powerpc/xmon: Add 'dt' command to dump trace buffers

[Michael Ellerman]

On Fri, 2015-11-06 at 02:21:17 UTC, Michael Ellerman wrote:
> There is a nice interface for asking ftrace to dump all its tracing
> buffers. The only down side for use in xmon is that it uses printk.
> Depending on circumstances printk may not work when in xmon, but it also
> may, so add a 'dt' command which dumps the ftrace buffers, and add a
> note to the help to mentiont that it uses printk.
> 
> Calling this routine also disables tracing, which is problematic if you
> return from xmon and expect the system to keep operating normally. So
> after we do the dump turn tracing back on.
> 
> Both functions already have nop versions defined for when ftrace is not
> enabled, so we don't need any extra #ifdefs.
> 
> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>

Applied to powerpc next.

https://git.kernel.org/powerpc/c/56144ec7c93f6f18aa878560074633

cheers