[RFC PATCH v2 06/10] KVM: PPC: Ultravisor: Restrict flush of the partition tlb cache

[Claudio Carvalho]

From: Ram Pai <linuxram at us.ibm.com>

Ultravisor is responsible for flushing the tlb cache, since it manages
the PATE entries. Hence skip tlb flush, if the ultravisor firmware is
available.

Signed-off-by: Ram Pai <linuxram at us.ibm.com>
Signed-off-by: Claudio Carvalho <cclaudio at linux.ibm.com>
---
 arch/powerpc/mm/book3s64/pgtable.c | 33 +++++++++++++++++-------------
 1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index 40a9fc8b139f..1eeb5fe87023 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -224,6 +224,23 @@ void __init mmu_partition_table_init(void)
 	powernv_set_nmmu_ptcr(ptcr);
 }
 
+static void flush_partition(unsigned int lpid, unsigned long dw0)
+{
+	if (dw0 & PATB_HR) {
+		asm volatile(PPC_TLBIE_5(%0, %1, 2, 0, 1) : :
+			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
+		asm volatile(PPC_TLBIE_5(%0, %1, 2, 1, 1) : :
+			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
+		trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 1);
+	} else {
+		asm volatile(PPC_TLBIE_5(%0, %1, 2, 0, 0) : :
+			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
+		trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 0);
+	}
+	/* do we need fixup here ?*/
+	asm volatile("eieio; tlbsync; ptesync" : : : "memory");
+}
+
 static void __mmu_partition_table_set_entry(unsigned int lpid,
 					    unsigned long dw0,
 					    unsigned long dw1)
@@ -238,20 +255,8 @@ static void __mmu_partition_table_set_entry(unsigned int lpid,
 	 * The type of flush (hash or radix) depends on what the previous
 	 * use of this partition ID was, not the new use.
 	 */
-	asm volatile("ptesync" : : : "memory");
-	if (old & PATB_HR) {
-		asm volatile(PPC_TLBIE_5(%0,%1,2,0,1) : :
-			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
-		asm volatile(PPC_TLBIE_5(%0,%1,2,1,1) : :
-			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
-		trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 1);
-	} else {
-		asm volatile(PPC_TLBIE_5(%0,%1,2,0,0) : :
-			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
-		trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 0);
-	}
-	/* do we need fixup here ?*/
-	asm volatile("eieio; tlbsync; ptesync" : : : "memory");
+	if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR))
+		flush_partition(lpid, old);
 }
 
 void mmu_partition_table_set_entry(unsigned int lpid, unsigned long dw0,
-- 
2.20.1