Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1473 insertions, 0 deletions

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
new file mode 100644
index 0000000000..f6c4ace3b2
--- /dev/null
+++ b/arch/powerpc/mm/numa.c
@@ -0,0 +1,1473 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * pSeries NUMA support
+ *
+ * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
+ */
+#define pr_fmt(fmt) "numa: " fmt
+
+#include <linux/threads.h>
+#include <linux/memblock.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/mmzone.h>
+#include <linux/export.h>
+#include <linux/nodemask.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/pfn.h>
+#include <linux/cpuset.h>
+#include <linux/node.h>
+#include <linux/stop_machine.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <asm/cputhreads.h>
+#include <asm/sparsemem.h>
+#include <asm/smp.h>
+#include <asm/topology.h>
+#include <asm/firmware.h>
+#include <asm/paca.h>
+#include <asm/hvcall.h>
+#include <asm/setup.h>
+#include <asm/vdso.h>
+#include <asm/vphn.h>
+#include <asm/drmem.h>
+
+static int numa_enabled = 1;
+
+static char *cmdline __initdata;
+
+int numa_cpu_lookup_table[NR_CPUS];
+cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
+struct pglist_data *node_data[MAX_NUMNODES];
+
+EXPORT_SYMBOL(numa_cpu_lookup_table);
+EXPORT_SYMBOL(node_to_cpumask_map);
+EXPORT_SYMBOL(node_data);
+
+static int primary_domain_index;
+static int n_mem_addr_cells, n_mem_size_cells;
+
+#define FORM0_AFFINITY 0
+#define FORM1_AFFINITY 1
+#define FORM2_AFFINITY 2
+static int affinity_form;
+
+#define MAX_DISTANCE_REF_POINTS 4
+static int distance_ref_points_depth;
+static const __be32 *distance_ref_points;
+static int distance_lookup_table[MAX_NUMNODES][MAX_DISTANCE_REF_POINTS];
+static int numa_distance_table[MAX_NUMNODES][MAX_NUMNODES] = {
+	[0 ... MAX_NUMNODES - 1] = { [0 ... MAX_NUMNODES - 1] = -1 }
+};
+static int numa_id_index_table[MAX_NUMNODES] = { [0 ... MAX_NUMNODES - 1] = NUMA_NO_NODE };
+
+/*
+ * Allocate node_to_cpumask_map based on number of available nodes
+ * Requires node_possible_map to be valid.
+ *
+ * Note: cpumask_of_node() is not valid until after this is done.
+ */
+static void __init setup_node_to_cpumask_map(void)
+{
+	unsigned int node;
+
+	/* setup nr_node_ids if not done yet */
+	if (nr_node_ids == MAX_NUMNODES)
+		setup_nr_node_ids();
+
+	/* allocate the map */
+	for_each_node(node)
+		alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
+
+	/* cpumask_of_node() will now work */
+	pr_debug("Node to cpumask map for %u nodes\n", nr_node_ids);
+}
+
+static int __init fake_numa_create_new_node(unsigned long end_pfn,
+						unsigned int *nid)
+{
+	unsigned long long mem;
+	char *p = cmdline;
+	static unsigned int fake_nid;
+	static unsigned long long curr_boundary;
+
+	/*
+	 * Modify node id, iff we started creating NUMA nodes
+	 * We want to continue from where we left of the last time
+	 */
+	if (fake_nid)
+		*nid = fake_nid;
+	/*
+	 * In case there are no more arguments to parse, the
+	 * node_id should be the same as the last fake node id
+	 * (we've handled this above).
+	 */
+	if (!p)
+		return 0;
+
+	mem = memparse(p, &p);
+	if (!mem)
+		return 0;
+
+	if (mem < curr_boundary)
+		return 0;
+
+	curr_boundary = mem;
+
+	if ((end_pfn << PAGE_SHIFT) > mem) {
+		/*
+		 * Skip commas and spaces
+		 */
+		while (*p == ',' || *p == ' ' || *p == '\t')
+			p++;
+
+		cmdline = p;
+		fake_nid++;
+		*nid = fake_nid;
+		pr_debug("created new fake_node with id %d\n", fake_nid);
+		return 1;
+	}
+	return 0;
+}
+
+static void __init reset_numa_cpu_lookup_table(void)
+{
+	unsigned int cpu;
+
+	for_each_possible_cpu(cpu)
+		numa_cpu_lookup_table[cpu] = -1;
+}
+
+void map_cpu_to_node(int cpu, int node)
+{
+	update_numa_cpu_lookup_table(cpu, node);
+
+	if (!(cpumask_test_cpu(cpu, node_to_cpumask_map[node]))) {
+		pr_debug("adding cpu %d to node %d\n", cpu, node);
+		cpumask_set_cpu(cpu, node_to_cpumask_map[node]);
+	}
+}
+
+#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PPC_SPLPAR)
+void unmap_cpu_from_node(unsigned long cpu)
+{
+	int node = numa_cpu_lookup_table[cpu];
+
+	if (cpumask_test_cpu(cpu, node_to_cpumask_map[node])) {
+		cpumask_clear_cpu(cpu, node_to_cpumask_map[node]);
+		pr_debug("removing cpu %lu from node %d\n", cpu, node);
+	} else {
+		pr_warn("Warning: cpu %lu not found in node %d\n", cpu, node);
+	}
+}
+#endif /* CONFIG_HOTPLUG_CPU || CONFIG_PPC_SPLPAR */
+
+static int __associativity_to_nid(const __be32 *associativity,
+				  int max_array_sz)
+{
+	int nid;
+	/*
+	 * primary_domain_index is 1 based array index.
