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-rw-r--r--arch/x86/lib/delay_64.c57
1 files changed, 57 insertions, 0 deletions
diff --git a/arch/x86/lib/delay_64.c b/arch/x86/lib/delay_64.c
new file mode 100644
index 00000000000..2dbebd30834
--- /dev/null
+++ b/arch/x86/lib/delay_64.c
@@ -0,0 +1,57 @@
+/*
+ * Precise Delay Loops for x86-64
+ *
+ * Copyright (C) 1993 Linus Torvalds
+ * Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
+ *
+ * The __delay function must _NOT_ be inlined as its execution time
+ * depends wildly on alignment on many x86 processors.
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <asm/delay.h>
+#include <asm/msr.h>
+
+#ifdef CONFIG_SMP
+#include <asm/smp.h>
+#endif
+
+int read_current_timer(unsigned long *timer_value)
+{
+ rdtscll(*timer_value);
+ return 0;
+}
+
+void __delay(unsigned long loops)
+{
+ unsigned bclock, now;
+
+ rdtscl(bclock);
+ do
+ {
+ rep_nop();
+ rdtscl(now);
+ }
+ while((now-bclock) < loops);
+}
+EXPORT_SYMBOL(__delay);
+
+inline void __const_udelay(unsigned long xloops)
+{
+ __delay(((xloops * HZ * cpu_data[raw_smp_processor_id()].loops_per_jiffy) >> 32) + 1);
+}
+EXPORT_SYMBOL(__const_udelay);
+
+void __udelay(unsigned long usecs)
+{
+ __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */
+}
+EXPORT_SYMBOL(__udelay);
+
+void __ndelay(unsigned long nsecs)
+{
+ __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */
+}
+EXPORT_SYMBOL(__ndelay);