1 files changed, 107 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
new file mode 100644
index 000000000..d6b078e9f
--- /dev/null
+++ b/arch/x86/include/asm/pvclock.h
@@ -0,0 +1,107 @@
+#ifndef _ASM_X86_PVCLOCK_H
+#define _ASM_X86_PVCLOCK_H
+
+#include <linux/clocksource.h>
+#include <asm/pvclock-abi.h>
+
+/* some helper functions for xen and kvm pv clock sources */
+cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
+u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src);
+void pvclock_set_flags(u8 flags);
+unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);
+void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
+			    struct pvclock_vcpu_time_info *vcpu,
+			    struct timespec *ts);
+void pvclock_resume(void);
+
+void pvclock_touch_watchdogs(void);
+
+/*
+ * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
+ * yielding a 64-bit result.
+ */
+static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift)
+{
+	u64 product;
+#ifdef __i386__
+	u32 tmp1, tmp2;
+#else
+	ulong tmp;
+#endif
+
+	if (shift < 0)
+		delta >>= -shift;
+	else
+		delta <<= shift;
+
+#ifdef __i386__
+	__asm__ (
+		"mul  %5       ; "
+		"mov  %4,%%eax ; "
+		"mov  %%edx,%4 ; "
+		"mul  %5       ; "
+		"xor  %5,%5    ; "
+		"add  %4,%%eax ; "
+		"adc  %5,%%edx ; "
+		: "=A" (product), "=r" (tmp1), "=r" (tmp2)
+		: "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) );
+#elif defined(__x86_64__)
+	__asm__ (
+		"mulq %[mul_frac] ; shrd $32, %[hi], %[lo]"
+		: [lo]"=a"(product),
+		  [hi]"=d"(tmp)
+		: "0"(delta),
+		  [mul_frac]"rm"((u64)mul_frac));
+#else
+#error implement me!
+#endif
+
+	return product;
+}
+
+static __always_inline
+u64 pvclock_get_nsec_offset(const struct pvclock_vcpu_time_info *src)
+{
+	u64 delta = __native_read_tsc() - src->tsc_timestamp;
+	return pvclock_scale_delta(delta, src->tsc_to_system_mul,
+				   src->tsc_shift);
+}
+
+static __always_inline
+unsigned __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src,
+			       cycle_t *cycles, u8 *flags)
+{
+	unsigned version;
+	cycle_t ret, offset;
+	u8 ret_flags;
+
+	version = src->version;
+	/* Note: emulated platforms which do not advertise SSE2 support
+	 * result in kvmclock not using the necessary RDTSC barriers.
+	 * Without barriers, it is possible that RDTSC instruction reads from
+	 * the time stamp counter outside rdtsc_barrier protected section
+	 * below, resulting in violation of monotonicity.
+	 */
+	rdtsc_barrier();
+	offset = pvclock_get_nsec_offset(src);
+	ret = src->system_time + offset;
+	ret_flags = src->flags;
+	rdtsc_barrier();
+
+	*cycles = ret;
+	*flags = ret_flags;
+	return version;
+}
+
+struct pvclock_vsyscall_time_info {
+	struct pvclock_vcpu_time_info pvti;
+} __attribute__((__aligned__(SMP_CACHE_BYTES)));
+
+#define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info)
+#define PVCLOCK_VSYSCALL_NR_PAGES (((NR_CPUS-1)/(PAGE_SIZE/PVTI_SIZE))+1)
+
+int __init pvclock_init_vsyscall(struct pvclock_vsyscall_time_info *i,
+				 int size);
+struct pvclock_vcpu_time_info *pvclock_get_vsyscall_time_info(int cpu);
+
+#endif /* _ASM_X86_PVCLOCK_H */