--- /dev/null
+/*
+ * 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.
+ */
+
+#include <linux/errno.h>
+#include <linux/spinlock.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/jhash.h>
+#include <linux/kthread.h>
+
+#include <rdma/ib_fmr_pool.h>
+
+#include "core_priv.h"
+
+#define PFX "fmr_pool: "
+
+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 < pool->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 max_remaps;
+ 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;
+
+ if (!pool->cache_bucket)
+ return NULL;
+
+ bucket = pool->cache_bucket + ib_fmr_hash(*page_list);
+
+ hlist_for_each_entry(fmr, 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 PFX "Unmapping FMR 0x%08x with ref count %d\n",
+ fmr, fmr->ref_count);
+ }
+#endif
+ }
+
+ list_splice_init(&pool->dirty_list, &unmap_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 PFX "ib_unmap_fmr returned %d\n", 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 (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 (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;
+ struct ib_device_attr *attr;
+ int i;
+ int ret;
+ int max_remaps;
+
+ 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_INFO PFX "Device %s does not support FMRs\n",
+ device->name);
+ return ERR_PTR(-ENOSYS);
+ }
+
+ attr = kmalloc(sizeof *attr, GFP_KERNEL);
+ if (!attr) {
+ printk(KERN_WARNING PFX "couldn't allocate device attr struct\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ ret = ib_query_device(device, attr);
+ if (ret) {
+ printk(KERN_WARNING PFX "couldn't query device: %d\n", ret);
+ kfree(attr);
+ return ERR_PTR(ret);
+ }
+
+ if (!attr->max_map_per_fmr)
+ max_remaps = IB_FMR_MAX_REMAPS;
+ else
+ max_remaps = attr->max_map_per_fmr;
+
+ kfree(attr);
+
+ pool = kmalloc(sizeof *pool, GFP_KERNEL);
+ if (!pool) {
+ printk(KERN_WARNING PFX "couldn't allocate pool struct\n");
+ 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 PFX "Failed to allocate cache in pool\n");
+ 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->max_remaps = max_remaps;
+ 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_run(ib_fmr_cleanup_thread,
+ pool,
+ "ib_fmr(%s)",
+ device->name);
+ if (IS_ERR(pool->thread)) {
+ printk(KERN_WARNING PFX "couldn't start cleanup thread\n");
+ ret = PTR_ERR(pool->thread);
+ goto out_free_pool;
+ }
+
+ {
+ struct ib_pool_fmr *fmr;
+ struct ib_fmr_attr fmr_attr = {
+ .max_pages = params->max_pages_per_fmr,
+ .max_maps = pool->max_remaps,
+ .page_shift = params->page_shift
+ };
+ int bytes_per_fmr = sizeof *fmr;
+
+ if (pool->cache_bucket)
+ bytes_per_fmr += params->max_pages_per_fmr * sizeof (u64);
+
+ for (i = 0; i < params->pool_size; ++i) {
+ fmr = kmalloc(bytes_per_fmr, GFP_KERNEL);
+ if (!fmr) {
+ printk(KERN_WARNING PFX "failed to allocate fmr "
+ "struct for FMR %d\n", 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, &fmr_attr);
+ if (IS_ERR(fmr->fmr)) {
+ printk(KERN_WARNING PFX "fmr_create failed "
+ "for FMR %d\n", 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 PFX "pool still has %d regions registered\n",
+ 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;
+ struct ib_pool_fmr *fmr, *next;
+
+ /*
+ * The free_list holds FMRs that may have been used
+ * but have not been remapped enough times to be dirty.
+ * Put them on the dirty list now so that the cleanup
+ * thread will reap them too.
+ */
+ spin_lock_irq(&pool->pool_lock);
+ list_for_each_entry_safe(fmr, next, &pool->free_list, list) {
+ if (fmr->remap_count > 0)
+ list_move(&fmr->list, &pool->dirty_list);
+ }
+ spin_unlock_irq(&pool->pool_lock);
+
+ serial = atomic_inc_return(&pool->req_ser);
+ wake_up_process(pool->thread);
+
+ if (wait_event_interruptible(pool->force_wait,
+ atomic_read(&pool->flush_ser) - serial >= 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 PFX "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 < pool->max_remaps) {
+ list_add_tail(&fmr->list, &pool->free_list);
+ } else {
+ list_add_tail(&fmr->list, &pool->dirty_list);
+ if (++pool->dirty_len >= pool->dirty_watermark) {
+ atomic_inc(&pool->req_ser);
+ wake_up_process(pool->thread);
+ }
+ }
+ }
+
+#ifdef DEBUG
+ if (fmr->ref_count < 0)
+ printk(KERN_WARNING PFX "FMR %p has ref count %d < 0\n",
+ fmr, fmr->ref_count);
+#endif
+
+ spin_unlock_irqrestore(&pool->pool_lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL(ib_fmr_pool_unmap);
Code Review / kvmfornfv.git / blobdiff