/* * 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 kthread_worker *worker; struct kthread_work work; 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) { pr_warn(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) pr_warn(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 void ib_fmr_cleanup_func(struct kthread_work *work) { struct ib_fmr_pool *pool = container_of(work, struct ib_fmr_pool, work); 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); if (atomic_read(&pool->flush_ser) - atomic_read(&pool->req_ser) < 0) kthread_queue_work(pool->worker, &pool->work); } /** * 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; 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) { pr_info(PFX "Device %s does not support FMRs\n", device->name); return ERR_PTR(-ENOSYS); } if (!device->attrs.max_map_per_fmr) max_remaps = IB_FMR_MAX_REMAPS; else max_remaps = device->attrs.max_map_per_fmr; pool = kmalloc(sizeof *pool, GFP_KERNEL); if (!pool) 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) { 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->worker = kthread_create_worker(0, "ib_fmr(%s)", device->name); if (IS_ERR(pool->worker)) { pr_warn(PFX "couldn't start cleanup kthread worker\n"); ret = PTR_ERR(pool->worker); goto out_free_pool; } kthread_init_work(&pool->work, ib_fmr_cleanup_func); { 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) 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)) { pr_warn(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_destroy_worker(pool->worker); 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) pr_warn(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); kthread_queue_work(pool->worker, &pool->work); 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); pr_warn(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); kthread_queue_work(pool->worker, &pool->work); } } } #ifdef DEBUG if (fmr->ref_count < 0) pr_warn(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);