1 files changed, 91 insertions, 72 deletions

diff --git a/arch/arm64/include/asm/irqflags.h b/arch/arm64/include/asm/irqflags.h
index 8c581281fa12..b57b9b1e4344 100644
--- a/arch/arm64/include/asm/irqflags.h
+++ b/arch/arm64/include/asm/irqflags.h
@@ -1,114 +1,133 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #ifndef __ASM_IRQFLAGS_H
 #define __ASM_IRQFLAGS_H
 
-#ifdef __KERNEL__
-
+#include <asm/alternative.h>
+#include <asm/barrier.h>
 #include <asm/ptrace.h>
+#include <asm/sysreg.h>
 
 /*
- * CPU interrupt mask handling.
+ * Aarch64 has flags for masking: Debug, Asynchronous (serror), Interrupts and
+ * FIQ exceptions, in the 'daif' register. We mask and unmask them in 'daif'
+ * order:
+ * Masking debug exceptions causes all other exceptions to be masked too/
+ * Masking SError masks IRQ/FIQ, but not debug exceptions. IRQ and FIQ are
+ * always masked and unmasked together, and have no side effects for other
+ * flags. Keeping to this order makes it easier for entry.S to know which
+ * exceptions should be unmasked.
  */
-static inline unsigned long arch_local_irq_save(void)
-{
-	unsigned long flags;
-	asm volatile(
-		"mrs	%0, daif		// arch_local_irq_save\n"
-		"msr	daifset, #2"
-		: "=r" (flags)
-		:
-		: "memory");
-	return flags;
-}
 
+/*
+ * CPU interrupt mask handling.
+ */
 static inline void arch_local_irq_enable(void)
 {
-	asm volatile(
-		"msr	daifclr, #2		// arch_local_irq_enable"
-		:
+	if (system_has_prio_mask_debugging()) {
+		u32 pmr = read_sysreg_s(SYS_ICC_PMR_EL1);
+
+		WARN_ON_ONCE(pmr != GIC_PRIO_IRQON && pmr != GIC_PRIO_IRQOFF);
+	}
+
+	asm volatile(ALTERNATIVE(
+		"msr	daifclr, #3		// arch_local_irq_enable",
+		__msr_s(SYS_ICC_PMR_EL1, "%0"),
+		ARM64_HAS_IRQ_PRIO_MASKING)
 		:
+		: "r" ((unsigned long) GIC_PRIO_IRQON)
 		: "memory");
+
+	pmr_sync();
 }
 
 static inline void arch_local_irq_disable(void)
 {
-	asm volatile(
-		"msr	daifset, #2		// arch_local_irq_disable"
-		:
+	if (system_has_prio_mask_debugging()) {
+		u32 pmr = read_sysreg_s(SYS_ICC_PMR_EL1);
+
+		WARN_ON_ONCE(pmr != GIC_PRIO_IRQON && pmr != GIC_PRIO_IRQOFF);
+	}
+
+	asm volatile(ALTERNATIVE(
+		"msr	daifset, #3		// arch_local_irq_disable",
+		__msr_s(SYS_ICC_PMR_EL1, "%0"),
+		ARM64_HAS_IRQ_PRIO_MASKING)
 		:
+		: "r" ((unsigned long) GIC_PRIO_IRQOFF)
 		: "memory");
 }
 
-#define local_fiq_enable()	asm("msr	daifclr, #1" : : : "memory")
-#define local_fiq_disable()	asm("msr	daifset, #1" : : : "memory")
-
-#define local_async_enable()	asm("msr	daifclr, #4" : : : "memory")
-#define local_async_disable()	asm("msr	daifset, #4" : : : "memory")
-
 /*
  * Save the current interrupt enable state.
  */
 static inline unsigned long arch_local_save_flags(void)
 {
 	unsigned long flags;
-	asm volatile(
-		"mrs	%0, daif		// arch_local_save_flags"
-		: "=r" (flags)
+
+	asm volatile(ALTERNATIVE(
+		"mrs	%0, daif",
+		__mrs_s("%0", SYS_ICC_PMR_EL1),
+		ARM64_HAS_IRQ_PRIO_MASKING)
+		: "=&r" (flags)
 		:
 		: "memory");
+
 	return flags;
 }
 
-/*
- * restore saved IRQ state
- */
-static inline void arch_local_irq_restore(unsigned long flags)
+static inline int arch_irqs_disabled_flags(unsigned long flags)
+{
+	int res;
+
+	asm volatile(ALTERNATIVE(
+		"and	%w0, %w1, #" __stringify(PSR_I_BIT),
+		"eor	%w0, %w1, #" __stringify(GIC_PRIO_IRQON),
+		ARM64_HAS_IRQ_PRIO_MASKING)
+		: "=&r" (res)
+		: "r" ((int) flags)
+		: "memory");
+
+	return res;
+}
+
+static inline int arch_irqs_disabled(void)
 {
-	asm volatile(
-		"msr	daif, %0		// arch_local_irq_restore"
-	:
-	: "r" (flags)
-	: "memory");
+	return arch_irqs_disabled_flags(arch_local_save_flags());
 }
 
-static inline int arch_irqs_disabled_flags(unsigned long flags)
+static inline unsigned long arch_local_irq_save(void)
 {
-	return flags & PSR_I_BIT;
+	unsigned long flags;
+
+	flags = arch_local_save_flags();
+
+	/*
+	 * There are too many states with IRQs disabled, just keep the current
+	 * state if interrupts are already disabled/masked.
+	 */
+	if (!arch_irqs_disabled_flags(flags))
+		arch_local_irq_disable();
+
+	return flags;
 }
 
 /*
- * save and restore debug state
+ * restore saved IRQ state
  */
-#define local_dbg_save(flags)						\
-	do {								\
-		typecheck(unsigned long, flags);			\
-		asm volatile(						\
-		"mrs    %0, daif		// local_dbg_save\n"	\
-		"msr    daifset, #8"					\
-		: "=r" (flags) : : "memory");				\
-	} while (0)
-
-#define local_dbg_restore(flags)					\
-	do {								\
-		typecheck(unsigned long, flags);			\
-		asm volatile(						\
-		"msr    daif, %0		// local_dbg_restore\n"	\
-		: : "r" (flags) : "memory");				\
-	} while (0)
-
-#endif
-#endif
+static inline void arch_local_irq_restore(unsigned long flags)
+{
+	asm volatile(ALTERNATIVE(
+		"msr	daif, %0",
+		__msr_s(SYS_ICC_PMR_EL1, "%0"),
+		ARM64_HAS_IRQ_PRIO_MASKING)
+		:
+		: "r" (flags)
+		: "memory");
+
+	pmr_sync();
+}
+
+#endif /* __ASM_IRQFLAGS_H */