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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 <[email protected]>
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 */
25struct 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 */
50static char lgr_page[PAGE_SIZE] __aligned(PAGE_SIZE);
51static struct lgr_info lgr_info_last;
52static struct lgr_info lgr_info_cur;
53static struct debug_info *lgr_dbf;
54
55/*
56 * Copy buffer and then convert it to ASCII
57 */
58static 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 */
67static 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(lgr_info->manufacturer, si->manufacturer,
74 sizeof(si->manufacturer));
75 cpascii(lgr_info->type, si->type, sizeof(si->type));
76 cpascii(lgr_info->model, si->model, sizeof(si->model));
77 cpascii(lgr_info->sequence, si->sequence, sizeof(si->sequence));
78 cpascii(lgr_info->plant, si->plant, sizeof(si->plant));
79}
80
81/*
82 * Fill LGR info with 2.2.2 stsi data
83 */
84static 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(lgr_info->name, si->name, 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 */
97static 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(lgr_info->vm[i].name, si->vm[i].name,
106 sizeof(si->vm[i].name));
107 cpascii(lgr_info->vm[i].cpi, si->vm[i].cpi,
108 sizeof(si->vm[i].cpi));
109 }
110 lgr_info->vm_count = si->count;
111}
112
113/*
114 * Fill LGR info with current data
115 */
116static 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 */
135void 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_cur);
143 if (memcmp(&lgr_info_last, &lgr_info_cur, 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(&lgr_info_lock, flags);
148}
149EXPORT_SYMBOL_GPL(lgr_info_log);
150
151static void lgr_timer_set(void);
152
153/*
154 * LGR timer callback
155 */
156static void lgr_timer_fn(struct timer_list *unused)
157{
158 lgr_info_log();
159 lgr_timer_set();
160}
161
162static struct timer_list lgr_timer;
163
164/*
165 * Setup next LGR timer
166 */
167static void lgr_timer_set(void)
168{
169 mod_timer(&lgr_timer, jiffies + secs_to_jiffies(LGR_TIMER_INTERVAL_SECS));
170}
171
172/*
173 * Initialize LGR: Add s390dbf, write initial lgr_info and setup timer
174 */
175static 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 timer_setup(&lgr_timer, lgr_timer_fn, TIMER_DEFERRABLE);
184 lgr_timer_set();
185 return 0;
186}
187device_initcall(lgr_init);