Re: [PATCH] x86: Quark: Add if/else to setup_arch for Quark TLB bug

Dave Jones
2014-09-26T17:36:10Z

On Fri, Sep 26, 2014 at 06:19:45PM +0100, Bryan O'Donoghue wrote:
> Quark X1000 incorrectly advertises PGE. In later the stages of boot
> specifically in early_init_intel we setup_clear_cpu_cap for PGE.
> At this point in time cpu_has_pge() will still be true.
>
> Use the boot_cpu_data to decide if __flush_tlb_all() or __flush_tlb()
> should be called subsequent to loading CR3

> + * Flush the TLB after loading CR3
> + *
> + * Quark X1000 wrongly advertises PGE. Use boot_cpu_data to
> + * to make sure the TLB is flushed correctly in the early
> + * stage of setup_arch() for Quark X1000.
> + * X86_FEATURE_PGE flag is only setup later stage at
> + * early_cpu_init();
> + */
> + if (boot_cpu_data.x86 == 5 && boot_cpu_data.x86_model == 9)
> + __flush_tlb();

This also needs a check for the cpu vendor, or this will apply
the workaround on for eg, AMD K6-III's.

Dave