[RESEND PATCH v4 8/9] arm64: entry.S: convert elX_irq

[James Morse]

Following our 'dai' order, irqs should be processed with debug and
serror exceptions unmasked.

Add a helper to unmask these two, (and fiq for good measure).

Signed-off-by: James Morse <james.morse at arm.com>
Reviewed-by: Julien Thierry <julien.thierry at arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>

==
Changes since v3:
* Added comment against enable_da_f
---
 arch/arm64/include/asm/assembler.h | 5 +++++
 arch/arm64/kernel/entry.S          | 4 ++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index c2a37e2f733c..e4ac505b7b3d 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -54,6 +54,11 @@
 	msr	daif, \tmp
 	.endm
 
+	/* IRQ is the lowest priority flag, unconditionally unmask the rest. */
+	.macro enable_da_f
+	msr	daifclr, #(8 | 4 | 1)
+	.endm
+
 /*
  * Enable and disable interrupts.
  */
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index f7dfe5d2b1fb..df085ec003b0 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -557,7 +557,7 @@ ENDPROC(el1_sync)
 	.align	6
 el1_irq:
 	kernel_entry 1
-	enable_dbg
+	enable_da_f
 #ifdef CONFIG_TRACE_IRQFLAGS
 	bl	trace_hardirqs_off
 #endif
@@ -766,7 +766,7 @@ ENDPROC(el0_sync)
 el0_irq:
 	kernel_entry 0
 el0_irq_naked:
-	enable_dbg
+	enable_da_f
 #ifdef CONFIG_TRACE_IRQFLAGS
 	bl	trace_hardirqs_off
 #endif
-- 
2.15.0.rc2