+	 */
+	int index = primary_domain_index  - 1;
+
+	if (!numa_enabled || index >= max_array_sz)
+		return NUMA_NO_NODE;
+
+	nid = of_read_number(&associativity[index], 1);
+
+	/* POWER4 LPAR uses 0xffff as invalid node */
+	if (nid == 0xffff || nid >= nr_node_ids)
+		nid = NUMA_NO_NODE;
+	return nid;
+}
+/*
+ * Returns nid in the range [0..nr_node_ids], or -1 if no useful NUMA
+ * info is found.
+ */
+static int associativity_to_nid(const __be32 *associativity)
+{
+	int array_sz = of_read_number(associativity, 1);
+
+	/* Skip the first element in the associativity array */
+	return __associativity_to_nid((associativity + 1), array_sz);
+}
+
+static int __cpu_form2_relative_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
+{
+	int dist;
+	int node1, node2;
+
+	node1 = associativity_to_nid(cpu1_assoc);
+	node2 = associativity_to_nid(cpu2_assoc);
+
+	dist = numa_distance_table[node1][node2];
+	if (dist <= LOCAL_DISTANCE)
+		return 0;
+	else if (dist <= REMOTE_DISTANCE)
+		return 1;
+	else
+		return 2;
+}
+
+static int __cpu_form1_relative_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
+{
+	int dist = 0;
+
+	int i, index;
+
+	for (i = 0; i < distance_ref_points_depth; i++) {
+		index = be32_to_cpu(distance_ref_points[i]);
+		if (cpu1_assoc[index] == cpu2_assoc[index])
+			break;
+		dist++;
+	}
+
+	return dist;
+}
+
+int cpu_relative_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
+{
+	/* We should not get called with FORM0 */
+	VM_WARN_ON(affinity_form == FORM0_AFFINITY);
+	if (affinity_form == FORM1_AFFINITY)
+		return __cpu_form1_relative_distance(cpu1_assoc, cpu2_assoc);
+	return __cpu_form2_relative_distance(cpu1_assoc, cpu2_assoc);
+}
+
+/* must hold reference to node during call */
+static const __be32 *of_get_associativity(struct device_node *dev)
+{
+	return of_get_property(dev, "ibm,associativity", NULL);
+}
+
+int __node_distance(int a, int b)
+{
+	int i;
+	int distance = LOCAL_DISTANCE;
+
+	if (affinity_form == FORM2_AFFINITY)
+		return numa_distance_table[a][b];
+	else if (affinity_form == FORM0_AFFINITY)
+		return ((a == b) ? LOCAL_DISTANCE : REMOTE_DISTANCE);
+
+	for (i = 0; i < distance_ref_points_depth; i++) {
+		if (distance_lookup_table[a][i] == distance_lookup_table[b][i])
+			break;
+
+		/* Double the distance for each NUMA level */
+		distance *= 2;
+	}
+
+	return distance;
+}
+EXPORT_SYMBOL(__node_distance);
+
+/* Returns the nid associated with the given device tree node,
+ * or -1 if not found.
+ */
+static int of_node_to_nid_single(struct device_node *device)
+{
+	int nid = NUMA_NO_NODE;
+	const __be32 *tmp;
+
+	tmp = of_get_associativity(device);
+	if (tmp)
+		nid = associativity_to_nid(tmp);
+	return nid;
+}
+
+/* Walk the device tree upwards, looking for an associativity id */
+int of_node_to_nid(struct device_node *device)
+{
+	int nid = NUMA_NO_NODE;
+
+	of_node_get(device);
+	while (device) {
+		nid = of_node_to_nid_single(device);
+		if (nid != -1)
+			break;
+
+		device = of_get_next_parent(device);
+	}
+	of_node_put(device);
+
+	return nid;
+}
+EXPORT_SYMBOL(of_node_to_nid);
+
+static void __initialize_form1_numa_distance(const __be32 *associativity,
+					     int max_array_sz)
+{
+	int i, nid;
+
+	if (affinity_form != FORM1_AFFINITY)
+		return;
+
+	nid = __associativity_to_nid(associativity, max_array_sz);
+	if (nid != NUMA_NO_NODE) {
+		for (i = 0; i < distance_ref_points_depth; i++) {
+			const __be32 *entry;
+			int index = be32_to_cpu(distance_ref_points[i]) - 1;
+
+			/*
+			 * broken hierarchy, return with broken distance table
+			 */
+			if (WARN(index >= max_array_sz, "Broken ibm,associativity property"))
+				return;
+
+			entry = &associativity[index];
+			distance_lookup_table[nid][i] = of_read_number(entry, 1);
+		}
+	}
+}
+
+static void initialize_form1_numa_distance(const __be32 *associativity)
+{
+	int array_sz;
+
+	array_sz = of_read_number(associativity, 1);
+	/* Skip the first element in the associativity array */
+	__initialize_form1_numa_distance(associativity + 1, array_sz);
+}
+
+/*
+ * Used to update distance information w.r.t newly added node.
+ */
+void update_numa_distance(struct device_node *node)
+{
+	int nid;
+
+	if (affinity_form == FORM0_AFFINITY)
+		return;
+	else if (affinity_form == FORM1_AFFINITY) {
+		const __be32 *associativity;
+
+		associativity = of_get_associativity(node);
+		if (!associativity)
+			return;
+
+		initialize_form1_numa_distance(associativity);
+		return;
+	}
+
+	/* FORM2 affinity  */
+	nid = of_node_to_nid_single(node);
+	if (nid == NUMA_NO_NODE)
+		return;
+
+	/*
+	 * With FORM2 we expect NUMA distance of all possible NUMA
+	 * nodes to be provided during boot.
