev, struct rdma_cm_id **cm_id)
{
struct rds_iw_device *iwdev;
struct rds_iw_cm_id *i_cm_id;
*rds_iwdev = NULL;
*cm_id = NULL;
list_for_each_entry(iwdev, &rds_iw_devices, list) {
spin_lock_irq(&iwdev->spinlock);
list_for_each_entry(i_cm_id, &iwdev->cm_id_list, list) {
struct sockaddr_in *src_addr, *dst_addr;
src_addr = (struct sockaddr_in *)&i_cm_id->cm_id->route.addr.src_addr;
dst_addr = (struct sockaddr_in *)&i_cm_id->cm_id->route.addr.dst_addr;
rdsdebug("local ipaddr = %x port %d, "
"remote ipaddr = %x port %d"
"..looking for %x port %d, "
"remote ipaddr = %x port %d\n",
src_addr->sin_addr.s_addr,
src_addr->sin_port,
dst_addr->sin_addr.s_addr,
dst_addr->sin_port,
rs->rs_bound_addr,
rs->rs_bound_port,
rs->rs_conn_addr,
rs->rs_conn_port);
#ifdef WORKING_TUPLE_DETECTION
if (src_addr->sin_addr.s_addr == rs->rs_bound_addr &&
src_addr->sin_port == rs->rs_bound_port &&
dst_addr->sin_addr.s_addr == rs->rs_conn_addr &&
dst_addr->sin_port == rs->rs_conn_port) {
#else
/* FIXME - needs to compare the local and remote
* ipaddr/port tuple, but the ipaddr is the only
* available information in the rds_sock (as the rest are
* zero'ed. It doesn't appear to be properly populated
* during connection setup...
*/
if (src_addr->sin_addr.s_addr == rs->rs_bound_addr) {
#endif
spin_unlock_irq(&iwdev->spinlock);
*rds_iwdev = iwdev;
*cm_id = i_cm_id->cm_id;
return 0;
}
}
spin_unlock_irq(&iwdev->spinlock);
}
return 1;
}
static int rds_iw_add_cm_id(struct rds_iw_device *rds_iwdev, struct rdma_cm_id *cm_id)
{
struct rds_iw_cm_id *i_cm_id;
i_cm_id = kmalloc(sizeof *i_cm_id, GFP_KERNEL);
if (!i_cm_id)
return -ENOMEM;
i_cm_id->cm_id = cm_id;
spin_lock_irq(&rds_iwdev->spinlock);
list_add_tail(&i_cm_id->list, &rds_iwdev->cm_id_list);
spin_unlock_irq(&rds_iwdev->spinlock);
return 0;
}
static void rds_iw_remove_cm_id(struct rds_iw_device *rds_iwdev,
struct rdma_cm_id *cm_id)
{
struct rds_iw_cm_id *i_cm_id;
spin_lock_irq(&rds_iwdev->spinlock);
list_for_each_entry(i_cm_id, &rds_iwdev->cm_id_list, list) {
if (i_cm_id->cm_id == cm_id) {
list_del(&i_cm_id->list);
kfree(i_cm_id);
break;
}
}
spin_unlock_irq(&rds_iwdev->spinlock);
}
int rds_iw_update_cm_id(struct rds_iw_device *rds_iwdev, struct rdma_cm_id *cm_id)
{
struct sockaddr_in *src_addr, *dst_addr;
struct rds_iw_device *rds_iwdev_old;
struct rds_sock rs;
struct rdma_cm_id *pcm_id;
int rc;
src_addr = (struct sockaddr_in *)&cm_id->route.addr.src_addr;
dst_addr = (struct sockaddr_in *)&cm_id->route.addr.dst_addr;
rs.rs_bound_addr = src_addr->sin_addr.s_addr;
rs.rs_bound_port = src_addr->sin_port;
rs.rs_conn_addr = dst_addr->sin_addr.s_addr;
rs.rs_conn_port = dst_addr->sin_port;
rc = rds_iw_get_device(&rs, &rds_iwdev_old, &pcm_id);
if (rc)
rds_iw_remove_cm_id(rds_iwdev, cm_id);
