1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Linux Guest Relocation (LGR) detection |
4 | * |
5 | * Copyright IBM Corp. 2012 |
6 | * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com> |
7 | */ |
8 | |
9 | #include <linux/init.h> |
10 | #include <linux/export.h> |
11 | #include <linux/timer.h> |
12 | #include <linux/slab.h> |
13 | #include <asm/facility.h> |
14 | #include <asm/sysinfo.h> |
15 | #include <asm/ebcdic.h> |
16 | #include <asm/debug.h> |
17 | #include <asm/ipl.h> |
18 | |
19 | #define LGR_TIMER_INTERVAL_SECS (30 * 60) |
20 | #define VM_LEVEL_MAX 2 /* Maximum is 8, but we only record two levels */ |
21 | |
22 | /* |
23 | * LGR info: Contains stfle and stsi data |
24 | */ |
25 | struct lgr_info { |
26 | /* Bit field with facility information: 4 DWORDs are stored */ |
27 | u64 stfle_fac_list[4]; |
28 | /* Level of system (1 = CEC, 2 = LPAR, 3 = z/VM */ |
29 | u32 level; |
30 | /* Level 1: CEC info (stsi 1.1.1) */ |
31 | char manufacturer[16]; |
32 | char type[4]; |
33 | char sequence[16]; |
34 | char plant[4]; |
35 | char model[16]; |
36 | /* Level 2: LPAR info (stsi 2.2.2) */ |
37 | u16 lpar_number; |
38 | char name[8]; |
39 | /* Level 3: VM info (stsi 3.2.2) */ |
40 | u8 vm_count; |
41 | struct { |
42 | char name[8]; |
43 | char cpi[16]; |
44 | } vm[VM_LEVEL_MAX]; |
45 | } __packed __aligned(8); |
46 | |
47 | /* |
48 | * LGR globals |
49 | */ |
50 | static char lgr_page[PAGE_SIZE] __aligned(PAGE_SIZE); |
51 | static struct lgr_info lgr_info_last; |
52 | static struct lgr_info lgr_info_cur; |
53 | static struct debug_info *lgr_dbf; |
54 | |
55 | /* |
56 | * Copy buffer and then convert it to ASCII |
57 | */ |
58 | static void cpascii(char *dst, char *src, int size) |
59 | { |
60 | memcpy(dst, src, size); |
61 | EBCASC(dst, size); |
62 | } |
63 | |
64 | /* |
65 | * Fill LGR info with 1.1.1 stsi data |
66 | */ |
67 | static void lgr_stsi_1_1_1(struct lgr_info *lgr_info) |
68 | { |
69 | struct sysinfo_1_1_1 *si = (void *) lgr_page; |
70 | |
71 | if (stsi(si, 1, 1, 1)) |
72 | return; |
73 | cpascii(dst: lgr_info->manufacturer, src: si->manufacturer, |
74 | size: sizeof(si->manufacturer)); |
75 | cpascii(dst: lgr_info->type, src: si->type, size: sizeof(si->type)); |
76 | cpascii(dst: lgr_info->model, src: si->model, size: sizeof(si->model)); |
77 | cpascii(dst: lgr_info->sequence, src: si->sequence, size: sizeof(si->sequence)); |
78 | cpascii(dst: lgr_info->plant, src: si->plant, size: sizeof(si->plant)); |
79 | } |
80 | |
81 | /* |
82 | * Fill LGR info with 2.2.2 stsi data |
83 | */ |
84 | static void lgr_stsi_2_2_2(struct lgr_info *lgr_info) |
85 | { |
86 | struct sysinfo_2_2_2 *si = (void *) lgr_page; |
87 | |
88 | if (stsi(si, 2, 2, 2)) |
89 | return; |
90 | cpascii(dst: lgr_info->name, src: si->name, size: sizeof(si->name)); |
