430973: Stale prediction on replaced inter working branch causes
        Cortex-A8 to execute in the wrong ARM/Thumb state
Impacts: Every Cortex-A8 processors with revision lower than r2p1
Work around: Set IBE to 1

Based on ARM errata Document revision 20.0 (13 Nov 2010)

Signed-off-by: Nishanth Menon <n...@ti.com>
---
 README                     |    1 +
 arch/arm/cpu/armv7/start.S |   13 +++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/README b/README
index e538cf061286..484ae9ee39a8 100644
--- a/README
+++ b/README
@@ -624,6 +624,7 @@ The following options need to be configured:
                NOTE: The following can be machine specific errata. These
                do have ability to provide rudimentary version and machine
                specific checks, but expect no product checks.
+               CONFIG_ARM_ERRATA_430973
                CONFIG_ARM_ERRATA_454179
                CONFIG_ARM_ERRATA_798870
 
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
index 1516ed675dac..99220ce76a25 100644
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -198,6 +198,19 @@ skip_errata_798870:
 skip_errata_454179:
 #endif
 
+#ifdef CONFIG_ARM_ERRATA_430973
+       cmp     r2, #0x21               @ Only on < r2p1
+       bge     skip_errata_430973
+
+       mrc     p15, 0, r0, c1, c0, 1   @ Read ACR
+       orr     r0, r0, #(0x1 << 6)     @ Set IBE bit
+       push    {r1-r4}                 @ Save the cpu info registers
+       b       v7_arch_cp15_set_acr
+       pop     {r1-r4}                 @ Restore the cpu info - fall through
+
+skip_errata_430973:
+#endif
+
        mov     pc, lr                  @ back to my caller
 ENDPROC(cpu_init_cp15)
 
-- 
1.7.9.5

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