+	 */
+	WARN(numa_distance_table[nid][nid] == -1,
+	     "NUMA distance details for node %d not provided\n", nid);
+}
+EXPORT_SYMBOL_GPL(update_numa_distance);
+
+/*
+ * ibm,numa-lookup-index-table= {N, domainid1, domainid2, ..... domainidN}
+ * ibm,numa-distance-table = { N, 1, 2, 4, 5, 1, 6, .... N elements}
+ */
+static void __init initialize_form2_numa_distance_lookup_table(void)
+{
+	int i, j;
+	struct device_node *root;
+	const __u8 *form2_distances;
+	const __be32 *numa_lookup_index;
+	int form2_distances_length;
+	int max_numa_index, distance_index;
+
+	if (firmware_has_feature(FW_FEATURE_OPAL))
+		root = of_find_node_by_path("/ibm,opal");
+	else
+		root = of_find_node_by_path("/rtas");
+	if (!root)
+		root = of_find_node_by_path("/");
+
+	numa_lookup_index = of_get_property(root, "ibm,numa-lookup-index-table", NULL);
+	max_numa_index = of_read_number(&numa_lookup_index[0], 1);
+
+	/* first element of the array is the size and is encode-int */
+	form2_distances = of_get_property(root, "ibm,numa-distance-table", NULL);
+	form2_distances_length = of_read_number((const __be32 *)&form2_distances[0], 1);
+	/* Skip the size which is encoded int */
+	form2_distances += sizeof(__be32);
+
+	pr_debug("form2_distances_len = %d, numa_dist_indexes_len = %d\n",
+		 form2_distances_length, max_numa_index);
+
+	for (i = 0; i < max_numa_index; i++)
+		/* +1 skip the max_numa_index in the property */
+		numa_id_index_table[i] = of_read_number(&numa_lookup_index[i + 1], 1);
+
+
+	if (form2_distances_length != max_numa_index * max_numa_index) {
+		WARN(1, "Wrong NUMA distance information\n");
+		form2_distances = NULL; // don't use it
+	}
+	distance_index = 0;
+	for (i = 0;  i < max_numa_index; i++) {
+		for (j = 0; j < max_numa_index; j++) {
+			int nodeA = numa_id_index_table[i];
+			int nodeB = numa_id_index_table[j];
+			int dist;
+
+			if (form2_distances)
+				dist = form2_distances[distance_index++];
+			else if (nodeA == nodeB)
+				dist = LOCAL_DISTANCE;
+			else
+				dist = REMOTE_DISTANCE;
+			numa_distance_table[nodeA][nodeB] = dist;
+			pr_debug("dist[%d][%d]=%d ", nodeA, nodeB, dist);
+		}
+	}
+
+	of_node_put(root);
+}
+
+static int __init find_primary_domain_index(void)
+{
+	int index;
+	struct device_node *root;
+
+	/*
+	 * Check for which form of affinity.
+	 */
+	if (firmware_has_feature(FW_FEATURE_OPAL)) {
+		affinity_form = FORM1_AFFINITY;
+	} else if (firmware_has_feature(FW_FEATURE_FORM2_AFFINITY)) {
+		pr_debug("Using form 2 affinity\n");
+		affinity_form = FORM2_AFFINITY;
+	} else if (firmware_has_feature(FW_FEATURE_FORM1_AFFINITY)) {
+		pr_debug("Using form 1 affinity\n");
+		affinity_form = FORM1_AFFINITY;
+	} else
+		affinity_form = FORM0_AFFINITY;
+
+	if (firmware_has_feature(FW_FEATURE_OPAL))
+		root = of_find_node_by_path("/ibm,opal");
+	else
+		root = of_find_node_by_path("/rtas");
+	if (!root)
+		root = of_find_node_by_path("/");
+
+	/*
+	 * This property is a set of 32-bit integers, each representing
+	 * an index into the ibm,associativity nodes.
+	 *
+	 * With form 0 affinity the first integer is for an SMP configuration
+	 * (should be all 0's) and the second is for a normal NUMA
+	 * configuration. We have only one level of NUMA.
+	 *
+	 * With form 1 affinity the first integer is the most significant
+	 * NUMA boundary and the following are progressively less significant
+	 * boundaries. There can be more than one level of NUMA.
+	 */
+	distance_ref_points = of_get_property(root,
+					"ibm,associativity-reference-points",
+					&distance_ref_points_depth);
+
+	if (!distance_ref_points) {
+		pr_debug("ibm,associativity-reference-points not found.\n");
+		goto err;
+	}
+
+	distance_ref_points_depth /= sizeof(int);
+	if (affinity_form == FORM0_AFFINITY) {
+		if (distance_ref_points_depth < 2) {
+			pr_warn("short ibm,associativity-reference-points\n");
+			goto err;
+		}
+
+		index = of_read_number(&distance_ref_points[1], 1);
+	} else {
+		/*
+		 * Both FORM1 and FORM2 affinity find the primary domain details
+		 * at the same offset.
+		 */
+		index = of_read_number(distance_ref_points, 1);
+	}
+	/*
+	 * Warn and cap if the hardware supports more than
+	 * MAX_DISTANCE_REF_POINTS domains.
+	 */
+	if (distance_ref_points_depth > MAX_DISTANCE_REF_POINTS) {
+		pr_warn("distance array capped at %d entries\n",
+			MAX_DISTANCE_REF_POINTS);
+		distance_ref_points_depth = MAX_DISTANCE_REF_POINTS;
+	}
+
+	of_node_put(root);
+	return index;
+
+err:
+	of_node_put(root);
+	return -1;
+}
+
+static void __init get_n_mem_cells(int *n_addr_cells, int *n_size_cells)
+{
+	struct device_node *memory = NULL;
+
+	memory = of_find_node_by_type(memory, "memory");
+	if (!memory)
+		panic("numa.c: No memory nodes found!");
+
+	*n_addr_cells = of_n_addr_cells(memory);
+	*n_size_cells = of_n_size_cells(memory);
+	of_node_put(memory);
+}
+
+static unsigned long read_n_cells(int n, const __be32 **buf)
+{
+	unsigned long result = 0;
+
+	while (n--) {
+		result = (result << 32) | of_read_number(*buf, 1);
+		(*buf)++;
+	}
+	return result;
+}
+
+struct assoc_arrays {
+	u32	n_arrays;
+	u32	array_sz;
+	const __be32 *arrays;
+};
+
+/*
+ * Retrieve and validate the list of associativity arrays for drconf
+ * memory from the ibm,associativity-lookup-arrays property of the
+ * device tree..
