/*
 * Copyright (c) 2007 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cpumask.h>
#include <sys/interrupt.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/memrange.h>
#include <sys/tls.h>
#include <sys/types.h>

#include <vm/vm_extern.h>
#include <vm/vm_kern.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>

#include <sys/mplock2.h>
#include <sys/thread2.h>

#include <machine/cpu.h>
#include <machine/cpufunc.h>
#include <machine/globaldata.h>
#include <machine/md_var.h>
#include <machine/pmap.h>
#include <machine/smp.h>
#include <machine/tls.h>
#include <machine/param.h>

#include <unistd.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>

extern pt_entry_t *KPTphys;

volatile cpumask_t stopped_cpus;
/* which cpus are ready for IPIs etc? */
cpumask_t       smp_active_mask = CPUMASK_INITIALIZER_ONLYONE;
static int      boot_address;
/* which cpus have been started */
static cpumask_t smp_startup_mask = CPUMASK_INITIALIZER_ONLYONE;
static int  mp_finish;

/* Local data for detecting CPU TOPOLOGY */
static int core_bits = 0;
static int logical_CPU_bits = 0;

/* function prototypes XXX these should go elsewhere */
void bootstrap_idle(void);
void single_cpu_ipi(int, int, int);
void selected_cpu_ipi(cpumask_t, int, int);
#if 0
void ipi_handler(int);
#endif

pt_entry_t *SMPpt;

/* AP uses this during bootstrap.  Do not staticize.  */
char *bootSTK;
static int bootAP;


/* XXX these need to go into the appropriate header file */
static int start_all_aps(u_int);
void init_secondary(void);
void *start_ap(void *);

/*
 * Get SMP fully working before we start initializing devices.
 */
static
void
ap_finish(void)
{
        mp_finish = 1;
        if (bootverbose)
                kprintf("Finish MP startup\n");

        /* build our map of 'other' CPUs */
        mycpu->gd_other_cpus = smp_startup_mask;
        CPUMASK_NANDBIT(mycpu->gd_other_cpus, mycpu->gd_cpuid);

        /*
         * Let the other cpu's finish initializing and build their map
         * of 'other' CPUs.
         */
        rel_mplock();
        while (CPUMASK_CMPMASKNEQ(smp_active_mask,smp_startup_mask)) {
                DELAY(100000);
                cpu_lfence();
        }

        while (try_mplock() == 0)
                DELAY(100000);
        if (bootverbose)
                kprintf("Active CPU Mask: %08lx\n",
                        (long)CPUMASK_LOWMASK(smp_active_mask));
}

SYSINIT(finishsmp, SI_BOOT2_FINISH_SMP, SI_ORDER_FIRST, ap_finish, NULL);

void *
start_ap(void *arg __unused)
{
        init_secondary();
        setrealcpu();
        bootstrap_idle();

        return(NULL); /* NOTREACHED */
}

/* storage for AP thread IDs */
pthread_t ap_tids[MAXCPU];

int naps;

void
mp_start(void)
{
        size_t ipiq_size;
        int shift;

        ncpus = optcpus;
        naps = ncpus - 1;

        for (shift = 0; (1 << shift) <= ncpus; ++shift)
                ;
        --shift;

        /* ncpus_fit -- ncpus rounded up to the nearest power of 2 */
        if ((1 << shift) < ncpus)
                ++shift;
        ncpus_fit = 1 << shift;
        ncpus_fit_mask = ncpus_fit - 1;

        malloc_reinit_ncpus();

        /*
         * cpu0 initialization
         */
        ipiq_size = sizeof(struct lwkt_ipiq) * ncpus;
        mycpu->gd_ipiq = (void *)kmem_alloc(kernel_map, ipiq_size,
                                            VM_SUBSYS_IPIQ);
        bzero(mycpu->gd_ipiq, ipiq_size);

        /* initialize arc4random. */
        arc4_init_pcpu(0);

        /*
         * cpu 1-(n-1)
         */
        start_all_aps(boot_address);

}

void
mp_announce(void)
{
        int x;

        kprintf("DragonFly/MP: Multiprocessor\n");
        kprintf(" cpu0 (BSP)\n");

        for (x = 1; x <= naps; ++x)
                kprintf(" cpu%d (AP)\n", x);
}

void
cpu_send_ipiq(int dcpu)
{
        if (CPUMASK_TESTBIT(smp_active_mask, dcpu)) {
                if (pthread_kill(ap_tids[dcpu], SIGUSR1) != 0)
                        panic("pthread_kill failed in cpu_send_ipiq");
        }
#if 0
        panic("XXX cpu_send_ipiq()");
#endif
}

void
single_cpu_ipi(int cpu, int vector, int delivery_mode)
{
        kprintf("XXX single_cpu_ipi\n");
}

void
selected_cpu_ipi(cpumask_t target, int vector, int delivery_mode)
{
        crit_enter();
        while (CPUMASK_TESTNZERO(target)) {
                int n = BSFCPUMASK(target);
                CPUMASK_NANDBIT(target, n);
                single_cpu_ipi(n, vector, delivery_mode);
        }
        crit_exit();
}

