From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/infiniband/hw/cxgb4/id_table.c | 106 +++++++++++++++++++++++++++++++++ 1 file changed, 106 insertions(+) create mode 100644 drivers/infiniband/hw/cxgb4/id_table.c (limited to 'drivers/infiniband/hw/cxgb4/id_table.c') diff --git a/drivers/infiniband/hw/cxgb4/id_table.c b/drivers/infiniband/hw/cxgb4/id_table.c new file mode 100644 index 0000000000..e2188b335e --- /dev/null +++ b/drivers/infiniband/hw/cxgb4/id_table.c @@ -0,0 +1,106 @@ +/* + * Copyright (c) 2011 Chelsio Communications. 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 +#include +#include "iw_cxgb4.h" + +#define RANDOM_SKIP 16 + +/* + * Trivial bitmap-based allocator. If the random flag is set, the + * allocator is designed to: + * - pseudo-randomize the id returned such that it is not trivially predictable. + * - avoid reuse of recently used id (at the expense of predictability) + */ +u32 c4iw_id_alloc(struct c4iw_id_table *alloc) +{ + unsigned long flags; + u32 obj; + + spin_lock_irqsave(&alloc->lock, flags); + + obj = find_next_zero_bit(alloc->table, alloc->max, alloc->last); + if (obj >= alloc->max) + obj = find_first_zero_bit(alloc->table, alloc->max); + + if (obj < alloc->max) { + if (alloc->flags & C4IW_ID_TABLE_F_RANDOM) + alloc->last += get_random_u32_below(RANDOM_SKIP); + else + alloc->last = obj + 1; + if (alloc->last >= alloc->max) + alloc->last = 0; + __set_bit(obj, alloc->table); + obj += alloc->start; + } else + obj = -1; + + spin_unlock_irqrestore(&alloc->lock, flags); + return obj; +} + +void c4iw_id_free(struct c4iw_id_table *alloc, u32 obj) +{ + unsigned long flags; + + obj -= alloc->start; + + spin_lock_irqsave(&alloc->lock, flags); + __clear_bit(obj, alloc->table); + spin_unlock_irqrestore(&alloc->lock, flags); +} + +int c4iw_id_table_alloc(struct c4iw_id_table *alloc, u32 start, u32 num, + u32 reserved, u32 flags) +{ + alloc->start = start; + alloc->flags = flags; + if (flags & C4IW_ID_TABLE_F_RANDOM) + alloc->last = get_random_u32_below(RANDOM_SKIP); + else + alloc->last = 0; + alloc->max = num; + spin_lock_init(&alloc->lock); + alloc->table = bitmap_zalloc(num, GFP_KERNEL); + if (!alloc->table) + return -ENOMEM; + + if (!(alloc->flags & C4IW_ID_TABLE_F_EMPTY)) + bitmap_set(alloc->table, 0, reserved); + + return 0; +} + +void c4iw_id_table_free(struct c4iw_id_table *alloc) +{ + bitmap_free(alloc->table); +} -- cgit v1.2.3