Commit 3b72422d authored by Yevgeny Kliteynik's avatar Yevgeny Kliteynik Committed by Saeed Mahameed
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net/mlx5: DR, Add buddy allocator utilities 



Add implementation of SW Steering variation of buddy allocator.

The buddy system for ICM memory uses 2 main data structures:
- Bitmap per order, that keeps the current state of allocated
  blocks for this order
- Indicator for the number of available blocks per each order

Signed-off-by: default avatarErez Shitrit <erezsh@nvidia.com>
Signed-off-by: default avatarYevgeny Kliteynik <kliteyn@nvidia.com>
Reviewed-by: default avatarMark Bloch <mbloch@nvidia.com>
Signed-off-by: default avatarSaeed Mahameed <saeedm@nvidia.com>
parent 8a8a1023

drivers/net/ethernet/mellanox/mlx5/core/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -81,7 +81,7 @@ mlx5_core-$(CONFIG_MLX5_EN_TLS) += en_accel/tls.o en_accel/tls_rxtx.o en_accel/t 


mlx5_core-$(CONFIG_MLX5_SW_STEERING) += steering/dr_domain.o steering/dr_table.o \

					steering/dr_matcher.o steering/dr_rule.o \

					steering/dr_icm_pool.o \

					steering/dr_icm_pool.o steering/dr_buddy.o \

					steering/dr_ste.o steering/dr_send.o \

					steering/dr_cmd.o steering/dr_fw.o \

					steering/dr_action.o steering/fs_dr.o

drivers/net/ethernet/mellanox/mlx5/core/steering/dr_buddy.c

0 → 100644
+170 −0
Original line number Diff line number Diff line 
// 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];

}

drivers/net/ethernet/mellanox/mlx5/core/steering/mlx5dr.h

+33 −0
Original line number Diff line number Diff line
@@ -127,4 +127,37 @@ mlx5dr_is_supported(struct mlx5_core_dev *dev) 
	return MLX5_CAP_ESW_FLOWTABLE_FDB(dev, sw_owner);

}



/* buddy functions & structure */



struct mlx5dr_icm_mr;



struct mlx5dr_icm_buddy_mem {

	unsigned long		**bitmap;

	unsigned int		*num_free;

	u32			max_order;

	struct list_head	list_node;

	struct mlx5dr_icm_mr	*icm_mr;

	struct mlx5dr_icm_pool	*pool;



	/* This is the list of used chunks. HW may be accessing this memory */

	struct list_head	used_list;



	/* Hardware may be accessing this memory but at some future,

	 * undetermined time, it might cease to do so.

	 * sync_ste command sets them free.

	 */

	struct list_head	hot_list;

	/* indicates the byte size of hot mem */

	unsigned int		hot_memory_size;

};



int mlx5dr_buddy_init(struct mlx5dr_icm_buddy_mem *buddy,

		      unsigned int max_order);

void mlx5dr_buddy_cleanup(struct mlx5dr_icm_buddy_mem *buddy);

int mlx5dr_buddy_alloc_mem(struct mlx5dr_icm_buddy_mem *buddy,

			   unsigned int order,

			   unsigned int *segment);

void mlx5dr_buddy_free_mem(struct mlx5dr_icm_buddy_mem *buddy,

			   unsigned int seg, unsigned int order);



#endif /* _MLX5DR_H_ */