/*
 *  (c) 2005-2016 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.
 *  Maintained by: Borislav Petkov <bp@alien8.de>
 *
 *  All MC4_MISCi registers are shared between cores on a node.
 */
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/kobject.h>
#include <linux/percpu.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/smp.h>
#include <linux/string.h>

#include <asm/amd_nb.h>
#include <asm/traps.h>
#include <asm/apic.h>
#include <asm/mce.h>
#include <asm/msr.h>
#include <asm/trace/irq_vectors.h>

#include "internal.h"

#define NR_BLOCKS         5
#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

/* Deferred error settings */
#define MSR_CU_DEF_ERR          0xC0000410
#define MASK_DEF_LVTOFF         0x000000F0
#define MASK_DEF_INT_TYPE       0x00000006
#define DEF_LVT_OFF             0x2
#define DEF_INT_TYPE_APIC       0x2

/* Scalable MCA: */

/* Threshold LVT offset is at MSR0xC0000410[15:12] */
#define SMCA_THR_LVT_OFF        0xF000

static bool thresholding_irq_en;

static const char * const th_names[] = {
        "load_store",
        "insn_fetch",
        "combined_unit",
        "decode_unit",
        "northbridge",
        "execution_unit",
};

static const char * const smca_umc_block_names[] = {
        "dram_ecc",
        "misc_umc"
};

#define HWID_MCATYPE(hwid, mcatype) (((hwid) << 16) | (mcatype))

struct smca_hwid {
        unsigned int bank_type; /* Use with smca_bank_types for easy indexing. */
        u32 hwid_mcatype;       /* (hwid,mcatype) tuple */
};

struct smca_bank {
        const struct smca_hwid *hwid;
        u32 id;                 /* Value of MCA_IPID[InstanceId]. */
        u8 sysfs_id;            /* Value used for sysfs name. */
};

static DEFINE_PER_CPU_READ_MOSTLY(struct smca_bank[MAX_NR_BANKS], smca_banks);
static DEFINE_PER_CPU_READ_MOSTLY(u8[N_SMCA_BANK_TYPES], smca_bank_counts);

struct smca_bank_name {
        const char *name;       /* Short name for sysfs */
        const char *long_name;  /* Long name for pretty-printing */
};

static struct smca_bank_name smca_names[] = {
        [SMCA_LS ... SMCA_LS_V2]        = { "load_store",       "Load Store Unit" },
        [SMCA_IF]                       = { "insn_fetch",       "Instruction Fetch Unit" },
        [SMCA_L2_CACHE]                 = { "l2_cache",         "L2 Cache" },
        [SMCA_DE]                       = { "decode_unit",      "Decode Unit" },
        [SMCA_RESERVED]                 = { "reserved",         "Reserved" },
        [SMCA_EX]                       = { "execution_unit",   "Execution Unit" },
        [SMCA_FP]                       = { "floating_point",   "Floating Point Unit" },
        [SMCA_L3_CACHE]                 = { "l3_cache",         "L3 Cache" },
        [SMCA_CS ... SMCA_CS_V2]        = { "coherent_slave",   "Coherent Slave" },
        [SMCA_PIE]                      = { "pie",              "Power, Interrupts, etc." },

        /* UMC v2 is separate because both of them can exist in a single system. */
        [SMCA_UMC]                      = { "umc",              "Unified Memory Controller" },
        [SMCA_UMC_V2]                   = { "umc_v2",           "Unified Memory Controller v2" },
        [SMCA_PB]                       = { "param_block",      "Parameter Block" },
        [SMCA_PSP ... SMCA_PSP_V2]      = { "psp",              "Platform Security Processor" },
        [SMCA_SMU ... SMCA_SMU_V2]      = { "smu",              "System Management Unit" },
        [SMCA_MP5]                      = { "mp5",              "Microprocessor 5 Unit" },
        [SMCA_MPDMA]                    = { "mpdma",            "MPDMA Unit" },
        [SMCA_NBIO]                     = { "nbio",             "Northbridge IO Unit" },
        [SMCA_PCIE ... SMCA_PCIE_V2]    = { "pcie",             "PCI Express Unit" },
        [SMCA_XGMI_PCS]                 = { "xgmi_pcs",         "Ext Global Memory Interconnect PCS Unit" },
        [SMCA_NBIF]                     = { "nbif",             "NBIF Unit" },
        [SMCA_SHUB]                     = { "shub",             "System Hub Unit" },
        [SMCA_SATA]                     = { "sata",             "SATA Unit" },
        [SMCA_USB]                      = { "usb",              "USB Unit" },
        [SMCA_GMI_PCS]                  = { "gmi_pcs",          "Global Memory Interconnect PCS Unit" },
        [SMCA_XGMI_PHY]                 = { "xgmi_phy",         "Ext Global Memory Interconnect PHY Unit" },
        [SMCA_WAFL_PHY]                 = { "wafl_phy",         "WAFL PHY Unit" },
        [SMCA_GMI_PHY]                  = { "gmi_phy",          "Global Memory Interconnect PHY Unit" },
};

static const char *smca_get_name(enum smca_bank_types t)
{
        if (t >= N_SMCA_BANK_TYPES)
                return NULL;

        return smca_names[t].name;
}

const char *smca_get_long_name(enum smca_bank_types t)
{
        if (t >= N_SMCA_BANK_TYPES)
                return NULL;

        return smca_names[t].long_name;
}
EXPORT_SYMBOL_GPL(smca_get_long_name);

enum smca_bank_types smca_get_bank_type(unsigned int cpu, unsigned int bank)
{
        struct smca_bank *b;

        if (bank >= MAX_NR_BANKS)
                return N_SMCA_BANK_TYPES;

        b = &per_cpu(smca_banks, cpu)[bank];
        if (!b->hwid)
                return N_SMCA_BANK_TYPES;

        return b->hwid->bank_type;
}
EXPORT_SYMBOL_GPL(smca_get_bank_type);

static const struct smca_hwid smca_hwid_mcatypes[] = {
        /* { bank_type, hwid_mcatype } */

