[PATCH v10 3/8] dt, numa: adding numa dt binding implementation.

[Ganapatrao Kulkarni]

dt node parsing for numa topology is done using device property
numa-node-id and device node distance-map.

Reviewed-by: Robert Richter <rrichter@xxxxxxxxxx>
Signed-off-by: Ganapatrao Kulkarni <gkulkarni@xxxxxxxxxxxxxxxxxx>
---
 drivers/of/Kconfig   |  11 +++
 drivers/of/Makefile  |   1 +
 drivers/of/of_numa.c | 207 +++++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/of.h   |   4 +
 4 files changed, 223 insertions(+)
 create mode 100644 drivers/of/of_numa.c

diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index e2a4841..8f9cc3a 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -112,4 +112,15 @@ config OF_OVERLAY
 	  While this option is selected automatically when needed, you can
 	  enable it manually to improve device tree unit test coverage.
 
+config OF_NUMA
+	bool "Device Tree NUMA support"
+	depends on NUMA
+	depends on OF
+	depends on ARM64
+	default y
+	help
+	  Enable Device Tree NUMA support.
+	  This enables the numa mapping of cpu, memory, io and
+	  inter node distances using dt bindings.
+
 endif # OF
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index 156c072..bee3fa9 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -14,5 +14,6 @@ obj-$(CONFIG_OF_MTD)	+= of_mtd.o
 obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
 obj-$(CONFIG_OF_RESOLVE)  += resolver.o
 obj-$(CONFIG_OF_OVERLAY) += overlay.o
+obj-$(CONFIG_OF_NUMA) += of_numa.o
 
