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>
11 #include <asm/facility.h>
12 #include <asm/sysinfo.h>
13 #include <asm/ebcdic.h>
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 */
23 struct 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 */
48 static char lgr_page[PAGE_SIZE] __aligned(PAGE_SIZE);
49 static struct lgr_info lgr_info_last;
50 static struct lgr_info lgr_info_cur;
51 static struct debug_info *lgr_dbf;
52
53 /*
54 * Copy buffer and then convert it to ASCII
55 */
cpascii(char * dst,char * src,int size)56 static 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 */
lgr_stsi_1_1_1(struct lgr_info * lgr_info)65 static void lgr_stsi_1_1_1(struct lgr_info *lgr_info)
66 {
67 struct sysinfo_1_1_1 *si = (void *) lgr_page;
68
69 if (stsi(si, 1, 1, 1))
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 */
lgr_stsi_2_2_2(struct lgr_info * lgr_info)82 static void lgr_stsi_2_2_2(struct lgr_info *lgr_info)
83 {
84 struct sysinfo_2_2_2 *si = (void *) lgr_page;
85
86 if (stsi(si, 2, 2, 2))
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 */
lgr_stsi_3_2_2(struct lgr_info * lgr_info)96 static void lgr_stsi_3_2_2(struct lgr_info *lgr_info)
97 {
98 struct sysinfo_3_2_2 *si = (void *) lgr_page;
99 int i;
100
101 if (stsi(si, 3, 2, 2))
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 */
lgr_info_get(struct lgr_info * lgr_info)115 static void lgr_info_get(struct lgr_info *lgr_info)
116 {
117 int level;
118
119 memset(lgr_info, 0, sizeof(*lgr_info));
120 stfle(lgr_info->stfle_fac_list, ARRAY_SIZE(lgr_info->stfle_fac_list));
121 level = stsi(NULL, 0, 0, 0);
122 lgr_info->level = level;
123 if (level >= 1)
124 lgr_stsi_1_1_1(lgr_info);
125 if (level >= 2)
126 lgr_stsi_2_2_2(lgr_info);
127 if (level >= 3)
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 */
lgr_info_log(void)134 void 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 }
148 EXPORT_SYMBOL_GPL(lgr_info_log);
149
150 static void lgr_timer_set(void);
151
152 /*
153 * LGR timer callback
154 */
lgr_timer_fn(unsigned long ignored)155 static void lgr_timer_fn(unsigned long ignored)
156 {
157 lgr_info_log();
158 lgr_timer_set();
159 }
160
161 static struct timer_list lgr_timer =
162 TIMER_DEFERRED_INITIALIZER(lgr_timer_fn, 0, 0);
163
164 /*
165 * Setup next LGR timer
166 */
lgr_timer_set(void)167 static 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 */
lgr_init(void)175 static int __init lgr_init(void)
176 {
177 lgr_dbf = debug_register("lgr", 1, 1, sizeof(struct lgr_info));
178 if (!lgr_dbf)
179 return -ENOMEM;
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 }
186 module_init(lgr_init);
187