topology.c

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/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * This file contains NUMA specific variables and functions which can
 * be split away from DISCONTIGMEM and are used on NUMA machines with
 * contiguous memory.
 *      2002/08/07 Erich Focht <[email protected]>
 * Populate cpu entries in sysfs for non-numa systems as well
 *      Intel Corporation - Ashok Raj
 * 02/27/2006 Zhang, Yanmin
 *  Populate cpu cache entries in sysfs for cpu cache info
 */

#include <linux/cpu.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/node.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/nodemask.h>
#include <linux/notifier.h>
#include <linux/export.h>
#include <asm/mmzone.h>
#include <asm/numa.h>
#include <asm/cpu.h>

static struct ia64_cpu *sysfs_cpus;

void arch_fix_phys_package_id(int num, u32 slot)
{
#ifdef CONFIG_SMP
    if (cpu_data(num)->socket_id == -1)
        cpu_data(num)->socket_id = slot;
#endif
}
EXPORT_SYMBOL_GPL(arch_fix_phys_package_id);


#ifdef CONFIG_HOTPLUG_CPU
int __ref arch_register_cpu(int num)
{
#ifdef CONFIG_ACPI
    /*
     * If CPEI can be re-targeted or if this is not
     * CPEI target, then it is hotpluggable
     */
    if (can_cpei_retarget() || !is_cpu_cpei_target(num))
        sysfs_cpus[num].cpu.hotpluggable = 1;
    map_cpu_to_node(num, node_cpuid[num].nid);
#endif
    return register_cpu(&sysfs_cpus[num].cpu, num);
}
EXPORT_SYMBOL(arch_register_cpu);

void __ref arch_unregister_cpu(int num)
{
    unregister_cpu(&sysfs_cpus[num].cpu);
#ifdef CONFIG_ACPI
    unmap_cpu_from_node(num, cpu_to_node(num));
#endif
}
EXPORT_SYMBOL(arch_unregister_cpu);
#else
static int __init arch_register_cpu(int num)
{
    return register_cpu(&sysfs_cpus[num].cpu, num);
}
#endif /*CONFIG_HOTPLUG_CPU*/


static int __init topology_init(void)
{
    int i, err = 0;

#ifdef CONFIG_NUMA
    /*
     * MCD - Do we want to register all ONLINE nodes, or all POSSIBLE nodes?
     */
    for_each_online_node(i) {
        if ((err = register_one_node(i)))
            goto out;
    }
#endif

    sysfs_cpus = kzalloc(sizeof(struct ia64_cpu) * NR_CPUS, GFP_KERNEL);
    if (!sysfs_cpus)
        panic("kzalloc in topology_init failed - NR_CPUS too big?");

    for_each_present_cpu(i) {
        if((err = arch_register_cpu(i)))
            goto out;
    }
out:
    return err;
}

subsys_initcall(topology_init);


/*
 * Export cpu cache information through sysfs
 */

/*
 *  A bunch of string array to get pretty printing
 */
static const char *cache_types[] = {
    "",         /* not used */
    "Instruction",
    "Data",
    "Unified"   /* unified */
};

static const char *cache_mattrib[]={
    "WriteThrough",
    "WriteBack",
    "",     /* reserved */
    ""      /* reserved */
};

struct cache_info {
    pal_cache_config_info_t cci;
    cpumask_t shared_cpu_map;
    int level;
    int type;
    struct kobject kobj;
};

struct cpu_cache_info {
    struct cache_info *cache_leaves;
    int num_cache_leaves;
    struct kobject kobj;
};

static struct cpu_cache_info    all_cpu_cache_info[NR_CPUS] __cpuinitdata;
#define LEAF_KOBJECT_PTR(x,y)    (&all_cpu_cache_info[x].cache_leaves[y])

#ifdef CONFIG_SMP
static void __cpuinit cache_shared_cpu_map_setup( unsigned int cpu,
        struct cache_info * this_leaf)
{
    pal_cache_shared_info_t csi;
    int num_shared, i = 0;
    unsigned int j;

    if (cpu_data(cpu)->threads_per_core <= 1 &&
        cpu_data(cpu)->cores_per_socket <= 1) {
        cpu_set(cpu, this_leaf->shared_cpu_map);
        return;
    }

    if (ia64_pal_cache_shared_info(this_leaf->level,
                    this_leaf->type,
                    0,
                    &csi) != PAL_STATUS_SUCCESS)
        return;

    num_shared = (int) csi.num_shared;
    do {
        for_each_possible_cpu(j)
            if (cpu_data(cpu)->socket_id == cpu_data(j)->socket_id
                && cpu_data(j)->core_id == csi.log1_cid
                && cpu_data(j)->thread_id == csi.log1_tid)
                cpu_set(j, this_leaf->shared_cpu_map);

