leon_smp.c

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/* leon_smp.c: Sparc-Leon SMP support.
 *
 * based on sun4m_smp.c
 * Copyright (C) 1996 David S. Miller ([email protected])
 * Copyright (C) 2009 Daniel Hellstrom ([email protected]) Aeroflex Gaisler AB
 * Copyright (C) 2009 Konrad Eisele ([email protected]) Aeroflex Gaisler AB
 */

#include <asm/head.h>

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/threads.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/of.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/profile.h>
#include <linux/pm.h>
#include <linux/delay.h>
#include <linux/gfp.h>
#include <linux/cpu.h>
#include <linux/clockchips.h>

#include <asm/cacheflush.h>
#include <asm/tlbflush.h>

#include <asm/ptrace.h>
#include <linux/atomic.h>
#include <asm/irq_regs.h>
#include <asm/traps.h>

#include <asm/delay.h>
#include <asm/irq.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/oplib.h>
#include <asm/cpudata.h>
#include <asm/asi.h>
#include <asm/leon.h>
#include <asm/leon_amba.h>
#include <asm/timer.h>

#include "kernel.h"

#include "irq.h"

extern ctxd_t *srmmu_ctx_table_phys;
static int smp_processors_ready;
extern volatile unsigned long cpu_callin_map[NR_CPUS];
extern cpumask_t smp_commenced_mask;
void __cpuinit leon_configure_cache_smp(void);
static void leon_ipi_init(void);

/* IRQ number of LEON IPIs */
int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;

static inline unsigned long do_swap(volatile unsigned long *ptr,
                    unsigned long val)
{
    __asm__ __volatile__("swapa [%2] %3, %0\n\t" : "=&r"(val)
                 : "0"(val), "r"(ptr), "i"(ASI_LEON_DCACHE_MISS)
                 : "memory");
    return val;
}

void __cpuinit leon_callin(void)
{
    int cpuid = hard_smp_processor_id();

    local_ops->cache_all();
    local_ops->tlb_all();
    leon_configure_cache_smp();

    notify_cpu_starting(cpuid);

    /* Get our local ticker going. */
    register_percpu_ce(cpuid);

    calibrate_delay();
    smp_store_cpu_info(cpuid);

    local_ops->cache_all();
    local_ops->tlb_all();

    /*
     * Unblock the master CPU _only_ when the scheduler state
     * of all secondary CPUs will be up-to-date, so after
     * the SMP initialization the master will be just allowed
     * to call the scheduler code.
     * Allow master to continue.
     */
    do_swap(&cpu_callin_map[cpuid], 1);

    local_ops->cache_all();
    local_ops->tlb_all();

    /* Fix idle thread fields. */
    __asm__ __volatile__("ld [%0], %%g6\n\t" : : "r"(&current_set[cpuid])
                 : "memory" /* paranoid */);

    /* Attach to the address space of init_task. */
    atomic_inc(&init_mm.mm_count);
    current->active_mm = &init_mm;

    while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
        mb();

    local_irq_enable();
    set_cpu_online(cpuid, true);
}

/*
 *  Cycle through the processors asking the PROM to start each one.
 */

extern struct linux_prom_registers smp_penguin_ctable;

void __cpuinit leon_configure_cache_smp(void)
{
    unsigned long cfg = sparc_leon3_get_dcachecfg();
    int me = smp_processor_id();

    if (ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg) > 4) {
        printk(KERN_INFO "Note: SMP with snooping only works on 4k cache, found %dk(0x%x) on cpu %d, disabling caches\n",
             (unsigned int)ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg),
             (unsigned int)cfg, (unsigned int)me);
        sparc_leon3_disable_cache();
    } else {
        if (cfg & ASI_LEON3_SYSCTRL_CFG_SNOOPING) {
            sparc_leon3_enable_snooping();
        } else {
            printk(KERN_INFO "Note: You have to enable snooping in the vhdl model cpu %d, disabling caches\n",
                 me);
            sparc_leon3_disable_cache();
        }
    }

    local_ops->cache_all();
    local_ops->tlb_all();
}

void leon_smp_setbroadcast(unsigned int mask)
{
    int broadcast =
        ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
          LEON3_IRQMPSTATUS_BROADCAST) & 1);
    if (!broadcast) {
        prom_printf("######## !!!! The irqmp-ctrl must have broadcast enabled, smp wont work !!!!! ####### nr cpus: %d\n",
             leon_smp_nrcpus());
        if (leon_smp_nrcpus() > 1) {
            BUG();
        } else {
            prom_printf("continue anyway\n");
            return;
        }
    }
    LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpbroadcast), mask);
}

unsigned int leon_smp_getbroadcast(void)
{
    unsigned int mask;
    mask = LEON_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpbroadcast));
    return mask;
}

int leon_smp_nrcpus(void)
{
    int nrcpu =
        ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
          LEON3_IRQMPSTATUS_CPUNR) & 0xf) + 1;
    return nrcpu;
}

void __init leon_boot_cpus(void)
{
    int nrcpu = leon_smp_nrcpus();
    int me = smp_processor_id();

