numa.c

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/*
 * pSeries NUMA support
 *
 * Copyright (C) 2002 Anton Blanchard <[email protected]>, 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.
 */
#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 <asm/sparsemem.h>
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/firmware.h>
#include <asm/paca.h>
#include <asm/hvcall.h>
#include <asm/setup.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 unsigned int *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, num = 0;

    /* setup nr_node_ids if not done yet */
    if (nr_node_ids == MAX_NUMNODES) {
        for_each_node_mask(node, node_possible_map)
            num = node;
        nr_node_ids = num + 1;
    }

    /* allocate the map */
    for (node = 0; node < nr_node_ids; 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 __cpuinit 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;
}

/*
 * get_node_active_region - Return active region containing pfn
 * Active range returned is empty if none found.
 * @pfn: The page to return the region for
 * @node_ar: Returned set to the active region containing @pfn
 */
static void __init get_node_active_region(unsigned long pfn,
                      struct node_active_region *node_ar)
{
    unsigned long start_pfn, end_pfn;
    int i, nid;

    for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
        if (pfn >= start_pfn && pfn < end_pfn) {
            node_ar->nid = nid;
            node_ar->start_pfn = start_pfn;
            node_ar->end_pfn = end_pfn;
            break;
        }
    }
}

static void map_cpu_to_node(int cpu, int node)
{
    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 int *of_get_associativity(struct device_node *dev)
{
    return of_get_property(dev, "ibm,associativity", NULL);
}

/*
 * Returns the property linux,drconf-usable-memory if
 * it exists (the property exists only in kexec/kdump kernels,
 * added by kexec-tools)
 */
static const u32 *of_get_usable_memory(struct device_node *memory)
{
    const u32 *prop;
    u32 len;
    prop = of_get_property(memory, "linux,drconf-usable-memory", &len);
    if (!prop || len < sizeof(unsigned int))
        return 0;
    return prop;
}

int __node_distance(int a, int b)
{
    int i;
    int distance = LOCAL_DISTANCE;

    if (!form1_affinity)
        return 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;
}

static void initialize_distance_lookup_table(int nid,
        const unsigned int *associativity)
{
    int i;

    if (!form1_affinity)
        return;

    for (i = 0; i < distance_ref_points_depth; i++) {
        distance_lookup_table[nid][i] =
            associativity[distance_ref_points[i]];
    }
}

/* Returns nid in the range [0..MAX_NUMNODES-1], or -1 if no useful numa
 * info is found.
 */
static int associativity_to_nid(const unsigned int *associativity)
{
    int nid = -1;

    if (min_common_depth == -1)
        goto out;

    if (associativity[0] >= min_common_depth)
        nid = associativity[min_common_depth];

    /* POWER4 LPAR uses 0xffff as invalid node */
    if (nid == 0xffff || nid >= MAX_NUMNODES)
        nid = -1;

    if (nid > 0 && associativity[0] >= distance_ref_points_depth)
        initialize_distance_lookup_table(nid, associativity);

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 unsigned int *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)
{
    struct device_node *tmp;
    int nid = -1;

    of_node_get(device);
    while (device) {
        nid = of_node_to_nid_single(device);
        if (nid != -1)
            break;

            tmp = device;
        device = of_get_parent(tmp);
        of_node_put(tmp);
    }
    of_node_put(device);

    return nid;
}
EXPORT_SYMBOL_GPL(of_node_to_nid);

static int __init find_min_common_depth(void)
{
    int depth;
    struct device_node *chosen;
    struct device_node *root;
    const char *vec5;

    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);

#define VEC5_AFFINITY_BYTE  5
#define VEC5_AFFINITY       0x80

    if (firmware_has_feature(FW_FEATURE_OPAL))
        form1_affinity = 1;
    else {
        chosen = of_find_node_by_path("/chosen");
        if (chosen) {
            vec5 = of_get_property(chosen,
                           "ibm,architecture-vec-5", NULL);
            if (vec5 && (vec5[VEC5_AFFINITY_BYTE] &
                            VEC5_AFFINITY)) {
                dbg("Using form 1 affinity\n");
                form1_affinity = 1;
            }

            of_node_put(chosen);
        }
    }

    if (form1_affinity) {
        depth = distance_ref_points[0];
    } else {
        if (distance_ref_points_depth < 2) {
            printk(KERN_WARNING "NUMA: "
                "short ibm,associativity-reference-points\n");
            goto err;
        }

        depth = 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) {
        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 unsigned int **buf)
{
    unsigned long result = 0;

    while (n--) {
        result = (result << 32) | **buf;
        (*buf)++;
    }
    return result;
}

struct of_drconf_cell {
    u64 base_addr;
    u32 drc_index;
    u32 reserved;
    u32 aa_index;
    u32 flags;
};

