linux-kernel - [RFC 10/13] x86/mm: Factor out remote TLB flushing

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Date:	Fri,  8 Jan 2016 15:15:28 -0800
From:	Andy Lutomirski <luto@...nel.org>
To:	x86@...nel.org, linux-kernel@...r.kernel.org
Cc:	Borislav Petkov <bp@...en8.de>, Brian Gerst <brgerst@...il.com>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Oleg Nesterov <oleg@...hat.com>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	Andy Lutomirski <luto@...nel.org>
Subject: [RFC 10/13] x86/mm: Factor out remote TLB flushing

There are three call sites that propagate TLB flushes, and they all
do exactly the same thing.  Factor the code out into a helper.

Signed-off-by: Andy Lutomirski <luto@...nel.org>
---
 arch/x86/mm/tlb.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 8f4cc3dfac32..b208a33571b0 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -154,6 +154,14 @@ void native_flush_tlb_others(const struct cpumask *cpumask,
 	smp_call_function_many(cpumask, flush_tlb_func, &info, 1);
 }
 
+static void propagate_tlb_flush(unsigned int this_cpu,
+				struct mm_struct *mm, unsigned long start,
+				unsigned long end)
+{
+	if (cpumask_any_but(mm_cpumask(mm), this_cpu) < nr_cpu_ids)
+		flush_tlb_others(mm_cpumask(mm), mm, 0UL, TLB_FLUSH_ALL);
+}
+
 void flush_tlb_current_task(void)
 {
 	struct mm_struct *mm = current->mm;
@@ -166,8 +174,7 @@ void flush_tlb_current_task(void)
 	local_flush_tlb();
 
 	trace_tlb_flush(TLB_LOCAL_SHOOTDOWN, TLB_FLUSH_ALL);
-	if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
-		flush_tlb_others(mm_cpumask(mm), mm, 0UL, TLB_FLUSH_ALL);
+	propagate_tlb_flush(smp_processor_id(), mm, 0UL, TLB_FLUSH_ALL);
 	preempt_enable();
 }
 
@@ -231,8 +238,7 @@ out:
 		start = 0UL;
 		end = TLB_FLUSH_ALL;
 	}
-	if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
-		flush_tlb_others(mm_cpumask(mm), mm, start, end);
+	propagate_tlb_flush(smp_processor_id(), mm, start, end);
 	preempt_enable();
 }
 
@@ -257,8 +263,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long start)
 		}
 	}
 
-	if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
-		flush_tlb_others(mm_cpumask(mm), mm, start, 0UL);
+	propagate_tlb_flush(smp_processor_id(), mm, start, 0UL);
 
 	preempt_enable();
 }
-- 
2.5.0