x86/asm/tsc: Rename native_read_tsc() to rdtsc()

Now that there is no paravirt TSC, the "native" is
inappropriate. The function does RDTSC, so give it the obvious
name: rdtsc().

Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm ML <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/fd43e16281991f096c1e4d21574d9e1402c62d39.1434501121.git.luto@kernel.org
[ Ported it to v4.2-rc1. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

19 files changed, 49 insertions, 40 deletions

diff --git a/arch/x86/boot/compressed/aslr.c b/arch/x86/boot/compressed/aslr.c
index ea33236190b1..6a9b96b4624d 100644
--- a/arch/x86/boot/compressed/aslr.c
+++ b/arch/x86/boot/compressed/aslr.c
@@ -82,7 +82,7 @@ static unsigned long get_random_long(void)
 
 	if (has_cpuflag(X86_FEATURE_TSC)) {
 		debug_putstr(" RDTSC");
-		raw = native_read_tsc();
+		raw = rdtsc();
 
 		random ^= raw;
 		use_i8254 = false;
diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c
index 972b488ac16a..0340d93c18ca 100644
--- a/arch/x86/entry/vdso/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vclock_gettime.c
@@ -186,7 +186,7 @@ notrace static cycle_t vread_tsc(void)
 	 * but no one has ever seen it happen.
 	 */
 	rdtsc_barrier();
-	ret = (cycle_t)native_read_tsc();
+	ret = (cycle_t)rdtsc();
 
 	last = gtod->cycle_last;
 
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index c89ed6ceed02..ff0c120dafe5 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -109,7 +109,16 @@ notrace static inline int native_write_msr_safe(unsigned int msr,
 extern int rdmsr_safe_regs(u32 regs[8]);
 extern int wrmsr_safe_regs(u32 regs[8]);
 
-static __always_inline unsigned long long native_read_tsc(void)
+/**
+ * rdtsc() - returns the current TSC without ordering constraints
+ *
+ * rdtsc() returns the result of RDTSC as a 64-bit integer.  The
+ * only ordering constraint it supplies is the ordering implied by
+ * "asm volatile": it will put the RDTSC in the place you expect.  The
+ * CPU can and will speculatively execute that RDTSC, though, so the
+ * results can be non-monotonic if compared on different CPUs.
+ */
+static __always_inline unsigned long long rdtsc(void)
 {
 	DECLARE_ARGS(val, low, high);
 
diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
index 2bd69d62c623..5c490db62e32 100644
--- a/arch/x86/include/asm/pvclock.h
+++ b/arch/x86/include/asm/pvclock.h
@@ -62,7 +62,7 @@ static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift)
 static __always_inline
 u64 pvclock_get_nsec_offset(const struct pvclock_vcpu_time_info *src)
 {
-	u64 delta = native_read_tsc() - src->tsc_timestamp;
+	u64 delta = rdtsc() - src->tsc_timestamp;
 	return pvclock_scale_delta(delta, src->tsc_to_system_mul,
 				   src->tsc_shift);
 }
diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h
index bc5fa2af112e..58505f01962f 100644
--- a/arch/x86/include/asm/stackprotector.h
+++ b/arch/x86/include/asm/stackprotector.h
@@ -72,7 +72,7 @@ static __always_inline void boot_init_stack_canary(void)
 	 * on during the bootup the random pool has true entropy too.
 	 */
 	get_random_bytes(&canary, sizeof(canary));
-	tsc = native_read_tsc();
+	tsc = rdtsc();
 	canary += tsc + (tsc << 32UL);
 
 	current->stack_canary = canary;
diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h
index b4883902948b..3df7675debcf 100644
--- a/arch/x86/include/asm/tsc.h
+++ b/arch/x86/include/asm/tsc.h
@@ -26,7 +26,7 @@ static inline cycles_t get_cycles(void)
 		return 0;
 #endif
 
