1 files changed, 200 insertions, 0 deletions

diff --git a/arch/s390/kernel/lgr.c b/arch/s390/kernel/lgr.c
new file mode 100644
index 000000000000..8431b92ca3ae
--- /dev/null
+++ b/arch/s390/kernel/lgr.c
@@ -0,0 +1,200 @@
+/*
+ * Linux Guest Relocation (LGR) detection
+ *
+ * Copyright IBM Corp. 2012
+ * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
+ */
+
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/slab.h>
+#include <asm/sysinfo.h>
+#include <asm/ebcdic.h>
+#include <asm/system.h>
+#include <asm/debug.h>
+#include <asm/ipl.h>
+
+#define LGR_TIMER_INTERVAL_SECS (30 * 60)
+#define VM_LEVEL_MAX 2 /* Maximum is 8, but we only record two levels */
+
+/*
+ * LGR info: Contains stfle and stsi data
+ */
+struct lgr_info {
+        /* Bit field with facility information: 4 DWORDs are stored */
+        u64 stfle_fac_list[4];
+        /* Level of system (1 = CEC, 2 = LPAR, 3 = z/VM */
+        u32 level;
+        /* Level 1: CEC info (stsi 1.1.1) */
+        char manufacturer[16];
+        char type[4];
+        char sequence[16];
+        char plant[4];
+        char model[16];
+        /* Level 2: LPAR info (stsi 2.2.2) */
+        u16 lpar_number;
+        char name[8];
+        /* Level 3: VM info (stsi 3.2.2) */
+        u8 vm_count;
+        struct {
+                char name[8];
+                char cpi[16];
+        } vm[VM_LEVEL_MAX];
+} __packed __aligned(8);
+
+/*
+ * LGR globals
+ */
+static void *lgr_page;
+static struct lgr_info lgr_info_last;
+static struct lgr_info lgr_info_cur;
+static struct debug_info *lgr_dbf;
+
+/*
+ * Return number of valid stsi levels
+ */
+static inline int stsi_0(void)
+{
+        int rc = stsi(NULL, 0, 0, 0);
+
+        return rc == -ENOSYS ? rc : (((unsigned int) rc) >> 28);
+}
+
+/*
+ * Copy buffer and then convert it to ASCII
+ */
+static void cpascii(char *dst, char *src, int size)
+{
+        memcpy(dst, src, size);
+        EBCASC(dst, size);
+}
+
+/*
+ * Fill LGR info with 1.1.1 stsi data
+ */
+static void lgr_stsi_1_1_1(struct lgr_info *lgr_info)
+{
+        struct sysinfo_1_1_1 *si = lgr_page;
+
+        if (stsi(si, 1, 1, 1) == -ENOSYS)
+                return;
+        cpascii(lgr_info->manufacturer, si->manufacturer,
+                sizeof(si->manufacturer));
+        cpascii(lgr_info->type, si->type, sizeof(si->type));
+        cpascii(lgr_info->model, si->model, sizeof(si->model));
+        cpascii(lgr_info->sequence, si->sequence, sizeof(si->sequence));
+        cpascii(lgr_info->plant, si->plant, sizeof(si->plant));
+}
+
+/*
+ * Fill LGR info with 2.2.2 stsi data
+ */
+static void lgr_stsi_2_2_2(struct lgr_info *lgr_info)
+{
+        struct sysinfo_2_2_2 *si = lgr_page;
+
+        if (stsi(si, 2, 2, 2) == -ENOSYS)
+                return;
+        cpascii(lgr_info->name, si->name, sizeof(si->name));
+        memcpy(&lgr_info->lpar_number, &si->lpar_number,
+               sizeof(lgr_info->lpar_number));
+}
+
+/*
+ * Fill LGR info with 3.2.2 stsi data
+ */
+static void lgr_stsi_3_2_2(struct lgr_info *lgr_info)
+{
+        struct sysinfo_3_2_2 *si = lgr_page;
+        int i;
+
+        if (stsi(si, 3, 2, 2) == -ENOSYS)
+                return;
+        for (i = 0; i < min_t(u8, si->count, VM_LEVEL_MAX); i++) {
+                cpascii(lgr_info->vm[i].name, si->vm[i].name,
+                        sizeof(si->vm[i].name));
+                cpascii(lgr_info->vm[i].cpi, si->vm[i].cpi,
+                        sizeof(si->vm[i].cpi));
+        }
+        lgr_info->vm_count = si->count;
+}
+
+/*
+ * Fill LGR info with current data
+ */
+static void lgr_info_get(struct lgr_info *lgr_info)
+{
+        memset(lgr_info, 0, sizeof(*lgr_info));
+        stfle(lgr_info->stfle_fac_list, ARRAY_SIZE(lgr_info->stfle_fac_list));
+        lgr_info->level = stsi_0();
+        if (lgr_info->level == -ENOSYS)
+                return;
+        if (lgr_info->level >= 1)
+                lgr_stsi_1_1_1(lgr_info);
+        if (lgr_info->level >= 2)
+                lgr_stsi_2_2_2(lgr_info);
+        if (lgr_info->level >= 3)
+                lgr_stsi_3_2_2(lgr_info);
+}
+
+/*
+ * Check if LGR info has changed and if yes log new LGR info to s390dbf
+ */
+void lgr_info_log(void)
+{
+        static DEFINE_SPINLOCK(lgr_info_lock);
+        unsigned long flags;
+
+        if (!spin_trylock_irqsave(&lgr_info_lock, flags))
+                return;
+        lgr_info_get(&lgr_info_cur);
+        if (memcmp(&lgr_info_last, &lgr_info_cur, sizeof(lgr_info_cur)) != 0) {
+                debug_event(lgr_dbf, 1, &lgr_info_cur, sizeof(lgr_info_cur));
+                lgr_info_last = lgr_info_cur;
+        }
+        spin_unlock_irqrestore(&lgr_info_lock, flags);
+}
+EXPORT_SYMBOL_GPL(lgr_info_log);
+
+static void lgr_timer_set(void);
+
+/*
+ * LGR timer callback
+ */
+static void lgr_timer_fn(unsigned long ignored)
+{
+        lgr_info_log();
+        lgr_timer_set();
+}
+
+static struct timer_list lgr_timer =
+        TIMER_DEFERRED_INITIALIZER(lgr_timer_fn, 0, 0);
+
+/*
+ * Setup next LGR timer
+ */
+static void lgr_timer_set(void)
+{
+        mod_timer(&lgr_timer, jiffies + LGR_TIMER_INTERVAL_SECS * HZ);
+}
+
+/*
+ * Initialize LGR: Add s390dbf, write initial lgr_info and setup timer
+ */
+static int __init lgr_init(void)
+{
+        lgr_page = (void *) __get_free_pages(GFP_KERNEL, 0);
+        if (!lgr_page)
+                return -ENOMEM;
+        lgr_dbf = debug_register("lgr", 1, 1, sizeof(struct lgr_info));
+        if (!lgr_dbf) {
+                free_page((unsigned long) lgr_page);
+                return -ENOMEM;
+        }
+        debug_register_view(lgr_dbf, &debug_hex_ascii_view);
+        lgr_info_get(&lgr_info_last);
+        debug_event(lgr_dbf, 1, &lgr_info_last, sizeof(lgr_info_last));
+        lgr_timer_set();
+        return 0;
+}
+module_init(lgr_init);