+ *
+ * The layout of the ibm,associativity-lookup-arrays property is a number N
+ * indicating the number of associativity arrays, followed by a number M
+ * indicating the size of each associativity array, followed by a list
+ * of N associativity arrays.
+ */
+static int of_get_assoc_arrays(struct assoc_arrays *aa)
+{
+	struct device_node *memory;
+	const __be32 *prop;
+	u32 len;
+
+	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+	if (!memory)
+		return -1;
+
+	prop = of_get_property(memory, "ibm,associativity-lookup-arrays", &len);
+	if (!prop || len < 2 * sizeof(unsigned int)) {
+		of_node_put(memory);
+		return -1;
+	}
+
+	aa->n_arrays = of_read_number(prop++, 1);
+	aa->array_sz = of_read_number(prop++, 1);
+
+	of_node_put(memory);
+
+	/* Now that we know the number of arrays and size of each array,
+	 * revalidate the size of the property read in.
+	 */
+	if (len < (aa->n_arrays * aa->array_sz + 2) * sizeof(unsigned int))
+		return -1;
+
+	aa->arrays = prop;
+	return 0;
+}
+
+static int __init get_nid_and_numa_distance(struct drmem_lmb *lmb)
+{
+	struct assoc_arrays aa = { .arrays = NULL };
+	int default_nid = NUMA_NO_NODE;
+	int nid = default_nid;
+	int rc, index;
+
+	if ((primary_domain_index < 0) || !numa_enabled)
+		return default_nid;
+
+	rc = of_get_assoc_arrays(&aa);
+	if (rc)
+		return default_nid;
+
+	if (primary_domain_index <= aa.array_sz &&
+	    !(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index < aa.n_arrays) {
+		const __be32 *associativity;
+
+		index = lmb->aa_index * aa.array_sz;
+		associativity = &aa.arrays[index];
+		nid = __associativity_to_nid(associativity, aa.array_sz);
+		if (nid > 0 && affinity_form == FORM1_AFFINITY) {
+			/*
+			 * lookup array associativity entries have
+			 * no length of the array as the first element.
+			 */
+			__initialize_form1_numa_distance(associativity, aa.array_sz);
+		}
+	}
+	return nid;
+}
+
+/*
+ * This is like of_node_to_nid_single() for memory represented in the
+ * ibm,dynamic-reconfiguration-memory node.
+ */
+int of_drconf_to_nid_single(struct drmem_lmb *lmb)
+{
+	struct assoc_arrays aa = { .arrays = NULL };
+	int default_nid = NUMA_NO_NODE;
+	int nid = default_nid;
+	int rc, index;
+
+	if ((primary_domain_index < 0) || !numa_enabled)
+		return default_nid;
+
+	rc = of_get_assoc_arrays(&aa);
+	if (rc)
+		return default_nid;
+
+	if (primary_domain_index <= aa.array_sz &&
+	    !(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index < aa.n_arrays) {
+		const __be32 *associativity;
+
+		index = lmb->aa_index * aa.array_sz;
+		associativity = &aa.arrays[index];
+		nid = __associativity_to_nid(associativity, aa.array_sz);
+	}
+	return nid;
+}
+
+#ifdef CONFIG_PPC_SPLPAR
+
+static int __vphn_get_associativity(long lcpu, __be32 *associativity)
+{
+	long rc, hwid;
+
+	/*
+	 * On a shared lpar, device tree will not have node associativity.
+	 * At this time lppaca, or its __old_status field may not be
+	 * updated. Hence kernel cannot detect if its on a shared lpar. So
+	 * request an explicit associativity irrespective of whether the
+	 * lpar is shared or dedicated. Use the device tree property as a
+	 * fallback. cpu_to_phys_id is only valid between
+	 * smp_setup_cpu_maps() and smp_setup_pacas().
+	 */
+	if (firmware_has_feature(FW_FEATURE_VPHN)) {
+		if (cpu_to_phys_id)
+			hwid = cpu_to_phys_id[lcpu];
+		else
+			hwid = get_hard_smp_processor_id(lcpu);
+
+		rc = hcall_vphn(hwid, VPHN_FLAG_VCPU, associativity);
+		if (rc == H_SUCCESS)
+			return 0;
+	}
+
+	return -1;
+}
+
+static int vphn_get_nid(long lcpu)
+{
+	__be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
+
+
+	if (!__vphn_get_associativity(lcpu, associativity))
+		return associativity_to_nid(associativity);
+
+	return NUMA_NO_NODE;
+
+}
+#else
+
+static int __vphn_get_associativity(long lcpu, __be32 *associativity)
+{
+	return -1;
+}
+
+static int vphn_get_nid(long unused)
+{
+	return NUMA_NO_NODE;
+}
+#endif  /* CONFIG_PPC_SPLPAR */
+
+/*
+ * Figure out to which domain a cpu belongs and stick it there.
+ * Return the id of the domain used.
+ */
+static int numa_setup_cpu(unsigned long lcpu)
+{
+	struct device_node *cpu;
+	int fcpu = cpu_first_thread_sibling(lcpu);
+	int nid = NUMA_NO_NODE;
+
+	if (!cpu_present(lcpu)) {
+		set_cpu_numa_node(lcpu, first_online_node);
+		return first_online_node;
+	}
+
+	/*
+	 * If a valid cpu-to-node mapping is already available, use it
+	 * directly instead of querying the firmware, since it represents
+	 * the most recent mapping notified to us by the platform (eg: VPHN).
