On Thu, 2008-05-22 at 13:51 +1000, Paul Mackerras wrote:

Luis Machado writes:

quoted

This is a patch that has been sitting idle for quite some time. I
decided to move it further because it is something useful. It was
originally written by Michel Darneille, based off of 2.6.16.

The original patch, though, was not compatible with the current DABR
logic. DABR's are used to implement hardware watchpoint support for
ppc64 processors (i.e. 970, Power5 etc). 4xx's have a different
debugging register layout and needs to be handled differently (they two
registers: DAC and DBCR0).

Yes, they are different, but they do essentially the same thing, so I
think we should try and unify the handling of the two.  Maybe you
could rename set_dabr() to set_hw_watchpoint() or something and make
it set DABR on 64-bit and "classic" 32-bit processors, and DAC on
4xx/Book E processors.

Likewise, I don't think we need both a "dabr" field and a "dac" field
in the thread_struct - one should do.  Rename "dabr" to something else
if you feel that the "dabr" name is too ppc64-specific.  And I don't
think we need both __debugger_dabr_match and __debugger_dac_match.

Thanks for the feedback Paul. I'll try consolidating those mechanisms
into a single, more general scheme. 

Best regards,
Luis