MFC 259782:

[FreeBSD/stable/10.git] / sys / amd64 / amd64 / machdep.c

/*-
 * Copyright (c) 2003 Peter Wemm.
 * Copyright (c) 1992 Terrence R. Lambert.
 * Copyright (c) 1982, 1987, 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 *
 *      from: @(#)machdep.c     7.4 (Berkeley) 6/3/91
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "opt_atalk.h"
#include "opt_atpic.h"
#include "opt_compat.h"
#include "opt_cpu.h"
#include "opt_ddb.h"
#include "opt_inet.h"
#include "opt_ipx.h"
#include "opt_isa.h"
#include "opt_kstack_pages.h"
#include "opt_maxmem.h"
#include "opt_mp_watchdog.h"
#include "opt_perfmon.h"
#include "opt_platform.h"
#include "opt_sched.h"
#include "opt_kdtrace.h"

#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/bus.h>
#include <sys/callout.h>
#include <sys/cons.h>
#include <sys/cpu.h>
#include <sys/eventhandler.h>
#include <sys/exec.h>
#include <sys/imgact.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/linker.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/memrange.h>
#include <sys/msgbuf.h>
#include <sys/mutex.h>
#include <sys/pcpu.h>
#include <sys/ptrace.h>
#include <sys/reboot.h>
#include <sys/rwlock.h>
#include <sys/sched.h>
#include <sys/signalvar.h>
#ifdef SMP
#include <sys/smp.h>
#endif
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/ucontext.h>
#include <sys/vmmeter.h>

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

#ifdef DDB
#ifndef KDB
#error KDB must be enabled in order for DDB to work!
#endif
#include <ddb/ddb.h>
#include <ddb/db_sym.h>
#endif

#include <net/netisr.h>

#include <machine/clock.h>
#include <machine/cpu.h>
#include <machine/cputypes.h>
#include <machine/intr_machdep.h>
#include <x86/mca.h>
#include <machine/md_var.h>
#include <machine/metadata.h>
#include <machine/mp_watchdog.h>
#include <machine/pc/bios.h>
#include <machine/pcb.h>
#include <machine/proc.h>
#include <machine/reg.h>
#include <machine/sigframe.h>
#include <machine/specialreg.h>
#ifdef PERFMON
#include <machine/perfmon.h>
#endif
#include <machine/tss.h>
#ifdef SMP
#include <machine/smp.h>
#endif
#ifdef FDT
#include <x86/fdt.h>
#endif

#ifdef DEV_ATPIC
#include <x86/isa/icu.h>
#else
#include <machine/apicvar.h>
#endif

#include <isa/isareg.h>
#include <isa/rtc.h>

/* Sanity check for __curthread() */
CTASSERT(offsetof(struct pcpu, pc_curthread) == 0);

extern u_int64_t hammer_time(u_int64_t, u_int64_t);

extern void printcpuinfo(void); /* XXX header file */
extern void identify_cpu(void);
extern void panicifcpuunsupported(void);

#define CS_SECURE(cs)           (ISPL(cs) == SEL_UPL)
#define EFL_SECURE(ef, oef)     ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)

static void cpu_startup(void *);
static void get_fpcontext(struct thread *td, mcontext_t *mcp,
    char *xfpusave, size_t xfpusave_len);
static int  set_fpcontext(struct thread *td, const mcontext_t *mcp,
    char *xfpustate, size_t xfpustate_len);
SYSINIT(cpu, SI_SUB_CPU, SI_ORDER_FIRST, cpu_startup, NULL);

/*
 * The file "conf/ldscript.amd64" defines the symbol "kernphys".  Its value is
 * the physical address at which the kernel is loaded.
 */
extern char kernphys[];
#ifdef DDB
extern vm_offset_t ksym_start, ksym_end;
#endif

struct msgbuf *msgbufp;

/* Intel ICH registers */
#define ICH_PMBASE      0x400
#define ICH_SMI_EN      ICH_PMBASE + 0x30

int     _udatasel, _ucodesel, _ucode32sel, _ufssel, _ugssel;

int cold = 1;

long Maxmem = 0;
long realmem = 0;

/*
 * The number of PHYSMAP entries must be one less than the number of
 * PHYSSEG entries because the PHYSMAP entry that spans the largest
 * physical address that is accessible by ISA DMA is split into two
 * PHYSSEG entries.
 */
#define PHYSMAP_SIZE    (2 * (VM_PHYSSEG_MAX - 1))

vm_paddr_t phys_avail[PHYSMAP_SIZE + 2];
vm_paddr_t dump_avail[PHYSMAP_SIZE + 2];