        /* Reserved type */
        { SMCA_RESERVED, HWID_MCATYPE(0x00, 0x0)        },

        /* ZN Core (HWID=0xB0) MCA types */
        { SMCA_LS,       HWID_MCATYPE(0xB0, 0x0)        },
        { SMCA_LS_V2,    HWID_MCATYPE(0xB0, 0x10)       },
        { SMCA_IF,       HWID_MCATYPE(0xB0, 0x1)        },
        { SMCA_L2_CACHE, HWID_MCATYPE(0xB0, 0x2)        },
        { SMCA_DE,       HWID_MCATYPE(0xB0, 0x3)        },
        /* HWID 0xB0 MCATYPE 0x4 is Reserved */
        { SMCA_EX,       HWID_MCATYPE(0xB0, 0x5)        },
        { SMCA_FP,       HWID_MCATYPE(0xB0, 0x6)        },
        { SMCA_L3_CACHE, HWID_MCATYPE(0xB0, 0x7)        },

        /* Data Fabric MCA types */
        { SMCA_CS,       HWID_MCATYPE(0x2E, 0x0)        },
        { SMCA_PIE,      HWID_MCATYPE(0x2E, 0x1)        },
        { SMCA_CS_V2,    HWID_MCATYPE(0x2E, 0x2)        },

        /* Unified Memory Controller MCA type */
        { SMCA_UMC,      HWID_MCATYPE(0x96, 0x0)        },
        { SMCA_UMC_V2,   HWID_MCATYPE(0x96, 0x1)        },

        /* Parameter Block MCA type */
        { SMCA_PB,       HWID_MCATYPE(0x05, 0x0)        },

        /* Platform Security Processor MCA type */
        { SMCA_PSP,      HWID_MCATYPE(0xFF, 0x0)        },
        { SMCA_PSP_V2,   HWID_MCATYPE(0xFF, 0x1)        },

        /* System Management Unit MCA type */
        { SMCA_SMU,      HWID_MCATYPE(0x01, 0x0)        },
        { SMCA_SMU_V2,   HWID_MCATYPE(0x01, 0x1)        },

        /* Microprocessor 5 Unit MCA type */
        { SMCA_MP5,      HWID_MCATYPE(0x01, 0x2)        },

        /* MPDMA MCA type */
        { SMCA_MPDMA,    HWID_MCATYPE(0x01, 0x3)        },

        /* Northbridge IO Unit MCA type */
        { SMCA_NBIO,     HWID_MCATYPE(0x18, 0x0)        },

        /* PCI Express Unit MCA type */
        { SMCA_PCIE,     HWID_MCATYPE(0x46, 0x0)        },
        { SMCA_PCIE_V2,  HWID_MCATYPE(0x46, 0x1)        },

        { SMCA_XGMI_PCS, HWID_MCATYPE(0x50, 0x0)        },
        { SMCA_NBIF,     HWID_MCATYPE(0x6C, 0x0)        },
        { SMCA_SHUB,     HWID_MCATYPE(0x80, 0x0)        },
        { SMCA_SATA,     HWID_MCATYPE(0xA8, 0x0)        },
        { SMCA_USB,      HWID_MCATYPE(0xAA, 0x0)        },
        { SMCA_GMI_PCS,  HWID_MCATYPE(0x241, 0x0)       },
        { SMCA_XGMI_PHY, HWID_MCATYPE(0x259, 0x0)       },
        { SMCA_WAFL_PHY, HWID_MCATYPE(0x267, 0x0)       },
        { SMCA_GMI_PHY,  HWID_MCATYPE(0x269, 0x0)       },
};

/*
 * In SMCA enabled processors, we can have multiple banks for a given IP type.
 * So to define a unique name for each bank, we use a temp c-string to append
 * the MCA_IPID[InstanceId] to type's name in get_name().
 *
 * InstanceId is 32 bits which is 8 characters. Make sure MAX_MCATYPE_NAME_LEN
 * is greater than 8 plus 1 (for underscore) plus length of longest type name.
 */
#define MAX_MCATYPE_NAME_LEN    30
static char buf_mcatype[MAX_MCATYPE_NAME_LEN];

static DEFINE_PER_CPU(struct threshold_bank **, threshold_banks);

/*
 * A list of the banks enabled on each logical CPU. Controls which respective
 * descriptors to initialize later in mce_threshold_create_device().
 */
static DEFINE_PER_CPU(unsigned int, bank_map);

/* Map of banks that have more than MCA_MISC0 available. */
static DEFINE_PER_CPU(u32, smca_misc_banks_map);

static void amd_threshold_interrupt(void);
static void amd_deferred_error_interrupt(void);

static void default_deferred_error_interrupt(void)
{
        pr_err("Unexpected deferred interrupt at vector %x\n", DEFERRED_ERROR_VECTOR);
}
void (*deferred_error_int_vector)(void) = default_deferred_error_interrupt;

static void smca_set_misc_banks_map(unsigned int bank, unsigned int cpu)
{
        u32 low, high;

        /*
         * For SMCA enabled processors, BLKPTR field of the first MISC register
         * (MCx_MISC0) indicates presence of additional MISC regs set (MISC1-4).
         */
        if (rdmsr_safe(MSR_AMD64_SMCA_MCx_CONFIG(bank), &low, &high))
                return;

        if (!(low & MCI_CONFIG_MCAX))
                return;

        if (rdmsr_safe(MSR_AMD64_SMCA_MCx_MISC(bank), &low, &high))
                return;

        if (low & MASK_BLKPTR_LO)
                per_cpu(smca_misc_banks_map, cpu) |= BIT(bank);

}

static void smca_configure(unsigned int bank, unsigned int cpu)
{
        u8 *bank_counts = this_cpu_ptr(smca_bank_counts);
        const struct smca_hwid *s_hwid;
        unsigned int i, hwid_mcatype;
        u32 high, low;
        u32 smca_config = MSR_AMD64_SMCA_MCx_CONFIG(bank);

