su.static: link with proto area libs (esp. libc)

[unleashed.git] / kernel / cpr / cpr_main.c

/*
 * 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 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * This module contains the guts of checkpoint-resume mechanism.
 * All code in this module is platform independent.
 */

#include <sys/types.h>
#include <sys/errno.h>
#include <sys/callb.h>
#include <sys/processor.h>
#include <sys/machsystm.h>
#include <sys/clock.h>
#include <sys/vfs.h>
#include <sys/kmem.h>
#include <nfs/lm.h>
#include <sys/systm.h>
#include <sys/cpr.h>
#include <sys/bootconf.h>
#include <sys/cyclic.h>
#include <sys/filio.h>
#include <sys/fs/ufs_filio.h>
#include <sys/epm.h>
#include <sys/modctl.h>
#include <sys/reboot.h>
#include <sys/kdi.h>
#include <sys/promif.h>
#include <sys/srn.h>
#include <sys/cpr_impl.h>

#define PPM(dip) ((dev_info_t *)DEVI(dip)->devi_pm_ppm)

extern struct cpr_terminator cpr_term;

extern int cpr_alloc_statefile(int);
extern void cpr_start_kernel_threads(void);
extern void cpr_abbreviate_devpath(char *, char *);
extern void cpr_convert_promtime(cpr_time_t *);
extern void cpr_send_notice(void);
extern void cpr_set_bitmap_size(void);
extern void cpr_stat_init();
extern void cpr_statef_close(void);
extern void flush_windows(void);
extern void (*srn_signal)(int, int);
extern void init_cpu_syscall(struct cpu *);
extern void i_cpr_pre_resume_cpus();
extern void i_cpr_post_resume_cpus();
extern int cpr_is_ufs(struct vfs *);

extern int pm_powering_down;
extern kmutex_t srn_clone_lock;
extern int srn_inuse;

static int cpr_suspend(int);
static int cpr_resume(int);
static void cpr_suspend_init(int);
#if defined(__x86)
static int cpr_suspend_cpus(void);
static void cpr_resume_cpus(void);
#endif
static int cpr_all_online(void);
static void cpr_restore_offline(void);

cpr_time_t wholecycle_tv;
int cpr_suspend_succeeded;
pfn_t curthreadpfn;
int curthreadremapped;

extern cpuset_t cpu_ready_set;

extern processorid_t i_cpr_bootcpuid(void);
extern cpu_t *i_cpr_bootcpu(void);
extern void tsc_adjust_delta(hrtime_t tdelta);
extern void tsc_resume(void);
extern int tsc_resume_in_cyclic;

/*
 * Set this variable to 1, to have device drivers resume in an
 * uniprocessor environment. This is to allow drivers that assume
 * that they resume on a UP machine to continue to work. Should be
 * deprecated once the broken drivers are fixed
 */
int cpr_resume_uniproc = 0;

/*
 * save or restore abort_enable;  this prevents a drop
 * to kadb or prom during cpr_resume_devices() when
 * there is no kbd present;  see abort_sequence_enter()
 */
static void
cpr_sae(int stash)
{
        static int saved_ae = -1;

        if (stash) {
                saved_ae = abort_enable;
                abort_enable = 0;
        } else if (saved_ae != -1) {
                abort_enable = saved_ae;
                saved_ae = -1;
        }
}


/*
 * The main switching point for cpr, this routine starts the ckpt
 * and state file saving routines; on resume the control is
 * returned back to here and it then calls the resume routine.
 */
int
cpr_main(int sleeptype)
{
        int rc, rc2;
        label_t saveq;
        klwp_t *tlwp = ttolwp(curthread);

        if (sleeptype == CPR_TODISK) {
                if ((rc = cpr_default_setup(1)) != 0)
                        return (rc);
                ASSERT(tlwp);
                saveq = tlwp->lwp_qsav;
        }

        if (sleeptype == CPR_TORAM) {
                rc = cpr_suspend(sleeptype);
                PMD(PMD_SX, ("cpr_suspend rets %x\n", rc))
                if (rc == 0) {
                        int i_cpr_power_down(int sleeptype);

                        /*
                         * From this point on, we should be at a high
                         * spl, interrupts disabled, and all but one
                         * cpu's paused (effectively UP/single threaded).
                         * So this is were we want to put ASSERTS()
                         * to let us know otherwise.
                         */
                        ASSERT(cpus_paused());

