LXR linux/drivers/infiniband/hw/amso1100/c2

   1/*
   2 * Copyright (c) 2004 Topspin Communications.  All rights reserved.
   3 * Copyright (c) 2005 Open Grid Computing, Inc. All rights reserved.
   4 *
   5 * This software is available to you under a choice of one of two
   6 * licenses.  You may choose to be licensed under the terms of the GNU
   7 * General Public License (GPL) Version 2, available from the file
   8 * COPYING in the main directory of this source tree, or the
   9 * OpenIB.org BSD license below:
  10 *
  11 *     Redistribution and use in source and binary forms, with or
  12 *     without modification, are permitted provided that the following
  13 *     conditions are met:
  14 *
  15 *      - Redistributions of source code must retain the above
  16 *        copyright notice, this list of conditions and the following
  17 *        disclaimer.
  18 *
  19 *      - Redistributions in binary form must reproduce the above
  20 *        copyright notice, this list of conditions and the following
  21 *        disclaimer in the documentation and/or other materials
  22 *        provided with the distribution.
  23 *
  24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31 * SOFTWARE.
  32 */
  33
  34#include <linux/errno.h>
  35#include <linux/slab.h>
  36#include <linux/bitmap.h>
  37
  38#include "c2.h"
  39
  40static int c2_alloc_mqsp_chunk(struct c2_dev *c2dev, gfp_t gfp_mask,
  41                               struct sp_chunk **head)
  42{
  43        int i;
  44        struct sp_chunk *new_head;
  45        dma_addr_t dma_addr;
  46
  47        new_head = dma_alloc_coherent(&c2dev->pcidev->dev, PAGE_SIZE,
  48                                      &dma_addr, gfp_mask);
  49        if (new_head == NULL)
  50                return -ENOMEM;
  51
  52        new_head->dma_addr = dma_addr;
  53        pci_unmap_addr_set(new_head, mapping, new_head->dma_addr);
  54
  55        new_head->next = NULL;
  56        new_head->head = 0;
  57
  58        /* build list where each index is the next free slot */
  59        for (i = 0;
  60             i < (PAGE_SIZE - sizeof(struct sp_chunk) -
  61                  sizeof(u16)) / sizeof(u16) - 1;
  62             i++) {
  63                new_head->shared_ptr[i] = i + 1;
  64        }
  65        /* terminate list */
  66        new_head->shared_ptr[i] = 0xFFFF;
  67
  68        *head = new_head;
  69        return 0;
  70}
  71
  72int c2_init_mqsp_pool(struct c2_dev *c2dev, gfp_t gfp_mask,
  73                      struct sp_chunk **root)
  74{
  75        return c2_alloc_mqsp_chunk(c2dev, gfp_mask, root);
  76}
  77
  78void c2_free_mqsp_pool(struct c2_dev *c2dev, struct sp_chunk *root)
  79{
  80        struct sp_chunk *next;
  81
  82        while (root) {
  83                next = root->next;
  84                dma_free_coherent(&c2dev->pcidev->dev, PAGE_SIZE, root,
  85                                  pci_unmap_addr(root, mapping));
  86                root = next;
  87        }
  88}
  89
  90__be16 *c2_alloc_mqsp(struct c2_dev *c2dev, struct sp_chunk *head,
  91                      dma_addr_t *dma_addr, gfp_t gfp_mask)
  92{
  93        u16 mqsp;
  94
  95        while (head) {
  96                mqsp = head->head;
  97                if (mqsp != 0xFFFF) {
  98                        head->head = head->shared_ptr[mqsp];
  99                        break;
 100                } else if (head->next == NULL) {
 101                        if (c2_alloc_mqsp_chunk(c2dev, gfp_mask, &head->next) ==
 102                            0) {
 103                                head = head->next;
 104                                mqsp = head->head;
 105                                head->head = head->shared_ptr[mqsp];
 106                                break;
 107                        } else
 108                                return NULL;
 109                } else
 110                        head = head->next;
 111        }
 112        if (head) {
 113                *dma_addr = head->dma_addr +
 114                            ((unsigned long) &(head->shared_ptr[mqsp]) -
 115                             (unsigned long) head);
 116                pr_debug("%s addr %p dma_addr %llx\n", __func__,
 117                         &(head->shared_ptr[mqsp]), (unsigned long long) *dma_addr);
 118                return (__force __be16 *) &(head->shared_ptr[mqsp]);
 119        }
 120        return NULL;
 121}
 122
 123void c2_free_mqsp(__be16 *mqsp)
 124{
 125        struct sp_chunk *head;
 126        u16 idx;
 127
 128        /* The chunk containing this ptr begins at the page boundary */
 129        head = (struct sp_chunk *) ((unsigned long) mqsp & PAGE_MASK);
 130
 131        /* Link head to new mqsp */
 132        *mqsp = (__force __be16) head->head;
 133
 134        /* Compute the shared_ptr index */
 135        idx = ((unsigned long) mqsp & ~PAGE_MASK) >> 1;
 136        idx -= (unsigned long) &(((struct sp_chunk *) 0)->shared_ptr[0]) >> 1;
 137
 138        /* Point this index at the head */
 139        head->shared_ptr[idx] = head->head;
 140
 141        /* Point head at this index */
 142        head->head = idx;
 143}
 144