rtasd.c

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/*
 * Copyright (C) 2001 Anton Blanchard <[email protected]>, IBM
 *
 * 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.
 *
 * Communication to userspace based on kernel/printk.c
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <linux/spinlock.h>
#include <linux/cpu.h>
#include <linux/workqueue.h>
#include <linux/slab.h>

#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/rtas.h>
#include <asm/prom.h>
#include <asm/nvram.h>
#include <linux/atomic.h>
#include <asm/machdep.h>


static DEFINE_SPINLOCK(rtasd_log_lock);

static DECLARE_WAIT_QUEUE_HEAD(rtas_log_wait);

static char *rtas_log_buf;
static unsigned long rtas_log_start;
static unsigned long rtas_log_size;

static int surveillance_timeout = -1;

static unsigned int rtas_error_log_max;
static unsigned int rtas_error_log_buffer_max;

/* RTAS service tokens */
static unsigned int event_scan;
static unsigned int rtas_event_scan_rate;

static int full_rtas_msgs = 0;

/* Stop logging to nvram after first fatal error */
static int logging_enabled; /* Until we initialize everything,
                             * make sure we don't try logging
                             * anything */
static int error_log_cnt;

/*
 * Since we use 32 bit RTAS, the physical address of this must be below
 * 4G or else bad things happen. Allocate this in the kernel data and
 * make it big enough.
 */
static unsigned char logdata[RTAS_ERROR_LOG_MAX];

static char *rtas_type[] = {
    "Unknown", "Retry", "TCE Error", "Internal Device Failure",
    "Timeout", "Data Parity", "Address Parity", "Cache Parity",
    "Address Invalid", "ECC Uncorrected", "ECC Corrupted",
};

static char *rtas_event_type(int type)
{
    if ((type > 0) && (type < 11))
        return rtas_type[type];

    switch (type) {
        case RTAS_TYPE_EPOW:
            return "EPOW";
        case RTAS_TYPE_PLATFORM:
            return "Platform Error";
        case RTAS_TYPE_IO:
            return "I/O Event";
        case RTAS_TYPE_INFO:
            return "Platform Information Event";
        case RTAS_TYPE_DEALLOC:
            return "Resource Deallocation Event";
        case RTAS_TYPE_DUMP:
            return "Dump Notification Event";
    }

    return rtas_type[0];
}

/* To see this info, grep RTAS /var/log/messages and each entry
 * will be collected together with obvious begin/end.
 * There will be a unique identifier on the begin and end lines.
 * This will persist across reboots.
 *
 * format of error logs returned from RTAS:
 * bytes    (size)  : contents
 * --------------------------------------------------------
 * 0-7      (8) : rtas_error_log
 * 8-47     (40)    : extended info
 * 48-51    (4) : vendor id
 * 52-1023 (vendor specific) : location code and debug data
 */
static void printk_log_rtas(char *buf, int len)
{

    int i,j,n = 0;
    int perline = 16;
    char buffer[64];
    char * str = "RTAS event";

    if (full_rtas_msgs) {
        printk(RTAS_DEBUG "%d -------- %s begin --------\n",
               error_log_cnt, str);

        /*
         * Print perline bytes on each line, each line will start
         * with RTAS and a changing number, so syslogd will
         * print lines that are otherwise the same.  Separate every
         * 4 bytes with a space.
         */
        for (i = 0; i < len; i++) {
            j = i % perline;
            if (j == 0) {
                memset(buffer, 0, sizeof(buffer));
                n = sprintf(buffer, "RTAS %d:", i/perline);
            }

            if ((i % 4) == 0)
                n += sprintf(buffer+n, " ");

            n += sprintf(buffer+n, "%02x", (unsigned char)buf[i]);

            if (j == (perline-1))
                printk(KERN_DEBUG "%s\n", buffer);
        }
        if ((i % perline) != 0)
            printk(KERN_DEBUG "%s\n", buffer);

        printk(RTAS_DEBUG "%d -------- %s end ----------\n",
               error_log_cnt, str);
    } else {
        struct rtas_error_log *errlog = (struct rtas_error_log *)buf;

        printk(RTAS_DEBUG "event: %d, Type: %s, Severity: %d\n",
               error_log_cnt, rtas_event_type(errlog->type),
               errlog->severity);
    }
}

static int log_rtas_len(char * buf)
{
    int len;
    struct rtas_error_log *err;