/* must be 2 less so 0 0 can signal end of chunks */
#define PHYS_AVAIL_ARRAY_END ((sizeof(phys_avail) / sizeof(phys_avail[0])) - 2)
#define DUMP_AVAIL_ARRAY_END ((sizeof(dump_avail) / sizeof(dump_avail[0])) - 2)

struct kva_md_info kmi;

static struct trapframe proc0_tf;
struct region_descriptor r_gdt, r_idt;

struct pcpu __pcpu[MAXCPU];

struct mtx icu_lock;

struct mem_range_softc mem_range_softc;

struct mtx dt_lock;     /* lock for GDT and LDT */

void (*vmm_resume_p)(void);

static void
cpu_startup(dummy)
        void *dummy;
{
        uintmax_t memsize;
        char *sysenv;

        /*
         * On MacBooks, we need to disallow the legacy USB circuit to
         * generate an SMI# because this can cause several problems,
         * namely: incorrect CPU frequency detection and failure to
         * start the APs.
         * We do this by disabling a bit in the SMI_EN (SMI Control and
         * Enable register) of the Intel ICH LPC Interface Bridge. 
         */
        sysenv = getenv("smbios.system.product");
        if (sysenv != NULL) {
                if (strncmp(sysenv, "MacBook1,1", 10) == 0 ||
                    strncmp(sysenv, "MacBook3,1", 10) == 0 ||
                    strncmp(sysenv, "MacBookPro1,1", 13) == 0 ||
                    strncmp(sysenv, "MacBookPro1,2", 13) == 0 ||
                    strncmp(sysenv, "MacBookPro3,1", 13) == 0 ||
                    strncmp(sysenv, "Macmini1,1", 10) == 0) {
                        if (bootverbose)
                                printf("Disabling LEGACY_USB_EN bit on "
                                    "Intel ICH.\n");
                        outl(ICH_SMI_EN, inl(ICH_SMI_EN) & ~0x8);
                }
                freeenv(sysenv);
        }

        /*
         * Good {morning,afternoon,evening,night}.
         */
        startrtclock();
        printcpuinfo();
        panicifcpuunsupported();
#ifdef PERFMON
        perfmon_init();
#endif

        /*
         * Display physical memory if SMBIOS reports reasonable amount.
         */
        memsize = 0;
        sysenv = getenv("smbios.memory.enabled");
        if (sysenv != NULL) {
                memsize = (uintmax_t)strtoul(sysenv, (char **)NULL, 10) << 10;
                freeenv(sysenv);
        }
        if (memsize < ptoa((uintmax_t)cnt.v_free_count))
                memsize = ptoa((uintmax_t)Maxmem);
        printf("real memory  = %ju (%ju MB)\n", memsize, memsize >> 20);
        realmem = atop(memsize);

        /*
         * Display any holes after the first chunk of extended memory.
         */
        if (bootverbose) {
                int indx;

                printf("Physical memory chunk(s):\n");
                for (indx = 0; phys_avail[indx + 1] != 0; indx += 2) {
                        vm_paddr_t size;

                        size = phys_avail[indx + 1] - phys_avail[indx];
                        printf(
                            "0x%016jx - 0x%016jx, %ju bytes (%ju pages)\n",
                            (uintmax_t)phys_avail[indx],
                            (uintmax_t)phys_avail[indx + 1] - 1,
                            (uintmax_t)size, (uintmax_t)size / PAGE_SIZE);
                }
        }

        vm_ksubmap_init(&kmi);

        printf("avail memory = %ju (%ju MB)\n",
            ptoa((uintmax_t)cnt.v_free_count),
            ptoa((uintmax_t)cnt.v_free_count) / 1048576);

        /*
         * Set up buffers, so they can be used to read disk labels.
         */
        bufinit();
        vm_pager_bufferinit();

        cpu_setregs();
}

/*
 * Send an interrupt to process.
 *
 * Stack is set up to allow sigcode stored
 * at top to call routine, followed by call
 * to sigreturn routine below.  After sigreturn
 * resets the signal mask, the stack, and the
 * frame pointer, it returns to the user
 * specified pc, psl.
 */
void
sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
{
        struct sigframe sf, *sfp;
        struct pcb *pcb;
        struct proc *p;
        struct thread *td;
        struct sigacts *psp;
        char *sp;
        struct trapframe *regs;
        char *xfpusave;
        size_t xfpusave_len;
        int sig;
        int oonstack;

        td = curthread;
        pcb = td->td_pcb;
        p = td->td_proc;
        PROC_LOCK_ASSERT(p, MA_OWNED);
        sig = ksi->ksi_signo;
        psp = p->p_sigacts;
        mtx_assert(&psp->ps_mtx, MA_OWNED);
        regs = td->td_frame;
        oonstack = sigonstack(regs->tf_rsp);

        if (cpu_max_ext_state_size > sizeof(struct savefpu) && use_xsave) {
                xfpusave_len = cpu_max_ext_state_size - sizeof(struct savefpu);
                xfpusave = __builtin_alloca(xfpusave_len);
        } else {
                xfpusave_len = 0;
                xfpusave = NULL;
        }

