[PATCH 2/3] powerpc/vphn: simplify the parsing code

[Greg Kurz <gkurz@linux.vnet.ibm.com>]

According to PAPR+ 14.11.6.1 H_HOME_NODE_ASSOCIATIVITY, the hypervisor is
supposed to pack significant fields first and fill the remaining unused
fields with "all ones". It means that the first unused field can be viewed
as an end-of-list marker.
The "ibm,associativity" property in the DT isn't padded with ones and no
code in arch/powerpc/mm/numa.c seems to expect the associativity array
to be padded either.

This patch simply ends the parsing when we reach the first unused field.

Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
---
 arch/powerpc/mm/numa.c |   20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 1425517..e30c469 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -1417,7 +1417,7 @@ static int update_cpu_associativity_changes_mask(void)
  */
 static int vphn_unpack_associativity(const long *packed, __be32 *unpacked)
 {
-	int i, nr_assoc_doms = 0;
+	int i;
 	const __be16 *field = (const __be16 *) packed;
 
 #define VPHN_FIELD_UNUSED	(0xffff)
@@ -1425,33 +1425,29 @@ static int vphn_unpack_associativity(const long *packed, __be32 *unpacked)
 #define VPHN_FIELD_MASK		(~VPHN_FIELD_MSB)
 
 	for (i = 1; i < VPHN_ASSOC_BUFSIZE; i++) {
-		if (be16_to_cpup(field) == VPHN_FIELD_UNUSED) {
-			/* All significant fields processed, and remaining
-			 * fields contain the reserved value of all 1's.
-			 * Just store them.
+		if (be16_to_cpup(field) == VPHN_FIELD_UNUSED)
+			/* All significant fields processed.
 			 */
-			unpacked[i] = *((__be32 *)field);
-			field += 2;
-		} else if (be16_to_cpup(field) & VPHN_FIELD_MSB) {
+			break;
+
+		if (be16_to_cpup(field) & VPHN_FIELD_MSB) {
 			/* Data is in the lower 15 bits of this field */
 			unpacked[i] = cpu_to_be32(
 				be16_to_cpup(field) & VPHN_FIELD_MASK);
 			field++;
-			nr_assoc_doms++;
 		} else {
 			/* Data is in the lower 15 bits of this field
 			 * concatenated with the next 16 bit field
 			 */
 			unpacked[i] = *((__be32 *)field);
 			field += 2;
-			nr_assoc_doms++;
 		}
 	}
 
 	/* The first cell contains the length of the property */
-	unpacked[0] = cpu_to_be32(nr_assoc_doms);
+	unpacked[0] = cpu_to_be32(i - 1);
 
-	return nr_assoc_doms;
+	return i - 1;
 }
 
 /*