hugetlb: handle memory hot-plug events

[linux-2.6/linux-2.6-openrd.git] / drivers / base / node.c

/*
 * drivers/base/node.c - basic Node class support
 */

#include <linux/sysdev.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/memory.h>
#include <linux/node.h>
#include <linux/hugetlb.h>
#include <linux/cpumask.h>
#include <linux/topology.h>
#include <linux/nodemask.h>
#include <linux/cpu.h>
#include <linux/device.h>
#include <linux/swap.h>

static struct sysdev_class node_class = {
        .name = "node",
};


static ssize_t node_read_cpumap(struct sys_device *dev, int type, char *buf)
{
        struct node *node_dev = to_node(dev);
        const struct cpumask *mask = cpumask_of_node(node_dev->sysdev.id);
        int len;

        /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
        BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));

        len = type?
                cpulist_scnprintf(buf, PAGE_SIZE-2, mask) :
                cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
        buf[len++] = '\n';
        buf[len] = '\0';
        return len;
}

static inline ssize_t node_read_cpumask(struct sys_device *dev,
                                struct sysdev_attribute *attr, char *buf)
{
        return node_read_cpumap(dev, 0, buf);
}
static inline ssize_t node_read_cpulist(struct sys_device *dev,
                                struct sysdev_attribute *attr, char *buf)
{
        return node_read_cpumap(dev, 1, buf);
}

static SYSDEV_ATTR(cpumap,  S_IRUGO, node_read_cpumask, NULL);
static SYSDEV_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);

#define K(x) ((x) << (PAGE_SHIFT - 10))
static ssize_t node_read_meminfo(struct sys_device * dev,
                        struct sysdev_attribute *attr, char * buf)
{
        int n;
        int nid = dev->id;
        struct sysinfo i;

        si_meminfo_node(&i, nid);

        n = sprintf(buf, "\n"
                       "Node %d MemTotal:       %8lu kB\n"
                       "Node %d MemFree:        %8lu kB\n"
                       "Node %d MemUsed:        %8lu kB\n"
                       "Node %d Active:         %8lu kB\n"
                       "Node %d Inactive:       %8lu kB\n"
                       "Node %d Active(anon):   %8lu kB\n"
                       "Node %d Inactive(anon): %8lu kB\n"
                       "Node %d Active(file):   %8lu kB\n"
                       "Node %d Inactive(file): %8lu kB\n"
                       "Node %d Unevictable:    %8lu kB\n"
                       "Node %d Mlocked:        %8lu kB\n"
#ifdef CONFIG_HIGHMEM
                       "Node %d HighTotal:      %8lu kB\n"
                       "Node %d HighFree:       %8lu kB\n"
                       "Node %d LowTotal:       %8lu kB\n"
                       "Node %d LowFree:        %8lu kB\n"
#endif
                       "Node %d Dirty:          %8lu kB\n"
                       "Node %d Writeback:      %8lu kB\n"
                       "Node %d FilePages:      %8lu kB\n"
                       "Node %d Mapped:         %8lu kB\n"
                       "Node %d AnonPages:      %8lu kB\n"
                       "Node %d Shmem:          %8lu kB\n"
                       "Node %d KernelStack:    %8lu kB\n"
                       "Node %d PageTables:     %8lu kB\n"
                       "Node %d NFS_Unstable:   %8lu kB\n"
                       "Node %d Bounce:         %8lu kB\n"
                       "Node %d WritebackTmp:   %8lu kB\n"
                       "Node %d Slab:           %8lu kB\n"
                       "Node %d SReclaimable:   %8lu kB\n"
                       "Node %d SUnreclaim:     %8lu kB\n",
                       nid, K(i.totalram),
                       nid, K(i.freeram),
                       nid, K(i.totalram - i.freeram),
                       nid, K(node_page_state(nid, NR_ACTIVE_ANON) +
                                node_page_state(nid, NR_ACTIVE_FILE)),
                       nid, K(node_page_state(nid, NR_INACTIVE_ANON) +
                                node_page_state(nid, NR_INACTIVE_FILE)),
                       nid, K(node_page_state(nid, NR_ACTIVE_ANON)),
                       nid, K(node_page_state(nid, NR_INACTIVE_ANON)),
                       nid, K(node_page_state(nid, NR_ACTIVE_FILE)),
                       nid, K(node_page_state(nid, NR_INACTIVE_FILE)),
                       nid, K(node_page_state(nid, NR_UNEVICTABLE)),
                       nid, K(node_page_state(nid, NR_MLOCK)),
#ifdef CONFIG_HIGHMEM
                       nid, K(i.totalhigh),
                       nid, K(i.freehigh),
                       nid, K(i.totalram - i.totalhigh),
                       nid, K(i.freeram - i.freehigh),
#endif
                       nid, K(node_page_state(nid, NR_FILE_DIRTY)),
                       nid, K(node_page_state(nid, NR_WRITEBACK)),
                       nid, K(node_page_state(nid, NR_FILE_PAGES)),
                       nid, K(node_page_state(nid, NR_FILE_MAPPED)),
                       nid, K(node_page_state(nid, NR_ANON_PAGES)),
                       nid, K(node_page_state(nid, NR_SHMEM)),
                       nid, node_page_state(nid, NR_KERNEL_STACK) *
                                THREAD_SIZE / 1024,
                       nid, K(node_page_state(nid, NR_PAGETABLE)),
                       nid, K(node_page_state(nid, NR_UNSTABLE_NFS)),
                       nid, K(node_page_state(nid, NR_BOUNCE)),
                       nid, K(node_page_state(nid, NR_WRITEBACK_TEMP)),
                       nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE) +
                                node_page_state(nid, NR_SLAB_UNRECLAIMABLE)),
                       nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE)),
                       nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE)));
        n += hugetlb_report_node_meminfo(nid, buf + n);
        return n;
}

