powerpc/smp: smp_ops->kick_cpu() should be able to fail

[mirror_ubuntu-zesty-kernel.git] / arch / powerpc / platforms / powermac / smp.c

/*
 * SMP support for power macintosh.
 *
 * We support both the old "powersurge" SMP architecture
 * and the current Core99 (G4 PowerMac) machines.
 *
 * Note that we don't support the very first rev. of
 * Apple/DayStar 2 CPUs board, the one with the funky
 * watchdog. Hopefully, none of these should be there except
 * maybe internally to Apple. I should probably still add some
 * code to detect this card though and disable SMP. --BenH.
 *
 * Support Macintosh G4 SMP by Troy Benjegerdes (hozer@drgw.net)
 * and Ben Herrenschmidt <benh@kernel.crashing.org>.
 *
 * Support for DayStar quad CPU cards
 * Copyright (C) XLR8, Inc. 1994-2000
 *
 *  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/kernel.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/hardirq.h>
#include <linux/cpu.h>
#include <linux/compiler.h>

#include <asm/ptrace.h>
#include <asm/atomic.h>
#include <asm/code-patching.h>
#include <asm/irq.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/sections.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/pmac_feature.h>
#include <asm/time.h>
#include <asm/mpic.h>
#include <asm/cacheflush.h>
#include <asm/keylargo.h>
#include <asm/pmac_low_i2c.h>
#include <asm/pmac_pfunc.h>

#include "pmac.h"

#undef DEBUG

#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif

extern void __secondary_start_pmac_0(void);
extern int pmac_pfunc_base_install(void);

static void (*pmac_tb_freeze)(int freeze);
static u64 timebase;
static int tb_req;

#ifdef CONFIG_PPC32

/*
 * Powersurge (old powermac SMP) support.
 */

/* Addresses for powersurge registers */
#define HAMMERHEAD_BASE         0xf8000000
#define HHEAD_CONFIG            0x90
#define HHEAD_SEC_INTR          0xc0

/* register for interrupting the primary processor on the powersurge */
/* N.B. this is actually the ethernet ROM! */
#define PSURGE_PRI_INTR         0xf3019000

/* register for storing the start address for the secondary processor */
/* N.B. this is the PCI config space address register for the 1st bridge */
#define PSURGE_START            0xf2800000

/* Daystar/XLR8 4-CPU card */
#define PSURGE_QUAD_REG_ADDR    0xf8800000

#define PSURGE_QUAD_IRQ_SET     0
#define PSURGE_QUAD_IRQ_CLR     1
#define PSURGE_QUAD_IRQ_PRIMARY 2
#define PSURGE_QUAD_CKSTOP_CTL  3
#define PSURGE_QUAD_PRIMARY_ARB 4
#define PSURGE_QUAD_BOARD_ID    6
#define PSURGE_QUAD_WHICH_CPU   7
#define PSURGE_QUAD_CKSTOP_RDBK 8
#define PSURGE_QUAD_RESET_CTL   11

#define PSURGE_QUAD_OUT(r, v)   (out_8(quad_base + ((r) << 4) + 4, (v)))
#define PSURGE_QUAD_IN(r)       (in_8(quad_base + ((r) << 4) + 4) & 0x0f)
#define PSURGE_QUAD_BIS(r, v)   (PSURGE_QUAD_OUT((r), PSURGE_QUAD_IN(r) | (v)))
#define PSURGE_QUAD_BIC(r, v)   (PSURGE_QUAD_OUT((r), PSURGE_QUAD_IN(r) & ~(v)))

/* virtual addresses for the above */
static volatile u8 __iomem *hhead_base;
static volatile u8 __iomem *quad_base;
static volatile u32 __iomem *psurge_pri_intr;
static volatile u8 __iomem *psurge_sec_intr;
static volatile u32 __iomem *psurge_start;

/* values for psurge_type */
#define PSURGE_NONE             -1
#define PSURGE_DUAL             0
#define PSURGE_QUAD_OKEE        1
#define PSURGE_QUAD_COTTON      2
#define PSURGE_QUAD_ICEGRASS    3

/* what sort of powersurge board we have */
static int psurge_type = PSURGE_NONE;

