drivers/infiniband/hw/mlx5/mem.c

   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 two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        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 OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * 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 be
  38  * filled in the pas array.
  39  */
  40 void 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 quantized
  54  * page_offset. The granulatity of the page offset scales according to page
  55  * size.
  56  */
  57 unsigned 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 the
  74          * page_offset fits into the mailbox field. Once page_size < scale this
  75          * 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 the
  85          * 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 }