-	return native_read_tsc();
+	return rdtsc();
 }
 
 extern void tsc_init(void);
diff --git a/arch/x86/kernel/apb_timer.c b/arch/x86/kernel/apb_timer.c
index 25efa534c4e4..222a57076039 100644
--- a/arch/x86/kernel/apb_timer.c
+++ b/arch/x86/kernel/apb_timer.c
@@ -263,7 +263,7 @@ static int apbt_clocksource_register(void)
 
 	/* Verify whether apbt counter works */
 	t1 = dw_apb_clocksource_read(clocksource_apbt);
-	start = native_read_tsc();
+	start = rdtsc();
 
 	/*
 	 * We don't know the TSC frequency yet, but waiting for
@@ -273,7 +273,7 @@ static int apbt_clocksource_register(void)
 	 */
 	do {
 		rep_nop();
-		now = native_read_tsc();
+		now = rdtsc();
 	} while ((now - start) < 200000UL);
 
 	/* APBT is the only always on clocksource, it has to work! */
@@ -390,13 +390,13 @@ unsigned long apbt_quick_calibrate(void)
 	old = dw_apb_clocksource_read(clocksource_apbt);
 	old += loop;
 
-	t1 = native_read_tsc();
+	t1 = rdtsc();
 
 	do {
 		new = dw_apb_clocksource_read(clocksource_apbt);
 	} while (new < old);
 
-	t2 = native_read_tsc();
+	t2 = rdtsc();
 
 	shift = 5;
 	if (unlikely(loop >> shift == 0)) {
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 51af1ed1ae2e..0d71cd9b4a50 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -457,7 +457,7 @@ static int lapic_next_deadline(unsigned long delta,
 {
 	u64 tsc;
 
-	tsc = native_read_tsc();
+	tsc = rdtsc();
 	wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR));
 	return 0;
 }
@@ -592,7 +592,7 @@ static void __init lapic_cal_handler(struct clock_event_device *dev)
 	unsigned long pm = acpi_pm_read_early();
 
 	if (cpu_has_tsc)
-		tsc = native_read_tsc();
+		tsc = rdtsc();
 
 	switch (lapic_cal_loops++) {
 	case 0:
@@ -1209,7 +1209,7 @@ void setup_local_APIC(void)
 	long long max_loops = cpu_khz ? cpu_khz : 1000000;
 
 	if (cpu_has_tsc)
-		tsc = native_read_tsc();
+		tsc = rdtsc();
 
 	if (disable_apic) {
 		disable_ioapic_support();
@@ -1293,7 +1293,7 @@ void setup_local_APIC(void)
 		}
 		if (queued) {
 			if (cpu_has_tsc && cpu_khz) {
-				ntsc = native_read_tsc();
+				ntsc = rdtsc();
 				max_loops = (cpu_khz << 10) - (ntsc - tsc);
 			} else
 				max_loops--;
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index a69710db6112..51ad2af84a72 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -125,10 +125,10 @@ static void init_amd_k6(struct cpuinfo_x86 *c)
 
 		n = K6_BUG_LOOP;
 		f_vide = vide;
-		d = native_read_tsc();
+		d = rdtsc();
 		while (n--)
 			f_vide();
-		d2 = native_read_tsc();
+		d2 = rdtsc();
 		d = d2-d;
 
 		if (d > 20*K6_BUG_LOOP)
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index a5283d2d0094..96cceccd11b4 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -125,7 +125,7 @@ void mce_setup(struct mce *m)
 {
 	memset(m, 0, sizeof(struct mce));
 	m->cpu = m->extcpu = smp_processor_id();
-	m->tsc = native_read_tsc();
+	m->tsc = rdtsc();
 	/* We hope get_seconds stays lockless */
 	m->time = get_seconds();
 	m->cpuvendor = boot_cpu_data.x86_vendor;
@@ -1784,7 +1784,7 @@ static void collect_tscs(void *data)
 {
 	unsigned long *cpu_tsc = (unsigned long *)data;
 
