v4.19.13 snapshot.
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
new file mode 100644
index 0000000..5500e4e
--- /dev/null
+++ b/arch/powerpc/mm/numa.c
@@ -0,0 +1,1622 @@
+/*
+ * pSeries NUMA support
+ *
+ * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#define pr_fmt(fmt) "numa: " fmt
+
+#include <linux/threads.h>
+#include <linux/bootmem.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/memblock.h>
+#include <linux/of.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/prom.h>
+#include <asm/smp.h>
+#include <asm/cputhreads.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/drmem.h>
+
+static int numa_enabled = 1;
+
+static char *cmdline __initdata;
+
+static int numa_debug;
+#define dbg(args...) if (numa_debug) { printk(KERN_INFO args); }
+
+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 min_common_depth;
+static int n_mem_addr_cells, n_mem_size_cells;
+static int form1_affinity;
+
+#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];
+
+/*
+ * 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 */
+ dbg("Node to cpumask map for %d 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;
+ dbg("created new fake_node with id %d\n", fake_nid);
+ return 1;
+ }
+ return 0;
+}
+
+static void reset_numa_cpu_lookup_table(void)
+{
+ unsigned int cpu;
+
+ for_each_possible_cpu(cpu)
+ numa_cpu_lookup_table[cpu] = -1;
+}
+
+static void map_cpu_to_node(int cpu, int node)
+{
+ update_numa_cpu_lookup_table(cpu, node);
+
+ dbg("adding cpu %d to node %d\n", cpu, node);
+
+ if (!(cpumask_test_cpu(cpu, node_to_cpumask_map[node])))
+ cpumask_set_cpu(cpu, node_to_cpumask_map[node]);
+}
+
+#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PPC_SPLPAR)
+static void unmap_cpu_from_node(unsigned long cpu)
+{
+ int node = numa_cpu_lookup_table[cpu];
+
+ dbg("removing cpu %lu from node %d\n", cpu, node);
+
+ if (cpumask_test_cpu(cpu, node_to_cpumask_map[node])) {
+ cpumask_clear_cpu(cpu, node_to_cpumask_map[node]);
+ } else {
+ printk(KERN_ERR "WARNING: cpu %lu not found in node %d\n",
+ cpu, node);
+ }
+}
+#endif /* CONFIG_HOTPLUG_CPU || CONFIG_PPC_SPLPAR */
+
+/* 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 (!form1_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);
+
+static void initialize_distance_lookup_table(int nid,
+ const __be32 *associativity)
+{
+ int i;
+
+ if (!form1_affinity)
+ return;
+
+ for (i = 0; i < distance_ref_points_depth; i++) {
+ const __be32 *entry;
+
+ entry = &associativity[be32_to_cpu(distance_ref_points[i]) - 1];
+ distance_lookup_table[nid][i] = of_read_number(entry, 1);
+ }
+}
+
+/* Returns nid in the range [0..MAX_NUMNODES-1], or -1 if no useful numa
+ * info is found.
+ */
+static int associativity_to_nid(const __be32 *associativity)
+{
+ int nid = -1;
+
+ if (min_common_depth == -1)
+ goto out;
+
+ if (of_read_number(associativity, 1) >= min_common_depth)
+ nid = of_read_number(&associativity[min_common_depth], 1);
+
+ /* POWER4 LPAR uses 0xffff as invalid node */
+ if (nid == 0xffff || nid >= MAX_NUMNODES)
+ nid = -1;
+
+ if (nid > 0 &&
+ of_read_number(associativity, 1) >= distance_ref_points_depth) {
+ /*
+ * Skip the length field and send start of associativity array
+ */
+ initialize_distance_lookup_table(nid, associativity + 1);
+ }
+
+out:
+ return nid;
+}
+
+/* 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 = -1;
+ 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 = -1;
+
+ 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 int __init find_min_common_depth(void)
+{
+ int depth;
+ struct device_node *root;
+
+ 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) {
+ dbg("NUMA: ibm,associativity-reference-points not found.\n");
+ goto err;
+ }
+
+ distance_ref_points_depth /= sizeof(int);
+
+ if (firmware_has_feature(FW_FEATURE_OPAL) ||
+ firmware_has_feature(FW_FEATURE_TYPE1_AFFINITY)) {
+ dbg("Using form 1 affinity\n");
+ form1_affinity = 1;
+ }
+
+ if (form1_affinity) {
+ depth = of_read_number(distance_ref_points, 1);
+ } else {
+ if (distance_ref_points_depth < 2) {
+ printk(KERN_WARNING "NUMA: "
+ "short ibm,associativity-reference-points\n");
+ goto err;
+ }
+
+ depth = of_read_number(&distance_ref_points[1], 1);
+ }
+
+ /*
+ * Warn and cap if the hardware supports more than
+ * MAX_DISTANCE_REF_POINTS domains.
