LXR linux/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 */
  24struct 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 */
  49static char lgr_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  50static struct lgr_info lgr_info_last;
  51static struct lgr_info lgr_info_cur;
  52static struct debug_info *lgr_dbf;
  53
  54/*
  55 * Copy buffer and then convert it to ASCII
  56 */
  57static 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 */
  66static 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 */
  83static 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 */
  97static 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 */
 116static 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 */
 135void 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}
 149EXPORT_SYMBOL_GPL(lgr_info_log);
 150
 151static void lgr_timer_set(void);
 152
 153/*
 154 * LGR timer callback
 155 */
 156static void lgr_timer_fn(unsigned long ignored)
 157{
 158        lgr_info_log();
 159        lgr_timer_set();
 160}
 161
 162static struct timer_list lgr_timer =
 163        TIMER_DEFERRED_INITIALIZER(lgr_timer_fn, 0, 0);
 164
 165/*
 166 * Setup next LGR timer
 167 */
 168static 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 */
 176static 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}
 187device_initcall(lgr_init);
 188