s390/kernel/lgr.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Linux Guest Relocation (LGR) detection
0004  *
0005  * Copyright IBM Corp. 2012
0006  * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
0007  */
0008
0009 #include <linux/init.h>
0010 #include <linux/export.h>
0011 #include <linux/timer.h>
0012 #include <linux/slab.h>
0013 #include <asm/facility.h>
0014 #include <asm/sysinfo.h>
0015 #include <asm/ebcdic.h>
0016 #include <asm/debug.h>
0017 #include <asm/ipl.h>
0018
0019 #define LGR_TIMER_INTERVAL_SECS (30 * 60)
0020 #define VM_LEVEL_MAX 2 /* Maximum is 8, but we only record two levels */
0021
0022 /*
0023  * LGR info: Contains stfle and stsi data
0024  */
0025 struct lgr_info {
0026     /* Bit field with facility information: 4 DWORDs are stored */
0027     u64 stfle_fac_list[4];
0028     /* Level of system (1 = CEC, 2 = LPAR, 3 = z/VM */
0029     u32 level;
0030     /* Level 1: CEC info (stsi 1.1.1) */
0031     char manufacturer[16];
0032     char type[4];
0033     char sequence[16];
0034     char plant[4];
0035     char model[16];
0036     /* Level 2: LPAR info (stsi 2.2.2) */
0037     u16 lpar_number;
0038     char name[8];
0039     /* Level 3: VM info (stsi 3.2.2) */
0040     u8 vm_count;
0041     struct {
0042         char name[8];
0043         char cpi[16];
0044     } vm[VM_LEVEL_MAX];
0045 } __packed __aligned(8);
0046
0047 /*
0048  * LGR globals
0049  */
0050 static char lgr_page[PAGE_SIZE] __aligned(PAGE_SIZE);
0051 static struct lgr_info lgr_info_last;
0052 static struct lgr_info lgr_info_cur;
0053 static struct debug_info *lgr_dbf;
0054
0055 /*
0056  * Copy buffer and then convert it to ASCII
0057  */
0058 static void cpascii(char *dst, char *src, int size)
0059 {
0060     memcpy(dst, src, size);
0061     EBCASC(dst, size);
0062 }
0063
0064 /*
0065  * Fill LGR info with 1.1.1 stsi data
0066  */
0067 static void lgr_stsi_1_1_1(struct lgr_info *lgr_info)
0068 {
0069     struct sysinfo_1_1_1 *si = (void *) lgr_page;
0070
0071     if (stsi(si, 1, 1, 1))
0072         return;
0073     cpascii(lgr_info->manufacturer, si->manufacturer,
0074         sizeof(si->manufacturer));
0075     cpascii(lgr_info->type, si->type, sizeof(si->type));
0076     cpascii(lgr_info->model, si->model, sizeof(si->model));
0077     cpascii(lgr_info->sequence, si->sequence, sizeof(si->sequence));
0078     cpascii(lgr_info->plant, si->plant, sizeof(si->plant));
0079 }
0080
0081 /*
0082  * Fill LGR info with 2.2.2 stsi data
0083  */
0084 static void lgr_stsi_2_2_2(struct lgr_info *lgr_info)
0085 {
0086     struct sysinfo_2_2_2 *si = (void *) lgr_page;
0087
0088     if (stsi(si, 2, 2, 2))
0089         return;
0090     cpascii(lgr_info->name, si->name, sizeof(si->name));
0091     lgr_info->lpar_number = si->lpar_number;
0092 }
0093
0094 /*
0095  * Fill LGR info with 3.2.2 stsi data
0096  */
0097 static void lgr_stsi_3_2_2(struct lgr_info *lgr_info)
0098 {
0099     struct sysinfo_3_2_2 *si = (void *) lgr_page;
0100     int i;
0101
0102     if (stsi(si, 3, 2, 2))
0103         return;
0104     for (i = 0; i < min_t(u8, si->count, VM_LEVEL_MAX); i++) {
0105         cpascii(lgr_info->vm[i].name, si->vm[i].name,
0106             sizeof(si->vm[i].name));
0107         cpascii(lgr_info->vm[i].cpi, si->vm[i].cpi,
0108             sizeof(si->vm[i].cpi));
0109     }
0110     lgr_info->vm_count = si->count;
0111 }
0112
0113 /*
0114  * Fill LGR info with current data
0115  */
0116 static void lgr_info_get(struct lgr_info *lgr_info)
0117 {
0118     int level;
0119
0120     memset(lgr_info, 0, sizeof(*lgr_info));
0121     stfle(lgr_info->stfle_fac_list, ARRAY_SIZE(lgr_info->stfle_fac_list));
0122     level = stsi(NULL, 0, 0, 0);
0123     lgr_info->level = level;
0124     if (level >= 1)
0125         lgr_stsi_1_1_1(lgr_info);
0126     if (level >= 2)
0127         lgr_stsi_2_2_2(lgr_info);
0128     if (level >= 3)
0129         lgr_stsi_3_2_2(lgr_info);
0130 }
0131
0132 /*
0133  * Check if LGR info has changed and if yes log new LGR info to s390dbf
0134  */
0135 void lgr_info_log(void)
0136 {
0137     static DEFINE_SPINLOCK(lgr_info_lock);
0138     unsigned long flags;
0139
0140     if (!spin_trylock_irqsave(&lgr_info_lock, flags))
0141         return;
0142     lgr_info_get(&lgr_info_cur);
0143     if (memcmp(&lgr_info_last, &lgr_info_cur, sizeof(lgr_info_cur)) != 0) {
0144         debug_event(lgr_dbf, 1, &lgr_info_cur, sizeof(lgr_info_cur));
0145         lgr_info_last = lgr_info_cur;
0146     }
0147     spin_unlock_irqrestore(&lgr_info_lock, flags);
0148 }
0149 EXPORT_SYMBOL_GPL(lgr_info_log);
0150
0151 static void lgr_timer_set(void);
0152
0153 /*
0154  * LGR timer callback
0155  */
0156 static void lgr_timer_fn(struct timer_list *unused)
0157 {
0158     lgr_info_log();
0159     lgr_timer_set();
0160 }
0161
0162 static struct timer_list lgr_timer;
0163
0164 /*
0165  * Setup next LGR timer
0166  */
0167 static void lgr_timer_set(void)
0168 {
0169     mod_timer(&lgr_timer, jiffies + msecs_to_jiffies(LGR_TIMER_INTERVAL_SECS * MSEC_PER_SEC));
0170 }
0171
0172 /*
0173  * Initialize LGR: Add s390dbf, write initial lgr_info and setup timer
0174  */
0175 static int __init lgr_init(void)
0176 {
0177     lgr_dbf = debug_register("lgr", 1, 1, sizeof(struct lgr_info));
0178     if (!lgr_dbf)
0179         return -ENOMEM;
0180     debug_register_view(lgr_dbf, &debug_hex_ascii_view);
0181     lgr_info_get(&lgr_info_last);
0182     debug_event(lgr_dbf, 1, &lgr_info_last, sizeof(lgr_info_last));
0183     timer_setup(&lgr_timer, lgr_timer_fn, TIMER_DEFERRABLE);
0184     lgr_timer_set();
0185     return 0;
0186 }
0187 device_initcall(lgr_init);