/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include <sys/systm.h>
#include <sys/membar.h>
#include <sys/machsystm.h>
#include <sys/x_call.h>
#include <sys/platform_module.h>
#include <sys/cpuvar.h>
#include <sys/cpu_module.h>
#include <sys/cmp.h>
#include <sys/dumphdr.h>

#include <sys/cpu_sgnblk_defs.h>

static cpuset_t cpu_idle_set;
static kmutex_t cpu_idle_lock;
typedef const char *fn_t;

/*
 * flags to determine if the PROM routines
 * should be used to idle/resume/stop cpus
 */
static int kern_idle[NCPU];             /* kernel's idle loop */
static int cpu_are_paused;
extern void debug_flush_windows();

/*
 * Initialize the idlestop mutex
 */
void
idlestop_init(void)
{
        mutex_init(&cpu_idle_lock, NULL, MUTEX_SPIN, (void *)ipltospl(PIL_15));
}

static void
cpu_idle_self(void)
{
        uint_t s;
        label_t save;

        s = spl8();
        debug_flush_windows();

        CPU->cpu_m.in_prom = 1;
        membar_stld();

        save = curthread->t_pcb;
        (void) setjmp(&curthread->t_pcb);

        kern_idle[CPU->cpu_id] = 1;
        while (kern_idle[CPU->cpu_id])
                dumpsys_helper_nw();

        CPU->cpu_m.in_prom = 0;
        membar_stld();

        curthread->t_pcb = save;
        splx(s);
}

void
idle_other_cpus(void)
{
        int i, cpuid, ntries;
        int failed = 0;

        if (ncpus == 1)
                return;

        mutex_enter(&cpu_idle_lock);

        cpuid = CPU->cpu_id;
        ASSERT(cpuid < NCPU);

        cpu_idle_set = cpu_ready_set;
        CPUSET_DEL(cpu_idle_set, cpuid);

        if (CPUSET_ISNULL(cpu_idle_set))
                return;

        xt_some(cpu_idle_set, (xcfunc_t *)idle_stop_xcall,
            (uint64_t)cpu_idle_self, 0);

        for (i = 0; i < NCPU; i++) {
                if (!CPU_IN_SET(cpu_idle_set, i))
                        continue;

                ntries = 0x10000;
                while (!cpu[i]->cpu_m.in_prom && ntries) {
                        DELAY(50);
                        ntries--;
                }

                /*
                 * A cpu failing to idle is an error condition, since
                 * we can't be sure anymore of its state.
                 */
                if (!cpu[i]->cpu_m.in_prom) {
                        cmn_err(CE_WARN, "cpuid 0x%x failed to idle", i);
                        failed++;
                }
        }

        if (failed) {
                mutex_exit(&cpu_idle_lock);
                cmn_err(CE_PANIC, "idle_other_cpus: not all cpus idled");
        }
}

void
resume_other_cpus(void)
{
        int i, ntries;
        int cpuid = CPU->cpu_id;
        boolean_t failed = B_FALSE;

        if (ncpus == 1)
                return;

        ASSERT(cpuid < NCPU);
        ASSERT(MUTEX_HELD(&cpu_idle_lock));

        for (i = 0; i < NCPU; i++) {
                if (!CPU_IN_SET(cpu_idle_set, i))
                        continue;

                kern_idle[i] = 0;
                membar_stld();
        }

        for (i = 0; i < NCPU; i++) {
                if (!CPU_IN_SET(cpu_idle_set, i))
                        continue;

                ntries = 0x10000;
                while (cpu[i]->cpu_m.in_prom && ntries) {
                        DELAY(50);
                        ntries--;
                }

                /*
                 * A cpu failing to resume is an error condition, since
                 * intrs may have been directed there.
                 */
                if (cpu[i]->cpu_m.in_prom) {
                        cmn_err(CE_WARN, "cpuid 0x%x failed to resume", i);
                        continue;
                }
                CPUSET_DEL(cpu_idle_set, i);
        }

        failed = !CPUSET_ISNULL(cpu_idle_set);

        mutex_exit(&cpu_idle_lock);

        /*
         * Non-zero if a cpu failed to resume
         */
        if (failed)
                cmn_err(CE_PANIC, "resume_other_cpus: not all cpus resumed");

