ras.c

Go to the documentation of this file.

/*
 * Copyright 2006-2008, IBM Corporation.
 *
 * 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.
 */

#undef DEBUG

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/reboot.h>
#include <linux/kexec.h>
#include <linux/crash_dump.h>

#include <asm/kexec.h>
#include <asm/reg.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/rtas.h>
#include <asm/cell-regs.h>

#include "ras.h"


static void dump_fir(int cpu)
{
    struct cbe_pmd_regs __iomem *pregs = cbe_get_cpu_pmd_regs(cpu);
    struct cbe_iic_regs __iomem *iregs = cbe_get_cpu_iic_regs(cpu);

    if (pregs == NULL)
        return;

    /* Todo: do some nicer parsing of bits and based on them go down
     * to other sub-units FIRs and not only IIC
     */
    printk(KERN_ERR "Global Checkstop FIR    : 0x%016llx\n",
           in_be64(&pregs->checkstop_fir));
    printk(KERN_ERR "Global Recoverable FIR  : 0x%016llx\n",
           in_be64(&pregs->checkstop_fir));
    printk(KERN_ERR "Global MachineCheck FIR : 0x%016llx\n",
           in_be64(&pregs->spec_att_mchk_fir));

    if (iregs == NULL)
        return;
    printk(KERN_ERR "IOC FIR                 : 0x%016llx\n",
           in_be64(&iregs->ioc_fir));

}

void cbe_system_error_exception(struct pt_regs *regs)
{
    int cpu = smp_processor_id();

    printk(KERN_ERR "System Error Interrupt on CPU %d !\n", cpu);
    dump_fir(cpu);
    dump_stack();
}

void cbe_maintenance_exception(struct pt_regs *regs)
{
    int cpu = smp_processor_id();

    /*
     * Nothing implemented for the maintenance interrupt at this point
     */

    printk(KERN_ERR "Unhandled Maintenance interrupt on CPU %d !\n", cpu);
    dump_stack();
}

void cbe_thermal_exception(struct pt_regs *regs)
{
    int cpu = smp_processor_id();

    /*
     * Nothing implemented for the thermal interrupt at this point
     */

    printk(KERN_ERR "Unhandled Thermal interrupt on CPU %d !\n", cpu);
    dump_stack();
}

static int cbe_machine_check_handler(struct pt_regs *regs)
{
    int cpu = smp_processor_id();

    printk(KERN_ERR "Machine Check Interrupt on CPU %d !\n", cpu);
    dump_fir(cpu);

    /* No recovery from this code now, lets continue */
    return 0;
}

struct ptcal_area {
    struct list_head list;
    int nid;
    int order;
    struct page *pages;
};

static LIST_HEAD(ptcal_list);

static int ptcal_start_tok, ptcal_stop_tok;

static int __init cbe_ptcal_enable_on_node(int nid, int order)
{
    struct ptcal_area *area;
    int ret = -ENOMEM;
    unsigned long addr;

    if (is_kdump_kernel())
        rtas_call(ptcal_stop_tok, 1, 1, NULL, nid);

    area = kmalloc(sizeof(*area), GFP_KERNEL);
    if (!area)
        goto out_err;

    area->nid = nid;
    area->order = order;
    area->pages = alloc_pages_exact_node(area->nid, GFP_KERNEL|GFP_THISNODE,
                        area->order);

    if (!area->pages) {
        printk(KERN_WARNING "%s: no page on node %d\n",
            __func__, area->nid);
        goto out_free_area;
    }

    /*
     * We move the ptcal area to the middle of the allocated
     * page, in order to avoid prefetches in memcpy and similar
     * functions stepping on it.
     */
    addr = __pa(page_address(area->pages)) + (PAGE_SIZE >> 1);
    printk(KERN_DEBUG "%s: enabling PTCAL on node %d address=0x%016lx\n",
            __func__, area->nid, addr);

    ret = -EIO;
    if (rtas_call(ptcal_start_tok, 3, 1, NULL, area->nid,
                (unsigned int)(addr >> 32),
                (unsigned int)(addr & 0xffffffff))) {
        printk(KERN_ERR "%s: error enabling PTCAL on node %d!\n",
                __func__, nid);
        goto out_free_pages;
    }

    list_add(&area->list, &ptcal_list);

    return 0;

out_free_pages:
    __free_pages(area->pages, area->order);
out_free_area:
    kfree(area);
out_err:
    return ret;
}

static int __init cbe_ptcal_enable(void)
{
    const u32 *size;
    struct device_node *np;
    int order, found_mic = 0;

    np = of_find_node_by_path("/rtas");
    if (!np)
        return -ENODEV;

    size = of_get_property(np, "ibm,cbe-ptcal-size", NULL);
    if (!size) {
        of_node_put(np);
        return -ENODEV;
    }

    pr_debug("%s: enabling PTCAL, size = 0x%x\n", __func__, *size);
    order = get_order(*size);
    of_node_put(np);

