[RFC PATCH] powerpc/numa: initialize distance lookup table from drconf path

Nikunj A Dadhania
2015-06-10T04:50:44Z

Node distance will not get initialized in certain cases as
dynamic-reconfiguration path does not initialize the lookup table.

There is an assumption about the associativity list in
initialize_distance_lookup_table(). Associativity list has two forms:

a) [cpu,memory]@x/ibm,associativity has following
format:

<N> <N integers>

b) ibm,dynamic-reconfiguration-memory/ibm,associativity-lookup-arrays

<M> <N> <M*N integers>
M = the number of associativity lists
N = the number of entries per associativity list

Fix initialize_distance_lookup_table() so that it does not assume
"case a". And update the caller to skip the length field before
sending the associativity list.

Call initialize_distance_lookup_table() from drconf path with
appropriate associativity list.

Reported-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
---
arch/powerpc/mm/numa.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 5e80621..8b9502a 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -225,7 +225,7 @@ static void initialize_distance_lookup_table(int nid,
for (i = 0; i < distance_ref_points_depth; i++) {
const __be32 *entry;

- entry = &associativity[be32_to_cpu(distance_ref_points[i])];
+ entry = &associativity[be32_to_cpu(distance_ref_points[i]) - 1];
distance_lookup_table[nid][i] = of_read_number(entry, 1);
}
}
@@ -248,8 +248,12 @@ static int associativity_to_nid(const __be32 *associativity)
nid = -1;

if (nid > 0 &&
- of_read_number(associativity, 1) >= distance_ref_points_depth)
- initialize_distance_lookup_table(nid, associativity);
+ of_read_number(associativity, 1) >= distance_ref_points_depth) {
+ /*
+ * Skip the length field and send start of associativity array
+ */
+ initialize_distance_lookup_table(nid, associativity + 1);
+ }

out:
return nid;
@@ -507,6 +511,12 @@ static int of_drconf_to_nid_single(struct of_drconf_cell *drmem,

if (nid == 0xffff || nid >= MAX_NUMNODES)
nid = default_nid;
+
+ if (nid > 0) {
+ index = drmem->aa_index * aa->array_sz;
+ initialize_distance_lookup_table(nid,
+ &aa->arrays[index]);
+ }
}

return nid;
--
1.8.3.1