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-rw-r--r--arch/x86/include/asm/pvclock.h106
1 files changed, 106 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..19b695ff2
--- /dev/null
+++ b/arch/x86/include/asm/pvclock.h
@@ -0,0 +1,106 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_PVCLOCK_H
+#define _ASM_X86_PVCLOCK_H
+
+#include <asm/clocksource.h>
+#include <asm/pvclock-abi.h>
+
+/* some helper functions for xen and kvm pv clock sources */
+u64 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 timespec64 *ts);
+void pvclock_resume(void);
+
+void pvclock_touch_watchdogs(void);
+
+static __always_inline
+unsigned pvclock_read_begin(const struct pvclock_vcpu_time_info *src)
+{
+ unsigned version = src->version & ~1;
+ /* Make sure that the version is read before the data. */
+ virt_rmb();
+ return version;
+}
+
+static __always_inline
+bool pvclock_read_retry(const struct pvclock_vcpu_time_info *src,
+ unsigned version)
+{
+ /* Make sure that the version is re-read after the data. */
+ virt_rmb();
+ return unlikely(version != src->version);
+}
+
+/*
+ * 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_read_cycles(const struct pvclock_vcpu_time_info *src, u64 tsc)
+{
+ u64 delta = tsc - src->tsc_timestamp;
+ u64 offset = pvclock_scale_delta(delta, src->tsc_to_system_mul,
+ src->tsc_shift);
+ return src->system_time + offset;
+}
+
+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)
+
+#ifdef CONFIG_PARAVIRT_CLOCK
+void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti);
+struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void);
+#else
+static inline struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void)
+{
+ return NULL;
+}
+#endif
+
+#endif /* _ASM_X86_PVCLOCK_H */