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Diffstat (limited to 'arch/x86_64/kernel/hpet.c')
-rw-r--r--arch/x86_64/kernel/hpet.c109
1 files changed, 44 insertions, 65 deletions
diff --git a/arch/x86_64/kernel/hpet.c b/arch/x86_64/kernel/hpet.c
index 65a0edd71a1..8cf0b8a1377 100644
--- a/arch/x86_64/kernel/hpet.c
+++ b/arch/x86_64/kernel/hpet.c
@@ -12,6 +12,12 @@
#include <asm/timex.h>
#include <asm/hpet.h>
+#define HPET_MASK 0xFFFFFFFF
+#define HPET_SHIFT 22
+
+/* FSEC = 10^-15 NSEC = 10^-9 */
+#define FSEC_PER_NSEC 1000000
+
int nohpet __initdata;
unsigned long hpet_address;
@@ -106,9 +112,31 @@ int hpet_timer_stop_set_go(unsigned long tick)
return 0;
}
+static cycle_t read_hpet(void)
+{
+ return (cycle_t)hpet_readl(HPET_COUNTER);
+}
+
+static cycle_t __vsyscall_fn vread_hpet(void)
+{
+ return readl((void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0);
+}
+
+struct clocksource clocksource_hpet = {
+ .name = "hpet",
+ .rating = 250,
+ .read = read_hpet,
+ .mask = (cycle_t)HPET_MASK,
+ .mult = 0, /* set below */
+ .shift = HPET_SHIFT,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+ .vread = vread_hpet,
+};
+
int hpet_arch_init(void)
{
unsigned int id;
+ u64 tmp;
if (!hpet_address)
return -1;
@@ -132,6 +160,22 @@ int hpet_arch_init(void)
hpet_use_timer = (id & HPET_ID_LEGSUP);
+ /*
+ * hpet period is in femto seconds per cycle
+ * so we need to convert this to ns/cyc units
+ * aproximated by mult/2^shift
+ *
+ * fsec/cyc * 1nsec/1000000fsec = nsec/cyc = mult/2^shift
+ * fsec/cyc * 1ns/1000000fsec * 2^shift = mult
+ * fsec/cyc * 2^shift * 1nsec/1000000fsec = mult
+ * (fsec/cyc << shift)/1000000 = mult
+ * (hpet_period << shift)/FSEC_PER_NSEC = mult
+ */
+ tmp = (u64)hpet_period << HPET_SHIFT;
+ do_div(tmp, FSEC_PER_NSEC);
+ clocksource_hpet.mult = (u32)tmp;
+ clocksource_register(&clocksource_hpet);
+
return hpet_timer_stop_set_go(hpet_tick);
}
@@ -444,68 +488,3 @@ static int __init nohpet_setup(char *s)
}
__setup("nohpet", nohpet_setup);
-
-#define HPET_MASK 0xFFFFFFFF
-#define HPET_SHIFT 22
-
-/* FSEC = 10^-15 NSEC = 10^-9 */
-#define FSEC_PER_NSEC 1000000
-
-static void *hpet_ptr;
-
-static cycle_t read_hpet(void)
-{
- return (cycle_t)readl(hpet_ptr);
-}
-
-static cycle_t __vsyscall_fn vread_hpet(void)
-{
- return readl((void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0);
-}
-
-struct clocksource clocksource_hpet = {
- .name = "hpet",
- .rating = 250,
- .read = read_hpet,
- .mask = (cycle_t)HPET_MASK,
- .mult = 0, /* set below */
- .shift = HPET_SHIFT,
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
- .vread = vread_hpet,
-};
-
-static int __init init_hpet_clocksource(void)
-{
- unsigned long hpet_period;
- void __iomem *hpet_base;
- u64 tmp;
-
- if (!hpet_address)
- return -ENODEV;
-
- /* calculate the hpet address: */
- hpet_base = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
- hpet_ptr = hpet_base + HPET_COUNTER;
-
- /* calculate the frequency: */
- hpet_period = readl(hpet_base + HPET_PERIOD);
-
- /*
- * hpet period is in femto seconds per cycle
- * so we need to convert this to ns/cyc units
- * aproximated by mult/2^shift
- *
- * fsec/cyc * 1nsec/1000000fsec = nsec/cyc = mult/2^shift
- * fsec/cyc * 1ns/1000000fsec * 2^shift = mult
- * fsec/cyc * 2^shift * 1nsec/1000000fsec = mult
- * (fsec/cyc << shift)/1000000 = mult
- * (hpet_period << shift)/FSEC_PER_NSEC = mult
- */
- tmp = (u64)hpet_period << HPET_SHIFT;
- do_div(tmp, FSEC_PER_NSEC);
- clocksource_hpet.mult = (u32)tmp;
-
- return clocksource_register(&clocksource_hpet);
-}
-
-module_init(init_hpet_clocksource);