diff options
Diffstat (limited to 'drivers/staging/lustre/lnet/libcfs/libcfs_lock.c')
| -rw-r--r-- | drivers/staging/lustre/lnet/libcfs/libcfs_lock.c | 152 |
1 files changed, 0 insertions, 152 deletions
diff --git a/drivers/staging/lustre/lnet/libcfs/libcfs_lock.c b/drivers/staging/lustre/lnet/libcfs/libcfs_lock.c deleted file mode 100644 index 670ad5a34224..000000000000 --- a/drivers/staging/lustre/lnet/libcfs/libcfs_lock.c +++ /dev/null @@ -1,152 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * GPL HEADER START - * - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 only, - * as published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License version 2 for more details (a copy is included - * in the LICENSE file that accompanied this code). - * - * GPL HEADER END - */ -/* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2012, 2015 Intel Corporation. - */ -/* - * This file is part of Lustre, http://www.lustre.org/ - * Lustre is a trademark of Sun Microsystems, Inc. - * - * Author: liang@whamcloud.com - */ - -#define DEBUG_SUBSYSTEM S_LNET - -#include <linux/libcfs/libcfs.h> - -/** destroy cpu-partition lock, see libcfs_private.h for more detail */ -void -cfs_percpt_lock_free(struct cfs_percpt_lock *pcl) -{ - LASSERT(pcl->pcl_locks); - LASSERT(!pcl->pcl_locked); - - cfs_percpt_free(pcl->pcl_locks); - kfree(pcl); -} -EXPORT_SYMBOL(cfs_percpt_lock_free); - -/** - * create cpu-partition lock, see libcfs_private.h for more detail. - * - * cpu-partition lock is designed for large-scale SMP system, so we need to - * reduce cacheline conflict as possible as we can, that's the - * reason we always allocate cacheline-aligned memory block. - */ -struct cfs_percpt_lock * -cfs_percpt_lock_create(struct cfs_cpt_table *cptab, - struct lock_class_key *keys) -{ - struct cfs_percpt_lock *pcl; - spinlock_t *lock; - int i; - - /* NB: cptab can be NULL, pcl will be for HW CPUs on that case */ - pcl = kzalloc(sizeof(*pcl), GFP_NOFS); - if (!pcl) - return NULL; - - pcl->pcl_cptab = cptab; - pcl->pcl_locks = cfs_percpt_alloc(cptab, sizeof(*lock)); - if (!pcl->pcl_locks) { - kfree(pcl); - return NULL; - } - - if (!keys) - CWARN("Cannot setup class key for percpt lock, you may see recursive locking warnings which are actually fake.\n"); - - cfs_percpt_for_each(lock, i, pcl->pcl_locks) { - spin_lock_init(lock); - if (keys) - lockdep_set_class(lock, &keys[i]); - } - - return pcl; -} -EXPORT_SYMBOL(cfs_percpt_lock_create); - -/** - * lock a CPU partition - * - * \a index != CFS_PERCPT_LOCK_EX - * hold private lock indexed by \a index - * - * \a index == CFS_PERCPT_LOCK_EX - * exclusively lock @pcl and nobody can take private lock - */ -void -cfs_percpt_lock(struct cfs_percpt_lock *pcl, int index) - __acquires(pcl->pcl_locks) -{ - int ncpt = cfs_cpt_number(pcl->pcl_cptab); - int i; - - LASSERT(index >= CFS_PERCPT_LOCK_EX && index < ncpt); - - if (ncpt == 1) { - index = 0; - } else { /* serialize with exclusive lock */ - while (pcl->pcl_locked) - cpu_relax(); - } - - if (likely(index != CFS_PERCPT_LOCK_EX)) { - spin_lock(pcl->pcl_locks[index]); - return; - } - - /* exclusive lock request */ - for (i = 0; i < ncpt; i++) { - spin_lock(pcl->pcl_locks[i]); - if (!i) { - LASSERT(!pcl->pcl_locked); - /* nobody should take private lock after this - * so I wouldn't starve for too long time - */ - pcl->pcl_locked = 1; - } - } -} -EXPORT_SYMBOL(cfs_percpt_lock); - -/** unlock a CPU partition */ -void -cfs_percpt_unlock(struct cfs_percpt_lock *pcl, int index) - __releases(pcl->pcl_locks) -{ - int ncpt = cfs_cpt_number(pcl->pcl_cptab); - int i; - - index = ncpt == 1 ? 0 : index; - - if (likely(index != CFS_PERCPT_LOCK_EX)) { - spin_unlock(pcl->pcl_locks[index]); - return; - } - - for (i = ncpt - 1; i >= 0; i--) { - if (!i) { - LASSERT(pcl->pcl_locked); - pcl->pcl_locked = 0; - } - spin_unlock(pcl->pcl_locks[i]); - } -} -EXPORT_SYMBOL(cfs_percpt_unlock); |