[PATCH v2] ARM: Add imprecise abort enable/disable macro

From: Fabrice GASNIER
Date: Mon Feb 10 2014 - 11:46:49 EST


This patch adds imprecise abort enable/disable macros.
It also enables imprecise aborts when starting kernel.

Changes in v2:
Only ARMv6 and later have CPSR.A bit. On earlier CPUs,
and ARMv7M this should be a no-op.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
---
arch/arm/include/asm/irqflags.h | 10 ++++++++++
arch/arm/kernel/smp.c | 1 +
arch/arm/kernel/traps.c | 4 ++++
3 files changed, 15 insertions(+)

diff --git a/arch/arm/include/asm/irqflags.h b/arch/arm/include/asm/irqflags.h
index 3b763d6..8301f87 100644
--- a/arch/arm/include/asm/irqflags.h
+++ b/arch/arm/include/asm/irqflags.h
@@ -51,6 +51,14 @@ static inline void arch_local_irq_disable(void)

#define local_fiq_enable() __asm__("cpsie f @ __stf" : : : "memory", "cc")
#define local_fiq_disable() __asm__("cpsid f @ __clf" : : : "memory", "cc")
+
+#ifndef CONFIG_CPU_V7M
+#define local_abt_enable() __asm__("cpsie a @ __sta" : : : "memory", "cc")
+#define local_abt_disable() __asm__("cpsid a @ __cla" : : : "memory", "cc")
+#else
+#define local_abt_enable() do { } while (0)
+#define local_abt_disable() do { } while (0)
+#endif
#else

/*
@@ -130,6 +138,8 @@ static inline void arch_local_irq_disable(void)
: "memory", "cc"); \
})

+#define local_abt_enable() do { } while (0)
+#define local_abt_disable() do { } while (0)
#endif

/*
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index dc894ab..c2093cb 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -377,6 +377,7 @@ asmlinkage void secondary_start_kernel(void)

local_irq_enable();
local_fiq_enable();
+ local_abt_enable();

/*
* OK, it's off to the idle thread for us
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 4636d56..ef15709 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -900,6 +900,10 @@ void __init early_trap_init(void *vectors_base)

flush_icache_range(vectors, vectors + PAGE_SIZE * 2);
modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
+
+ /* Enable imprecise aborts */
+ local_abt_enable();
+
#else /* ifndef CONFIG_CPU_V7M */
/*
* on V7-M there is no need to copy the vector table to a dedicated
--
1.7.9.5

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