arch/s390/kernel/lgr.c

   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/init.h>
   9 #include <linux/export.h>
  10 #include <linux/timer.h>
  11 #include <linux/slab.h>
  12 #include <asm/facility.h>
  13 #include <asm/sysinfo.h>
  14 #include <asm/ebcdic.h>
  15 #include <asm/debug.h>
  16 #include <asm/ipl.h>
  17
  18 #define LGR_TIMER_INTERVAL_SECS (30 * 60)
  19 #define VM_LEVEL_MAX 2 /* Maximum is 8, but we only record two levels */
  20
  21 /*
  22  * LGR info: Contains stfle and stsi data
  23  */
  24 struct lgr_info {
  25         /* Bit field with facility information: 4 DWORDs are stored */
  26         u64 stfle_fac_list[4];
  27         /* Level of system (1 = CEC, 2 = LPAR, 3 = z/VM */
  28         u32 level;
  29         /* Level 1: CEC info (stsi 1.1.1) */
  30         char manufacturer[16];
  31         char type[4];
  32         char sequence[16];
  33         char plant[4];
  34         char model[16];
  35         /* Level 2: LPAR info (stsi 2.2.2) */
  36         u16 lpar_number;
  37         char name[8];
  38         /* Level 3: VM info (stsi 3.2.2) */
  39         u8 vm_count;
  40         struct {
  41                 char name[8];
  42                 char cpi[16];
  43         } vm[VM_LEVEL_MAX];
  44 } __packed __aligned(8);
  45
  46 /*
  47  * LGR globals
  48  */
  49 static char lgr_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  50 static struct lgr_info lgr_info_last;
  51 static struct lgr_info lgr_info_cur;
  52 static struct debug_info *lgr_dbf;
  53
  54 /*
  55  * Copy buffer and then convert it to ASCII
  56  */
  57 static void cpascii(char *dst, char *src, int size)
  58 {
  59         memcpy(dst, src, size);
  60         EBCASC(dst, size);
  61 }
  62
  63 /*
  64  * Fill LGR info with 1.1.1 stsi data
  65  */
  66 static void lgr_stsi_1_1_1(struct lgr_info *lgr_info)
  67 {
  68         struct sysinfo_1_1_1 *si = (void *) lgr_page;
  69
  70         if (stsi(si, 1, 1, 1))
  71                 return;
  72         cpascii(lgr_info->manufacturer, si->manufacturer,
  73                 sizeof(si->manufacturer));
  74         cpascii(lgr_info->type, si->type, sizeof(si->type));
  75         cpascii(lgr_info->model, si->model, sizeof(si->model));
  76         cpascii(lgr_info->sequence, si->sequence, sizeof(si->sequence));
  77         cpascii(lgr_info->plant, si->plant, sizeof(si->plant));
  78 }
  79
  80 /*
  81  * Fill LGR info with 2.2.2 stsi data
  82  */
  83 static void lgr_stsi_2_2_2(struct lgr_info *lgr_info)
  84 {
  85         struct sysinfo_2_2_2 *si = (void *) lgr_page;
  86
  87         if (stsi(si, 2, 2, 2))
  88                 return;
  89         cpascii(lgr_info->name, si->name, sizeof(si->name));
  90         memcpy(&lgr_info->lpar_number, &si->lpar_number,
  91                sizeof(lgr_info->lpar_number));
  92 }
  93
  94 /*
  95  * Fill LGR info with 3.2.2 stsi data
  96  */
  97 static 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  */
 116 static 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  */
 135 void 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 }
 149 EXPORT_SYMBOL_GPL(lgr_info_log);
 150
 151 static void lgr_timer_set(void);
 152
 153 /*
 154  * LGR timer callback
 155  */
 156 static void lgr_timer_fn(unsigned long ignored)
 157 {
 158         lgr_info_log();
 159         lgr_timer_set();
 160 }
 161
 162 static struct timer_list lgr_timer =
 163         TIMER_DEFERRED_INITIALIZER(lgr_timer_fn, 0, 0);
 164
 165 /*
 166  * Setup next LGR timer
 167  */
 168 static void lgr_timer_set(void)
 169 {
 170         mod_timer(&lgr_timer, jiffies + LGR_TIMER_INTERVAL_SECS * HZ);
 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         lgr_timer_set();
 185         return 0;
 186 }
 187 device_initcall(lgr_init);