1 files changed, 141 insertions, 1 deletions

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 86d6cd92ce3d..6f4097680580 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -17,6 +17,7 @@
 #include <linux/nodemask.h>
 #include <linux/cpu.h>
 #include <linux/device.h>
+#include <linux/pm_runtime.h>
 #include <linux/swap.h>
 #include <linux/slab.h>
 
@@ -59,6 +60,94 @@ static inline ssize_t node_read_cpulist(struct device *dev,
 static DEVICE_ATTR(cpumap,  S_IRUGO, node_read_cpumask, NULL);
 static DEVICE_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);
 
+/**
+ * struct node_access_nodes - Access class device to hold user visible
+ * 			      relationships to other nodes.
+ * @dev:	Device for this memory access class
+ * @list_node:	List element in the node's access list
+ * @access:	The access class rank
+ */
+struct node_access_nodes {
+	struct device		dev;
+	struct list_head	list_node;
+	unsigned		access;
+};
+#define to_access_nodes(dev) container_of(dev, struct node_access_nodes, dev)
+
+static struct attribute *node_init_access_node_attrs[] = {
+	NULL,
+};
+
+static struct attribute *node_targ_access_node_attrs[] = {
+	NULL,
+};
+
+static const struct attribute_group initiators = {
+	.name	= "initiators",
+	.attrs	= node_init_access_node_attrs,
+};
+
+static const struct attribute_group targets = {
+	.name	= "targets",
+	.attrs	= node_targ_access_node_attrs,
+};
+
+static const struct attribute_group *node_access_node_groups[] = {
+	&initiators,
+	&targets,
+	NULL,
+};
+
+static void node_remove_accesses(struct node *node)
+{
+	struct node_access_nodes *c, *cnext;
+
+	list_for_each_entry_safe(c, cnext, &node->access_list, list_node) {
+		list_del(&c->list_node);
+		device_unregister(&c->dev);
+	}
+}
+
+static void node_access_release(struct device *dev)
+{
+	kfree(to_access_nodes(dev));
+}
+
+static struct node_access_nodes *node_init_node_access(struct node *node,
+						       unsigned access)
+{
+	struct node_access_nodes *access_node;
+	struct device *dev;
+
+	list_for_each_entry(access_node, &node->access_list, list_node)
+		if (access_node->access == access)
+			return access_node;
+
+	access_node = kzalloc(sizeof(*access_node), GFP_KERNEL);
+	if (!access_node)
+		return NULL;
+
+	access_node->access = access;
+	dev = &access_node->dev;
+	dev->parent = &node->dev;
+	dev->release = node_access_release;
+	dev->groups = node_access_node_groups;
+	if (dev_set_name(dev, "access%u", access))
+		goto free;
+
+	if (device_register(dev))
+		goto free_name;
+
+	pm_runtime_no_callbacks(dev);
+	list_add_tail(&access_node->list_node, &node->access_list);
+	return access_node;
+free_name:
+	kfree_const(dev->kobj.name);
+free:
+	kfree(access_node);
+	return NULL;
+}
+
 #define K(x) ((x) << (PAGE_SHIFT - 10))
 static ssize_t node_read_meminfo(struct device *dev,
 			struct device_attribute *attr, char *buf)
@@ -340,7 +429,7 @@ static int register_node(struct node *node, int num)
 void unregister_node(struct node *node)
 {
 	hugetlb_unregister_node(node);		/* no-op, if memoryless node */
-
+	node_remove_accesses(node);
 	device_unregister(&node->dev);
 }
 
@@ -372,6 +461,56 @@ int register_cpu_under_node(unsigned int cpu, unsigned int nid)
 				 kobject_name(&node_devices[nid]->dev.kobj));
 }
 
+/**
+ * register_memory_node_under_compute_node - link memory node to its compute
+ *					     node for a given access class.
+ * @mem_node:	Memory node number
+ * @cpu_node:	Cpu  node number
+ * @access:	Access class to register
+ *
+ * Description:
+ * 	For use with platforms that may have separate memory and compute nodes.
+ * 	This function will export node relationships linking which memory
+ * 	initiator nodes can access memory targets at a given ranked access
+ * 	class.
+ */
+int register_memory_node_under_compute_node(unsigned int mem_nid,
+					    unsigned int cpu_nid,
+					    unsigned access)
+{
+	struct node *init_node, *targ_node;
+	struct node_access_nodes *initiator, *target;
+	int ret;
+
+	if (!node_online(cpu_nid) || !node_online(mem_nid))
+		return -ENODEV;
+
+	init_node = node_devices[cpu_nid];
+	targ_node = node_devices[mem_nid];
+	initiator = node_init_node_access(init_node, access);
+	target = node_init_node_access(targ_node, access);
+	if (!initiator || !target)
+		return -ENOMEM;
+
+	ret = sysfs_add_link_to_group(&initiator->dev.kobj, "targets",
+				      &targ_node->dev.kobj,
+				      dev_name(&targ_node->dev));
+	if (ret)
+		return ret;
+
+	ret = sysfs_add_link_to_group(&target->dev.kobj, "initiators",
+				      &init_node->dev.kobj,
+				      dev_name(&init_node->dev));
+	if (ret)
+		goto err;
+
+	return 0;
+ err:
+	sysfs_remove_link_from_group(&initiator->dev.kobj, "targets",
+				     dev_name(&targ_node->dev));
+	return ret;
+}
+
 int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
 {
 	struct device *obj;
@@ -580,6 +719,7 @@ int __register_one_node(int nid)
 			register_cpu_under_node(cpu, nid);
 	}
 
+	INIT_LIST_HEAD(&node_devices[nid]->access_list);
 	/* initialize work queue for memory hot plug */
 	init_node_hugetlb_work(nid);