Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
[linux-2.6-block.git] / arch / s390 / kernel / lgr.c
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1/*
2 * Linux Guest Relocation (LGR) detection
3 *
4 * Copyright IBM Corp. 2012
5 * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
6 */
7
8#include <linux/module.h>
9#include <linux/timer.h>
10#include <linux/slab.h>
1e3cab2f 11#include <asm/facility.h>
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12#include <asm/sysinfo.h>
13#include <asm/ebcdic.h>
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14#include <asm/debug.h>
15#include <asm/ipl.h>
16
17#define LGR_TIMER_INTERVAL_SECS (30 * 60)
18#define VM_LEVEL_MAX 2 /* Maximum is 8, but we only record two levels */
19
20/*
21 * LGR info: Contains stfle and stsi data
22 */
23struct lgr_info {
24 /* Bit field with facility information: 4 DWORDs are stored */
25 u64 stfle_fac_list[4];
26 /* Level of system (1 = CEC, 2 = LPAR, 3 = z/VM */
27 u32 level;
28 /* Level 1: CEC info (stsi 1.1.1) */
29 char manufacturer[16];
30 char type[4];
31 char sequence[16];
32 char plant[4];
33 char model[16];
34 /* Level 2: LPAR info (stsi 2.2.2) */
35 u16 lpar_number;
36 char name[8];
37 /* Level 3: VM info (stsi 3.2.2) */
38 u8 vm_count;
39 struct {
40 char name[8];
41 char cpi[16];
42 } vm[VM_LEVEL_MAX];
43} __packed __aligned(8);
44
45/*
46 * LGR globals
47 */
2b754757 48static char lgr_page[PAGE_SIZE] __aligned(PAGE_SIZE);
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49static struct lgr_info lgr_info_last;
50static struct lgr_info lgr_info_cur;
51static struct debug_info *lgr_dbf;
52
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53/*
54 * Copy buffer and then convert it to ASCII
55 */
56static void cpascii(char *dst, char *src, int size)
57{
58 memcpy(dst, src, size);
59 EBCASC(dst, size);
60}
61
62/*
63 * Fill LGR info with 1.1.1 stsi data
64 */
65static void lgr_stsi_1_1_1(struct lgr_info *lgr_info)
66{
2b754757 67 struct sysinfo_1_1_1 *si = (void *) lgr_page;
3ab121ab 68
caf757c6 69 if (stsi(si, 1, 1, 1))
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70 return;
71 cpascii(lgr_info->manufacturer, si->manufacturer,
72 sizeof(si->manufacturer));
73 cpascii(lgr_info->type, si->type, sizeof(si->type));
74 cpascii(lgr_info->model, si->model, sizeof(si->model));
75 cpascii(lgr_info->sequence, si->sequence, sizeof(si->sequence));
76 cpascii(lgr_info->plant, si->plant, sizeof(si->plant));
77}
78
79/*
80 * Fill LGR info with 2.2.2 stsi data
81 */
82static void lgr_stsi_2_2_2(struct lgr_info *lgr_info)
83{
2b754757 84 struct sysinfo_2_2_2 *si = (void *) lgr_page;
3ab121ab 85
caf757c6 86 if (stsi(si, 2, 2, 2))
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87 return;
88 cpascii(lgr_info->name, si->name, sizeof(si->name));
89 memcpy(&lgr_info->lpar_number, &si->lpar_number,
90 sizeof(lgr_info->lpar_number));
91}
92
93/*
94 * Fill LGR info with 3.2.2 stsi data
95 */
96static void lgr_stsi_3_2_2(struct lgr_info *lgr_info)
97{
2b754757 98 struct sysinfo_3_2_2 *si = (void *) lgr_page;
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99 int i;
100
caf757c6 101 if (stsi(si, 3, 2, 2))
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102 return;
103 for (i = 0; i < min_t(u8, si->count, VM_LEVEL_MAX); i++) {
104 cpascii(lgr_info->vm[i].name, si->vm[i].name,
105 sizeof(si->vm[i].name));
106 cpascii(lgr_info->vm[i].cpi, si->vm[i].cpi,
107 sizeof(si->vm[i].cpi));
108 }
109 lgr_info->vm_count = si->count;
110}
111
112/*
113 * Fill LGR info with current data
114 */
115static void lgr_info_get(struct lgr_info *lgr_info)
116{
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117 int level;
118
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119 memset(lgr_info, 0, sizeof(*lgr_info));
120 stfle(lgr_info->stfle_fac_list, ARRAY_SIZE(lgr_info->stfle_fac_list));
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121 level = stsi(NULL, 0, 0, 0);
122 lgr_info->level = level;
123 if (level >= 1)
3ab121ab 124 lgr_stsi_1_1_1(lgr_info);
caf757c6 125 if (level >= 2)
3ab121ab 126 lgr_stsi_2_2_2(lgr_info);
caf757c6 127 if (level >= 3)
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128 lgr_stsi_3_2_2(lgr_info);
129}
130
131/*
132 * Check if LGR info has changed and if yes log new LGR info to s390dbf
133 */
134void lgr_info_log(void)
135{
136 static DEFINE_SPINLOCK(lgr_info_lock);
137 unsigned long flags;
138
139 if (!spin_trylock_irqsave(&lgr_info_lock, flags))
140 return;
141 lgr_info_get(&lgr_info_cur);
142 if (memcmp(&lgr_info_last, &lgr_info_cur, sizeof(lgr_info_cur)) != 0) {
143 debug_event(lgr_dbf, 1, &lgr_info_cur, sizeof(lgr_info_cur));
144 lgr_info_last = lgr_info_cur;
145 }
146 spin_unlock_irqrestore(&lgr_info_lock, flags);
147}
148EXPORT_SYMBOL_GPL(lgr_info_log);
149
150static void lgr_timer_set(void);
151
152/*
153 * LGR timer callback
154 */
155static void lgr_timer_fn(unsigned long ignored)
156{
157 lgr_info_log();
158 lgr_timer_set();
159}
160
161static struct timer_list lgr_timer =
162 TIMER_DEFERRED_INITIALIZER(lgr_timer_fn, 0, 0);
163
164/*
165 * Setup next LGR timer
166 */
167static void lgr_timer_set(void)
168{
169 mod_timer(&lgr_timer, jiffies + LGR_TIMER_INTERVAL_SECS * HZ);
170}
171
172/*
173 * Initialize LGR: Add s390dbf, write initial lgr_info and setup timer
174 */
175static int __init lgr_init(void)
176{
3ab121ab 177 lgr_dbf = debug_register("lgr", 1, 1, sizeof(struct lgr_info));
2b754757 178 if (!lgr_dbf)
3ab121ab 179 return -ENOMEM;
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180 debug_register_view(lgr_dbf, &debug_hex_ascii_view);
181 lgr_info_get(&lgr_info_last);
182 debug_event(lgr_dbf, 1, &lgr_info_last, sizeof(lgr_info_last));
183 lgr_timer_set();
184 return 0;
185}
186module_init(lgr_init);