[PATCH v4 08/12] arm64: mm: replace TIF_LAZY_MMU with in_lazy_mmu_mode()

[Kevin Brodsky]

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 in_lazy_mmu_mode() helper instead.

Signed-off-by: Kevin Brodsky <kevin.brodsky at arm.com>
---
 arch/arm64/include/asm/pgtable.h     | 16 +++-------------
 arch/arm64/include/asm/thread_info.h |  3 +--
 2 files changed, 4 insertions(+), 15 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 535435248923..61ca88f94551 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -62,30 +62,21 @@ 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)) {
-		/* Avoid the atomic op if already set. */
-		if (!(flags & BIT(TIF_LAZY_MMU_PENDING)))
-			set_thread_flag(TIF_LAZY_MMU_PENDING);
-	} else {
+	if (in_lazy_mmu_mode())
+		test_and_set_thread_flag(TIF_LAZY_MMU_PENDING);
+	else
 		emit_pte_barriers();
-	}
 }
 
 static inline void arch_enter_lazy_mmu_mode(void)
 {
 	if (in_interrupt())
 		return;
-
-	set_thread_flag(TIF_LAZY_MMU);
 }
 
 static inline void arch_flush_lazy_mmu_mode(void)
@@ -103,7 +94,6 @@ static inline void arch_leave_lazy_mmu_mode(void)
 		return;
 
 	arch_flush_lazy_mmu_mode();
-	clear_thread_flag(TIF_LAZY_MMU);
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index f241b8601ebd..4ff8da0767d9 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -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)
-- 
2.47.0