        i++;
    } while (i < num_shared &&
        ia64_pal_cache_shared_info(this_leaf->level,
                this_leaf->type,
                i,
                &csi) == PAL_STATUS_SUCCESS);
}
#else
static void __cpuinit cache_shared_cpu_map_setup(unsigned int cpu,
        struct cache_info * this_leaf)
{
    cpu_set(cpu, this_leaf->shared_cpu_map);
    return;
}
#endif

static ssize_t show_coherency_line_size(struct cache_info *this_leaf,
                    char *buf)
{
    return sprintf(buf, "%u\n", 1 << this_leaf->cci.pcci_line_size);
}

static ssize_t show_ways_of_associativity(struct cache_info *this_leaf,
                    char *buf)
{
    return sprintf(buf, "%u\n", this_leaf->cci.pcci_assoc);
}

static ssize_t show_attributes(struct cache_info *this_leaf, char *buf)
{
    return sprintf(buf,
            "%s\n",
            cache_mattrib[this_leaf->cci.pcci_cache_attr]);
}

static ssize_t show_size(struct cache_info *this_leaf, char *buf)
{
    return sprintf(buf, "%uK\n", this_leaf->cci.pcci_cache_size / 1024);
}

static ssize_t show_number_of_sets(struct cache_info *this_leaf, char *buf)
{
    unsigned number_of_sets = this_leaf->cci.pcci_cache_size;
    number_of_sets /= this_leaf->cci.pcci_assoc;
    number_of_sets /= 1 << this_leaf->cci.pcci_line_size;

    return sprintf(buf, "%u\n", number_of_sets);
}

static ssize_t show_shared_cpu_map(struct cache_info *this_leaf, char *buf)
{
    ssize_t len;
    cpumask_t shared_cpu_map;

    cpumask_and(&shared_cpu_map,
                &this_leaf->shared_cpu_map, cpu_online_mask);
    len = cpumask_scnprintf(buf, NR_CPUS+1, &shared_cpu_map);
    len += sprintf(buf+len, "\n");
    return len;
}

static ssize_t show_type(struct cache_info *this_leaf, char *buf)
{
    int type = this_leaf->type + this_leaf->cci.pcci_unified;
    return sprintf(buf, "%s\n", cache_types[type]);
}

static ssize_t show_level(struct cache_info *this_leaf, char *buf)
{
    return sprintf(buf, "%u\n", this_leaf->level);
}

struct cache_attr {
    struct attribute attr;
    ssize_t (*show)(struct cache_info *, char *);
    ssize_t (*store)(struct cache_info *, const char *, size_t count);
};

#ifdef define_one_ro
    #undef define_one_ro
#endif
#define define_one_ro(_name) \
    static struct cache_attr _name = \
__ATTR(_name, 0444, show_##_name, NULL)

define_one_ro(level);
define_one_ro(type);
define_one_ro(coherency_line_size);
define_one_ro(ways_of_associativity);
define_one_ro(size);
define_one_ro(number_of_sets);
define_one_ro(shared_cpu_map);
define_one_ro(attributes);

static struct attribute * cache_default_attrs[] = {
    &type.attr,
    &level.attr,
    &coherency_line_size.attr,
    &ways_of_associativity.attr,
    &attributes.attr,
    &size.attr,
    &number_of_sets.attr,
    &shared_cpu_map.attr,
    NULL
};

#define to_object(k) container_of(k, struct cache_info, kobj)
#define to_attr(a) container_of(a, struct cache_attr, attr)

static ssize_t cache_show(struct kobject * kobj, struct attribute * attr, char * buf)
{
    struct cache_attr *fattr = to_attr(attr);
    struct cache_info *this_leaf = to_object(kobj);
    ssize_t ret;

    ret = fattr->show ? fattr->show(this_leaf, buf) : 0;
    return ret;
}

static const struct sysfs_ops cache_sysfs_ops = {
    .show   = cache_show
};

static struct kobj_type cache_ktype = {
    .sysfs_ops  = &cache_sysfs_ops,
    .default_attrs  = cache_default_attrs,
};

static struct kobj_type cache_ktype_percpu_entry = {
    .sysfs_ops  = &cache_sysfs_ops,
};

static void __cpuinit cpu_cache_sysfs_exit(unsigned int cpu)
{
    kfree(all_cpu_cache_info[cpu].cache_leaves);
    all_cpu_cache_info[cpu].cache_leaves = NULL;
    all_cpu_cache_info[cpu].num_cache_leaves = 0;
    memset(&all_cpu_cache_info[cpu].kobj, 0, sizeof(struct kobject));
    return;
}

static int __cpuinit cpu_cache_sysfs_init(unsigned int cpu)
{
    unsigned long i, levels, unique_caches;
    pal_cache_config_info_t cci;
    int j;
    long status;
    struct cache_info *this_cache;
    int num_cache_leaves = 0;