                        /*
                         * Now do the work of actually putting this
                         * machine to sleep!
                         */
                        rc = i_cpr_power_down(sleeptype);
                        if (rc == 0) {
                                PMD(PMD_SX, ("back from successful suspend\n"))
                        }
                        /*
                         * We do care about the return value from cpr_resume
                         * at this point, as it will tell us if one of the
                         * resume functions failed (cpr_resume_devices())
                         * However, for this to return and _not_ panic, means
                         * that we must be in one of the test functions.  So
                         * check for that and return an appropriate message.
                         */
                        rc2 = cpr_resume(sleeptype);
                        if (rc2 != 0) {
                                ASSERT(cpr_test_point > 0);
                                cmn_err(CE_NOTE,
                                    "cpr_resume returned non-zero: %d\n", rc2);
                                PMD(PMD_SX, ("cpr_resume rets %x\n", rc2))
                        }
                        ASSERT(!cpus_paused());
                } else {
                        PMD(PMD_SX, ("failed suspend, resuming\n"))
                        rc = cpr_resume(sleeptype);
                }
                return (rc);
        }
        /*
         * Remember where we are for resume after reboot
         */
        if (!setjmp(&tlwp->lwp_qsav)) {
                /*
                 * try to checkpoint the system, if failed return back
                 * to userland, otherwise power off.
                 */
                rc = cpr_suspend(sleeptype);
                if (rc || cpr_reusable_mode) {
                        /*
                         * We don't really want to go down, or
                         * something went wrong in suspend, do what we can
                         * to put the system back to an operable state then
                         * return back to userland.
                         */
                        PMD(PMD_SX, ("failed suspend, resuming\n"))
                        (void) cpr_resume(sleeptype);
                        PMD(PMD_SX, ("back from failed suspend resume\n"))
                }
        } else {
                /*
                 * This is the resumed side of longjmp, restore the previous
                 * longjmp pointer if there is one so this will be transparent
                 * to the world.
                 * This path is only for CPR_TODISK, where we reboot
                 */
                ASSERT(sleeptype == CPR_TODISK);
                tlwp->lwp_qsav = saveq;
                CPR->c_flags &= ~C_SUSPENDING;
                CPR->c_flags |= C_RESUMING;

                /*
                 * resume the system back to the original state
                 */
                rc = cpr_resume(sleeptype);
                PMD(PMD_SX, ("back from successful suspend; resume rets %x\n",
                    rc))
        }

        (void) cpr_default_setup(0);

        return (rc);
}




/*
 * Check if klmmod is loaded and call a lock manager service; if klmmod
 * is not loaded, the services aren't needed and a call would trigger a
 * modload, which would block since another thread would never run.
 */
static void
cpr_lock_mgr(void (*service)(void))
{
        if (mod_find_by_filename(NULL, "misc/klmmod") != NULL)
                (*service)();
}

int
cpr_suspend_cpus(void)
{
        int     ret = 0;
        extern void *i_cpr_save_context(void *arg);

        mutex_enter(&cpu_lock);

        /*
         * the machine could not have booted without a bootcpu
         */
        ASSERT(i_cpr_bootcpu() != NULL);

        /*
         * bring all the offline cpus online
         */
        if ((ret = cpr_all_online())) {
                mutex_exit(&cpu_lock);
                return (ret);
        }

        /*
         * Set the affinity to be the boot processor
         * This is cleared in either cpr_resume_cpus() or cpr_unpause_cpus()
         */
        affinity_set(i_cpr_bootcpuid());

        ASSERT(CPU->cpu_id == 0);

        PMD(PMD_SX, ("curthread running on bootcpu\n"))

        /*
         * pause all other running CPUs and save the CPU state at the sametime
         */
        pause_cpus(NULL, i_cpr_save_context);

        mutex_exit(&cpu_lock);

        return (0);
}

/*
 * Take the system down to a checkpointable state and write
 * the state file, the following are sequentially executed:
 *
 *    - Request all user threads to stop themselves
 *    - push out and invalidate user pages
 *    - bring statefile inode incore to prevent a miss later
 *    - request all daemons to stop
 *    - check and make sure all threads are stopped
 *    - sync the file system
 *    - suspend all devices
 *    - block intrpts
 *    - dump system state and memory to state file
 *    - SPARC code will not be called with CPR_TORAM, caller filters
 */
static int
cpr_suspend(int sleeptype)
{
        int     rc = 0;
        int     skt_rc = 0;

