/*
* Copyright (c) 2004 Topspin Communications. All rights reserved.
* Copyright (c) 2005 Sun Microsystems, Inc. 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.
*
* $Id: fmr_pool.c 2730 2005-06-28 16:43:03Z sean.hefty $
*/
#include <linux/errno.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/jhash.h>
#include <linux/kthread.h>
#include <rdma/ib_fmr_pool.h>
#include "core_priv.h"
enum {
IB_FMR_MAX_REMAPS = 32,
IB_FMR_HASH_BITS = 8,
IB_FMR_HASH_SIZE = 1 << IB_FMR_HASH_BITS,
IB_FMR_HASH_MASK = IB_FMR_HASH_SIZE - 1
};
/*
* If an FMR is not in use, then the list member will point to either
* its pool's free_list (if the FMR can be mapped again; that is,
* remap_count < IB_FMR_MAX_REMAPS) or its pool's dirty_list (if the
* FMR needs to be unmapped before being remapped). In either of
* these cases it is a bug if the ref_count is not 0. In other words,
* if ref_count is > 0, then the list member must not be linked into
* either free_list or dirty_list.
*
* The cache_node member is used to link the FMR into a cache bucket
* (if caching is enabled). This is independent of the reference
* count of the FMR. When a valid FMR is released, its ref_count is
* decremented, and if ref_count reaches 0, the FMR is placed in
* either free_list or dirty_list as appropriate. However, it is not
* removed from the cache and may be "revived" if a call to
* ib_fmr_register_physical() occurs before the FMR is remapped. In
* this case we just increment the ref_count and remove the FMR from
* free_list/dirty_list.
*
* Before we remap an FMR from free_list, we remove it from the cache
* (to prevent another user from obtaining a stale FMR). When an FMR
* is released, we add it to the tail of the free list, so that our
* cache eviction policy is "least recently used."
*
* All manipulation of ref_count, list and cache_node is protected by
* pool_lock to maintain consistency.
*/
struct ib_fmr_pool {
spinlock_t pool_lock;
int pool_size;
int max_pages;
int dirty_watermark;
int dirty_len;
struct list_head free_list;
struct list_head dirty_list;
struct hlist_head *cache_bucket;
void (*flush_function)(struct ib_fmr_pool *pool,
void * arg);
void *flush_arg;
struct task_struct *thread;
atomic_t req_ser;
atomic_t flush_ser;
wait_queue_head_t force_wait;
};
static inline u32 ib_fmr_hash(u64 first_page)
{
return jhash_2words((u32) first_page, (u32) (first_page >> 32), 0) &
(IB_FMR_HASH_SIZE - 1);
}
/* Caller must hold pool_lock */
static inline struct ib_pool_fmr *ib_fmr_cache_lookup(struct ib_fmr_pool *pool,
u64 *page_list,
int page_list_len,
u64 io_virtual_address)
{
struct hlist_head *bucket;
struct ib_pool_fmr *fmr;
struct hlist_node *pos;
if (!pool->cache_bucket)
return NULL;
bucket = pool->cache_bucket + ib_fmr_hash(*page_list);
hlist_for_each_entry(fmr, pos, bucket, cache_node)
if (io_virtual_address == fmr->io_virtual_address &&
page_list_len == fmr->page_list_len &&
!memcmp(page_list, fmr->page_list,
page_list_len * sizeof *page_list))
return fmr;
return NULL;
}
static void ib_fmr_batch_release(struct ib_fmr_pool *pool)
{
int ret;
struct ib_pool_fmr *fmr;
LIST_HEAD(unmap_list);
LIST_HEAD(fmr_list);
spin_lock_irq(&pool->pool_lock);
list_for_each_entry(fmr, &pool->dirty_list, list) {
hlist_del_init(&fmr->cache_node);
fmr->remap_count = 0;
list_add_tail(&fmr->fmr->list, &fmr_list);
#ifdef DEBUG
if (fmr->ref_count !=0) {
printk(KERN_WARNING "Unmapping FMR 0x%08x with ref count %d",
fmr, fmr->ref_count);
}
#endif
}
list_splice(&pool->dirty_list, &unmap_list);
INIT_LIST_HEAD(&pool->dirty_list);
pool->dirty_len = 0;
spin_unlock_irq(&pool->pool_lock);
if (list_empty(&unmap_list)) {
return;
}
ret = ib_unmap_fmr(&fmr_list);
if (ret)
printk(KERN_WARNING "ib_unmap_fmr returned %d", ret);
spin_lock_irq(&pool->pool_lock);
list_splice(&unmap_list, &pool->free_list);
spin_unlock_irq(&pool->pool_lock);
}
static int ib_fmr_cleanup_thread(void *pool_ptr)
{
struct ib_fmr_pool *pool = pool_ptr;
do {
if (pool->dirty_len >= pool->dirty_watermark ||
atomic_read(&pool->flush_ser) - atomic_read(&pool->req_ser) < 0) {
ib_fmr_batch_release(pool);
atomic_inc(&pool->flush_ser);
wake_up_interruptible(&pool->force_wait);
if (pool->flush_function)
pool->flush_function(pool, pool->flush_arg);
}
set_current_state(TASK_INTERRUPTIBLE);
if (pool->dirty_len < pool->dirty_watermark &&
atomic_read(&pool->flush_ser) - atomic_read(&pool->req_ser) >= 0 &&
!kthread_should_stop())
schedule();
__set_current_state(TASK_RUNNING);
} while (!kthread_should_stop());
return 0;
}
/**
* ib_create_fmr_pool - Create an FMR pool
* @pd:Protection domain for FMRs
* @params:FMR pool parameters
*
* Create a pool of FMRs. Return value is pointer to new pool or
* error code if creation failed.