    /* rtas fixed header */
    len = 8;
    err = (struct rtas_error_log *)buf;
    if (err->extended && err->extended_log_length) {

        /* extended header */
        len += err->extended_log_length;
    }

    if (rtas_error_log_max == 0)
        rtas_error_log_max = rtas_get_error_log_max();

    if (len > rtas_error_log_max)
        len = rtas_error_log_max;

    return len;
}

/*
 * First write to nvram, if fatal error, that is the only
 * place we log the info.  The error will be picked up
 * on the next reboot by rtasd.  If not fatal, run the
 * method for the type of error.  Currently, only RTAS
 * errors have methods implemented, but in the future
 * there might be a need to store data in nvram before a
 * call to panic().
 *
 * XXX We write to nvram periodically, to indicate error has
 * been written and sync'd, but there is a possibility
 * that if we don't shutdown correctly, a duplicate error
 * record will be created on next reboot.
 */
void pSeries_log_error(char *buf, unsigned int err_type, int fatal)
{
    unsigned long offset;
    unsigned long s;
    int len = 0;

    pr_debug("rtasd: logging event\n");
    if (buf == NULL)
        return;

    spin_lock_irqsave(&rtasd_log_lock, s);

    /* get length and increase count */
    switch (err_type & ERR_TYPE_MASK) {
    case ERR_TYPE_RTAS_LOG:
        len = log_rtas_len(buf);
        if (!(err_type & ERR_FLAG_BOOT))
            error_log_cnt++;
        break;
    case ERR_TYPE_KERNEL_PANIC:
    default:
        WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
        spin_unlock_irqrestore(&rtasd_log_lock, s);
        return;
    }

#ifdef CONFIG_PPC64
    /* Write error to NVRAM */
    if (logging_enabled && !(err_type & ERR_FLAG_BOOT))
        nvram_write_error_log(buf, len, err_type, error_log_cnt);
#endif /* CONFIG_PPC64 */

    /*
     * rtas errors can occur during boot, and we do want to capture
     * those somewhere, even if nvram isn't ready (why not?), and even
     * if rtasd isn't ready. Put them into the boot log, at least.
     */
    if ((err_type & ERR_TYPE_MASK) == ERR_TYPE_RTAS_LOG)
        printk_log_rtas(buf, len);

    /* Check to see if we need to or have stopped logging */
    if (fatal || !logging_enabled) {
        logging_enabled = 0;
        WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
        spin_unlock_irqrestore(&rtasd_log_lock, s);
        return;
    }

    /* call type specific method for error */
    switch (err_type & ERR_TYPE_MASK) {
    case ERR_TYPE_RTAS_LOG:
        offset = rtas_error_log_buffer_max *
            ((rtas_log_start+rtas_log_size) & LOG_NUMBER_MASK);

        /* First copy over sequence number */
        memcpy(&rtas_log_buf[offset], (void *) &error_log_cnt, sizeof(int));

        /* Second copy over error log data */
        offset += sizeof(int);
        memcpy(&rtas_log_buf[offset], buf, len);

        if (rtas_log_size < LOG_NUMBER)
            rtas_log_size += 1;
        else
            rtas_log_start += 1;

        WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
        spin_unlock_irqrestore(&rtasd_log_lock, s);
        wake_up_interruptible(&rtas_log_wait);
        break;
    case ERR_TYPE_KERNEL_PANIC:
    default:
        WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
        spin_unlock_irqrestore(&rtasd_log_lock, s);
        return;
    }

}

static int rtas_log_open(struct inode * inode, struct file * file)
{
    return 0;
}

static int rtas_log_release(struct inode * inode, struct file * file)
{
    return 0;
}