/*
 * Set and clear IPIs for powersurge.
 */
static inline void psurge_set_ipi(int cpu)
{
        if (psurge_type == PSURGE_NONE)
                return;
        if (cpu == 0)
                in_be32(psurge_pri_intr);
        else if (psurge_type == PSURGE_DUAL)
                out_8(psurge_sec_intr, 0);
        else
                PSURGE_QUAD_OUT(PSURGE_QUAD_IRQ_SET, 1 << cpu);
}

static inline void psurge_clr_ipi(int cpu)
{
        if (cpu > 0) {
                switch(psurge_type) {
                case PSURGE_DUAL:
                        out_8(psurge_sec_intr, ~0);
                case PSURGE_NONE:
                        break;
                default:
                        PSURGE_QUAD_OUT(PSURGE_QUAD_IRQ_CLR, 1 << cpu);
                }
        }
}

/*
 * On powersurge (old SMP powermac architecture) we don't have
 * separate IPIs for separate messages like openpic does.  Instead
 * we have a bitmap for each processor, where a 1 bit means that
 * the corresponding message is pending for that processor.
 * Ideally each cpu's entry would be in a different cache line.
 *  -- paulus.
 */
static unsigned long psurge_smp_message[NR_CPUS];

void psurge_smp_message_recv(void)
{
        int cpu = smp_processor_id();
        int msg;

        /* clear interrupt */
        psurge_clr_ipi(cpu);

        if (num_online_cpus() < 2)
                return;

        /* make sure there is a message there */
        for (msg = 0; msg < 4; msg++)
                if (test_and_clear_bit(msg, &psurge_smp_message[cpu]))
                        smp_message_recv(msg);
}

irqreturn_t psurge_primary_intr(int irq, void *d)
{
        psurge_smp_message_recv();
        return IRQ_HANDLED;
}

static void smp_psurge_message_pass(int target, int msg)
{
        int i;

        if (num_online_cpus() < 2)
                return;

        for_each_online_cpu(i) {
                if (target == MSG_ALL
                    || (target == MSG_ALL_BUT_SELF && i != smp_processor_id())
                    || target == i) {
                        set_bit(msg, &psurge_smp_message[i]);
                        psurge_set_ipi(i);
                }
        }
}

/*
 * Determine a quad card presence. We read the board ID register, we
 * force the data bus to change to something else, and we read it again.
 * It it's stable, then the register probably exist (ugh !)
 */
static int __init psurge_quad_probe(void)
{
        int type;
        unsigned int i;

        type = PSURGE_QUAD_IN(PSURGE_QUAD_BOARD_ID);
        if (type < PSURGE_QUAD_OKEE || type > PSURGE_QUAD_ICEGRASS
            || type != PSURGE_QUAD_IN(PSURGE_QUAD_BOARD_ID))
                return PSURGE_DUAL;

        /* looks OK, try a slightly more rigorous test */
        /* bogus is not necessarily cacheline-aligned,
           though I don't suppose that really matters.  -- paulus */
        for (i = 0; i < 100; i++) {
                volatile u32 bogus[8];
                bogus[(0+i)%8] = 0x00000000;
                bogus[(1+i)%8] = 0x55555555;
                bogus[(2+i)%8] = 0xFFFFFFFF;
                bogus[(3+i)%8] = 0xAAAAAAAA;
                bogus[(4+i)%8] = 0x33333333;
                bogus[(5+i)%8] = 0xCCCCCCCC;
                bogus[(6+i)%8] = 0xCCCCCCCC;
                bogus[(7+i)%8] = 0x33333333;
                wmb();
                asm volatile("dcbf 0,%0" : : "r" (bogus) : "memory");
                mb();
                if (type != PSURGE_QUAD_IN(PSURGE_QUAD_BOARD_ID))
                        return PSURGE_DUAL;
        }
        return type;
}

static void __init psurge_quad_init(void)
{
        int procbits;