+ */
+ if (distance_ref_points_depth > MAX_DISTANCE_REF_POINTS) {
+ printk(KERN_WARNING "NUMA: distance array capped at "
+ "%d entries\n", MAX_DISTANCE_REF_POINTS);
+ distance_ref_points_depth = MAX_DISTANCE_REF_POINTS;
+ }
+
+ of_node_put(root);
+ return depth;
+
+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;
+}
+
+/*
+ * This is like of_node_to_nid_single() for memory represented in the
+ * ibm,dynamic-reconfiguration-memory node.
+ */
+static int of_drconf_to_nid_single(struct drmem_lmb *lmb)
+{
+ struct assoc_arrays aa = { .arrays = NULL };
+ int default_nid = 0;
+ int nid = default_nid;
+ int rc, index;
+
+ rc = of_get_assoc_arrays(&aa);
+ if (rc)
+ return default_nid;
+
+ if (min_common_depth > 0 && min_common_depth <= aa.array_sz &&
+ !(lmb->flags & DRCONF_MEM_AI_INVALID) &&
+ lmb->aa_index < aa.n_arrays) {
+ index = lmb->aa_index * aa.array_sz + min_common_depth - 1;
+ nid = of_read_number(&aa.arrays[index], 1);
+
+ if (nid == 0xffff || nid >= MAX_NUMNODES)
+ nid = default_nid;
+
+ if (nid > 0) {
+ index = lmb->aa_index * aa.array_sz;
+ initialize_distance_lookup_table(nid,
+ &aa.arrays[index]);
+ }
+ }
+
+ return nid;
+}
+
+/*
+ * 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)
+{
+ int nid = -1;
+ struct device_node *cpu;
+
+ /*
+ * 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).
+ */
+ if ((nid = numa_cpu_lookup_table[lcpu]) >= 0) {
+ map_cpu_to_node(lcpu, nid);
+ return nid;
+ }
+
+ 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);
+
+out_present:
+ if (nid < 0 || !node_possible(nid))
+ nid = first_online_node;
+
+ map_cpu_to_node(lcpu, nid);
+ of_node_put(cpu);
+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)
+{
+#ifdef CONFIG_HOTPLUG_CPU
+ unmap_cpu_from_node(cpu);
+#endif
+ 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 void __init numa_setup_drmem_lmb(struct drmem_lmb *lmb,
+ const __be32 **usm)
+{
+ 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;
+
+ 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;
+ }
+
+ do {
+ if (is_kexec_kdump) {
+ base = read_n_cells(n_mem_addr_cells, usm);
+ size = read_n_cells(n_mem_size_cells, usm);
+ }
+
+ nid = of_drconf_to_nid_single(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);
+}
+
+static int __init parse_numa_properties(void)
+{
+ struct device_node *memory;
+ int default_nid = 0;
+ unsigned long i;
+
+ if (numa_enabled == 0) {
+ printk(KERN_WARNING "NUMA disabled by user\n");
+ return -1;
+ }
+
+ min_common_depth = find_min_common_depth();
+
+ if (min_common_depth < 0)
+ return min_common_depth;
+
+ dbg("NUMA associativity depth for CPU/Memory: %d\n", min_common_depth);
+
+ /*
+ * 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) {
+ struct device_node *cpu;
+ int nid;
+
+ cpu = of_get_cpu_node(i, NULL);
+ BUG_ON(!cpu);
+ nid = of_node_to_nid_single(cpu);
+ of_node_put(cpu);
+
+ /*
+ * Don't fall back to default_nid yet -- we will plug
+ * cpus into nodes once the memory scan has discovered
+ * the topology.
