diff options
Diffstat (limited to 'drivers/net/ethernet/mellanox/mlx5/core/steering/dr_buddy.c')
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx5/core/steering/dr_buddy.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_buddy.c b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_buddy.c new file mode 100644 index 000000000000..7df11a019df9 --- /dev/null +++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_buddy.c @@ -0,0 +1,170 @@ +// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB +/* Copyright (c) 2004 Topspin Communications. All rights reserved. + * Copyright (c) 2005 - 2008 Mellanox Technologies. All rights reserved. + * Copyright (c) 2006 - 2007 Cisco Systems, Inc. All rights reserved. + * Copyright (c) 2020 NVIDIA CORPORATION. All rights reserved. + */ + +#include "dr_types.h" + +int mlx5dr_buddy_init(struct mlx5dr_icm_buddy_mem *buddy, + unsigned int max_order) +{ + int i; + + buddy->max_order = max_order; + + INIT_LIST_HEAD(&buddy->list_node); + INIT_LIST_HEAD(&buddy->used_list); + INIT_LIST_HEAD(&buddy->hot_list); + + buddy->bitmap = kcalloc(buddy->max_order + 1, + sizeof(*buddy->bitmap), + GFP_KERNEL); + buddy->num_free = kcalloc(buddy->max_order + 1, + sizeof(*buddy->num_free), + GFP_KERNEL); + + if (!buddy->bitmap || !buddy->num_free) + goto err_free_all; + + /* Allocating max_order bitmaps, one for each order */ + + for (i = 0; i <= buddy->max_order; ++i) { + unsigned int size = 1 << (buddy->max_order - i); + + buddy->bitmap[i] = bitmap_zalloc(size, GFP_KERNEL); + if (!buddy->bitmap[i]) + goto err_out_free_each_bit_per_order; + } + + /* In the beginning, we have only one order that is available for + * use (the biggest one), so mark the first bit in both bitmaps. + */ + + bitmap_set(buddy->bitmap[buddy->max_order], 0, 1); + + buddy->num_free[buddy->max_order] = 1; + + return 0; + +err_out_free_each_bit_per_order: + for (i = 0; i <= buddy->max_order; ++i) + bitmap_free(buddy->bitmap[i]); + +err_free_all: + kfree(buddy->num_free); + kfree(buddy->bitmap); + return -ENOMEM; +} + +void mlx5dr_buddy_cleanup(struct mlx5dr_icm_buddy_mem *buddy) +{ + int i; + + list_del(&buddy->list_node); + + for (i = 0; i <= buddy->max_order; ++i) + bitmap_free(buddy->bitmap[i]); + + kfree(buddy->num_free); + kfree(buddy->bitmap); +} + +static int dr_buddy_find_free_seg(struct mlx5dr_icm_buddy_mem *buddy, + unsigned int start_order, + unsigned int *segment, + unsigned int *order) +{ + unsigned int seg, order_iter, m; + + for (order_iter = start_order; + order_iter <= buddy->max_order; ++order_iter) { + if (!buddy->num_free[order_iter]) + continue; + + m = 1 << (buddy->max_order - order_iter); + seg = find_first_bit(buddy->bitmap[order_iter], m); + + if (WARN(seg >= m, + "ICM Buddy: failed finding free mem for order %d\n", + order_iter)) + return -ENOMEM; + + break; + } + + if (order_iter > buddy->max_order) + return -ENOMEM; + + *segment = seg; + *order = order_iter; + return 0; +} + +/** + * mlx5dr_buddy_alloc_mem() - Update second level bitmap. + * @buddy: Buddy to update. + * @order: Order of the buddy to update. + * @segment: Segment number. + * + * This function finds the first area of the ICM memory managed by this buddy. + * It uses the data structures of the buddy system in order to find the first + * area of free place, starting from the current order till the maximum order + * in the system. + * + * Return: 0 when segment is set, non-zero error status otherwise. + * + * The function returns the location (segment) in the whole buddy ICM memory + * area - the index of the memory segment that is available for use. + */ +int mlx5dr_buddy_alloc_mem(struct mlx5dr_icm_buddy_mem *buddy, + unsigned int order, + unsigned int *segment) +{ + unsigned int seg, order_iter; + int err; + + err = dr_buddy_find_free_seg(buddy, order, &seg, &order_iter); + if (err) + return err; + + bitmap_clear(buddy->bitmap[order_iter], seg, 1); + --buddy->num_free[order_iter]; + + /* If we found free memory in some order that is bigger than the + * required order, we need to split every order between the required + * order and the order that we found into two parts, and mark accordingly. + */ + while (order_iter > order) { + --order_iter; + seg <<= 1; + bitmap_set(buddy->bitmap[order_iter], seg ^ 1, 1); + ++buddy->num_free[order_iter]; + } + + seg <<= order; + *segment = seg; + + return 0; +} + +void mlx5dr_buddy_free_mem(struct mlx5dr_icm_buddy_mem *buddy, + unsigned int seg, unsigned int order) +{ + seg >>= order; + + /* Whenever a segment is free, + * the mem is added to the buddy that gave it. + */ + while (test_bit(seg ^ 1, buddy->bitmap[order])) { + bitmap_clear(buddy->bitmap[order], seg ^ 1, 1); + --buddy->num_free[order]; + seg >>= 1; + ++order; + } + bitmap_set(buddy->bitmap[order], seg, 1); + + ++buddy->num_free[order]; +} + |