Subject: [PATCH v5 04/11] powerpc/mce_power: Applies counting method to monitor lockless pgtbl walks

From: Leonardo Bras <[email-masked]>
Date: Wed, 2 Oct 2019 22:33:18 -0300

Applies the counting-based method for monitoring lockless pgtable walks on
addr_to_pfn().

local_irq_{save,restore} is already inside {begin,end}_lockless_pgtbl_walk,
so there is no need to repeat it here.

Signed-off-by: Leonardo Bras <[email-masked]>
---
 arch/powerpc/kernel/mce_power.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c
index 1cbf7f1a4e3d..7f888fb6f65c 100644
--- a/arch/powerpc/kernel/mce_power.c
+++ b/arch/powerpc/kernel/mce_power.c
@@ -29,7 +29,7 @@ unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr)
 {
 	pte_t *ptep;
 	unsigned int shift;
-	unsigned long pfn, flags;
+	unsigned long pfn, irq_mask;
 	struct mm_struct *mm;
 
 	if (user_mode(regs))
@@ -37,7 +37,7 @@ unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr)
 	else
 		mm = &init_mm;
 
-	local_irq_save(flags);
+	irq_mask = begin_lockless_pgtbl_walk(mm);
 	ptep = __find_linux_pte(mm->pgd, addr, NULL, &shift);
 
 	if (!ptep || pte_special(*ptep)) {
@@ -53,7 +53,7 @@ unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr)
 	}
 
 out:
-	local_irq_restore(flags);
+	end_lockless_pgtbl_walk(mm, irq_mask);
 	return pfn;
 }
 
-- 
2.20.1