+ */
+ if (nid < 0)
+ continue;
+ 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.
+ */
+ nid = of_node_to_nid_single(memory);
+ if (nid < 0)
+ 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, 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;
+ struct memblock_region *reg;
+
+ printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
+ top_of_ram, total_ram);
+ printk(KERN_DEBUG "Memory hole size: %ldMB\n",
+ (top_of_ram - total_ram) >> 20);
+
+ for_each_memblock(memory, reg) {
+ start_pfn = memblock_region_memory_base_pfn(reg);
+ end_pfn = memblock_region_memory_end_pfn(reg);
+
+ 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 (min_common_depth == -1 || !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_alloc_try_nid(nd_size, SMP_CACHE_BYTES, 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;
+ u32 numnodes, i;
+
+ if (min_common_depth <= 0)
+ return;
+
+ rtas = of_find_node_by_path("/rtas");
+ if (!rtas)
+ return;
+
+ if (of_property_read_u32_index(rtas,
+ "ibm,max-associativity-domains",
+ min_common_depth, &numnodes))
+ goto out;
+
+ for (i = 0; i < numnodes; i++) {
+ if (!node_possible(i))
+ node_set(i, node_possible_map);
+ }
+
+out:
+ of_node_put(rtas);
+}
+
+void __init mem_topology_setup(void)
+{
+ int cpu;
+
+ 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_present_cpu(cpu)
+ numa_setup_cpu(cpu);
+}
+
+void __init initmem_init(void)
+{
+ int nid;
+
+ max_low_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
+ max_pfn = max_low_pfn;
+
+ 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_memory_present_with_active_regions(nid);
+ }
+
+ 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;
+
+ if (strstr(p, "debug"))
+ numa_debug = 1;
+
+ p = strstr(p, "fake=");
+ if (p)
+ cmdline = p + strlen("fake=");
+
+ return 0;
+}
+early_param("numa", early_numa);
+
+static bool topology_updates_enabled = true;
+
+static int __init early_topology_updates(char *p)
+{
+ if (!p)
+ return 0;
+
+ if (!strcmp(p, "off")) {
+ pr_info("Disabling topology updates\n");
+ topology_updates_enabled = false;
+ }
+
+ return 0;
+}
+early_param("topology_updates", early_topology_updates);
+
+#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 = -1;
+
+ 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 = -1;
+
+ for_each_node_by_type(memory, "memory") {
+ unsigned long start, size;
+ int ranges;
+ const __be32 *memcell_buf;
+ unsigned int len;
+
+ 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);
+
+ while (ranges--) {
+ start = read_n_cells(n_mem_addr_cells, &memcell_buf);
+ size = read_n_cells(n_mem_size_cells, &memcell_buf);
+
+ if ((scn_addr < start) || (scn_addr >= (start + size)))
+ 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 || (min_common_depth < 0))
+ 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
+
+#include "vphn.h"
+
+struct topology_update_data {
+ struct topology_update_data *next;
+ unsigned int cpu;
+ int old_nid;
+ int new_nid;
+};
+
+#define TOPOLOGY_DEF_TIMER_SECS 60
+
+static u8 vphn_cpu_change_counts[NR_CPUS][MAX_DISTANCE_REF_POINTS];
+static cpumask_t cpu_associativity_changes_mask;
+static int vphn_enabled;
+static int prrn_enabled;
+static void reset_topology_timer(void);
+static int topology_timer_secs = 1;
+static int topology_inited;
+
+/*
+ * Change polling interval for associativity changes.
+ */
+int timed_topology_update(int nsecs)
+{
+ if (vphn_enabled) {
+ if (nsecs > 0)
+ topology_timer_secs = nsecs;
+ else
+ topology_timer_secs = TOPOLOGY_DEF_TIMER_SECS;
+
+ reset_topology_timer();
+ }
+
+ return 0;
+}
+
+/*
+ * Store the current values of the associativity change counters in the
+ * hypervisor.