#define DRCONF_MEM_ASSIGNED 0x00000008
#define DRCONF_MEM_AI_INVALID   0x00000040
#define DRCONF_MEM_RESERVED 0x00000080

/*
 * Read the next memblock list entry from the ibm,dynamic-memory property
 * and return the information in the provided of_drconf_cell structure.
 */
static void read_drconf_cell(struct of_drconf_cell *drmem, const u32 **cellp)
{
    const u32 *cp;

    drmem->base_addr = read_n_cells(n_mem_addr_cells, cellp);

    cp = *cellp;
    drmem->drc_index = cp[0];
    drmem->reserved = cp[1];
    drmem->aa_index = cp[2];
    drmem->flags = cp[3];

    *cellp = cp + 4;
}

/*
 * Retrieve and validate the ibm,dynamic-memory property of the device tree.
 *
 * The layout of the ibm,dynamic-memory property is a number N of memblock
 * list entries followed by N memblock list entries.  Each memblock list entry
 * contains information as laid out in the of_drconf_cell struct above.
 */
static int of_get_drconf_memory(struct device_node *memory, const u32 **dm)
{
    const u32 *prop;
    u32 len, entries;

    prop = of_get_property(memory, "ibm,dynamic-memory", &len);
    if (!prop || len < sizeof(unsigned int))
        return 0;

    entries = *prop++;

    /* Now that we know the number of entries, revalidate the size
     * of the property read in to ensure we have everything
     */
    if (len < (entries * (n_mem_addr_cells + 4) + 1) * sizeof(unsigned int))
        return 0;

    *dm = prop;
    return entries;
}

/*
 * Retrieve and validate the ibm,lmb-size property for drconf memory
 * from the device tree.
 */
static u64 of_get_lmb_size(struct device_node *memory)
{
    const u32 *prop;
    u32 len;

    prop = of_get_property(memory, "ibm,lmb-size", &len);
    if (!prop || len < sizeof(unsigned int))
        return 0;

    return read_n_cells(n_mem_size_cells, &prop);
}

struct assoc_arrays {
    u32 n_arrays;
    u32 array_sz;
    const u32 *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 device_node *memory,
                   struct assoc_arrays *aa)
{
    const u32 *prop;
    u32 len;

    prop = of_get_property(memory, "ibm,associativity-lookup-arrays", &len);
    if (!prop || len < 2 * sizeof(unsigned int))
        return -1;

    aa->n_arrays = *prop++;
    aa->array_sz = *prop++;

    /* 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 of_drconf_cell *drmem,
                   struct assoc_arrays *aa)
{
    int default_nid = 0;
    int nid = default_nid;
    int index;

    if (min_common_depth > 0 && min_common_depth <= aa->array_sz &&
        !(drmem->flags & DRCONF_MEM_AI_INVALID) &&
        drmem->aa_index < aa->n_arrays) {
        index = drmem->aa_index * aa->array_sz + min_common_depth - 1;
        nid = aa->arrays[index];

        if (nid == 0xffff || nid >= MAX_NUMNODES)
            nid = default_nid;
    }

    return nid;
}

/*
 * Figure out to which domain a cpu belongs and stick it there.
 * Return the id of the domain used.
 */
static int __cpuinit numa_setup_cpu(unsigned long lcpu)
{
    int nid = 0;
    struct device_node *cpu = of_get_cpu_node(lcpu, NULL);

    if (!cpu) {
        WARN_ON(1);
        goto out;
    }

    nid = of_node_to_nid_single(cpu);

    if (nid < 0 || !node_online(nid))
        nid = first_online_node;
out:
    map_cpu_to_node(lcpu, nid);

    of_node_put(cpu);

    return nid;
}

static int __cpuinit cpu_numa_callback(struct notifier_block *nfb,
                 unsigned long action,
                 void *hcpu)
{
    unsigned long lcpu = (unsigned long)hcpu;
    int ret = NOTIFY_DONE;

    switch (action) {
    case CPU_UP_PREPARE:
    case CPU_UP_PREPARE_FROZEN:
        numa_setup_cpu(lcpu);
        ret = NOTIFY_OK;
        break;
#ifdef CONFIG_HOTPLUG_CPU
    case CPU_DEAD:
    case CPU_DEAD_FROZEN:
    case CPU_UP_CANCELED:
    case CPU_UP_CANCELED_FROZEN:
        unmap_cpu_from_node(lcpu);
        break;
        ret = NOTIFY_OK;
#endif
    }
    return ret;
}

