[PATCH v6 05/24] irqchip/gic-v3: Switch to PMR masking before calling IRQ handler
From: Julien Thierry
Date: Mon Nov 12 2018 - 06:59:57 EST
Mask the IRQ priority through PMR and re-enable IRQs at CPU level,
allowing only higher priority interrupts to be received during interrupt
handling.
Signed-off-by: Julien Thierry <julien.thierry@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Jason Cooper <jason@xxxxxxxxxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
---
arch/arm/include/asm/arch_gicv3.h | 17 +++++++++++++++++
arch/arm64/include/asm/arch_gicv3.h | 17 +++++++++++++++++
drivers/irqchip/irq-gic-v3.c | 10 ++++++++++
3 files changed, 44 insertions(+)
diff --git a/arch/arm/include/asm/arch_gicv3.h b/arch/arm/include/asm/arch_gicv3.h
index bef0b5d..f6f485f 100644
--- a/arch/arm/include/asm/arch_gicv3.h
+++ b/arch/arm/include/asm/arch_gicv3.h
@@ -363,5 +363,22 @@ static inline void gits_write_vpendbaser(u64 val, void * __iomem addr)
#define gits_read_vpendbaser(c) __gic_readq_nonatomic(c)
+static inline bool gic_prio_masking_enabled(void)
+{
+ return false;
+}
+
+static inline void gic_pmr_mask_irqs(void)
+{
+ /* Should not get called. */
+ WARN_ON_ONCE(true);
+}
+
+static inline void gic_arch_enable_irqs(void)
+{
+ /* Should not get called. */
+ WARN_ON_ONCE(true);
+}
+
#endif /* !__ASSEMBLY__ */
#endif /* !__ASM_ARCH_GICV3_H */
diff --git a/arch/arm64/include/asm/arch_gicv3.h b/arch/arm64/include/asm/arch_gicv3.h
index 37193e2..3f8d5f4 100644
--- a/arch/arm64/include/asm/arch_gicv3.h
+++ b/arch/arm64/include/asm/arch_gicv3.h
@@ -155,5 +155,22 @@ static inline u32 gic_read_rpr(void)
#define gits_write_vpendbaser(v, c) writeq_relaxed(v, c)
#define gits_read_vpendbaser(c) readq_relaxed(c)
+static inline bool gic_prio_masking_enabled(void)
+{
+ return system_supports_irq_prio_masking();
+}
+
+static inline void gic_pmr_mask_irqs(void)
+{
+ /* Should not get called yet. */
+ WARN_ON_ONCE(true);
+}
+
+static inline void gic_arch_enable_irqs(void)
+{
+ /* Should not get called yet. */
+ WARN_ON_ONCE(true);
+}
+
#endif /* __ASSEMBLY__ */
#endif /* __ASM_ARCH_GICV3_H */
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 8f87f40..e5d8c14 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -353,6 +353,11 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs
if (likely(irqnr > 15 && irqnr < 1020) || irqnr >= 8192) {
int err;
+ if (gic_prio_masking_enabled()) {
+ gic_pmr_mask_irqs();
+ gic_arch_enable_irqs();
+ }
+
if (static_branch_likely(&supports_deactivate_key))
gic_write_eoir(irqnr);
else
@@ -371,6 +376,11 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs
return;
}
if (irqnr < 16) {
+ if (gic_prio_masking_enabled()) {
+ gic_pmr_mask_irqs();
+ gic_arch_enable_irqs();
+ }
+
gic_write_eoir(irqnr);
if (static_branch_likely(&supports_deactivate_key))
gic_write_dir(irqnr);
--
1.9.1