powerpc/64: Make type of partition table flush depend on partition type

paulusmack · mpe · commit 16ed141677c5 · 2017-01-31T19:11:46.000+11:00
When changing a partition table entry on POWER9, we do a particular
form of the tlbie instruction which flushes all TLBs and caches of
the partition table for a given logical partition ID (LPID).
This instruction has a field in the instruction word, labelled R
(radix), which should be 1 if the partition was previously a radix
partition and 0 if it was a HPT partition.  This implements that
logic.

Signed-off-by: Paul Mackerras &lt;paulus@ozlabs.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
@@ -454,13 +454,23 @@ void __init mmu_partition_table_init(void)
 void mmu_partition_table_set_entry(unsigned int lpid, unsigned long dw0,
 				   unsigned long dw1)
 {
+	unsigned long old = be64_to_cpu(partition_tb[lpid].patb0);
+
 	partition_tb[lpid].patb0 = cpu_to_be64(dw0);
 	partition_tb[lpid].patb1 = cpu_to_be64(dw1);
 
-	/* Global flush of TLBs and partition table caches for this lpid */
+	/*
+	 * Global flush of TLBs and partition table caches for this 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");
-	asm volatile(PPC_TLBIE_5(%0,%1,2,0,0) : :
-		     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
+	if (old & PATB_HR)
+		asm volatile(PPC_TLBIE_5(%0,%1,2,0,1) : :
+			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
+	else
+		asm volatile(PPC_TLBIE_5(%0,%1,2,0,0) : :
+			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
 	asm volatile("eieio; tlbsync; ptesync" : : : "memory");
 }
 EXPORT_SYMBOL_GPL(mmu_partition_table_set_entry);
