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(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 */ 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(lgr_info->name, si->name, sizeof(si->name)); 91 memcpy(&lgr_info->lpar_number, &si->lpar_number, 92 sizeof(lgr_info->lpar_number)); 93 } 94 95 /* 96 * Fill LGR info with 3.2.2 stsi data 97 */ 98 static void lgr_stsi_3_2_2(struct lgr_info *lgr_info) 99 { 100 struct sysinfo_3_2_2 *si = (void *) lgr_page; 101 int i; 102 103 if (stsi(si, 3, 2, 2)) 104 return; 105 for (i = 0; i < min_t(u8, si->count, VM_LEVEL_MAX); i++) { 106 cpascii(lgr_info->vm[i].name, si->vm[i].name, 107 sizeof(si->vm[i].name)); 108 cpascii(lgr_info->vm[i].cpi, si->vm[i].cpi, 109 sizeof(si->vm[i].cpi)); 110 } 111 lgr_info->vm_count = si->count; 112 } 113 114 /* 115 * Fill LGR info with current data 116 */ 117 static void lgr_info_get(struct lgr_info *lgr_info) 118 { 119 int level; 120 121 memset(lgr_info, 0, sizeof(*lgr_info)); 122 stfle(lgr_info->stfle_fac_list, ARRAY_SIZE(lgr_info->stfle_fac_list)); 123 level = stsi(NULL, 0, 0, 0); 124 lgr_info->level = level; 125 if (level >= 1) 126 lgr_stsi_1_1_1(lgr_info); 127 if (level >= 2) 128 lgr_stsi_2_2_2(lgr_info); 129 if (level >= 3) 130 lgr_stsi_3_2_2(lgr_info); 131 } 132 133 /* 134 * Check if LGR info has changed and if yes log new LGR info to s390dbf 135 */ 136 void lgr_info_log(void) 137 { 138 static DEFINE_SPINLOCK(lgr_info_lock); 139 unsigned long flags; 140 141 if (!spin_trylock_irqsave(&lgr_info_lock, flags)) 142 return; 143 lgr_info_get(&lgr_info_cur); 144 if (memcmp(&lgr_info_last, &lgr_info_cur, sizeof(lgr_info_cur)) != 0) { 145 debug_event(lgr_dbf, 1, &lgr_info_cur, sizeof(lgr_info_cur)); 146 lgr_info_last = lgr_info_cur; 147 } 148 spin_unlock_irqrestore(&lgr_info_lock, flags); 149 } 150 EXPORT_SYMBOL_GPL(lgr_info_log); 151 152 static void lgr_timer_set(void); 153 154 /* 155 * LGR timer callback 156 */ 157 static void lgr_timer_fn(struct timer_list *unused) 158 { 159 lgr_info_log(); 160 lgr_timer_set(); 161 } 162 163 static struct timer_list lgr_timer; 164 165 /* 166 * Setup next LGR timer 167 */ 168 static void lgr_timer_set(void) 169 { 170 mod_timer(&lgr_timer, jiffies + msecs_to_jiffies(LGR_TIMER_INTERVAL_SECS * MSEC_PER_SEC)); 171 } 172 173 /* 174 * Initialize LGR: Add s390dbf, write initial lgr_info and setup timer 175 */ 176 static int __init lgr_init(void) 177 { 178 lgr_dbf = debug_register("lgr", 1, 1, sizeof(struct lgr_info)); 179 if (!lgr_dbf) 180 return -ENOMEM; 181 debug_register_view(lgr_dbf, &debug_hex_ascii_view); 182 lgr_info_get(&lgr_info_last); 183 debug_event(lgr_dbf, 1, &lgr_info_last, sizeof(lgr_info_last)); 184 timer_setup(&lgr_timer, lgr_timer_fn, TIMER_DEFERRABLE); 185 lgr_timer_set(); 186 return 0; 187 } 188 device_initcall(lgr_init); 189