1 /*
2 * Copyright (c) 2013 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28 #include <mach/mach_types.h>
29 #include <mach/host_info.h>
30 #include <kern/locks.h>
31 #include <kern/ecc.h>
32 #include <kern/spl.h>
33 #include <pexpert/pexpert.h>
34 #include <libkern/OSAtomic.h>
35
36 /*
37 * ECC data. Not really KPCs, but this still seems like the
38 * best home for this code.
39 *
40 * Circular buffer of events. When we fill up, drop data.
41 */
42 #define ECC_EVENT_BUFFER_COUNT 5
43 struct ecc_event ecc_data[ECC_EVENT_BUFFER_COUNT];
44 static uint32_t ecc_data_next_read;
45 static uint32_t ecc_data_next_write;
46 static boolean_t ecc_data_empty = TRUE; // next read == next write : empty or full?
47 static LCK_GRP_DECLARE(ecc_data_lock_group, "ecc-data");
48 static LCK_SPIN_DECLARE(ecc_data_lock, &ecc_data_lock_group);
49 static uint32_t ecc_correction_count;
50
51 uint32_t
ecc_log_get_correction_count()52 ecc_log_get_correction_count()
53 {
54 return ecc_correction_count;
55 }
56
57 kern_return_t
ecc_log_record_event(const struct ecc_event * ev)58 ecc_log_record_event(const struct ecc_event *ev)
59 {
60 spl_t x;
61
62 if (ev->count > ECC_EVENT_INFO_DATA_ENTRIES) {
63 panic("Count of %u on ecc event is too large.", (unsigned)ev->count);
64 }
65
66 x = splhigh();
67 lck_spin_lock(&ecc_data_lock);
68
69 ecc_correction_count++;
70
71 if (ecc_data_next_read == ecc_data_next_write && !ecc_data_empty) {
72 lck_spin_unlock(&ecc_data_lock);
73 splx(x);
74 return KERN_FAILURE;
75 }
76
77 bcopy(ev, &ecc_data[ecc_data_next_write], sizeof(*ev));
78 ecc_data_next_write++;
79 ecc_data_next_write %= ECC_EVENT_BUFFER_COUNT;
80 ecc_data_empty = FALSE;
81
82 lck_spin_unlock(&ecc_data_lock);
83 splx(x);
84
85 return KERN_SUCCESS;
86 }
87
88
89 kern_return_t
ecc_log_get_next_event(struct ecc_event * ev)90 ecc_log_get_next_event(struct ecc_event *ev)
91 {
92 spl_t x;
93
94 x = splhigh();
95 lck_spin_lock(&ecc_data_lock);
96
97 if (ecc_data_empty) {
98 assert(ecc_data_next_write == ecc_data_next_read);
99
100 lck_spin_unlock(&ecc_data_lock);
101 splx(x);
102 return KERN_FAILURE;
103 }
104
105 bcopy(&ecc_data[ecc_data_next_read], ev, sizeof(*ev));
106 ecc_data_next_read++;
107 ecc_data_next_read %= ECC_EVENT_BUFFER_COUNT;
108
109 if (ecc_data_next_read == ecc_data_next_write) {
110 ecc_data_empty = TRUE;
111 }
112
113 lck_spin_unlock(&ecc_data_lock);
114 splx(x);
115
116 return KERN_SUCCESS;
117 }
118