/*
 * 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 u32 **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 parse_drconf_memory(struct device_node *memory)
{
    const u32 *uninitialized_var(dm), *usm;
    unsigned int n, rc, ranges, is_kexec_kdump = 0;
    unsigned long lmb_size, base, size, sz;
    int nid;
    struct assoc_arrays aa = { .arrays = NULL };

    n = of_get_drconf_memory(memory, &dm);
    if (!n)
        return;

    lmb_size = of_get_lmb_size(memory);
    if (!lmb_size)
        return;

    rc = of_get_assoc_arrays(memory, &aa);
    if (rc)
        return;

    /* check if this is a kexec/kdump kernel */
    usm = of_get_usable_memory(memory);
    if (usm != NULL)
        is_kexec_kdump = 1;

    for (; n != 0; --n) {
        struct of_drconf_cell drmem;

        read_drconf_cell(&drmem, &dm);

        /* skip this block if the reserved bit is set in flags (0x80)
           or if the block is not assigned to this partition (0x8) */
        if ((drmem.flags & DRCONF_MEM_RESERVED)
            || !(drmem.flags & DRCONF_MEM_ASSIGNED))
            continue;

        base = drmem.base_addr;
        size = lmb_size;
        ranges = 1;

        if (is_kexec_kdump) {
            ranges = read_usm_ranges(&usm);
            if (!ranges) /* there are no (base, size) duple */
                continue;
        }
        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(&drmem, &aa);
            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, 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 unsigned int *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);

        if (!(size = numa_enforce_memory_limit(start, size))) {
            if (--ranges)
                goto new_range;
            else
                continue;
        }

        memblock_set_node(start, size, 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)
        parse_drconf_memory(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), 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) {
        printk(KERN_DEBUG "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)
                    printk(" %u", cpu);
                ++count;
            } else {
                if (count > 1)
                    printk("-%u", cpu - 1);
                count = 0;
            }
        }

        if (count > 1)
            printk("-%u", nr_cpu_ids - 1);
        printk("\n");
    }
}

static void __init dump_numa_memory_topology(void)
{
    unsigned int node;
    unsigned int count;

    if (min_common_depth == -1 || !numa_enabled)
        return;

    for_each_online_node(node) {
        unsigned long i;

        printk(KERN_DEBUG "Node %d Memory:", node);

        count = 0;

        for (i = 0; i < memblock_end_of_DRAM();
             i += (1 << SECTION_SIZE_BITS)) {
            if (early_pfn_to_nid(i >> PAGE_SHIFT) == node) {
                if (count == 0)
                    printk(" 0x%lx", i);
                ++count;
            } else {
                if (count > 0)
                    printk("-0x%lx", i);
                count = 0;
            }
        }

        if (count > 0)
            printk("-0x%lx", i);
        printk("\n");
    }
}

/*
 * Allocate some memory, satisfying the memblock or bootmem allocator where
 * required. nid is the preferred node and end is the physical address of
 * the highest address in the node.
 *
 * Returns the virtual address of the memory.
 */
static void __init *careful_zallocation(int nid, unsigned long size,
                       unsigned long align,
                       unsigned long end_pfn)
{
    void *ret;
    int new_nid;
    unsigned long ret_paddr;

    ret_paddr = __memblock_alloc_base(size, align, end_pfn << PAGE_SHIFT);

    /* retry over all memory */
    if (!ret_paddr)
        ret_paddr = __memblock_alloc_base(size, align, memblock_end_of_DRAM());

    if (!ret_paddr)
        panic("numa.c: cannot allocate %lu bytes for node %d",
              size, nid);

    ret = __va(ret_paddr);

