iss4xx.c

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/*
 * PPC476 board specific routines
 *
 * Copyright 2010 Torez Smith, IBM Corporation.
 *
 * Based on earlier code:
 *    Matt Porter <[email protected]>
 *    Copyright 2002-2005 MontaVista Software Inc.
 *
 *    Eugene Surovegin <[email protected]> or <[email protected]>
 *    Copyright (c) 2003-2005 Zultys Technologies
 *
 *    Rewritten and ported to the merged powerpc tree:
 *    Copyright 2007 David Gibson <[email protected]>, 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.
 */

#include <linux/init.h>
#include <linux/of_platform.h>
#include <linux/rtc.h>

#include <asm/machdep.h>
#include <asm/prom.h>
#include <asm/udbg.h>
#include <asm/time.h>
#include <asm/uic.h>
#include <asm/ppc4xx.h>
#include <asm/mpic.h>
#include <asm/mmu.h>

static __initdata struct of_device_id iss4xx_of_bus[] = {
    { .compatible = "ibm,plb4", },
    { .compatible = "ibm,plb6", },
    { .compatible = "ibm,opb", },
    { .compatible = "ibm,ebc", },
    {},
};

static int __init iss4xx_device_probe(void)
{
    of_platform_bus_probe(NULL, iss4xx_of_bus, NULL);
    of_instantiate_rtc();

    return 0;
}
machine_device_initcall(iss4xx, iss4xx_device_probe);

/* We can have either UICs or MPICs */
static void __init iss4xx_init_irq(void)
{
    struct device_node *np;

    /* Find top level interrupt controller */
    for_each_node_with_property(np, "interrupt-controller") {
        if (of_get_property(np, "interrupts", NULL) == NULL)
            break;
    }
    if (np == NULL)
        panic("Can't find top level interrupt controller");

    /* Check type and do appropriate initialization */
    if (of_device_is_compatible(np, "ibm,uic")) {
        uic_init_tree();
        ppc_md.get_irq = uic_get_irq;
#ifdef CONFIG_MPIC
    } else if (of_device_is_compatible(np, "chrp,open-pic")) {
        /* The MPIC driver will get everything it needs from the
         * device-tree, just pass 0 to all arguments
         */
        struct mpic *mpic = mpic_alloc(np, 0, MPIC_NO_RESET, 0, 0, " MPIC     ");
        BUG_ON(mpic == NULL);
        mpic_init(mpic);
        ppc_md.get_irq = mpic_get_irq;
#endif
    } else
        panic("Unrecognized top level interrupt controller");
}

#ifdef CONFIG_SMP
static void __cpuinit smp_iss4xx_setup_cpu(int cpu)
{
    mpic_setup_this_cpu();
}

static int __cpuinit smp_iss4xx_kick_cpu(int cpu)
{
    struct device_node *cpunode = of_get_cpu_node(cpu, NULL);
    const u64 *spin_table_addr_prop;
    u32 *spin_table;
    extern void start_secondary_47x(void);

    BUG_ON(cpunode == NULL);

    /* Assume spin table. We could test for the enable-method in
     * the device-tree but currently there's little point as it's
     * our only supported method
     */
    spin_table_addr_prop = of_get_property(cpunode, "cpu-release-addr",
                           NULL);
    if (spin_table_addr_prop == NULL) {
        pr_err("CPU%d: Can't start, missing cpu-release-addr !\n", cpu);
        return -ENOENT;
    }

    /* Assume it's mapped as part of the linear mapping. This is a bit
     * fishy but will work fine for now
     */
    spin_table = (u32 *)__va(*spin_table_addr_prop);
    pr_debug("CPU%d: Spin table mapped at %p\n", cpu, spin_table);

    spin_table[3] = cpu;
    smp_wmb();
    spin_table[1] = __pa(start_secondary_47x);
    mb();

    return 0;
}

static struct smp_ops_t iss_smp_ops = {
    .probe      = smp_mpic_probe,
    .message_pass   = smp_mpic_message_pass,
    .setup_cpu  = smp_iss4xx_setup_cpu,
    .kick_cpu   = smp_iss4xx_kick_cpu,
    .give_timebase  = smp_generic_give_timebase,
    .take_timebase  = smp_generic_take_timebase,
};

static void __init iss4xx_smp_init(void)
{
    if (mmu_has_feature(MMU_FTR_TYPE_47x))
        smp_ops = &iss_smp_ops;
}

#else /* CONFIG_SMP */
static void __init iss4xx_smp_init(void) { }
#endif /* CONFIG_SMP */

static void __init iss4xx_setup_arch(void)
{
    iss4xx_smp_init();
}

/*
 * Called very early, MMU is off, device-tree isn't unflattened
 */
static int __init iss4xx_probe(void)
{
    unsigned long root = of_get_flat_dt_root();

    if (!of_flat_dt_is_compatible(root, "ibm,iss-4xx"))
        return 0;

    return 1;
}

define_machine(iss4xx) {
    .name           = "ISS-4xx",
    .probe          = iss4xx_probe,
    .progress       = udbg_progress,
    .init_IRQ       = iss4xx_init_irq,
    .setup_arch     = iss4xx_setup_arch,
    .restart        = ppc4xx_reset_system,
    .calibrate_decr     = generic_calibrate_decr,
};