        /* Save user context. */
        bzero(&sf, sizeof(sf));
        sf.sf_uc.uc_sigmask = *mask;
        sf.sf_uc.uc_stack = td->td_sigstk;
        sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
            ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
        sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
        bcopy(regs, &sf.sf_uc.uc_mcontext.mc_rdi, sizeof(*regs));
        sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */
        get_fpcontext(td, &sf.sf_uc.uc_mcontext, xfpusave, xfpusave_len);
        fpstate_drop(td);
        sf.sf_uc.uc_mcontext.mc_fsbase = pcb->pcb_fsbase;
        sf.sf_uc.uc_mcontext.mc_gsbase = pcb->pcb_gsbase;
        bzero(sf.sf_uc.uc_mcontext.mc_spare,
            sizeof(sf.sf_uc.uc_mcontext.mc_spare));
        bzero(sf.sf_uc.__spare__, sizeof(sf.sf_uc.__spare__));

        /* Allocate space for the signal handler context. */
        if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
            SIGISMEMBER(psp->ps_sigonstack, sig)) {
                sp = td->td_sigstk.ss_sp + td->td_sigstk.ss_size;
#if defined(COMPAT_43)
                td->td_sigstk.ss_flags |= SS_ONSTACK;
#endif
        } else
                sp = (char *)regs->tf_rsp - 128;
        if (xfpusave != NULL) {
                sp -= xfpusave_len;
                sp = (char *)((unsigned long)sp & ~0x3Ful);
                sf.sf_uc.uc_mcontext.mc_xfpustate = (register_t)sp;
        }
        sp -= sizeof(struct sigframe);
        /* Align to 16 bytes. */
        sfp = (struct sigframe *)((unsigned long)sp & ~0xFul);

        /* Translate the signal if appropriate. */
        if (p->p_sysent->sv_sigtbl && sig <= p->p_sysent->sv_sigsize)
                sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)];

        /* Build the argument list for the signal handler. */
        regs->tf_rdi = sig;                     /* arg 1 in %rdi */
        regs->tf_rdx = (register_t)&sfp->sf_uc; /* arg 3 in %rdx */
        bzero(&sf.sf_si, sizeof(sf.sf_si));
        if (SIGISMEMBER(psp->ps_siginfo, sig)) {
                /* Signal handler installed with SA_SIGINFO. */
                regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */
                sf.sf_ahu.sf_action = (__siginfohandler_t *)catcher;

                /* Fill in POSIX parts */
                sf.sf_si = ksi->ksi_info;
                sf.sf_si.si_signo = sig; /* maybe a translated signal */
                regs->tf_rcx = (register_t)ksi->ksi_addr; /* arg 4 in %rcx */
        } else {
                /* Old FreeBSD-style arguments. */
                regs->tf_rsi = ksi->ksi_code;   /* arg 2 in %rsi */
                regs->tf_rcx = (register_t)ksi->ksi_addr; /* arg 4 in %rcx */
                sf.sf_ahu.sf_handler = catcher;
        }
        mtx_unlock(&psp->ps_mtx);
        PROC_UNLOCK(p);

        /*
         * Copy the sigframe out to the user's stack.
         */
        if (copyout(&sf, sfp, sizeof(*sfp)) != 0 ||
            (xfpusave != NULL && copyout(xfpusave,
            (void *)sf.sf_uc.uc_mcontext.mc_xfpustate, xfpusave_len)
            != 0)) {
#ifdef DEBUG
                printf("process %ld has trashed its stack\n", (long)p->p_pid);
#endif
                PROC_LOCK(p);
                sigexit(td, SIGILL);
        }

        regs->tf_rsp = (long)sfp;
        regs->tf_rip = p->p_sysent->sv_sigcode_base;
        regs->tf_rflags &= ~(PSL_T | PSL_D);
        regs->tf_cs = _ucodesel;
        regs->tf_ds = _udatasel;
        regs->tf_es = _udatasel;
        regs->tf_fs = _ufssel;
        regs->tf_gs = _ugssel;
        regs->tf_flags = TF_HASSEGS;
        set_pcb_flags(pcb, PCB_FULL_IRET);
        PROC_LOCK(p);
        mtx_lock(&psp->ps_mtx);
}

/*
 * System call to cleanup state after a signal
 * has been taken.  Reset signal mask and
 * stack state from context left by sendsig (above).
 * Return to previous pc and psl as specified by
 * context left by sendsig. Check carefully to
 * make sure that the user has not modified the
 * state to gain improper privileges.
 *
 * MPSAFE
 */
int
sys_sigreturn(td, uap)
        struct thread *td;
        struct sigreturn_args /* {
                const struct __ucontext *sigcntxp;
        } */ *uap;
{
        ucontext_t uc;
        struct pcb *pcb;
        struct proc *p;
        struct trapframe *regs;
        ucontext_t *ucp;
        char *xfpustate;
        size_t xfpustate_len;
        long rflags;
        int cs, error, ret;
        ksiginfo_t ksi;

        pcb = td->td_pcb;
        p = td->td_proc;

