From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>

Move code dealing with numa_distance array from arch/x86 to
mm/numa_memblks.c

This code will be later reused by arch_numa.

No functional changes.

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
 arch/x86/mm/numa.c                   | 101 ---------------------------
 arch/x86/mm/numa_internal.h          |   2 -
 include/linux/numa_memblks.h         |   4 ++
 {arch/x86/mm => mm}/numa_emulation.c |   0
 mm/numa_memblks.c                    | 101 +++++++++++++++++++++++++++
 5 files changed, 105 insertions(+), 103 deletions(-)
 rename {arch/x86/mm => mm}/numa_emulation.c (100%)

diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index 8bc0b34c6ea2..3848e68d771a 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -24,9 +24,6 @@
 
 int numa_off;
 
-static int numa_distance_cnt;
-static u8 *numa_distance;
-
 static __init int numa_setup(char *opt)
 {
 	if (!opt)
@@ -118,104 +115,6 @@ void __init setup_node_to_cpumask_map(void)
 	pr_debug("Node to cpumask map for %u nodes\n", nr_node_ids);
 }
 
-/**
- * numa_reset_distance - Reset NUMA distance table
- *
- * The current table is freed.  The next numa_set_distance() call will
- * create a new one.
- */
-void __init numa_reset_distance(void)
-{
-	size_t size = numa_distance_cnt * numa_distance_cnt * sizeof(numa_distance[0]);
-
-	if (numa_distance)
-		memblock_free(numa_distance, size);
-	numa_distance_cnt = 0;
-	numa_distance = NULL;	/* enable table creation */
-}
-
-static int __init numa_alloc_distance(void)
-{
-	nodemask_t nodes_parsed;
-	size_t size;
-	int i, j, cnt = 0;
-
-	/* size the new table and allocate it */
-	nodes_parsed = numa_nodes_parsed;
-	numa_nodemask_from_meminfo(&nodes_parsed, &numa_meminfo);
-
-	for_each_node_mask(i, nodes_parsed)
-		cnt = i;
-	cnt++;
-	size = cnt * cnt * sizeof(numa_distance[0]);
-
-	numa_distance = memblock_alloc(size, PAGE_SIZE);
-	if (!numa_distance) {
-		pr_warn("Warning: can't allocate distance table!\n");
-		return -ENOMEM;
-	}
-
-	numa_distance_cnt = cnt;
-
-	/* fill with the default distances */
-	for (i = 0; i < cnt; i++)
-		for (j = 0; j < cnt; j++)
-			numa_distance[i * cnt + j] = i == j ?
-				LOCAL_DISTANCE : REMOTE_DISTANCE;
-	printk(KERN_DEBUG "NUMA: Initialized distance table, cnt=%d\n", cnt);
-
-	return 0;
-}
-
-/**
- * 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 distance table
- * doesn't exist, one which is large enough to accommodate all the currently
- * known nodes will be created.
- *
- * If such table cannot be allocated, a warning is printed and further
- * calls are ignored until the distance table is reset with
- * numa_reset_distance().
- *
- * If @from or @to is higher than the highest known node or lower than zero
- * at the time of table creation 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 (!numa_distance && numa_alloc_distance() < 0)
-		return;
-
-	if (from >= numa_distance_cnt || to >= numa_distance_cnt ||
-			from < 0 || to < 0) {
-		pr_warn_once("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("Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
-			     from, to, distance);
-		return;
-	}
-
-	numa_distance[from * numa_distance_cnt + to] = distance;
-}
-
-int __node_distance(int from, int to)
-{
-	if (from >= numa_distance_cnt || to >= numa_distance_cnt)
-		return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
-	return numa_distance[from * numa_distance_cnt + to];
-}
-EXPORT_SYMBOL(__node_distance);
-
 static int __init numa_register_memblks(struct numa_meminfo *mi)
 {
 	int i, nid, err;
diff --git a/arch/x86/mm/numa_internal.h b/arch/x86/mm/numa_internal.h
index a51229a2f5af..249e3aaeadce 100644
--- a/arch/x86/mm/numa_internal.h
+++ b/arch/x86/mm/numa_internal.h
@@ -5,8 +5,6 @@
 #include <linux/types.h>
 #include <asm/numa.h>
 