int
stop_cpus(cpumask_t map)
{
        CPUMASK_ANDMASK(map, smp_active_mask);

        crit_enter();
        while (CPUMASK_TESTNZERO(map)) {
                int n = BSFCPUMASK(map);
                CPUMASK_NANDBIT(map, n);
                ATOMIC_CPUMASK_ORBIT(stopped_cpus, n);
                if (pthread_kill(ap_tids[n], SIGXCPU) != 0)
                        panic("stop_cpus: pthread_kill failed");
        }
        crit_exit();
#if 0
        panic("XXX stop_cpus()");
#endif

        return(1);
}

int
restart_cpus(cpumask_t map)
{
        CPUMASK_ANDMASK(map, smp_active_mask);

        crit_enter();
        while (CPUMASK_TESTNZERO(map)) {
                int n = BSFCPUMASK(map);
                CPUMASK_NANDBIT(map, n);
                ATOMIC_CPUMASK_NANDBIT(stopped_cpus, n);
                if (pthread_kill(ap_tids[n], SIGXCPU) != 0)
                        panic("restart_cpus: pthread_kill failed");
        }
        crit_exit();
#if 0
        panic("XXX restart_cpus()");
#endif

        return(1);
}
void
ap_init(void)
{
        /*
         * Adjust smp_startup_mask to signal the BSP that we have started
         * up successfully.  Note that we do not yet hold the BGL.  The BSP
         * is waiting for our signal.
         *
         * We can't set our bit in smp_active_mask yet because we are holding
         * interrupts physically disabled and remote cpus could deadlock
         * trying to send us an IPI.
         */
        ATOMIC_CPUMASK_ORBIT(smp_startup_mask, mycpu->gd_cpuid);
        cpu_mfence();

        /*
         * Interlock for finalization.  Wait until mp_finish is non-zero,
         * then get the MP lock.
         *
         * Note: We are in a critical section.
         *
         * Note: we are the idle thread, we can only spin.
         *
         * Note: The load fence is memory volatile and prevents the compiler
         * from improperly caching mp_finish, and the cpu from improperly
         * caching it.
         */

        while (mp_finish == 0) {
                cpu_lfence();
                DELAY(500000);
        }
        while (try_mplock() == 0)
                DELAY(100000);

        /* BSP may have changed PTD while we're waiting for the lock */
        cpu_invltlb();

        /* Build our map of 'other' CPUs. */
        mycpu->gd_other_cpus = smp_startup_mask;
        CPUMASK_NANDBIT(mycpu->gd_other_cpus, mycpu->gd_cpuid);

        kprintf("SMP: AP CPU #%d Launched!\n", mycpu->gd_cpuid);


        /* Set memory range attributes for this CPU to match the BSP */
        mem_range_AP_init();
        /*
         * Once we go active we must process any IPIQ messages that may
         * have been queued, because no actual IPI will occur until we
         * set our bit in the smp_active_mask.  If we don't the IPI
         * message interlock could be left set which would also prevent
         * further IPIs.
         *
         * The idle loop doesn't expect the BGL to be held and while
         * lwkt_switch() normally cleans things up this is a special case
         * because we returning almost directly into the idle loop.
         *
         * The idle thread is never placed on the runq, make sure
         * nothing we've done put it there.
         */
        KKASSERT(get_mplock_count(curthread) == 1);
        ATOMIC_CPUMASK_ORBIT(smp_active_mask, mycpu->gd_cpuid);

        mdcpu->gd_fpending = 0;
        mdcpu->gd_ipending = 0;
        initclocks_pcpu();      /* clock interrupts (via IPIs) */

        /*
         * Since we may have cleaned up the interrupt triggers, manually
         * process any pending IPIs before exiting our critical section.
         * Once the critical section has exited, normal interrupt processing
         * may occur.
         */
        atomic_swap_int(&mycpu->gd_npoll, 0);
        lwkt_process_ipiq();

        /*
         * Releasing the mp lock lets the BSP finish up the SMP init
         */
        rel_mplock();
        KKASSERT((curthread->td_flags & TDF_RUNQ) == 0);
}

void
init_secondary(void)
{
        int     myid = bootAP;
        struct mdglobaldata *md;
        struct privatespace *ps;

        ps = &CPU_prvspace[myid];

        KKASSERT(ps->mdglobaldata.mi.gd_prvspace == ps);

        /*
         * Setup the %gs for cpu #n.  The mycpu macro works after this
         * point.  Note that %fs is used by pthreads.
         */
        tls_set_gs(&CPU_prvspace[myid], sizeof(struct privatespace));

        md = mdcpu;     /* loaded through %gs:0 (mdglobaldata.mi.gd_prvspace)*/

        /* JG */
        md->gd_common_tss.tss_rsp0 = 0; /* not used until after switch */
        //md->gd_common_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
        //md->gd_common_tss.tss_ioopt = (sizeof md->gd_common_tss) << 16;

