[PATCH v3 7/8] irqchip/gic-v3: Improve the maintainability of NMI masking in GIC driver

[Liao Chang]

It has a better maintainability to use the local_nmi_enable() in GIC
driver to unmask NMI and keep regular IRQ and FIQ maskable, instead of
writing raw value into DAIF, PMR and ALLINT directly.

Signed-off-by: Liao Chang <liaochang1 at huawei.com>
---
 arch/arm64/include/asm/daifflags.h | 13 +++++++++++++
 drivers/irqchip/irq-gic-v3.c       |  6 ++----
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/daifflags.h b/arch/arm64/include/asm/daifflags.h
index b831def08bb3..1196eb85aa8d 100644
--- a/arch/arm64/include/asm/daifflags.h
+++ b/arch/arm64/include/asm/daifflags.h
@@ -330,4 +330,17 @@ static inline void local_errnmi_enable(void)
 	irqflags.fields.allint = 0;
 	local_allint_restore(irqflags);
 }
+
+/*
+ * local_nmi_enable - Enable NMI with or without superpriority.
+ */
+static inline void local_nmi_enable(void)
+{
+	arch_irqflags_t irqflags;
+
+	irqflags.fields.daif = read_sysreg(daif);
+	irqflags.fields.pmr = GIC_PRIO_IRQOFF;
+	irqflags.fields.allint = 0;
+	local_allint_restore(irqflags);
+}
 #endif
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 6fb276504bcc..ed7d8d87768f 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -33,6 +33,7 @@
 #include <asm/exception.h>
 #include <asm/smp_plat.h>
 #include <asm/virt.h>
+#include <asm/daifflags.h>
 
 #include "irq-gic-common.h"
 
@@ -813,10 +814,7 @@ static void __gic_handle_irq_from_irqson(struct pt_regs *regs)
 		nmi_exit();
 	}
 
-	if (gic_prio_masking_enabled()) {
-		gic_pmr_mask_irqs();
-		gic_arch_enable_irqs();
-	}
+	local_nmi_enable();
 
 	if (!is_nmi)
 		__gic_handle_irq(irqnr, regs);
-- 
2.34.1