#undef K
static SYSDEV_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL);

static ssize_t node_read_numastat(struct sys_device * dev,
                                struct sysdev_attribute *attr, char * buf)
{
        return sprintf(buf,
                       "numa_hit %lu\n"
                       "numa_miss %lu\n"
                       "numa_foreign %lu\n"
                       "interleave_hit %lu\n"
                       "local_node %lu\n"
                       "other_node %lu\n",
                       node_page_state(dev->id, NUMA_HIT),
                       node_page_state(dev->id, NUMA_MISS),
                       node_page_state(dev->id, NUMA_FOREIGN),
                       node_page_state(dev->id, NUMA_INTERLEAVE_HIT),
                       node_page_state(dev->id, NUMA_LOCAL),
                       node_page_state(dev->id, NUMA_OTHER));
}
static SYSDEV_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);

static ssize_t node_read_distance(struct sys_device * dev,
                        struct sysdev_attribute *attr, char * buf)
{
        int nid = dev->id;
        int len = 0;
        int i;

        /* buf currently PAGE_SIZE, need ~4 chars per node */
        BUILD_BUG_ON(MAX_NUMNODES*4 > PAGE_SIZE/2);

        for_each_online_node(i)
                len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));

        len += sprintf(buf + len, "\n");
        return len;
}
static SYSDEV_ATTR(distance, S_IRUGO, node_read_distance, NULL);

#ifdef CONFIG_HUGETLBFS
/*
 * hugetlbfs per node attributes registration interface:
 * When/if hugetlb[fs] subsystem initializes [sometime after this module],
 * it will register its per node attributes for all online nodes with
 * memory.  It will also call register_hugetlbfs_with_node(), below, to
 * register its attribute registration functions with this node driver.
 * Once these hooks have been initialized, the node driver will call into
 * the hugetlb module to [un]register attributes for hot-plugged nodes.
 */
static node_registration_func_t __hugetlb_register_node;
static node_registration_func_t __hugetlb_unregister_node;

static inline void hugetlb_register_node(struct node *node)
{
        if (__hugetlb_register_node &&
                        node_state(node->sysdev.id, N_HIGH_MEMORY))
                __hugetlb_register_node(node);
}

static inline void hugetlb_unregister_node(struct node *node)
{
        if (__hugetlb_unregister_node)
                __hugetlb_unregister_node(node);
}

void register_hugetlbfs_with_node(node_registration_func_t doregister,
                                  node_registration_func_t unregister)
{
        __hugetlb_register_node   = doregister;
        __hugetlb_unregister_node = unregister;
}
#else
static inline void hugetlb_register_node(struct node *node) {}

static inline void hugetlb_unregister_node(struct node *node) {}
#endif


/*
 * register_node - Setup a sysfs device for a node.
 * @num - Node number to use when creating the device.
 *
 * Initialize and register the node device.
 */
int register_node(struct node *node, int num, struct node *parent)
{
        int error;

        node->sysdev.id = num;
        node->sysdev.cls = &node_class;
        error = sysdev_register(&node->sysdev);