        error = copyin(uap->sigcntxp, &uc, sizeof(uc));
        if (error != 0) {
                uprintf("pid %d (%s): sigreturn copyin failed\n",
                    p->p_pid, td->td_name);
                return (error);
        }
        ucp = &uc;
        if ((ucp->uc_mcontext.mc_flags & ~_MC_FLAG_MASK) != 0) {
                uprintf("pid %d (%s): sigreturn mc_flags %x\n", p->p_pid,
                    td->td_name, ucp->uc_mcontext.mc_flags);
                return (EINVAL);
        }
        regs = td->td_frame;
        rflags = ucp->uc_mcontext.mc_rflags;
        /*
         * Don't allow users to change privileged or reserved flags.
         */
        if (!EFL_SECURE(rflags, regs->tf_rflags)) {
                uprintf("pid %d (%s): sigreturn rflags = 0x%lx\n", p->p_pid,
                    td->td_name, rflags);
                return (EINVAL);
        }

        /*
         * Don't allow users to load a valid privileged %cs.  Let the
         * hardware check for invalid selectors, excess privilege in
         * other selectors, invalid %eip's and invalid %esp's.
         */
        cs = ucp->uc_mcontext.mc_cs;
        if (!CS_SECURE(cs)) {
                uprintf("pid %d (%s): sigreturn cs = 0x%x\n", p->p_pid,
                    td->td_name, cs);
                ksiginfo_init_trap(&ksi);
                ksi.ksi_signo = SIGBUS;
                ksi.ksi_code = BUS_OBJERR;
                ksi.ksi_trapno = T_PROTFLT;
                ksi.ksi_addr = (void *)regs->tf_rip;
                trapsignal(td, &ksi);
                return (EINVAL);
        }

        if ((uc.uc_mcontext.mc_flags & _MC_HASFPXSTATE) != 0) {
                xfpustate_len = uc.uc_mcontext.mc_xfpustate_len;
                if (xfpustate_len > cpu_max_ext_state_size -
                    sizeof(struct savefpu)) {
                        uprintf("pid %d (%s): sigreturn xfpusave_len = 0x%zx\n",
                            p->p_pid, td->td_name, xfpustate_len);
                        return (EINVAL);
                }
                xfpustate = __builtin_alloca(xfpustate_len);
                error = copyin((const void *)uc.uc_mcontext.mc_xfpustate,
                    xfpustate, xfpustate_len);
                if (error != 0) {
                        uprintf(
        "pid %d (%s): sigreturn copying xfpustate failed\n",
                            p->p_pid, td->td_name);
                        return (error);
                }
        } else {
                xfpustate = NULL;
                xfpustate_len = 0;
        }
        ret = set_fpcontext(td, &ucp->uc_mcontext, xfpustate, xfpustate_len);
        if (ret != 0) {
                uprintf("pid %d (%s): sigreturn set_fpcontext err %d\n",
                    p->p_pid, td->td_name, ret);
                return (ret);
        }
        bcopy(&ucp->uc_mcontext.mc_rdi, regs, sizeof(*regs));
        pcb->pcb_fsbase = ucp->uc_mcontext.mc_fsbase;
        pcb->pcb_gsbase = ucp->uc_mcontext.mc_gsbase;

#if defined(COMPAT_43)
        if (ucp->uc_mcontext.mc_onstack & 1)
                td->td_sigstk.ss_flags |= SS_ONSTACK;
        else
                td->td_sigstk.ss_flags &= ~SS_ONSTACK;
#endif

        kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0);
        set_pcb_flags(pcb, PCB_FULL_IRET);
        return (EJUSTRETURN);
}

#ifdef COMPAT_FREEBSD4
int
freebsd4_sigreturn(struct thread *td, struct freebsd4_sigreturn_args *uap)
{
 
        return sys_sigreturn(td, (struct sigreturn_args *)uap);
}
#endif


/*
 * Machine dependent boot() routine
 *
 * I haven't seen anything to put here yet
 * Possibly some stuff might be grafted back here from boot()
 */
void
cpu_boot(int howto)
{
}

/*
 * Flush the D-cache for non-DMA I/O so that the I-cache can
 * be made coherent later.
 */
void
cpu_flush_dcache(void *ptr, size_t len)
{
        /* Not applicable */
}

/* Get current clock frequency for the given cpu id. */
int
cpu_est_clockrate(int cpu_id, uint64_t *rate)
{
        uint64_t tsc1, tsc2;
        uint64_t acnt, mcnt, perf;
        register_t reg;

        if (pcpu_find(cpu_id) == NULL || rate == NULL)
                return (EINVAL);

        /*
         * If TSC is P-state invariant and APERF/MPERF MSRs do not exist,
         * DELAY(9) based logic fails.
         */
        if (tsc_is_invariant && !tsc_perf_stat)
                return (EOPNOTSUPP);

#ifdef SMP
        if (smp_cpus > 1) {
                /* Schedule ourselves on the indicated cpu. */
                thread_lock(curthread);
                sched_bind(curthread, cpu_id);
                thread_unlock(curthread);
        }
#endif