        PMD(PMD_SX, ("cpr_suspend %x\n", sleeptype))
        cpr_set_substate(C_ST_SUSPEND_BEGIN);

        cpr_suspend_init(sleeptype);

        cpr_save_time();

        cpr_tod_get(&wholecycle_tv);
        CPR_STAT_EVENT_START("Suspend Total");

        i_cpr_alloc_cpus();


        PMD(PMD_SX, ("cpr_suspend: stop scans\n"))
        /* Stop PM scans ASAP */
        (void) callb_execute_class(CB_CL_CPR_PM, CB_CODE_CPR_CHKPT);

        pm_dispatch_to_dep_thread(PM_DEP_WK_CPR_SUSPEND,
            NULL, NULL, PM_DEP_WAIT, NULL, 0);

        /*
         * Ask Xorg to suspend the frame buffer, and wait for it to happen
         */
        mutex_enter(&srn_clone_lock);
        if (srn_signal) {
                PMD(PMD_SX, ("cpr_suspend: (*srn_signal)(..., "
                    "SRN_SUSPEND_REQ)\n"))
                srn_inuse = 1;  /* because *(srn_signal) cv_waits */
                (*srn_signal)(SRN_TYPE_APM, SRN_SUSPEND_REQ);
                srn_inuse = 0;
        } else {
                PMD(PMD_SX, ("cpr_suspend: srn_signal NULL\n"))
        }
        mutex_exit(&srn_clone_lock);

        /*
         * Ask the user threads to stop by themselves, but
         * if they don't or can't after 3 retries, we give up on CPR.
         * The 3 retry is not a random number because 2 is possible if
         * a thread has been forked before the parent thread is stopped.
         */
        CPR_DEBUG(CPR_DEBUG1, "\nstopping user threads...");
        CPR_STAT_EVENT_START("  stop users");
        cpr_set_substate(C_ST_STOP_USER_THREADS);
        PMD(PMD_SX, ("cpr_suspend: stop user threads\n"))
        if (rc = cpr_stop_user_threads())
                return (rc);
        CPR_STAT_EVENT_END("  stop users");
        CPR_DEBUG(CPR_DEBUG1, "done\n");

        PMD(PMD_SX, ("cpr_suspend: save direct levels\n"))
        pm_save_direct_levels();

        /*
         * User threads are stopped.  We will start communicating with the
         * user via prom_printf (some debug output may have already happened)
         * so let anybody who cares know about this (bug 4096122)
         */
        (void) callb_execute_class(CB_CL_CPR_PROMPRINTF, CB_CODE_CPR_CHKPT);

        PMD(PMD_SX, ("cpr_suspend: send notice\n"))
#ifndef DEBUG
        cpr_send_notice();
        if (cpr_debug)
                prom_printf("\n");
#endif

        PMD(PMD_SX, ("cpr_suspend: POST USER callback\n"))
        (void) callb_execute_class(CB_CL_CPR_POST_USER, CB_CODE_CPR_CHKPT);

        /*
         * Reattach any drivers which originally exported the
         * no-involuntary-power-cycles property.  We need to do this before
         * stopping kernel threads because modload is implemented using
         * a kernel thread.
         */
        cpr_set_substate(C_ST_PM_REATTACH_NOINVOL);
        PMD(PMD_SX, ("cpr_suspend: reattach noinvol\n"))
        if (!pm_reattach_noinvol())
                return (ENXIO);



        /*
         * Hooks needed by lock manager prior to suspending.
         * Refer to code for more comments.
         */
        PMD(PMD_SX, ("cpr_suspend: lock mgr\n"))
        cpr_lock_mgr(lm_cprsuspend);

