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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
 */

/* must be called with correct cpu affinity */
static void threshold_restart_bank(struct threshold_block *b,
                           int reset, u16 old_limit)
{
      u32 mci_misc_hi, mci_misc_lo;

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

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

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

      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(b->address, mci_misc_lo, mci_misc_hi);
}

/* 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();
      u32 low = 0, high = 0, address = 0;

      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
                  high &= ~MASK_LVTOFF_HI;
                  high |= K8_APIC_EXT_LVT_ENTRY_THRESHOLD << 20;
                  wrmsr(address, low, high);

                  setup_APIC_extended_lvt(K8_APIC_EXT_LVT_ENTRY_THRESHOLD,
                                    THRESHOLD_APIC_VECTOR,
                                    K8_APIC_EXT_INT_MSG_FIX, 0);

                  threshold_defaults.address = address;
                  threshold_restart_bank(&threshold_defaults, 0, 0);
            }
      }
}

/*
 * 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:
      add_pda(irq_threshold_count, 1);
      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);
};

static cpumask_t affinity_set(unsigned int cpu)
{
      cpumask_t oldmask = current->cpus_allowed;
      cpumask_t newmask = CPU_MASK_NONE;
      cpu_set(cpu, newmask);
      set_cpus_allowed(current, newmask);
      return oldmask;
}

static void affinity_restore(cpumask_t oldmask)
{
      set_cpus_allowed(current, oldmask);
}

#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;
      cpumask_t oldmask;
      unsigned long new = simple_strtoul(buf, &end, 0);
      if (end == buf)
            return -EINVAL;
      b->interrupt_enable = !!new;

      oldmask = affinity_set(b->cpu);
      threshold_restart_bank(b, 0, 0);
      affinity_restore(oldmask);

      return end - buf;
}

static ssize_t store_threshold_limit(struct threshold_block *b,
                             const char *buf, size_t count)
{
      char *end;
      cpumask_t oldmask;
      u16 old;
      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;
      old = b->threshold_limit;
      b->threshold_limit = new;

      oldmask = affinity_set(b->cpu);
      threshold_restart_bank(b, 0, old);
      affinity_restore(oldmask);

      return end - buf;
}

static ssize_t show_error_count(struct threshold_block *b, char *buf)
{
      u32 high, low;
      cpumask_t oldmask;
      oldmask = affinity_set(b->cpu);
      rdmsr(b->address, low, high);
      affinity_restore(oldmask);
      return sprintf(buf, "%x\n",
                   (high & 0xFFF) - (THRESHOLD_MAX - b->threshold_limit));
}

static ssize_t store_error_count(struct threshold_block *b,
                         const char *buf, size_t count)
{
      cpumask_t oldmask;
      oldmask = affinity_set(b->cpu);
      threshold_restart_bank(b, 1, 0);
      affinity_restore(oldmask);
      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;

      kobject_set_name(&b->kobj, "misc%i", block);
      b->kobj.parent = &per_cpu(threshold_banks, cpu)[bank]->kobj;
      b->kobj.ktype = &threshold_ktype;
      err = kobject_register(&b->kobj);
      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;

      return err;

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

/* 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;
      cpumask_t oldmask = CPU_MASK_NONE;
      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;
      }

      kobject_set_name(&b->kobj, "threshold_bank%i", bank);
      b->kobj.parent = &per_cpu(device_mce, cpu).kobj;
#ifndef CONFIG_SMP
      b->cpus = CPU_MASK_ALL;
#else
      b->cpus = per_cpu(cpu_core_map, cpu);
#endif
      err = kobject_register(&b->kobj);
      if (err)
            goto out_free;

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

      oldmask = affinity_set(cpu);
      err = allocate_threshold_blocks(cpu, bank, 0,
                              MSR_IA32_MC0_MISC + bank * 4);
      affinity_restore(oldmask);

      if (err)
            goto out_free;

      for_each_cpu_mask(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_unregister(&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(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_unregister(&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 int threshold_cpu_callback(struct notifier_block *nfb,
                                  unsigned long action, void *hcpu)
{
      /* cpu was unsigned int to begin with */
      unsigned int cpu = (unsigned long)hcpu;

      if (cpu >= NR_CPUS)
            goto out;

      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;
      }
      out:
      return NOTIFY_OK;
}

static struct notifier_block threshold_cpu_notifier = {
      .notifier_call = threshold_cpu_callback,
};

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;
      }
      register_hotcpu_notifier(&threshold_cpu_notifier);
      return 0;
}

device_initcall(threshold_init_device);

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