From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Fri, 17 May 2013 17:54:37 +0100 Subject: [PATCH 1/2] ARM: tlb: don't perform inner-shareable invalidation for local TLB ops Message-ID: <1368809678-25818-1-git-send-email-will.deacon@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. This allows us to modify the v7 SMP TLB flags to include *both* inner-shareable and non-shareable operations and then check the relevant flags depending on whether the operation is local or not. 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 Reported-by: Albin Tonnerre Signed-off-by: Will Deacon --- arch/arm/include/asm/tlbflush.h | 67 ++++++++++++++++++++++++++++++++++++++--- arch/arm/kernel/smp_tlb.c | 8 ++--- arch/arm/mm/context.c | 6 +--- 3 files changed, 68 insertions(+), 13 deletions(-) diff --git a/arch/arm/include/asm/tlbflush.h b/arch/arm/include/asm/tlbflush.h index a3625d1..55b5e18 100644 --- a/arch/arm/include/asm/tlbflush.h +++ b/arch/arm/include/asm/tlbflush.h @@ -167,6 +167,8 @@ #endif #define v7wbi_tlb_flags_smp (TLB_WB | TLB_BARRIER | \ + TLB_V6_U_FULL | TLB_V6_U_PAGE | \ + TLB_V6_U_ASID | \ TLB_V7_UIS_FULL | TLB_V7_UIS_PAGE | \ TLB_V7_UIS_ASID | TLB_V7_UIS_BP) #define v7wbi_tlb_flags_up (TLB_WB | TLB_DCLEAN | TLB_BARRIER | \ @@ -330,6 +332,21 @@ static inline void local_flush_tlb_all(void) tlb_op(TLB_V4_U_FULL | TLB_V6_U_FULL, "c8, c7, 0", zero); tlb_op(TLB_V4_D_FULL | TLB_V6_D_FULL, "c8, c6, 0", zero); tlb_op(TLB_V4_I_FULL | TLB_V6_I_FULL, "c8, c5, 0", zero); + + if (tlb_flag(TLB_BARRIER)) { + dsb(); + isb(); + } +} + +static inline void __flush_tlb_all(void) +{ + const int zero = 0; + const unsigned int __tlb_flag = __cpu_tlb_flags; + + if (tlb_flag(TLB_WB)) + dsb(); + tlb_op(TLB_V7_UIS_FULL, "c8, c3, 0", zero); if (tlb_flag(TLB_BARRIER)) { @@ -348,21 +365,32 @@ static inline void local_flush_tlb_mm(struct mm_struct *mm) dsb(); if (possible_tlb_flags & (TLB_V4_U_FULL|TLB_V4_D_FULL|TLB_V4_I_FULL)) { - if (cpumask_test_cpu(get_cpu(), mm_cpumask(mm))) { + if (cpumask_test_cpu(smp_processor_id(), mm_cpumask(mm))) { tlb_op(TLB_V4_U_FULL, "c8, c7, 0", zero); tlb_op(TLB_V4_D_FULL, "c8, c6, 0", zero); tlb_op(TLB_V4_I_FULL, "c8, c5, 0", zero); } - put_cpu(); } tlb_op(TLB_V6_U_ASID, "c8, c7, 2", asid); tlb_op(TLB_V6_D_ASID, "c8, c6, 2", asid); tlb_op(TLB_V6_I_ASID, "c8, c5, 2", asid); + + if (tlb_flag(TLB_BARRIER)) + dsb(); +} + +static inline void __flush_tlb_mm(struct mm_struct *mm) +{ + const unsigned int __tlb_flag = __cpu_tlb_flags; + + if (tlb_flag(TLB_WB)) + dsb(); + #ifdef CONFIG_ARM_ERRATA_720789 - tlb_op(TLB_V7_UIS_ASID, "c8, c3, 0", zero); + tlb_op(TLB_V7_UIS_ASID, "c8, c3, 0", 0); #else - tlb_op(TLB_V7_UIS_ASID, "c8, c3, 