/* This will check if all events are logged, if they are then, we
 * know that we can safely clear the events in NVRAM.
 * Next we'll sit and wait for something else to log.
 */
static ssize_t rtas_log_read(struct file * file, char __user * buf,
             size_t count, loff_t *ppos)
{
    int error;
    char *tmp;
    unsigned long s;
    unsigned long offset;

    if (!buf || count < rtas_error_log_buffer_max)
        return -EINVAL;

    count = rtas_error_log_buffer_max;

    if (!access_ok(VERIFY_WRITE, buf, count))
        return -EFAULT;

    tmp = kmalloc(count, GFP_KERNEL);
    if (!tmp)
        return -ENOMEM;

    spin_lock_irqsave(&rtasd_log_lock, s);

    /* if it's 0, then we know we got the last one (the one in NVRAM) */
    while (rtas_log_size == 0) {
        if (file->f_flags & O_NONBLOCK) {
            spin_unlock_irqrestore(&rtasd_log_lock, s);
            error = -EAGAIN;
            goto out;
        }

        if (!logging_enabled) {
            spin_unlock_irqrestore(&rtasd_log_lock, s);
            error = -ENODATA;
            goto out;
        }
#ifdef CONFIG_PPC64
        nvram_clear_error_log();
#endif /* CONFIG_PPC64 */

        spin_unlock_irqrestore(&rtasd_log_lock, s);
        error = wait_event_interruptible(rtas_log_wait, rtas_log_size);
        if (error)
            goto out;
        spin_lock_irqsave(&rtasd_log_lock, s);
    }

    offset = rtas_error_log_buffer_max * (rtas_log_start & LOG_NUMBER_MASK);
    memcpy(tmp, &rtas_log_buf[offset], count);

    rtas_log_start += 1;
    rtas_log_size -= 1;
    spin_unlock_irqrestore(&rtasd_log_lock, s);

    error = copy_to_user(buf, tmp, count) ? -EFAULT : count;
out:
    kfree(tmp);
    return error;
}

static unsigned int rtas_log_poll(struct file *file, poll_table * wait)
{
    poll_wait(file, &rtas_log_wait, wait);
    if (rtas_log_size)
        return POLLIN | POLLRDNORM;
    return 0;
}

static const struct file_operations proc_rtas_log_operations = {
    .read =     rtas_log_read,
    .poll =     rtas_log_poll,
    .open =     rtas_log_open,
    .release =  rtas_log_release,
    .llseek =   noop_llseek,
};

static int enable_surveillance(int timeout)
{
    int error;

    error = rtas_set_indicator(SURVEILLANCE_TOKEN, 0, timeout);

    if (error == 0)
        return 0;

    if (error == -EINVAL) {
        printk(KERN_DEBUG "rtasd: surveillance not supported\n");
        return 0;
    }

    printk(KERN_ERR "rtasd: could not update surveillance\n");
    return -1;
}

static void do_event_scan(void)
{
    int error;
    do {
        memset(logdata, 0, rtas_error_log_max);
        error = rtas_call(event_scan, 4, 1, NULL,
                  RTAS_EVENT_SCAN_ALL_EVENTS, 0,
                  __pa(logdata), rtas_error_log_max);
        if (error == -1) {
            printk(KERN_ERR "event-scan failed\n");
            break;
        }

        if (error == 0)
            pSeries_log_error(logdata, ERR_TYPE_RTAS_LOG, 0);

    } while(error == 0);
}

static void rtas_event_scan(struct work_struct *w);
DECLARE_DELAYED_WORK(event_scan_work, rtas_event_scan);

/*
 * Delay should be at least one second since some machines have problems if
 * we call event-scan too quickly.
 */
static unsigned long event_scan_delay = 1*HZ;
static int first_pass = 1;

static void rtas_event_scan(struct work_struct *w)
{
    unsigned int cpu;

    do_event_scan();

    get_online_cpus();

