Commit c7e46327 authored by Ma Wupeng's avatar Ma Wupeng Committed by Wupeng Ma
Browse files

arm64: mm: Replace global variable in pbha with static key 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IA5L01



--------------------------------

During the lmbench test, it was observed that bw_mem experienced a
degradation of 8% or more. To solve this issue, replacing the global
variables with a static key.

Fixes: 0d65528c ("arm64: mm: Detect and enable PBHA bit0 at early startup")
Signed-off-by: default avatarMa Wupeng <mawupeng1@huawei.com>
parent a701c2bd

drivers/soc/hisilicon/pbha.c

+9 −8
Original line number Diff line number Diff line
@@ -17,8 +17,9 @@ 


#define HBM_MODE_CACHE	1



bool __ro_after_init pbha_bit0_enabled;

bool __ro_after_init pbha_bit0_kernel_enabled;

__ro_after_init DEFINE_STATIC_KEY_FALSE(pbha_bit0_enabled);

__ro_after_init DEFINE_STATIC_KEY_FALSE(pbha_bit0_kernel_enabled);



static bool pbha_enabled_phase_1;



void __init early_pbha_bit0_init(void)
@@ -191,15 +192,15 @@ static int __init setup_pbha(char *str) 
		return 0;



	if (strcmp(str, "enable") == 0) {

		pbha_bit0_enabled = true;

		pbha_bit0_kernel_enabled = true;

		static_branch_enable(&pbha_bit0_enabled);

		static_branch_enable(&pbha_bit0_kernel_enabled);

	} else if (strcmp(str, "user") == 0) {

		pbha_bit0_enabled = true;

		static_branch_enable(&pbha_bit0_enabled);

	}



	if (pbha_bit0_enabled)

		pr_info("pbha bit_0 enabled, kernel: %d\n",

			pbha_bit0_kernel_enabled);

	if (static_branch_likely(&pbha_bit0_enabled))

		pr_info("pbha bit_0 enabled, kernel: %ld\n",

			static_branch_likely(&pbha_bit0_kernel_enabled));



	return 0;

}

include/linux/pbha.h

+8 −5
Original line number Diff line number Diff line
@@ -20,20 +20,22 @@ 
#define HBM_MODE_CACHE	1



#ifdef CONFIG_ARM64_PBHA

extern bool __ro_after_init pbha_bit0_enabled;

extern bool __ro_after_init pbha_bit0_kernel_enabled;

DECLARE_STATIC_KEY_FALSE(pbha_bit0_enabled);

DECLARE_STATIC_KEY_FALSE(pbha_bit0_kernel_enabled);



extern struct mm_walk_ops pbha_bit0_walk_ops;

extern void __init early_pbha_bit0_init(void);

extern int pbha_bit0_update_vma(struct mm_struct *mm, int val);



static inline bool system_support_pbha_bit0(void)

{

	return pbha_bit0_enabled;

	return static_branch_unlikely(&pbha_bit0_enabled);

}



static inline pgprot_t pgprot_pbha_bit0(pgprot_t prot)

{

	if (!system_support_pbha_bit0() || !pbha_bit0_kernel_enabled)

	if (!system_support_pbha_bit0() ||

	    !static_branch_unlikely(&pbha_bit0_kernel_enabled))

		return prot;



	return pgprot_pbha(prot, PBHA_VAL_BIT0);
@@ -45,7 +47,8 @@ static inline pte_t maybe_mk_pbha_bit0(pte_t pte, struct vm_area_struct *vma) 
		return pte;



	/* global init task will update pbha bit0 iff kernel can do this */

	if (unlikely(is_global_init(current)) && pbha_bit0_kernel_enabled &&

	if (unlikely(is_global_init(current)) &&

	    static_branch_unlikely(&pbha_bit0_kernel_enabled) &&

	    !(vma->vm_flags & VM_PBHA_BIT0))

		vma->vm_flags |= VM_PBHA_BIT0;