        /* Calibrate by measuring a short delay. */
        reg = intr_disable();
        if (tsc_is_invariant) {
                wrmsr(MSR_MPERF, 0);
                wrmsr(MSR_APERF, 0);
                tsc1 = rdtsc();
                DELAY(1000);
                mcnt = rdmsr(MSR_MPERF);
                acnt = rdmsr(MSR_APERF);
                tsc2 = rdtsc();
                intr_restore(reg);
                perf = 1000 * acnt / mcnt;
                *rate = (tsc2 - tsc1) * perf;
        } else {
                tsc1 = rdtsc();
                DELAY(1000);
                tsc2 = rdtsc();
                intr_restore(reg);
                *rate = (tsc2 - tsc1) * 1000;
        }

#ifdef SMP
        if (smp_cpus > 1) {
                thread_lock(curthread);
                sched_unbind(curthread);
                thread_unlock(curthread);
        }
#endif

        return (0);
}

/*
 * Shutdown the CPU as much as possible
 */
void
cpu_halt(void)
{
        for (;;)
                halt();
}

void (*cpu_idle_hook)(sbintime_t) = NULL;       /* ACPI idle hook. */
static int      cpu_ident_amdc1e = 0;   /* AMD C1E supported. */
static int      idle_mwait = 1;         /* Use MONITOR/MWAIT for short idle. */
TUNABLE_INT("machdep.idle_mwait", &idle_mwait);
SYSCTL_INT(_machdep, OID_AUTO, idle_mwait, CTLFLAG_RW, &idle_mwait,
    0, "Use MONITOR/MWAIT for short idle");

#define STATE_RUNNING   0x0
#define STATE_MWAIT     0x1
#define STATE_SLEEPING  0x2

static void
cpu_idle_acpi(sbintime_t sbt)
{
        int *state;

        state = (int *)PCPU_PTR(monitorbuf);
        *state = STATE_SLEEPING;

        /* See comments in cpu_idle_hlt(). */
        disable_intr();
        if (sched_runnable())
                enable_intr();
        else if (cpu_idle_hook)
                cpu_idle_hook(sbt);
        else
                __asm __volatile("sti; hlt");
        *state = STATE_RUNNING;
}

static void
cpu_idle_hlt(sbintime_t sbt)
{
        int *state;

        state = (int *)PCPU_PTR(monitorbuf);
        *state = STATE_SLEEPING;

        /*
         * Since we may be in a critical section from cpu_idle(), if
         * an interrupt fires during that critical section we may have
         * a pending preemption.  If the CPU halts, then that thread
         * may not execute until a later interrupt awakens the CPU.
         * To handle this race, check for a runnable thread after
         * disabling interrupts and immediately return if one is
         * found.  Also, we must absolutely guarentee that hlt is
         * the next instruction after sti.  This ensures that any
         * interrupt that fires after the call to disable_intr() will
         * immediately awaken the CPU from hlt.  Finally, please note
         * that on x86 this works fine because of interrupts enabled only
         * after the instruction following sti takes place, while IF is set
         * to 1 immediately, allowing hlt instruction to acknowledge the
         * interrupt.
         */
        disable_intr();
        if (sched_runnable())
                enable_intr();
        else
                __asm __volatile("sti; hlt");
        *state = STATE_RUNNING;
}

/*
 * MWAIT cpu power states.  Lower 4 bits are sub-states.
 */
#define MWAIT_C0        0xf0
#define MWAIT_C1        0x00
#define MWAIT_C2        0x10
#define MWAIT_C3        0x20
#define MWAIT_C4        0x30

static void
cpu_idle_mwait(sbintime_t sbt)
{
        int *state;

        state = (int *)PCPU_PTR(monitorbuf);
        *state = STATE_MWAIT;

        /* See comments in cpu_idle_hlt(). */
        disable_intr();
        if (sched_runnable()) {
                enable_intr();
                *state = STATE_RUNNING;
                return;
        }
        cpu_monitor(state, 0, 0);
        if (*state == STATE_MWAIT)
                __asm __volatile("sti; mwait" : : "a" (MWAIT_C1), "c" (0));
        else
                enable_intr();
        *state = STATE_RUNNING;
}

static void
cpu_idle_spin(sbintime_t sbt)
{
        int *state;
        int i;

        state = (int *)PCPU_PTR(monitorbuf);
        *state = STATE_RUNNING;

        /*
         * The sched_runnable() call is racy but as long as there is
         * a loop missing it one time will have just a little impact if any
         * (and it is much better than missing the check at all).
         */
        for (i = 0; i < 1000; i++) {
                if (sched_runnable())
                        return;
                cpu_spinwait();
        }
}