    /* raw_ OK because just using CPU as starting point. */
    cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask);
        if (cpu >= nr_cpu_ids) {
        cpu = cpumask_first(cpu_online_mask);

        if (first_pass) {
            first_pass = 0;
            event_scan_delay = 30*HZ/rtas_event_scan_rate;

            if (surveillance_timeout != -1) {
                pr_debug("rtasd: enabling surveillance\n");
                enable_surveillance(surveillance_timeout);
                pr_debug("rtasd: surveillance enabled\n");
            }
        }
    }

    schedule_delayed_work_on(cpu, &event_scan_work,
        __round_jiffies_relative(event_scan_delay, cpu));

    put_online_cpus();
}

#ifdef CONFIG_PPC64
static void retreive_nvram_error_log(void)
{
    unsigned int err_type ;
    int rc ;

    /* See if we have any error stored in NVRAM */
    memset(logdata, 0, rtas_error_log_max);
    rc = nvram_read_error_log(logdata, rtas_error_log_max,
                              &err_type, &error_log_cnt);
    /* We can use rtas_log_buf now */
    logging_enabled = 1;
    if (!rc) {
        if (err_type != ERR_FLAG_ALREADY_LOGGED) {
            pSeries_log_error(logdata, err_type | ERR_FLAG_BOOT, 0);
        }
    }
}
#else /* CONFIG_PPC64 */
static void retreive_nvram_error_log(void)
{
}
#endif /* CONFIG_PPC64 */

static void start_event_scan(void)
{
    printk(KERN_DEBUG "RTAS daemon started\n");
    pr_debug("rtasd: will sleep for %d milliseconds\n",
         (30000 / rtas_event_scan_rate));

    /* Retrieve errors from nvram if any */
    retreive_nvram_error_log();

    schedule_delayed_work_on(cpumask_first(cpu_online_mask),
                 &event_scan_work, event_scan_delay);
}

/* Cancel the rtas event scan work */
void rtas_cancel_event_scan(void)
{
    cancel_delayed_work_sync(&event_scan_work);
}
EXPORT_SYMBOL_GPL(rtas_cancel_event_scan);

static int __init rtas_init(void)
{
    struct proc_dir_entry *entry;

    if (!machine_is(pseries) && !machine_is(chrp))
        return 0;

    /* No RTAS */
    event_scan = rtas_token("event-scan");
    if (event_scan == RTAS_UNKNOWN_SERVICE) {
        printk(KERN_INFO "rtasd: No event-scan on system\n");
        return -ENODEV;
    }

    rtas_event_scan_rate = rtas_token("rtas-event-scan-rate");
    if (rtas_event_scan_rate == RTAS_UNKNOWN_SERVICE) {
        printk(KERN_ERR "rtasd: no rtas-event-scan-rate on system\n");
        return -ENODEV;
    }

    if (!rtas_event_scan_rate) {
        /* Broken firmware: take a rate of zero to mean don't scan */
        printk(KERN_DEBUG "rtasd: scan rate is 0, not scanning\n");
        return 0;
    }

    /* Make room for the sequence number */
    rtas_error_log_max = rtas_get_error_log_max();
    rtas_error_log_buffer_max = rtas_error_log_max + sizeof(int);

    rtas_log_buf = vmalloc(rtas_error_log_buffer_max*LOG_NUMBER);
    if (!rtas_log_buf) {
        printk(KERN_ERR "rtasd: no memory\n");
        return -ENOMEM;
    }

    entry = proc_create("powerpc/rtas/error_log", S_IRUSR, NULL,
                &proc_rtas_log_operations);
    if (!entry)
        printk(KERN_ERR "Failed to create error_log proc entry\n");

    start_event_scan();

    return 0;
}
__initcall(rtas_init);

static int __init surveillance_setup(char *str)
{
    int i;

    /* We only do surveillance on pseries */
    if (!machine_is(pseries))
        return 0;

    if (get_option(&str,&i)) {
        if (i >= 0 && i <= 255)
            surveillance_timeout = i;
    }

    return 1;
}
__setup("surveillance=", surveillance_setup);

static int __init rtasmsgs_setup(char *str)
{
    if (strcmp(str, "on") == 0)
        full_rtas_msgs = 1;
    else if (strcmp(str, "off") == 0)
        full_rtas_msgs = 0;

    return 1;
}
__setup("rtasmsgs=", rtasmsgs_setup);