ARM: tlb: don't perform inner-shareable invalidation for local TLB ops

Inner-shareable TLB invalidation is typically more expensive than local
(non-shareable) invalidation, so performing the broadcasting for
local_flush_tlb_* operations is a waste of cycles and needlessly
clobbers entries in the TLBs of other CPUs.

This patch introduces __flush_tlb_* versions for many of the TLB
invalidation functions, which only respect inner-shareable variants of
the invalidation instructions when presented with the TLB_V7_UIS_FULL
flag. The local version is also inlined to prevent SMP_ON_UP kernels
from missing flushes, where the __flush variant would be called with
the UP flags.

This gains us around 0.5% in hackbench scores for a dual-core A15, but I
would expect this to improve as more cores (and clusters) are added to
the equation.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Albin Tonnerre <Albin.Tonnerre@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 1 insertions, 6 deletions

diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index 4a0544492f10..84e6f772e204 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -162,10 +162,7 @@ static void flush_context(unsigned int cpu)
         }
 
         /* Queue a TLB invalidate and flush the I-cache if necessary. */
-        if (!tlb_ops_need_broadcast())
-                cpumask_set_cpu(cpu, &tlb_flush_pending);
-        else
-                cpumask_setall(&tlb_flush_pending);
+        cpumask_setall(&tlb_flush_pending);
 
         if (icache_is_vivt_asid_tagged())
                 __flush_icache_all();
@@ -245,8 +242,6 @@ void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk)
         if (cpumask_test_and_clear_cpu(cpu, &tlb_flush_pending)) {
                 local_flush_bp_all();
                 local_flush_tlb_all();
-                if (erratum_a15_798181())
-                        dummy_flush_tlb_a15_erratum();
         }
 
         atomic64_set(&per_cpu(active_asids, cpu), asid);