    if ((status = ia64_pal_cache_summary(&levels, &unique_caches)) != 0) {
        printk(KERN_ERR "ia64_pal_cache_summary=%ld\n", status);
        return -1;
    }

    this_cache=kzalloc(sizeof(struct cache_info)*unique_caches,
            GFP_KERNEL);
    if (this_cache == NULL)
        return -ENOMEM;

    for (i=0; i < levels; i++) {
        for (j=2; j >0 ; j--) {
            if ((status=ia64_pal_cache_config_info(i,j, &cci)) !=
                    PAL_STATUS_SUCCESS)
                continue;

            this_cache[num_cache_leaves].cci = cci;
            this_cache[num_cache_leaves].level = i + 1;
            this_cache[num_cache_leaves].type = j;

            cache_shared_cpu_map_setup(cpu,
                    &this_cache[num_cache_leaves]);
            num_cache_leaves ++;
        }
    }

    all_cpu_cache_info[cpu].cache_leaves = this_cache;
    all_cpu_cache_info[cpu].num_cache_leaves = num_cache_leaves;

    memset(&all_cpu_cache_info[cpu].kobj, 0, sizeof(struct kobject));

    return 0;
}

/* Add cache interface for CPU device */
static int __cpuinit cache_add_dev(struct device * sys_dev)
{
    unsigned int cpu = sys_dev->id;
    unsigned long i, j;
    struct cache_info *this_object;
    int retval = 0;
    cpumask_t oldmask;

    if (all_cpu_cache_info[cpu].kobj.parent)
        return 0;

    oldmask = current->cpus_allowed;
    retval = set_cpus_allowed_ptr(current, cpumask_of(cpu));
    if (unlikely(retval))
        return retval;

    retval = cpu_cache_sysfs_init(cpu);
    set_cpus_allowed_ptr(current, &oldmask);
    if (unlikely(retval < 0))
        return retval;

    retval = kobject_init_and_add(&all_cpu_cache_info[cpu].kobj,
                      &cache_ktype_percpu_entry, &sys_dev->kobj,
                      "%s", "cache");
    if (unlikely(retval < 0)) {
        cpu_cache_sysfs_exit(cpu);
        return retval;
    }

    for (i = 0; i < all_cpu_cache_info[cpu].num_cache_leaves; i++) {
        this_object = LEAF_KOBJECT_PTR(cpu,i);
        retval = kobject_init_and_add(&(this_object->kobj),
                          &cache_ktype,
                          &all_cpu_cache_info[cpu].kobj,
                          "index%1lu", i);
        if (unlikely(retval)) {
            for (j = 0; j < i; j++) {
                kobject_put(&(LEAF_KOBJECT_PTR(cpu,j)->kobj));
            }
            kobject_put(&all_cpu_cache_info[cpu].kobj);
            cpu_cache_sysfs_exit(cpu);
            return retval;
        }
        kobject_uevent(&(this_object->kobj), KOBJ_ADD);
    }
    kobject_uevent(&all_cpu_cache_info[cpu].kobj, KOBJ_ADD);
    return retval;
}

/* Remove cache interface for CPU device */
static int __cpuinit cache_remove_dev(struct device * sys_dev)
{
    unsigned int cpu = sys_dev->id;
    unsigned long i;

    for (i = 0; i < all_cpu_cache_info[cpu].num_cache_leaves; i++)
        kobject_put(&(LEAF_KOBJECT_PTR(cpu,i)->kobj));

    if (all_cpu_cache_info[cpu].kobj.parent) {
        kobject_put(&all_cpu_cache_info[cpu].kobj);
        memset(&all_cpu_cache_info[cpu].kobj,
            0,
            sizeof(struct kobject));
    }

    cpu_cache_sysfs_exit(cpu);

    return 0;
}

/*
 * When a cpu is hot-plugged, do a check and initiate
 * cache kobject if necessary
 */
static int __cpuinit cache_cpu_callback(struct notifier_block *nfb,
        unsigned long action, void *hcpu)
{
    unsigned int cpu = (unsigned long)hcpu;
    struct device *sys_dev;

    sys_dev = get_cpu_device(cpu);
    switch (action) {
    case CPU_ONLINE:
    case CPU_ONLINE_FROZEN:
        cache_add_dev(sys_dev);
        break;
    case CPU_DEAD:
    case CPU_DEAD_FROZEN:
        cache_remove_dev(sys_dev);
        break;
    }
    return NOTIFY_OK;
}

static struct notifier_block __cpuinitdata cache_cpu_notifier =
{
    .notifier_call = cache_cpu_callback
};

static int __init cache_sysfs_init(void)
{
    int i;

    for_each_online_cpu(i) {
        struct device *sys_dev = get_cpu_device((unsigned int)i);
        cache_add_dev(sys_dev);
    }

    register_hotcpu_notifier(&cache_cpu_notifier);

    return 0;
}

device_initcall(cache_sysfs_init);