[SRU][Zesty][PATCH 2/4] [PATCH 2/4] powerpc/mm/radix: Improve _tlbiel_pid to be usable for PWC flushes

[Joseph Salisbury]

From: Benjamin Herrenschmidt <benh at kernel.crashing.org>

BugLink: http://bugs.launchpad.net/bugs/1709220

The PWC flush only needs a single set call, just like the
full (RIC=2) flush.

This will allow us to get rid of the dedicated _tlbiel_pwc()

Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
(cherry picked from linux-next commit 5ce5fe14ed0302315061cf97ce67accd1b25b938)
Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>
---
 arch/powerpc/mm/tlb-radix.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c
index 5e531e4..f1af3ab 100644
--- a/arch/powerpc/mm/tlb-radix.c
+++ b/arch/powerpc/mm/tlb-radix.c
@@ -53,12 +53,15 @@ static inline void _tlbiel_pid(unsigned long pid, unsigned long ric)
 	 */
 	__tlbiel_pid(pid, 0, ric);
 
-	if (ric == RIC_FLUSH_ALL)
-		/* For the remaining sets, just flush the TLB */
-		ric = RIC_FLUSH_TLB;
+	/* For PWC, only one flush is needed */
+	if (ric == RIC_FLUSH_PWC) {
+		asm volatile("ptesync": : :"memory");
+		return;
+	}
 
+	/* For the remaining sets, just flush the TLB */
 	for (set = 1; set < POWER9_TLB_SETS_RADIX ; set++)
-		__tlbiel_pid(pid, set, ric);
+		__tlbiel_pid(pid, set, RIC_FLUSH_TLB);
 
 	asm volatile("ptesync": : :"memory");
 	asm volatile(PPC_INVALIDATE_ERAT "; isync" : : :"memory");
-- 
2.7.4