91 | lgr_info->lpar_number = si->lpar_number; |
92 | } |
93 | |
94 | /* |
95 | * Fill LGR info with 3.2.2 stsi data |
96 | */ |
97 | static void lgr_stsi_3_2_2(struct lgr_info *lgr_info) |
98 | { |
99 | struct sysinfo_3_2_2 *si = (void *) lgr_page; |
100 | int i; |
101 | |
102 | if (stsi(si, 3, 2, 2)) |
103 | return; |
104 | for (i = 0; i < min_t(u8, si->count, VM_LEVEL_MAX); i++) { |
105 | cpascii(dst: lgr_info->vm[i].name, src: si->vm[i].name, |
106 | size: sizeof(si->vm[i].name)); |
107 | cpascii(dst: lgr_info->vm[i].cpi, src: si->vm[i].cpi, |
108 | size: sizeof(si->vm[i].cpi)); |
109 | } |
110 | lgr_info->vm_count = si->count; |
111 | } |
112 | |
113 | /* |
114 | * Fill LGR info with current data |
115 | */ |
116 | static void lgr_info_get(struct lgr_info *lgr_info) |
117 | { |
118 | int level; |
119 | |
120 | memset(lgr_info, 0, sizeof(*lgr_info)); |
121 | stfle(lgr_info->stfle_fac_list, ARRAY_SIZE(lgr_info->stfle_fac_list)); |
122 | level = stsi(NULL, 0, 0, 0); |
123 | lgr_info->level = level; |
124 | if (level >= 1) |
125 | lgr_stsi_1_1_1(lgr_info); |
126 | if (level >= 2) |
127 | lgr_stsi_2_2_2(lgr_info); |
128 | if (level >= 3) |
129 | lgr_stsi_3_2_2(lgr_info); |
130 | } |
131 | |
132 | /* |
133 | * Check if LGR info has changed and if yes log new LGR info to s390dbf |
134 | */ |
135 | void lgr_info_log(void) |
136 | { |
137 | static DEFINE_SPINLOCK(lgr_info_lock); |
138 | unsigned long flags; |
139 | |
140 | if (!spin_trylock_irqsave(&lgr_info_lock, flags)) |
141 | return; |
142 | lgr_info_get(lgr_info: &lgr_info_cur); |
143 | if (memcmp(p: &lgr_info_last, q: &lgr_info_cur, size: sizeof(lgr_info_cur)) != 0) { |
144 | debug_event(lgr_dbf, 1, &lgr_info_cur, sizeof(lgr_info_cur)); |
145 | lgr_info_last = lgr_info_cur; |
146 | } |
147 | spin_unlock_irqrestore(lock: &lgr_info_lock, flags); |
148 | } |
149 | EXPORT_SYMBOL_GPL(lgr_info_log); |
150 | |
151 | static void lgr_timer_set(void); |
152 | |
153 | /* |
154 | * LGR timer callback |
155 | */ |
156 | static void lgr_timer_fn(struct timer_list *unused) |
157 | { |
158 | lgr_info_log(); |
159 | lgr_timer_set(); |
160 | } |
161 | |
162 | static struct timer_list lgr_timer; |
163 | |
164 | /* |
165 | * Setup next LGR timer |
166 | */ |
167 | static void lgr_timer_set(void) |
168 | { |
169 | mod_timer(timer: &lgr_timer, expires: jiffies + msecs_to_jiffies(LGR_TIMER_INTERVAL_SECS * MSEC_PER_SEC)); |
170 | } |
171 | |
172 | /* |
173 | * Initialize LGR: Add s390dbf, write initial lgr_info and setup timer |
174 | */ |
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: &lgr_info_last); |
182 | debug_event(lgr_dbf, 1, &lgr_info_last, sizeof(lgr_info_last)); |
183 | timer_setup(&lgr_timer, lgr_timer_fn, TIMER_DEFERRABLE); |
184 | lgr_timer_set(); |
185 | return 0; |
186 | } |
187 | device_initcall(lgr_init); |
188 | |