        /* Set appropriate bits in MCA_CONFIG */
        if (!rdmsr_safe(smca_config, &low, &high)) {
                /*
                 * OS is required to set the MCAX bit to acknowledge that it is
                 * now using the new MSR ranges and new registers under each
                 * bank. It also means that the OS will configure deferred
                 * errors in the new MCx_CONFIG register. If the bit is not set,
                 * uncorrectable errors will cause a system panic.
                 *
                 * MCA_CONFIG[MCAX] is bit 32 (0 in the high portion of the MSR.)
                 */
                high |= BIT(0);

                /*
                 * SMCA sets the Deferred Error Interrupt type per bank.
                 *
                 * MCA_CONFIG[DeferredIntTypeSupported] is bit 5, and tells us
                 * if the DeferredIntType bit field is available.
                 *
                 * MCA_CONFIG[DeferredIntType] is bits [38:37] ([6:5] in the
                 * high portion of the MSR). OS should set this to 0x1 to enable
                 * APIC based interrupt. First, check that no interrupt has been
                 * set.
                 */
                if ((low & BIT(5)) && !((high >> 5) & 0x3))
                        high |= BIT(5);

                wrmsr(smca_config, low, high);
        }

        smca_set_misc_banks_map(bank, cpu);

        if (rdmsr_safe(MSR_AMD64_SMCA_MCx_IPID(bank), &low, &high)) {
                pr_warn("Failed to read MCA_IPID for bank %d\n", bank);
                return;
        }

        hwid_mcatype = HWID_MCATYPE(high & MCI_IPID_HWID,
                                    (high & MCI_IPID_MCATYPE) >> 16);

        for (i = 0; i < ARRAY_SIZE(smca_hwid_mcatypes); i++) {
                s_hwid = &smca_hwid_mcatypes[i];

                if (hwid_mcatype == s_hwid->hwid_mcatype) {
                        this_cpu_ptr(smca_banks)[bank].hwid = s_hwid;
                        this_cpu_ptr(smca_banks)[bank].id = low;
                        this_cpu_ptr(smca_banks)[bank].sysfs_id = bank_counts[s_hwid->bank_type]++;
                        break;
                }
        }
}

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

static inline bool is_shared_bank(int bank)
{
        /*
         * Scalable MCA provides for only one core to have access to the MSRs of
         * a shared bank.
         */
        if (mce_flags.smca)
                return false;

        /* Bank 4 is for northbridge reporting and is thus shared */
        return (bank == 4);
}

static const char *bank4_names(const struct threshold_block *b)
{
        switch (b->address) {
        /* MSR4_MISC0 */
        case 0x00000413:
                return "dram";

        case 0xc0000408:
                return "ht_links";

        case 0xc0000409:
                return "l3_cache";

        default:
                WARN(1, "Funny MSR: 0x%08x\n", b->address);
                return "";
        }
};


static bool lvt_interrupt_supported(unsigned int bank, u32 msr_high_bits)
{
        /*
         * bank 4 supports APIC LVT interrupts implicitly since forever.
         */
        if (bank == 4)
                return true;

        /*
         * IntP: interrupt present; if this bit is set, the thresholding
         * bank can generate APIC LVT interrupts
         */
        return msr_high_bits & BIT(28);
}

static int lvt_off_valid(struct threshold_block *b, int apic, u32 lo, u32 hi)
{
        int msr = (hi & MASK_LVTOFF_HI) >> 20;

        if (apic < 0) {
                pr_err(FW_BUG "cpu %d, failed to setup threshold interrupt "
                       "for bank %d, block %d (MSR%08X=0x%x%08x)\n", b->cpu,
                       b->bank, b->block, b->address, hi, lo);
                return 0;
        }

        if (apic != msr) {
                /*
                 * On SMCA CPUs, LVT offset is programmed at a different MSR, and
                 * the BIOS provides the value. The original field where LVT offset
                 * was set is reserved. Return early here:
                 */
                if (mce_flags.smca)
                        return 0;

                pr_err(FW_BUG "cpu %d, invalid threshold interrupt offset %d "
                       "for bank %d, block %d (MSR%08X=0x%x%08x)\n",
                       b->cpu, apic, b->bank, b->block, b->address, hi, lo);
                return 0;
        }

        return 1;
};

/* Reprogram MCx_MISC MSR behind this threshold bank. */
static void threshold_restart_bank(void *_tr)
{
        struct thresh_restart *tr = _tr;
        u32 hi, lo;

        /* sysfs write might race against an offline operation */
        if (this_cpu_read(threshold_banks))
                return;

        rdmsr(tr->b->address, lo, hi);

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

        if (tr->reset) {                /* reset err count and overflow bit */
                hi =
                    (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 = (hi & THRESHOLD_MAX) +
                    (tr->old_limit - tr->b->threshold_limit);

                hi = (hi & ~MASK_ERR_COUNT_HI) |
                    (new_count & THRESHOLD_MAX);
        }

        /* clear IntType */
        hi &= ~MASK_INT_TYPE_HI;

        if (!tr->b->interrupt_capable)
                goto done;

        if (tr->set_lvt_off) {
                if (lvt_off_valid(tr->b, tr->lvt_off, lo, hi)) {
                        /* set new lvt offset */
                        hi &= ~MASK_LVTOFF_HI;
                        hi |= tr->lvt_off << 20;
                }
        }

        if (tr->b->interrupt_enable)
                hi |= INT_TYPE_APIC;

 done:

        hi |= MASK_COUNT_EN_HI;
        wrmsr(tr->b->address, lo, hi);
}

static void mce_threshold_block_init(struct threshold_block *b, int offset)
{
        struct thresh_restart tr = {
                .b                      = b,
                .set_lvt_off            = 1,
                .lvt_off                = offset,
        };

        b->threshold_limit              = THRESHOLD_MAX;
        threshold_restart_bank(&tr);
};

static int setup_APIC_mce_threshold(int reserved, int new)
{
        if (reserved < 0 && !setup_APIC_eilvt(new, THRESHOLD_APIC_VECTOR,
                                              APIC_EILVT_MSG_FIX, 0))
                return new;

