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authorRuss Anderson <rja@sgi.com>2008-07-09 15:27:19 -0500
committerIngo Molnar <mingo@elte.hu>2008-07-18 14:35:14 +0200
commit7019cc2dd6fafcdc6b104005482dc910dcdbb797 (patch)
tree0f8e67c0b5146543d407dc9f07ace6aeb4b0bd12 /arch/x86/kernel/genx2apic_uv_x.c
parent5b664cb235e97afbf34db9c4d77f08ebd725335e (diff)
x86 BIOS interface for RTC on SGI UV
Real-time code needs to know the number of cycles per second on SGI UV. The information is provided via a run time BIOS call. This patch provides the linux side of that interface. This is the first of several run time BIOS calls to be defined in uv/bios.h and bios_uv.c. Note that BIOS_CALL() is just a stub for now. The bios side is being worked on. Signed-off-by: Russ Anderson <rja@sgi.com> Cc: Jack Steiner <steiner@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/genx2apic_uv_x.c')
-rw-r--r--arch/x86/kernel/genx2apic_uv_x.c23
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 711f11c30b0..3c392934069 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));