[PATCH v2 1/7] mm: remove arch_flush_lazy_mmu_mode()

Kevin Brodsky
2025-09-08T07:40:42Z

This function has only ever been used in arch/x86, so there is no
need for other architectures to implement it. Remove it from
linux/pgtable.h and all architectures besides x86.

The arm64 implementation is not empty but it is only called from
arch_leave_lazy_mmu_mode(), so we can simply fold it there.

Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
---
arch/arm64/include/asm/pgtable.h | 9 +--------
arch/powerpc/include/asm/book3s/64/tlbflush-hash.h | 2 --
arch/sparc/include/asm/tlbflush_64.h | 1 -
arch/x86/include/asm/pgtable.h | 3 ++-
include/linux/pgtable.h | 1 -
5 files changed, 3 insertions(+), 13 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index abd2dee416b3..728d7b6ed20a 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -101,21 +101,14 @@ static inline void arch_enter_lazy_mmu_mode(void)
set_thread_flag(TIF_LAZY_MMU);
}

-static inline void arch_flush_lazy_mmu_mode(void)
+static inline void arch_leave_lazy_mmu_mode(void)
{
if (in_interrupt())
return;

if (test_and_clear_thread_flag(TIF_LAZY_MMU_PENDING))
emit_pte_barriers();
-}
-
-static inline void arch_leave_lazy_mmu_mode(void)
-{
- if (in_interrupt())
- return;

- arch_flush_lazy_mmu_mode();
clear_thread_flag(TIF_LAZY_MMU);
}

diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
index 146287d9580f..176d7fd79eeb 100644
--- a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
+++ b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
@@ -55,8 +55,6 @@ static inline void arch_leave_lazy_mmu_mode(void)
preempt_enable();
}

-#define arch_flush_lazy_mmu_mode() do {} while (0)
-
extern void hash__tlbiel_all(unsigned int action);

extern void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize,
diff --git a/arch/sparc/include/asm/tlbflush_64.h b/arch/sparc/include/asm/tlbflush_64.h
index 8b8cdaa69272..cd144eb31bdd 100644
--- a/arch/sparc/include/asm/tlbflush_64.h
+++ b/arch/sparc/include/asm/tlbflush_64.h
@@ -44,7 +44,6 @@ void flush_tlb_kernel_range(unsigned long start, unsigned long end);
void flush_tlb_pending(void);
void arch_enter_lazy_mmu_mode(void);
void arch_leave_lazy_mmu_mode(void);
-#define arch_flush_lazy_mmu_mode() do {} while (0)

/* Local cpu only. */
void __flush_tlb_all(void);
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index e33df3da6980..14fd672bc9b2 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -117,7 +117,8 @@ extern pmdval_t early_pmd_flags;
#define pte_val(x) native_pte_val(x)
#define __pte(x) native_make_pte(x)

-#define arch_end_context_switch(prev) do {} while(0)
+#define arch_end_context_switch(prev) do {} while (0)
+#define arch_flush_lazy_mmu_mode() do {} while (0)
#endif /* CONFIG_PARAVIRT_XXL */

static inline pmd_t pmd_set_flags(pmd_t pmd, pmdval_t set)
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 94249e671a7e..8d6007123cdf 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -234,7 +234,6 @@ static inline int pmd_dirty(pmd_t pmd)
#ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
#define arch_enter_lazy_mmu_mode() do {} while (0)
#define arch_leave_lazy_mmu_mode() do {} while (0)
-#define arch_flush_lazy_mmu_mode() do {} while (0)
#endif

#ifndef pte_batch_hint
--
2.47.0