brintos

brintos / linux-shallow public Read only

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1/*2 * Copyright (c) 2013-2015, Mellanox Technologies. All rights reserved.3 *4 * This software is available to you under a choice of one of two5 * licenses.  You may choose to be licensed under the terms of the GNU6 * General Public License (GPL) Version 2, available from the file7 * COPYING in the main directory of this source tree, or the8 * OpenIB.org BSD license below:9 *10 *     Redistribution and use in source and binary forms, with or11 *     without modification, are permitted provided that the following12 *     conditions are met:13 *14 *      - Redistributions of source code must retain the above15 *        copyright notice, this list of conditions and the following16 *        disclaimer.17 *18 *      - Redistributions in binary form must reproduce the above19 *        copyright notice, this list of conditions and the following20 *        disclaimer in the documentation and/or other materials21 *        provided with the distribution.22 *23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE30 * SOFTWARE.31 */32 33#include <rdma/ib_umem_odp.h>34#include "mlx5_ib.h"35 36/*37 * Fill in a physical address list. ib_umem_num_dma_blocks() entries will be38 * filled in the pas array.39 */40void mlx5_ib_populate_pas(struct ib_umem *umem, size_t page_size, __be64 *pas,41			  u64 access_flags)42{43	struct ib_block_iter biter;44 45	rdma_umem_for_each_dma_block (umem, &biter, page_size) {46		*pas = cpu_to_be64(rdma_block_iter_dma_address(&biter) |47				   access_flags);48		pas++;49	}50}51 52/*53 * Compute the page shift and page_offset for mailboxes that use a quantized54 * page_offset. The granulatity of the page offset scales according to page55 * size.56 */57unsigned long __mlx5_umem_find_best_quantized_pgoff(58	struct ib_umem *umem, unsigned long pgsz_bitmap,59	unsigned int page_offset_bits, u64 pgoff_bitmask, unsigned int scale,60	unsigned int *page_offset_quantized)61{62	const u64 page_offset_mask = (1UL << page_offset_bits) - 1;63	unsigned long page_size;64	u64 page_offset;65 66	page_size = ib_umem_find_best_pgoff(umem, pgsz_bitmap, pgoff_bitmask);67	if (!page_size)68		return 0;69 70	/*71	 * page size is the largest possible page size.72	 *73	 * Reduce the page_size, and thus the page_offset and quanta, until the74	 * page_offset fits into the mailbox field. Once page_size < scale this75	 * loop is guaranteed to terminate.76	 */77	page_offset = ib_umem_dma_offset(umem, page_size);78	while (page_offset & ~(u64)(page_offset_mask * (page_size / scale))) {79		page_size /= 2;80		page_offset = ib_umem_dma_offset(umem, page_size);81	}82 83	/*84	 * The address is not aligned, or otherwise cannot be represented by the85	 * page_offset.86	 */87	if (!(pgsz_bitmap & page_size))88		return 0;89 90	*page_offset_quantized =91		(unsigned long)page_offset / (page_size / scale);92	if (WARN_ON(*page_offset_quantized > page_offset_mask))93		return 0;94	return page_size;95}96