        return reserved;
}

static int setup_APIC_deferred_error(int reserved, int new)
{
        if (reserved < 0 && !setup_APIC_eilvt(new, DEFERRED_ERROR_VECTOR,
                                              APIC_EILVT_MSG_FIX, 0))
                return new;

        return reserved;
}

static void deferred_error_interrupt_enable(struct cpuinfo_x86 *c)
{
        u32 low = 0, high = 0;
        int def_offset = -1, def_new;

        if (rdmsr_safe(MSR_CU_DEF_ERR, &low, &high))
                return;

        def_new = (low & MASK_DEF_LVTOFF) >> 4;
        if (!(low & MASK_DEF_LVTOFF)) {
                pr_err(FW_BUG "Your BIOS is not setting up LVT offset 0x2 for deferred error IRQs correctly.\n");
                def_new = DEF_LVT_OFF;
                low = (low & ~MASK_DEF_LVTOFF) | (DEF_LVT_OFF << 4);
        }

        def_offset = setup_APIC_deferred_error(def_offset, def_new);
        if ((def_offset == def_new) &&
            (deferred_error_int_vector != amd_deferred_error_interrupt))
                deferred_error_int_vector = amd_deferred_error_interrupt;

        if (!mce_flags.smca)
                low = (low & ~MASK_DEF_INT_TYPE) | DEF_INT_TYPE_APIC;

        wrmsr(MSR_CU_DEF_ERR, low, high);
}

static u32 smca_get_block_address(unsigned int bank, unsigned int block,
                                  unsigned int cpu)
{
        if (!block)
                return MSR_AMD64_SMCA_MCx_MISC(bank);

        if (!(per_cpu(smca_misc_banks_map, cpu) & BIT(bank)))
                return 0;

        return MSR_AMD64_SMCA_MCx_MISCy(bank, block - 1);
}

static u32 get_block_address(u32 current_addr, u32 low, u32 high,
                             unsigned int bank, unsigned int block,
                             unsigned int cpu)
{
        u32 addr = 0, offset = 0;

        if ((bank >= per_cpu(mce_num_banks, cpu)) || (block >= NR_BLOCKS))
                return addr;

        if (mce_flags.smca)
                return smca_get_block_address(bank, block, cpu);

        /* Fall back to method we used for older processors: */
        switch (block) {
        case 0:
                addr = msr_ops.misc(bank);
                break;
        case 1:
                offset = ((low & MASK_BLKPTR_LO) >> 21);
                if (offset)
                        addr = MCG_XBLK_ADDR + offset;
                break;
        default:
                addr = ++current_addr;
        }
        return addr;
}

static int
prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr,
                        int offset, u32 misc_high)
{
        unsigned int cpu = smp_processor_id();
        u32 smca_low, smca_high;
        struct threshold_block b;
        int new;

        if (!block)
                per_cpu(bank_map, cpu) |= (1 << bank);

        memset(&b, 0, sizeof(b));
        b.cpu                   = cpu;
        b.bank                  = bank;
        b.block                 = block;
        b.address               = addr;
        b.interrupt_capable     = lvt_interrupt_supported(bank, misc_high);

        if (!b.interrupt_capable)
                goto done;

        b.interrupt_enable = 1;

        if (!mce_flags.smca) {
                new = (misc_high & MASK_LVTOFF_HI) >> 20;
                goto set_offset;
        }

        /* Gather LVT offset for thresholding: */
        if (rdmsr_safe(MSR_CU_DEF_ERR, &smca_low, &smca_high))
                goto out;

        new = (smca_low & SMCA_THR_LVT_OFF) >> 12;

set_offset:
        offset = setup_APIC_mce_threshold(offset, new);
        if (offset == new)
                thresholding_irq_en = true;

done:
        mce_threshold_block_init(&b, offset);

out:
        return offset;
}

bool amd_filter_mce(struct mce *m)
{
        enum smca_bank_types bank_type = smca_get_bank_type(m->extcpu, m->bank);
        struct cpuinfo_x86 *c = &boot_cpu_data;

        /* See Family 17h Models 10h-2Fh Erratum #1114. */
        if (c->x86 == 0x17 &&
            c->x86_model >= 0x10 && c->x86_model <= 0x2F &&
            bank_type == SMCA_IF && XEC(m->status, 0x3f) == 10)
                return true;

        /* NB GART TLB error reporting is disabled by default. */
        if (c->x86 < 0x17) {
                if (m->bank == 4 && XEC(m->status, 0x1f) == 0x5)
                        return true;
        }

        return false;
}

/*
 * Turn off thresholding banks for the following conditions:
 * - MC4_MISC thresholding is not supported on Family 0x15.
 * - Prevent possible spurious interrupts from the IF bank on Family 0x17
 *   Models 0x10-0x2F due to Erratum #1114.
 */
static void disable_err_thresholding(struct cpuinfo_x86 *c, unsigned int bank)
{
        int i, num_msrs;
        u64 hwcr;
        bool need_toggle;
        u32 msrs[NR_BLOCKS];

        if (c->x86 == 0x15 && bank == 4) {
                msrs[0] = 0x00000413; /* MC4_MISC0 */
                msrs[1] = 0xc0000408; /* MC4_MISC1 */
                num_msrs = 2;
        } else if (c->x86 == 0x17 &&
                   (c->x86_model >= 0x10 && c->x86_model <= 0x2F)) {

                if (smca_get_bank_type(smp_processor_id(), bank) != SMCA_IF)
                        return;

                msrs[0] = MSR_AMD64_SMCA_MCx_MISC(bank);
                num_msrs = 1;
        } else {
                return;
        }

        rdmsrl(MSR_K7_HWCR, hwcr);

        /* McStatusWrEn has to be set */
        need_toggle = !(hwcr & BIT(18));
        if (need_toggle)
                wrmsrl(MSR_K7_HWCR, hwcr | BIT(18));

        /* Clear CntP bit safely */
        for (i = 0; i < num_msrs; i++)
                msr_clear_bit(msrs[i], 62);

        /* restore old settings */
        if (need_toggle)
                wrmsrl(MSR_K7_HWCR, hwcr);
}

