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
c2_alloc_mqsp_chunk(struct c2_dev * c2dev,gfp_t gfp_mask,struct sp_chunk ** head)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
c2_init_mqsp_pool(struct c2_dev * c2dev,gfp_t gfp_mask,struct sp_chunk ** root)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
c2_free_mqsp_pool(struct c2_dev * c2dev,struct sp_chunk * root)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
c2_alloc_mqsp(struct c2_dev * c2dev,struct sp_chunk * head,dma_addr_t * dma_addr,gfp_t gfp_mask)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
c2_free_mqsp(__be16 * mqsp)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 }
143