ARM: V7M: Support caches

Quoted 25 lines · Vladimir Murzin

Quoted 23 lines · Russell King - ARM Linux

Quoted 13 lines · Vladimir Murzin

This patch set allows M-class cpus benefit of optional cache support. It originally was written by Jonny, I've been keeping it locally mainly rebasing over Linux versions.

The original idea behind patches was to reuse existing cache handling code from v7A/R with help of extra macros to factor out cache handling logic (v7M cache operations are provided via memory mapped interface rather than co-processor instructions).
However, that idea was rejected and starting form this (v2) version V7M cache logic lives into file and macros to indirect memory-mapped operations stay there locally since they make it easier to follow the code.

Quoted 7 lines

Along with the v7M cache support the first user (Cortex-M7) is introduced.

Patches were tested on MPS2 platform with Cortex-M3/M4/M7. The later one showed significant boot speed-up.

From a quick read through, the approach looks sane, and I think I'm

now happy with these.

Quoted 4 lines

Thanks!

Is it acceptable if patches hang on a list for awhile, so people (I'm looking at Alex and Szemz?) can test them?

Of course.