+ */
+static void setup_cpu_associativity_change_counters(void)
+{
+ int cpu;
+
+ /* The VPHN feature supports a maximum of 8 reference points */
+ BUILD_BUG_ON(MAX_DISTANCE_REF_POINTS > 8);
+
+ for_each_possible_cpu(cpu) {
+ int i;
+ u8 *counts = vphn_cpu_change_counts[cpu];
+ volatile u8 *hypervisor_counts = lppaca_of(cpu).vphn_assoc_counts;
+
+ for (i = 0; i < distance_ref_points_depth; i++)
+ counts[i] = hypervisor_counts[i];
+ }
+}
+
+/*
+ * The hypervisor maintains a set of 8 associativity change counters in
+ * the VPA of each cpu that correspond to the associativity levels in the
+ * ibm,associativity-reference-points property. When an associativity
+ * level changes, the corresponding counter is incremented.
+ *
+ * Set a bit in cpu_associativity_changes_mask for each cpu whose home
+ * node associativity levels have changed.
+ *
+ * Returns the number of cpus with unhandled associativity changes.
+ */
+static int update_cpu_associativity_changes_mask(void)
+{
+ int cpu;
+ cpumask_t *changes = &cpu_associativity_changes_mask;
+
+ for_each_possible_cpu(cpu) {
+ int i, changed = 0;
+ u8 *counts = vphn_cpu_change_counts[cpu];
+ volatile u8 *hypervisor_counts = lppaca_of(cpu).vphn_assoc_counts;
+
+ for (i = 0; i < distance_ref_points_depth; i++) {
+ if (hypervisor_counts[i] != counts[i]) {
+ counts[i] = hypervisor_counts[i];
+ changed = 1;
+ }
+ }
+ if (changed) {
+ cpumask_or(changes, changes, cpu_sibling_mask(cpu));
+ cpu = cpu_last_thread_sibling(cpu);
+ }
+ }
+
+ return cpumask_weight(changes);
+}
+
+/*
+ * Retrieve the new associativity information for a virtual processor's
+ * home node.
+ */
+static long hcall_vphn(unsigned long cpu, __be32 *associativity)
+{
+ long rc;
+ long retbuf[PLPAR_HCALL9_BUFSIZE] = {0};
+ u64 flags = 1;
+ int hwcpu = get_hard_smp_processor_id(cpu);
+
+ rc = plpar_hcall9(H_HOME_NODE_ASSOCIATIVITY, retbuf, flags, hwcpu);
+ vphn_unpack_associativity(retbuf, associativity);
+
+ return rc;
+}
+
+static long vphn_get_associativity(unsigned long cpu,
+ __be32 *associativity)
+{
+ long rc;
+
+ rc = hcall_vphn(cpu, associativity);
+
+ switch (rc) {
+ case H_FUNCTION:
+ printk_once(KERN_INFO
+ "VPHN is not supported. Disabling polling...\n");
+ stop_topology_update();
+ break;
+ case H_HARDWARE:
+ printk(KERN_ERR
+ "hcall_vphn() experienced a hardware fault "
+ "preventing VPHN. Disabling polling...\n");
+ stop_topology_update();
+ break;
+ case H_SUCCESS:
+ dbg("VPHN hcall succeeded. Reset polling...\n");
+ timed_topology_update(0);
+ break;
+ }
+
+ return rc;
+}
+
+int find_and_online_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 cpu_to_node(cpu);
+
+ new_nid = associativity_to_nid(associativity);
+ if (new_nid < 0 || !node_possible(new_nid))
+ new_nid = first_online_node;
+
+ if (NODE_DATA(new_nid) == NULL) {
+#ifdef CONFIG_MEMORY_HOTPLUG
+ /*
+ * Need to ensure that NODE_DATA is initialized for a node from
+ * available memory (see memblock_alloc_try_nid). If unable to
+ * init the node, then default to nearest node that has memory
+ * installed. Skip onlining a node if the subsystems are not
+ * yet initialized.
