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 */
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 */
48static char lgr_page[PAGE_SIZE] __aligned(PAGE_SIZE);
49static struct lgr_info lgr_info_last;
50static struct lgr_info lgr_info_cur;
51static struct debug_info *lgr_dbf;
52
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{
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 */
82static 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 */
96static 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 */
115static 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 */
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{
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}
186module_init(lgr_init);
187