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/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 */
  23struct 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 */
  48static void *lgr_page;
  49static struct lgr_info lgr_info_last;
  50static struct lgr_info lgr_info_cur;
  51static struct debug_info *lgr_dbf;
  52
  53/*
  54 * Return number of valid stsi levels
  55 */
  56static 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 */
  66static 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 */
  75static void lgr_stsi_1_1_1(struct lgr_info *lgr_info)
  76{
  77        struct sysinfo_1_1_1 *si = 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 */
  92static void lgr_stsi_2_2_2(struct lgr_info *lgr_info)
  93{
  94        struct sysinfo_2_2_2 *si = 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 */
 106static void lgr_stsi_3_2_2(struct lgr_info *lgr_info)
 107{
 108        struct sysinfo_3_2_2 *si = 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 */
 125static 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 */
 143void 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}
 157EXPORT_SYMBOL_GPL(lgr_info_log);
 158
 159static void lgr_timer_set(void);
 160
 161/*
 162 * LGR timer callback
 163 */
 164static void lgr_timer_fn(unsigned long ignored)
 165{
 166        lgr_info_log();
 167        lgr_timer_set();
 168}
 169
 170static struct timer_list lgr_timer =
 171        TIMER_DEFERRED_INITIALIZER(lgr_timer_fn, 0, 0);
 172
 173/*
 174 * Setup next LGR timer
 175 */
 176static 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 */
 184static int __init lgr_init(void)
 185{
 186        lgr_page = (void *) __get_free_pages(GFP_KERNEL, 0);
 187        if (!lgr_page)
 188                return -ENOMEM;
 189        lgr_dbf = debug_register("lgr", 1, 1, sizeof(struct lgr_info));
 190        if (!lgr_dbf) {
 191                free_page((unsigned long) lgr_page);
 192                return -ENOMEM;
 193        }
 194        debug_register_view(lgr_dbf, &debug_hex_ascii_view);
 195        lgr_info_get(&lgr_info_last);
 196        debug_event(lgr_dbf, 1, &lgr_info_last, sizeof(lgr_info_last));
 197        lgr_timer_set();
 198        return 0;
 199}
 200module_init(lgr_init);
 201