/* cpu init entry point, called from mce.c with preempt off */
void mce_amd_feature_init(struct cpuinfo_x86 *c)
{
        unsigned int bank, block, cpu = smp_processor_id();
        u32 low = 0, high = 0, address = 0;
        int offset = -1;


        for (bank = 0; bank < this_cpu_read(mce_num_banks); ++bank) {
                if (mce_flags.smca)
                        smca_configure(bank, cpu);

                disable_err_thresholding(c, bank);

                for (block = 0; block < NR_BLOCKS; ++block) {
                        address = get_block_address(address, low, high, bank, block, cpu);
                        if (!address)
                                break;

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

                        if (!(high & MASK_VALID_HI))
                                continue;

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

                        offset = prepare_threshold_block(bank, block, address, offset, high);
                }
        }

        if (mce_flags.succor)
                deferred_error_interrupt_enable(c);
}

int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr)
{
        u64 dram_base_addr, dram_limit_addr, dram_hole_base;
        /* We start from the normalized address */
        u64 ret_addr = norm_addr;

        u32 tmp;

        u8 die_id_shift, die_id_mask, socket_id_shift, socket_id_mask;
        u8 intlv_num_dies, intlv_num_chan, intlv_num_sockets;
        u8 intlv_addr_sel, intlv_addr_bit;
        u8 num_intlv_bits, hashed_bit;
        u8 lgcy_mmio_hole_en, base = 0;
        u8 cs_mask, cs_id = 0;
        bool hash_enabled = false;

        /* Read D18F0x1B4 (DramOffset), check if base 1 is used. */
        if (amd_df_indirect_read(nid, 0, 0x1B4, umc, &tmp))
                goto out_err;

        /* Remove HiAddrOffset from normalized address, if enabled: */
        if (tmp & BIT(0)) {
                u64 hi_addr_offset = (tmp & GENMASK_ULL(31, 20)) << 8;

                if (norm_addr >= hi_addr_offset) {
                        ret_addr -= hi_addr_offset;
                        base = 1;
                }
        }

        /* Read D18F0x110 (DramBaseAddress). */
        if (amd_df_indirect_read(nid, 0, 0x110 + (8 * base), umc, &tmp))
                goto out_err;

        /* Check if address range is valid. */
        if (!(tmp & BIT(0))) {
                pr_err("%s: Invalid DramBaseAddress range: 0x%x.\n",
                        __func__, tmp);
                goto out_err;
        }

        lgcy_mmio_hole_en = tmp & BIT(1);
        intlv_num_chan    = (tmp >> 4) & 0xF;
        intlv_addr_sel    = (tmp >> 8) & 0x7;
        dram_base_addr    = (tmp & GENMASK_ULL(31, 12)) << 16;

        /* {0, 1, 2, 3} map to address bits {8, 9, 10, 11} respectively */
        if (intlv_addr_sel > 3) {
                pr_err("%s: Invalid interleave address select %d.\n",
                        __func__, intlv_addr_sel);
                goto out_err;
        }

        /* Read D18F0x114 (DramLimitAddress). */
        if (amd_df_indirect_read(nid, 0, 0x114 + (8 * base), umc, &tmp))
                goto out_err;

        intlv_num_sockets = (tmp >> 8) & 0x1;
        intlv_num_dies    = (tmp >> 10) & 0x3;
        dram_limit_addr   = ((tmp & GENMASK_ULL(31, 12)) << 16) | GENMASK_ULL(27, 0);

        intlv_addr_bit = intlv_addr_sel + 8;

        /* Re-use intlv_num_chan by setting it equal to log2(#channels) */
        switch (intlv_num_chan) {
        case 0: intlv_num_chan = 0; break;
        case 1: intlv_num_chan = 1; break;
        case 3: intlv_num_chan = 2; break;
        case 5: intlv_num_chan = 3; break;
        case 7: intlv_num_chan = 4; break;

        case 8: intlv_num_chan = 1;
                hash_enabled = true;
                break;
        default:
                pr_err("%s: Invalid number of interleaved channels %d.\n",
                        __func__, intlv_num_chan);
                goto out_err;
        }

        num_intlv_bits = intlv_num_chan;

        if (intlv_num_dies > 2) {
                pr_err("%s: Invalid number of interleaved nodes/dies %d.\n",
                        __func__, intlv_num_dies);
                goto out_err;
        }

        num_intlv_bits += intlv_num_dies;

        /* Add a bit if sockets are interleaved. */
        num_intlv_bits += intlv_num_sockets;

        /* Assert num_intlv_bits <= 4 */
        if (num_intlv_bits > 4) {
                pr_err("%s: Invalid interleave bits %d.\n",
                        __func__, num_intlv_bits);
                goto out_err;
        }

        if (num_intlv_bits > 0) {
                u64 temp_addr_x, temp_addr_i, temp_addr_y;
                u8 die_id_bit, sock_id_bit, cs_fabric_id;

                /*
                 * Read FabricBlockInstanceInformation3_CS[BlockFabricID].
                 * This is the fabric id for this coherent slave. Use
                 * umc/channel# as instance id of the coherent slave
                 * for FICAA.
                 */
                if (amd_df_indirect_read(nid, 0, 0x50, umc, &tmp))
                        goto out_err;

                cs_fabric_id = (tmp >> 8) & 0xFF;
                die_id_bit   = 0;

                /* If interleaved over more than 1 channel: */
                if (intlv_num_chan) {
                        die_id_bit = intlv_num_chan;
                        cs_mask    = (1 << die_id_bit) - 1;
                        cs_id      = cs_fabric_id & cs_mask;
                }

                sock_id_bit = die_id_bit;

                /* Read D18F1x208 (SystemFabricIdMask). */
                if (intlv_num_dies || intlv_num_sockets)
                        if (amd_df_indirect_read(nid, 1, 0x208, umc, &tmp))
                                goto out_err;

                /* If interleaved over more than 1 die. */
                if (intlv_num_dies) {
                        sock_id_bit  = die_id_bit + intlv_num_dies;
                        die_id_shift = (tmp >> 24) & 0xF;
                        die_id_mask  = (tmp >> 8) & 0xFF;

