[PATCH v2 1/6] arm: Add BTB invalidation on switch_mm for Cortex-A9, A12 and A17

[Fabio Estevam]

Hi Marc,

On Mon, Jan 29, 2018 at 4:41 PM, Fabio Estevam <festevam at gmail.com> wrote:
> Hi Marc,
>
> On Thu, Jan 11, 2018 at 7:03 AM, Marc Zyngier <marc.zyngier at arm.com> wrote:
>
>>> OK. in u-boot, I had helped on the following:
>>> http://git.denx.de/?p=u-boot.git;a=commitdiff;h=5902f4ce0f2bd1411e40dc0ece3598a0fc19b2ae
>>>
>>> maybe be build off that?
>>
>> Turn that into something unconditional, and you'll be good.

Maybe by 'unconditional' you mean the revision check like this?

--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -249,16 +249,13 @@ skip_errata_801819:
        pop     {r1-r5}                 @ Restore the cpu info - fall through
 #endif

-#ifdef CONFIG_ARM_ERRATA_430973
        mrc     p15, 0, r0, c1, c0, 1   @ Read ACR

-       cmp     r2, #0x21               @ Only on < r2p1
-       orrlt   r0, r0, #(0x1 << 6)     @ Set IBE bit
+       orr     r0, r0, #(0x1 << 6)     @ Set IBE bit

        push    {r1-r5}                 @ Save the cpu info registers
        bl      v7_arch_cp15_set_acr
        pop     {r1-r5}                 @ Restore the cpu info - fall through
-#endif

 #ifdef CONFIG_ARM_ERRATA_621766