2", asid); + tlb_op(TLB_V7_UIS_ASID, "c8, c3, 2", ASID(mm)); #endif if (tlb_flag(TLB_BARRIER)) @@ -392,6 +420,21 @@ local_flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr) tlb_op(TLB_V6_U_PAGE, "c8, c7, 1", uaddr); tlb_op(TLB_V6_D_PAGE, "c8, c6, 1", uaddr); tlb_op(TLB_V6_I_PAGE, "c8, c5, 1", uaddr); + + if (tlb_flag(TLB_BARRIER)) + dsb(); +} + +static inline void +__flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr) +{ + const unsigned int __tlb_flag = __cpu_tlb_flags; + + uaddr = (uaddr & PAGE_MASK) | ASID(vma->vm_mm); + + if (tlb_flag(TLB_WB)) + dsb(); + #ifdef CONFIG_ARM_ERRATA_720789 tlb_op(TLB_V7_UIS_PAGE, "c8, c3, 3", uaddr & PAGE_MASK); #else @@ -421,6 +464,22 @@ static inline void local_flush_tlb_kernel_page(unsigned long kaddr) tlb_op(TLB_V6_U_PAGE, "c8, c7, 1", kaddr); tlb_op(TLB_V6_D_PAGE, "c8, c6, 1", kaddr); tlb_op(TLB_V6_I_PAGE, "c8, c5, 1", kaddr); + + if (tlb_flag(TLB_BARRIER)) { + dsb(); + isb(); + } +} + +static inline void __flush_tlb_kernel_page(unsigned long kaddr) +{ + const unsigned int __tlb_flag = __cpu_tlb_flags; + + kaddr &= PAGE_MASK; + + if (tlb_flag(TLB_WB)) + dsb(); + tlb_op(TLB_V7_UIS_PAGE, "c8, c3, 1", kaddr); if (tlb_flag(TLB_BARRIER)) { diff --git a/arch/arm/kernel/smp_tlb.c b/arch/arm/kernel/smp_tlb.c index 9a52a07..cc299b5 100644 --- a/arch/arm/kernel/smp_tlb.c +++ b/arch/arm/kernel/smp_tlb.c @@ -135,7 +135,7 @@ void flush_tlb_all(void) if (tlb_ops_need_broadcast()) on_each_cpu(ipi_flush_tlb_all, NULL, 1); else - local_flush_tlb_all(); + __flush_tlb_all(); broadcast_tlb_a15_erratum(); } @@ -144,7 +144,7 @@ void flush_tlb_mm(struct mm_struct *mm) if (tlb_ops_need_broadcast()) on_each_cpu_mask(mm_cpumask(mm), ipi_flush_tlb_mm, mm, 1); else - local_flush_tlb_mm(mm); + __flush_tlb_mm(mm); broadcast_tlb_mm_a15_erratum(mm); } @@ -157,7 +157,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr) on_each_cpu_mask(mm_cpumask(vma->vm_mm), ipi_flush_tlb_page, &ta, 1); } else - local_flush_tlb_page(vma, uaddr); + __flush_tlb_page(vma, uaddr); broadcast_tlb_mm_a15_erratum(vma->vm_mm); } @@ -168,7 +168,7 @@ void flush_tlb_kernel_page(unsigned long kaddr) ta.ta_start = kaddr; on_each_cpu(ipi_flush_tlb_kernel_page, &ta, 1); } else - local_flush_tlb_kernel_page(kaddr); + __flush_tlb_kernel_page(kaddr); broadcast_tlb_a15_erratum(); } diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c index 2ac3737..62c1ec5 100644 --- a/arch/arm/mm/context.c +++ b/arch/arm/mm/context.c @@ -134,10 +134,7 @@ 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(); @@ -215,7 +212,6 @@ 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(); - dummy_flush_tlb_a15_erratum(); } atomic64_set(&per_cpu(active_asids, cpu), asid); -- 1.8.2.2