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/bitmap.h>
  36
  37 #include "c2.h"
  38
  39 static int c2_alloc_mqsp_chunk(struct c2_dev *c2dev, gfp_t gfp_mask,
  40                                struct sp_chunk **head)
  41 {
  42         int i;
  43         struct sp_chunk *new_head;
  44         dma_addr_t dma_addr;
  45
  46         new_head = dma_alloc_coherent(&c2dev->pcidev->dev, PAGE_SIZE,
  47                                       &dma_addr, gfp_mask);
  48         if (new_head == NULL)
  49                 return -ENOMEM;
  50
  51         new_head->dma_addr = dma_addr;
  52         dma_unmap_addr_set(new_head, mapping, new_head->dma_addr);
  53
  54         new_head->next = NULL;
  55         new_head->head = 0;
  56
  57         /* build list where each index is the next free slot */
  58         for (i = 0;
  59              i < (PAGE_SIZE - sizeof(struct sp_chunk) -
  60                   sizeof(u16)) / sizeof(u16) - 1;
  61              i++) {
  62                 new_head->shared_ptr[i] = i + 1;
  63         }
  64         /* terminate list */
  65         new_head->shared_ptr[i] = 0xFFFF;
  66
  67         *head = new_head;
  68         return 0;
  69 }
  70
  71 int c2_init_mqsp_pool(struct c2_dev *c2dev, gfp_t gfp_mask,
  72                       struct sp_chunk **root)
  73 {
  74         return c2_alloc_mqsp_chunk(c2dev, gfp_mask, root);
  75 }
  76
  77 void c2_free_mqsp_pool(struct c2_dev *c2dev, struct sp_chunk *root)
  78 {
  79         struct sp_chunk *next;
  80
  81         while (root) {
  82                 next = root->next;
  83                 dma_free_coherent(&c2dev->pcidev->dev, PAGE_SIZE, root,
  84                                   dma_unmap_addr(root, mapping));
  85                 root = next;
  86         }
  87 }
  88
  89 __be16 *c2_alloc_mqsp(struct c2_dev *c2dev, struct sp_chunk *head,
  90                       dma_addr_t *dma_addr, gfp_t gfp_mask)
  91 {
  92         u16 mqsp;
  93
  94         while (head) {
  95                 mqsp = head->head;
  96                 if (mqsp != 0xFFFF) {
  97                         head->head = head->shared_ptr[mqsp];
  98                         break;
  99                 } else if (head->next == NULL) {
 100                         if (c2_alloc_mqsp_chunk(c2dev, gfp_mask, &head->next) ==
 101                             0) {
 102                                 head = head->next;
 103                                 mqsp = head->head;
 104                                 head->head = head->shared_ptr[mqsp];
 105                                 break;
 106                         } else
 107                                 return NULL;
 108                 } else
 109                         head = head->next;
 110         }
 111         if (head) {
 112                 *dma_addr = head->dma_addr +
 113                             ((unsigned long) &(head->shared_ptr[mqsp]) -
 114                              (unsigned long) head);
 115                 pr_debug("%s addr %p dma_addr %llx\n", __func__,
 116                          &(head->shared_ptr[mqsp]), (unsigned long long) *dma_addr);
 117                 return (__force __be16 *) &(head->shared_ptr[mqsp]);
 118         }
 119         return NULL;
 120 }
 121
 122 void c2_free_mqsp(__be16 *mqsp)
 123 {
 124         struct sp_chunk *head;
 125         u16 idx;
 126
 127         /* The chunk containing this ptr begins at the page boundary */
 128         head = (struct sp_chunk *) ((unsigned long) mqsp & PAGE_MASK);
 129
 130         /* Link head to new mqsp */
 131         *mqsp = (__force __be16) head->head;
 132
 133         /* Compute the shared_ptr index */
 134         idx = ((unsigned long) mqsp & ~PAGE_MASK) >> 1;
 135         idx -= (unsigned long) &(((struct sp_chunk *) 0)->shared_ptr[0]) >> 1;
 136
 137         /* Point this index at the head */
 138         head->shared_ptr[idx] = head->head;
 139
 140         /* Point head at this index */
 141         head->head = idx;
 142 }