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authorFabio Estevam <festevam@gmail.com>2013-07-23 15:13:06 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-07-26 12:02:09 +0100
commit1f49856bb029779d8f1b63517a3a3b34ffe672c7 (patch)
tree2fa00a1dc1f50c04c7c3fd339f534275e213590b /arch
parent8fbac214e5c594a0c2fe78c14adf2cdbb1febc92 (diff)
downloadlinux-1f49856bb029779d8f1b63517a3a3b34ffe672c7.tar.bz2
ARM: 7789/1: Do not run dummy_flush_tlb_a15_erratum() on non-Cortex-A15
Commit 93dc688 (ARM: 7684/1: errata: Workaround for Cortex-A15 erratum 798181 (TLBI/DSB operations)) causes the following undefined instruction error on a mx53 (Cortex-A8): Internal error: Oops - undefined instruction: 0 [#1] SMP ARM CPU: 0 PID: 275 Comm: modprobe Not tainted 3.11.0-rc2-next-20130722-00009-g9b0f371 #881 task: df46cc00 ti: df48e000 task.ti: df48e000 PC is at check_and_switch_context+0x17c/0x4d0 LR is at check_and_switch_context+0xdc/0x4d0 This problem happens because check_and_switch_context() calls dummy_flush_tlb_a15_erratum() without checking if we are really running on a Cortex-A15 or not. To avoid this issue, only call dummy_flush_tlb_a15_erratum() inside check_and_switch_context() if erratum_a15_798181() returns true, which means that we are really running on a Cortex-A15. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Roger Quadros <rogerq@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/include/asm/tlbflush.h16
-rw-r--r--arch/arm/kernel/smp_tlb.c17
-rw-r--r--arch/arm/mm/context.c3
3 files changed, 18 insertions, 18 deletions
diff --git a/arch/arm/include/asm/tlbflush.h b/arch/arm/include/asm/tlbflush.h
index fdbb9e369745..f467e9b3f8d5 100644
--- a/arch/arm/include/asm/tlbflush.h
+++ b/arch/arm/include/asm/tlbflush.h
@@ -443,7 +443,18 @@ static inline void local_flush_bp_all(void)
isb();
}
+#include <asm/cputype.h>
#ifdef CONFIG_ARM_ERRATA_798181
+static inline int erratum_a15_798181(void)
+{
+ unsigned int midr = read_cpuid_id();
+
+ /* Cortex-A15 r0p0..r3p2 affected */
+ if ((midr & 0xff0ffff0) != 0x410fc0f0 || midr > 0x413fc0f2)
+ return 0;
+ return 1;
+}
+
static inline void dummy_flush_tlb_a15_erratum(void)
{
/*
@@ -453,6 +464,11 @@ static inline void dummy_flush_tlb_a15_erratum(void)
dsb();
}
#else
+static inline int erratum_a15_798181(void)
+{
+ return 0;
+}
+
static inline void dummy_flush_tlb_a15_erratum(void)
{
}
diff --git a/arch/arm/kernel/smp_tlb.c b/arch/arm/kernel/smp_tlb.c
index a98b62dca2fa..c2edfff573c2 100644
--- a/arch/arm/kernel/smp_tlb.c
+++ b/arch/arm/kernel/smp_tlb.c
@@ -70,23 +70,6 @@ static inline void ipi_flush_bp_all(void *ignored)
local_flush_bp_all();
}
-#ifdef CONFIG_ARM_ERRATA_798181
-static int erratum_a15_798181(void)
-{
- unsigned int midr = read_cpuid_id();
-
- /* Cortex-A15 r0p0..r3p2 affected */
- if ((midr & 0xff0ffff0) != 0x410fc0f0 || midr > 0x413fc0f2)
- return 0;
- return 1;
-}
-#else
-static int erratum_a15_798181(void)
-{
- return 0;
-}
-#endif
-
static void ipi_flush_tlb_a15_erratum(void *arg)
{
dmb();
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index b55b1015724b..4a0544492f10 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -245,7 +245,8 @@ void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk)
if (cpumask_test_and_clear_cpu(cpu, &tlb_flush_pending)) {
local_flush_bp_all();
local_flush_tlb_all();
- dummy_flush_tlb_a15_erratum();
+ if (erratum_a15_798181())
+ dummy_flush_tlb_a15_erratum();
}
atomic64_set(&per_cpu(active_asids, cpu), asid);