/*
 * C1E renders the local APIC timer dead, so we disable it by
 * reading the Interrupt Pending Message register and clearing
 * both C1eOnCmpHalt (bit 28) and SmiOnCmpHalt (bit 27).
 * 
 * Reference:
 *   "BIOS and Kernel Developer's Guide for AMD NPT Family 0Fh Processors"
 *   #32559 revision 3.00+
 */
#define MSR_AMDK8_IPM           0xc0010055
#define AMDK8_SMIONCMPHALT      (1ULL << 27)
#define AMDK8_C1EONCMPHALT      (1ULL << 28)
#define AMDK8_CMPHALT           (AMDK8_SMIONCMPHALT | AMDK8_C1EONCMPHALT)

static void
cpu_probe_amdc1e(void)
{

        /*
         * Detect the presence of C1E capability mostly on latest
         * dual-cores (or future) k8 family.
         */
        if (cpu_vendor_id == CPU_VENDOR_AMD &&
            (cpu_id & 0x00000f00) == 0x00000f00 &&
            (cpu_id & 0x0fff0000) >=  0x00040000) {
                cpu_ident_amdc1e = 1;
        }
}

void (*cpu_idle_fn)(sbintime_t) = cpu_idle_acpi;

void
cpu_idle(int busy)
{
        uint64_t msr;
        sbintime_t sbt = -1;

        CTR2(KTR_SPARE2, "cpu_idle(%d) at %d",
            busy, curcpu);
#ifdef MP_WATCHDOG
        ap_watchdog(PCPU_GET(cpuid));
#endif
        /* If we are busy - try to use fast methods. */
        if (busy) {
                if ((cpu_feature2 & CPUID2_MON) && idle_mwait) {
                        cpu_idle_mwait(busy);
                        goto out;
                }
        }

        /* If we have time - switch timers into idle mode. */
        if (!busy) {
                critical_enter();
                sbt = cpu_idleclock();
        }

        /* Apply AMD APIC timer C1E workaround. */
        if (cpu_ident_amdc1e && cpu_disable_deep_sleep) {
                msr = rdmsr(MSR_AMDK8_IPM);
                if (msr & AMDK8_CMPHALT)
                        wrmsr(MSR_AMDK8_IPM, msr & ~AMDK8_CMPHALT);
        }

        /* Call main idle method. */
        cpu_idle_fn(sbt);

        /* Switch timers mack into active mode. */
        if (!busy) {
                cpu_activeclock();
                critical_exit();
        }
out:
        CTR2(KTR_SPARE2, "cpu_idle(%d) at %d done",
            busy, curcpu);
}

int
cpu_idle_wakeup(int cpu)
{
        struct pcpu *pcpu;
        int *state;

        pcpu = pcpu_find(cpu);
        state = (int *)pcpu->pc_monitorbuf;
        /*
         * This doesn't need to be atomic since missing the race will
         * simply result in unnecessary IPIs.
         */
        if (*state == STATE_SLEEPING)
                return (0);
        if (*state == STATE_MWAIT)
                *state = STATE_RUNNING;
        return (1);
}

/*
 * Ordered by speed/power consumption.
 */
struct {
        void    *id_fn;
        char    *id_name;
} idle_tbl[] = {
        { cpu_idle_spin, "spin" },
        { cpu_idle_mwait, "mwait" },
        { cpu_idle_hlt, "hlt" },
        { cpu_idle_acpi, "acpi" },
        { NULL, NULL }
};

static int
idle_sysctl_available(SYSCTL_HANDLER_ARGS)
{
        char *avail, *p;
        int error;
        int i;

        avail = malloc(256, M_TEMP, M_WAITOK);
        p = avail;
        for (i = 0; idle_tbl[i].id_name != NULL; i++) {
                if (strstr(idle_tbl[i].id_name, "mwait") &&
                    (cpu_feature2 & CPUID2_MON) == 0)
                        continue;
                if (strcmp(idle_tbl[i].id_name, "acpi") == 0 &&
                    cpu_idle_hook == NULL)
                        continue;
                p += sprintf(p, "%s%s", p != avail ? ", " : "",
                    idle_tbl[i].id_name);
        }
        error = sysctl_handle_string(oidp, avail, 0, req);
        free(avail, M_TEMP);
        return (error);
}

SYSCTL_PROC(_machdep, OID_AUTO, idle_available, CTLTYPE_STRING | CTLFLAG_RD,
    0, 0, idle_sysctl_available, "A", "list of available idle functions");

static int
idle_sysctl(SYSCTL_HANDLER_ARGS)
{
        char buf[16];
        int error;
        char *p;
        int i;

        p = "unknown";
        for (i = 0; idle_tbl[i].id_name != NULL; i++) {
                if (idle_tbl[i].id_fn == cpu_idle_fn) {
                        p = idle_tbl[i].id_name;
                        break;
                }
        }
        strncpy(buf, p, sizeof(buf));
        error = sysctl_handle_string(oidp, buf, sizeof(buf), req);
        if (error != 0 || req->newptr == NULL)
                return (error);
        for (i = 0; idle_tbl[i].id_name != NULL; i++) {
                if (strstr(idle_tbl[i].id_name, "mwait") &&
                    (cpu_feature2 & CPUID2_MON) == 0)
                        continue;
                if (strcmp(idle_tbl[i].id_name, "acpi") == 0 &&
                    cpu_idle_hook == NULL)
                        continue;
                if (strcmp(idle_tbl[i].id_name, buf))
                        continue;
                cpu_idle_fn = idle_tbl[i].id_fn;
                return (0);
        }
        return (EINVAL);
}