    /*
     * We initialize the nodes in numeric order: 0, 1, 2...
     * and hand over control from the MEMBLOCK allocator to the
     * bootmem allocator.  If this function is called for
     * node 5, then we know that all nodes <5 are using the
     * bootmem allocator instead of the MEMBLOCK allocator.
     *
     * So, check the nid from which this allocation came
     * and double check to see if we need to use bootmem
     * instead of the MEMBLOCK.  We don't free the MEMBLOCK memory
     * since it would be useless.
     */
    new_nid = early_pfn_to_nid(ret_paddr >> PAGE_SHIFT);
    if (new_nid < nid) {
        ret = __alloc_bootmem_node(NODE_DATA(new_nid),
                size, align, 0);

        dbg("alloc_bootmem %p %lx\n", ret, size);
    }

    memset(ret, 0, size);
    return ret;
}

static struct notifier_block __cpuinitdata ppc64_numa_nb = {
    .notifier_call = cpu_numa_callback,
    .priority = 1 /* Must run before sched domains notifier. */
};

static void __init mark_reserved_regions_for_nid(int nid)
{
    struct pglist_data *node = NODE_DATA(nid);
    struct memblock_region *reg;

    for_each_memblock(reserved, reg) {
        unsigned long physbase = reg->base;
        unsigned long size = reg->size;
        unsigned long start_pfn = physbase >> PAGE_SHIFT;
        unsigned long end_pfn = PFN_UP(physbase + size);
        struct node_active_region node_ar;
        unsigned long node_end_pfn = node->node_start_pfn +
                         node->node_spanned_pages;

        /*
         * Check to make sure that this memblock.reserved area is
         * within the bounds of the node that we care about.
         * Checking the nid of the start and end points is not
         * sufficient because the reserved area could span the
         * entire node.
         */
        if (end_pfn <= node->node_start_pfn ||
            start_pfn >= node_end_pfn)
            continue;

        get_node_active_region(start_pfn, &node_ar);
        while (start_pfn < end_pfn &&
            node_ar.start_pfn < node_ar.end_pfn) {
            unsigned long reserve_size = size;
            /*
             * if reserved region extends past active region
             * then trim size to active region
             */
            if (end_pfn > node_ar.end_pfn)
                reserve_size = (node_ar.end_pfn << PAGE_SHIFT)
                    - physbase;
            /*
             * Only worry about *this* node, others may not
             * yet have valid NODE_DATA().
             */
            if (node_ar.nid == nid) {
                dbg("reserve_bootmem %lx %lx nid=%d\n",
                    physbase, reserve_size, node_ar.nid);
                reserve_bootmem_node(NODE_DATA(node_ar.nid),
                        physbase, reserve_size,
                        BOOTMEM_DEFAULT);
            }
            /*
             * if reserved region is contained in the active region
             * then done.
             */
            if (end_pfn <= node_ar.end_pfn)
                break;

            /*
             * reserved region extends past the active region
             *   get next active region that contains this
             *   reserved region
             */
            start_pfn = node_ar.end_pfn;
            physbase = start_pfn << PAGE_SHIFT;
            size = size - reserve_size;
            get_node_active_region(start_pfn, &node_ar);
        }
    }
}


void __init do_init_bootmem(void)
{
    int nid;

    min_low_pfn = 0;
    max_low_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
    max_pfn = max_low_pfn;

    if (parse_numa_properties())
        setup_nonnuma();
    else
        dump_numa_memory_topology();

    for_each_online_node(nid) {
        unsigned long start_pfn, end_pfn;
        void *bootmem_vaddr;
        unsigned long bootmap_pages;

        get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);

        /*
         * Allocate the node structure node local if possible
         *
         * Be careful moving this around, as it relies on all
         * previous nodes' bootmem to be initialized and have
         * all reserved areas marked.
         */
        NODE_DATA(nid) = careful_zallocation(nid,
                    sizeof(struct pglist_data),
                    SMP_CACHE_BYTES, end_pfn);

        dbg("node %d\n", nid);
        dbg("NODE_DATA() = %p\n", NODE_DATA(nid));

