diff options
| author | Stephen Warren <swarren@nvidia.com> | 2013-02-26 12:28:27 +0000 |
|---|---|---|
| committer | Albert ARIBAUD <albert.u.boot@aribaud.net> | 2013-03-13 22:24:11 +0100 |
| commit | 0678587fb6f517d40c461f1d43fe7a6ff430f168 (patch) | |
| tree | f740ba06aaa5333ba187b291e687a03054bd936f | |
| parent | ef123c525370463254a6f8e67563fdb0b0b46412 (diff) | |
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>
| -rw-r--r-- | README | 10 | ||||
| -rw-r--r-- | arch/arm/cpu/armv7/start.S | 19 |
2 files changed, 29 insertions, 0 deletions
@@ -485,6 +485,16 @@ The following options need to be configured: Thumb2 this flag will result in Thumb2 code generated by GCC. + CONFIG_ARM_ERRATA_742230 + CONFIG_ARM_ERRATA_743622 + CONFIG_ARM_ERRATA_751472 + + If set, the workarounds for these ARM errata are applied early + during U-Boot startup. Note that these options force the + workarounds to be applied; no CPU-type/version detection + exists, unlike the similar options in the Linux kernel. Do not + set these options unless they apply! + - Linux Kernel Interface: CONFIG_CLOCKS_IN_MHZ diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S index 6b59529d5dd..30f02d39435 100644 --- a/arch/arm/cpu/armv7/start.S +++ b/arch/arm/cpu/armv7/start.S @@ -309,6 +309,25 @@ ENTRY(cpu_init_cp15) 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) |