[U-Boot] [PATCH] armv8: fsl-layerscape: Add support of disabling core prefetch

[York Sun]

On 11/08/2017 06:48 PM, Prabhakar Kushwaha wrote:
> Instruction prefetch feature is by default enabled during core
> release.
> 
> This patch add support of disabling instruction prefetch by setting
> core mask in PPA. Here each core mask bit represents a core and
> prefetch is disabled at the time of core release.
> 
> Signed-off-by: Prabhakar Kushwaha <prabhakar.kushwaha at nxp.com>
> ---
>  arch/arm/cpu/armv8/fsl-layerscape/cpu.c            | 38 ++++++++++++++++++++++
>  .../armv8/fsl-layerscape/doc/README.core_prefetch  | 18 ++++++++++
>  2 files changed, 56 insertions(+)
>  create mode 100644 arch/arm/cpu/armv8/fsl-layerscape/doc/README.core_prefetch

<snip>

> diff --git a/arch/arm/cpu/armv8/fsl-layerscape/doc/README.core_prefetch b/arch/arm/cpu/armv8/fsl-layerscape/doc/README.core_prefetch
> new file mode 100644
> index 0000000..f605a4c
> --- /dev/null
> +++ b/arch/arm/cpu/armv8/fsl-layerscape/doc/README.core_prefetch
> @@ -0,0 +1,18 @@
> +Core instruction prefetch disable
> +---------------------------------
> +To disable instruction prefetch of core; hwconfig needs to be updated.
> +for e.g.
> +setenv hwconfig 'fsl_ddr:bank_intlv=auto;core_prefetch:disable=0x02'
> +

Why would one want to disable prefetch? And environmental variables are
not available for some SPL boot (eg. SD) last time I check.

York