Re: [PATCH] MIPS: Add option to work around CN68XXP1 PREF errata.

[David Daney <ddaney at caviumnetworks dot com>]

On 09/27/2010 05:48 PM, David Daney wrote:
> The CN68XXP1 is a member of the OCTEON family of MIPS64 based SOCs.  The

Just for clarification, both in the subject line and right here I have a 
typo.  The part in question is CN63XXP1.  The changelog and patch have 
the correct name.

Sorry for any confusion this may have caused.
David Daney


> CPUs on this device have an erratum where execution of PREF instructions
> with hints in the range 0-4 and 6-24 occasionally lead to undefined
> behavior.
>
> We have implemented a work around in the assembler where we replace PREF
> instructions that might fail with PREF 28. This work around is
> enabled/disabled with the new command line options '-mfix-cn63xxp1' /
> '-mno-fix-cn63xxp1'.
>
> Tested with --target=mips64-octeon-linux-gnu, no regressions.
>
> OK to commit?
>
> src/gas:
> 2010-09-27 David Daney <ddaney@caviumnetworks.com>
>
> * config/tc-mips.c (mips_fix_cn63xxp1): New variable.
> (mips_ip): Add errata work around when mips_fix_cn63xxp1 set.
> (OPTION_FIX_CN63XXP1, OPTION_NO_FIX_CN63XXP1): New enum options
> enumerations.
> (md_longopts): Add options for -mfix-cn63xxp1 and -mno-fix-cn63xxp1.
> (md_parse_option): Handle OPTION_FIX_CN63XXP1 and
> OPTION_NO_FIX_CN63XXP1.
> (md_show_usage): Add documentation for -mfix-cn63xxp1.
> * doc/c-mips.texi (-mfix-cn63xxp1, -mno-fix-cn63xxp1): Document
> the new options.
>
> src/gas/testsuite:
> 2010-09-27 David Daney <ddaney@caviumnetworks.com>
>
> * gas/mips/mips.exp (octeon-pref): Run the new test.
> * gas/mips/octeon-pref.s: New test.
> * gas/mips/octeon-pref.d: New expected results for the new test.