    /* Setup IPI */
    leon_ipi_init();

    printk(KERN_INFO "%d:(%d:%d) cpus mpirq at 0x%x\n", (unsigned int)me,
           (unsigned int)nrcpu, (unsigned int)NR_CPUS,
           (unsigned int)&(leon3_irqctrl_regs->mpstatus));

    leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, me);
    leon_enable_irq_cpu(LEON3_IRQ_TICKER, me);
    leon_enable_irq_cpu(leon_ipi_irq, me);

    leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);

    leon_configure_cache_smp();
    local_ops->cache_all();

}

int __cpuinit leon_boot_one_cpu(int i, struct task_struct *idle)
{
    int timeout;

    current_set[i] = task_thread_info(idle);

    /* See trampoline.S:leon_smp_cpu_startup for details...
     * Initialize the contexts table
     * Since the call to prom_startcpu() trashes the structure,
     * we need to re-initialize it for each cpu
     */
    smp_penguin_ctable.which_io = 0;
    smp_penguin_ctable.phys_addr = (unsigned int)srmmu_ctx_table_phys;
    smp_penguin_ctable.reg_size = 0;

    /* whirrr, whirrr, whirrrrrrrrr... */
    printk(KERN_INFO "Starting CPU %d : (irqmp: 0x%x)\n", (unsigned int)i,
           (unsigned int)&leon3_irqctrl_regs->mpstatus);
    local_ops->cache_all();

    /* Make sure all IRQs are of from the start for this new CPU */
    LEON_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[i], 0);

    /* Wake one CPU */
    LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpstatus), 1 << i);

    /* wheee... it's going... */
    for (timeout = 0; timeout < 10000; timeout++) {
        if (cpu_callin_map[i])
            break;
        udelay(200);
    }
    printk(KERN_INFO "Started CPU %d\n", (unsigned int)i);

    if (!(cpu_callin_map[i])) {
        printk(KERN_ERR "Processor %d is stuck.\n", i);
        return -ENODEV;
    } else {
        leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, i);
        leon_enable_irq_cpu(LEON3_IRQ_TICKER, i);
        leon_enable_irq_cpu(leon_ipi_irq, i);
    }

    local_ops->cache_all();
    return 0;
}

void __init leon_smp_done(void)
{

    int i, first;
    int *prev;

    /* setup cpu list for irq rotation */
    first = 0;
    prev = &first;
    for (i = 0; i < NR_CPUS; i++) {
        if (cpu_online(i)) {
            *prev = i;
            prev = &cpu_data(i).next;
        }
    }
    *prev = first;
    local_ops->cache_all();

    /* Free unneeded trap tables */
    if (!cpu_present(1)) {
        ClearPageReserved(virt_to_page(&trapbase_cpu1));
        init_page_count(virt_to_page(&trapbase_cpu1));
        free_page((unsigned long)&trapbase_cpu1);
        totalram_pages++;
        num_physpages++;
    }
    if (!cpu_present(2)) {
        ClearPageReserved(virt_to_page(&trapbase_cpu2));
        init_page_count(virt_to_page(&trapbase_cpu2));
        free_page((unsigned long)&trapbase_cpu2);
        totalram_pages++;
        num_physpages++;
    }
    if (!cpu_present(3)) {
        ClearPageReserved(virt_to_page(&trapbase_cpu3));
        init_page_count(virt_to_page(&trapbase_cpu3));
        free_page((unsigned long)&trapbase_cpu3);
        totalram_pages++;
        num_physpages++;
    }
    /* Ok, they are spinning and ready to go. */
    smp_processors_ready = 1;

}

void leon_irq_rotate(int cpu)
{
}

struct leon_ipi_work {
    int single;
    int msk;
    int resched;
};

static DEFINE_PER_CPU_SHARED_ALIGNED(struct leon_ipi_work, leon_ipi_work);

/* Initialize IPIs on the LEON, in order to save IRQ resources only one IRQ
 * is used for all three types of IPIs.
 */
static void __init leon_ipi_init(void)
{
    int cpu, len;
    struct leon_ipi_work *work;
    struct property *pp;
    struct device_node *rootnp;
    struct tt_entry *trap_table;
    unsigned long flags;

    /* Find IPI IRQ or stick with default value */
    rootnp = of_find_node_by_path("/ambapp0");
    if (rootnp) {
        pp = of_find_property(rootnp, "ipi_num", &len);
        if (pp && (*(int *)pp->value))
            leon_ipi_irq = *(int *)pp->value;
    }
    printk(KERN_INFO "leon: SMP IPIs at IRQ %d\n", leon_ipi_irq);