-void __init numa_reset_distance(void);
-
 void __init x86_numa_init(void);
 
 struct numa_meminfo;
diff --git a/include/linux/numa_memblks.h b/include/linux/numa_memblks.h
index 6981cf97d2c9..968a590535ac 100644
--- a/include/linux/numa_memblks.h
+++ b/include/linux/numa_memblks.h
@@ -7,6 +7,10 @@
 
 #define NR_NODE_MEMBLKS		(MAX_NUMNODES * 2)
 
+extern int numa_distance_cnt;
+void __init numa_set_distance(int from, int to, int distance);
+void __init numa_reset_distance(void);
+
 struct numa_memblk {
 	u64			start;
 	u64			end;
diff --git a/arch/x86/mm/numa_emulation.c b/mm/numa_emulation.c
similarity index 100%
rename from arch/x86/mm/numa_emulation.c
rename to mm/numa_emulation.c
diff --git a/mm/numa_memblks.c b/mm/numa_memblks.c
index e31307317ca7..e0039549aaac 100644
--- a/mm/numa_memblks.c
+++ b/mm/numa_memblks.c
@@ -7,11 +7,112 @@
 #include <linux/numa.h>
 #include <linux/numa_memblks.h>
 
+int numa_distance_cnt;
+static u8 *numa_distance;
+
 nodemask_t numa_nodes_parsed __initdata;
 
 struct numa_meminfo numa_meminfo __initdata_or_meminfo;
 struct numa_meminfo numa_reserved_meminfo __initdata_or_meminfo;
 
+/**
+ * numa_reset_distance - Reset NUMA distance table
+ *
+ * The current table is freed.  The next numa_set_distance() call will
+ * create a new one.
+ */
+void __init numa_reset_distance(void)
+{
+	size_t size = numa_distance_cnt * numa_distance_cnt * sizeof(numa_distance[0]);
+
+	if (numa_distance)
+		memblock_free(numa_distance, size);
+	numa_distance_cnt = 0;
+	numa_distance = NULL;	/* enable table creation */
+}
+
+static int __init numa_alloc_distance(void)
+{
+	nodemask_t nodes_parsed;
+	size_t size;
+	int i, j, cnt = 0;
+
+	/* size the new table and allocate it */
+	nodes_parsed = numa_nodes_parsed;
+	numa_nodemask_from_meminfo(&nodes_parsed, &numa_meminfo);
+
+	for_each_node_mask(i, nodes_parsed)
+		cnt = i;
+	cnt++;
+	size = cnt * cnt * sizeof(numa_distance[0]);
+
+	numa_distance = memblock_alloc(size, PAGE_SIZE);
+	if (!numa_distance) {
+		pr_warn("Warning: can't allocate distance table!\n");
+		return -ENOMEM;
+	}
+
+	numa_distance_cnt = cnt;
+
+	/* fill with the default distances */
+	for (i = 0; i < cnt; i++)
+		for (j = 0; j < cnt; j++)
+			numa_distance[i * cnt + j] = i == j ?
+				LOCAL_DISTANCE : REMOTE_DISTANCE;
+	printk(KERN_DEBUG "NUMA: Initialized distance table, cnt=%d\n", cnt);
+
+	return 0;
+}
+
+/**
+ * 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 distance table
+ * doesn't exist, one which is large enough to accommodate all the currently
+ * known nodes will be created.
+ *
+ * If such table cannot be allocated, a warning is printed and further
+ * calls are ignored until the distance table is reset with
+ * numa_reset_distance().
+ *
+ * If @from or @to is higher than the highest known node or lower than zero
+ * at the time of table creation 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 (!numa_distance && numa_alloc_distance() < 0)
+		return;
+
+	if (from >= numa_distance_cnt || to >= numa_distance_cnt ||
+			from < 0 || to < 0) {
+		pr_warn_once("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("Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
+			     from, to, distance);
+		return;
+	}
+
+	numa_distance[from * numa_distance_cnt + to] = distance;
+}
+
+int __node_distance(int from, int to)
+{
+	if (from >= numa_distance_cnt || to >= numa_distance_cnt)
+		return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
+	return numa_distance[from * numa_distance_cnt + to];
+}
+EXPORT_SYMBOL(__node_distance);
+
 static int __init numa_add_memblk_to(int nid, u64 start, u64 end,
 				     struct numa_meminfo *mi)
 {
-- 
2.43.0

