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authorLucas Stach <l.stach@pengutronix.de>2015-10-19 13:38:09 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2015-10-19 17:08:33 +0100
commit9254970cbbf542a0085e491810f0144a27885702 (patch)
treef46c0c1ce8575aecc8133703117a1be5ab181ad1 /arch/arm/mm
parentc8d46ece44458a2088896d6fcae123a72bdfd429 (diff)
downloadlinux-linaro-stable-9254970cbbf542a0085e491810f0144a27885702.tar.gz
ARM: 8447/1: catch pending imprecise abort on unmask
Install a non-faulting handler just before unmasking imprecise aborts and switch back to the regular one after unmasking is done. This catches any pending imprecise abort that the firmware/bootloader may have left behind that would normally crash the kernel at that point. As there are apparently a lot of bootlaoders out there that do such a thing it makes sense to handle it in the common startup code. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Tested-by: Tyler Baker <tyler.baker@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm')
-rw-r--r--arch/arm/mm/fault.c22
-rw-r--r--arch/arm/mm/fault.h1
-rw-r--r--arch/arm/mm/mmu.c3
3 files changed, 25 insertions, 1 deletions
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 0d629b8f973f..daafcf121ce0 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -593,6 +593,28 @@ do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs)
arm_notify_die("", regs, &info, ifsr, 0);
}
+/*
+ * Abort handler to be used only during first unmasking of asynchronous aborts
+ * on the boot CPU. This makes sure that the machine will not die if the
+ * firmware/bootloader left an imprecise abort pending for us to trip over.
+ */
+static int __init early_abort_handler(unsigned long addr, unsigned int fsr,
+ struct pt_regs *regs)
+{
+ pr_warn("Hit pending asynchronous external abort (FSR=0x%08x) during "
+ "first unmask, this is most likely caused by a "
+ "firmware/bootloader bug.\n", fsr);
+
+ return 0;
+}
+
+void __init early_abt_enable(void)
+{
+ fsr_info[22].fn = early_abort_handler;
+ local_abt_enable();
+ fsr_info[22].fn = do_bad;
+}
+
#ifndef CONFIG_ARM_LPAE
static int __init exceptions_init(void)
{
diff --git a/arch/arm/mm/fault.h b/arch/arm/mm/fault.h
index cf08bdfbe0d6..05ec5e0df32d 100644
--- a/arch/arm/mm/fault.h
+++ b/arch/arm/mm/fault.h
@@ -24,5 +24,6 @@ static inline int fsr_fs(unsigned int fsr)
void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs);
unsigned long search_exception_table(unsigned long addr);
+void early_abt_enable(void);
#endif /* __ARCH_ARM_FAULT_H */
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index f65a6f344b6d..4867f5daf82c 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -38,6 +38,7 @@
#include <asm/mach/pci.h>
#include <asm/fixmap.h>
+#include "fault.h"
#include "mm.h"
#include "tcm.h"
@@ -1365,7 +1366,7 @@ static void __init devicemaps_init(const struct machine_desc *mdesc)
flush_cache_all();
/* Enable asynchronous aborts */
- local_abt_enable();
+ early_abt_enable();
}
static void __init kmap_init(void)