        /*
         * Set to a known state:
         * Set by mpboot.s: CR0_PG, CR0_PE
         * Set by cpu_setregs: CR0_NE, CR0_MP, CR0_TS, CR0_WP, CR0_AM
         */
}

static int
start_all_aps(u_int boot_addr)
{
        int x, i;
        struct mdglobaldata *gd;
        struct privatespace *ps;
        vm_page_t m;
        vm_offset_t va;
        pthread_attr_t attr;
        size_t ipiq_size;
#if 0
        struct lwp_params params;
#endif

        /*
         * needed for ipis to initial thread
         * FIXME: rename ap_tids?
         */
        ap_tids[0] = pthread_self();
        pthread_attr_init(&attr);

        vm_object_hold(kernel_object);
        for (x = 1; x <= naps; ++x) {
                /* Allocate space for the CPU's private space. */
                for (i = 0; i < sizeof(struct mdglobaldata); i += PAGE_SIZE) {
                        va =(vm_offset_t)&CPU_prvspace[x].mdglobaldata + i;
                        m = vm_page_alloc(kernel_object, va, VM_ALLOC_SYSTEM);
                        pmap_kenter_quick(va, m->phys_addr);
                }

                for (i = 0; i < sizeof(CPU_prvspace[x].idlestack); i += PAGE_SIZE) {
                        va =(vm_offset_t)&CPU_prvspace[x].idlestack + i;
                        m = vm_page_alloc(kernel_object, va, VM_ALLOC_SYSTEM);
                        pmap_kenter_quick(va, m->phys_addr);
                }

                gd = &CPU_prvspace[x].mdglobaldata;     /* official location */
                bzero(gd, sizeof(*gd));
                gd->mi.gd_prvspace = ps = &CPU_prvspace[x];

                /* prime data page for it to use */
                mi_gdinit(&gd->mi, x);
                cpu_gdinit(gd, x);

#if 0
                gd->gd_CMAP1 = pmap_kpte((vm_offset_t)CPU_prvspace[x].CPAGE1);
                gd->gd_CMAP2 = pmap_kpte((vm_offset_t)CPU_prvspace[x].CPAGE2);
                gd->gd_CMAP3 = pmap_kpte((vm_offset_t)CPU_prvspace[x].CPAGE3);
                gd->gd_PMAP1 = pmap_kpte((vm_offset_t)CPU_prvspace[x].PPAGE1);
                gd->gd_CADDR1 = ps->CPAGE1;
                gd->gd_CADDR2 = ps->CPAGE2;
                gd->gd_CADDR3 = ps->CPAGE3;
                gd->gd_PADDR1 = (vpte_t *)ps->PPAGE1;
#endif

                ipiq_size = sizeof(struct lwkt_ipiq) * (naps + 1);
                gd->mi.gd_ipiq = (void *)kmem_alloc(kernel_map, ipiq_size,
                                                    VM_SUBSYS_IPIQ);
                bzero(gd->mi.gd_ipiq, ipiq_size);

                /* initialize arc4random. */
                arc4_init_pcpu(x);

                /*
                 * Setup the AP boot stack
                 */
                bootSTK = &ps->idlestack[UPAGES*PAGE_SIZE/2];
                bootAP = x;

                /*
                 * Setup the AP's lwp, this is the 'cpu'
                 *
                 * We have to make sure our signals are masked or the new LWP
                 * may pick up a signal that it isn't ready for yet.  SMP
                 * startup occurs after SI_BOOT2_LEAVE_CRIT so interrupts
                 * have already been enabled.
                 */
                cpu_disable_intr();

                pthread_create(&ap_tids[x], &attr, start_ap, NULL);
                cpu_enable_intr();

                while (CPUMASK_TESTBIT(smp_startup_mask, x) == 0) {
                        cpu_lfence(); /* XXX spin until the AP has started */
                        DELAY(1000);
                }
        }
        vm_object_drop(kernel_object);
        pthread_attr_destroy(&attr);

        return(ncpus - 1);
}

/*
 * CPU TOPOLOGY DETECTION FUNCTIONS.
 */
void
detect_cpu_topology(void)
{
        logical_CPU_bits = vkernel_b_arg;
        core_bits = vkernel_B_arg;
}

int
get_chip_ID(int cpuid)
{
        return get_apicid_from_cpuid(cpuid) >>
            (logical_CPU_bits + core_bits);
}

int
get_chip_ID_from_APICID(int apicid)
{
        return apicid >> (logical_CPU_bits + core_bits);
}

int
get_core_number_within_chip(int cpuid)
{
        return ((get_apicid_from_cpuid(cpuid) >> logical_CPU_bits) &
                ((1 << core_bits) - 1));
}

int
get_logical_CPU_number_within_core(int cpuid)
{
        return (get_apicid_from_cpuid(cpuid) &
                ((1 << logical_CPU_bits) - 1));
}