Merge branch 'linux-next' of git://git.infradead.org/~dedekind/ubi-2.6

[mirror_ubuntu-artful-kernel.git] / arch / x86 / kernel / cpu / mcheck / mce_amd_64.c

/*
 *  (c) 2005, 2006 Advanced Micro Devices, Inc.
 *  Your use of this code is subject to the terms and conditions of the
 *  GNU general public license version 2. See "COPYING" or
 *  http://www.gnu.org/licenses/gpl.html
 *
 *  Written by Jacob Shin - AMD, Inc.
 *
 *  Support : jacob.shin@amd.com
 *
 *  April 2006
 *     - added support for AMD Family 0x10 processors
 *
 *  All MC4_MISCi registers are shared between multi-cores
 */

#include <linux/cpu.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kobject.h>
#include <linux/notifier.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/sysdev.h>
#include <linux/sysfs.h>
#include <asm/apic.h>
#include <asm/mce.h>
#include <asm/msr.h>
#include <asm/percpu.h>
#include <asm/idle.h>

#define PFX               "mce_threshold: "
#define VERSION           "version 1.1.1"
#define NR_BANKS          6
#define NR_BLOCKS         9
#define THRESHOLD_MAX     0xFFF
#define INT_TYPE_APIC     0x00020000
#define MASK_VALID_HI     0x80000000
#define MASK_CNTP_HI      0x40000000
#define MASK_LOCKED_HI    0x20000000
#define MASK_LVTOFF_HI    0x00F00000
#define MASK_COUNT_EN_HI  0x00080000
#define MASK_INT_TYPE_HI  0x00060000
#define MASK_OVERFLOW_HI  0x00010000
#define MASK_ERR_COUNT_HI 0x00000FFF
#define MASK_BLKPTR_LO    0xFF000000
#define MCG_XBLK_ADDR     0xC0000400

struct threshold_block {
        unsigned int block;
        unsigned int bank;
        unsigned int cpu;
        u32 address;
        u16 interrupt_enable;
        u16 threshold_limit;
        struct kobject kobj;
        struct list_head miscj;
};

/* defaults used early on boot */
static struct threshold_block threshold_defaults = {
        .interrupt_enable = 0,
        .threshold_limit = THRESHOLD_MAX,
};

struct threshold_bank {
        struct kobject *kobj;
        struct threshold_block *blocks;
        cpumask_t cpus;
};
static DEFINE_PER_CPU(struct threshold_bank *, threshold_banks[NR_BANKS]);

#ifdef CONFIG_SMP
static unsigned char shared_bank[NR_BANKS] = {
        0, 0, 0, 0, 1
};
#endif

static DEFINE_PER_CPU(unsigned char, bank_map); /* see which banks are on */

/*
 * CPU Initialization
 */

struct thresh_restart {
        struct threshold_block *b;
        int reset;
        u16 old_limit;
};

/* must be called with correct cpu affinity */
static long threshold_restart_bank(void *_tr)
{
        struct thresh_restart *tr = _tr;
        u32 mci_misc_hi, mci_misc_lo;

        rdmsr(tr->b->address, mci_misc_lo, mci_misc_hi);

        if (tr->b->threshold_limit < (mci_misc_hi & THRESHOLD_MAX))
                tr->reset = 1;  /* limit cannot be lower than err count */

        if (tr->reset) {                /* reset err count and overflow bit */
                mci_misc_hi =
                    (mci_misc_hi & ~(MASK_ERR_COUNT_HI | MASK_OVERFLOW_HI)) |
                    (THRESHOLD_MAX - tr->b->threshold_limit);
        } else if (tr->old_limit) {     /* change limit w/o reset */
                int new_count = (mci_misc_hi & THRESHOLD_MAX) +
                    (tr->old_limit - tr->b->threshold_limit);
                mci_misc_hi = (mci_misc_hi & ~MASK_ERR_COUNT_HI) |
                    (new_count & THRESHOLD_MAX);
        }

        tr->b->interrupt_enable ?
            (mci_misc_hi = (mci_misc_hi & ~MASK_INT_TYPE_HI) | INT_TYPE_APIC) :
            (mci_misc_hi &= ~MASK_INT_TYPE_HI);

        mci_misc_hi |= MASK_COUNT_EN_HI;
        wrmsr(tr->b->address, mci_misc_lo, mci_misc_hi);
        return 0;
}

