/*
* 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 "rds.h"
#include "rdma.h"
#include "ib.h"
/*
* This is stored as mr->r_trans_private.
*/
struct rds_ib_mr {
struct rds_ib_device *device;
struct rds_ib_mr_pool *pool;
struct ib_fmr *fmr;
struct list_head list;
unsigned int remap_count;
struct scatterlist *sg;
unsigned int sg_len;
u64 *dma;
int sg_dma_len;
};
/*
* Our own little FMR pool
*/
struct rds_ib_mr_pool {
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 drop_list; /* MRs that have reached their max_maps limit */
struct list_head free_list; /* unused MRs */
struct list_head clean_list; /* unused & unamapped MRs */
atomic_t free_pinned; /* memory pinned by free MRs */
unsigned long max_items;
unsigned long max_items_soft;
unsigned long max_free_pinned;
struct ib_fmr_attr fmr_attr;
};
static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all);
static void rds_ib_teardown_mr(struct rds_ib_mr *ibmr);
static void rds_ib_mr_pool_flush_worker(struct work_struct *work);
static struct rds_ib_device *rds_ib_get_device(__be32 ipaddr)
{
struct rds_ib_device *rds_ibdev;
struct rds_ib_ipaddr *i_ipaddr;
list_for_each_entry(rds_ibdev, &rds_ib_devices, list) {
spin_lock_irq(&rds_ibdev->spinlock);
list_for_each_entry(i_ipaddr, &rds_ibdev->ipaddr_list, list) {
if (i_ipaddr->ipaddr == ipaddr) {
spin_unlock_irq(&rds_ibdev->spinlock);
return rds_ibdev;
}
}
spin_unlock_irq(&rds_ibdev->spinlock);
}
return NULL;
}
static int rds_ib_add_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
{
struct rds_ib_ipaddr *i_ipaddr;
i_ipaddr = kmalloc(sizeof *i_ipaddr, GFP_KERNEL);
if (!i_ipaddr)
return -ENOMEM;
i_ipaddr->ipaddr = ipaddr;
spin_lock_irq(&rds_ibdev->spinlock);
list_add_tail(&i_ipaddr->list, &rds_ibdev->ipaddr_list);
spin_unlock_irq(&rds_ibdev->spinlock);
return 0;
}
static void rds_ib_remove_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
{
struct rds_ib_ipaddr *i_ipaddr, *next;
spin_lock_irq(&rds_ibdev->spinlock);
list_for_each_entry_safe(i_ipaddr, next, &rds_ibdev->ipaddr_list, list) {
if (i_ipaddr->ipaddr == ipaddr) {
list_del(&i_ipaddr->list);
kfree(i_ipaddr);
break;
}
}
spin_unlock_irq(&rds_ibdev->spinlock);
}
int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
{
struct rds_ib_device *rds_ibdev_old;
rds_ibdev_old = rds_ib_get_device(ipaddr);
if (rds_ibdev_old)
rds_ib_remove_ipaddr(rds_ibdev_old, ipaddr);
return rds_ib_add_ipaddr(rds_ibdev, ipaddr);
}
void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
{
struct rds_ib_connection *ic = conn->c_transport_data;
/* conn was previously on the nodev_conns_list */
spin_lock_irq(&ib_nodev_conns_lock);
BUG_ON(list_empty(&ib_nodev_conns));
BUG_ON(list_empty(&ic->ib_node));
list_del(&ic->ib_node);
spin_lock_irq(&rds_ibdev->spinlock);
list_add_tail(&ic->ib_node, &rds_ibdev->conn_list);
spin_unlock_irq(&rds_ibdev->spinlock);
spin_unlock_irq(&ib_nodev_conns_lock);
ic->rds_ibdev = rds_ibdev;
}
void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
{
struct rds_ib_connection *ic = conn->c_transport_data;
/* place conn on nodev_conns_list */
spin_lock(&ib_nodev_conns_lock);
