[PATCH 4.9 45/60] powerpc/mm/radix: Update ERAT flushes when invalidating TLB

From: Greg Kroah-Hartman
Date: Mon Feb 13 2017 - 08:15:57 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>

commit 90c1e3c2fafec57fcb55b5d69bcf293b1a5fc8b3 upstream.

Three tiny changes to the ERAT flushing logic: First don't make
it depend on DD1. It hasn't been decided yet but we might run
DD2 in a mode that also requires explicit flushes for performance
reasons so make it unconditional. We also add a missing isync, and
finally remove the flush from _tlbiel_va as it is only necessary
for congruence-class invalidations (PID, LPID and full TLB), not
targetted invalidations.

Fixes: 96ed1fe511a8 ("powerpc/mm/radix: Invalidate ERAT on tlbiel for POWER9 DD1")
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/powerpc/mm/tlb-radix.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

--- a/arch/powerpc/mm/tlb-radix.c
+++ b/arch/powerpc/mm/tlb-radix.c
@@ -50,9 +50,7 @@ static inline void _tlbiel_pid(unsigned
for (set = 0; set < POWER9_TLB_SETS_RADIX ; set++) {
__tlbiel_pid(pid, set, ric);
}
- if (cpu_has_feature(CPU_FTR_POWER9_DD1))
- asm volatile(PPC_INVALIDATE_ERAT : : :"memory");
- return;
+ asm volatile(PPC_INVALIDATE_ERAT "; isync" : : :"memory");
}

static inline void _tlbie_pid(unsigned long pid, unsigned long ric)
@@ -85,8 +83,6 @@ static inline void _tlbiel_va(unsigned l
asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
: : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory");
asm volatile("ptesync": : :"memory");
- if (cpu_has_feature(CPU_FTR_POWER9_DD1))
- asm volatile(PPC_INVALIDATE_ERAT : : :"memory");
}

static inline void _tlbie_va(unsigned long va, unsigned long pid,