        NODE_DATA(nid)->bdata = &bootmem_node_data[nid];
        NODE_DATA(nid)->node_start_pfn = start_pfn;
        NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;

        if (NODE_DATA(nid)->node_spanned_pages == 0)
            continue;

        dbg("start_paddr = %lx\n", start_pfn << PAGE_SHIFT);
        dbg("end_paddr = %lx\n", end_pfn << PAGE_SHIFT);

        bootmap_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
        bootmem_vaddr = careful_zallocation(nid,
                    bootmap_pages << PAGE_SHIFT,
                    PAGE_SIZE, end_pfn);

        dbg("bootmap_vaddr = %p\n", bootmem_vaddr);

        init_bootmem_node(NODE_DATA(nid),
                  __pa(bootmem_vaddr) >> PAGE_SHIFT,
                  start_pfn, end_pfn);

        free_bootmem_with_active_regions(nid, end_pfn);
        /*
         * Be very careful about moving this around.  Future
         * calls to careful_zallocation() depend on this getting
         * done correctly.
         */
        mark_reserved_regions_for_nid(nid);
        sparse_memory_present_with_active_regions(nid);
    }

    init_bootmem_done = 1;

    /*
     * Now bootmem is initialised we can create the node to cpumask
     * lookup tables and setup the cpu callback to populate them.
     */
    setup_node_to_cpumask_map();

    register_cpu_notifier(&ppc64_numa_nb);
    cpu_numa_callback(&ppc64_numa_nb, CPU_UP_PREPARE,
              (void *)(unsigned long)boot_cpuid);
}

void __init paging_init(void)
{
    unsigned long max_zone_pfns[MAX_NR_ZONES];
    memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
    max_zone_pfns[ZONE_DMA] = memblock_end_of_DRAM() >> PAGE_SHIFT;
    free_area_init_nodes(max_zone_pfns);
}

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);

#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(struct device_node *memory,
                     unsigned long scn_addr)
{
    const u32 *dm;
    unsigned int drconf_cell_cnt, rc;
    unsigned long lmb_size;
    struct assoc_arrays aa;
    int nid = -1;

    drconf_cell_cnt = of_get_drconf_memory(memory, &dm);
    if (!drconf_cell_cnt)
        return -1;

    lmb_size = of_get_lmb_size(memory);
    if (!lmb_size)
        return -1;

    rc = of_get_assoc_arrays(memory, &aa);
    if (rc)
        return -1;

    for (; drconf_cell_cnt != 0; --drconf_cell_cnt) {
        struct of_drconf_cell drmem;

        read_drconf_cell(&drmem, &dm);

        /* skip this block if it is reserved or not assigned to
         * this partition */
        if ((drmem.flags & DRCONF_MEM_RESERVED)
            || !(drmem.flags & DRCONF_MEM_ASSIGNED))
            continue;

        if ((scn_addr < drmem.base_addr)
            || (scn_addr >= (drmem.base_addr + lmb_size)))
            continue;

        nid = of_drconf_to_nid_single(&drmem, &aa);
        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.
 */
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 unsigned int *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, found = 0;

    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(memory, scn_addr);
        of_node_put(memory);
    } else {
        nid = hot_add_node_scn_to_nid(scn_addr);
    }

    if (nid < 0 || !node_online(nid))
        nid = first_online_node;

    if (NODE_DATA(nid)->node_spanned_pages)
        return nid;

    for_each_online_node(nid) {
        if (NODE_DATA(nid)->node_spanned_pages) {
            found = 1;
            break;
        }
    }

    BUG_ON(!found);
    return nid;
}

static u64 hot_add_drconf_memory_max(void)
{
        struct device_node *memory = NULL;
        unsigned int drconf_cell_cnt = 0;
        u64 lmb_size = 0;
        const u32 *dm = 0;

        memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
        if (memory) {
                drconf_cell_cnt = of_get_drconf_memory(memory, &dm);
                lmb_size = of_get_lmb_size(memory);
                of_node_put(memory);
        }
        return lmb_size * drconf_cell_cnt;
}

/*
 * 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 u8 vphn_cpu_change_counts[NR_CPUS][MAX_DISTANCE_REF_POINTS];
static cpumask_t cpu_associativity_changes_mask;
static int vphn_enabled;
static void set_topology_timer(void);

/*
 * 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[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, nr_cpus = 0;
    cpumask_t *changes = &cpu_associativity_changes_mask;

    cpumask_clear(changes);

    for_each_possible_cpu(cpu) {
        int i, changed = 0;
        u8 *counts = vphn_cpu_change_counts[cpu];
        volatile u8 *hypervisor_counts = lppaca[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_set_cpu(cpu, changes);
            nr_cpus++;
        }
    }

    return nr_cpus;
}

/*
 * 6 64-bit registers unpacked into 12 32-bit associativity values. To form
 * the complete property we have to add the length in the first cell.
 */
#define VPHN_ASSOC_BUFSIZE (6*sizeof(u64)/sizeof(u32) + 1)

