1 /*
2 * Copyright (c) 2016-2019, Intel Corporation
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * * Redistributions of source code must retain the above copyright notice,
8 * this list of conditions and the following disclaimer.
9 * * Redistributions in binary form must reproduce the above copyright notice,
10 * this list of conditions and the following disclaimer in the documentation
11 * and/or other materials provided with the distribution.
12 * * Neither the name of Intel Corporation nor the names of its contributors
13 * may be used to endorse or promote products derived from this software
14 * without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include "pt_block_cache.h"
30
31 #include <stdlib.h>
32 #include <string.h>
33
34
pt_bcache_alloc(uint64_t nentries)35 struct pt_block_cache *pt_bcache_alloc(uint64_t nentries)
36 {
37 struct pt_block_cache *bcache;
38 uint64_t size;
39
40 if (!nentries || (UINT32_MAX < nentries))
41 return NULL;
42
43 size = sizeof(*bcache) + (nentries * sizeof(struct pt_bcache_entry));
44 if (SIZE_MAX < size)
45 return NULL;
46
47 bcache = malloc((size_t) size);
48 if (!bcache)
49 return NULL;
50
51 memset(bcache, 0, (size_t) size);
52 bcache->nentries = (uint32_t) nentries;
53
54 return bcache;
55 }
56
pt_bcache_free(struct pt_block_cache * bcache)57 void pt_bcache_free(struct pt_block_cache *bcache)
58 {
59 free(bcache);
60 }
61
pt_bcache_add(struct pt_block_cache * bcache,uint64_t index,struct pt_bcache_entry bce)62 int pt_bcache_add(struct pt_block_cache *bcache, uint64_t index,
63 struct pt_bcache_entry bce)
64 {
65 if (!bcache)
66 return -pte_internal;
67
68 if (bcache->nentries <= index)
69 return -pte_internal;
70
71 /* We rely on guaranteed atomic operations as specified in section 8.1.1
72 * in Volume 3A of the Intel(R) Software Developer's Manual at
73 * http://www.intel.com/sdm.
74 */
75 bcache->entry[(uint32_t) index] = bce;
76
77 return 0;
78 }
79
pt_bcache_lookup(struct pt_bcache_entry * bce,const struct pt_block_cache * bcache,uint64_t index)80 int pt_bcache_lookup(struct pt_bcache_entry *bce,
81 const struct pt_block_cache *bcache, uint64_t index)
82 {
83 if (!bce || !bcache)
84 return -pte_internal;
85
86 if (bcache->nentries <= index)
87 return -pte_internal;
88
89 /* We rely on guaranteed atomic operations as specified in section 8.1.1
90 * in Volume 3A of the Intel(R) Software Developer's Manual at
91 * http://www.intel.com/sdm.
92 */
93 *bce = bcache->entry[(uint32_t) index];
94
95 return 0;
96 }
97