On Mon, 7 May 2018 15:15:26 +1000
Paul Mackerras <paulus@xxxxxxxxxx> wrote:
> On Sun, May 06, 2018 at 05:37:27PM +1000, Nicholas Piggin wrote:
> > Implement a local TLB flush for invalidating an LPID with variants for
> > process or partition scope. And a global TLB flush for invalidating
> > a partition scoped page of an LPID.
> >
> > These will be used by KVM in subsequent patches.
> >
> > Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
> > ---
> > .../include/asm/book3s/64/tlbflush-radix.h | 7 +
> > arch/powerpc/mm/tlb-radix.c | 207 ++++++++++++++++++
> > 2 files changed, 214 insertions(+)
> >
> > diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
> > index 19b45ba6caf9..ef5c3f2994c9 100644
> > --- a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
> > +++ b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
> > @@ -51,4 +51,11 @@ extern void radix__flush_tlb_all(void);
> > extern void radix__flush_tlb_pte_p9_dd1(unsigned long old_pte, struct mm_struct *mm,
> > unsigned long address);
> >
> > +extern void radix__flush_tlb_lpid_page(unsigned int lpid,
> > + unsigned long addr,
> > + unsigned long page_size);
> > +extern void radix__flush_pwc_lpid(unsigned int lpid);
> > +extern void radix__local_flush_tlb_lpid(unsigned int lpid);
> > +extern void radix__local_flush_tlb_lpid_guest(unsigned int lpid);
> > +
> > #endif
> > diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c
> > index a5d7309c2d05..5ac3206c51cc 100644
> > --- a/arch/powerpc/mm/tlb-radix.c
> > +++ b/arch/powerpc/mm/tlb-radix.c
> > @@ -118,6 +118,53 @@ static inline void __tlbie_pid(unsigned long pid, unsigned long ric)
> > trace_tlbie(0, 0, rb, rs, ric, prs, r);
> > }
> >
> > +static inline void __tlbiel_lpid(unsigned long lpid, int set,
> > + unsigned long ric)
> > +{
> > + unsigned long rb,rs,prs,r;
> > +
> > + rb = PPC_BIT(52); /* IS = 2 */
> > + rb |= set << PPC_BITLSHIFT(51);
> > + rs = 0; /* LPID comes from LPIDR */
> > + prs = 0; /* partition scoped */
> > + r = 1; /* radix format */
> > +
> > + asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
> > + : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory");
> > + trace_tlbie(lpid, 1, rb, rs, ric, prs, r);
>
> Do we really want 128 trace entries every time
> radix__local_flush_tlb_lpid() or radix__local_flush_tlb_lpid_guest()
> is called? That seems like overkill to me. Could we move the
> trace_tlbie calls here and in __tlbiel_lpid_guest() into the callers
> instead?
Yeah well that's how the powerpc:tlbie tracepoints are defined. I can
see possible benefit to feeding the trace directly to a model or
simulator, but it does make other things harder.
I have a patch around that changes all those tracepoints around to
match the Linux semantics rather than the instructions... If people
would prefer that I can send it (cc'ed Balbir).
But for this patch we should just match the existing tracepoints.
Thanks,
Nick
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