        if (ppc_md.progress) ppc_md.progress("psurge_quad_init", 0x351);
        procbits = ~PSURGE_QUAD_IN(PSURGE_QUAD_WHICH_CPU);
        if (psurge_type == PSURGE_QUAD_ICEGRASS)
                PSURGE_QUAD_BIS(PSURGE_QUAD_RESET_CTL, procbits);
        else
                PSURGE_QUAD_BIC(PSURGE_QUAD_CKSTOP_CTL, procbits);
        mdelay(33);
        out_8(psurge_sec_intr, ~0);
        PSURGE_QUAD_OUT(PSURGE_QUAD_IRQ_CLR, procbits);
        PSURGE_QUAD_BIS(PSURGE_QUAD_RESET_CTL, procbits);
        if (psurge_type != PSURGE_QUAD_ICEGRASS)
                PSURGE_QUAD_BIS(PSURGE_QUAD_CKSTOP_CTL, procbits);
        PSURGE_QUAD_BIC(PSURGE_QUAD_PRIMARY_ARB, procbits);
        mdelay(33);
        PSURGE_QUAD_BIC(PSURGE_QUAD_RESET_CTL, procbits);
        mdelay(33);
        PSURGE_QUAD_BIS(PSURGE_QUAD_PRIMARY_ARB, procbits);
        mdelay(33);
}

static int __init smp_psurge_probe(void)
{
        int i, ncpus;
        struct device_node *dn;

        /* We don't do SMP on the PPC601 -- paulus */
        if (PVR_VER(mfspr(SPRN_PVR)) == 1)
                return 1;

        /*
         * The powersurge cpu board can be used in the generation
         * of powermacs that have a socket for an upgradeable cpu card,
         * including the 7500, 8500, 9500, 9600.
         * The device tree doesn't tell you if you have 2 cpus because
         * OF doesn't know anything about the 2nd processor.
         * Instead we look for magic bits in magic registers,
         * in the hammerhead memory controller in the case of the
         * dual-cpu powersurge board.  -- paulus.
         */
        dn = of_find_node_by_name(NULL, "hammerhead");
        if (dn == NULL)
                return 1;
        of_node_put(dn);

        hhead_base = ioremap(HAMMERHEAD_BASE, 0x800);
        quad_base = ioremap(PSURGE_QUAD_REG_ADDR, 1024);
        psurge_sec_intr = hhead_base + HHEAD_SEC_INTR;

        psurge_type = psurge_quad_probe();
        if (psurge_type != PSURGE_DUAL) {
                psurge_quad_init();
                /* All released cards using this HW design have 4 CPUs */
                ncpus = 4;
                /* No sure how timebase sync works on those, let's use SW */
                smp_ops->give_timebase = smp_generic_give_timebase;
                smp_ops->take_timebase = smp_generic_take_timebase;
        } else {
                iounmap(quad_base);
                if ((in_8(hhead_base + HHEAD_CONFIG) & 0x02) == 0) {
                        /* not a dual-cpu card */
                        iounmap(hhead_base);
                        psurge_type = PSURGE_NONE;
                        return 1;
                }
                ncpus = 2;
        }

        psurge_start = ioremap(PSURGE_START, 4);
        psurge_pri_intr = ioremap(PSURGE_PRI_INTR, 4);

        /* This is necessary because OF doesn't know about the
         * secondary cpu(s), and thus there aren't nodes in the
         * device tree for them, and smp_setup_cpu_maps hasn't
         * set their bits in cpu_present_mask.
         */
        if (ncpus > NR_CPUS)
                ncpus = NR_CPUS;
        for (i = 1; i < ncpus ; ++i)
                set_cpu_present(i, true);

        if (ppc_md.progress) ppc_md.progress("smp_psurge_probe - done", 0x352);

        return ncpus;
}

static int __init smp_psurge_kick_cpu(int nr)
{
        unsigned long start = __pa(__secondary_start_pmac_0) + nr * 8;
        unsigned long a, flags;
        int i, j;

        /* Defining this here is evil ... but I prefer hiding that
         * crap to avoid giving people ideas that they can do the
         * same.
         */
        extern volatile unsigned int cpu_callin_map[NR_CPUS];

        /* may need to flush here if secondary bats aren't setup */
        for (a = KERNELBASE; a < KERNELBASE + 0x800000; a += 32)
                asm volatile("dcbf 0,%0" : : "r" (a) : "memory");
        asm volatile("sync");

        if (ppc_md.progress) ppc_md.progress("smp_psurge_kick_cpu", 0x353);

