err_inject.c

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/*
 * err_inject.c -
 *  1.) Inject errors to a processor.
 *  2.) Query error injection capabilities.
 * This driver along with user space code can be acting as an error
 * injection tool.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Written by: Fenghua Yu <[email protected]>, Intel Corporation
 * Copyright (C) 2006, Intel Corp.  All rights reserved.
 *
 */
#include <linux/device.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/cpu.h>
#include <linux/module.h>

#define ERR_INJ_DEBUG

#define ERR_DATA_BUFFER_SIZE 3      // Three 8-byte;

#define define_one_ro(name)                         \
static DEVICE_ATTR(name, 0444, show_##name, NULL)

#define define_one_rw(name)                         \
static DEVICE_ATTR(name, 0644, show_##name, store_##name)

static u64 call_start[NR_CPUS];
static u64 phys_addr[NR_CPUS];
static u64 err_type_info[NR_CPUS];
static u64 err_struct_info[NR_CPUS];
static struct {
    u64 data1;
    u64 data2;
    u64 data3;
} __attribute__((__aligned__(16))) err_data_buffer[NR_CPUS];
static s64 status[NR_CPUS];
static u64 capabilities[NR_CPUS];
static u64 resources[NR_CPUS];

#define show(name)                          \
static ssize_t                              \
show_##name(struct device *dev, struct device_attribute *attr,  \
        char *buf)                      \
{                                   \
    u32 cpu=dev->id;                        \
    return sprintf(buf, "%lx\n", name[cpu]);            \
}

#define store(name)                         \
static ssize_t                              \
store_##name(struct device *dev, struct device_attribute *attr, \
                    const char *buf, size_t size)   \
{                                   \
    unsigned int cpu=dev->id;                   \
    name[cpu] = simple_strtoull(buf, NULL, 16);         \
    return size;                            \
}

show(call_start)

/* It's user's responsibility to call the PAL procedure on a specific
 * processor. The cpu number in driver is only used for storing data.
 */
static ssize_t
store_call_start(struct device *dev, struct device_attribute *attr,
        const char *buf, size_t size)
{
    unsigned int cpu=dev->id;
    unsigned long call_start = simple_strtoull(buf, NULL, 16);

#ifdef ERR_INJ_DEBUG
    printk(KERN_DEBUG "pal_mc_err_inject for cpu%d:\n", cpu);
    printk(KERN_DEBUG "err_type_info=%lx,\n", err_type_info[cpu]);
    printk(KERN_DEBUG "err_struct_info=%lx,\n", err_struct_info[cpu]);
    printk(KERN_DEBUG "err_data_buffer=%lx, %lx, %lx.\n",
              err_data_buffer[cpu].data1,
              err_data_buffer[cpu].data2,
              err_data_buffer[cpu].data3);
#endif
    switch (call_start) {
        case 0: /* Do nothing. */
        break;
        case 1: /* Call pal_mc_error_inject in physical mode. */
        status[cpu]=ia64_pal_mc_error_inject_phys(err_type_info[cpu],
                    err_struct_info[cpu],
                    ia64_tpa(&err_data_buffer[cpu]),
                    &capabilities[cpu],
                    &resources[cpu]);
        break;
        case 2: /* Call pal_mc_error_inject in virtual mode. */
        status[cpu]=ia64_pal_mc_error_inject_virt(err_type_info[cpu],
                    err_struct_info[cpu],
                    ia64_tpa(&err_data_buffer[cpu]),
                    &capabilities[cpu],
                    &resources[cpu]);
        break;
        default:
        status[cpu] = -EINVAL;
        break;
    }

#ifdef ERR_INJ_DEBUG
    printk(KERN_DEBUG "Returns: status=%d,\n", (int)status[cpu]);
    printk(KERN_DEBUG "capapbilities=%lx,\n", capabilities[cpu]);
    printk(KERN_DEBUG "resources=%lx\n", resources[cpu]);
#endif
    return size;
}

show(err_type_info)
store(err_type_info)

static ssize_t
show_virtual_to_phys(struct device *dev, struct device_attribute *attr,
            char *buf)
{
    unsigned int cpu=dev->id;
    return sprintf(buf, "%lx\n", phys_addr[cpu]);
}

static ssize_t
store_virtual_to_phys(struct device *dev, struct device_attribute *attr,
            const char *buf, size_t size)
{
    unsigned int cpu=dev->id;
    u64 virt_addr=simple_strtoull(buf, NULL, 16);
    int ret;