-	cpu_tsc[smp_processor_id()] = native_read_tsc();
+	cpu_tsc[smp_processor_id()] = rdtsc();
 }
 
 static int mce_apei_read_done;
diff --git a/arch/x86/kernel/espfix_64.c b/arch/x86/kernel/espfix_64.c
index 334a2a9c034d..67315cd0132c 100644
--- a/arch/x86/kernel/espfix_64.c
+++ b/arch/x86/kernel/espfix_64.c
@@ -110,7 +110,7 @@ static void init_espfix_random(void)
 	 */
 	if (!arch_get_random_long(&rand)) {
 		/* The constant is an arbitrary large prime */
-		rand = native_read_tsc();
+		rand = rdtsc();
 		rand *= 0xc345c6b72fd16123UL;
 	}
 
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index cc390fe69b71..f75c5908c7a6 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -735,7 +735,7 @@ static int hpet_clocksource_register(void)
 
 	/* Verify whether hpet counter works */
 	t1 = hpet_readl(HPET_COUNTER);
-	start = native_read_tsc();
+	start = rdtsc();
 
 	/*
 	 * We don't know the TSC frequency yet, but waiting for
@@ -745,7 +745,7 @@ static int hpet_clocksource_register(void)
 	 */
 	do {
 		rep_nop();
-		now = native_read_tsc();
+		now = rdtsc();
 	} while ((now - start) < 200000UL);
 
 	if (t1 == hpet_readl(HPET_COUNTER)) {
diff --git a/arch/x86/kernel/trace_clock.c b/arch/x86/kernel/trace_clock.c
index bd8f4d41bd56..67efb8c96fc4 100644
--- a/arch/x86/kernel/trace_clock.c
+++ b/arch/x86/kernel/trace_clock.c
@@ -15,7 +15,7 @@ u64 notrace trace_clock_x86_tsc(void)
 	u64 ret;
 
 	rdtsc_barrier();
-	ret = native_read_tsc();
+	ret = rdtsc();
 
 	return ret;
 }
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index e66f5dcaeb63..21d6e04e3e82 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -248,7 +248,7 @@ static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
 
 	data = cyc2ns_write_begin(cpu);
 
-	tsc_now = native_read_tsc();
+	tsc_now = rdtsc();
 	ns_now = cycles_2_ns(tsc_now);
 
 	/*
@@ -290,7 +290,7 @@ u64 native_sched_clock(void)
 	}
 
 	/* read the Time Stamp Counter: */
-	tsc_now = native_read_tsc();
+	tsc_now = rdtsc();
 
 	/* return the value in ns */
 	return cycles_2_ns(tsc_now);
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 954e98a8c2e3..2f0ade48614f 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1172,7 +1172,7 @@ void wait_lapic_expire(struct kvm_vcpu *vcpu)
 
 	tsc_deadline = apic->lapic_timer.expired_tscdeadline;
 	apic->lapic_timer.expired_tscdeadline = 0;
-	guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu, native_read_tsc());
+	guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu, rdtsc());
 	trace_kvm_wait_lapic_expire(vcpu->vcpu_id, guest_tsc - tsc_deadline);
 
 	/* __delay is delay_tsc whenever the hardware has TSC, thus always.  */
@@ -1240,7 +1240,7 @@ static void start_apic_timer(struct kvm_lapic *apic)
 		local_irq_save(flags);
 
 		now = apic->lapic_timer.timer.base->get_time();
-		guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu, native_read_tsc());
+		guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu, rdtsc());
 		if (likely(tscdeadline > guest_tsc)) {
 			ns = (tscdeadline - guest_tsc) * 1000000ULL;
 			do_div(ns, this_tsc_khz);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 602b974a60a6..8dfbad7a2c44 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1080,7 +1080,7 @@ static u64 svm_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
 {
 	u64 tsc;
 
-	tsc = svm_scale_tsc(vcpu, native_read_tsc());
+	tsc = svm_scale_tsc(vcpu, rdtsc());
 
 	return target_tsc - tsc;
 }
@@ -3079,7 +3079,7 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	switch (msr_info->index) {
 	case MSR_IA32_TSC: {
 		msr_info->data = svm->vmcb->control.tsc_offset +
-			svm_scale_tsc(vcpu, native_read_tsc());
+			svm_scale_tsc(vcpu, rdtsc());
 
 		break;
 	}
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 4fa1ccad7beb..10d69a6df14f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2236,7 +2236,7 @@ static u64 guest_read_tsc(void)
 {
 	u64 host_tsc, tsc_offset;
 