SYSCTL_PROC(_machdep, OID_AUTO, idle, CTLTYPE_STRING | CTLFLAG_RW, 0, 0,
    idle_sysctl, "A", "currently selected idle function");

/*
 * Reset registers to default values on exec.
 */
void
exec_setregs(struct thread *td, struct image_params *imgp, u_long stack)
{
        struct trapframe *regs = td->td_frame;
        struct pcb *pcb = td->td_pcb;

        mtx_lock(&dt_lock);
        if (td->td_proc->p_md.md_ldt != NULL)
                user_ldt_free(td);
        else
                mtx_unlock(&dt_lock);
        
        pcb->pcb_fsbase = 0;
        pcb->pcb_gsbase = 0;
        clear_pcb_flags(pcb, PCB_32BIT);
        pcb->pcb_initial_fpucw = __INITIAL_FPUCW__;
        set_pcb_flags(pcb, PCB_FULL_IRET);

        bzero((char *)regs, sizeof(struct trapframe));
        regs->tf_rip = imgp->entry_addr;
        regs->tf_rsp = ((stack - 8) & ~0xFul) + 8;
        regs->tf_rdi = stack;           /* argv */
        regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T);
        regs->tf_ss = _udatasel;
        regs->tf_cs = _ucodesel;
        regs->tf_ds = _udatasel;
        regs->tf_es = _udatasel;
        regs->tf_fs = _ufssel;
        regs->tf_gs = _ugssel;
        regs->tf_flags = TF_HASSEGS;
        td->td_retval[1] = 0;

        /*
         * Reset the hardware debug registers if they were in use.
         * They won't have any meaning for the newly exec'd process.
         */
        if (pcb->pcb_flags & PCB_DBREGS) {
                pcb->pcb_dr0 = 0;
                pcb->pcb_dr1 = 0;
                pcb->pcb_dr2 = 0;
                pcb->pcb_dr3 = 0;
                pcb->pcb_dr6 = 0;
                pcb->pcb_dr7 = 0;
                if (pcb == curpcb) {
                        /*
                         * Clear the debug registers on the running
                         * CPU, otherwise they will end up affecting
                         * the next process we switch to.
                         */
                        reset_dbregs();
                }
                clear_pcb_flags(pcb, PCB_DBREGS);
        }

        /*
         * Drop the FP state if we hold it, so that the process gets a
         * clean FP state if it uses the FPU again.
         */
        fpstate_drop(td);
}

void
cpu_setregs(void)
{
        register_t cr0;

        cr0 = rcr0();
        /*
         * CR0_MP, CR0_NE and CR0_TS are also set by npx_probe() for the
         * BSP.  See the comments there about why we set them.
         */
        cr0 |= CR0_MP | CR0_NE | CR0_TS | CR0_WP | CR0_AM;
        load_cr0(cr0);
}

/*
 * Initialize amd64 and configure to run kernel
 */

/*
 * Initialize segments & interrupt table
 */

struct user_segment_descriptor gdt[NGDT * MAXCPU];/* global descriptor tables */
static struct gate_descriptor idt0[NIDT];
struct gate_descriptor *idt = &idt0[0]; /* interrupt descriptor table */

static char dblfault_stack[PAGE_SIZE] __aligned(16);

static char nmi0_stack[PAGE_SIZE] __aligned(16);
CTASSERT(sizeof(struct nmi_pcpu) == 16);

struct amd64tss common_tss[MAXCPU];

