RDMA/core: Remove FMR pool API

This ancient and unsafe method for memory registration is no longer used
by any RDMA based ULP. Remove the FMR pool API from the core driver.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Max Gurtovoy <[e-mail]>
Signed-off-by: Jason Gunthorpe <[e-mail]>

Documentation/driver-api/infiniband.rst

···
 .. kernel-doc:: drivers/infiniband/core/ud_header.c
     :export:
 
-.. kernel-doc:: drivers/infiniband/core/fmr_pool.c
-    :export:
-
 .. kernel-doc:: drivers/infiniband/core/umem.c
     :export:
 

drivers/infiniband/core/Makefile

···
 obj-$(CONFIG_INFINIBAND_USER_ACCESS) += ib_uverbs.o $(user_access-y)
 
 ib_core-y :=			packer.o ud_header.o verbs.o cq.o rw.o sysfs.o \
-				device.o fmr_pool.o cache.o netlink.o \
+				device.o cache.o netlink.o \
 				roce_gid_mgmt.o mr_pool.o addr.o sa_query.o \
 				multicast.o mad.o smi.o agent.o mad_rmpp.o \
 				nldev.o restrack.o counters.o ib_core_uverbs.o \

drivers/infiniband/core/fmr_pool.c

···
-/*
- * 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);
-	}
-
-	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->ops.alloc_fmr    || !device->ops.dealloc_fmr  ||
-	    !device->ops.map_phys_fmr || !device->ops.unmap_fmr) {
-		dev_info(&device->dev, "Device does not support FMRs\n");
-		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_array(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)", dev_name(&device->dev));
-	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 - Map an FMR from an FMR pool.
- * @pool_handle: 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
- */
-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).
- */
-void 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);
-			}
-		}
-	}
-
-	spin_unlock_irqrestore(&pool->pool_lock, flags);
-}
-EXPORT_SYMBOL(ib_fmr_pool_unmap);

include/rdma/ib_fmr_pool.h

···
-/*
- * Copyright (c) 2004 Topspin Corporation.  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.
- */
-
-#if !defined(IB_FMR_POOL_H)
-#define IB_FMR_POOL_H
-
-#include <rdma/ib_verbs.h>
-
-struct ib_fmr_pool;
-
-/**
- * struct ib_fmr_pool_param - Parameters for creating FMR pool
- * @max_pages_per_fmr:Maximum number of pages per map request.
- * @page_shift: Log2 of sizeof "pages" mapped by this fmr
- * @access:Access flags for FMRs in pool.
- * @pool_size:Number of FMRs to allocate for pool.
- * @dirty_watermark:Flush is triggered when @dirty_watermark dirty
- *     FMRs are present.
- * @flush_function:Callback called when unmapped FMRs are flushed and
- *     more FMRs are possibly available for mapping
- * @flush_arg:Context passed to user's flush function.
- * @cache:If set, FMRs may be reused after unmapping for identical map
- *     requests.
- */
-struct ib_fmr_pool_param {
-	int                     max_pages_per_fmr;
-	int                     page_shift;
-	enum ib_access_flags    access;
-	int                     pool_size;
-	int                     dirty_watermark;
-	void                  (*flush_function)(struct ib_fmr_pool *pool,
-						void               *arg);
-	void                   *flush_arg;
-	unsigned                cache:1;
-};
-
-struct ib_pool_fmr {
-	struct ib_fmr      *fmr;
-	struct ib_fmr_pool *pool;
-	struct list_head    list;
-	struct hlist_node   cache_node;
-	int                 ref_count;
-	int                 remap_count;
-	u64                 io_virtual_address;
-	int                 page_list_len;
-	u64                 page_list[];
-};
-
-struct ib_fmr_pool *ib_create_fmr_pool(struct ib_pd             *pd,
-				       struct ib_fmr_pool_param *params);
-
-void ib_destroy_fmr_pool(struct ib_fmr_pool *pool);
-
-int ib_flush_fmr_pool(struct ib_fmr_pool *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);
-
-void ib_fmr_pool_unmap(struct ib_pool_fmr *fmr);
-
-#endif /* IB_FMR_POOL_H */