*/
struct ib_fmr_pool *ib_create_fmr_pool(struct ib_pd *pd,
struct ib_fmr_pool_param *params)
{
struct ib_device *device;
struct ib_fmr_pool *pool;
int i;
int ret;
if (!params)
return ERR_PTR(-EINVAL);
device = pd->device;
if (!device->alloc_fmr || !device->dealloc_fmr ||
!device->map_phys_fmr || !device->unmap_fmr) {
printk(KERN_WARNING "Device %s does not support fast memory regions",
device->name);
return ERR_PTR(-ENOSYS);
}
pool = kmalloc(sizeof *pool, GFP_KERNEL);
if (!pool) {
printk(KERN_WARNING "couldn't allocate pool struct");
return ERR_PTR(-ENOMEM);
}
pool->cache_bucket = NULL;
pool->flush_function = params->flush_function;
pool->flush_arg = params->flush_arg;
INIT_LIST_HEAD(&pool->free_list);
INIT_LIST_HEAD(&pool->dirty_list);
if (params->cache) {
pool->cache_bucket =
kmalloc(IB_FMR_HASH_SIZE * sizeof *pool->cache_bucket,
GFP_KERNEL);
if (!pool->cache_bucket) {
printk(KERN_WARNING "Failed to allocate cache in pool");
ret = -ENOMEM;
goto out_free_pool;
}
for (i = 0; i < IB_FMR_HASH_SIZE; ++i)
INIT_HLIST_HEAD(pool->cache_bucket + i);
}
pool->pool_size = 0;
pool->max_pages = params->max_pages_per_fmr;
pool->dirty_watermark = params->dirty_watermark;
pool->dirty_len = 0;
spin_lock_init(&pool->pool_lock);
atomic_set(&pool->req_ser, 0);
atomic_set(&pool->flush_ser, 0);
init_waitqueue_head(&pool->force_wait);
pool->thread = kthread_create(ib_fmr_cleanup_thread,
pool,
"ib_fmr(%s)",
device->name);
if (IS_ERR(pool->thread)) {
printk(KERN_WARNING "couldn't start cleanup thread");
ret = PTR_ERR(pool->thread);
goto out_free_pool;
}
{
struct ib_pool_fmr *fmr;
struct ib_fmr_attr attr = {
.max_pages = params->max_pages_per_fmr,
.max_maps = IB_FMR_MAX_REMAPS,
.page_shift = params->page_shift
};
for (i = 0; i < params->pool_size; ++i) {
fmr = kmalloc(sizeof *fmr + params->max_pages_per_fmr * sizeof (u64),
GFP_KERNEL);
if (!fmr) {
printk(KERN_WARNING "failed to allocate fmr struct "
"for FMR %d", i);
goto out_fail;
}
fmr->pool = pool;
fmr->remap_count = 0;
fmr->ref_count = 0;
INIT_HLIST_NODE(&fmr->cache_node);
fmr->fmr = ib_alloc_fmr(pd, params->access, &attr);
if (IS_ERR(fmr->fmr)) {
printk(KERN_WARNING "fmr_create failed for FMR %d", i);
kfree(fmr);
goto out_fail;
}
list_add_tail(&fmr->list, &pool->free_list);
++pool->pool_size;
}
}
return pool;
out_free_pool:
kfree(pool->cache_bucket);
kfree(pool);
return ERR_PTR(ret);
out_fail:
ib_destroy_fmr_pool(pool);
return ERR_PTR(-ENOMEM);
}
EXPORT_SYMBOL(ib_create_fmr_pool);
/**
* ib_destroy_fmr_pool - Free FMR pool
* @pool:FMR pool to free
*
* Destroy an FMR pool and free all associated resources.
