Merge tag 'v4.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into fbdev-for-next

Linux 4.15-rc5

1 files changed, 23 insertions, 11 deletions

diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index 5dc7ea4b6bc4..b2ccce5fb071 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -913,22 +913,29 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev,
 	struct cpuidle_state *state = &drv->states[index];
 	unsigned long eax = flg2MWAIT(state->flags);
 	unsigned int cstate;
-
-	cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) + 1;
+	bool uninitialized_var(tick);
+	int cpu = smp_processor_id();
 
 	/*
-	 * NB: if CPUIDLE_FLAG_TLB_FLUSHED is set, this idle transition
-	 * will probably flush the TLB.  It's not guaranteed to flush
-	 * the TLB, though, so it's not clear that we can do anything
-	 * useful with this knowledge.
+	 * leave_mm() to avoid costly and often unnecessary wakeups
+	 * for flushing the user TLB's associated with the active mm.
 	 */
-
-	if (!(lapic_timer_reliable_states & (1 << (cstate))))
-		tick_broadcast_enter();
+	if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
+		leave_mm(cpu);
+
+	if (!static_cpu_has(X86_FEATURE_ARAT)) {
+		cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) &
+				MWAIT_CSTATE_MASK) + 1;
+		tick = false;
+		if (!(lapic_timer_reliable_states & (1 << (cstate)))) {
+			tick = true;
+			tick_broadcast_enter();
+		}
+	}
 
 	mwait_idle_with_hints(eax, ecx);
 
-	if (!(lapic_timer_reliable_states & (1 << (cstate))))
+	if (!static_cpu_has(X86_FEATURE_ARAT) && tick)
 		tick_broadcast_exit();
 
 	return index;
@@ -1060,7 +1067,7 @@ static const struct idle_cpu idle_cpu_dnv = {
 };
 
 #define ICPU(model, cpu) \
-	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu }
+	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&cpu }
 
 static const struct x86_cpu_id intel_idle_ids[] __initconst = {
 	ICPU(INTEL_FAM6_NEHALEM_EP,		idle_cpu_nehalem),
@@ -1124,6 +1131,11 @@ static int __init intel_idle_probe(void)
 		return -ENODEV;
 	}
 
+	if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
+		pr_debug("Please enable MWAIT in BIOS SETUP\n");
+		return -ENODEV;
+	}
+
 	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
 		return -ENODEV;