 obj-$(CONFIG_OF_UNITTEST) += unittest-data/
diff --git a/drivers/of/of_numa.c b/drivers/of/of_numa.c
new file mode 100644
index 0000000..1142cdb
--- /dev/null
+++ b/drivers/of/of_numa.c
@@ -0,0 +1,207 @@
+/*
+ * OF NUMA Parsing support.
+ *
+ * Copyright (C) 2015 Cavium Inc.
+ * Author: Ganapatrao Kulkarni <gkulkarni@xxxxxxxxxx>
+ *
+ * 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 <linux/of.h>
+#include <linux/of_fdt.h>
+
+/* define default numa node to 0 */
+#define DEFAULT_NODE 0
+
+/* Returns nid in the range [0..MAX_NUMNODES-1],
+ * or NUMA_NO_NODE if no valid numa-node-id entry found
+ * or DEFAULT_NODE if no numa-node-id entry exists
+ */
+static int of_numa_prop_to_nid(const __be32 *of_numa_prop, int length)
+{
+	int nid;
+
+	if (!of_numa_prop)
+		return DEFAULT_NODE;
+
+	if (length != sizeof(*of_numa_prop)) {
+		pr_warn("NUMA: Invalid of_numa_prop length %d found.\n",
+				length);
+		return NUMA_NO_NODE;
+	}
+
+	nid = of_read_number(of_numa_prop, 1);
+	if (nid >= MAX_NUMNODES) {
+		pr_warn("NUMA: Invalid numa node %d found.\n", nid);
+		return NUMA_NO_NODE;
+	}
+
+	return nid;
+}
+
+static int __init early_init_of_node_to_nid(unsigned long node)
+{
+	int length;
+	const __be32 *of_numa_prop;
+
+	of_numa_prop = of_get_flat_dt_prop(node, "numa-node-id", &length);
+
+	return of_numa_prop_to_nid(of_numa_prop, length);
+}
+
+/*
+ * Even though we connect cpus to numa domains later in SMP
+ * init, we need to know the node ids now for all cpus.
+*/
+static int __init early_init_parse_cpu_node(unsigned long node)
+{
+	int nid;
+	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+
+	if (type == NULL)
+		return 0;
+
+	if (strcmp(type, "cpu") != 0)
+		return 0;
+
+	nid = early_init_of_node_to_nid(node);
+	if (nid == NUMA_NO_NODE)
+		return -EINVAL;
+
+	node_set(nid, numa_nodes_parsed);
+	return 0;
+}
+
+static int __init early_init_parse_memory_node(unsigned long node)
+{
+	const __be32 *reg, *endp;
+	int length;
+	int nid;
+	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+
+	if (type == NULL)
+		return 0;
+
+	if (strcmp(type, "memory") != 0)
+		return 0;
+
+	nid = early_init_of_node_to_nid(node);
+	if (nid == NUMA_NO_NODE)
+		return -EINVAL;
+
+	reg = of_get_flat_dt_prop(node, "reg", &length);
+	endp = reg + (length / sizeof(__be32));
+
+	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
+		u64 base, size;
+
+		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
+		size = dt_mem_next_cell(dt_root_size_cells, &reg);
+		pr_debug("NUMA:  base = %llx , node = %u\n",
+				base, nid);
+
+		if (numa_add_memblk(nid, base, size) < 0)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int __init early_init_parse_distance_map_v1(unsigned long node,
+		const char *uname)
+{
+	const __be32 *prop_dist_matrix;
+	int length = 0, i, matrix_count;
+	int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+
+	pr_info("NUMA: parsing numa-distance-map-v1\n");
+
+	prop_dist_matrix =
+		of_get_flat_dt_prop(node, "distance-matrix", &length);
+
+	if (!length) {
+		pr_err("NUMA: failed to parse distance-matrix\n");
+		return -ENODEV;
+	}
+
+	matrix_count = ((length / sizeof(__be32)) / (3 * nr_size_cells));
+
+	if ((matrix_count * sizeof(__be32) * 3 * nr_size_cells) !=  length) {
+		pr_warn("NUMA: invalid distance-matrix length %d\n", length);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < matrix_count; i++) {
+		u32 nodea, nodeb, distance;
+
+		nodea = dt_mem_next_cell(nr_size_cells, &prop_dist_matrix);
+		nodeb = dt_mem_next_cell(nr_size_cells, &prop_dist_matrix);
+		distance = dt_mem_next_cell(nr_size_cells, &prop_dist_matrix);
+		numa_set_distance(nodea, nodeb, distance);
+		pr_debug("NUMA:  distance[node%d -> node%d] = %d\n",
+				nodea, nodeb, distance);
+
+		/* Set default distance of node B->A same as A->B */
+		if (nodeb > nodea)
+			numa_set_distance(nodeb, nodea, distance);
+	}
+
+	return 0;
+}
+
+static int __init early_init_parse_distance_map(unsigned long node,
+		const char *uname)
+{
+	if (strcmp(uname, "distance-map") != 0)
+		return 0;
+
+	if (of_flat_dt_is_compatible(node, "numa-distance-map-v1"))
+		return early_init_parse_distance_map_v1(node, uname);
+
+	pr_err("NUMA: invalid distance-map device node\n");
+	return -EINVAL;
+}
+
+static int __init early_init_of_scan_numa_map(unsigned long node, const char *uname,
+				     int depth, void *data)
+{
+	int ret;
+
+	ret = early_init_parse_cpu_node(node);
+	if (ret)
+		return ret;
+
+	ret = early_init_parse_memory_node(node);
+	if (ret)
+		return ret;
+
+	return early_init_parse_distance_map(node, uname);
+}
+
+int of_node_to_nid(struct device_node *device)
+{
+	const __be32 *of_numa_prop;
+	int length;
+
+	of_numa_prop = of_get_property(device, "numa-node-id", &length);
+	if (of_numa_prop)
+		return of_numa_prop_to_nid(of_numa_prop, length);
+
+	return NUMA_NO_NODE;
+}
+
+/* DT node mapping is done already early_init_of_scan_memory */
+int __init of_numa_init(void)
+{
+	return of_scan_flat_dt(early_init_of_scan_numa_map, NULL);
+}
diff --git a/include/linux/of.h b/include/linux/of.h
index dd10626..23e5bad 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -685,6 +685,10 @@ static inline int of_node_to_nid(struct device_node *device)
 }
 #endif
 
+#ifdef CONFIG_OF_NUMA
+extern int __init of_numa_init(void);
+#endif
+
 static inline struct device_node *of_find_matching_node(
 	struct device_node *from,
 	const struct of_device_id *matches)
-- 
1.8.1.4