From 67741ba3ba006558ac3541488c1db9dff9507e73 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Sat, 2 Feb 2019 01:43:18 +0000 Subject: [PATCH] MIPS: mm: Avoid HTW stop/start when dropping an inactive mm If drop_mmu_context() is called with an mm that is not currently active on the local CPU then there's no need for us to stop & start a hardware page table walker because it can't be fetching entries for the ASID corresponding to the mm we're operating on. Move the htw_stop() & htw_start() calls into the block which we run only if the mm is currently active, in order to avoid the redundant work. Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org --- arch/mips/include/asm/mmu_context.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h index 0d050d781737..5d0a73a5cf40 100644 --- a/arch/mips/include/asm/mmu_context.h +++ b/arch/mips/include/asm/mmu_context.h @@ -184,17 +184,18 @@ drop_mmu_context(struct mm_struct *mm) unsigned int cpu; local_irq_save(flags); - htw_stop(); cpu = smp_processor_id(); if (cpumask_test_cpu(cpu, mm_cpumask(mm))) { + htw_stop(); get_new_mmu_context(mm); write_c0_entryhi(cpu_asid(cpu, mm)); + htw_start(); } else { /* will get a new context next time */ cpu_context(cpu, mm) = 0; } - htw_start(); + local_irq_restore(flags); }