        /*
         * Now suspend all the devices
         */
        CPR_STAT_EVENT_START("  stop drivers");
        CPR_DEBUG(CPR_DEBUG1, "suspending drivers...");
        cpr_set_substate(C_ST_SUSPEND_DEVICES);
        pm_powering_down = 1;
        PMD(PMD_SX, ("cpr_suspend: suspending devices\n"))
        rc = cpr_suspend_devices(ddi_root_node());
        pm_powering_down = 0;
        if (rc)
                return (rc);
        CPR_DEBUG(CPR_DEBUG1, "done\n");
        CPR_STAT_EVENT_END("  stop drivers");

        /*
         * Stop all daemon activities
         */
        cpr_set_substate(C_ST_STOP_KERNEL_THREADS);
        PMD(PMD_SX, ("cpr_suspend: stopping kernel threads\n"))
        if (skt_rc = cpr_stop_kernel_threads())
                return (skt_rc);

        PMD(PMD_SX, ("cpr_suspend: POST KERNEL callback\n"))
        (void) callb_execute_class(CB_CL_CPR_POST_KERNEL, CB_CODE_CPR_CHKPT);

        PMD(PMD_SX, ("cpr_suspend: reattach noinvol fini\n"))
        pm_reattach_noinvol_fini();

        cpr_sae(1);

        PMD(PMD_SX, ("cpr_suspend: CPR CALLOUT callback\n"))
        (void) callb_execute_class(CB_CL_CPR_CALLOUT, CB_CODE_CPR_CHKPT);

        if (sleeptype == CPR_TODISK) {
                /*
                 * It's safer to do tod_get before we disable all intr.
                 */
                CPR_STAT_EVENT_START("  write statefile");
        }

        /*
         * it's time to ignore the outside world, stop the real time
         * clock and disable any further intrpt activity.
         */
        PMD(PMD_SX, ("cpr_suspend: handle xc\n"))
        i_cpr_handle_xc(1);     /* turn it on to disable xc assertion */

        mutex_enter(&cpu_lock);
        PMD(PMD_SX, ("cpr_suspend: cyclic suspend\n"))
        cyclic_suspend();
        mutex_exit(&cpu_lock);

        /*
         * Due to the different methods of resuming the system between
         * CPR_TODISK (boot cprboot on SPARC, which reloads kernel image)
         * and CPR_TORAM (restart via reset into existing kernel image)
         * cpus are not suspended and restored in the SPARC case, since it
         * is necessary to restart the cpus and pause them before restoring
         * the OBP image
         */

#if defined(__x86)

        /* pause aux cpus */
        PMD(PMD_SX, ("pause aux cpus\n"))

        cpr_set_substate(C_ST_MP_PAUSED);

        if ((rc = cpr_suspend_cpus()) != 0)
                return (rc);
#endif

        PMD(PMD_SX, ("cpr_suspend: stop intr\n"))
        i_cpr_stop_intr();
        CPR_DEBUG(CPR_DEBUG1, "interrupt is stopped\n");

        /*
         * Since we will now disable the mechanism that causes prom_printfs
         * to power up (if needed) the console fb/monitor, we assert that
         * it must be up now.
         */
        ASSERT(pm_cfb_is_up());
        PMD(PMD_SX, ("cpr_suspend: prom suspend prepost\n"))
        prom_suspend_prepost();


        /*
         * For S3, we're done
         */
        if (sleeptype == CPR_TORAM) {
                PMD(PMD_SX, ("cpr_suspend rets %x\n", rc))
                cpr_set_substate(C_ST_NODUMP);
                return (rc);
        }
        PMD(PMD_SX, ("cpr_suspend: return %d\n", rc))
        return (rc);
}

void
cpr_resume_cpus(void)
{
        /*
         * this is a cut down version of start_other_cpus()
         * just do the initialization to wake the other cpus
         */

#if defined(__x86)
        /*
         * Initialize our syscall handlers
         */
        init_cpu_syscall(CPU);

#endif

        i_cpr_pre_resume_cpus();

        /*
         * Restart the paused cpus
         */
        mutex_enter(&cpu_lock);
        start_cpus();
        mutex_exit(&cpu_lock);

        i_cpr_post_resume_cpus();

        mutex_enter(&cpu_lock);
        /*
         * clear the affinity set in cpr_suspend_cpus()
         */
        affinity_clear();

        /*
         * offline all the cpus that were brought online during suspend
         */
        cpr_restore_offline();

        mutex_exit(&cpu_lock);
}

void
cpr_unpause_cpus(void)
{
        /*
         * Now restore the system back to what it was before we suspended
         */