spin_lock_irq(&rds_ibdev->spinlock);
BUG_ON(list_empty(&ic->ib_node));
list_del(&ic->ib_node);
spin_unlock_irq(&rds_ibdev->spinlock);
list_add_tail(&ic->ib_node, &ib_nodev_conns);
spin_unlock(&ib_nodev_conns_lock);
ic->rds_ibdev = NULL;
}
void __rds_ib_destroy_conns(struct list_head *list, spinlock_t *list_lock)
{
struct rds_ib_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, ib_node) {
if (ic->conn->c_passive)
rds_conn_destroy(ic->conn->c_passive);
rds_conn_destroy(ic->conn);
}
}
struct rds_ib_mr_pool *rds_ib_create_mr_pool(struct rds_ib_device *rds_ibdev)
{
struct rds_ib_mr_pool *pool;
pool = kzalloc(sizeof(*pool), GFP_KERNEL);
if (!pool)
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&pool->free_list);
INIT_LIST_HEAD(&pool->drop_list);
INIT_LIST_HEAD(&pool->clean_list);
mutex_init(&pool->flush_lock);
spin_lock_init(&pool->list_lock);
INIT_WORK(&pool->flush_worker, rds_ib_mr_pool_flush_worker);
pool->fmr_attr.max_pages = fmr_message_size;
pool->fmr_attr.max_maps = rds_ibdev->fmr_max_remaps;
pool->fmr_attr.page_shift = PAGE_SHIFT;
pool->max_free_pinned = rds_ibdev->max_fmrs * fmr_message_size / 4;
/* 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 = rds_ibdev->max_fmrs * 3 / 4;
pool->max_items = rds_ibdev->max_fmrs;
return pool;
}
void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_connection *iinfo)
{
struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
iinfo->rdma_mr_max = pool->max_items;
iinfo->rdma_mr_size = pool->fmr_attr.max_pages;
}
void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *pool)
{
flush_workqueue(rds_wq);
rds_ib_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_ib_mr *rds_ib_reuse_fmr(struct rds_ib_mr_pool *pool)
{
struct rds_ib_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_ib_mr, list);
list_del_init(&ibmr->list);
}
spin_unlock_irqrestore(&pool->list_lock, flags);
return ibmr;
}
static struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *rds_ibdev)
{
struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
struct rds_ib_mr *ibmr = NULL;
int err = 0, iter = 0;
while (1) {
ibmr = rds_ib_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_ib_stats_inc(s_ib_rdma_mr_pool_depleted);
return ERR_PTR(-EAGAIN);
}
/* We do have some empty MRs. Flush them out. */
rds_ib_stats_inc(s_ib_rdma_mr_pool_wait);
rds_ib_flush_mr_pool(pool, 0);
}
ibmr = kzalloc(sizeof(*ibmr), GFP_KERNEL);
if (!ibmr) {
err = -ENOMEM;
goto out_no_cigar;
}
ibmr->fmr = ib_alloc_fmr(rds_ibdev->pd,
(IB_ACCESS_LOCAL_WRITE |
IB_ACCESS_REMOTE_READ |
IB_ACCESS_REMOTE_WRITE),
&pool->fmr_attr);
if (IS_ERR(ibmr->fmr)) {
err = PTR_ERR(ibmr->fmr);
ibmr->fmr = NULL;
printk(KERN_WARNING "RDS/IB: ib_alloc_fmr failed (err=%d)\n", err);
goto out_no_cigar;
}
rds_ib_stats_inc(s_ib_rdma_mr_alloc);
return ibmr;
out_no_cigar:
if (ibmr) {
if (ibmr->fmr)
ib_dealloc_fmr(ibmr->fmr);
kfree(ibmr);
}
atomic_dec(&pool->item_count);
return ERR_PTR(err);
}
static int rds_ib_map_fmr(struct rds_ib_device *rds_ibdev, struct rds_ib_mr *ibmr,
struct scatterlist *sg, unsigned int nents)
{
struct ib_device *dev = rds_ibdev->dev;
struct scatterlist *scat = sg;
