drivers/infiniband/hw/amso1100/c2_alloc.c

   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
  40 static 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
  72 int 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
  78 void 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 u16 *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", __FUNCTION__,
 117                          &(head->shared_ptr[mqsp]), (unsigned long long) *dma_addr);
 118                 return &(head->shared_ptr[mqsp]);
 119         }
 120         return NULL;
 121 }
 122
 123 void c2_free_mqsp(u16 * 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 = 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 }