return rds_iw_add_cm_id(rds_iwdev, cm_id);
}
void rds_iw_add_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn)
{
struct rds_iw_connection *ic = conn->c_transport_data;
/* conn was previously on the nodev_conns_list */
spin_lock_irq(&iw_nodev_conns_lock);
BUG_ON(list_empty(&iw_nodev_conns));
BUG_ON(list_empty(&ic->iw_node));
list_del(&ic->iw_node);
spin_lock(&rds_iwdev->spinlock);
list_add_tail(&ic->iw_node, &rds_iwdev->conn_list);
spin_unlock(&rds_iwdev->spinlock);
spin_unlock_irq(&iw_nodev_conns_lock);
ic->rds_iwdev = rds_iwdev;
}
void rds_iw_remove_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn)
{
struct rds_iw_connection *ic = conn->c_transport_data;
/* place conn on nodev_conns_list */
spin_lock(&iw_nodev_conns_lock);
spin_lock_irq(&rds_iwdev->spinlock);
BUG_ON(list_empty(&ic->iw_node));
list_del(&ic->iw_node);
spin_unlock_irq(&rds_iwdev->spinlock);
list_add_tail(&ic->iw_node, &iw_nodev_conns);
spin_unlock(&iw_nodev_conns_lock);
rds_iw_remove_cm_id(ic->rds_iwdev, ic->i_cm_id);
ic->rds_iwdev = NULL;
}
void __rds_iw_destroy_conns(struct list_head *list, spinlock_t *list_lock)
{
struct rds_iw_connection *ic, *_ic;
LIST_HEAD(tmp_list);
/* avoid calling conn_destroy with irqs off */
spin_lock_irq(list_lock);
list_splice(list, &tmp_list);
INIT_LIST_HEAD(list);
spin_unlock_irq(list_lock);
list_for_each_entry_safe(ic, _ic, &tmp_list, iw_node)
rds_conn_destroy(ic->conn);
}
static void rds_iw_set_scatterlist(struct rds_iw_scatterlist *sg,
struct scatterlist *list, unsigned int sg_len)
{
sg->list = list;
sg->len = sg_len;
sg->dma_len = 0;
sg->dma_npages = 0;
sg->bytes = 0;
}
static u64 *rds_iw_map_scatterlist(struct rds_iw_device *rds_iwdev,
struct rds_iw_scatterlist *sg)
{
struct ib_device *dev = rds_iwdev->dev;
u64 *dma_pages = NULL;
int i, j, ret;
WARN_ON(sg->dma_len);
sg->dma_len = ib_dma_map_sg(dev, sg->list, sg->len, DMA_BIDIRECTIONAL);
if (unlikely(!sg->dma_len)) {
printk(KERN_WARNING "RDS/IW: dma_map_sg failed!\n");
return ERR_PTR(-EBUSY);
}
sg->bytes = 0;
sg->dma_npages = 0;
ret = -EINVAL;
for (i = 0; i < sg->dma_len; ++i) {
unsigned int dma_len = ib_sg_dma_len(dev, &sg->list[i]);
u64 dma_addr = ib_sg_dma_address(dev, &sg->list[i]);
u64 end_addr;
sg->bytes += dma_len;
end_addr = dma_addr + dma_len;
if (dma_addr & PAGE_MASK) {
if (i > 0)
goto out_unmap;
dma_addr &= ~PAGE_MASK;
}
if (end_addr & PAGE_MASK) {
if (i < sg->dma_len - 1)
goto out_unmap;
end_addr = (end_addr + PAGE_MASK) & ~PAGE_MASK;
}
sg->dma_npages += (end_addr - dma_addr) >> PAGE_SHIFT;
}
/* Now gather the dma addrs into one list */
if (sg->dma_npages > fastreg_message_size)
goto out_unmap;
dma_pages = kmalloc(sizeof(u64) * sg->dma_npages, GFP_ATOMIC);
if (!dma_pages) {
ret = -ENOMEM;
goto out_unmap;
}
for (i = j = 0; i < sg->dma_len; ++i) {