On Tue, 16 Jul 2024 14:13:42 +0300
Mike Rapoport <rppt@kernel.org> wrote:

> From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
> 
> Move code dealing with numa_distance array from arch/x86 to
> mm/numa_memblks.c

It's not really numa memblock related. Is this the best place
to put it?

> 
> This code will be later reused by arch_numa.
> 
> No functional changes.
> 
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

On Fri, Jul 19, 2024 at 06:48:42PM +0100, Jonathan Cameron wrote:
> On Tue, 16 Jul 2024 14:13:42 +0300
> Mike Rapoport <rppt@kernel.org> wrote:
> 
> > From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
> > 
> > Move code dealing with numa_distance array from arch/x86 to
> > mm/numa_memblks.c
> 
> It's not really numa memblock related. Is this the best place
> to put it?

There is a dependency of numa_alloc_distance() on
numa_nodemask_from_meminfo() that relies on numa_memblk but I agree that
they are not really related.

However, I'd prefer to keep this code in mm/numa_memblks.c because
node_distance() definitions and related code are different between
architecures and having this code outside numa_memblks in e.g
mm/numa.c would be way more involved.
 
> > This code will be later reused by arch_numa.
> > 
> > No functional changes.
> > 
> > Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> 

-- 
Sincerely yours,
Mike.

On 2024-07-16 6:13 AM, Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
> 
> Move code dealing with numa_distance array from arch/x86 to
> mm/numa_memblks.c
> 
> This code will be later reused by arch_numa.
> 
> No functional changes.
> 
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> ---
>  arch/x86/mm/numa.c                   | 101 ---------------------------
>  arch/x86/mm/numa_internal.h          |   2 -
>  include/linux/numa_memblks.h         |   4 ++
>  {arch/x86/mm => mm}/numa_emulation.c |   0
>  mm/numa_memblks.c                    | 101 +++++++++++++++++++++++++++
>  5 files changed, 105 insertions(+), 103 deletions(-)
>  rename {arch/x86/mm => mm}/numa_emulation.c (100%)

The numa_emulation.c rename looks like it should be part of the next commit, not
this one.

On Thu, Jul 18, 2024 at 04:46:17PM -0500, Samuel Holland wrote:
> On 2024-07-16 6:13 AM, Mike Rapoport wrote:
> > From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
> > 
> > Move code dealing with numa_distance array from arch/x86 to
> > mm/numa_memblks.c
> > 
> > This code will be later reused by arch_numa.
> > 
> > No functional changes.
> > 
> > Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> > ---
> >  arch/x86/mm/numa.c                   | 101 ---------------------------
> >  arch/x86/mm/numa_internal.h          |   2 -
> >  include/linux/numa_memblks.h         |   4 ++
> >  {arch/x86/mm => mm}/numa_emulation.c |   0
> >  mm/numa_memblks.c                    | 101 +++++++++++++++++++++++++++
> >  5 files changed, 105 insertions(+), 103 deletions(-)
> >  rename {arch/x86/mm => mm}/numa_emulation.c (100%)
> 
> The numa_emulation.c rename looks like it should be part of the next commit, not
> this one.

Right, thanks!

-- 
Sincerely yours,
Mike.