+	 * Since cpu_to_node binding remains the same for all threads in the
+	 * core. If a valid cpu-to-node mapping is already available, for
+	 * the first thread in the core, use it.
+	 */
+	nid = numa_cpu_lookup_table[fcpu];
+	if (nid >= 0) {
+		map_cpu_to_node(lcpu, nid);
+		return nid;
+	}
+
+	nid = vphn_get_nid(lcpu);
+	if (nid != NUMA_NO_NODE)
+		goto out_present;
+
+	cpu = of_get_cpu_node(lcpu, NULL);
+
+	if (!cpu) {
+		WARN_ON(1);
+		if (cpu_present(lcpu))
+			goto out_present;
+		else
+			goto out;
+	}
+
+	nid = of_node_to_nid_single(cpu);
+	of_node_put(cpu);
+
+out_present:
+	if (nid < 0 || !node_possible(nid))
+		nid = first_online_node;
+
+	/*
+	 * Update for the first thread of the core. All threads of a core
+	 * have to be part of the same node. This not only avoids querying
+	 * for every other thread in the core, but always avoids a case
+	 * where virtual node associativity change causes subsequent threads
+	 * of a core to be associated with different nid. However if first
+	 * thread is already online, expect it to have a valid mapping.
+	 */
+	if (fcpu != lcpu) {
+		WARN_ON(cpu_online(fcpu));
+		map_cpu_to_node(fcpu, nid);
+	}
+
+	map_cpu_to_node(lcpu, nid);
+out:
+	return nid;
+}
+
+static void verify_cpu_node_mapping(int cpu, int node)
+{
+	int base, sibling, i;
+
+	/* Verify that all the threads in the core belong to the same node */
+	base = cpu_first_thread_sibling(cpu);
+
+	for (i = 0; i < threads_per_core; i++) {
+		sibling = base + i;
+
+		if (sibling == cpu || cpu_is_offline(sibling))
+			continue;
+
+		if (cpu_to_node(sibling) != node) {
+			WARN(1, "CPU thread siblings %d and %d don't belong"
+				" to the same node!\n", cpu, sibling);
+			break;
+		}
+	}
+}
+
+/* Must run before sched domains notifier. */
+static int ppc_numa_cpu_prepare(unsigned int cpu)
+{
+	int nid;
+
+	nid = numa_setup_cpu(cpu);
+	verify_cpu_node_mapping(cpu, nid);
+	return 0;
+}
+
+static int ppc_numa_cpu_dead(unsigned int cpu)
+{
+	return 0;
+}
+
+/*
+ * Check and possibly modify a memory region to enforce the memory limit.
+ *
+ * Returns the size the region should have to enforce the memory limit.
+ * This will either be the original value of size, a truncated value,
+ * or zero. If the returned value of size is 0 the region should be
+ * discarded as it lies wholly above the memory limit.
+ */
+static unsigned long __init numa_enforce_memory_limit(unsigned long start,
+						      unsigned long size)
+{
+	/*
+	 * We use memblock_end_of_DRAM() in here instead of memory_limit because
+	 * we've already adjusted it for the limit and it takes care of
+	 * having memory holes below the limit.  Also, in the case of
+	 * iommu_is_off, memory_limit is not set but is implicitly enforced.
+	 */
+
+	if (start + size <= memblock_end_of_DRAM())
+		return size;
+
+	if (start >= memblock_end_of_DRAM())
+		return 0;
+
+	return memblock_end_of_DRAM() - start;
+}
+
+/*
+ * Reads the counter for a given entry in
+ * linux,drconf-usable-memory property
+ */
+static inline int __init read_usm_ranges(const __be32 **usm)
+{
+	/*
+	 * For each lmb in ibm,dynamic-memory a corresponding
+	 * entry in linux,drconf-usable-memory property contains
+	 * a counter followed by that many (base, size) duple.
+	 * read the counter from linux,drconf-usable-memory
+	 */
+	return read_n_cells(n_mem_size_cells, usm);
+}
+
+/*
+ * Extract NUMA information from the ibm,dynamic-reconfiguration-memory
+ * node.  This assumes n_mem_{addr,size}_cells have been set.
+ */
+static int __init numa_setup_drmem_lmb(struct drmem_lmb *lmb,
+					const __be32 **usm,
+					void *data)
+{
+	unsigned int ranges, is_kexec_kdump = 0;
+	unsigned long base, size, sz;
+	int nid;
+
+	/*
+	 * Skip this block if the reserved bit is set in flags (0x80)
+	 * or if the block is not assigned to this partition (0x8)
+	 */
+	if ((lmb->flags & DRCONF_MEM_RESERVED)
+	    || !(lmb->flags & DRCONF_MEM_ASSIGNED))
+		return 0;
+
+	if (*usm)
+		is_kexec_kdump = 1;
+
+	base = lmb->base_addr;
+	size = drmem_lmb_size();
+	ranges = 1;
+
+	if (is_kexec_kdump) {
+		ranges = read_usm_ranges(usm);
+		if (!ranges) /* there are no (base, size) duple */
+			return 0;
+	}
+
+	do {
+		if (is_kexec_kdump) {
+			base = read_n_cells(n_mem_addr_cells, usm);
+			size = read_n_cells(n_mem_size_cells, usm);
+		}
+
+		nid = get_nid_and_numa_distance(lmb);
+		fake_numa_create_new_node(((base + size) >> PAGE_SHIFT),
+					  &nid);
+		node_set_online(nid);
+		sz = numa_enforce_memory_limit(base, size);
+		if (sz)
+			memblock_set_node(base, sz, &memblock.memory, nid);
+	} while (--ranges);
+
+	return 0;
+}
+
+static int __init parse_numa_properties(void)
+{
+	struct device_node *memory;
+	int default_nid = 0;
+	unsigned long i;
+	const __be32 *associativity;
+
+	if (numa_enabled == 0) {
+		pr_warn("disabled by user\n");
+		return -1;
+	}
+
+	primary_domain_index = find_primary_domain_index();
+
+	if (primary_domain_index < 0) {
+		/*
+		 * if we fail to parse primary_domain_index from device tree
+		 * mark the numa disabled, boot with numa disabled.
