[PATCH v2] tracing: Add register read and write tracing support

[Will Deacon]

On Fri, Nov 06, 2020 at 07:49:29AM +0100, Greg KH wrote:
> On Thu, Nov 05, 2020 at 06:56:26PM -0800, Prasad Sodagudi wrote:
> > Add register read/write operations tracing support.
> > ftrace events helps to trace register read and write
> > location details of memory mapped IO registers.
> 
> This sentance does not parse for me, can you please rework it?
> 
> > These trace logs helps to debug un clocked access
> > of peripherals.
> 
> "un clocked"?  What does that mean?
> 
> And you do have 72 columns to fill, please use it :)
> 
> > 
> > Signed-off-by: Prasad Sodagudi <psodagud at codeaurora.org>
> > ---
> >  arch/arm64/include/asm/io.h    |  9 ++++++++
> >  arch/arm64/kernel/image-vars.h |  8 +++++++
> 
> You are only adding it for arm64, why not add the generic support first,
> and then add it for all "major" arches afterwards?

Yeah, or just hook the higher-level accessors rather than the arch-specific
bowels. Less work for more coverage that way!

Will