        /* This is going to freeze the timeebase, we disable interrupts */
        local_irq_save(flags);

        out_be32(psurge_start, start);
        mb();

        psurge_set_ipi(nr);

        /*
         * We can't use udelay here because the timebase is now frozen.
         */
        for (i = 0; i < 2000; ++i)
                asm volatile("nop" : : : "memory");
        psurge_clr_ipi(nr);

        /*
         * Also, because the timebase is frozen, we must not return to the
         * caller which will try to do udelay's etc... Instead, we wait -here-
         * for the CPU to callin.
         */
        for (i = 0; i < 100000 && !cpu_callin_map[nr]; ++i) {
                for (j = 1; j < 10000; j++)
                        asm volatile("nop" : : : "memory");
                asm volatile("sync" : : : "memory");
        }
        if (!cpu_callin_map[nr])
                goto stuck;

        /* And we do the TB sync here too for standard dual CPU cards */
        if (psurge_type == PSURGE_DUAL) {
                while(!tb_req)
                        barrier();
                tb_req = 0;
                mb();
                timebase = get_tb();
                mb();
                while (timebase)
                        barrier();
                mb();
        }
 stuck:
        /* now interrupt the secondary, restarting both TBs */
        if (psurge_type == PSURGE_DUAL)
                psurge_set_ipi(1);

        if (ppc_md.progress) ppc_md.progress("smp_psurge_kick_cpu - done", 0x354);

        return 0;
}

static struct irqaction psurge_irqaction = {
        .handler = psurge_primary_intr,
        .flags = IRQF_DISABLED,
        .name = "primary IPI",
};

static void __init smp_psurge_setup_cpu(int cpu_nr)
{
        if (cpu_nr != 0)
                return;

        /* reset the entry point so if we get another intr we won't
         * try to startup again */
        out_be32(psurge_start, 0x100);
        if (setup_irq(irq_create_mapping(NULL, 30), &psurge_irqaction))
                printk(KERN_ERR "Couldn't get primary IPI interrupt");
}

void __init smp_psurge_take_timebase(void)
{
        if (psurge_type != PSURGE_DUAL)
                return;

        tb_req = 1;
        mb();
        while (!timebase)
                barrier();
        mb();
        set_tb(timebase >> 32, timebase & 0xffffffff);
        timebase = 0;
        mb();
        set_dec(tb_ticks_per_jiffy/2);
}

void __init smp_psurge_give_timebase(void)
{
        /* Nothing to do here */
}

/* PowerSurge-style Macs */
struct smp_ops_t psurge_smp_ops = {
        .message_pass   = smp_psurge_message_pass,
        .probe          = smp_psurge_probe,
        .kick_cpu       = smp_psurge_kick_cpu,
        .setup_cpu      = smp_psurge_setup_cpu,
        .give_timebase  = smp_psurge_give_timebase,
        .take_timebase  = smp_psurge_take_timebase,
};
#endif /* CONFIG_PPC32 - actually powersurge support */

/*
 * Core 99 and later support
 */


static void smp_core99_give_timebase(void)
{
        unsigned long flags;

        local_irq_save(flags);

        while(!tb_req)
                barrier();
        tb_req = 0;
        (*pmac_tb_freeze)(1);
        mb();
        timebase = get_tb();
        mb();
        while (timebase)
                barrier();
        mb();
        (*pmac_tb_freeze)(0);
        mb();

        local_irq_restore(flags);
}


static void __devinit smp_core99_take_timebase(void)
{
        unsigned long flags;

        local_irq_save(flags);

        tb_req = 1;
        mb();
        while (!timebase)
                barrier();
        mb();
        set_tb(timebase >> 32, timebase & 0xffffffff);
        timebase = 0;
        mb();

        local_irq_restore(flags);
}

#ifdef CONFIG_PPC64
/*
 * G5s enable/disable the timebase via an i2c-connected clock chip.
 */
static struct pmac_i2c_bus *pmac_tb_clock_chip_host;
static u8 pmac_tb_pulsar_addr;

static void smp_core99_cypress_tb_freeze(int freeze)
{
        u8 data;
        int rc;

