Commit 4dd9b4d7 authored Dec 15, 2025 by Kevin Brodsky Committed by Andrew Morton Jan 20, 2026

arm64: mm: replace TIF_LAZY_MMU with is_lazy_mmu_mode_active()

The generic lazy_mmu layer now tracks whether a task is in lazy MMU mode. 
As a result we no longer need a TIF flag for that purpose - let's use the
new is_lazy_mmu_mode_active() helper instead.

The explicit check for in_interrupt() is no longer necessary either as
is_lazy_mmu_mode_active() always returns false in interrupt context.

Link: https://lkml.kernel.org/r/20251215150323.2218608-11-kevin.brodsky@arm.com


Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David Hildenbrand <david@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Juegren Gross <jgross@suse.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

parent 5ab24674

arch/arm64/include/asm/pgtable.h

+3 −16

Original line number	Diff line number	Diff line
		@@ -62,28 +62,16 @@ static inline void emit_pte_barriers(void)

		static inline void queue_pte_barriers(void)
		{
		unsigned long flags;

		if (in_interrupt()) {
		emit_pte_barriers();
		return;
		}

		flags = read_thread_flags();

		if (flags & BIT(TIF_LAZY_MMU)) {
		if (is_lazy_mmu_mode_active()) {
		/* Avoid the atomic op if already set. */
		if (!(flags & BIT(TIF_LAZY_MMU_PENDING)))
		if (!test_thread_flag(TIF_LAZY_MMU_PENDING))
		set_thread_flag(TIF_LAZY_MMU_PENDING);
		} else {
		emit_pte_barriers();
		}
		}

		static inline void arch_enter_lazy_mmu_mode(void)
		{
		set_thread_flag(TIF_LAZY_MMU);
		}
		static inline void arch_enter_lazy_mmu_mode(void) {}

		static inline void arch_flush_lazy_mmu_mode(void)
		{
		@@ -94,7 +82,6 @@ static inline void arch_flush_lazy_mmu_mode(void)
		static inline void arch_leave_lazy_mmu_mode(void)
		{
		arch_flush_lazy_mmu_mode();
		clear_thread_flag(TIF_LAZY_MMU);
		}

		#ifdef CONFIG_TRANSPARENT_HUGEPAGE

arch/arm64/include/asm/thread_info.h

+1 −2

Original line number	Diff line number	Diff line
		@@ -84,8 +84,7 @@ void arch_setup_new_exec(void);
		#define TIF_SME_VL_INHERIT 28 /* Inherit SME vl_onexec across exec */
		#define TIF_KERNEL_FPSTATE 29 /* Task is in a kernel mode FPSIMD section */
		#define TIF_TSC_SIGSEGV 30 /* SIGSEGV on counter-timer access */
		#define TIF_LAZY_MMU 31 /* Task in lazy mmu mode */
		#define TIF_LAZY_MMU_PENDING 32 /* Ops pending for lazy mmu mode exit */
		#define TIF_LAZY_MMU_PENDING 31 /* Ops pending for lazy mmu mode exit */

		#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
		#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)