Hi Wei,
On 11/08/2021 11:24, Wei Chen wrote:
A NUMA aware device tree will provide a "distance-map" node to
describe distance between any two nodes. This patch introduce a
s/introduce/introduces/
new helper to parse this distance map.
Signed-off-by: Wei Chen <wei.c...@arm.com>
---
xen/arch/arm/numa_device_tree.c | 67 +++++++++++++++++++++++++++++++++
1 file changed, 67 insertions(+)
diff --git a/xen/arch/arm/numa_device_tree.c b/xen/arch/arm/numa_device_tree.c
index bbe081dcd1..6e0d1d3d9f 100644
--- a/xen/arch/arm/numa_device_tree.c
+++ b/xen/arch/arm/numa_device_tree.c
@@ -200,3 +200,70 @@ device_tree_parse_numa_memory_node(const void *fdt, int
node,
return 0;
}
+
+/* Parse NUMA distance map v1 */
+int __init
+device_tree_parse_numa_distance_map_v1(const void *fdt, int node)
+{
+ const struct fdt_property *prop;
+ const __be32 *matrix;
+ int entry_count, len, i;
entry_count and i should be unsigned. len unfortunately can't because
fdt_get_property expects a signed int.
+
+ printk(XENLOG_INFO "NUMA: parsing numa-distance-map\n");
+
+ prop = fdt_get_property(fdt, node, "distance-matrix", &len);
+ if ( !prop )
+ {
+ printk(XENLOG_WARNING
+ "NUMA: No distance-matrix property in distance-map\n");
+
+ return -EINVAL;
+ }
+
+ if ( len % sizeof(uint32_t) != 0 )
+ {
+ printk(XENLOG_WARNING
+ "distance-matrix in node is not a multiple of u32\n");
+ return -EINVAL;
+ }
+
+ entry_count = len / sizeof(uint32_t);
+ if ( entry_count <= 0 )
I understand that entry_count may be 0. But I can't see how it can be
negative as the property len cannot be (even if it is a signed type). So
I think this wants to be "== 0".
+ {
+ printk(XENLOG_WARNING "NUMA: Invalid distance-matrix\n");
+
+ return -EINVAL;
+ }
+
+ matrix = (const __be32 *)prop->data;
+ for ( i = 0; i + 2 < entry_count; i += 3 )
+ {
+ uint32_t from, to, distance;
+
+ from = dt_read_number(matrix, 1);
+ matrix++;
You can use dt_next_cell() which will update the pointer for you.
+ to = dt_read_number(matrix, 1);
+ matrix++;
+ distance = dt_read_number(matrix, 1);
+ matrix++;
+
+ if ( (from == to && distance != NUMA_LOCAL_DISTANCE) ||
+ (from != to && distance <= NUMA_LOCAL_DISTANCE) )
+ {
+ printk(XENLOG_WARNING
+ "Invalid nodes' distance from node#%d to node#%d = %d\n",
+ from, to, distance);
+ return -EINVAL;
+ }
+
+ printk(XENLOG_INFO "NUMA: distance from node#%d to node#%d = %d\n",
+ from, to, distance);
+ numa_set_distance(from, to, distance);
+
+ /* Set default distance of node B->A same as A->B */
+ if (to > from)
+ numa_set_distance(to, from, distance);
+ }
+
+ return 0;
+}
Cheers,
--
Julien Grall
