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/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  * Return number of valid stsi levels
  55  */
  56 static inline int stsi_0(void)
  57 {
  58         int rc = stsi(NULL, 0, 0, 0);
  59
  60         return rc == -ENOSYS ? rc : (((unsigned int) rc) >> 28);
  61 }
  62
  63 /*
  64  * Copy buffer and then convert it to ASCII
  65  */
  66 static void cpascii(char *dst, char *src, int size)
  67 {
  68         memcpy(dst, src, size);
  69         EBCASC(dst, size);
  70 }
  71
  72 /*
  73  * Fill LGR info with 1.1.1 stsi data
  74  */
  75 static void lgr_stsi_1_1_1(struct lgr_info *lgr_info)
  76 {
  77         struct sysinfo_1_1_1 *si = (void *) lgr_page;
  78
  79         if (stsi(si, 1, 1, 1) == -ENOSYS)
  80                 return;
  81         cpascii(lgr_info->manufacturer, si->manufacturer,
  82                 sizeof(si->manufacturer));
  83         cpascii(lgr_info->type, si->type, sizeof(si->type));
  84         cpascii(lgr_info->model, si->model, sizeof(si->model));
  85         cpascii(lgr_info->sequence, si->sequence, sizeof(si->sequence));
  86         cpascii(lgr_info->plant, si->plant, sizeof(si->plant));
  87 }
  88
  89 /*
  90  * Fill LGR info with 2.2.2 stsi data
  91  */
  92 static void lgr_stsi_2_2_2(struct lgr_info *lgr_info)
  93 {
  94         struct sysinfo_2_2_2 *si = (void *) lgr_page;
  95
  96         if (stsi(si, 2, 2, 2) == -ENOSYS)
  97                 return;
  98         cpascii(lgr_info->name, si->name, sizeof(si->name));
  99         memcpy(&lgr_info->lpar_number, &si->lpar_number,
 100                sizeof(lgr_info->lpar_number));
 101 }
 102
 103 /*
 104  * Fill LGR info with 3.2.2 stsi data
 105  */
 106 static void lgr_stsi_3_2_2(struct lgr_info *lgr_info)
 107 {
 108         struct sysinfo_3_2_2 *si = (void *) lgr_page;
 109         int i;
 110
 111         if (stsi(si, 3, 2, 2) == -ENOSYS)
 112                 return;
 113         for (i = 0; i < min_t(u8, si->count, VM_LEVEL_MAX); i++) {
 114                 cpascii(lgr_info->vm[i].name, si->vm[i].name,
 115                         sizeof(si->vm[i].name));
 116                 cpascii(lgr_info->vm[i].cpi, si->vm[i].cpi,
 117                         sizeof(si->vm[i].cpi));
 118         }
 119         lgr_info->vm_count = si->count;
 120 }
 121
 122 /*
 123  * Fill LGR info with current data
 124  */
 125 static void lgr_info_get(struct lgr_info *lgr_info)
 126 {
 127         memset(lgr_info, 0, sizeof(*lgr_info));
 128         stfle(lgr_info->stfle_fac_list, ARRAY_SIZE(lgr_info->stfle_fac_list));
 129         lgr_info->level = stsi_0();
 130         if (lgr_info->level == -ENOSYS)
 131                 return;
 132         if (lgr_info->level >= 1)
 133                 lgr_stsi_1_1_1(lgr_info);
 134         if (lgr_info->level >= 2)
 135                 lgr_stsi_2_2_2(lgr_info);
 136         if (lgr_info->level >= 3)
 137                 lgr_stsi_3_2_2(lgr_info);
 138 }
 139
 140 /*
 141  * Check if LGR info has changed and if yes log new LGR info to s390dbf
 142  */
 143 void lgr_info_log(void)
 144 {
 145         static DEFINE_SPINLOCK(lgr_info_lock);
 146         unsigned long flags;
 147
 148         if (!spin_trylock_irqsave(&lgr_info_lock, flags))
 149                 return;
 150         lgr_info_get(&lgr_info_cur);
 151         if (memcmp(&lgr_info_last, &lgr_info_cur, sizeof(lgr_info_cur)) != 0) {
 152                 debug_event(lgr_dbf, 1, &lgr_info_cur, sizeof(lgr_info_cur));
 153                 lgr_info_last = lgr_info_cur;
 154         }
 155         spin_unlock_irqrestore(&lgr_info_lock, flags);
 156 }
 157 EXPORT_SYMBOL_GPL(lgr_info_log);
 158
 159 static void lgr_timer_set(void);
 160
 161 /*
 162  * LGR timer callback
 163  */
 164 static void lgr_timer_fn(unsigned long ignored)
 165 {
 166         lgr_info_log();
 167         lgr_timer_set();
 168 }
 169
 170 static struct timer_list lgr_timer =
 171         TIMER_DEFERRED_INITIALIZER(lgr_timer_fn, 0, 0);
 172
 173 /*
 174  * Setup next LGR timer
 175  */
 176 static void lgr_timer_set(void)
 177 {
 178         mod_timer(&lgr_timer, jiffies + LGR_TIMER_INTERVAL_SECS * HZ);
 179 }
 180
 181 /*
 182  * Initialize LGR: Add s390dbf, write initial lgr_info and setup timer
 183  */
 184 static int __init lgr_init(void)
 185 {
 186         lgr_dbf = debug_register("lgr", 1, 1, sizeof(struct lgr_info));
 187         if (!lgr_dbf)
 188                 return -ENOMEM;
 189         debug_register_view(lgr_dbf, &debug_hex_ascii_view);
 190         lgr_info_get(&lgr_info_last);
 191         debug_event(lgr_dbf, 1, &lgr_info_last, sizeof(lgr_info_last));
 192         lgr_timer_set();
 193         return 0;
 194 }
 195 module_init(lgr_init);