        /* Strangely, the device-tree says address is 0xd2, but darwin
         * accesses 0xd0 ...
         */
        pmac_i2c_setmode(pmac_tb_clock_chip_host,
                         pmac_i2c_mode_combined);
        rc = pmac_i2c_xfer(pmac_tb_clock_chip_host,
                           0xd0 | pmac_i2c_read,
                           1, 0x81, &data, 1);
        if (rc != 0)
                goto bail;

        data = (data & 0xf3) | (freeze ? 0x00 : 0x0c);

        pmac_i2c_setmode(pmac_tb_clock_chip_host, pmac_i2c_mode_stdsub);
        rc = pmac_i2c_xfer(pmac_tb_clock_chip_host,
                           0xd0 | pmac_i2c_write,
                           1, 0x81, &data, 1);

 bail:
        if (rc != 0) {
                printk("Cypress Timebase %s rc: %d\n",
                       freeze ? "freeze" : "unfreeze", rc);
                panic("Timebase freeze failed !\n");
        }
}


static void smp_core99_pulsar_tb_freeze(int freeze)
{
        u8 data;
        int rc;

        pmac_i2c_setmode(pmac_tb_clock_chip_host,
                         pmac_i2c_mode_combined);
        rc = pmac_i2c_xfer(pmac_tb_clock_chip_host,
                           pmac_tb_pulsar_addr | pmac_i2c_read,
                           1, 0x2e, &data, 1);
        if (rc != 0)
                goto bail;

        data = (data & 0x88) | (freeze ? 0x11 : 0x22);

        pmac_i2c_setmode(pmac_tb_clock_chip_host, pmac_i2c_mode_stdsub);
        rc = pmac_i2c_xfer(pmac_tb_clock_chip_host,
                           pmac_tb_pulsar_addr | pmac_i2c_write,
                           1, 0x2e, &data, 1);
 bail:
        if (rc != 0) {
                printk(KERN_ERR "Pulsar Timebase %s rc: %d\n",
                       freeze ? "freeze" : "unfreeze", rc);
                panic("Timebase freeze failed !\n");
        }
}

static void __init smp_core99_setup_i2c_hwsync(int ncpus)
{
        struct device_node *cc = NULL;  
        struct device_node *p;
        const char *name = NULL;
        const u32 *reg;
        int ok;

        /* Look for the clock chip */
        while ((cc = of_find_node_by_name(cc, "i2c-hwclock")) != NULL) {
                p = of_get_parent(cc);
                ok = p && of_device_is_compatible(p, "uni-n-i2c");
                of_node_put(p);
                if (!ok)
                        continue;

                pmac_tb_clock_chip_host = pmac_i2c_find_bus(cc);
                if (pmac_tb_clock_chip_host == NULL)
                        continue;
                reg = of_get_property(cc, "reg", NULL);
                if (reg == NULL)
                        continue;
                switch (*reg) {
                case 0xd2:
                        if (of_device_is_compatible(cc,"pulsar-legacy-slewing")) {
                                pmac_tb_freeze = smp_core99_pulsar_tb_freeze;
                                pmac_tb_pulsar_addr = 0xd2;
                                name = "Pulsar";
                        } else if (of_device_is_compatible(cc, "cy28508")) {
                                pmac_tb_freeze = smp_core99_cypress_tb_freeze;
                                name = "Cypress";
                        }
                        break;
                case 0xd4:
                        pmac_tb_freeze = smp_core99_pulsar_tb_freeze;
                        pmac_tb_pulsar_addr = 0xd4;
                        name = "Pulsar";
                        break;
                }
                if (pmac_tb_freeze != NULL)
                        break;
        }
        if (pmac_tb_freeze != NULL) {
                /* Open i2c bus for synchronous access */
                if (pmac_i2c_open(pmac_tb_clock_chip_host, 1)) {
                        printk(KERN_ERR "Failed top open i2c bus for clock"
                               " sync, fallback to software sync !\n");
                        goto no_i2c_sync;
                }
                printk(KERN_INFO "Processor timebase sync using %s i2c clock\n",
                       name);
                return;
        }
 no_i2c_sync:
        pmac_tb_freeze = NULL;
        pmac_tb_clock_chip_host = NULL;
}



