[PATCH 4.4 25/63] x86/mm: Remove flush_tlb() and flush_tlb_current_task()

Greg Kroah-Hartman
2018-01-01T14:27:33Z

From: Andy Lutomirski <luto@kernel.org>

commit 29961b59a51f8c6838a26a45e871a7ed6771809b upstream.

I was trying to figure out what how flush_tlb_current_task() would
possibly work correctly if current->mm != current->active_mm, but I
realized I could spare myself the effort: it has no callers except
the unused flush_tlb() macro.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/e52d64c11690f85e9f1d69d7b48cc2269cd2e94b.1492844372.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/include/asm/tlbflush.h | 9 ---------
arch/x86/mm/tlb.c | 17 -----------------
2 files changed, 26 deletions(-)

--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -204,7 +204,6 @@ static inline void __flush_tlb_one(unsig
/*
* TLB flushing:
*
- * - flush_tlb() flushes the current mm struct TLBs
* - flush_tlb_all() flushes all processes TLBs
* - flush_tlb_mm(mm) flushes the specified mm context TLB's
* - flush_tlb_page(vma, vmaddr) flushes one page
@@ -236,11 +235,6 @@ static inline void flush_tlb_all(void)
__flush_tlb_all();
}

-static inline void flush_tlb(void)
-{
- __flush_tlb_up();
-}
-
static inline void local_flush_tlb(void)
{
__flush_tlb_up();
@@ -302,14 +296,11 @@ static inline void flush_tlb_kernel_rang
flush_tlb_mm_range(vma->vm_mm, start, end, vma->vm_flags)

extern void flush_tlb_all(void);
-extern void flush_tlb_current_task(void);
extern void flush_tlb_page(struct vm_area_struct *, unsigned long);
extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
unsigned long end, unsigned long vmflag);
extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);

-#define flush_tlb() flush_tlb_current_task()
-
void native_flush_tlb_others(const struct cpumask *cpumask,
struct mm_struct *mm,
unsigned long start, unsigned long end);
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -272,23 +272,6 @@ void native_flush_tlb_others(const struc
smp_call_function_many(cpumask, flush_tlb_func, &info, 1);
}

-void flush_tlb_current_task(void)
-{
- struct mm_struct *mm = current->mm;
-
- preempt_disable();
-
- count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
-
- /* This is an implicit full barrier that synchronizes with switch_mm. */
- 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);
- preempt_enable();
-}
-
/*
* See Documentation/x86/tlb.txt for details. We choose 33
* because it is large enough to cover the vast majority (at