/*
 * Convert the associativity domain numbers returned from the hypervisor
 * to the sequence they would appear in the ibm,associativity property.
 */
static int vphn_unpack_associativity(const long *packed, unsigned int *unpacked)
{
    int i, nr_assoc_doms = 0;
    const u16 *field = (const u16*) packed;

#define VPHN_FIELD_UNUSED   (0xffff)
#define VPHN_FIELD_MSB      (0x8000)
#define VPHN_FIELD_MASK     (~VPHN_FIELD_MSB)

    for (i = 1; i < VPHN_ASSOC_BUFSIZE; i++) {
        if (*field == VPHN_FIELD_UNUSED) {
            /* All significant fields processed, and remaining
             * fields contain the reserved value of all 1's.
             * Just store them.
             */
            unpacked[i] = *((u32*)field);
            field += 2;
        } else if (*field & VPHN_FIELD_MSB) {
            /* Data is in the lower 15 bits of this field */
            unpacked[i] = *field & VPHN_FIELD_MASK;
            field++;
            nr_assoc_doms++;
        } else {
            /* Data is in the lower 15 bits of this field
             * concatenated with the next 16 bit field
             */
            unpacked[i] = *((u32*)field);
            field += 2;
            nr_assoc_doms++;
        }
    }

    /* The first cell contains the length of the property */
    unpacked[0] = nr_assoc_doms;

    return nr_assoc_doms;
}

/*
 * Retrieve the new associativity information for a virtual processor's
 * home node.
 */
static long hcall_vphn(unsigned long cpu, unsigned int *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,
                    unsigned int *associativity)
{
    long rc;

    rc = hcall_vphn(cpu, associativity);

    switch (rc) {
    case H_FUNCTION:
        printk(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();
    }

    return rc;
}

/*
 * 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.
 */
int arch_update_cpu_topology(void)
{
    int cpu, nid, old_nid, changed = 0;
    unsigned int associativity[VPHN_ASSOC_BUFSIZE] = {0};
    struct device *dev;

    for_each_cpu(cpu,&cpu_associativity_changes_mask) {
        vphn_get_associativity(cpu, associativity);
        nid = associativity_to_nid(associativity);

        if (nid < 0 || !node_online(nid))
            nid = first_online_node;

        old_nid = numa_cpu_lookup_table[cpu];

        /* Disable hotplug while we update the cpu
         * masks and sysfs.
         */
        get_online_cpus();
        unregister_cpu_under_node(cpu, old_nid);
        unmap_cpu_from_node(cpu);
        map_cpu_to_node(cpu, nid);
        register_cpu_under_node(cpu, nid);
        put_online_cpus();

        dev = get_cpu_device(cpu);
        if (dev)
            kobject_uevent(&dev->kobj, KOBJ_CHANGE);
        changed = 1;
    }

    return changed;
}

static void topology_work_fn(struct work_struct *work)
{
    rebuild_sched_domains();
}
static DECLARE_WORK(topology_work, topology_work_fn);

void topology_schedule_update(void)
{
    schedule_work(&topology_work);
}

static void topology_timer_fn(unsigned long ignored)
{
    if (!vphn_enabled)
        return;
    if (update_cpu_associativity_changes_mask() > 0)
        topology_schedule_update();
    set_topology_timer();
}
static struct timer_list topology_timer =
    TIMER_INITIALIZER(topology_timer_fn, 0, 0);

static void set_topology_timer(void)
{
    topology_timer.data = 0;
    topology_timer.expires = jiffies + 60 * HZ;
    add_timer(&topology_timer);
}

/*
 * Start polling for VPHN associativity changes.
 */
int start_topology_update(void)
{
    int rc = 0;

    /* Disabled until races with load balancing are fixed */
    if (0 && firmware_has_feature(FW_FEATURE_VPHN) &&
        get_lppaca()->shared_proc) {
        vphn_enabled = 1;
        setup_cpu_associativity_change_counters();
        init_timer_deferrable(&topology_timer);
        set_topology_timer();
        rc = 1;
    }

    return rc;
}
__initcall(start_topology_update);

/*
 * Disable polling for VPHN associativity changes.
 */
int stop_topology_update(void)
{
    vphn_enabled = 0;
    return del_timer_sync(&topology_timer);
}
#endif /* CONFIG_PPC_SPLPAR */