+		 */
+		numa_enabled = false;
+		return primary_domain_index;
+	}
+
+	pr_debug("associativity depth for CPU/Memory: %d\n", primary_domain_index);
+
+	/*
+	 * If it is FORM2 initialize the distance table here.
+	 */
+	if (affinity_form == FORM2_AFFINITY)
+		initialize_form2_numa_distance_lookup_table();
+
+	/*
+	 * Even though we connect cpus to numa domains later in SMP
+	 * init, we need to know the node ids now. This is because
+	 * each node to be onlined must have NODE_DATA etc backing it.
+	 */
+	for_each_present_cpu(i) {
+		__be32 vphn_assoc[VPHN_ASSOC_BUFSIZE];
+		struct device_node *cpu;
+		int nid = NUMA_NO_NODE;
+
+		memset(vphn_assoc, 0, VPHN_ASSOC_BUFSIZE * sizeof(__be32));
+
+		if (__vphn_get_associativity(i, vphn_assoc) == 0) {
+			nid = associativity_to_nid(vphn_assoc);
+			initialize_form1_numa_distance(vphn_assoc);
+		} else {
+
+			/*
+			 * Don't fall back to default_nid yet -- we will plug
+			 * cpus into nodes once the memory scan has discovered
+			 * the topology.
+			 */
+			cpu = of_get_cpu_node(i, NULL);
+			BUG_ON(!cpu);
+
+			associativity = of_get_associativity(cpu);
+			if (associativity) {
+				nid = associativity_to_nid(associativity);
+				initialize_form1_numa_distance(associativity);
+			}
+			of_node_put(cpu);
+		}
+
+		/* node_set_online() is an UB if 'nid' is negative */
+		if (likely(nid >= 0))
+			node_set_online(nid);
+	}
+
+	get_n_mem_cells(&n_mem_addr_cells, &n_mem_size_cells);
+
+	for_each_node_by_type(memory, "memory") {
+		unsigned long start;
+		unsigned long size;
+		int nid;
+		int ranges;
+		const __be32 *memcell_buf;
+		unsigned int len;
+
+		memcell_buf = of_get_property(memory,
+			"linux,usable-memory", &len);
+		if (!memcell_buf || len <= 0)
+			memcell_buf = of_get_property(memory, "reg", &len);
+		if (!memcell_buf || len <= 0)
+			continue;
+
+		/* ranges in cell */
+		ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
+new_range:
+		/* these are order-sensitive, and modify the buffer pointer */
+		start = read_n_cells(n_mem_addr_cells, &memcell_buf);
+		size = read_n_cells(n_mem_size_cells, &memcell_buf);
+
+		/*
+		 * Assumption: either all memory nodes or none will
+		 * have associativity properties.  If none, then
+		 * everything goes to default_nid.
+		 */
+		associativity = of_get_associativity(memory);
+		if (associativity) {
+			nid = associativity_to_nid(associativity);
+			initialize_form1_numa_distance(associativity);
+		} else
+			nid = default_nid;
+
+		fake_numa_create_new_node(((start + size) >> PAGE_SHIFT), &nid);
+		node_set_online(nid);
+
+		size = numa_enforce_memory_limit(start, size);
+		if (size)
+			memblock_set_node(start, size, &memblock.memory, nid);
+
+		if (--ranges)
+			goto new_range;
+	}
+
+	/*
+	 * Now do the same thing for each MEMBLOCK listed in the
+	 * ibm,dynamic-memory property in the
+	 * ibm,dynamic-reconfiguration-memory node.
+	 */
+	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+	if (memory) {
+		walk_drmem_lmbs(memory, NULL, numa_setup_drmem_lmb);
+		of_node_put(memory);
+	}
+
+	return 0;
+}
+
+static void __init setup_nonnuma(void)
+{
+	unsigned long top_of_ram = memblock_end_of_DRAM();
+	unsigned long total_ram = memblock_phys_mem_size();
+	unsigned long start_pfn, end_pfn;
+	unsigned int nid = 0;
+	int i;
+
+	pr_debug("Top of RAM: 0x%lx, Total RAM: 0x%lx\n", top_of_ram, total_ram);
+	pr_debug("Memory hole size: %ldMB\n", (top_of_ram - total_ram) >> 20);
+
+	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
+		fake_numa_create_new_node(end_pfn, &nid);
+		memblock_set_node(PFN_PHYS(start_pfn),
+				  PFN_PHYS(end_pfn - start_pfn),
+				  &memblock.memory, nid);
+		node_set_online(nid);
+	}
+}
+
+void __init dump_numa_cpu_topology(void)
+{
+	unsigned int node;
+	unsigned int cpu, count;
+
+	if (!numa_enabled)
+		return;
+
+	for_each_online_node(node) {
+		pr_info("Node %d CPUs:", node);
+
+		count = 0;
+		/*
+		 * If we used a CPU iterator here we would miss printing
+		 * the holes in the cpumap.