/* cpu init entry point, called from mce.c with preempt off */
void __cpuinit mce_amd_feature_init(struct cpuinfo_x86 *c)
{
        unsigned int bank, block;
        unsigned int cpu = smp_processor_id();
        u8 lvt_off;
        u32 low = 0, high = 0, address = 0;
        struct thresh_restart tr;

        for (bank = 0; bank < NR_BANKS; ++bank) {
                for (block = 0; block < NR_BLOCKS; ++block) {
                        if (block == 0)
                                address = MSR_IA32_MC0_MISC + bank * 4;
                        else if (block == 1) {
                                address = (low & MASK_BLKPTR_LO) >> 21;
                                if (!address)
                                        break;
                                address += MCG_XBLK_ADDR;
                        }
                        else
                                ++address;

                        if (rdmsr_safe(address, &low, &high))
                                break;

                        if (!(high & MASK_VALID_HI)) {
                                if (block)
                                        continue;
                                else
                                        break;
                        }

                        if (!(high & MASK_CNTP_HI)  ||
                             (high & MASK_LOCKED_HI))
                                continue;

                        if (!block)
                                per_cpu(bank_map, cpu) |= (1 << bank);
#ifdef CONFIG_SMP
                        if (shared_bank[bank] && c->cpu_core_id)
                                break;
#endif
                        lvt_off = setup_APIC_eilvt_mce(THRESHOLD_APIC_VECTOR,
                                                       APIC_EILVT_MSG_FIX, 0);

                        high &= ~MASK_LVTOFF_HI;
                        high |= lvt_off << 20;
                        wrmsr(address, low, high);

                        threshold_defaults.address = address;
                        tr.b = &threshold_defaults;
                        tr.reset = 0;
                        tr.old_limit = 0;
                        threshold_restart_bank(&tr);
                }
        }
}

/*
 * APIC Interrupt Handler
 */

/*
 * threshold interrupt handler will service THRESHOLD_APIC_VECTOR.
 * the interrupt goes off when error_count reaches threshold_limit.
 * the handler will simply log mcelog w/ software defined bank number.
 */
asmlinkage void mce_threshold_interrupt(void)
{
        unsigned int bank, block;
        struct mce m;
        u32 low = 0, high = 0, address = 0;

        ack_APIC_irq();
        exit_idle();
        irq_enter();

        memset(&m, 0, sizeof(m));
        rdtscll(m.tsc);
        m.cpu = smp_processor_id();

        /* assume first bank caused it */
        for (bank = 0; bank < NR_BANKS; ++bank) {
                if (!(per_cpu(bank_map, m.cpu) & (1 << bank)))
                        continue;
                for (block = 0; block < NR_BLOCKS; ++block) {
                        if (block == 0)
                                address = MSR_IA32_MC0_MISC + bank * 4;
                        else if (block == 1) {
                                address = (low & MASK_BLKPTR_LO) >> 21;
                                if (!address)
                                        break;
                                address += MCG_XBLK_ADDR;
                        }
                        else
                                ++address;

                        if (rdmsr_safe(address, &low, &high))
                                break;

                        if (!(high & MASK_VALID_HI)) {
                                if (block)
                                        continue;
                                else
                                        break;
                        }

                        if (!(high & MASK_CNTP_HI)  ||
                             (high & MASK_LOCKED_HI))
                                continue;

                        /* Log the machine check that caused the threshold
                           event. */
                        do_machine_check(NULL, 0);

                        if (high & MASK_OVERFLOW_HI) {
                                rdmsrl(address, m.misc);
                                rdmsrl(MSR_IA32_MC0_STATUS + bank * 4,
                                       m.status);
                                m.bank = K8_MCE_THRESHOLD_BASE
                                       + bank * NR_BLOCKS
                                       + block;
                                mce_log(&m);
                                goto out;
                        }
                }
        }
out:
        inc_irq_stat(irq_threshold_count);
        irq_exit();
}

