+
+/*
+ * Server Time Protocol (STP) code.
+ */
+static int stp_online;
+static struct stp_sstpi stp_info;
+static void *stp_page;
+
+static void stp_work_fn(struct work_struct *work);
+static DECLARE_WORK(stp_work, stp_work_fn);
+
+static int __init early_parse_stp(char *p)
+{
+ if (strncmp(p, "off", 3) == 0)
+ stp_online = 0;
+ else if (strncmp(p, "on", 2) == 0)
+ stp_online = 1;
+ return 0;
+}
+early_param("stp", early_parse_stp);
+
+/*
+ * Reset STP attachment.
+ */
+static void stp_reset(void)
+{
+ int rc;
+
+ stp_page = alloc_bootmem_pages(PAGE_SIZE);
+ rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000);
+ if (rc == 1)
+ set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags);
+ else if (stp_online) {
+ printk(KERN_WARNING "Running on non STP capable machine.\n");
+ free_bootmem((unsigned long) stp_page, PAGE_SIZE);
+ stp_page = NULL;
+ stp_online = 0;
+ }
+}
+
+static int __init stp_init(void)
+{
+ if (test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags) && stp_online)
+ schedule_work(&stp_work);
+ return 0;
+}
+
+arch_initcall(stp_init);
+
+/*
+ * STP timing alert. There are three causes:
+ * 1) timing status change
+ * 2) link availability change
+ * 3) time control parameter change
+ * In all three cases we are only interested in the clock source state.
+ * If a STP clock source is now available use it.
+ */
+static void stp_timing_alert(struct stp_irq_parm *intparm)
+{
+ if (intparm->tsc || intparm->lac || intparm->tcpc)
+ schedule_work(&stp_work);
+}
+
+/*
+ * STP sync check machine check. This is called when the timing state
+ * changes from the synchronized state to the unsynchronized state.
+ * After a STP sync check the clock is not in sync. The machine check
+ * is broadcasted to all cpus at the same time.
+ */
+void stp_sync_check(void)
+{
+ if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags))
+ return;
+ disable_sync_clock(NULL);
+ schedule_work(&stp_work);
+}
+
+/*
+ * STP island condition machine check. This is called when an attached
+ * server attempts to communicate over an STP link and the servers
+ * have matching CTN ids and have a valid stratum-1 configuration
+ * but the configurations do not match.
+ */
+void stp_island_check(void)
+{
+ if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags))
+ return;
+ disable_sync_clock(NULL);
+ schedule_work(&stp_work);
+}
+
+/*
+ * STP tasklet. Check for the STP state and take over the clock
+ * synchronization if the STP clock source is usable.
+ */
+static void stp_work_fn(struct work_struct *work)
+{
+ struct clock_sync_data stp_sync;
+ unsigned long long old_clock, delta;
+ int rc;
+
+ if (!stp_online) {
+ chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000);
+ return;
+ }
+
+ rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0);
+ if (rc)
+ return;
+
+ rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi));
+ if (rc || stp_info.c == 0)
+ return;
+
+ /*
+ * Catch all other cpus and make them wait until we have
+ * successfully synced the clock. smp_call_function will
+ * return after all other cpus are in clock_sync_cpu_start.
+ */
+ memset(&stp_sync, 0, sizeof(stp_sync));
+ preempt_disable();
+ smp_call_function(clock_sync_cpu_start, &stp_sync, 0);
+ local_irq_disable();
+ enable_sync_clock();
+
+ set_bit(CLOCK_SYNC_STP, &clock_sync_flags);
+ if (test_and_clear_bit(CLOCK_SYNC_ETR, &clock_sync_flags))
+ schedule_work(&etr_work);
+
+ rc = 0;
+ if (stp_info.todoff[0] || stp_info.todoff[1] ||
+ stp_info.todoff[2] || stp_info.todoff[3] ||
+ stp_info.tmd != 2) {
+ old_clock = get_clock();
+ rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0);
+ if (rc == 0) {
+ delta = adjust_time(old_clock, get_clock(), 0);
+ fixup_clock_comparator(delta);
+ rc = chsc_sstpi(stp_page, &stp_info,
+ sizeof(struct stp_sstpi));
+ if (rc == 0 && stp_info.tmd != 2)
+ rc = -EAGAIN;
+ }
+ }
+ if (rc) {
+ disable_sync_clock(NULL);
+ stp_sync.in_sync = -EAGAIN;
+ clear_bit(CLOCK_SYNC_STP, &clock_sync_flags);
+ if (etr_port0_online || etr_port1_online)
+ schedule_work(&etr_work);
+ } else
+ stp_sync.in_sync = 1;
+
+ local_irq_enable();