        PMD(PMD_SX, ("cpr_unpause_cpus: restoring system\n"))

        mutex_enter(&cpu_lock);
        /*
         * Restart the paused cpus
         */
        start_cpus();

        /*
         * clear the affinity set in cpr_suspend_cpus()
         */
        affinity_clear();

        /*
         * offline all the cpus that were brought online during suspend
         */
        cpr_restore_offline();

        mutex_exit(&cpu_lock);
}

/*
 * Bring the system back up from a checkpoint, at this point
 * the VM has been minimally restored by boot, the following
 * are executed sequentially:
 *
 *    - machdep setup and enable interrupts (mp startup if it's mp)
 *    - resume all devices
 *    - restart daemons
 *    - put all threads back on run queue
 */
static int
cpr_resume(int sleeptype)
{
        cpr_time_t pwron_tv, *ctp;
        char *str;
        int rc = 0;

        /*
         * The following switch is used to resume the system
         * that was suspended to a different level.
         */
        CPR_DEBUG(CPR_DEBUG1, "\nEntering cpr_resume...\n");
        PMD(PMD_SX, ("cpr_resume %x\n", sleeptype))

        /*
         * Note:
         *
         * The rollback labels rb_xyz do not represent the cpr resume
         * state when event 'xyz' has happened. Instead they represent
         * the state during cpr suspend when event 'xyz' was being
         * entered (and where cpr suspend failed). The actual call that
         * failed may also need to be partially rolled back, since they
         * aren't atomic in most cases.  In other words, rb_xyz means
         * "roll back all cpr suspend events that happened before 'xyz',
         * and the one that caused the failure, if necessary."
         */
        switch (CPR->c_substate) {

        case C_ST_NODUMP:
                PMD(PMD_SX, ("cpr_resume: NODUMP\n"))
                goto rb_nodump;

        case C_ST_STOP_KERNEL_THREADS:
                PMD(PMD_SX, ("cpr_resume: STOP_KERNEL_THREADS\n"))
                goto rb_stop_kernel_threads;

        case C_ST_SUSPEND_DEVICES:
                PMD(PMD_SX, ("cpr_resume: SUSPEND_DEVICES\n"))
                goto rb_suspend_devices;


        case C_ST_PM_REATTACH_NOINVOL:
                PMD(PMD_SX, ("cpr_resume: REATTACH_NOINVOL\n"))
                goto rb_pm_reattach_noinvol;

        case C_ST_STOP_USER_THREADS:
                PMD(PMD_SX, ("cpr_resume: STOP_USER_THREADS\n"))
                goto rb_stop_user_threads;


#if defined(__x86)
        case C_ST_MP_PAUSED:
                PMD(PMD_SX, ("cpr_resume: MP_PAUSED\n"))
                goto rb_mp_paused;
#endif


        default:
                PMD(PMD_SX, ("cpr_resume: others\n"))
                goto rb_others;
        }

rb_all:
        /*
         * perform platform-dependent initialization
         */
        if (cpr_suspend_succeeded)
                i_cpr_machdep_setup();

        /*
         * system did not really go down if we jump here
         */
rb_dump:
        /*
         * IMPORTANT:  SENSITIVE RESUME SEQUENCE
         *
         * DO NOT ADD ANY INITIALIZATION STEP BEFORE THIS POINT!!
         */
rb_nodump:
        /*
         * If we did suspend to RAM, we didn't generate a dump
         */
        PMD(PMD_SX, ("cpr_resume: CPR DMA callback\n"))
        (void) callb_execute_class(CB_CL_CPR_DMA, CB_CODE_CPR_RESUME);
        if (cpr_suspend_succeeded) {
                PMD(PMD_SX, ("cpr_resume: CPR RPC callback\n"))
                (void) callb_execute_class(CB_CL_CPR_RPC, CB_CODE_CPR_RESUME);
        }

        prom_resume_prepost();
        /*
         * Need to sync the software clock with the hardware clock.
         * On Sparc, this occurs in the sparc-specific cbe.  However
         * on x86 this needs to be handled _before_ we bring other cpu's
         * back online.  So we call a resume function in timestamp.c
         */
        if (tsc_resume_in_cyclic == 0)
                tsc_resume();




