[PATCH 29/37] xen/arm: introduce a helper to parse device tree processor node

[Wei Chen <wei.chen@xxxxxxx>]

Processor NUMA ID information is stored in device tree's processor
node as "numa-node-id". We need a new helper to parse this ID from
processor node. If we get this ID from processor node, this ID's
validity still need to be checked. Once we got a invalid NUMA ID
from any processor node, the device tree will be marked as NUMA
information invalid.

Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
---
 xen/arch/arm/Makefile           |  1 +
 xen/arch/arm/numa_device_tree.c | 58 +++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+)
 create mode 100644 xen/arch/arm/numa_device_tree.c

diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index 41ca311b6b..c50df2c25d 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -36,6 +36,7 @@ obj-y += mem_access.o
 obj-y += mm.o
 obj-y += monitor.o
 obj-$(CONFIG_NUMA) += numa.o
+obj-$(CONFIG_DEVICE_TREE_NUMA) += numa_device_tree.o
 obj-y += p2m.o
 obj-y += percpu.o
 obj-y += platform.o
diff --git a/xen/arch/arm/numa_device_tree.c b/xen/arch/arm/numa_device_tree.c
new file mode 100644
index 0000000000..2428fbae0b
--- /dev/null
+++ b/xen/arch/arm/numa_device_tree.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Arm Architecture support layer for NUMA.
+ *
+ * Copyright (C) 2021 Arm Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#include <xen/init.h>
+#include <xen/nodemask.h>
+#include <xen/numa.h>
+#include <xen/libfdt/libfdt.h>
+#include <xen/device_tree.h>
+
+/* Callback for device tree processor affinity */
+static int __init fdt_numa_processor_affinity_init(nodeid_t node)
+{
+    if ( srat_disabled() )
+        return -EINVAL;
+    else if ( node == NUMA_NO_NODE || node >= MAX_NUMNODES )
+    {
+        bad_srat();
+        return -EINVAL;
+       }
+
+    numa_set_processor_nodes_parsed(node);
+    fw_numa = 1;
+
+    printk(KERN_INFO "DT: NUMA node %"PRIu8" processor parsed\n", node);
+
+    return 0;
+}
+
+/* Parse CPU NUMA node info */
+static int __init fdt_parse_numa_cpu_node(const void *fdt, int node)
+{
+    uint32_t nid;
+
+    nid = device_tree_get_u32(fdt, node, "numa-node-id", MAX_NUMNODES);
+    if ( nid >= MAX_NUMNODES )
+    {
+        printk(XENLOG_ERR "Node id %u exceeds maximum value\n", nid);
+        return -EINVAL;
+    }
+
+    return fdt_numa_processor_affinity_init(nid);
+}
-- 
2.25.1