/*
 * Sysfs Interface
 */

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

#define SHOW_FIELDS(name)                                           \
static ssize_t show_ ## name(struct threshold_block * b, char *buf) \
{                                                                   \
        return sprintf(buf, "%lx\n", (unsigned long) b->name);      \
}
SHOW_FIELDS(interrupt_enable)
SHOW_FIELDS(threshold_limit)

static ssize_t store_interrupt_enable(struct threshold_block *b,
                                      const char *buf, size_t count)
{
        char *end;
        struct thresh_restart tr;
        unsigned long new = simple_strtoul(buf, &end, 0);
        if (end == buf)
                return -EINVAL;
        b->interrupt_enable = !!new;

        tr.b = b;
        tr.reset = 0;
        tr.old_limit = 0;
        work_on_cpu(b->cpu, threshold_restart_bank, &tr);

        return end - buf;
}

static ssize_t store_threshold_limit(struct threshold_block *b,
                                     const char *buf, size_t count)
{
        char *end;
        struct thresh_restart tr;
        unsigned long new = simple_strtoul(buf, &end, 0);
        if (end == buf)
                return -EINVAL;
        if (new > THRESHOLD_MAX)
                new = THRESHOLD_MAX;
        if (new < 1)
                new = 1;
        tr.old_limit = b->threshold_limit;
        b->threshold_limit = new;
        tr.b = b;
        tr.reset = 0;

        work_on_cpu(b->cpu, threshold_restart_bank, &tr);

        return end - buf;
}

static long local_error_count(void *_b)
{
        struct threshold_block *b = _b;
        u32 low, high;

        rdmsr(b->address, low, high);
        return (high & 0xFFF) - (THRESHOLD_MAX - b->threshold_limit);
}

static ssize_t show_error_count(struct threshold_block *b, char *buf)
{
        return sprintf(buf, "%lx\n", work_on_cpu(b->cpu, local_error_count, b));
}

static ssize_t store_error_count(struct threshold_block *b,
                                 const char *buf, size_t count)
{
        struct thresh_restart tr = { .b = b, .reset = 1, .old_limit = 0 };

        work_on_cpu(b->cpu, threshold_restart_bank, &tr);
        return 1;
}

#define THRESHOLD_ATTR(_name,_mode,_show,_store) {            \
        .attr = {.name = __stringify(_name), .mode = _mode }, \
        .show = _show,                                        \
        .store = _store,                                      \
};

#define RW_ATTR(name)                                           \
static struct threshold_attr name =                             \
        THRESHOLD_ATTR(name, 0644, show_## name, store_## name)

RW_ATTR(interrupt_enable);
RW_ATTR(threshold_limit);
RW_ATTR(error_count);

static struct attribute *default_attrs[] = {
        &interrupt_enable.attr,
        &threshold_limit.attr,
        &error_count.attr,
        NULL
};

#define to_block(k) container_of(k, struct threshold_block, kobj)
#define to_attr(a) container_of(a, struct threshold_attr, attr)

static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
{
        struct threshold_block *b = to_block(kobj);
        struct threshold_attr *a = to_attr(attr);
        ssize_t ret;
        ret = a->show ? a->show(b, buf) : -EIO;
        return ret;
}

static ssize_t store(struct kobject *kobj, struct attribute *attr,
                     const char *buf, size_t count)
{
        struct threshold_block *b = to_block(kobj);
        struct threshold_attr *a = to_attr(attr);
        ssize_t ret;
        ret = a->store ? a->store(b, buf, count) : -EIO;
        return ret;
}

static struct sysfs_ops threshold_ops = {
        .show = show,
        .store = store,
};

static struct kobj_type threshold_ktype = {
        .sysfs_ops = &threshold_ops,
        .default_attrs = default_attrs,
};