#if defined(__x86)
rb_mp_paused:
        PT(PT_RMPO);
        PMD(PMD_SX, ("resume aux cpus\n"))

        if (cpr_suspend_succeeded) {
                cpr_resume_cpus();
        } else {
                cpr_unpause_cpus();
        }
#endif

        /*
         * let the tmp callout catch up.
         */
        PMD(PMD_SX, ("cpr_resume: CPR CALLOUT callback\n"))
        (void) callb_execute_class(CB_CL_CPR_CALLOUT, CB_CODE_CPR_RESUME);

        i_cpr_enable_intr();

        mutex_enter(&cpu_lock);
        PMD(PMD_SX, ("cpr_resume: cyclic resume\n"))
        cyclic_resume();
        mutex_exit(&cpu_lock);

        PMD(PMD_SX, ("cpr_resume: handle xc\n"))
        i_cpr_handle_xc(0);     /* turn it off to allow xc assertion */

        PMD(PMD_SX, ("cpr_resume: CPR POST KERNEL callback\n"))
        (void) callb_execute_class(CB_CL_CPR_POST_KERNEL, CB_CODE_CPR_RESUME);

        /*
         * statistics gathering
         */
        if (cpr_suspend_succeeded) {
                /*
                 * Prevent false alarm in tod_validate() due to tod
                 * value change between suspend and resume
                 */
                cpr_tod_status_set(TOD_CPR_RESUME_DONE);

                cpr_convert_promtime(&pwron_tv);

                ctp = &cpr_term.tm_shutdown;
                if (sleeptype == CPR_TODISK)
                        CPR_STAT_EVENT_END_TMZ("  write statefile", ctp);
                CPR_STAT_EVENT_END_TMZ("Suspend Total", ctp);

                CPR_STAT_EVENT_START_TMZ("Resume Total", &pwron_tv);

                str = "  prom time";
                CPR_STAT_EVENT_START_TMZ(str, &pwron_tv);
                ctp = &cpr_term.tm_cprboot_start;
                CPR_STAT_EVENT_END_TMZ(str, ctp);

                str = "  read statefile";
                CPR_STAT_EVENT_START_TMZ(str, ctp);
                ctp = &cpr_term.tm_cprboot_end;
                CPR_STAT_EVENT_END_TMZ(str, ctp);
        }

rb_stop_kernel_threads:
        /*
         * Put all threads back to where they belong; get the kernel
         * daemons straightened up too. Note that the callback table
         * locked during cpr_stop_kernel_threads() is released only
         * in cpr_start_kernel_threads(). Ensure modunloading is
         * disabled before starting kernel threads, we don't want
         * modunload thread to start changing device tree underneath.
         */
        PMD(PMD_SX, ("cpr_resume: modunload disable\n"))
        modunload_disable();
        PMD(PMD_SX, ("cpr_resume: start kernel threads\n"))
        cpr_start_kernel_threads();

rb_suspend_devices:
        CPR_DEBUG(CPR_DEBUG1, "resuming devices...");
        CPR_STAT_EVENT_START("  start drivers");

        PMD(PMD_SX,
            ("cpr_resume: rb_suspend_devices: cpr_resume_uniproc = %d\n",
            cpr_resume_uniproc))

#if defined(__x86)
        /*
         * If cpr_resume_uniproc is set, then pause all the other cpus
         * apart from the current cpu, so that broken drivers that think
         * that they are on a uniprocessor machine will resume
         */
        if (cpr_resume_uniproc) {
                mutex_enter(&cpu_lock);
                pause_cpus(NULL, NULL);
                mutex_exit(&cpu_lock);
        }
#endif

        /*
         * The policy here is to continue resume everything we can if we did
         * not successfully finish suspend; and panic if we are coming back
         * from a fully suspended system.
         */
        PMD(PMD_SX, ("cpr_resume: resume devices\n"))
        rc = cpr_resume_devices(ddi_root_node(), 0);

        cpr_sae(0);

        str = "Failed to resume one or more devices.";

        if (rc) {
                if (CPR->c_substate == C_ST_DUMP ||
                    (sleeptype == CPR_TORAM &&
                    CPR->c_substate == C_ST_NODUMP)) {
                        if (cpr_test_point == FORCE_SUSPEND_TO_RAM) {
                                PMD(PMD_SX, ("cpr_resume: resume device "
                                    "warn\n"))
                                cpr_err(CE_WARN, str);
                        } else {
                                PMD(PMD_SX, ("cpr_resume: resume device "
                                    "panic\n"))
                                cpr_err(CE_PANIC, str);
                        }
                } else {
                        PMD(PMD_SX, ("cpr_resume: resume device warn\n"))
                        cpr_err(CE_WARN, str);
                }
        }