u64 io_addr = 0;
u64 *dma_pages;
u32 len;
int page_cnt, sg_dma_len;
int i, j;
int ret;
sg_dma_len = ib_dma_map_sg(dev, sg, nents,
DMA_BIDIRECTIONAL);
if (unlikely(!sg_dma_len)) {
printk(KERN_WARNING "RDS/IB: dma_map_sg failed!\n");
return -EBUSY;
}
len = 0;
page_cnt = 0;
for (i = 0; i < sg_dma_len; ++i) {
unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
if (dma_addr & ~PAGE_MASK) {
if (i > 0)
return -EINVAL;
else
++page_cnt;
}
if ((dma_addr + dma_len) & ~PAGE_MASK) {
if (i < sg_dma_len - 1)
return -EINVAL;
else
++page_cnt;
}
len += dma_len;
}
page_cnt += len >> PAGE_SHIFT;
if (page_cnt > fmr_message_size)
return -EINVAL;
dma_pages = kmalloc(sizeof(u64) * page_cnt, GFP_ATOMIC);
if (!dma_pages)
return -ENOMEM;
page_cnt = 0;
for (i = 0; i < sg_dma_len; ++i) {
unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
for (j = 0; j < dma_len; j += PAGE_SIZE)
dma_pages[page_cnt++] =
(dma_addr & PAGE_MASK) + j;
}
ret = ib_map_phys_fmr(ibmr->fmr,
dma_pages, page_cnt, io_addr);
if (ret)
goto out;
/* Success - we successfully remapped the MR, so we can
* safely tear down the old mapping. */
rds_ib_teardown_mr(ibmr);
ibmr->sg = scat;
ibmr->sg_len = nents;
ibmr->sg_dma_len = sg_dma_len;
ibmr->remap_count++;
rds_ib_stats_inc(s_ib_rdma_mr_used);
ret = 0;
out:
kfree(dma_pages);
return ret;
}
void rds_ib_sync_mr(void *trans_private, int direction)
{
struct rds_ib_mr *ibmr = trans_private;
struct rds_ib_device *rds_ibdev = ibmr->device;
switch (direction) {
case DMA_FROM_DEVICE:
ib_dma_sync_sg_for_cpu(rds_ibdev->dev, ibmr->sg,
ibmr->sg_dma_len, DMA_BIDIRECTIONAL);
break;
case DMA_TO_DEVICE:
ib_dma_sync_sg_for_device(rds_ibdev->dev, ibmr->sg,
ibmr->sg_dma_len, DMA_BIDIRECTIONAL);
break;
}
}
static void __rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
{
struct rds_ib_device *rds_ibdev = ibmr->device;
if (ibmr->sg_dma_len) {
ib_dma_unmap_sg(rds_ibdev->dev,
ibmr->sg, ibmr->sg_len,
DMA_BIDIRECTIONAL);
ibmr->sg_dma_len = 0;
}
/* Release the s/g list */
if (ibmr->sg_len) {
unsigned int i;
for (i = 0; i < ibmr->sg_len; ++i) {
struct page *page = sg_page(&ibmr->sg[i]);
/* FIXME we need a way to tell a r/w MR
* from a r/o MR */
set_page_dirty(page);
put_page(page);
}
kfree(ibmr->sg);
ibmr->sg = NULL;
ibmr->sg_len = 0;
}
}
static void rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
{
unsigned int pinned = ibmr->sg_len;
__rds_ib_teardown_mr(ibmr);
if (pinned) {
struct rds_ib_device *rds_ibdev = ibmr->device;
struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
atomic_sub(pinned, &pool->free_pinned);
}
}
static inline unsigned int rds_ib_flush_goal(struct rds_ib_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_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all)
{
struct rds_ib_mr *ibmr, *next;
LIST_HEAD(unmap_list);
LIST_HEAD(fmr_list);
unsigned long unpinned = 0;
unsigned long flags;
unsigned int nfreed = 0, ncleaned = 0, free_goal;
int ret = 0;
rds_ib_stats_inc(s_ib_rdma_mr_pool_flush);
mutex_lock(&pool->flush_lock);
spin_lock_irqsave(&pool->list_lock, flags);
/* Get the list of all MRs to be dropped. Ordering matters -