/*
 * Newer G5s uses a platform function
 */

static void smp_core99_pfunc_tb_freeze(int freeze)
{
        struct device_node *cpus;
        struct pmf_args args;

        cpus = of_find_node_by_path("/cpus");
        BUG_ON(cpus == NULL);
        args.count = 1;
        args.u[0].v = !freeze;
        pmf_call_function(cpus, "cpu-timebase", &args);
        of_node_put(cpus);
}

#else /* CONFIG_PPC64 */

/*
 * SMP G4 use a GPIO to enable/disable the timebase.
 */

static unsigned int core99_tb_gpio;     /* Timebase freeze GPIO */

static void smp_core99_gpio_tb_freeze(int freeze)
{
        if (freeze)
                pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, core99_tb_gpio, 4);
        else
                pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, core99_tb_gpio, 0);
        pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, core99_tb_gpio, 0);
}


#endif /* !CONFIG_PPC64 */

/* L2 and L3 cache settings to pass from CPU0 to CPU1 on G4 cpus */
volatile static long int core99_l2_cache;
volatile static long int core99_l3_cache;

static void __devinit core99_init_caches(int cpu)
{
#ifndef CONFIG_PPC64
        if (!cpu_has_feature(CPU_FTR_L2CR))
                return;

        if (cpu == 0) {
                core99_l2_cache = _get_L2CR();
                printk("CPU0: L2CR is %lx\n", core99_l2_cache);
        } else {
                printk("CPU%d: L2CR was %lx\n", cpu, _get_L2CR());
                _set_L2CR(0);
                _set_L2CR(core99_l2_cache);
                printk("CPU%d: L2CR set to %lx\n", cpu, core99_l2_cache);
        }

        if (!cpu_has_feature(CPU_FTR_L3CR))
                return;

        if (cpu == 0){
                core99_l3_cache = _get_L3CR();
                printk("CPU0: L3CR is %lx\n", core99_l3_cache);
        } else {
                printk("CPU%d: L3CR was %lx\n", cpu, _get_L3CR());
                _set_L3CR(0);
                _set_L3CR(core99_l3_cache);
                printk("CPU%d: L3CR set to %lx\n", cpu, core99_l3_cache);
        }
#endif /* !CONFIG_PPC64 */
}

static void __init smp_core99_setup(int ncpus)
{
#ifdef CONFIG_PPC64

        /* i2c based HW sync on some G5s */
        if (of_machine_is_compatible("PowerMac7,2") ||
            of_machine_is_compatible("PowerMac7,3") ||
            of_machine_is_compatible("RackMac3,1"))
                smp_core99_setup_i2c_hwsync(ncpus);

        /* pfunc based HW sync on recent G5s */
        if (pmac_tb_freeze == NULL) {
                struct device_node *cpus =
                        of_find_node_by_path("/cpus");
                if (cpus &&
                    of_get_property(cpus, "platform-cpu-timebase", NULL)) {
                        pmac_tb_freeze = smp_core99_pfunc_tb_freeze;
                        printk(KERN_INFO "Processor timebase sync using"
                               " platform function\n");
                }
        }

#else /* CONFIG_PPC64 */

        /* GPIO based HW sync on ppc32 Core99 */
        if (pmac_tb_freeze == NULL && !of_machine_is_compatible("MacRISC4")) {
                struct device_node *cpu;
                const u32 *tbprop = NULL;

                core99_tb_gpio = KL_GPIO_TB_ENABLE;     /* default value */
                cpu = of_find_node_by_type(NULL, "cpu");
                if (cpu != NULL) {
                        tbprop = of_get_property(cpu, "timebase-enable", NULL);
                        if (tbprop)
                                core99_tb_gpio = *tbprop;
                        of_node_put(cpu);
                }
                pmac_tb_freeze = smp_core99_gpio_tb_freeze;
                printk(KERN_INFO "Processor timebase sync using"
                       " GPIO 0x%02x\n", core99_tb_gpio);
        }

#endif /* CONFIG_PPC64 */

        /* No timebase sync, fallback to software */
        if (pmac_tb_freeze == NULL) {
                smp_ops->give_timebase = smp_generic_give_timebase;
                smp_ops->take_timebase = smp_generic_take_timebase;
                printk(KERN_INFO "Processor timebase sync using software\n");
        }

#ifndef CONFIG_PPC64
        {
                int i;