-	host_tsc = native_read_tsc();
+	host_tsc = rdtsc();
 	tsc_offset = vmcs_read64(TSC_OFFSET);
 	return host_tsc + tsc_offset;
 }
@@ -2317,7 +2317,7 @@ static void vmx_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment, bool ho
 
 static u64 vmx_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
 {
-	return target_tsc - native_read_tsc();
+	return target_tsc - rdtsc();
 }
 
 static bool guest_cpuid_has_vmx(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f771058cfb5c..dfa97139282d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1455,7 +1455,7 @@ static cycle_t read_tsc(void)
 	 * but no one has ever seen it happen.
 	 */
 	rdtsc_barrier();
-	ret = (cycle_t)native_read_tsc();
+	ret = (cycle_t)rdtsc();
 
 	last = pvclock_gtod_data.clock.cycle_last;
 
@@ -1646,7 +1646,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
 		return 1;
 	}
 	if (!use_master_clock) {
-		host_tsc = native_read_tsc();
+		host_tsc = rdtsc();
 		kernel_ns = get_kernel_ns();
 	}
 
@@ -2810,7 +2810,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 
 	if (unlikely(vcpu->cpu != cpu) || check_tsc_unstable()) {
 		s64 tsc_delta = !vcpu->arch.last_host_tsc ? 0 :
-				native_read_tsc() - vcpu->arch.last_host_tsc;
+				rdtsc() - vcpu->arch.last_host_tsc;
 		if (tsc_delta < 0)
 			mark_tsc_unstable("KVM discovered backwards TSC");
 		if (check_tsc_unstable()) {
@@ -2838,7 +2838,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 {
 	kvm_x86_ops->vcpu_put(vcpu);
 	kvm_put_guest_fpu(vcpu);
-	vcpu->arch.last_host_tsc = native_read_tsc();
+	vcpu->arch.last_host_tsc = rdtsc();
 }
 
 static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
@@ -6623,7 +6623,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 		hw_breakpoint_restore();
 
 	vcpu->arch.last_guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu,
-							   native_read_tsc());
+							   rdtsc());
 
 	vcpu->mode = OUTSIDE_GUEST_MODE;
 	smp_wmb();
@@ -7437,7 +7437,7 @@ int kvm_arch_hardware_enable(void)
 	if (ret != 0)
 		return ret;
 
-	local_tsc = native_read_tsc();
+	local_tsc = rdtsc();
 	stable = !check_tsc_unstable();
 	list_for_each_entry(kvm, &vm_list, vm_list) {
 		kvm_for_each_vcpu(i, vcpu, kvm) {
diff --git a/arch/x86/lib/delay.c b/arch/x86/lib/delay.c
index 35115f3786a9..f24bc59ab0a0 100644
--- a/arch/x86/lib/delay.c
+++ b/arch/x86/lib/delay.c
@@ -55,10 +55,10 @@ static void delay_tsc(unsigned long __loops)
 	preempt_disable();
 	cpu = smp_processor_id();
 	rdtsc_barrier();
-	bclock = native_read_tsc();
+	bclock = rdtsc();
 	for (;;) {
 		rdtsc_barrier();
-		now = native_read_tsc();
+		now = rdtsc();
 		if ((now - bclock) >= loops)
 			break;
 
@@ -80,7 +80,7 @@ static void delay_tsc(unsigned long __loops)
 			loops -= (now - bclock);
 			cpu = smp_processor_id();
 			rdtsc_barrier();
-			bclock = native_read_tsc();
+			bclock = rdtsc();
 		}
 	}
 	preempt_enable();
@@ -100,7 +100,7 @@ void use_tsc_delay(void)
 int read_current_timer(unsigned long *timer_val)
 {
 	if (delay_fn == delay_tsc) {
-		*timer_val = native_read_tsc();
+		*timer_val = rdtsc();
 		return 0;
 	}
 	return -1;