arm64: Remove unused daif related functions/macros

hulk inclusion
category: feature
bugzilla: 9291
CVE: NA

ported from https://lore.kernel.org/patchwork/patch/1037466/

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

There are some helpers to modify PSR.[DAIF] bits that are not referenced
anywhere. The less these bits are available outside of local_irq_*
functions the better.

Get rid of those unused helpers.
Signed-off-by: NJulien Thierry <julien.thierry@arm.com>
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: NWei Li <liwei391@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/arm64/include/asm/assembler.h

@@ -60,16 +60,8 @@
 	.endm
 
 /*
- * Enable and disable interrupts.
+ * Save/restore interrupts.
  */
-	.macro	disable_irq
-	msr	daifset, #2
-	.endm
-
-	.macro	enable_irq
-	msr	daifclr, #2
-	.endm
-
 	.macro	save_and_disable_irq, flags
 	mrs	\flags, daif
 	msr	daifset, #2

arch/arm64/include/asm/daifflags.h

@@ -46,16 +46,6 @@ static inline unsigned long local_daif_save(void)
 	return flags;
 }
 
-static inline void local_daif_unmask(void)
-{
-	trace_hardirqs_on();
-	asm volatile(
-		"msr	daifclr, #0xf		// local_daif_unmask"
-		:
-		:
-		: "memory");
-}
-
 static inline void local_daif_restore(unsigned long flags)
 {
 	if (!arch_irqs_disabled_flags(flags))