From: Roland McGrath <roland@redhat.com>
To: linuxppc-dev@ozlabs.org
Subject: how to check for "optional" ppc chip features (MSR_BE)
Date: Thu, 1 May 2008 18:21:18 -0700 (PDT) [thread overview]
Message-ID: <20080502012118.96ED926FA07@magilla.localdomain> (raw)
I've been looking at PowerISA_Public.pdf that I downloaded from some ppc
site. It describes various things as "need not be supported on all
implementations", for example the MSR_BE bit. Is there a generic way to
detect if such a feature is supported, or a known table of models that
support features, or what?
Right now I'm considering MSR_BE (branch tracing). I have a patch to use
this (arch_has_block_step, enabling a PTRACE_SINGLEBLOCK). The only
machine handy to test is a Mac G5 (PPC970FX, 3.0 (pvr 003c 0300)). I know
this chip supports MSR_BE. But that's only because I wrote an affirmative
test case and tried it and saw it work right.
Before submitting the kernel changes, I want to get the CPU model
conditionalization correct (a runtime check on some feature bit mask is
fine here, if CONFIG_* alone does not indicate for sure).
Thanks,
Roland
next reply other threads:[~2008-05-02 1:21 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-02 1:21 Roland McGrath [this message]
2008-05-02 3:48 ` how to check for "optional" ppc chip features (MSR_BE) Kumar Gala
2008-05-04 21:45 ` Benjamin Herrenschmidt
2008-05-04 23:12 ` Roland McGrath
2008-05-05 0:49 ` Benjamin Herrenschmidt
2008-05-13 11:55 ` Paul Mackerras
2008-05-13 13:47 ` Kumar Gala
2008-05-13 19:33 ` Roland McGrath
2008-06-11 16:05 ` Kumar Gala
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