                        cs_id |= ((cs_fabric_id & die_id_mask) >> die_id_shift) << die_id_bit;
                }

                /* If interleaved over more than 1 socket. */
                if (intlv_num_sockets) {
                        socket_id_shift = (tmp >> 28) & 0xF;
                        socket_id_mask  = (tmp >> 16) & 0xFF;

                        cs_id |= ((cs_fabric_id & socket_id_mask) >> socket_id_shift) << sock_id_bit;
                }

                /*
                 * The pre-interleaved address consists of XXXXXXIIIYYYYY
                 * where III is the ID for this CS, and XXXXXXYYYYY are the
                 * address bits from the post-interleaved address.
                 * "num_intlv_bits" has been calculated to tell us how many "I"
                 * bits there are. "intlv_addr_bit" tells us how many "Y" bits
                 * there are (where "I" starts).
                 */
                temp_addr_y = ret_addr & GENMASK_ULL(intlv_addr_bit-1, 0);
                temp_addr_i = (cs_id << intlv_addr_bit);
                temp_addr_x = (ret_addr & GENMASK_ULL(63, intlv_addr_bit)) << num_intlv_bits;
                ret_addr    = temp_addr_x | temp_addr_i | temp_addr_y;
        }

        /* Add dram base address */
        ret_addr += dram_base_addr;

        /* If legacy MMIO hole enabled */
        if (lgcy_mmio_hole_en) {
                if (amd_df_indirect_read(nid, 0, 0x104, umc, &tmp))
                        goto out_err;

                dram_hole_base = tmp & GENMASK(31, 24);
                if (ret_addr >= dram_hole_base)
                        ret_addr += (BIT_ULL(32) - dram_hole_base);
        }

        if (hash_enabled) {
                /* Save some parentheses and grab ls-bit at the end. */
                hashed_bit =    (ret_addr >> 12) ^
                                (ret_addr >> 18) ^
                                (ret_addr >> 21) ^
                                (ret_addr >> 30) ^
                                cs_id;

                hashed_bit &= BIT(0);

                if (hashed_bit != ((ret_addr >> intlv_addr_bit) & BIT(0)))
                        ret_addr ^= BIT(intlv_addr_bit);
        }

        /* Is calculated system address is above DRAM limit address? */
        if (ret_addr > dram_limit_addr)
                goto out_err;

        *sys_addr = ret_addr;
        return 0;

out_err:
        return -EINVAL;
}
EXPORT_SYMBOL_GPL(umc_normaddr_to_sysaddr);

bool amd_mce_is_memory_error(struct mce *m)
{
        /* ErrCodeExt[20:16] */
        u8 xec = (m->status >> 16) & 0x1f;

        if (mce_flags.smca)
                return smca_get_bank_type(m->extcpu, m->bank) == SMCA_UMC && xec == 0x0;

        return m->bank == 4 && xec == 0x8;
}

static void __log_error(unsigned int bank, u64 status, u64 addr, u64 misc)
{
        struct mce m;

        mce_setup(&m);

        m.status = status;
        m.misc   = misc;
        m.bank   = bank;
        m.tsc    = rdtsc();

        if (m.status & MCI_STATUS_ADDRV) {
                m.addr = addr;

                /*
                 * Extract [55:<lsb>] where lsb is the least significant
                 * *valid* bit of the address bits.
                 */
                if (mce_flags.smca) {
                        u8 lsb = (m.addr >> 56) & 0x3f;

                        m.addr &= GENMASK_ULL(55, lsb);
                }
        }

        if (mce_flags.smca) {
                rdmsrl(MSR_AMD64_SMCA_MCx_IPID(bank), m.ipid);

                if (m.status & MCI_STATUS_SYNDV)
                        rdmsrl(MSR_AMD64_SMCA_MCx_SYND(bank), m.synd);
        }

        mce_log(&m);
}

asmlinkage __visible void __irq_entry smp_deferred_error_interrupt(struct pt_regs *regs)
{
        entering_irq();
        trace_deferred_error_apic_entry(DEFERRED_ERROR_VECTOR);
        inc_irq_stat(irq_deferred_error_count);
        deferred_error_int_vector();
        trace_deferred_error_apic_exit(DEFERRED_ERROR_VECTOR);
        exiting_ack_irq();
}

/*
 * Returns true if the logged error is deferred. False, otherwise.
 */
static inline bool
_log_error_bank(unsigned int bank, u32 msr_stat, u32 msr_addr, u64 misc)
{
        u64 status, addr = 0;

        rdmsrl(msr_stat, status);
        if (!(status & MCI_STATUS_VAL))
                return false;

        if (status & MCI_STATUS_ADDRV)
                rdmsrl(msr_addr, addr);

        __log_error(bank, status, addr, misc);

        wrmsrl(msr_stat, 0);

        return status & MCI_STATUS_DEFERRED;
}

/*
 * We have three scenarios for checking for Deferred errors:
 *
 * 1) Non-SMCA systems check MCA_STATUS and log error if found.
 * 2) SMCA systems check MCA_STATUS. If error is found then log it and also
 *    clear MCA_DESTAT.
 * 3) SMCA systems check MCA_DESTAT, if error was not found in MCA_STATUS, and

 *    log it.
 */
static void log_error_deferred(unsigned int bank)
{
        bool defrd;

        defrd = _log_error_bank(bank, msr_ops.status(bank),
                                        msr_ops.addr(bank), 0);

        if (!mce_flags.smca)
                return;

        /* Clear MCA_DESTAT if we logged the deferred error from MCA_STATUS. */
        if (defrd) {
                wrmsrl(MSR_AMD64_SMCA_MCx_DESTAT(bank), 0);
                return;
        }

        /*
         * Only deferred errors are logged in MCA_DE{STAT,ADDR} so just check
         * for a valid error.
         */
        _log_error_bank(bank, MSR_AMD64_SMCA_MCx_DESTAT(bank),
                              MSR_AMD64_SMCA_MCx_DEADDR(bank), 0);
}