static __cpuinit int allocate_threshold_blocks(unsigned int cpu,
                                               unsigned int bank,
                                               unsigned int block,
                                               u32 address)
{
        int err;
        u32 low, high;
        struct threshold_block *b = NULL;

        if ((bank >= NR_BANKS) || (block >= NR_BLOCKS))
                return 0;

        if (rdmsr_safe(address, &low, &high))
                return 0;

        if (!(high & MASK_VALID_HI)) {
                if (block)
                        goto recurse;
                else
                        return 0;
        }

        if (!(high & MASK_CNTP_HI)  ||
             (high & MASK_LOCKED_HI))
                goto recurse;

        b = kzalloc(sizeof(struct threshold_block), GFP_KERNEL);
        if (!b)
                return -ENOMEM;

        b->block = block;
        b->bank = bank;
        b->cpu = cpu;
        b->address = address;
        b->interrupt_enable = 0;
        b->threshold_limit = THRESHOLD_MAX;

        INIT_LIST_HEAD(&b->miscj);

        if (per_cpu(threshold_banks, cpu)[bank]->blocks)
                list_add(&b->miscj,
                         &per_cpu(threshold_banks, cpu)[bank]->blocks->miscj);
        else
                per_cpu(threshold_banks, cpu)[bank]->blocks = b;

        err = kobject_init_and_add(&b->kobj, &threshold_ktype,
                                   per_cpu(threshold_banks, cpu)[bank]->kobj,
                                   "misc%i", block);
        if (err)
                goto out_free;
recurse:
        if (!block) {
                address = (low & MASK_BLKPTR_LO) >> 21;
                if (!address)
                        return 0;
                address += MCG_XBLK_ADDR;
        } else
                ++address;

        err = allocate_threshold_blocks(cpu, bank, ++block, address);
        if (err)
                goto out_free;

        if (b)
                kobject_uevent(&b->kobj, KOBJ_ADD);

        return err;

out_free:
        if (b) {
                kobject_put(&b->kobj);
                kfree(b);
        }
        return err;
}

static long local_allocate_threshold_blocks(void *_bank)
{
        unsigned int *bank = _bank;

        return allocate_threshold_blocks(smp_processor_id(), *bank, 0,
                                         MSR_IA32_MC0_MISC + *bank * 4);
}

/* symlinks sibling shared banks to first core.  first core owns dir/files. */
static __cpuinit int threshold_create_bank(unsigned int cpu, unsigned int bank)
{
        int i, err = 0;
        struct threshold_bank *b = NULL;
        char name[32];

        sprintf(name, "threshold_bank%i", bank);

#ifdef CONFIG_SMP
        if (cpu_data(cpu).cpu_core_id && shared_bank[bank]) {   /* symlink */
                i = first_cpu(per_cpu(cpu_core_map, cpu));

                /* first core not up yet */
                if (cpu_data(i).cpu_core_id)
                        goto out;

                /* already linked */
                if (per_cpu(threshold_banks, cpu)[bank])
                        goto out;

                b = per_cpu(threshold_banks, i)[bank];

                if (!b)
                        goto out;

                err = sysfs_create_link(&per_cpu(device_mce, cpu).kobj,
                                        b->kobj, name);
                if (err)
                        goto out;

                b->cpus = per_cpu(cpu_core_map, cpu);
                per_cpu(threshold_banks, cpu)[bank] = b;
                goto out;
        }
#endif

        b = kzalloc(sizeof(struct threshold_bank), GFP_KERNEL);
        if (!b) {
                err = -ENOMEM;
                goto out;
        }

        b->kobj = kobject_create_and_add(name, &per_cpu(device_mce, cpu).kobj);
        if (!b->kobj)
                goto out_free;

#ifndef CONFIG_SMP
        b->cpus = CPU_MASK_ALL;
#else
        b->cpus = per_cpu(cpu_core_map, cpu);
#endif

        per_cpu(threshold_banks, cpu)[bank] = b;

        err = work_on_cpu(cpu, local_allocate_threshold_blocks, &bank);
        if (err)
                goto out_free;

        for_each_cpu_mask_nr(i, b->cpus) {
                if (i == cpu)
                        continue;

                err = sysfs_create_link(&per_cpu(device_mce, i).kobj,
                                        b->kobj, name);
                if (err)
                        goto out;

                per_cpu(threshold_banks, i)[bank] = b;
        }

        goto out;

out_free:
        per_cpu(threshold_banks, cpu)[bank] = NULL;
        kfree(b);
out:
        return err;
}

