Currently, the node_distance macro just indexes numa_slit. However,
numa_slit is not currently exported, and so node_distance cannot be used
by any modules, whether in-tree or out-of-tree. None of the in-tree
modules use it directly, but NVMe used to. Instead of exporting
numa_slit, this commit refactors the implementation to be more like x86
and arm64, by providing wrapper functions for getting and setting
distances which perform bounds-checking on the parameters, and exporting
the new __node_distance function.
Signed-off-by: James Clarke <jrtc27@xxxxxxxxxx>
---
arch/ia64/include/asm/numa.h | 13 ++++--------
arch/ia64/kernel/acpi.c | 18 +++++++++-------
arch/ia64/mm/numa.c | 50 +++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 64 insertions(+), 17 deletions(-)
diff --git a/arch/ia64/include/asm/numa.h b/arch/ia64/include/asm/numa.h
index ebef7f40aabb..43242d9283af 100644
--- a/arch/ia64/include/asm/numa.h
+++ b/arch/ia64/include/asm/numa.h
@@ -50,16 +50,11 @@ struct node_cpuid_s {
extern struct node_memblk_s node_memblk[NR_NODE_MEMBLKS];
extern struct node_cpuid_s node_cpuid[NR_CPUS];
-/*
- * ACPI 2.0 SLIT (System Locality Information Table)
- * http://devresource.hp.com/devresource/Docs/TechPapers/IA64/slit.pdf
- *
- * This is a matrix with "distances" between nodes, they should be
- * proportional to the memory access latency ratios.
- */
+extern void __init numa_reset_distance(void);
+extern void __init numa_set_distance(int from, int to, int distance);
-extern u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
-#define node_distance(from,to) (numa_slit[(from) * MAX_NUMNODES + (to)])
+extern int __node_distance(int, int);
+#define node_distance(a, b) __node_distance(a, b)
extern int paddr_to_nid(unsigned long paddr);
diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index 1d29b2f8726b..4cbc58519e25 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -571,24 +571,28 @@ void __init acpi_numa_fixup(void)
num_node_memblks);
if (!slit_table) {
- for (i = 0; i < MAX_NUMNODES; i++)
- for (j = 0; j < MAX_NUMNODES; j++)
- node_distance(i, j) = i == j ? LOCAL_DISTANCE :
- REMOTE_DISTANCE;
+ for (i = 0; i < MAX_NUMNODES; i++) {
+ for (j = 0; j < MAX_NUMNODES; j++) {
+ int dist = i == j ?
+ LOCAL_DISTANCE : REMOTE_DISTANCE;
+ numa_set_distance(i, j, dist);
+ }
+ }
return;
}
- memset(numa_slit, -1, sizeof(numa_slit));
+ numa_reset_distance();
for (i = 0; i < slit_table->locality_count; i++) {
if (!pxm_bit_test(i))
continue;
node_from = pxm_to_node(i);
for (j = 0; j < slit_table->locality_count; j++) {
+ int dist;
if (!pxm_bit_test(j))
continue;
node_to = pxm_to_node(j);
- node_distance(node_from, node_to) =
- slit_table->entry[i * slit_table->locality_count + j];
+ dist = slit_table->entry[i * slit_table->locality_count + j];
+ numa_set_distance(node_from, node_to, dist);
}
}
diff --git a/arch/ia64/mm/numa.c b/arch/ia64/mm/numa.c
index aa19b7ac8222..7c0b563ca878 100644
--- a/arch/ia64/mm/numa.c
+++ b/arch/ia64/mm/numa.c
@@ -34,7 +34,55 @@ struct node_cpuid_s node_cpuid[NR_CPUS] =
* This is a matrix with "distances" between nodes, they should be
* proportional to the memory access latency ratios.
*/
-u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
+static u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
+
+/**
+ * numa_reset_distance - Reset NUMA distance table
+ *
+ * The current table is filled with 0xFF.
+ */
+void __init numa_reset_distance(void)
+{
+ memset(numa_slit, -1, sizeof(numa_slit));
+}
+
+/**
+ * numa_set_distance - Set NUMA distance from one NUMA to another
+ * @from: the 'from' node to set distance
+ * @to: the 'to' node to set distance
+ * @distance: NUMA distance
+ *
+ * Set the distance from node @from to @to to @distance. If @from or @to is
+ * higher than the highest possible node or lower than zero, or @distance
+ * doesn't make sense, the call is ignored. This is to allow simplification of
+ * specific NUMA config implementations.
+ */
+void __init numa_set_distance(int from, int to, int distance)
+{
+ if (from >= MAX_NUMNODES || to >= MAX_NUMNODES ||
+ from < 0 || to < 0) {
+ pr_warn_once("NUMA: Warning: node ids are out of bound, from=%d to=%d distance=%d\n",
+ from, to, distance);
+ return;
+ }
+
+ if ((u8)distance != distance ||
+ (from == to && distance != LOCAL_DISTANCE)) {
+ pr_warn_once("NUMA: Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
+ from, to, distance);
+ return;
+ }
+
+ numa_slit[from * MAX_NUMNODES + to] = distance;
+}
+
+int __node_distance(int from, int to)
+{
+ if (from >= MAX_NUMNODES || to >= MAX_NUMNODES)
+ return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
+ return numa_slit[from * MAX_NUMNODES + to];
+}
+EXPORT_SYMBOL(__node_distance);
/* Identify which cnode a physical address resides on */
int
--
2.15.1
--
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