                /* XXX should get this from reg properties */
                for (i = 1; i < ncpus; ++i)
                        set_hard_smp_processor_id(i, i);
        }
#endif

        /* 32 bits SMP can't NAP */
        if (!of_machine_is_compatible("MacRISC4"))
                powersave_nap = 0;
}

static int __init smp_core99_probe(void)
{
        struct device_node *cpus;
        int ncpus = 0;

        if (ppc_md.progress) ppc_md.progress("smp_core99_probe", 0x345);

        /* Count CPUs in the device-tree */
        for (cpus = NULL; (cpus = of_find_node_by_type(cpus, "cpu")) != NULL;)
                ++ncpus;

        printk(KERN_INFO "PowerMac SMP probe found %d cpus\n", ncpus);

        /* Nothing more to do if less than 2 of them */
        if (ncpus <= 1)
                return 1;

        /* We need to perform some early initialisations before we can start
         * setting up SMP as we are running before initcalls
         */
        pmac_pfunc_base_install();
        pmac_i2c_init();

        /* Setup various bits like timebase sync method, ability to nap, ... */
        smp_core99_setup(ncpus);

        /* Install IPIs */
        mpic_request_ipis();

        /* Collect l2cr and l3cr values from CPU 0 */
        core99_init_caches(0);

        return ncpus;
}

static int __devinit smp_core99_kick_cpu(int nr)
{
        unsigned int save_vector;
        unsigned long target, flags;
        unsigned int *vector = (unsigned int *)(PAGE_OFFSET+0x100);

        if (nr < 0 || nr > 3)
                return -ENOENT;

        if (ppc_md.progress)
                ppc_md.progress("smp_core99_kick_cpu", 0x346);

        local_irq_save(flags);

        /* Save reset vector */
        save_vector = *vector;

        /* Setup fake reset vector that does
         *   b __secondary_start_pmac_0 + nr*8
         */
        target = (unsigned long) __secondary_start_pmac_0 + nr * 8;
        patch_branch(vector, target, BRANCH_SET_LINK);

        /* Put some life in our friend */
        pmac_call_feature(PMAC_FTR_RESET_CPU, NULL, nr, 0);

        /* FIXME: We wait a bit for the CPU to take the exception, I should
         * instead wait for the entry code to set something for me. Well,
         * ideally, all that crap will be done in prom.c and the CPU left
         * in a RAM-based wait loop like CHRP.
         */
        mdelay(1);

        /* Restore our exception vector */
        *vector = save_vector;
        flush_icache_range((unsigned long) vector, (unsigned long) vector + 4);

        local_irq_restore(flags);
        if (ppc_md.progress) ppc_md.progress("smp_core99_kick_cpu done", 0x347);

        return 0;
}

static void __devinit smp_core99_setup_cpu(int cpu_nr)
{
        /* Setup L2/L3 */
        if (cpu_nr != 0)
                core99_init_caches(cpu_nr);

        /* Setup openpic */
        mpic_setup_this_cpu();
}

#ifdef CONFIG_PPC64
#ifdef CONFIG_HOTPLUG_CPU
static int smp_core99_cpu_notify(struct notifier_block *self,
                                 unsigned long action, void *hcpu)
{
        int rc;

        switch(action) {
        case CPU_UP_PREPARE:
        case CPU_UP_PREPARE_FROZEN:
                /* Open i2c bus if it was used for tb sync */
                if (pmac_tb_clock_chip_host) {
                        rc = pmac_i2c_open(pmac_tb_clock_chip_host, 1);
                        if (rc) {
                                pr_err("Failed to open i2c bus for time sync\n");
                                return notifier_from_errno(rc);
                        }
                }
                break;
        case CPU_ONLINE:
        case CPU_UP_CANCELED:
                /* Close i2c bus if it was used for tb sync */
                if (pmac_tb_clock_chip_host)
                        pmac_i2c_close(pmac_tb_clock_chip_host);
                break;
        default:
                break;
        }
        return NOTIFY_OK;
}

static struct notifier_block __cpuinitdata smp_core99_cpu_nb = {
        .notifier_call  = smp_core99_cpu_notify,
};
#endif /* CONFIG_HOTPLUG_CPU */

static void __init smp_core99_bringup_done(void)
{
        extern void g5_phy_disable_cpu1(void);