        if (!error){
                sysdev_create_file(&node->sysdev, &attr_cpumap);
                sysdev_create_file(&node->sysdev, &attr_cpulist);
                sysdev_create_file(&node->sysdev, &attr_meminfo);
                sysdev_create_file(&node->sysdev, &attr_numastat);
                sysdev_create_file(&node->sysdev, &attr_distance);

                scan_unevictable_register_node(node);

                hugetlb_register_node(node);
        }
        return error;
}

/**
 * unregister_node - unregister a node device
 * @node: node going away
 *
 * Unregisters a node device @node.  All the devices on the node must be
 * unregistered before calling this function.
 */
void unregister_node(struct node *node)
{
        sysdev_remove_file(&node->sysdev, &attr_cpumap);
        sysdev_remove_file(&node->sysdev, &attr_cpulist);
        sysdev_remove_file(&node->sysdev, &attr_meminfo);
        sysdev_remove_file(&node->sysdev, &attr_numastat);
        sysdev_remove_file(&node->sysdev, &attr_distance);

        scan_unevictable_unregister_node(node);
        hugetlb_unregister_node(node);          /* no-op, if memoryless node */

        sysdev_unregister(&node->sysdev);
}

struct node node_devices[MAX_NUMNODES];

/*
 * register cpu under node
 */
int register_cpu_under_node(unsigned int cpu, unsigned int nid)
{
        if (node_online(nid)) {
                struct sys_device *obj = get_cpu_sysdev(cpu);
                if (!obj)
                        return 0;
                return sysfs_create_link(&node_devices[nid].sysdev.kobj,
                                         &obj->kobj,
                                         kobject_name(&obj->kobj));
         }

        return 0;
}

int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
{
        if (node_online(nid)) {
                struct sys_device *obj = get_cpu_sysdev(cpu);
                if (obj)
                        sysfs_remove_link(&node_devices[nid].sysdev.kobj,
                                         kobject_name(&obj->kobj));
        }
        return 0;
}

#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
#define page_initialized(page)  (page->lru.next)

static int get_nid_for_pfn(unsigned long pfn)
{
        struct page *page;

        if (!pfn_valid_within(pfn))
                return -1;
        page = pfn_to_page(pfn);
        if (!page_initialized(page))
                return -1;
        return pfn_to_nid(pfn);
}

/* register memory section under specified node if it spans that node */
int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
{
        unsigned long pfn, sect_start_pfn, sect_end_pfn;

        if (!mem_blk)
                return -EFAULT;
        if (!node_online(nid))
                return 0;
        sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
        sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
        for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
                int page_nid;

                page_nid = get_nid_for_pfn(pfn);
                if (page_nid < 0)
                        continue;
                if (page_nid != nid)
                        continue;
                return sysfs_create_link_nowarn(&node_devices[nid].sysdev.kobj,
                                        &mem_blk->sysdev.kobj,
                                        kobject_name(&mem_blk->sysdev.kobj));
        }
        /* mem section does not span the specified node */
        return 0;
}

/* unregister memory section under all nodes that it spans */
int unregister_mem_sect_under_nodes(struct memory_block *mem_blk)
{
        nodemask_t unlinked_nodes;
        unsigned long pfn, sect_start_pfn, sect_end_pfn;

        if (!mem_blk)
                return -EFAULT;
        nodes_clear(unlinked_nodes);
        sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
        sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
        for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
                int nid;

                nid = get_nid_for_pfn(pfn);
                if (nid < 0)
                        continue;
                if (!node_online(nid))
                        continue;
                if (node_test_and_set(nid, unlinked_nodes))
                        continue;
                sysfs_remove_link(&node_devices[nid].sysdev.kobj,
                         kobject_name(&mem_blk->sysdev.kobj));
        }
        return 0;
}

static int link_mem_sections(int nid)
{
        unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
        unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
        unsigned long pfn;
        int err = 0;

        for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
                unsigned long section_nr = pfn_to_section_nr(pfn);
                struct mem_section *mem_sect;
                struct memory_block *mem_blk;
                int ret;

                if (!present_section_nr(section_nr))
                        continue;
                mem_sect = __nr_to_section(section_nr);
                mem_blk = find_memory_block(mem_sect);
                ret = register_mem_sect_under_node(mem_blk, nid);
                if (!err)
                        err = ret;

                /* discard ref obtained in find_memory_block() */
                kobject_put(&mem_blk->sysdev.kobj);
        }
        return err;
}

