[PATCH] PPC: fix LOGMPP instruction opcode and inline asm

Stewart Smith stewart at linux.vnet.ibm.com
Fri Oct 16 14:53:35 AEDT 2015


Michael Ellerman <mpe at ellerman.id.au> writes:
> On Fri, 2015-10-16 at 12:20 +1100, Stewart Smith wrote:
>> Back in 9678cda when we started using the Micro Partition Prefetch Engine
>> in POWER8 for KVM, there were two mistakes introduced from the original
>> patch used for investigation and microbenchmarks.
>> 
>> One mistake was that the opcode was constructed incorrectly, putting
>> the register in the wrong field in the opcode, meaning that we were
>> asking the chip to read the memory address from some other register than
>> what we intended - probably r0.
>
> Where is the logmpp instruction documented?

BookIV Section 5.1 - although I think this is now meant to all be in the
"P8 User Manual".



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