*/
void ib_destroy_fmr_pool(struct ib_fmr_pool *pool)
{
struct ib_pool_fmr *fmr;
struct ib_pool_fmr *tmp;
LIST_HEAD(fmr_list);
int i;
kthread_stop(pool->thread);
ib_fmr_batch_release(pool);
i = 0;
list_for_each_entry_safe(fmr, tmp, &pool->free_list, list) {
if (fmr->remap_count) {
INIT_LIST_HEAD(&fmr_list);
list_add_tail(&fmr->fmr->list, &fmr_list);
ib_unmap_fmr(&fmr_list);
}
ib_dealloc_fmr(fmr->fmr);
list_del(&fmr->list);
kfree(fmr);
++i;
}
if (i < pool->pool_size)
printk(KERN_WARNING "pool still has %d regions registered",
pool->pool_size - i);
kfree(pool->cache_bucket);
kfree(pool);
}
EXPORT_SYMBOL(ib_destroy_fmr_pool);
/**
* ib_flush_fmr_pool - Invalidate all unmapped FMRs
* @pool:FMR pool to flush
*
* Ensure that all unmapped FMRs are fully invalidated.
*/
int ib_flush_fmr_pool(struct ib_fmr_pool *pool)
{
int serial;
atomic_inc(&pool->req_ser);
/*
* It's OK if someone else bumps req_ser again here -- we'll
* just wait a little longer.
*/
serial = atomic_read(&pool->req_ser);
wake_up_process(pool->thread);
if (wait_event_interruptible(pool->force_wait,
atomic_read(&pool->flush_ser) -
atomic_read(&pool->req_ser) >= 0))
return -EINTR;
return 0;
}
EXPORT_SYMBOL(ib_flush_fmr_pool);
/**
* ib_fmr_pool_map_phys -
* @pool:FMR pool to allocate FMR from
* @page_list:List of pages to map
* @list_len:Number of pages in @page_list
* @io_virtual_address:I/O virtual address for new FMR
*
* Map an FMR from an FMR pool.
*/
struct ib_pool_fmr *ib_fmr_pool_map_phys(struct ib_fmr_pool *pool_handle,
u64 *page_list,
int list_len,
u64 *io_virtual_address)
{
struct ib_fmr_pool *pool = pool_handle;
struct ib_pool_fmr *fmr;
unsigned long flags;
int result;
if (list_len < 1 || list_len > pool->max_pages)
return ERR_PTR(-EINVAL);
spin_lock_irqsave(&pool->pool_lock, flags);
fmr = ib_fmr_cache_lookup(pool,
page_list,
list_len,
*io_virtual_address);
if (fmr) {
/* found in cache */
++fmr->ref_count;
if (fmr->ref_count == 1) {
list_del(&fmr->list);
}
spin_unlock_irqrestore(&pool->pool_lock, flags);
return fmr;
}
if (list_empty(&pool->free_list)) {
spin_unlock_irqrestore(&pool->pool_lock, flags);
return ERR_PTR(-EAGAIN);
}
fmr = list_entry(pool->free_list.next, struct ib_pool_fmr, list);
list_del(&fmr->list);
hlist_del_init(&fmr->cache_node);
spin_unlock_irqrestore(&pool->pool_lock, flags);
result = ib_map_phys_fmr(fmr->fmr, page_list, list_len,
*io_virtual_address);
if (result) {
spin_lock_irqsave(&pool->pool_lock, flags);
list_add(&fmr->list, &pool->free_list);
spin_unlock_irqrestore(&pool->pool_lock, flags);
printk(KERN_WARNING "fmr_map returns %d\n",
result);
return ERR_PTR(result);
}
++fmr->remap_count;
fmr->ref_count = 1;
if (pool->cache_bucket) {
fmr->io_virtual_address = *io_virtual_address;
fmr->page_list_len = list_len;
memcpy(fmr->page_list, page_list, list_len * sizeof(*page_list));
spin_lock_irqsave(&pool->pool_lock, flags);
hlist_add_head(&fmr->cache_node,
pool->cache_bucket + ib_fmr_hash(fmr->page_list[0]));
spin_unlock_irqrestore(&pool->pool_lock, flags);
}
return fmr;
}
EXPORT_SYMBOL(ib_fmr_pool_map_phys);
/**
* ib_fmr_pool_unmap - Unmap FMR
* @fmr:FMR to unmap
*
* Unmap an FMR. The FMR mapping may remain valid until the FMR is
* reused (or until ib_flush_fmr_pool() is called).
*/
int ib_fmr_pool_unmap(struct ib_pool_fmr *fmr)
{
struct ib_fmr_pool *pool;
unsigned long flags;
pool = fmr->pool;
spin_lock_irqsave(&pool->pool_lock, flags);
--fmr->ref_count;
if (!fmr->ref_count) {
if (fmr->remap_count < IB_FMR_MAX_REMAPS) {
list_add_tail(&fmr->list, &pool->free_list);
} else {
list_add_tail(&fmr->list, &pool->dirty_list);
++pool->dirty_len;
wake_up_process(pool->thread);
}
}
#ifdef DEBUG
if (fmr->ref_count < 0)
printk(KERN_WARNING "FMR %p has ref count %d < 0",
fmr, fmr->ref_count);
#endif
spin_unlock_irqrestore(&pool->pool_lock, flags);
return 0;
}
EXPORT_SYMBOL(ib_fmr_pool_unmap);
