linux/net/rds/ib_rdma.c
Andy Grover a870d62726 RDS/IB: Always use PAGE_SIZE for FMR page size
While FMRs allow significant flexibility in what size of pages they can use,
we really just want FMR pages to match CPU page size. Roland says we can
count on this always being supported, so this simplifies things.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:13 -07:00

641 lines
16 KiB
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 "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;
}