[IA64] Fix CONFIG_PRINTK_TIME
There were two problems with enabling the PRINTK_TIME config
option:
1) The first calls to printk() occur before per-cpu data virtual
address is pinned into the TLB, so sched_clock() can fault.
2) sched_clock() is based on ar.itc, which may not be synchronized
across cpus.
Ken Chen started this patch, Tony Luck tinkered with it, and Jes
Sorensen perfected it.
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/sn/kernel/setup.c b/arch/ia64/sn/kernel/setup.c
index ee36bff..6ea5b8a 100644
--- a/arch/ia64/sn/kernel/setup.c
+++ b/arch/ia64/sn/kernel/setup.c
@@ -67,6 +67,7 @@
extern void (*ia64_mark_idle) (int);
extern void snidle(int);
extern unsigned char acpi_kbd_controller_present;
+extern unsigned long long (*ia64_printk_clock)(void);
unsigned long sn_rtc_cycles_per_second;
EXPORT_SYMBOL(sn_rtc_cycles_per_second);
@@ -372,6 +373,16 @@
}
}
+static unsigned long sn2_rtc_initial;
+
+static unsigned long long ia64_sn2_printk_clock(void)
+{
+ unsigned long rtc_now = rtc_time();
+
+ return (rtc_now - sn2_rtc_initial) *
+ (1000000000 / sn_rtc_cycles_per_second);
+}
+
/**
* sn_setup - SN platform setup routine
* @cmdline_p: kernel command line
@@ -386,6 +397,7 @@
u32 version = sn_sal_rev();
extern void sn_cpu_init(void);
+ sn2_rtc_initial = rtc_time();
ia64_sn_plat_set_error_handling_features(); // obsolete
ia64_sn_set_os_feature(OSF_MCA_SLV_TO_OS_INIT_SLV);
ia64_sn_set_os_feature(OSF_FEAT_LOG_SBES);
@@ -437,19 +449,6 @@
*/
build_cnode_tables();
- /*
- * Old PROMs do not provide an ACPI FADT. Disable legacy keyboard
- * support here so we don't have to listen to failed keyboard probe
- * messages.
- */
- if (version <= 0x0209 && acpi_kbd_controller_present) {
- printk(KERN_INFO "Disabling legacy keyboard support as prom "
- "is too old and doesn't provide FADT\n");
- acpi_kbd_controller_present = 0;
- }
-
- printk("SGI SAL version %x.%02x\n", version >> 8, version & 0x00FF);
-
status =
ia64_sal_freq_base(SAL_FREQ_BASE_REALTIME_CLOCK, &ticks_per_sec,
&drift);
@@ -463,6 +462,21 @@
platform_intr_list[ACPI_INTERRUPT_CPEI] = IA64_CPE_VECTOR;
+ ia64_printk_clock = ia64_sn2_printk_clock;
+
+ /*
+ * Old PROMs do not provide an ACPI FADT. Disable legacy keyboard
+ * support here so we don't have to listen to failed keyboard probe
+ * messages.
+ */
+ if (version <= 0x0209 && acpi_kbd_controller_present) {
+ printk(KERN_INFO "Disabling legacy keyboard support as prom "
+ "is too old and doesn't provide FADT\n");
+ acpi_kbd_controller_present = 0;
+ }
+
+ printk("SGI SAL version %x.%02x\n", version >> 8, version & 0x00FF);
+
/*
* we set the default root device to /dev/hda
* to make simulation easy