unsigned int dma_len = ib_sg_dma_len(dev, &sg->list[i]);
u64 dma_addr = ib_sg_dma_address(dev, &sg->list[i]);
u64 end_addr;
end_addr = dma_addr + dma_len;
dma_addr &= ~PAGE_MASK;
for (; dma_addr < end_addr; dma_addr += PAGE_SIZE)
dma_pages[j++] = dma_addr;
BUG_ON(j > sg->dma_npages);
}
return dma_pages;
out_unmap:
ib_dma_unmap_sg(rds_iwdev->dev, sg->list, sg->len, DMA_BIDIRECTIONAL);
sg->dma_len = 0;
kfree(dma_pages);
return ERR_PTR(ret);
}
struct rds_iw_mr_pool *rds_iw_create_mr_pool(struct rds_iw_device *rds_iwdev)
{
struct rds_iw_mr_pool *pool;
pool = kzalloc(sizeof(*pool), GFP_KERNEL);
if (!pool) {
printk(KERN_WARNING "RDS/IW: rds_iw_create_mr_pool alloc error\n");
return ERR_PTR(-ENOMEM);
}
pool->device = rds_iwdev;
INIT_LIST_HEAD(&pool->dirty_list);
INIT_LIST_HEAD(&pool->clean_list);
mutex_init(&pool->flush_lock);
spin_lock_init(&pool->list_lock);
INIT_WORK(&pool->flush_worker, rds_iw_mr_pool_flush_worker);
pool->max_message_size = fastreg_message_size;
pool->max_items = fastreg_pool_size;
pool->max_free_pinned = pool->max_items * pool->max_message_size / 4;
pool->max_pages = fastreg_message_size;
/* We never allow more than max_items MRs to be allocated.
* When we exceed more than max_items_soft, we start freeing
* items more aggressively.
* Make sure that max_items > max_items_soft > max_items / 2
*/
pool->max_items_soft = pool->max_items * 3 / 4;
return pool;
}
void rds_iw_get_mr_info(struct rds_iw_device *rds_iwdev, struct rds_info_rdma_connection *iinfo)
{
struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
iinfo->rdma_mr_max = pool->max_items;
iinfo->rdma_mr_size = pool->max_pages;
}
void rds_iw_destroy_mr_pool(struct rds_iw_mr_pool *pool)
{
flush_workqueue(rds_wq);
rds_iw_flush_mr_pool(pool, 1);
BUG_ON(atomic_read(&pool->item_count));
BUG_ON(atomic_read(&pool->free_pinned));
kfree(pool);
}
static inline struct rds_iw_mr *rds_iw_reuse_fmr(struct rds_iw_mr_pool *pool)
{
struct rds_iw_mr *ibmr = NULL;
unsigned long flags;
spin_lock_irqsave(&pool->list_lock, flags);
if (!list_empty(&pool->clean_list)) {
ibmr = list_entry(pool->clean_list.next, struct rds_iw_mr, mapping.m_list);
list_del_init(&ibmr->mapping.m_list);
}
spin_unlock_irqrestore(&pool->list_lock, flags);
return ibmr;
}
static struct rds_iw_mr *rds_iw_alloc_mr(struct rds_iw_device *rds_iwdev)
{
struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
struct rds_iw_mr *ibmr = NULL;
int err = 0, iter = 0;
while (1) {
ibmr = rds_iw_reuse_fmr(pool);
if (ibmr)
return ibmr;
/* No clean MRs - now we have the choice of either
* allocating a fresh MR up to the limit imposed by the
* driver, or flush any dirty unused MRs.
* We try to avoid stalling in the send path if possible,
* so we allocate as long as we're allowed to.