/* create dir/files for all valid threshold banks */
static __cpuinit int threshold_create_device(unsigned int cpu)
{
        unsigned int bank;
        int err = 0;

        for (bank = 0; bank < NR_BANKS; ++bank) {
                if (!(per_cpu(bank_map, cpu) & (1 << bank)))
                        continue;
                err = threshold_create_bank(cpu, bank);
                if (err)
                        goto out;
        }
out:
        return err;
}

/*
 * let's be hotplug friendly.
 * in case of multiple core processors, the first core always takes ownership
 *   of shared sysfs dir/files, and rest of the cores will be symlinked to it.
 */

static void deallocate_threshold_block(unsigned int cpu,
                                                 unsigned int bank)
{
        struct threshold_block *pos = NULL;
        struct threshold_block *tmp = NULL;
        struct threshold_bank *head = per_cpu(threshold_banks, cpu)[bank];

        if (!head)
                return;

        list_for_each_entry_safe(pos, tmp, &head->blocks->miscj, miscj) {
                kobject_put(&pos->kobj);
                list_del(&pos->miscj);
                kfree(pos);
        }

        kfree(per_cpu(threshold_banks, cpu)[bank]->blocks);
        per_cpu(threshold_banks, cpu)[bank]->blocks = NULL;
}

static void threshold_remove_bank(unsigned int cpu, int bank)
{
        int i = 0;
        struct threshold_bank *b;
        char name[32];

        b = per_cpu(threshold_banks, cpu)[bank];

        if (!b)
                return;

        if (!b->blocks)
                goto free_out;

        sprintf(name, "threshold_bank%i", bank);

#ifdef CONFIG_SMP
        /* sibling symlink */
        if (shared_bank[bank] && b->blocks->cpu != cpu) {
                sysfs_remove_link(&per_cpu(device_mce, cpu).kobj, name);
                per_cpu(threshold_banks, cpu)[bank] = NULL;
                return;
        }
#endif

        /* remove all sibling symlinks before unregistering */
        for_each_cpu_mask_nr(i, b->cpus) {
                if (i == cpu)
                        continue;

                sysfs_remove_link(&per_cpu(device_mce, i).kobj, name);
                per_cpu(threshold_banks, i)[bank] = NULL;
        }

        deallocate_threshold_block(cpu, bank);

free_out:
        kobject_del(b->kobj);
        kobject_put(b->kobj);
        kfree(b);
        per_cpu(threshold_banks, cpu)[bank] = NULL;
}

static void threshold_remove_device(unsigned int cpu)
{
        unsigned int bank;

        for (bank = 0; bank < NR_BANKS; ++bank) {
                if (!(per_cpu(bank_map, cpu) & (1 << bank)))
                        continue;
                threshold_remove_bank(cpu, bank);
        }
}

/* get notified when a cpu comes on/off */
static void __cpuinit amd_64_threshold_cpu_callback(unsigned long action,
                                                     unsigned int cpu)
{
        if (cpu >= NR_CPUS)
                return;

        switch (action) {
        case CPU_ONLINE:
        case CPU_ONLINE_FROZEN:
                threshold_create_device(cpu);
                break;
        case CPU_DEAD:
        case CPU_DEAD_FROZEN:
                threshold_remove_device(cpu);
                break;
        default:
                break;
        }
}

static __init int threshold_init_device(void)
{
        unsigned lcpu = 0;

        /* to hit CPUs online before the notifier is up */
        for_each_online_cpu(lcpu) {
                int err = threshold_create_device(lcpu);
                if (err)
                        return err;
        }
        threshold_cpu_callback = amd_64_threshold_cpu_callback;
        return 0;
}

device_initcall(threshold_init_device);