From: Yuquan Wang <wangyuquan1236@phytium.com.cn>
Date: Thu, 8 May 2025 02:27:19 +0000 (+0800)
Subject: mm: numa_memblks: introduce numa_add_reserved_memblk
X-Git-Tag: v6.16-rc1~92^2~41
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3f12680913fda8de06c21e836dd5f246fe1684e5;p=thirdparty%2Flinux.git

mm: numa_memblks: introduce numa_add_reserved_memblk

acpi_parse_cfmws() currently adds empty CFMWS ranges to numa_meminfo with
the expectation that numa_cleanup_meminfo moves them to
numa_reserved_meminfo.  There is no need for that indirection when it is
known in advance that these unpopulated ranges are meant for
numa_reserved_meminfo in support of future hotplug / CXL provisioning.

Introduce and use numa_add_reserved_memblk() to add the empty CFMWS ranges
directly.

Link: https://lkml.kernel.org/r/20250508022719.3941335-1-wangyuquan1236@phytium.com.cn
Signed-off-by: Yuquan Wang <wangyuquan1236@phytium.com.cn>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Cc: Bruno Faccini <bfaccini@nvidia.com>
Cc: Chen Baozi <chenbaozi@phytium.com.cn>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Haibo Xu <haibo1.xu@intel.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Robert Richter <rrichter@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
index 5d0cbc5c88a01..53816dfab6452 100644
--- a/drivers/acpi/numa/srat.c
+++ b/drivers/acpi/numa/srat.c
@@ -464,7 +464,7 @@ static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
 		return -EINVAL;
 	}
 
-	if (numa_add_memblk(node, start, end) < 0) {
+	if (numa_add_reserved_memblk(node, start, end) < 0) {
 		/* CXL driver must handle the NUMA_NO_NODE case */
 		pr_warn("ACPI NUMA: Failed to add memblk for CFMWS node %d [mem %#llx-%#llx]\n",
 			node, start, end);
diff --git a/include/linux/numa_memblks.h b/include/linux/numa_memblks.h
index dd85613cdd86a..991076cba7c50 100644
--- a/include/linux/numa_memblks.h
+++ b/include/linux/numa_memblks.h
@@ -22,6 +22,7 @@ struct numa_meminfo {
 };
 
 int __init numa_add_memblk(int nodeid, u64 start, u64 end);
+int __init numa_add_reserved_memblk(int nid, u64 start, u64 end);
 void __init numa_remove_memblk_from(int idx, struct numa_meminfo *mi);
 
 int __init numa_cleanup_meminfo(struct numa_meminfo *mi);
diff --git a/mm/numa_memblks.c b/mm/numa_memblks.c
index ff4054f4334da..541a99c4071a6 100644
--- a/mm/numa_memblks.c
+++ b/mm/numa_memblks.c
@@ -200,6 +200,28 @@ int __init numa_add_memblk(int nid, u64 start, u64 end)
 	return numa_add_memblk_to(nid, start, end, &numa_meminfo);
 }
 
+/**
+ * numa_add_reserved_memblk - Add one numa_memblk to numa_reserved_meminfo
+ * @nid: NUMA node ID of the new memblk
+ * @start: Start address of the new memblk
+ * @end: End address of the new memblk
+ *
+ * Add a new memblk to the numa_reserved_meminfo.
+ *
+ * Usage Case: numa_cleanup_meminfo() reconciles all numa_memblk instances
+ * against memblock_type information and moves any that intersect reserved
+ * ranges to numa_reserved_meminfo. However, when that information is known
+ * ahead of time, we use numa_add_reserved_memblk() to add the numa_memblk
+ * to numa_reserved_meminfo directly.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int __init numa_add_reserved_memblk(int nid, u64 start, u64 end)
+{
+	return numa_add_memblk_to(nid, start, end, &numa_reserved_meminfo);
+}
+
 /**
  * numa_cleanup_meminfo - Cleanup a numa_meminfo
  * @mi: numa_meminfo to clean up