/*
 * Handle per node hstate attribute [un]registration on transistions
 * to/from memoryless state.
 */

static int node_memory_callback(struct notifier_block *self,
                                unsigned long action, void *arg)
{
        struct memory_notify *mnb = arg;
        int nid = mnb->status_change_nid;

        switch (action) {
        case MEM_ONLINE:    /* memory successfully brought online */
                if (nid != NUMA_NO_NODE)
                        hugetlb_register_node(&node_devices[nid]);
                break;
        case MEM_OFFLINE:   /* or offline */
                if (nid != NUMA_NO_NODE)
                        hugetlb_unregister_node(&node_devices[nid]);
                break;
        case MEM_GOING_ONLINE:
        case MEM_GOING_OFFLINE:
        case MEM_CANCEL_ONLINE:
        case MEM_CANCEL_OFFLINE:
        default:
                break;
        }

        return NOTIFY_OK;
}
#else
static int link_mem_sections(int nid) { return 0; }

static inline int node_memory_callback(struct notifier_block *self,
                                unsigned long action, void *arg)
{
        return NOTIFY_OK;
}
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */

int register_one_node(int nid)
{
        int error = 0;
        int cpu;

        if (node_online(nid)) {
                int p_node = parent_node(nid);
                struct node *parent = NULL;

                if (p_node != nid)
                        parent = &node_devices[p_node];

                error = register_node(&node_devices[nid], nid, parent);

                /* link cpu under this node */
                for_each_present_cpu(cpu) {
                        if (cpu_to_node(cpu) == nid)
                                register_cpu_under_node(cpu, nid);
                }

                /* link memory sections under this node */
                error = link_mem_sections(nid);
        }

        return error;

}

void unregister_one_node(int nid)
{
        unregister_node(&node_devices[nid]);
}

/*
 * node states attributes
 */

static ssize_t print_nodes_state(enum node_states state, char *buf)
{
        int n;

        n = nodelist_scnprintf(buf, PAGE_SIZE, node_states[state]);
        if (n > 0 && PAGE_SIZE > n + 1) {
                *(buf + n++) = '\n';
                *(buf + n++) = '\0';
        }
        return n;
}

static ssize_t print_nodes_possible(struct sysdev_class *class, char *buf)
{
        return print_nodes_state(N_POSSIBLE, buf);
}

static ssize_t print_nodes_online(struct sysdev_class *class, char *buf)
{
        return print_nodes_state(N_ONLINE, buf);
}

static ssize_t print_nodes_has_normal_memory(struct sysdev_class *class,
                                                char *buf)
{
        return print_nodes_state(N_NORMAL_MEMORY, buf);
}

static ssize_t print_nodes_has_cpu(struct sysdev_class *class, char *buf)
{
        return print_nodes_state(N_CPU, buf);
}

static SYSDEV_CLASS_ATTR(possible, 0444, print_nodes_possible, NULL);
static SYSDEV_CLASS_ATTR(online, 0444, print_nodes_online, NULL);
static SYSDEV_CLASS_ATTR(has_normal_memory, 0444, print_nodes_has_normal_memory,
                                                                        NULL);
static SYSDEV_CLASS_ATTR(has_cpu, 0444, print_nodes_has_cpu, NULL);

#ifdef CONFIG_HIGHMEM
static ssize_t print_nodes_has_high_memory(struct sysdev_class *class,
                                                 char *buf)
{
        return print_nodes_state(N_HIGH_MEMORY, buf);
}

static SYSDEV_CLASS_ATTR(has_high_memory, 0444, print_nodes_has_high_memory,
                                                                         NULL);
#endif

struct sysdev_class_attribute *node_state_attr[] = {
        &attr_possible,
        &attr_online,
        &attr_has_normal_memory,
#ifdef CONFIG_HIGHMEM
        &attr_has_high_memory,
#endif
        &attr_has_cpu,
};

static int node_states_init(void)
{
        int i;
        int err = 0;

        for (i = 0;  i < NR_NODE_STATES; i++) {
                int ret;
                ret = sysdev_class_create_file(&node_class, node_state_attr[i]);
                if (!err)
                        err = ret;
        }
        return err;
}

#define NODE_CALLBACK_PRI       2       /* lower than SLAB */
static int __init register_node_type(void)
{
        int ret;

        ret = sysdev_class_register(&node_class);
        if (!ret) {
                ret = node_states_init();
                hotplug_memory_notifier(node_memory_callback,
                                        NODE_CALLBACK_PRI);
        }

        /*
         * Note:  we're not going to unregister the node class if we fail
         * to register the node state class attribute files.
         */
        return ret;
}
postcore_initcall(register_node_type);