xref: /openbmc/linux/arch/s390/kernel/lgr.c (revision bc5aa3a0)
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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