*
* We're fussy with enforcing the FMR limit, though. If the driver
* tells us we can't use more than N fmrs, we shouldn't start
* arguing with it */
if (atomic_inc_return(&pool->item_count) <= pool->max_items)
break;
atomic_dec(&pool->item_count);
if (++iter > 2) {
rds_iw_stats_inc(s_iw_rdma_mr_pool_depleted);
return ERR_PTR(-EAGAIN);
}
/* We do have some empty MRs. Flush them out. */
rds_iw_stats_inc(s_iw_rdma_mr_pool_wait);
rds_iw_flush_mr_pool(pool, 0);
}
ibmr = kzalloc(sizeof(*ibmr), GFP_KERNEL);
if (!ibmr) {
err = -ENOMEM;
goto out_no_cigar;
}
spin_lock_init(&ibmr->mapping.m_lock);
INIT_LIST_HEAD(&ibmr->mapping.m_list);
ibmr->mapping.m_mr = ibmr;
err = rds_iw_init_fastreg(pool, ibmr);
if (err)
goto out_no_cigar;
rds_iw_stats_inc(s_iw_rdma_mr_alloc);
return ibmr;
out_no_cigar:
if (ibmr) {
rds_iw_destroy_fastreg(pool, ibmr);
kfree(ibmr);
}
atomic_dec(&pool->item_count);
return ERR_PTR(err);
}
void rds_iw_sync_mr(void *trans_private, int direction)
{
struct rds_iw_mr *ibmr = trans_private;
struct rds_iw_device *rds_iwdev = ibmr->device;
switch (direction) {
case DMA_FROM_DEVICE:
ib_dma_sync_sg_for_cpu(rds_iwdev->dev, ibmr->mapping.m_sg.list,
ibmr->mapping.m_sg.dma_len, DMA_BIDIRECTIONAL);
break;
case DMA_TO_DEVICE:
ib_dma_sync_sg_for_device(rds_iwdev->dev, ibmr->mapping.m_sg.list,
ibmr->mapping.m_sg.dma_len, DMA_BIDIRECTIONAL);
break;
}
}
static inline unsigned int rds_iw_flush_goal(struct rds_iw_mr_pool *pool, int free_all)
{
unsigned int item_count;
item_count = atomic_read(&pool->item_count);
if (free_all)
return item_count;
return 0;
}
/*
* Flush our pool of MRs.
* At a minimum, all currently unused MRs are unmapped.
* If the number of MRs allocated exceeds the limit, we also try
* to free as many MRs as needed to get back to this limit.
*/
static int rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all)
{
struct rds_iw_mr *ibmr, *next;
LIST_HEAD(unmap_list);
LIST_HEAD(kill_list);
unsigned long flags;
unsigned int nfreed = 0, ncleaned = 0, free_goal;
int ret = 0;
rds_iw_stats_inc(s_iw_rdma_mr_pool_flush);
mutex_lock(&pool->flush_lock);
spin_lock_irqsave(&pool->list_lock, flags);
/* Get the list of all mappings to be destroyed */
list_splice_init(&pool->dirty_list, &unmap_list);
if (free_all)
list_splice_init(&pool->clean_list, &kill_list);
spin_unlock_irqrestore(&pool->list_lock, flags);
free_goal = rds_iw_flush_goal(pool, free_all);
/* Batched invalidate of dirty MRs.
* For FMR based MRs, the mappings on the unmap list are
* actually members of an ibmr (ibmr->mapping). They either
* migrate to the kill_list, or have been cleaned and should be
* moved to the clean_list.
* For fastregs, they will be dynamically allocated, and
* will be destroyed by the unmap function.