    /* support for malta device trees, with be@/mic@ nodes */
    for_each_node_by_type(np, "mic-tm") {
        cbe_ptcal_enable_on_node(of_node_to_nid(np), order);
        found_mic = 1;
    }

    if (found_mic)
        return 0;

    /* support for older device tree - use cpu nodes */
    for_each_node_by_type(np, "cpu") {
        const u32 *nid = of_get_property(np, "node-id", NULL);
        if (!nid) {
            printk(KERN_ERR "%s: node %s is missing node-id?\n",
                    __func__, np->full_name);
            continue;
        }
        cbe_ptcal_enable_on_node(*nid, order);
        found_mic = 1;
    }

    return found_mic ? 0 : -ENODEV;
}

static int cbe_ptcal_disable(void)
{
    struct ptcal_area *area, *tmp;
    int ret = 0;

    pr_debug("%s: disabling PTCAL\n", __func__);

    list_for_each_entry_safe(area, tmp, &ptcal_list, list) {
        /* disable ptcal on this node */
        if (rtas_call(ptcal_stop_tok, 1, 1, NULL, area->nid)) {
            printk(KERN_ERR "%s: error disabling PTCAL "
                    "on node %d!\n", __func__,
                    area->nid);
            ret = -EIO;
            continue;
        }

        /* ensure we can access the PTCAL area */
        memset(page_address(area->pages), 0,
                1 << (area->order + PAGE_SHIFT));

        /* clean up */
        list_del(&area->list);
        __free_pages(area->pages, area->order);
        kfree(area);
    }

    return ret;
}

static int cbe_ptcal_notify_reboot(struct notifier_block *nb,
        unsigned long code, void *data)
{
    return cbe_ptcal_disable();
}

static void cbe_ptcal_crash_shutdown(void)
{
    cbe_ptcal_disable();
}

static struct notifier_block cbe_ptcal_reboot_notifier = {
    .notifier_call = cbe_ptcal_notify_reboot
};

#ifdef CONFIG_PPC_IBM_CELL_RESETBUTTON
static int sysreset_hack;

static int __init cbe_sysreset_init(void)
{
    struct cbe_pmd_regs __iomem *regs;

    sysreset_hack = of_machine_is_compatible("IBM,CBPLUS-1.0");
    if (!sysreset_hack)
        return 0;

    regs = cbe_get_cpu_pmd_regs(0);
    if (!regs)
        return 0;

    /* Enable JTAG system-reset hack */
    out_be32(&regs->fir_mode_reg,
        in_be32(&regs->fir_mode_reg) |
        CBE_PMD_FIR_MODE_M8);

    return 0;
}
device_initcall(cbe_sysreset_init);

int cbe_sysreset_hack(void)
{
    struct cbe_pmd_regs __iomem *regs;

    /*
     * The BMC can inject user triggered system reset exceptions,
     * but cannot set the system reset reason in srr1,
     * so check an extra register here.
     */
    if (sysreset_hack && (smp_processor_id() == 0)) {
        regs = cbe_get_cpu_pmd_regs(0);
        if (!regs)
            return 0;
        if (in_be64(&regs->ras_esc_0) & 0x0000ffff) {
            out_be64(&regs->ras_esc_0, 0);
            return 0;
        }
    }
    return 1;
}
#endif /* CONFIG_PPC_IBM_CELL_RESETBUTTON */

int __init cbe_ptcal_init(void)
{
    int ret;
    ptcal_start_tok = rtas_token("ibm,cbe-start-ptcal");
    ptcal_stop_tok = rtas_token("ibm,cbe-stop-ptcal");

    if (ptcal_start_tok == RTAS_UNKNOWN_SERVICE
            || ptcal_stop_tok == RTAS_UNKNOWN_SERVICE)
        return -ENODEV;

    ret = register_reboot_notifier(&cbe_ptcal_reboot_notifier);
    if (ret)
        goto out1;

    ret = crash_shutdown_register(&cbe_ptcal_crash_shutdown);
    if (ret)
        goto out2;

    return cbe_ptcal_enable();

out2:
    unregister_reboot_notifier(&cbe_ptcal_reboot_notifier);
out1:
    printk(KERN_ERR "Can't disable PTCAL, so not enabling\n");
    return ret;
}

arch_initcall(cbe_ptcal_init);

void __init cbe_ras_init(void)
{
    unsigned long hid0;

    /*
     * Enable System Error & thermal interrupts and wakeup conditions
     */

    hid0 = mfspr(SPRN_HID0);
    hid0 |= HID0_CBE_THERM_INT_EN | HID0_CBE_THERM_WAKEUP |
        HID0_CBE_SYSERR_INT_EN | HID0_CBE_SYSERR_WAKEUP;
    mtspr(SPRN_HID0, hid0);
    mb();

    /*
     * Install machine check handler. Leave setting of precise mode to
     * what the firmware did for now
     */
    ppc_md.machine_check_exception = cbe_machine_check_handler;
    mb();

    /*
     * For now, we assume that IOC_FIR is already set to forward some
     * error conditions to the System Error handler. If that is not true
     * then it will have to be fixed up here.
     */
}