/*
 * 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.
         */
}