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authorNishanth Menon <nm@ti.com>2015-03-09 17:12:02 -0500
committerTom Rini <trini@konsulko.com>2015-03-13 09:28:53 -0400
commit9b4d65f918dd84a479552b86ef2cde389926738f (patch)
treed39cc80675c8a98f672ceeec21fcd1183371dabc /arch
parent5902f4ce0f2bd1411e40dc0ece3598a0fc19b2ae (diff)
ARM: Introduce erratum workaround for 621766
621766: Under a specific set of conditions, executing a sequence of NEON or vfp load instructions can cause processor deadlock Impacts: Every Cortex-A8 processors with revision lower than r2p1 Work around: Set L1NEON to 1 Based on ARM errata Document revision 20.0 (13 Nov 2010) Signed-off-by: Nishanth Menon <nm@ti.com> Tested-by: Matt Porter <mporter@konsulko.com> Reviewed-by: Tom Rini <trini@konsulko.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/cpu/armv7/start.S13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
index 41fb24cf32..5050021e02 100644
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -215,6 +215,19 @@ skip_errata_454179:
skip_errata_430973:
#endif
+#ifdef CONFIG_ARM_ERRATA_621766
+ cmp r2, #0x21 @ Only on < r2p1
+ bge skip_errata_621766
+
+ mrc p15, 0, r0, c1, c0, 1 @ Read ACR
+ orr r0, r0, #(0x1 << 5) @ Set L1NEON bit
+ push {r1-r5} @ Save the cpu info registers
+ bl v7_arch_cp15_set_acr
+ pop {r1-r5} @ Restore the cpu info - fall through
+
+skip_errata_621766:
+#endif
+
mov pc, r5 @ back to my caller
ENDPROC(cpu_init_cp15)