/* * lib/parman.c - Manager for linear priority array areas * Copyright (c) 2017 Mellanox Technologies. All rights reserved. * Copyright (c) 2017 Jiri Pirko <[email protected]> * * 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 <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/export.h> #include <linux/list.h> #include <linux/err.h> #include <linux/parman.h> struct parman_algo { … }; struct parman { … }; static int parman_enlarge(struct parman *parman) { … } static int parman_shrink(struct parman *parman) { … } static bool parman_prio_used(struct parman_prio *prio) { … } static struct parman_item *parman_prio_first_item(struct parman_prio *prio) { … } static unsigned long parman_prio_first_index(struct parman_prio *prio) { … } static struct parman_item *parman_prio_last_item(struct parman_prio *prio) { … } static unsigned long parman_prio_last_index(struct parman_prio *prio) { … } static unsigned long parman_lsort_new_index_find(struct parman *parman, struct parman_prio *prio) { … } static void __parman_prio_move(struct parman *parman, struct parman_prio *prio, struct parman_item *item, unsigned long to_index, unsigned long count) { … } static void parman_prio_shift_down(struct parman *parman, struct parman_prio *prio) { … } static void parman_prio_shift_up(struct parman *parman, struct parman_prio *prio) { … } static void parman_prio_item_remove(struct parman *parman, struct parman_prio *prio, struct parman_item *item) { … } static int parman_lsort_item_add(struct parman *parman, struct parman_prio *prio, struct parman_item *item) { … } static void parman_lsort_item_remove(struct parman *parman, struct parman_prio *prio, struct parman_item *item) { … } static const struct parman_algo parman_lsort = …; static const struct parman_algo *parman_algos[] = …; /** * parman_create - creates a new parman instance * @ops: caller-specific callbacks * @priv: pointer to a private data passed to the ops * * Note: all locking must be provided by the caller. * * Each parman instance manages an array area with chunks of entries * with the same priority. Consider following example: * * item 1 with prio 10 * item 2 with prio 10 * item 3 with prio 10 * item 4 with prio 20 * item 5 with prio 20 * item 6 with prio 30 * item 7 with prio 30 * item 8 with prio 30 * * In this example, there are 3 priority chunks. The order of the priorities * matters, however the order of items within a single priority chunk does not * matter. So the same array could be ordered as follows: * * item 2 with prio 10 * item 3 with prio 10 * item 1 with prio 10 * item 5 with prio 20 * item 4 with prio 20 * item 7 with prio 30 * item 8 with prio 30 * item 6 with prio 30 * * The goal of parman is to maintain the priority ordering. The caller * provides @ops with callbacks parman uses to move the items * and resize the array area. * * Returns a pointer to newly created parman instance in case of success, * otherwise it returns NULL. */ struct parman *parman_create(const struct parman_ops *ops, void *priv) { … } EXPORT_SYMBOL(…); /** * parman_destroy - destroys existing parman instance * @parman: parman instance * * Note: all locking must be provided by the caller. */ void parman_destroy(struct parman *parman) { … } EXPORT_SYMBOL(…); /** * parman_prio_init - initializes a parman priority chunk * @parman: parman instance * @prio: parman prio structure to be initialized * @priority: desired priority of the chunk * * Note: all locking must be provided by the caller. * * Before caller could add an item with certain priority, he has to * initialize a priority chunk for it using this function. */ void parman_prio_init(struct parman *parman, struct parman_prio *prio, unsigned long priority) { … } EXPORT_SYMBOL(…); /** * parman_prio_fini - finalizes use of parman priority chunk * @prio: parman prio structure * * Note: all locking must be provided by the caller. */ void parman_prio_fini(struct parman_prio *prio) { … } EXPORT_SYMBOL(…); /** * parman_item_add - adds a parman item under defined priority * @parman: parman instance * @prio: parman prio instance to add the item to * @item: parman item instance * * Note: all locking must be provided by the caller. * * Adds item to a array managed by parman instance under the specified priority. * * Returns 0 in case of success, negative number to indicate an error. */ int parman_item_add(struct parman *parman, struct parman_prio *prio, struct parman_item *item) { … } EXPORT_SYMBOL(…); /** * parman_item_remove - deletes parman item * @parman: parman instance * @prio: parman prio instance to delete the item from * @item: parman item instance * * Note: all locking must be provided by the caller. */ void parman_item_remove(struct parman *parman, struct parman_prio *prio, struct parman_item *item) { … } EXPORT_SYMBOL(…); MODULE_LICENSE(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …;
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