* we want to put drop_list ahead of free_list. */
list_splice_init(&pool->free_list, &unmap_list);
list_splice_init(&pool->drop_list, &unmap_list);
if (free_all)
list_splice_init(&pool->clean_list, &unmap_list);
spin_unlock_irqrestore(&pool->list_lock, flags);
free_goal = rds_ib_flush_goal(pool, free_all);
if (list_empty(&unmap_list))
goto out;
/* String all ib_mr's onto one list and hand them to ib_unmap_fmr */
list_for_each_entry(ibmr, &unmap_list, list)
list_add(&ibmr->fmr->list, &fmr_list);
ret = ib_unmap_fmr(&fmr_list);
if (ret)
printk(KERN_WARNING "RDS/IB: ib_unmap_fmr failed (err=%d)\n", ret);
/* Now we can destroy the DMA mapping and unpin any pages */
list_for_each_entry_safe(ibmr, next, &unmap_list, list) {
unpinned += ibmr->sg_len;
__rds_ib_teardown_mr(ibmr);
if (nfreed < free_goal || ibmr->remap_count >= pool->fmr_attr.max_maps) {
rds_ib_stats_inc(s_ib_rdma_mr_free);
list_del(&ibmr->list);
ib_dealloc_fmr(ibmr->fmr);
kfree(ibmr);
nfreed++;
}
ncleaned++;
}
spin_lock_irqsave(&pool->list_lock, flags);
list_splice(&unmap_list, &pool->clean_list);
spin_unlock_irqrestore(&pool->list_lock, flags);
atomic_sub(unpinned, &pool->free_pinned);
atomic_sub(ncleaned, &pool->dirty_count);
atomic_sub(nfreed, &pool->item_count);
out:
mutex_unlock(&pool->flush_lock);
return ret;
}
static void rds_ib_mr_pool_flush_worker(struct work_struct *work)
{
struct rds_ib_mr_pool *pool = container_of(work, struct rds_ib_mr_pool, flush_worker);
rds_ib_flush_mr_pool(pool, 0);
}
void rds_ib_free_mr(void *trans_private, int invalidate)
{
struct rds_ib_mr *ibmr = trans_private;
struct rds_ib_device *rds_ibdev = ibmr->device;
struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
unsigned long flags;
rdsdebug("RDS/IB: free_mr nents %u\n", ibmr->sg_len);
/* Return it to the pool's free list */
spin_lock_irqsave(&pool->list_lock, flags);
if (ibmr->remap_count >= pool->fmr_attr.max_maps)
list_add(&ibmr->list, &pool->drop_list);
else
list_add(&ibmr->list, &pool->free_list);
atomic_add(ibmr->sg_len, &pool->free_pinned);
atomic_inc(&pool->dirty_count);
spin_unlock_irqrestore(&pool->list_lock, flags);
/* 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_ib_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_ib_flush_mrs(void)
{
struct rds_ib_device *rds_ibdev;
list_for_each_entry(rds_ibdev, &rds_ib_devices, list) {
struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
if (pool)
rds_ib_flush_mr_pool(pool, 0);
}
}
void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
struct rds_sock *rs, u32 *key_ret)
{
struct rds_ib_device *rds_ibdev;
struct rds_ib_mr *ibmr = NULL;
int ret;
rds_ibdev = rds_ib_get_device(rs->rs_bound_addr);
if (!rds_ibdev) {
ret = -ENODEV;
goto out;
}
if (!rds_ibdev->mr_pool) {
ret = -ENODEV;
goto out;
}
ibmr = rds_ib_alloc_fmr(rds_ibdev);
if (IS_ERR(ibmr))
return ibmr;
ret = rds_ib_map_fmr(rds_ibdev, ibmr, sg, nents);
if (ret == 0)
*key_ret = ibmr->fmr->rkey;
else
printk(KERN_WARNING "RDS/IB: map_fmr failed (errno=%d)\n", ret);
ibmr->device = rds_ibdev;
out:
if (ret) {
if (ibmr)
rds_ib_free_mr(ibmr, 0);
ibmr = ERR_PTR(ret);
}
return ibmr;
}