        CPR_STAT_EVENT_END("  start drivers");
        CPR_DEBUG(CPR_DEBUG1, "done\n");

#if defined(__x86)
        /*
         * If cpr_resume_uniproc is set, then unpause all the processors
         * that were paused before resuming the drivers
         */
        if (cpr_resume_uniproc) {
                mutex_enter(&cpu_lock);
                start_cpus();
                mutex_exit(&cpu_lock);
        }
#endif

        /*
         * If we had disabled modunloading in this cpr resume cycle (i.e. we
         * resumed from a state earlier than C_ST_SUSPEND_DEVICES), re-enable
         * modunloading now.
         */
        if (CPR->c_substate != C_ST_SUSPEND_DEVICES) {
                PMD(PMD_SX, ("cpr_resume: modload enable\n"))
                modunload_enable();
        }

        /*
         * Hooks needed by lock manager prior to resuming.
         * Refer to code for more comments.
         */
        PMD(PMD_SX, ("cpr_resume: lock mgr\n"))
        cpr_lock_mgr(lm_cprresume);


rb_pm_reattach_noinvol:
        /*
         * When pm_reattach_noinvol() succeeds, modunload_thread will
         * remain disabled until after cpr suspend passes the
         * C_ST_STOP_KERNEL_THREADS state. If any failure happens before
         * cpr suspend reaches this state, we'll need to enable modunload
         * thread during rollback.
         */
        if (CPR->c_substate == C_ST_DISABLE_UFS_LOGGING ||
            CPR->c_substate == C_ST_STATEF_ALLOC ||
            CPR->c_substate == C_ST_SUSPEND_DEVICES ||
            CPR->c_substate == C_ST_STOP_KERNEL_THREADS) {
                PMD(PMD_SX, ("cpr_resume: reattach noinvol fini\n"))
                pm_reattach_noinvol_fini();
        }

        PMD(PMD_SX, ("cpr_resume: CPR POST USER callback\n"))
        (void) callb_execute_class(CB_CL_CPR_POST_USER, CB_CODE_CPR_RESUME);
        PMD(PMD_SX, ("cpr_resume: CPR PROMPRINTF callback\n"))
        (void) callb_execute_class(CB_CL_CPR_PROMPRINTF, CB_CODE_CPR_RESUME);

        PMD(PMD_SX, ("cpr_resume: restore direct levels\n"))
        pm_restore_direct_levels();

rb_stop_user_threads:
        CPR_DEBUG(CPR_DEBUG1, "starting user threads...");
        PMD(PMD_SX, ("cpr_resume: starting user threads\n"))
        cpr_start_user_threads();
        CPR_DEBUG(CPR_DEBUG1, "done\n");
        /*
         * Ask Xorg to resume the frame buffer, and wait for it to happen
         */
        mutex_enter(&srn_clone_lock);
        if (srn_signal) {
                PMD(PMD_SX, ("cpr_suspend: (*srn_signal)(..., "
                    "SRN_NORMAL_RESUME)\n"))
                srn_inuse = 1;          /* because (*srn_signal) cv_waits */
                (*srn_signal)(SRN_TYPE_APM, SRN_NORMAL_RESUME);
                srn_inuse = 0;
        } else {
                PMD(PMD_SX, ("cpr_suspend: srn_signal NULL\n"))
        }
        mutex_exit(&srn_clone_lock);


rb_others:
        PMD(PMD_SX, ("cpr_resume: dep thread\n"))
        pm_dispatch_to_dep_thread(PM_DEP_WK_CPR_RESUME, NULL, NULL,
            PM_DEP_WAIT, NULL, 0);