+ smp_call_function(clock_sync_cpu_end, NULL, 0);
+ preempt_enable();
+}
+
+/*
+ * STP class sysfs interface functions
+ */
+static struct sysdev_class stp_sysclass = {
+ .name = "stp",
+};
+
+static ssize_t stp_ctn_id_show(struct sysdev_class *class, char *buf)
+{
+ if (!stp_online)
+ return -ENODATA;
+ return sprintf(buf, "%016llx\n",
+ *(unsigned long long *) stp_info.ctnid);
+}
+
+static SYSDEV_CLASS_ATTR(ctn_id, 0400, stp_ctn_id_show, NULL);
+
+static ssize_t stp_ctn_type_show(struct sysdev_class *class, char *buf)
+{
+ if (!stp_online)
+ return -ENODATA;
+ return sprintf(buf, "%i\n", stp_info.ctn);
+}
+
+static SYSDEV_CLASS_ATTR(ctn_type, 0400, stp_ctn_type_show, NULL);
+
+static ssize_t stp_dst_offset_show(struct sysdev_class *class, char *buf)
+{
+ if (!stp_online || !(stp_info.vbits & 0x2000))
+ return -ENODATA;
+ return sprintf(buf, "%i\n", (int)(s16) stp_info.dsto);
+}
+
+static SYSDEV_CLASS_ATTR(dst_offset, 0400, stp_dst_offset_show, NULL);
+
+static ssize_t stp_leap_seconds_show(struct sysdev_class *class, char *buf)
+{
+ if (!stp_online || !(stp_info.vbits & 0x8000))
+ return -ENODATA;
+ return sprintf(buf, "%i\n", (int)(s16) stp_info.leaps);
+}
+
+static SYSDEV_CLASS_ATTR(leap_seconds, 0400, stp_leap_seconds_show, NULL);
+
+static ssize_t stp_stratum_show(struct sysdev_class *class, char *buf)
+{
+ if (!stp_online)
+ return -ENODATA;
+ return sprintf(buf, "%i\n", (int)(s16) stp_info.stratum);
+}
+
+static SYSDEV_CLASS_ATTR(stratum, 0400, stp_stratum_show, NULL);
+
+static ssize_t stp_time_offset_show(struct sysdev_class *class, char *buf)
+{
+ if (!stp_online || !(stp_info.vbits & 0x0800))
+ return -ENODATA;
+ return sprintf(buf, "%i\n", (int) stp_info.tto);
+}
+
+static SYSDEV_CLASS_ATTR(time_offset, 0400, stp_time_offset_show, NULL);
+
+static ssize_t stp_time_zone_offset_show(struct sysdev_class *class, char *buf)
+{
+ if (!stp_online || !(stp_info.vbits & 0x4000))
+ return -ENODATA;
+ return sprintf(buf, "%i\n", (int)(s16) stp_info.tzo);
+}
+
+static SYSDEV_CLASS_ATTR(time_zone_offset, 0400,
+ stp_time_zone_offset_show, NULL);
+
+static ssize_t stp_timing_mode_show(struct sysdev_class *class, char *buf)
+{
+ if (!stp_online)
+ return -ENODATA;
+ return sprintf(buf, "%i\n", stp_info.tmd);
+}
+
+static SYSDEV_CLASS_ATTR(timing_mode, 0400, stp_timing_mode_show, NULL);
+
+static ssize_t stp_timing_state_show(struct sysdev_class *class, char *buf)
+{
+ if (!stp_online)
+ return -ENODATA;
+ return sprintf(buf, "%i\n", stp_info.tst);
+}
+
+static SYSDEV_CLASS_ATTR(timing_state, 0400, stp_timing_state_show, NULL);
+
+static ssize_t stp_online_show(struct sysdev_class *class, char *buf)
+{
+ return sprintf(buf, "%i\n", stp_online);
+}
+
+static ssize_t stp_online_store(struct sysdev_class *class,
+ const char *buf, size_t count)
+{
+ unsigned int value;
+
+ value = simple_strtoul(buf, NULL, 0);
+ if (value != 0 && value != 1)
+ return -EINVAL;
+ if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
+ return -EOPNOTSUPP;
+ stp_online = value;
+ schedule_work(&stp_work);
+ return count;
+}
+
+/*
+ * Can't use SYSDEV_CLASS_ATTR because the attribute should be named
+ * stp/online but attr_online already exists in this file ..
+ */
+static struct sysdev_class_attribute attr_stp_online = {
+ .attr = { .name = "online", .mode = 0600 },
+ .show = stp_online_show,
+ .store = stp_online_store,
+};
+
+static struct sysdev_class_attribute *stp_attributes[] = {
+ &attr_ctn_id,
+ &attr_ctn_type,
+ &attr_dst_offset,
+ &attr_leap_seconds,
+ &attr_stp_online,
+ &attr_stratum,
+ &attr_time_offset,
+ &attr_time_zone_offset,
+ &attr_timing_mode,
+ &attr_timing_state,
+ NULL
+};
+
+static int __init stp_init_sysfs(void)
+{
+ struct sysdev_class_attribute **attr;
+ int rc;
+
+ rc = sysdev_class_register(&stp_sysclass);
+ if (rc)
+ goto out;
+ for (attr = stp_attributes; *attr; attr++) {
+ rc = sysdev_class_create_file(&stp_sysclass, *attr);
+ if (rc)
+ goto out_unreg;
+ }
+ return 0;
+out_unreg:
+ for (; attr >= stp_attributes; attr--)
+ sysdev_class_remove_file(&stp_sysclass, *attr);
+ sysdev_class_unregister(&stp_sysclass);
+out:
+ return rc;
+}
+
+device_initcall(stp_init_sysfs);