-/*
- * 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).
- *
- * You should have received a copy of the GNU General Public License
- * version 2 along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA
- *
- * 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/
- *
- * Author: liang@whamcloud.com
- */
-
-#define DEBUG_SUBSYSTEM S_LNET
-
-#include <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 != NULL);
- LASSERT(!pcl->pcl_locked);
-
- cfs_percpt_free(pcl->pcl_locks);
- LIBCFS_FREE(pcl, sizeof(*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 */
- LIBCFS_ALLOC(pcl, sizeof(*pcl));
- if (pcl == NULL)
- return NULL;
-
- pcl->pcl_cptab = cptab;
- pcl->pcl_locks = cfs_percpt_alloc(cptab, sizeof(*lock));
- if (pcl->pcl_locks == NULL) {
- LIBCFS_FREE(pcl, sizeof(*pcl));
- return NULL;
- }
-
- if (keys == NULL) {
- 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 != NULL)
- 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 == 0) {
- 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 == 0) {
- LASSERT(pcl->pcl_locked);
- pcl->pcl_locked = 0;
- }
- spin_unlock(pcl->pcl_locks[i]);
- }
-}
-EXPORT_SYMBOL(cfs_percpt_unlock);