/* APIC interrupt handler for deferred errors */
static void amd_deferred_error_interrupt(void)
{
        unsigned int bank;

        for (bank = 0; bank < this_cpu_read(mce_num_banks); ++bank)
                log_error_deferred(bank);
}

static void log_error_thresholding(unsigned int bank, u64 misc)
{
        _log_error_bank(bank, msr_ops.status(bank), msr_ops.addr(bank), misc);
}

static void log_and_reset_block(struct threshold_block *block)
{
        struct thresh_restart tr;
        u32 low = 0, high = 0;

        if (!block)
                return;

        if (rdmsr_safe(block->address, &low, &high))
                return;

        if (!(high & MASK_OVERFLOW_HI))
                return;

        /* Log the MCE which caused the threshold event. */
        log_error_thresholding(block->bank, ((u64)high << 32) | low);

        /* Reset threshold block after logging error. */
        memset(&tr, 0, sizeof(tr));
        tr.b = block;
        threshold_restart_bank(&tr);
}

/*
 * Threshold interrupt handler will service THRESHOLD_APIC_VECTOR. The interrupt
 * goes off when error_count reaches threshold_limit.
 */
static void amd_threshold_interrupt(void)
{
        struct threshold_block *first_block = NULL, *block = NULL, *tmp = NULL;
        struct threshold_bank **bp = this_cpu_read(threshold_banks);
        unsigned int bank, cpu = smp_processor_id();

        /*
         * Validate that the threshold bank has been initialized already. The
         * handler is installed at boot time, but on a hotplug event the
         * interrupt might fire before the data has been initialized.
         */
        if (!bp)
                return;

        for (bank = 0; bank < this_cpu_read(mce_num_banks); ++bank) {
                if (!(per_cpu(bank_map, cpu) & (1 << bank)))
                        continue;

                first_block = bp[bank]->blocks;
                if (!first_block)
                        continue;

                /*
                 * The first block is also the head of the list. Check it first
                 * before iterating over the rest.
                 */
                log_and_reset_block(first_block);
                list_for_each_entry_safe(block, tmp, &first_block->miscj, miscj)
                        log_and_reset_block(block);
        }
}

/*
 * 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, "%lu\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 size)
{
        struct thresh_restart tr;
        unsigned long new;

        if (!b->interrupt_capable)
                return -EINVAL;

        if (kstrtoul(buf, 0, &new) < 0)
                return -EINVAL;

        b->interrupt_enable = !!new;

        memset(&tr, 0, sizeof(tr));
        tr.b            = b;

        if (smp_call_function_single(b->cpu, threshold_restart_bank, &tr, 1))
                return -ENODEV;

        return size;
}

static ssize_t
store_threshold_limit(struct threshold_block *b, const char *buf, size_t size)
{
        struct thresh_restart tr;
        unsigned long new;

        if (kstrtoul(buf, 0, &new) < 0)
                return -EINVAL;

        if (new > THRESHOLD_MAX)
                new = THRESHOLD_MAX;
        if (new < 1)
                new = 1;

        memset(&tr, 0, sizeof(tr));
        tr.old_limit = b->threshold_limit;
        b->threshold_limit = new;
        tr.b = b;

        if (smp_call_function_single(b->cpu, threshold_restart_bank, &tr, 1))
                return -ENODEV;

        return size;
}

static ssize_t show_error_count(struct threshold_block *b, char *buf)
{
        u32 lo, hi;

        /* CPU might be offline by now */
        if (rdmsr_on_cpu(b->cpu, b->address, &lo, &hi))
                return -ENODEV;

        return sprintf(buf, "%u\n", ((hi & THRESHOLD_MAX) -
                                     (THRESHOLD_MAX - b->threshold_limit)));
}

static struct threshold_attr error_count = {
        .attr = {.name = __stringify(error_count), .mode = 0444 },
        .show = show_error_count,
};

#define RW_ATTR(val)                                                    \
static struct threshold_attr val = {                                    \
        .attr   = {.name = __stringify(val), .mode = 0644 },            \
        .show   = show_## val,                                          \
        .store  = store_## val,                                         \
};

RW_ATTR(interrupt_enable);
RW_ATTR(threshold_limit);

static struct attribute *default_attrs[] = {
        &threshold_limit.attr,
        &error_count.attr,
        NULL,   /* possibly interrupt_enable if supported, see below */
        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 const struct sysfs_ops threshold_ops = {
        .show                   = show,
        .store                  = store,
};

static void threshold_block_release(struct kobject *kobj);

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

static const char *get_name(unsigned int cpu, unsigned int bank, struct threshold_block *b)
{
        enum smca_bank_types bank_type;

        if (!mce_flags.smca) {
                if (b && bank == 4)
                        return bank4_names(b);

                return th_names[bank];
        }

        bank_type = smca_get_bank_type(cpu, bank);
        if (bank_type >= N_SMCA_BANK_TYPES)
                return NULL;

        if (b && bank_type == SMCA_UMC) {
                if (b->block < ARRAY_SIZE(smca_umc_block_names))
                        return smca_umc_block_names[b->block];
                return NULL;
        }

        if (per_cpu(smca_bank_counts, cpu)[bank_type] == 1)
                return smca_get_name(bank_type);

        snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN,
                 "%s_%u", smca_get_name(bank_type),
                          per_cpu(smca_banks, cpu)[bank].sysfs_id);
        return buf_mcatype;
}

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

        if ((bank >= this_cpu_read(mce_num_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->interrupt_capable    = lvt_interrupt_supported(bank, high);
        b->threshold_limit      = THRESHOLD_MAX;

        if (b->interrupt_capable) {
                threshold_ktype.default_attrs[2] = &interrupt_enable.attr;
                b->interrupt_enable = 1;
        } else {
                threshold_ktype.default_attrs[2] = NULL;
        }

        INIT_LIST_HEAD(&b->miscj);

