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diff --git a/net/tipc/ref.c b/net/tipc/ref.c
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-/*
- * net/tipc/ref.c: TIPC object registry code
- *
- * Copyright (c) 1991-2006, Ericsson AB
- * Copyright (c) 2004-2007, Wind River Systems
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. 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.
- * 3. Neither the names of the copyright holders nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * Alternatively, this software may be distributed under the terms of the
- * GNU General Public License ("GPL") version 2 as published by the Free
- * Software Foundation.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "core.h"
-#include "ref.h"
-
-/**
- * struct reference - TIPC object reference entry
- * @object: pointer to object associated with reference entry
- * @lock: spinlock controlling access to object
- * @ref: reference value for object (combines instance & array index info)
- */
-struct reference {
- void *object;
- spinlock_t lock;
- u32 ref;
-};
-
-/**
- * struct tipc_ref_table - table of TIPC object reference entries
- * @entries: pointer to array of reference entries
- * @capacity: array index of first unusable entry
- * @init_point: array index of first uninitialized entry
- * @first_free: array index of first unused object reference entry
- * @last_free: array index of last unused object reference entry
- * @index_mask: bitmask for array index portion of reference values
- * @start_mask: initial value for instance value portion of reference values
- */
-struct ref_table {
- struct reference *entries;
- u32 capacity;
- u32 init_point;
- u32 first_free;
- u32 last_free;
- u32 index_mask;
- u32 start_mask;
-};
-
-/*
- * Object reference table consists of 2**N entries.
- *
- * State Object ptr Reference
- * ----- ---------- ---------
- * In use non-NULL XXXX|own index
- * (XXXX changes each time entry is acquired)
- * Free NULL YYYY|next free index
- * (YYYY is one more than last used XXXX)
- * Uninitialized NULL 0
- *
- * Entry 0 is not used; this allows index 0 to denote the end of the free list.
- *
- * Note that a reference value of 0 does not necessarily indicate that an
- * entry is uninitialized, since the last entry in the free list could also
- * have a reference value of 0 (although this is unlikely).
- */
-
-static struct ref_table tipc_ref_table;
-
-static DEFINE_SPINLOCK(ref_table_lock);
-
-/**
- * tipc_ref_table_init - create reference table for objects
- */
-int tipc_ref_table_init(u32 requested_size, u32 start)
-{
- struct reference *table;
- u32 actual_size;
-
- /* account for unused entry, then round up size to a power of 2 */
-
- requested_size++;
- for (actual_size = 16; actual_size < requested_size; actual_size <<= 1)
- /* do nothing */ ;
-
- /* allocate table & mark all entries as uninitialized */
- table = vzalloc(actual_size * sizeof(struct reference));
- if (table == NULL)
- return -ENOMEM;
-
- tipc_ref_table.entries = table;
- tipc_ref_table.capacity = requested_size;
- tipc_ref_table.init_point = 1;
- tipc_ref_table.first_free = 0;
- tipc_ref_table.last_free = 0;
- tipc_ref_table.index_mask = actual_size - 1;
- tipc_ref_table.start_mask = start & ~tipc_ref_table.index_mask;
-
- return 0;
-}
-
-/**
- * tipc_ref_table_stop - destroy reference table for objects
- */
-void tipc_ref_table_stop(void)
-{
- vfree(tipc_ref_table.entries);
- tipc_ref_table.entries = NULL;
-}
-
-/**
- * tipc_ref_acquire - create reference to an object
- *
- * Register an object pointer in reference table and lock the object.
- * Returns a unique reference value that is used from then on to retrieve the
- * object pointer, or to determine that the object has been deregistered.
- *
- * Note: The object is returned in the locked state so that the caller can
- * register a partially initialized object, without running the risk that
- * the object will be accessed before initialization is complete.
- */
-u32 tipc_ref_acquire(void *object, spinlock_t **lock)
-{
- u32 index;
- u32 index_mask;
- u32 next_plus_upper;
- u32 ref;
- struct reference *entry = NULL;
-
- if (!object) {
- pr_err("Attempt to acquire ref. to non-existent obj\n");
- return 0;
- }
- if (!tipc_ref_table.entries) {
- pr_err("Ref. table not found in acquisition attempt\n");
- return 0;
- }
-
- /* take a free entry, if available; otherwise initialize a new entry */
- spin_lock_bh(&ref_table_lock);
- if (tipc_ref_table.first_free) {
- index = tipc_ref_table.first_free;
- entry = &(tipc_ref_table.entries[index]);
- index_mask = tipc_ref_table.index_mask;
- next_plus_upper = entry->ref;
- tipc_ref_table.first_free = next_plus_upper & index_mask;
- ref = (next_plus_upper & ~index_mask) + index;
- } else if (tipc_ref_table.init_point < tipc_ref_table.capacity) {
- index = tipc_ref_table.init_point++;
- entry = &(tipc_ref_table.entries[index]);
- spin_lock_init(&entry->lock);
- ref = tipc_ref_table.start_mask + index;
- } else {
- ref = 0;
- }
- spin_unlock_bh(&ref_table_lock);
-
- /*
- * Grab the lock so no one else can modify this entry
- * While we assign its ref value & object pointer
- */
- if (entry) {
- spin_lock_bh(&entry->lock);
- entry->ref = ref;
- entry->object = object;
- *lock = &entry->lock;
- /*
- * keep it locked, the caller is responsible
- * for unlocking this when they're done with it
- */
- }
-
- return ref;
-}
-
-/**
- * tipc_ref_discard - invalidate references to an object
- *
- * Disallow future references to an object and free up the entry for re-use.
- * Note: The entry's spin_lock may still be busy after discard
- */
-void tipc_ref_discard(u32 ref)
-{
- struct reference *entry;
- u32 index;
- u32 index_mask;
-
- if (!tipc_ref_table.entries) {
- pr_err("Ref. table not found during discard attempt\n");
- return;
- }
-
- index_mask = tipc_ref_table.index_mask;
- index = ref & index_mask;
- entry = &(tipc_ref_table.entries[index]);
-
- spin_lock_bh(&ref_table_lock);
-
- if (!entry->object) {
- pr_err("Attempt to discard ref. to non-existent obj\n");
- goto exit;
- }
- if (entry->ref != ref) {
- pr_err("Attempt to discard non-existent reference\n");
- goto exit;
- }
-
- /*
- * mark entry as unused; increment instance part of entry's reference
- * to invalidate any subsequent references
- */
- entry->object = NULL;
- entry->ref = (ref & ~index_mask) + (index_mask + 1);
-
- /* append entry to free entry list */
- if (tipc_ref_table.first_free == 0)
- tipc_ref_table.first_free = index;
- else
- tipc_ref_table.entries[tipc_ref_table.last_free].ref |= index;
- tipc_ref_table.last_free = index;
-
-exit:
- spin_unlock_bh(&ref_table_lock);
-}
-
-/**
- * tipc_ref_lock - lock referenced object and return pointer to it
- */
-void *tipc_ref_lock(u32 ref)
-{
- if (likely(tipc_ref_table.entries)) {
- struct reference *entry;
-
- entry = &tipc_ref_table.entries[ref &
- tipc_ref_table.index_mask];
- if (likely(entry->ref != 0)) {
- spin_lock_bh(&entry->lock);
- if (likely((entry->ref == ref) && (entry->object)))
- return entry->object;
- spin_unlock_bh(&entry->lock);
- }
- }
- return NULL;
-}