*/
if (!list_empty(&unmap_list)) {
ncleaned = rds_iw_unmap_fastreg_list(pool, &unmap_list, &kill_list);
/* If we've been asked to destroy all MRs, move those
* that were simply cleaned to the kill list */
if (free_all)
list_splice_init(&unmap_list, &kill_list);
}
/* Destroy any MRs that are past their best before date */
list_for_each_entry_safe(ibmr, next, &kill_list, mapping.m_list) {
rds_iw_stats_inc(s_iw_rdma_mr_free);
list_del(&ibmr->mapping.m_list);
rds_iw_destroy_fastreg(pool, ibmr);
kfree(ibmr);
nfreed++;
}
/* Anything that remains are laundered ibmrs, which we can add
* back to the clean list. */
if (!list_empty(&unmap_list)) {
spin_lock_irqsave(&pool->list_lock, flags);
list_splice(&unmap_list, &pool->clean_list);
spin_unlock_irqrestore(&pool->list_lock, flags);
}
atomic_sub(ncleaned, &pool->dirty_count);
atomic_sub(nfreed, &pool->item_count);
mutex_unlock(&pool->flush_lock);
return ret;
}
static void rds_iw_mr_pool_flush_worker(struct work_struct *work)
{
struct rds_iw_mr_pool *pool = container_of(work, struct rds_iw_mr_pool, flush_worker);
rds_iw_flush_mr_pool(pool, 0);
}
void rds_iw_free_mr(void *trans_private, int invalidate)
{
struct rds_iw_mr *ibmr = trans_private;
struct rds_iw_mr_pool *pool = ibmr->device->mr_pool;
rdsdebug("RDS/IW: free_mr nents %u\n", ibmr->mapping.m_sg.len);
if (!pool)
return;
/* Return it to the pool's free list */
rds_iw_free_fastreg(pool, ibmr);
/* 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 / 10)
queue_work(rds_wq, &pool->flush_worker);
if (invalidate) {
if (likely(!in_interrupt())) {
rds_iw_flush_mr_pool(pool, 0);
} else {
/* We get here if the user created a MR marked
* as use_once and invalidate at the same time. */
queue_work(rds_wq, &pool->flush_worker);
}
}
}
void rds_iw_flush_mrs(void)
{
struct rds_iw_device *rds_iwdev;
list_for_each_entry(rds_iwdev, &rds_iw_devices, list) {
struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
if (pool)
rds_iw_flush_mr_pool(pool, 0);
}
}
void *rds_iw_get_mr(struct scatterlist *sg, unsigned long nents,
struct rds_sock *rs, u32 *key_ret)
{
struct rds_iw_device *rds_iwdev;
struct rds_iw_mr *ibmr = NULL;
struct rdma_cm_id *cm_id;
int ret;
ret = rds_iw_get_device(rs, &rds_iwdev, &cm_id);
if (ret || !cm_id) {
ret = -ENODEV;
goto out;
}
if (!rds_iwdev->mr_pool) {
ret = -ENODEV;
goto out;
}
ibmr = rds_iw_alloc_mr(rds_iwdev);
if (IS_ERR(ibmr))
return ibmr;
ibmr->cm_id = cm_id;
ibmr->device = rds_iwdev;
ret = rds_iw_map_fastreg(rds_iwdev->mr_pool, ibmr, sg, nents);
if (ret == 0)
*key_ret = ibmr->mr->rkey;
else
printk(KERN_WARNING "RDS/IW: failed to map mr (errno=%d)\n", ret);
out:
if (ret) {
if (ibmr)
rds_iw_free_mr(ibmr, 0);
ibmr = ERR_PTR(ret);
}
return ibmr;
}
/*
* iWARP fastreg handling
*
* The life cycle of a fastreg registration is a bit different from
* FMRs.
* The idea behind fastreg is to have one MR, to which we bind different
* mappings over time. To avoid stalling on the expensive map and invalidate
* operations, these operations are pipelined on the same send queue on
* which we want to send the message containing the r_key.