        PMD(PMD_SX, ("cpr_resume: CPR PM callback\n"))
        (void) callb_execute_class(CB_CL_CPR_PM, CB_CODE_CPR_RESUME);

        if (cpr_suspend_succeeded) {
                cpr_stat_record_events();
        }


        i_cpr_free_cpus();
        CPR_DEBUG(CPR_DEBUG1, "Sending SIGTHAW...");
        PMD(PMD_SX, ("cpr_resume: SIGTHAW\n"))
        cpr_signal_user(SIGTHAW);
        CPR_DEBUG(CPR_DEBUG1, "done\n");

        CPR_STAT_EVENT_END("Resume Total");

        CPR_STAT_EVENT_START_TMZ("WHOLE CYCLE", &wholecycle_tv);
        CPR_STAT_EVENT_END("WHOLE CYCLE");

        if (cpr_debug & CPR_DEBUG1)
                cmn_err(CE_CONT, "\nThe system is back where you left!\n");

        CPR_STAT_EVENT_START("POST CPR DELAY");

#ifdef CPR_STAT
        ctp = &cpr_term.tm_shutdown;
        CPR_STAT_EVENT_START_TMZ("PWROFF TIME", ctp);
        CPR_STAT_EVENT_END_TMZ("PWROFF TIME", &pwron_tv);

        CPR_STAT_EVENT_PRINT();
#endif /* CPR_STAT */

        PMD(PMD_SX, ("cpr_resume returns %x\n", rc))
        return (rc);
}

static void
cpr_suspend_init(int sleeptype)
{
        cpr_time_t *ctp;

        cpr_stat_init();

        /*
         * If cpr_suspend() failed before cpr_dump() gets a chance
         * to reinitialize the terminator of the statefile,
         * the values of the old terminator will still linger around.
         * Since the terminator contains information that we need to
         * decide whether suspend succeeded or not, we need to
         * reinitialize it as early as possible.
         */
        cpr_term.real_statef_size = 0;
        ctp = &cpr_term.tm_shutdown;
        bzero(ctp, sizeof (*ctp));
        ctp = &cpr_term.tm_cprboot_start;
        bzero(ctp, sizeof (*ctp));
        ctp = &cpr_term.tm_cprboot_end;
        bzero(ctp, sizeof (*ctp));

        if (sleeptype == CPR_TODISK) {
                /*
                 * Lookup the physical address of our thread structure.
                 * This should never be invalid and the entire thread structure
                 * is expected to reside within the same pfn.
                 */
                curthreadpfn = hat_getpfnum(kas.a_hat, (caddr_t)curthread);
                ASSERT(curthreadpfn != PFN_INVALID);
                ASSERT(curthreadpfn == hat_getpfnum(kas.a_hat,
                    (caddr_t)curthread + sizeof (kthread_t) - 1));
        }

        cpr_suspend_succeeded = 0;
}

/*
 * bring all the offline cpus online
 */
static int
cpr_all_online(void)
{
        int     rc = 0;


        cpu_t   *cp;

        ASSERT(MUTEX_HELD(&cpu_lock));

        cp = cpu_list;
        do {
                cp->cpu_cpr_flags &= ~CPU_CPR_ONLINE;
                if (!CPU_ACTIVE(cp)) {
                        if ((rc = cpu_online(cp)) != 0)
                                break;
                        CPU_SET_CPR_FLAGS(cp, CPU_CPR_ONLINE);
                }
        } while ((cp = cp->cpu_next) != cpu_list);

        if (rc) {
                /*
                 * an online operation failed so offline the cpus
                 * that were onlined above to restore the system
                 * to its original state
                 */
                cpr_restore_offline();
        }
        return (rc);
}

/*
 * offline all the cpus that were brought online by cpr_all_online()
 */
static void
cpr_restore_offline(void)
{


        cpu_t   *cp;
        int     rc = 0;

        ASSERT(MUTEX_HELD(&cpu_lock));

        cp = cpu_list;
        do {
                if (CPU_CPR_IS_ONLINE(cp)) {
                        rc =  cpu_offline(cp, 0);
                        /*
                         * this offline should work, since the cpu was
                         * offline originally and was successfully onlined
                         * by cpr_all_online()
                         */
                        ASSERT(rc == 0);
                        cp->cpu_cpr_flags &= ~CPU_CPR_ONLINE;
                }
        } while ((cp = cp->cpu_next) != cpu_list);


}