+ */
+ if (!topology_inited || try_online_node(new_nid))
+ new_nid = first_online_node;
+#else
+ /*
+ * Default to using the nearest node that has memory installed.
+ * Otherwise, it would be necessary to patch the kernel MM code
+ * to deal with more memoryless-node error conditions.
+ */
+ new_nid = first_online_node;
+#endif
+ }
+
+ pr_debug("%s:%d cpu %d nid %d\n", __FUNCTION__, __LINE__,
+ cpu, new_nid);
+ return new_nid;
+}
+
+/*
+ * Update the CPU maps and sysfs entries for a single CPU when its NUMA
+ * characteristics change. This function doesn't perform any locking and is
+ * only safe to call from stop_machine().
+ */
+static int update_cpu_topology(void *data)
+{
+ struct topology_update_data *update;
+ unsigned long cpu;
+
+ if (!data)
+ return -EINVAL;
+
+ cpu = smp_processor_id();
+
+ for (update = data; update; update = update->next) {
+ int new_nid = update->new_nid;
+ if (cpu != update->cpu)
+ continue;
+
+ unmap_cpu_from_node(cpu);
+ map_cpu_to_node(cpu, new_nid);
+ set_cpu_numa_node(cpu, new_nid);
+ set_cpu_numa_mem(cpu, local_memory_node(new_nid));
+ vdso_getcpu_init();
+ }
+
+ return 0;
+}
+
+static int update_lookup_table(void *data)
+{
+ struct topology_update_data *update;
+
+ if (!data)
+ return -EINVAL;
+
+ /*
+ * Upon topology update, the numa-cpu lookup table needs to be updated
+ * for all threads in the core, including offline CPUs, to ensure that
+ * future hotplug operations respect the cpu-to-node associativity
+ * properly.
+ */
+ for (update = data; update; update = update->next) {
+ int nid, base, j;
+
+ nid = update->new_nid;
+ base = cpu_first_thread_sibling(update->cpu);
+
+ for (j = 0; j < threads_per_core; j++) {
+ update_numa_cpu_lookup_table(base + j, nid);
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Update the node maps and sysfs entries for each cpu whose home node
+ * has changed. Returns 1 when the topology has changed, and 0 otherwise.
+ *
+ * cpus_locked says whether we already hold cpu_hotplug_lock.
+ */
+int numa_update_cpu_topology(bool cpus_locked)
+{
+ unsigned int cpu, sibling, changed = 0;
+ struct topology_update_data *updates, *ud;
+ cpumask_t updated_cpus;
+ struct device *dev;
+ int weight, new_nid, i = 0;
+
+ if (!prrn_enabled && !vphn_enabled && topology_inited)
+ return 0;
+
+ weight = cpumask_weight(&cpu_associativity_changes_mask);
+ if (!weight)
+ return 0;
+
+ updates = kcalloc(weight, sizeof(*updates), GFP_KERNEL);
+ if (!updates)
+ return 0;
+
+ cpumask_clear(&updated_cpus);
+
+ for_each_cpu(cpu, &cpu_associativity_changes_mask) {
+ /*
+ * If siblings aren't flagged for changes, updates list
+ * will be too short. Skip on this update and set for next
+ * update.
+ */
+ if (!cpumask_subset(cpu_sibling_mask(cpu),
+ &cpu_associativity_changes_mask)) {
+ pr_info("Sibling bits not set for associativity "
+ "change, cpu%d\n", cpu);
+ cpumask_or(&cpu_associativity_changes_mask,
+ &cpu_associativity_changes_mask,
+ cpu_sibling_mask(cpu));
+ cpu = cpu_last_thread_sibling(cpu);
+ continue;
+ }
+
+ new_nid = find_and_online_cpu_nid(cpu);
+
+ if (new_nid == numa_cpu_lookup_table[cpu]) {
+ cpumask_andnot(&cpu_associativity_changes_mask,
+ &cpu_associativity_changes_mask,
+ cpu_sibling_mask(cpu));
+ dbg("Assoc chg gives same node %d for cpu%d\n",
+ new_nid, cpu);
+ cpu = cpu_last_thread_sibling(cpu);
+ continue;
+ }
+
+ for_each_cpu(sibling, cpu_sibling_mask(cpu)) {
+ ud = &updates[i++];
+ ud->next = &updates[i];
+ ud->cpu = sibling;
+ ud->new_nid = new_nid;
+ ud->old_nid = numa_cpu_lookup_table[sibling];
+ cpumask_set_cpu(sibling, &updated_cpus);
+ }
+ cpu = cpu_last_thread_sibling(cpu);
+ }
+
+ /*
+ * Prevent processing of 'updates' from overflowing array
+ * where last entry filled in a 'next' pointer.
