1 files changed, 23 insertions, 0 deletions

diff --git a/arch/x86/kernel/genx2apic_uv_x.c b/arch/x86/kernel/genx2apic_uv_x.c
index 711f11c30b06..3c3929340692 100644
--- a/arch/x86/kernel/genx2apic_uv_x.c
+++ b/arch/x86/kernel/genx2apic_uv_x.c
@@ -24,6 +24,7 @@
 #include <asm/pgtable.h>
 #include <asm/uv/uv_mmrs.h>
 #include <asm/uv/uv_hub.h>
+#include <asm/uv/bios.h>
 
 DEFINE_PER_CPU(struct uv_hub_info_s, __uv_hub_info);
 EXPORT_PER_CPU_SYMBOL_GPL(__uv_hub_info);
@@ -40,6 +41,9 @@ EXPORT_SYMBOL_GPL(uv_cpu_to_blade);
 short uv_possible_blades;
 EXPORT_SYMBOL_GPL(uv_possible_blades);
 
+unsigned long sn_rtc_cycles_per_second;
+EXPORT_SYMBOL(sn_rtc_cycles_per_second);
+
 /* Start with all IRQs pointing to boot CPU.  IRQ balancing will shift them. */
 
 static cpumask_t uv_target_cpus(void)
@@ -272,6 +276,23 @@ static __init void map_mmioh_high(int max_pnode)
                 map_high("MMIOH", mmioh.s.base, shift, map_uc);
 }
 
+static __init void uv_rtc_init(void)
+{
+        long status, ticks_per_sec, drift;
+
+        status =
+            x86_bios_freq_base(BIOS_FREQ_BASE_REALTIME_CLOCK, &ticks_per_sec,
+                                        &drift);
+        if (status != 0 || ticks_per_sec < 100000) {
+                printk(KERN_WARNING
+                        "unable to determine platform RTC clock frequency, "
+                        "guessing.\n");
+                /* BIOS gives wrong value for clock freq. so guess */
+                sn_rtc_cycles_per_second = 1000000000000UL / 30000UL;
+        } else
+                sn_rtc_cycles_per_second = ticks_per_sec;
+}
+
 static __init void uv_system_init(void)
 {
         union uvh_si_addr_map_config_u m_n_config;
@@ -326,6 +347,8 @@ static __init void uv_system_init(void)
         gnode_upper = (((unsigned long)node_id.s.node_id) &
                        ~((1 << n_val) - 1)) << m_val;
 
+        uv_rtc_init();
+
         for_each_present_cpu(cpu) {
                 nid = cpu_to_node(cpu);
                 pnode = uv_apicid_to_pnode(per_cpu(x86_cpu_to_apicid, cpu));