        ret = get_user_pages(current, current->mm, virt_addr,
                        1, VM_READ, 0, NULL, NULL);
    if (ret<=0) {
#ifdef ERR_INJ_DEBUG
        printk("Virtual address %lx is not existing.\n",virt_addr);
#endif
        return -EINVAL;
    }

    phys_addr[cpu] = ia64_tpa(virt_addr);
    return size;
}

show(err_struct_info)
store(err_struct_info)

static ssize_t
show_err_data_buffer(struct device *dev,
            struct device_attribute *attr, char *buf)
{
    unsigned int cpu=dev->id;

    return sprintf(buf, "%lx, %lx, %lx\n",
            err_data_buffer[cpu].data1,
            err_data_buffer[cpu].data2,
            err_data_buffer[cpu].data3);
}

static ssize_t
store_err_data_buffer(struct device *dev,
            struct device_attribute *attr,
            const char *buf, size_t size)
{
    unsigned int cpu=dev->id;
    int ret;

#ifdef ERR_INJ_DEBUG
    printk("write err_data_buffer=[%lx,%lx,%lx] on cpu%d\n",
         err_data_buffer[cpu].data1,
         err_data_buffer[cpu].data2,
         err_data_buffer[cpu].data3,
         cpu);
#endif
    ret=sscanf(buf, "%lx, %lx, %lx",
            &err_data_buffer[cpu].data1,
            &err_data_buffer[cpu].data2,
            &err_data_buffer[cpu].data3);
    if (ret!=ERR_DATA_BUFFER_SIZE)
        return -EINVAL;

    return size;
}

show(status)
show(capabilities)
show(resources)

define_one_rw(call_start);
define_one_rw(err_type_info);
define_one_rw(err_struct_info);
define_one_rw(err_data_buffer);
define_one_rw(virtual_to_phys);
define_one_ro(status);
define_one_ro(capabilities);
define_one_ro(resources);

static struct attribute *default_attrs[] = {
    &dev_attr_call_start.attr,
    &dev_attr_virtual_to_phys.attr,
    &dev_attr_err_type_info.attr,
    &dev_attr_err_struct_info.attr,
    &dev_attr_err_data_buffer.attr,
    &dev_attr_status.attr,
    &dev_attr_capabilities.attr,
    &dev_attr_resources.attr,
    NULL
};

static struct attribute_group err_inject_attr_group = {
    .attrs = default_attrs,
    .name = "err_inject"
};
/* Add/Remove err_inject interface for CPU device */
static int __cpuinit err_inject_add_dev(struct device * sys_dev)
{
    return sysfs_create_group(&sys_dev->kobj, &err_inject_attr_group);
}

static int __cpuinit err_inject_remove_dev(struct device * sys_dev)
{
    sysfs_remove_group(&sys_dev->kobj, &err_inject_attr_group);
    return 0;
}
static int __cpuinit err_inject_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:
        err_inject_add_dev(sys_dev);
        break;
    case CPU_DEAD:
    case CPU_DEAD_FROZEN:
        err_inject_remove_dev(sys_dev);
        break;
    }

    return NOTIFY_OK;
}

static struct notifier_block __cpuinitdata err_inject_cpu_notifier =
{
    .notifier_call = err_inject_cpu_callback,
};

static int __init
err_inject_init(void)
{
    int i;

#ifdef ERR_INJ_DEBUG
    printk(KERN_INFO "Enter error injection driver.\n");
#endif
    for_each_online_cpu(i) {
        err_inject_cpu_callback(&err_inject_cpu_notifier, CPU_ONLINE,
                (void *)(long)i);
    }

    register_hotcpu_notifier(&err_inject_cpu_notifier);

    return 0;
}

static void __exit
err_inject_exit(void)
{
    int i;
    struct device *sys_dev;

#ifdef ERR_INJ_DEBUG
    printk(KERN_INFO "Exit error injection driver.\n");
#endif
    for_each_online_cpu(i) {
        sys_dev = get_cpu_device(i);
        sysfs_remove_group(&sys_dev->kobj, &err_inject_attr_group);
    }
    unregister_hotcpu_notifier(&err_inject_cpu_notifier);
}

module_init(err_inject_init);
module_exit(err_inject_exit);

MODULE_AUTHOR("Fenghua Yu <[email protected]>");
MODULE_DESCRIPTION("MC error injection kernel sysfs interface");
MODULE_LICENSE("GPL");