+ */
+ if (i)
+ updates[i-1].next = NULL;
+
+ pr_debug("Topology update for the following CPUs:\n");
+ if (cpumask_weight(&updated_cpus)) {
+ for (ud = &updates[0]; ud; ud = ud->next) {
+ pr_debug("cpu %d moving from node %d "
+ "to %d\n", ud->cpu,
+ ud->old_nid, ud->new_nid);
+ }
+ }
+
+ /*
+ * In cases where we have nothing to update (because the updates list
+ * is too short or because the new topology is same as the old one),
+ * skip invoking update_cpu_topology() via stop-machine(). This is
+ * necessary (and not just a fast-path optimization) since stop-machine
+ * can end up electing a random CPU to run update_cpu_topology(), and
+ * thus trick us into setting up incorrect cpu-node mappings (since
+ * 'updates' is kzalloc()'ed).
+ *
+ * And for the similar reason, we will skip all the following updating.
+ */
+ if (!cpumask_weight(&updated_cpus))
+ goto out;
+
+ if (cpus_locked)
+ stop_machine_cpuslocked(update_cpu_topology, &updates[0],
+ &updated_cpus);
+ else
+ stop_machine(update_cpu_topology, &updates[0], &updated_cpus);
+
+ /*
+ * Update the numa-cpu lookup table with the new mappings, even for
+ * offline CPUs. It is best to perform this update from the stop-
+ * machine context.
+ */
+ if (cpus_locked)
+ stop_machine_cpuslocked(update_lookup_table, &updates[0],
+ cpumask_of(raw_smp_processor_id()));
+ else
+ stop_machine(update_lookup_table, &updates[0],
+ cpumask_of(raw_smp_processor_id()));
+
+ for (ud = &updates[0]; ud; ud = ud->next) {
+ unregister_cpu_under_node(ud->cpu, ud->old_nid);
+ register_cpu_under_node(ud->cpu, ud->new_nid);
+
+ dev = get_cpu_device(ud->cpu);
+ if (dev)
+ kobject_uevent(&dev->kobj, KOBJ_CHANGE);
+ cpumask_clear_cpu(ud->cpu, &cpu_associativity_changes_mask);
+ changed = 1;
+ }
+
+out:
+ kfree(updates);
+ return changed;
+}
+
+int arch_update_cpu_topology(void)
+{
+ return numa_update_cpu_topology(true);
+}
+
+static void topology_work_fn(struct work_struct *work)
+{
+ rebuild_sched_domains();
+}
+static DECLARE_WORK(topology_work, topology_work_fn);
+
+static void topology_schedule_update(void)
+{
+ schedule_work(&topology_work);
+}
+
+static void topology_timer_fn(struct timer_list *unused)
+{
+ if (prrn_enabled && cpumask_weight(&cpu_associativity_changes_mask))
+ topology_schedule_update();
+ else if (vphn_enabled) {
+ if (update_cpu_associativity_changes_mask() > 0)
+ topology_schedule_update();
+ reset_topology_timer();
+ }
+}
+static struct timer_list topology_timer;
+
+static void reset_topology_timer(void)
+{
+ if (vphn_enabled)
+ mod_timer(&topology_timer, jiffies + topology_timer_secs * HZ);
+}
+
+#ifdef CONFIG_SMP
+
+static void stage_topology_update(int core_id)
+{
+ cpumask_or(&cpu_associativity_changes_mask,
+ &cpu_associativity_changes_mask, cpu_sibling_mask(core_id));
+ reset_topology_timer();
+}
+
+static int dt_update_callback(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct of_reconfig_data *update = data;
+ int rc = NOTIFY_DONE;
+
+ switch (action) {
+ case OF_RECONFIG_UPDATE_PROPERTY:
+ if (!of_prop_cmp(update->dn->type, "cpu") &&
+ !of_prop_cmp(update->prop->name, "ibm,associativity")) {
+ u32 core_id;
+ of_property_read_u32(update->dn, "reg", &core_id);
+ stage_topology_update(core_id);
+ rc = NOTIFY_OK;
+ }
+ break;
+ }
+
+ return rc;
+}
+
+static struct notifier_block dt_update_nb = {
+ .notifier_call = dt_update_callback,
+};
+
+#endif
+
+/*
+ * Start polling for associativity changes.
