ARM: implement some Cortex-A9 errata workarounds
Various errata exist in the Cortex-A9 CPU, and may be worked around by
setting some bits in a CP15 diagnostic register. Add code to implement
the workarounds, enabled by new CONFIG_ options.
This code was taken from the Linux kernel, v3.8, arch/arm/mm/proc-v7.S,
and modified to remove the logic to conditionally apply the WAR (since we
know exactly which CPU we're running on given the U-Boot configuration),
and use r0 instead of r10 for consistency with the rest of U-Boot's
cpu_init_cp15().
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
index 6b59529d..30f02d3 100644
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -309,6 +309,25 @@
orr r0, r0, #0x00001000 @ set bit 12 (I) I-cache
#endif
mcr p15, 0, r0, c1, c0, 0
+
+#ifdef CONFIG_ARM_ERRATA_742230
+ mrc p15, 0, r0, c15, c0, 1 @ read diagnostic register
+ orr r0, r0, #1 << 4 @ set bit #4
+ mcr p15, 0, r0, c15, c0, 1 @ write diagnostic register
+#endif
+
+#ifdef CONFIG_ARM_ERRATA_743622
+ mrc p15, 0, r0, c15, c0, 1 @ read diagnostic register
+ orr r0, r0, #1 << 6 @ set bit #6
+ mcr p15, 0, r0, c15, c0, 1 @ write diagnostic register
+#endif
+
+#ifdef CONFIG_ARM_ERRATA_751472
+ mrc p15, 0, r0, c15, c0, 1 @ read diagnostic register
+ orr r0, r0, #1 << 11 @ set bit #11
+ mcr p15, 0, r0, c15, c0, 1 @ write diagnostic register
+#endif
+
mov pc, lr @ back to my caller
ENDPROC(cpu_init_cp15)