*
* This creates a bit of a problem for us, as we do not have the destination
* IP in GET_MR, so the connection must be setup prior to the GET_MR call for
* RDMA to be correctly setup. If a fastreg request is present, rds_iw_xmit
* will try to queue a LOCAL_INV (if needed) and a FAST_REG_MR work request
* before queuing the SEND. When completions for these arrive, they are
* dispatched to the MR has a bit set showing that RDMa can be performed.
*
* There is another interesting aspect that's related to invalidation.
* The application can request that a mapping is invalidated in FREE_MR.
* The expectation there is that this invalidation step includes ALL
* PREVIOUSLY FREED MRs.
*/
static int rds_iw_init_fastreg(struct rds_iw_mr_pool *pool,
struct rds_iw_mr *ibmr)
{
struct rds_iw_device *rds_iwdev = pool->device;
struct ib_fast_reg_page_list *page_list = NULL;
struct ib_mr *mr;
int err;
mr = ib_alloc_fast_reg_mr(rds_iwdev->pd, pool->max_message_size);
if (IS_ERR(mr)) {
err = PTR_ERR(mr);
printk(KERN_WARNING "RDS/IW: ib_alloc_fast_reg_mr failed (err=%d)\n", err);
return err;
}
/* FIXME - this is overkill, but mapping->m_sg.dma_len/mapping->m_sg.dma_npages
* is not filled in.
*/
page_list = ib_alloc_fast_reg_page_list(rds_iwdev->dev, pool->max_message_size);
if (IS_ERR(page_list)) {
err = PTR_ERR(page_list);
printk(KERN_WARNING "RDS/IW: ib_alloc_fast_reg_page_list failed (err=%d)\n", err);
ib_dereg_mr(mr);
return err;
}
ibmr->page_list = page_list;
ibmr->mr = mr;
return 0;
}
static int rds_iw_rdma_build_fastreg(struct rds_iw_mapping *mapping)
{
struct rds_iw_mr *ibmr = mapping->m_mr;
struct ib_send_wr f_wr, *failed_wr;
int ret;
/*
* 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(ibmr->mr, ibmr->remap_count++);
mapping->m_rkey = ibmr->mr->rkey;
memset(&f_wr, 0, sizeof(f_wr));
f_wr.wr_id = RDS_IW_FAST_REG_WR_ID;
f_wr.opcode = IB_WR_FAST_REG_MR;
f_wr.wr.fast_reg.length = mapping->m_sg.bytes;
f_wr.wr.fast_reg.rkey = mapping->m_rkey;
f_wr.wr.fast_reg.page_list = ibmr->page_list;
f_wr.wr.fast_reg.page_list_len = mapping->m_sg.dma_len;
f_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
f_wr.wr.fast_reg.access_flags = IB_ACCESS_LOCAL_WRITE |
IB_ACCESS_REMOTE_READ |
IB_ACCESS_REMOTE_WRITE;
f_wr.wr.fast_reg.iova_start = 0;
f_wr.send_flags = IB_SEND_SIGNALED;
failed_wr = &f_wr;
ret = ib_post_send(ibmr->cm_id->qp, &f_wr, &failed_wr);
BUG_ON(failed_wr != &f_wr);
if (ret)
printk_ratelimited(KERN_WARNING "RDS/IW: %s:%d ib_post_send returned %d\n",
__func__, __LINE__, ret);
return ret;
}
static int rds_iw_rdma_fastreg_inv(struct rds_iw_mr *ibmr)
{
struct ib_send_wr s_wr, *failed_wr;
int ret = 0;
if (!ibmr->cm_id->qp || !ibmr->mr)
goto out;
memset(&s_wr, 0, sizeof(s_wr));
s_wr.wr_id = RDS_IW_LOCAL_INV_WR_ID;
s_wr.opcode = IB_WR_LOCAL_INV;
s_wr.ex.invalidate_rkey = ibmr->mr->rkey;
s_wr.send_flags = IB_SEND_SIGNALED;
failed_wr = &s_wr;
ret = ib_post_send(ibmr->cm_id->qp, &s_wr, &failed_wr);
if (ret) {
printk_ratelimited(KERN_WARNING "RDS/IW: %s:%d ib_post_send returned %d\n",
