linux-kernel - [PATCH v5 16/27] arm64: daifflags: Include PMR in daifflags restore operations

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Date:   Tue, 28 Aug 2018 16:51:26 +0100
From:   Julien Thierry <julien.thierry@....com>
To:     linux-arm-kernel@...ts.infradead.org
Cc:     linux-kernel@...r.kernel.org, daniel.thompson@...aro.org,
        joel@...lfernandes.org, marc.zyngier@....com, mark.rutland@....com,
        christoffer.dall@....com, james.morse@....com,
        catalin.marinas@....com, will.deacon@....com,
        Julien Thierry <julien.thierry@....com>
Subject: [PATCH v5 16/27] arm64: daifflags: Include PMR in daifflags restore operations

The addition of PMR should not bypass the semantics of daifflags.

When DA_F are set, I bit is also set as no interrupts (even of higher
priority) is allowed.

When DA_F are cleared, I bit is cleared and interrupt enabling/disabling
goes through ICC_PMR_EL1.

Signed-off-by: Julien Thierry <julien.thierry@....com>
Cc: Catalin Marinas <catalin.marinas@....com>
Cc: Will Deacon <will.deacon@....com>
Cc: James Morse <james.morse@....com>
---
 arch/arm64/include/asm/daifflags.h | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/daifflags.h b/arch/arm64/include/asm/daifflags.h
index 8d91f22..ccd95e8 100644
--- a/arch/arm64/include/asm/daifflags.h
+++ b/arch/arm64/include/asm/daifflags.h
@@ -18,8 +18,14 @@
 
 #include <linux/irqflags.h>
 
-#define DAIF_PROCCTX		0
-#define DAIF_PROCCTX_NOIRQ	PSR_I_BIT
+#include <asm/arch_gicv3.h>
+
+#define DAIF_PROCCTX	MAKE_ARCH_FLAGS(0, ICC_PMR_EL1_UNMASKED)
+
+#define DAIF_PROCCTX_NOIRQ						\
+	(gic_prio_masking_enabled() ?					\
+		MAKE_ARCH_FLAGS(0, ICC_PMR_EL1_MASKED) :		\
+		MAKE_ARCH_FLAGS(PSR_I_BIT, ICC_PMR_EL1_UNMASKED))
 
 /* mask/save/unmask/restore all exceptions, including interrupts. */
 static inline void local_daif_mask(void)
@@ -51,6 +57,10 @@ static inline void local_daif_unmask(void)
 		:
 		:
 		: "memory");
+
+	/* Unmask IRQs in PMR if needed */
+	if (gic_prio_masking_enabled())
+		arch_local_irq_enable();
 }
 
 static inline void local_daif_restore(unsigned long flags)
-- 
1.9.1