Commit f0915781 authored by Will Deacon's avatar Will Deacon
Browse files

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: default avatarCatalin Marinas <catalin.marinas@arm.com>
Reported-by: default avatarAlbin Tonnerre <Albin.Tonnerre@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 792a843a

arch/arm/include/asm/tlbflush.h

+118 −20
Original line number Diff line number Diff line
@@ -319,6 +319,16 @@ extern struct cpu_tlb_fns cpu_tlb; 
#define tlb_op(f, regs, arg)	__tlb_op(f, "p15, 0, %0, " regs, arg)

#define tlb_l2_op(f, regs, arg)	__tlb_op(f, "p15, 1, %0, " regs, arg)



static inline void __local_flush_tlb_all(void)

{

	const int zero = 0;

	const unsigned int __tlb_flag = __cpu_tlb_flags;



	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);

}



static inline void local_flush_tlb_all(void)

{

	const int zero = 0;
@@ -327,10 +337,8 @@ static inline void local_flush_tlb_all(void) 
	if (tlb_flag(TLB_WB))

		dsb();



	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);

	tlb_op(TLB_V7_UIS_FULL, "c8, c3, 0", zero);

	__local_flush_tlb_all();

	tlb_op(TLB_V7_UIS_FULL, "c8, c7, 0", zero);



	if (tlb_flag(TLB_BARRIER)) {

		dsb();
@@ -338,31 +346,69 @@ static inline void local_flush_tlb_all(void) 
	}

}



static inline void local_flush_tlb_mm(struct mm_struct *mm)

static inline void __flush_tlb_all(void)

{

	const int zero = 0;

	const int asid = ASID(mm);

	const unsigned int __tlb_flag = __cpu_tlb_flags;



	if (tlb_flag(TLB_WB))

		dsb();



	__local_flush_tlb_all();

	tlb_op(TLB_V7_UIS_FULL, "c8, c3, 0", zero);



	if (tlb_flag(TLB_BARRIER)) {

		dsb();

		isb();

	}

}



static inline void __local_flush_tlb_mm(struct mm_struct *mm)

{

	const int zero = 0;

	const int asid = ASID(mm);

	const unsigned int __tlb_flag = __cpu_tlb_flags;



	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);

}



static inline void local_flush_tlb_mm(struct mm_struct *mm)

{

	const int asid = ASID(mm);

	const unsigned int __tlb_flag = __cpu_tlb_flags;



	if (tlb_flag(TLB_WB))

		dsb();



	__local_flush_tlb_mm(mm);

	tlb_op(TLB_V7_UIS_ASID, "c8, c7, 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();



	__local_flush_tlb_mm(mm);

#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))
@@ -370,16 +416,13 @@ static inline void local_flush_tlb_mm(struct mm_struct *mm) 
}



static inline void

local_flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)

__local_flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)

{

	const int zero = 0;

	const unsigned int __tlb_flag = __cpu_tlb_flags;



	uaddr = (uaddr & PAGE_MASK) | ASID(vma->vm_mm);



	if (tlb_flag(TLB_WB))

		dsb();



	if (possible_tlb_flags & (TLB_V4_U_PAGE|TLB_V4_D_PAGE|TLB_V4_I_PAGE|TLB_V4_I_FULL) &&

	    cpumask_test_cpu(smp_processor_id(), mm_cpumask(vma->vm_mm))) {

		tlb_op(TLB_V4_U_PAGE, "c8, c7, 1", uaddr);
@@ -392,6 +435,36 @@ 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);

}



static inline void

local_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();



	__local_flush_tlb_page(vma, uaddr);

	tlb_op(TLB_V7_UIS_PAGE, "c8, c7, 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();



	__local_flush_tlb_page(vma, uaddr);

#ifdef CONFIG_ARM_ERRATA_720789

	tlb_op(TLB_V7_UIS_PAGE, "c8, c3, 3", uaddr & PAGE_MASK);

#else
@@ -402,16 +475,11 @@ local_flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr) 
		dsb();

}



static inline void local_flush_tlb_kernel_page(unsigned long kaddr)

static inline void __local_flush_tlb_kernel_page(unsigned long kaddr)

{

	const int zero = 0;

	const unsigned int __tlb_flag = __cpu_tlb_flags;



	kaddr &= PAGE_MASK;



	if (tlb_flag(TLB_WB))

		dsb();



	tlb_op(TLB_V4_U_PAGE, "c8, c7, 1", kaddr);

	tlb_op(TLB_V4_D_PAGE, "c8, c6, 1", kaddr);

	tlb_op(TLB_V4_I_PAGE, "c8, c5, 1", kaddr);
@@ -421,6 +489,36 @@ 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);

}



static inline void local_flush_tlb_kernel_page(unsigned long kaddr)

{

	const unsigned int __tlb_flag = __cpu_tlb_flags;



	kaddr &= PAGE_MASK;



	if (tlb_flag(TLB_WB))

		dsb();



	__local_flush_tlb_kernel_page(kaddr);

	tlb_op(TLB_V7_UIS_PAGE, "c8, c7, 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();



	__local_flush_tlb_kernel_page(kaddr);

	tlb_op(TLB_V7_UIS_PAGE, "c8, c3, 1", kaddr);



	if (tlb_flag(TLB_BARRIER)) {

arch/arm/kernel/smp_tlb.c

+4 −4
Original line number Diff line number Diff line
@@ -104,7 +104,7 @@ 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();

}
@@ -113,7 +113,7 @@ 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);

}
@@ -126,7 +126,7 @@ 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);

}
@@ -137,7 +137,7 @@ 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();

}

arch/arm/mm/context.c

+1 −6
Original line number Diff line number Diff line
@@ -162,9 +162,6 @@ 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);



	if (icache_is_vivt_asid_tagged())
@@ -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);

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