+ */
+int start_topology_update(void)
+{
+ int rc = 0;
+
+ if (firmware_has_feature(FW_FEATURE_PRRN)) {
+ if (!prrn_enabled) {
+ prrn_enabled = 1;
+#ifdef CONFIG_SMP
+ rc = of_reconfig_notifier_register(&dt_update_nb);
+#endif
+ }
+ }
+ if (firmware_has_feature(FW_FEATURE_VPHN) &&
+ lppaca_shared_proc(get_lppaca())) {
+ if (!vphn_enabled) {
+ vphn_enabled = 1;
+ setup_cpu_associativity_change_counters();
+ timer_setup(&topology_timer, topology_timer_fn,
+ TIMER_DEFERRABLE);
+ reset_topology_timer();
+ }
+ }
+
+ return rc;
+}
+
+/*
+ * Disable polling for VPHN associativity changes.
+ */
+int stop_topology_update(void)
+{
+ int rc = 0;
+
+ if (prrn_enabled) {
+ prrn_enabled = 0;
+#ifdef CONFIG_SMP
+ rc = of_reconfig_notifier_unregister(&dt_update_nb);
+#endif
+ }
+ if (vphn_enabled) {
+ vphn_enabled = 0;
+ rc = del_timer_sync(&topology_timer);
+ }
+
+ return rc;
+}
+
+int prrn_is_enabled(void)
+{
+ return prrn_enabled;
+}
+
+void __init shared_proc_topology_init(void)
+{
+ if (lppaca_shared_proc(get_lppaca())) {
+ bitmap_fill(cpumask_bits(&cpu_associativity_changes_mask),
+ nr_cpumask_bits);
+ numa_update_cpu_topology(false);
+ }
+}
+
+static int topology_read(struct seq_file *file, void *v)
+{
+ if (vphn_enabled || prrn_enabled)
+ seq_puts(file, "on\n");
+ else
+ seq_puts(file, "off\n");
+
+ return 0;
+}
+
+static int topology_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, topology_read, NULL);
+}
+
+static ssize_t topology_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *off)
+{
+ char kbuf[4]; /* "on" or "off" plus null. */
+ int read_len;
+
+ read_len = count < 3 ? count : 3;
+ if (copy_from_user(kbuf, buf, read_len))
+ return -EINVAL;
+
+ kbuf[read_len] = '\0';
+
+ if (!strncmp(kbuf, "on", 2))
+ start_topology_update();
+ else if (!strncmp(kbuf, "off", 3))
+ stop_topology_update();
+ else
+ return -EINVAL;
+
+ return count;
+}
+
+static const struct file_operations topology_ops = {
+ .read = seq_read,
+ .write = topology_write,
+ .open = topology_open,
+ .release = single_release
+};
+
+static int topology_update_init(void)
+{
+ /* Do not poll for changes if disabled at boot */
+ if (topology_updates_enabled)
+ start_topology_update();
+
+ if (vphn_enabled)
+ topology_schedule_update();
+
+ if (!proc_create("powerpc/topology_updates", 0644, NULL, &topology_ops))
+ return -ENOMEM;
+
+ topology_inited = 1;
+ return 0;
+}
+device_initcall(topology_update_init);
+#endif /* CONFIG_PPC_SPLPAR */