        /* Close i2c bus if it was used for tb sync */
        if (pmac_tb_clock_chip_host)
                pmac_i2c_close(pmac_tb_clock_chip_host);

        /* If we didn't start the second CPU, we must take
         * it off the bus.
         */
        if (of_machine_is_compatible("MacRISC4") &&
            num_online_cpus() < 2) {
                set_cpu_present(1, false);
                g5_phy_disable_cpu1();
        }
#ifdef CONFIG_HOTPLUG_CPU
        register_cpu_notifier(&smp_core99_cpu_nb);
#endif

        if (ppc_md.progress)
                ppc_md.progress("smp_core99_bringup_done", 0x349);
}
#endif /* CONFIG_PPC64 */

#ifdef CONFIG_HOTPLUG_CPU

static int smp_core99_cpu_disable(void)
{
        int rc = generic_cpu_disable();
        if (rc)
                return rc;

        mpic_cpu_set_priority(0xf);

        return 0;
}

#ifdef CONFIG_PPC32

static void pmac_cpu_die(void)
{
        int cpu = smp_processor_id();

        local_irq_disable();
        idle_task_exit();
        pr_debug("CPU%d offline\n", cpu);
        generic_set_cpu_dead(cpu);
        smp_wmb();
        mb();
        low_cpu_die();
}

#else /* CONFIG_PPC32 */

static void pmac_cpu_die(void)
{
        int cpu = smp_processor_id();

        local_irq_disable();
        idle_task_exit();

        /*
         * turn off as much as possible, we'll be
         * kicked out as this will only be invoked
         * on core99 platforms for now ...
         */

        printk(KERN_INFO "CPU#%d offline\n", cpu);
        generic_set_cpu_dead(cpu);
        smp_wmb();

        /*
         * Re-enable interrupts. The NAP code needs to enable them
         * anyways, do it now so we deal with the case where one already
         * happened while soft-disabled.
         * We shouldn't get any external interrupts, only decrementer, and the
         * decrementer handler is safe for use on offline CPUs
         */
        local_irq_enable();

        while (1) {
                /* let's not take timer interrupts too often ... */
                set_dec(0x7fffffff);

                /* Enter NAP mode */
                power4_idle();
        }
}

#endif /* else CONFIG_PPC32 */
#endif /* CONFIG_HOTPLUG_CPU */

/* Core99 Macs (dual G4s and G5s) */
struct smp_ops_t core99_smp_ops = {
        .message_pass   = smp_mpic_message_pass,
        .probe          = smp_core99_probe,
#ifdef CONFIG_PPC64
        .bringup_done   = smp_core99_bringup_done,
#endif
        .kick_cpu       = smp_core99_kick_cpu,
        .setup_cpu      = smp_core99_setup_cpu,
        .give_timebase  = smp_core99_give_timebase,
        .take_timebase  = smp_core99_take_timebase,
#if defined(CONFIG_HOTPLUG_CPU)
        .cpu_disable    = smp_core99_cpu_disable,
        .cpu_die        = generic_cpu_die,
#endif
};

void __init pmac_setup_smp(void)
{
        struct device_node *np;

        /* Check for Core99 */
        np = of_find_node_by_name(NULL, "uni-n");
        if (!np)
                np = of_find_node_by_name(NULL, "u3");
        if (!np)
                np = of_find_node_by_name(NULL, "u4");
        if (np) {
                of_node_put(np);
                smp_ops = &core99_smp_ops;
        }
#ifdef CONFIG_PPC32
        else {
                /* We have to set bits in cpu_possible_mask here since the
                 * secondary CPU(s) aren't in the device tree. Various
                 * things won't be initialized for CPUs not in the possible
                 * map, so we really need to fix it up here.
                 */
                int cpu;

                for (cpu = 1; cpu < 4 && cpu < NR_CPUS; ++cpu)
                        set_cpu_possible(cpu, true);
                smp_ops = &psurge_smp_ops;
        }
#endif /* CONFIG_PPC32 */

#ifdef CONFIG_HOTPLUG_CPU
        ppc_md.cpu_die = pmac_cpu_die;
#endif
}