__func__, __LINE__, ret);
goto out;
}
out:
return ret;
}
static int rds_iw_map_fastreg(struct rds_iw_mr_pool *pool,
struct rds_iw_mr *ibmr,
struct scatterlist *sg,
unsigned int sg_len)
{
struct rds_iw_device *rds_iwdev = pool->device;
struct rds_iw_mapping *mapping = &ibmr->mapping;
u64 *dma_pages;
int i, ret = 0;
rds_iw_set_scatterlist(&mapping->m_sg, sg, sg_len);
dma_pages = rds_iw_map_scatterlist(rds_iwdev, &mapping->m_sg);
if (IS_ERR(dma_pages)) {
ret = PTR_ERR(dma_pages);
dma_pages = NULL;
goto out;
}
if (mapping->m_sg.dma_len > pool->max_message_size) {
ret = -EMSGSIZE;
goto out;
}
for (i = 0; i < mapping->m_sg.dma_npages; ++i)
ibmr->page_list->page_list[i] = dma_pages[i];
ret = rds_iw_rdma_build_fastreg(mapping);
if (ret)
goto out;
rds_iw_stats_inc(s_iw_rdma_mr_used);
out:
kfree(dma_pages);
return ret;
}
/*
* "Free" a fastreg MR.
*/
static void rds_iw_free_fastreg(struct rds_iw_mr_pool *pool,
struct rds_iw_mr *ibmr)
{
unsigned long flags;
int ret;
if (!ibmr->mapping.m_sg.dma_len)
return;
ret = rds_iw_rdma_fastreg_inv(ibmr);
if (ret)
return;
/* Try to post the LOCAL_INV WR to the queue. */
spin_lock_irqsave(&pool->list_lock, flags);
list_add_tail(&ibmr->mapping.m_list, &pool->dirty_list);
atomic_add(ibmr->mapping.m_sg.len, &pool->free_pinned);
atomic_inc(&pool->dirty_count);
spin_unlock_irqrestore(&pool->list_lock, flags);
}
static unsigned int rds_iw_unmap_fastreg_list(struct rds_iw_mr_pool *pool,
struct list_head *unmap_list,
struct list_head *kill_list)
{
struct rds_iw_mapping *mapping, *next;
unsigned int ncleaned = 0;
LIST_HEAD(laundered);
/* Batched invalidation of fastreg MRs.
* Why do we do it this way, even though we could pipeline unmap
* and remap? The reason is the application semantics - when the
* application requests an invalidation of MRs, it expects all
* previously released R_Keys to become invalid.
*
* If we implement MR reuse naively, we risk memory corruption
* (this has actually been observed). So the default behavior
* requires that a MR goes through an explicit unmap operation before
* we can reuse it again.
*
* We could probably improve on this a little, by allowing immediate
* reuse of a MR on the same socket (eg you could add small
* cache of unused MRs to strct rds_socket - GET_MR could grab one
* of these without requiring an explicit invalidate).
*/
while (!list_empty(unmap_list)) {
unsigned long flags;
spin_lock_irqsave(&pool->list_lock, flags);
list_for_each_entry_safe(mapping, next, unmap_list, m_list) {
list_move(&mapping->m_list, &laundered);
ncleaned++;
}
spin_unlock_irqrestore(&pool->list_lock, flags);
}
/* Move all laundered mappings back to the unmap list.
* We do not kill any WRs right now - it doesn't seem the
* fastreg API has a max_remap limit. */
list_splice_init(&laundered, unmap_list);
return ncleaned;
}
static void rds_iw_destroy_fastreg(struct rds_iw_mr_pool *pool,
struct rds_iw_mr *ibmr)
{
if (ibmr->page_list)
ib_free_fast_reg_page_list(ibmr->page_list);
if (ibmr->mr)
ib_dereg_mr(ibmr->mr);
}