    /* Adjust so that we jump directly to smpleon_ipi */
    local_irq_save(flags);
    trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (leon_ipi_irq - 1)];
    trap_table->inst_three += smpleon_ipi - real_irq_entry;
    local_ops->cache_all();
    local_irq_restore(flags);

    for_each_possible_cpu(cpu) {
        work = &per_cpu(leon_ipi_work, cpu);
        work->single = work->msk = work->resched = 0;
    }
}

static void leon_send_ipi(int cpu, int level)
{
    unsigned long mask;
    mask = leon_get_irqmask(level);
    LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->force[cpu], mask);
}

static void leon_ipi_single(int cpu)
{
    struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);

    /* Mark work */
    work->single = 1;

    /* Generate IRQ on the CPU */
    leon_send_ipi(cpu, leon_ipi_irq);
}

static void leon_ipi_mask_one(int cpu)
{
    struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);

    /* Mark work */
    work->msk = 1;

    /* Generate IRQ on the CPU */
    leon_send_ipi(cpu, leon_ipi_irq);
}

static void leon_ipi_resched(int cpu)
{
    struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);

    /* Mark work */
    work->resched = 1;

    /* Generate IRQ on the CPU (any IRQ will cause resched) */
    leon_send_ipi(cpu, leon_ipi_irq);
}

void leonsmp_ipi_interrupt(void)
{
    struct leon_ipi_work *work = &__get_cpu_var(leon_ipi_work);

    if (work->single) {
        work->single = 0;
        smp_call_function_single_interrupt();
    }
    if (work->msk) {
        work->msk = 0;
        smp_call_function_interrupt();
    }
    if (work->resched) {
        work->resched = 0;
        smp_resched_interrupt();
    }
}

static struct smp_funcall {
    smpfunc_t func;
    unsigned long arg1;
    unsigned long arg2;
    unsigned long arg3;
    unsigned long arg4;
    unsigned long arg5;
    unsigned long processors_in[NR_CPUS];   /* Set when ipi entered. */
    unsigned long processors_out[NR_CPUS];  /* Set when ipi exited. */
} ccall_info;

static DEFINE_SPINLOCK(cross_call_lock);

/* Cross calls must be serialized, at least currently. */
static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
                unsigned long arg2, unsigned long arg3,
                unsigned long arg4)
{
    if (smp_processors_ready) {
        register int high = NR_CPUS - 1;
        unsigned long flags;

        spin_lock_irqsave(&cross_call_lock, flags);

        {
            /* If you make changes here, make sure gcc generates proper code... */
            register smpfunc_t f asm("i0") = func;
            register unsigned long a1 asm("i1") = arg1;
            register unsigned long a2 asm("i2") = arg2;
            register unsigned long a3 asm("i3") = arg3;
            register unsigned long a4 asm("i4") = arg4;
            register unsigned long a5 asm("i5") = 0;

            __asm__ __volatile__("std %0, [%6]\n\t"
                         "std %2, [%6 + 8]\n\t"
                         "std %4, [%6 + 16]\n\t" : :
                         "r"(f), "r"(a1), "r"(a2), "r"(a3),
                         "r"(a4), "r"(a5),
                         "r"(&ccall_info.func));
        }

        /* Init receive/complete mapping, plus fire the IPI's off. */
        {
            register int i;

            cpumask_clear_cpu(smp_processor_id(), &mask);
            cpumask_and(&mask, cpu_online_mask, &mask);
            for (i = 0; i <= high; i++) {
                if (cpumask_test_cpu(i, &mask)) {
                    ccall_info.processors_in[i] = 0;
                    ccall_info.processors_out[i] = 0;
                    leon_send_ipi(i, LEON3_IRQ_CROSS_CALL);

                }
            }
        }

        {
            register int i;

            i = 0;
            do {
                if (!cpumask_test_cpu(i, &mask))
                    continue;

                while (!ccall_info.processors_in[i])
                    barrier();
            } while (++i <= high);

            i = 0;
            do {
                if (!cpumask_test_cpu(i, &mask))
                    continue;

                while (!ccall_info.processors_out[i])
                    barrier();
            } while (++i <= high);
        }

        spin_unlock_irqrestore(&cross_call_lock, flags);
    }
}

/* Running cross calls. */
void leon_cross_call_irq(void)
{
    int i = smp_processor_id();

    ccall_info.processors_in[i] = 1;
    ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
            ccall_info.arg4, ccall_info.arg5);
    ccall_info.processors_out[i] = 1;
}

static const struct sparc32_ipi_ops leon_ipi_ops = {
    .cross_call = leon_cross_call,
    .resched    = leon_ipi_resched,
    .single     = leon_ipi_single,
    .mask_one   = leon_ipi_mask_one,
};

void __init leon_init_smp(void)
{
    /* Patch ipi15 trap table */
    t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);

    sparc32_ipi_ops = &leon_ipi_ops;
}