}

/*
 * Stop all other cpu's before halting or rebooting. We pause the cpu's
 * instead of sending a cross call.
 */
void
stop_other_cpus(void)
{
        mutex_enter(&cpu_lock);
        if (cpu_are_paused) {
                mutex_exit(&cpu_lock);
                return;
        }

        if (ncpus > 1)
                intr_redist_all_cpus_shutdown();

        pause_cpus(NULL, NULL);
        cpu_are_paused = 1;

        mutex_exit(&cpu_lock);
}

int cpu_quiesce_microsecond_sanity_limit = 60 * 1000000;

void
mp_cpu_quiesce(cpu_t *cp0)
{

        volatile cpu_t  *cp = (volatile cpu_t *) cp0;
        int i, sanity_limit = cpu_quiesce_microsecond_sanity_limit;
        int             cpuid = cp->cpu_id;
        int             found_intr = 1;
        static fn_t     f = "mp_cpu_quiesce";

        ASSERT(CPU->cpu_id != cpuid);
        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(cp->cpu_flags & CPU_QUIESCED);


        /*
         * Declare CPU as no longer being READY to process interrupts and
         * wait for them to stop. A CPU that is not READY can no longer
         * participate in x-calls or x-traps.
         */
        cp->cpu_flags &= ~CPU_READY;
        CPUSET_DEL(cpu_ready_set, cpuid);
        membar_sync();

        for (i = 0; i < sanity_limit; i++) {
                if (cp->cpu_intr_actv == 0 &&
                    (cp->cpu_thread == cp->cpu_idle_thread ||
                    cp->cpu_thread == cp->cpu_startup_thread)) {
                        found_intr = 0;
                        break;
                }
                DELAY(1);
        }

        if (found_intr) {

                if (cp->cpu_intr_actv) {
                        cmn_err(CE_PANIC, "%s: cpu_intr_actv != 0", f);
                } else if (cp->cpu_thread != cp->cpu_idle_thread &&
                    cp->cpu_thread != cp->cpu_startup_thread) {
                        cmn_err(CE_PANIC, "%s: CPU %d is not quiesced",
                            f, cpuid);
                }

        }
}

/*
 * Start CPU on user request.
 */
/* ARGSUSED */
int
mp_cpu_start(struct cpu *cp)
{
        ASSERT(MUTEX_HELD(&cpu_lock));
        /*
         * Platforms that use CPU signatures require the signature
         * block update to indicate that this CPU is in the OS now.
         */
        CPU_SIGNATURE(OS_SIG, SIGST_RUN, SIGSUBST_NULL, cp->cpu_id);

        cmp_error_resteer(cp->cpu_id);

        return (0);                     /* nothing special to do on this arch */
}

/*
 * Stop CPU on user request.
 */
/* ARGSUSED */
int
mp_cpu_stop(struct cpu *cp)
{
        ASSERT(MUTEX_HELD(&cpu_lock));

        cmp_error_resteer(cp->cpu_id);

        /*
         * Platforms that use CPU signatures require the signature
         * block update to indicate that this CPU is offlined now.
         */
        CPU_SIGNATURE(OS_SIG, SIGST_OFFLINE, SIGSUBST_NULL, cp->cpu_id);
        return (0);                     /* nothing special to do on this arch */
}

/*
 * Power on CPU.
 */
int
mp_cpu_poweron(struct cpu *cp)
{
        ASSERT(MUTEX_HELD(&cpu_lock));
        if (&plat_cpu_poweron)
                return (plat_cpu_poweron(cp));  /* platform-dependent hook */

        return (ENOTSUP);
}

/*
 * Power off CPU.
 */
int
mp_cpu_poweroff(struct cpu *cp)
{
        ASSERT(MUTEX_HELD(&cpu_lock));
        if (&plat_cpu_poweroff)
                return (plat_cpu_poweroff(cp)); /* platform-dependent hook */

        return (ENOTSUP);
}

void
mp_cpu_faulted_enter(struct cpu *cp)
{
        cpu_faulted_enter(cp);
}

void
mp_cpu_faulted_exit(struct cpu *cp)
{
        cpu_faulted_exit(cp);
}