+		 */
+		for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
+			if (cpumask_test_cpu(cpu,
+					node_to_cpumask_map[node])) {
+				if (count == 0)
+					pr_cont(" %u", cpu);
+				++count;
+			} else {
+				if (count > 1)
+					pr_cont("-%u", cpu - 1);
+				count = 0;
+			}
+		}
+
+		if (count > 1)
+			pr_cont("-%u", nr_cpu_ids - 1);
+		pr_cont("\n");
+	}
+}
+
+/* Initialize NODE_DATA for a node on the local memory */
+static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
+{
+	u64 spanned_pages = end_pfn - start_pfn;
+	const size_t nd_size = roundup(sizeof(pg_data_t), SMP_CACHE_BYTES);
+	u64 nd_pa;
+	void *nd;
+	int tnid;
+
+	nd_pa = memblock_phys_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
+	if (!nd_pa)
+		panic("Cannot allocate %zu bytes for node %d data\n",
+		      nd_size, nid);
+
+	nd = __va(nd_pa);
+
+	/* report and initialize */
+	pr_info("  NODE_DATA [mem %#010Lx-%#010Lx]\n",
+		nd_pa, nd_pa + nd_size - 1);
+	tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
+	if (tnid != nid)
+		pr_info("    NODE_DATA(%d) on node %d\n", nid, tnid);
+
+	node_data[nid] = nd;
+	memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
+	NODE_DATA(nid)->node_id = nid;
+	NODE_DATA(nid)->node_start_pfn = start_pfn;
+	NODE_DATA(nid)->node_spanned_pages = spanned_pages;
+}
+
+static void __init find_possible_nodes(void)
+{
+	struct device_node *rtas;
+	const __be32 *domains = NULL;
+	int prop_length, max_nodes;
+	u32 i;
+
+	if (!numa_enabled)
+		return;
+
+	rtas = of_find_node_by_path("/rtas");
+	if (!rtas)
+		return;
+
+	/*
+	 * ibm,current-associativity-domains is a fairly recent property. If
+	 * it doesn't exist, then fallback on ibm,max-associativity-domains.
+	 * Current denotes what the platform can support compared to max
+	 * which denotes what the Hypervisor can support.
+	 *
+	 * If the LPAR is migratable, new nodes might be activated after a LPM,
+	 * so we should consider the max number in that case.
+	 */
+	if (!of_get_property(of_root, "ibm,migratable-partition", NULL))
+		domains = of_get_property(rtas,
+					  "ibm,current-associativity-domains",
+					  &prop_length);
+	if (!domains) {
+		domains = of_get_property(rtas, "ibm,max-associativity-domains",
+					&prop_length);
+		if (!domains)
+			goto out;
+	}
+
+	max_nodes = of_read_number(&domains[primary_domain_index], 1);
+	pr_info("Partition configured for %d NUMA nodes.\n", max_nodes);
+
+	for (i = 0; i < max_nodes; i++) {
+		if (!node_possible(i))
+			node_set(i, node_possible_map);
+	}
+
+	prop_length /= sizeof(int);
+	if (prop_length > primary_domain_index + 2)
+		coregroup_enabled = 1;
+
+out:
+	of_node_put(rtas);
+}
+
+void __init mem_topology_setup(void)
+{
+	int cpu;
+
+	max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
+	min_low_pfn = MEMORY_START >> PAGE_SHIFT;
+
+	/*
+	 * Linux/mm assumes node 0 to be online at boot. However this is not
+	 * true on PowerPC, where node 0 is similar to any other node, it
+	 * could be cpuless, memoryless node. So force node 0 to be offline
+	 * for now. This will prevent cpuless, memoryless node 0 showing up
+	 * unnecessarily as online. If a node has cpus or memory that need
+	 * to be online, then node will anyway be marked online.
+	 */
+	node_set_offline(0);
+
+	if (parse_numa_properties())
+		setup_nonnuma();
+
+	/*
+	 * Modify the set of possible NUMA nodes to reflect information
+	 * available about the set of online nodes, and the set of nodes
+	 * that we expect to make use of for this platform's affinity
+	 * calculations.
+	 */
+	nodes_and(node_possible_map, node_possible_map, node_online_map);
+
+	find_possible_nodes();
+
+	setup_node_to_cpumask_map();
+
+	reset_numa_cpu_lookup_table();
+
+	for_each_possible_cpu(cpu) {
+		/*
+		 * Powerpc with CONFIG_NUMA always used to have a node 0,
+		 * even if it was memoryless or cpuless. For all cpus that
+		 * are possible but not present, cpu_to_node() would point
+		 * to node 0. To remove a cpuless, memoryless dummy node,
+		 * powerpc need to make sure all possible but not present
+		 * cpu_to_node are set to a proper node.
+		 */
+		numa_setup_cpu(cpu);
+	}
+}
+
+void __init initmem_init(void)
+{
+	int nid;
+
+	memblock_dump_all();
+
+	for_each_online_node(nid) {
+		unsigned long start_pfn, end_pfn;
+
+		get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
+		setup_node_data(nid, start_pfn, end_pfn);
+	}
+
+	sparse_init();
+
+	/*
+	 * We need the numa_cpu_lookup_table to be accurate for all CPUs,
+	 * even before we online them, so that we can use cpu_to_{node,mem}
+	 * early in boot, cf. smp_prepare_cpus().
+	 * _nocalls() + manual invocation is used because cpuhp is not yet
+	 * initialized for the boot CPU.
+	 */
+	cpuhp_setup_state_nocalls(CPUHP_POWER_NUMA_PREPARE, "powerpc/numa:prepare",
+				  ppc_numa_cpu_prepare, ppc_numa_cpu_dead);
+}
+
+static int __init early_numa(char *p)
+{
+	if (!p)
+		return 0;
+
+	if (strstr(p, "off"))
+		numa_enabled = 0;
+
+	p = strstr(p, "fake=");
+	if (p)
+		cmdline = p + strlen("fake=");
+
+	return 0;
+}
+early_param("numa", early_numa);
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+/*
+ * Find the node associated with a hot added memory section for
+ * memory represented in the device tree by the property
+ * ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory.