        /* This is safe as @tb is not visible yet */
        if (tb->blocks)
                list_add(&b->miscj, &tb->blocks->miscj);
        else
                tb->blocks = b;

        err = kobject_init_and_add(&b->kobj, &threshold_ktype, tb->kobj, get_name(cpu, bank, b));
        if (err)
                goto out_free;
recurse:
        address = get_block_address(address, low, high, bank, ++block, cpu);
        if (!address)
                return 0;

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

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

        return 0;

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

static int __threshold_add_blocks(struct threshold_bank *b)
{
        struct list_head *head = &b->blocks->miscj;
        struct threshold_block *pos = NULL;
        struct threshold_block *tmp = NULL;
        int err = 0;

        err = kobject_add(&b->blocks->kobj, b->kobj, b->blocks->kobj.name);
        if (err)
                return err;

        list_for_each_entry_safe(pos, tmp, head, miscj) {

                err = kobject_add(&pos->kobj, b->kobj, pos->kobj.name);
                if (err) {
                        list_for_each_entry_safe_reverse(pos, tmp, head, miscj)
                                kobject_del(&pos->kobj);

                        return err;
                }
        }
        return err;
}

static int threshold_create_bank(struct threshold_bank **bp, unsigned int cpu,
                                 unsigned int bank)
{
        struct device *dev = this_cpu_read(mce_device);
        struct amd_northbridge *nb = NULL;
        struct threshold_bank *b = NULL;
        const char *name = get_name(cpu, bank, NULL);
        int err = 0;

        if (!dev)
                return -ENODEV;

        if (is_shared_bank(bank)) {
                nb = node_to_amd_nb(topology_die_id(cpu));

                /* threshold descriptor already initialized on this node? */
                if (nb && nb->bank4) {
                        /* yes, use it */
                        b = nb->bank4;
                        err = kobject_add(b->kobj, &dev->kobj, name);
                        if (err)
                                goto out;

                        bp[bank] = b;
                        refcount_inc(&b->cpus);

                        err = __threshold_add_blocks(b);

                        goto out;
                }
        }

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

        /* Associate the bank with the per-CPU MCE device */
        b->kobj = kobject_create_and_add(name, &dev->kobj);
        if (!b->kobj) {
                err = -EINVAL;
                goto out_free;
        }

        if (is_shared_bank(bank)) {
                b->shared = 1;
                refcount_set(&b->cpus, 1);

                /* nb is already initialized, see above */
                if (nb) {
                        WARN_ON(nb->bank4);
                        nb->bank4 = b;
                }
        }

        err = allocate_threshold_blocks(cpu, b, bank, 0, msr_ops.misc(bank));
        if (err)
                goto out_kobj;

        bp[bank] = b;
        return 0;

out_kobj:
        kobject_put(b->kobj);
out_free:
        kfree(b);
out:
        return err;
}

static void threshold_block_release(struct kobject *kobj)
{
        kfree(to_block(kobj));
}

static void deallocate_threshold_blocks(struct threshold_bank *bank)
{
        struct threshold_block *pos, *tmp;

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

        kobject_put(&bank->blocks->kobj);
}

static void __threshold_remove_blocks(struct threshold_bank *b)
{
        struct threshold_block *pos = NULL;
        struct threshold_block *tmp = NULL;

        kobject_del(b->kobj);

        list_for_each_entry_safe(pos, tmp, &b->blocks->miscj, miscj)
                kobject_del(&pos->kobj);
}

static void threshold_remove_bank(struct threshold_bank *bank)
{
        struct amd_northbridge *nb;

        if (!bank->blocks)
                goto out_free;

        if (!bank->shared)
                goto out_dealloc;

        if (!refcount_dec_and_test(&bank->cpus)) {
                __threshold_remove_blocks(bank);
                return;
        } else {
                /*
                 * The last CPU on this node using the shared bank is going
                 * away, remove that bank now.
                 */
                nb = node_to_amd_nb(topology_die_id(smp_processor_id()));
                nb->bank4 = NULL;
        }

out_dealloc:
        deallocate_threshold_blocks(bank);

out_free:
        kobject_put(bank->kobj);
        kfree(bank);
}

int mce_threshold_remove_device(unsigned int cpu)
{
        struct threshold_bank **bp = this_cpu_read(threshold_banks);
        unsigned int bank, numbanks = this_cpu_read(mce_num_banks);

        if (!bp)
                return 0;

        /*
         * Clear the pointer before cleaning up, so that the interrupt won't
         * touch anything of this.
         */
        this_cpu_write(threshold_banks, NULL);

        for (bank = 0; bank < numbanks; bank++) {
                if (bp[bank]) {
                        threshold_remove_bank(bp[bank]);
                        bp[bank] = NULL;
                }
        }
        kfree(bp);
        return 0;
}

/**
 * mce_threshold_create_device - Create the per-CPU MCE threshold device
 * @cpu:        The plugged in CPU
 *
 * Create directories and files for all valid threshold banks.
 *
 * This is invoked from the CPU hotplug callback which was installed in
 * mcheck_init_device(). The invocation happens in context of the hotplug
 * thread running on @cpu.  The callback is invoked on all CPUs which are
 * online when the callback is installed or during a real hotplug event.
 */
int mce_threshold_create_device(unsigned int cpu)
{
        unsigned int numbanks, bank;
        struct threshold_bank **bp;
        int err;

        if (!mce_flags.amd_threshold)
                return 0;

        bp = this_cpu_read(threshold_banks);
        if (bp)
                return 0;

        numbanks = this_cpu_read(mce_num_banks);
        bp = kcalloc(numbanks, sizeof(*bp), GFP_KERNEL);
        if (!bp)
                return -ENOMEM;

        for (bank = 0; bank < numbanks; ++bank) {
                if (!(this_cpu_read(bank_map) & (1 << bank)))
                        continue;
                err = threshold_create_bank(bp, cpu, bank);
                if (err)
                        goto out_err;
        }
        this_cpu_write(threshold_banks, bp);

        if (thresholding_irq_en)
                mce_threshold_vector = amd_threshold_interrupt;
        return 0;
out_err:
        mce_threshold_remove_device(cpu);
        return err;
}