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  * Copy buffer and then convert it to ASCII
  55  */
  56 static 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  */
  65 static 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  */
  82 static 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  */
  96 static 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  */
 115 static 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  */
 134 void 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 }
 148 EXPORT_SYMBOL_GPL(lgr_info_log);
 149
 150 static void lgr_timer_set(void);
 151
 152 /*
 153  * LGR timer callback
 154  */
 155 static void lgr_timer_fn(unsigned long ignored)
 156 {
 157         lgr_info_log();
 158         lgr_timer_set();
 159 }
 160
 161 static struct timer_list lgr_timer =
 162         TIMER_DEFERRED_INITIALIZER(lgr_timer_fn, 0, 0);
 163
 164 /*
 165  * Setup next LGR timer
 166  */
 167 static 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  */
 175 static 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 }
 186 module_init(lgr_init);