+ */
+static int hot_add_drconf_scn_to_nid(unsigned long scn_addr)
+{
+	struct drmem_lmb *lmb;
+	unsigned long lmb_size;
+	int nid = NUMA_NO_NODE;
+
+	lmb_size = drmem_lmb_size();
+
+	for_each_drmem_lmb(lmb) {
+		/* skip this block if it is reserved or not assigned to
+		 * this partition */
+		if ((lmb->flags & DRCONF_MEM_RESERVED)
+		    || !(lmb->flags & DRCONF_MEM_ASSIGNED))
+			continue;
+
+		if ((scn_addr < lmb->base_addr)
+		    || (scn_addr >= (lmb->base_addr + lmb_size)))
+			continue;
+
+		nid = of_drconf_to_nid_single(lmb);
+		break;
+	}
+
+	return nid;
+}
+
+/*
+ * Find the node associated with a hot added memory section for memory
+ * represented in the device tree as a node (i.e. memory@XXXX) for
+ * each memblock.
+ */
+static int hot_add_node_scn_to_nid(unsigned long scn_addr)
+{
+	struct device_node *memory;
+	int nid = NUMA_NO_NODE;
+
+	for_each_node_by_type(memory, "memory") {
+		int i = 0;
+
+		while (1) {
+			struct resource res;
+
+			if (of_address_to_resource(memory, i++, &res))
+				break;
+
+			if ((scn_addr < res.start) || (scn_addr > res.end))
+				continue;
+
+			nid = of_node_to_nid_single(memory);
+			break;
+		}
+
+		if (nid >= 0)
+			break;
+	}
+
+	of_node_put(memory);
+
+	return nid;
+}
+
+/*
+ * Find the node associated with a hot added memory section.  Section
+ * corresponds to a SPARSEMEM section, not an MEMBLOCK.  It is assumed that
+ * sections are fully contained within a single MEMBLOCK.
+ */
+int hot_add_scn_to_nid(unsigned long scn_addr)
+{
+	struct device_node *memory = NULL;
+	int nid;
+
+	if (!numa_enabled)
+		return first_online_node;
+
+	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+	if (memory) {
+		nid = hot_add_drconf_scn_to_nid(scn_addr);
+		of_node_put(memory);
+	} else {
+		nid = hot_add_node_scn_to_nid(scn_addr);
+	}
+
+	if (nid < 0 || !node_possible(nid))
+		nid = first_online_node;
+
+	return nid;
+}
+
+static u64 hot_add_drconf_memory_max(void)
+{
+	struct device_node *memory = NULL;
+	struct device_node *dn = NULL;
+	const __be64 *lrdr = NULL;
+
+	dn = of_find_node_by_path("/rtas");
+	if (dn) {
+		lrdr = of_get_property(dn, "ibm,lrdr-capacity", NULL);
+		of_node_put(dn);
+		if (lrdr)
+			return be64_to_cpup(lrdr);
+	}
+
+	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+	if (memory) {
+		of_node_put(memory);
+		return drmem_lmb_memory_max();
+	}
+	return 0;
+}
+
+/*
+ * memory_hotplug_max - return max address of memory that may be added
+ *
+ * This is currently only used on systems that support drconfig memory
+ * hotplug.
+ */
+u64 memory_hotplug_max(void)
+{
+        return max(hot_add_drconf_memory_max(), memblock_end_of_DRAM());
+}
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+/* Virtual Processor Home Node (VPHN) support */
+#ifdef CONFIG_PPC_SPLPAR
+static int topology_inited;
+
+/*
+ * Retrieve the new associativity information for a virtual processor's
+ * home node.
+ */
+static long vphn_get_associativity(unsigned long cpu,
+					__be32 *associativity)
+{
+	long rc;
+
+	rc = hcall_vphn(get_hard_smp_processor_id(cpu),
+				VPHN_FLAG_VCPU, associativity);
+
+	switch (rc) {
+	case H_SUCCESS:
+		pr_debug("VPHN hcall succeeded. Reset polling...\n");
+		goto out;
+
+	case H_FUNCTION:
+		pr_err_ratelimited("VPHN unsupported. Disabling polling...\n");
+		break;
+	case H_HARDWARE:
+		pr_err_ratelimited("hcall_vphn() experienced a hardware fault "
+			"preventing VPHN. Disabling polling...\n");
+		break;
+	case H_PARAMETER:
+		pr_err_ratelimited("hcall_vphn() was passed an invalid parameter. "
+			"Disabling polling...\n");
+		break;
+	default:
+		pr_err_ratelimited("hcall_vphn() returned %ld. Disabling polling...\n"
+			, rc);
+		break;
+	}
+out:
+	return rc;
+}
+
+void find_and_update_cpu_nid(int cpu)
+{
+	__be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
+	int new_nid;
+
+	/* Use associativity from first thread for all siblings */
+	if (vphn_get_associativity(cpu, associativity))
+		return;
+
+	/* Do not have previous associativity, so find it now. */
+	new_nid = associativity_to_nid(associativity);
+
+	if (new_nid < 0 || !node_possible(new_nid))
+		new_nid = first_online_node;
+	else
+		// Associate node <-> cpu, so cpu_up() calls
+		// try_online_node() on the right node.
+		set_cpu_numa_node(cpu, new_nid);
+
+	pr_debug("%s:%d cpu %d nid %d\n", __func__, __LINE__, cpu, new_nid);
+}
+
+int cpu_to_coregroup_id(int cpu)
+{
+	__be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
+	int index;
+
+	if (cpu < 0 || cpu > nr_cpu_ids)
+		return -1;
+
+	if (!coregroup_enabled)
+		goto out;
+
+	if (!firmware_has_feature(FW_FEATURE_VPHN))
+		goto out;
+
+	if (vphn_get_associativity(cpu, associativity))
+		goto out;
+
+	index = of_read_number(associativity, 1);
+	if (index > primary_domain_index + 1)
+		return of_read_number(&associativity[index - 1], 1);
+
+out:
+	return cpu_to_core_id(cpu);
+}
+
+static int topology_update_init(void)
+{
+	topology_inited = 1;
+	return 0;
+}
+device_initcall(topology_update_init);
+#endif /* CONFIG_PPC_SPLPAR */