/*
 * Software prototypes -- in more palatable form.
 *
 * Keep GUFS32, GUGS32, GUCODE32 and GUDATA at the same
 * slots as corresponding segments for i386 kernel.
 */
struct soft_segment_descriptor gdt_segs[] = {
/* GNULL_SEL    0 Null Descriptor */
{       .ssd_base = 0x0,
        .ssd_limit = 0x0,
        .ssd_type = 0,
        .ssd_dpl = 0,
        .ssd_p = 0,
        .ssd_long = 0,
        .ssd_def32 = 0,
        .ssd_gran = 0           },
/* GNULL2_SEL   1 Null Descriptor */
{       .ssd_base = 0x0,
        .ssd_limit = 0x0,
        .ssd_type = 0,
        .ssd_dpl = 0,
        .ssd_p = 0,
        .ssd_long = 0,
        .ssd_def32 = 0,
        .ssd_gran = 0           },
/* GUFS32_SEL   2 32 bit %gs Descriptor for user */
{       .ssd_base = 0x0,
        .ssd_limit = 0xfffff,
        .ssd_type = SDT_MEMRWA,
        .ssd_dpl = SEL_UPL,
        .ssd_p = 1,
        .ssd_long = 0,
        .ssd_def32 = 1,
        .ssd_gran = 1           },
/* GUGS32_SEL   3 32 bit %fs Descriptor for user */
{       .ssd_base = 0x0,
        .ssd_limit = 0xfffff,
        .ssd_type = SDT_MEMRWA,
        .ssd_dpl = SEL_UPL,
        .ssd_p = 1,
        .ssd_long = 0,
        .ssd_def32 = 1,
        .ssd_gran = 1           },
/* GCODE_SEL    4 Code Descriptor for kernel */
{       .ssd_base = 0x0,
        .ssd_limit = 0xfffff,
        .ssd_type = SDT_MEMERA,
        .ssd_dpl = SEL_KPL,
        .ssd_p = 1,
        .ssd_long = 1,
        .ssd_def32 = 0,
        .ssd_gran = 1           },
/* GDATA_SEL    5 Data Descriptor for kernel */
{       .ssd_base = 0x0,
        .ssd_limit = 0xfffff,
        .ssd_type = SDT_MEMRWA,
        .ssd_dpl = SEL_KPL,
        .ssd_p = 1,
        .ssd_long = 1,
        .ssd_def32 = 0,
        .ssd_gran = 1           },
/* GUCODE32_SEL 6 32 bit Code Descriptor for user */
{       .ssd_base = 0x0,
        .ssd_limit = 0xfffff,
        .ssd_type = SDT_MEMERA,
        .ssd_dpl = SEL_UPL,
        .ssd_p = 1,
        .ssd_long = 0,
        .ssd_def32 = 1,
        .ssd_gran = 1           },
/* GUDATA_SEL   7 32/64 bit Data Descriptor for user */
{       .ssd_base = 0x0,
        .ssd_limit = 0xfffff,
        .ssd_type = SDT_MEMRWA,
        .ssd_dpl = SEL_UPL,
        .ssd_p = 1,
        .ssd_long = 0,
        .ssd_def32 = 1,
        .ssd_gran = 1           },
/* GUCODE_SEL   8 64 bit Code Descriptor for user */
{       .ssd_base = 0x0,
        .ssd_limit = 0xfffff,
        .ssd_type = SDT_MEMERA,
        .ssd_dpl = SEL_UPL,
        .ssd_p = 1,
        .ssd_long = 1,
        .ssd_def32 = 0,
        .ssd_gran = 1           },
/* GPROC0_SEL   9 Proc 0 Tss Descriptor */
{       .ssd_base = 0x0,
        .ssd_limit = sizeof(struct amd64tss) + IOPAGES * PAGE_SIZE - 1,
        .ssd_type = SDT_SYSTSS,
        .ssd_dpl = SEL_KPL,
        .ssd_p = 1,
        .ssd_long = 0,
        .ssd_def32 = 0,
        .ssd_gran = 0           },
/* Actually, the TSS is a system descriptor which is double size */
{       .ssd_base = 0x0,
        .ssd_limit = 0x0,
        .ssd_type = 0,
        .ssd_dpl = 0,
        .ssd_p = 0,
        .ssd_long = 0,
        .ssd_def32 = 0,
        .ssd_gran = 0           },
/* GUSERLDT_SEL 11 LDT Descriptor */
{       .ssd_base = 0x0,
        .ssd_limit = 0x0,
        .ssd_type = 0,
        .ssd_dpl = 0,
        .ssd_p = 0,
        .ssd_long = 0,
        .ssd_def32 = 0,
        .ssd_gran = 0           },
/* GUSERLDT_SEL 12 LDT Descriptor, double size */
{       .ssd_base = 0x0,
        .ssd_limit = 0x0,
        .ssd_type = 0,
        .ssd_dpl = 0,
        .ssd_p = 0,
        .ssd_long = 0,
        .ssd_def32 = 0,
        .ssd_gran = 0           },
};

void
setidt(idx, func, typ, dpl, ist)
        int idx;
        inthand_t *func;
        int typ;
        int dpl;
        int ist;
{
        struct gate_descriptor *ip;

        ip = idt + idx;
        ip->gd_looffset = (uintptr_t)func;
        ip->gd_selector = GSEL(GCODE_SEL, SEL_KPL);
        ip->gd_ist = ist;
        ip->gd_xx = 0;
        ip->gd_type = typ;
        ip->gd_dpl = dpl;
        ip->gd_p = 1;
        ip->gd_hioffset = ((uintptr_t)func)>>16 ;
}

extern inthand_t
        IDTVEC(div), IDTVEC(dbg), IDTVEC(nmi), IDTVEC(bpt), IDTVEC(ofl),
        IDTVEC(bnd), IDTVEC(ill), IDTVEC(dna), IDTVEC(fpusegm),
        IDTVEC(tss), IDTVEC(missing), IDTVEC(stk), IDTVEC(prot),
        IDTVEC(page), IDTVEC(mchk), IDTVEC(rsvd), IDTVEC(fpu), IDTVEC(align),
        IDTVEC(xmm), IDTVEC(dblfault),
#ifdef KDTRACE_HOOKS
        IDTVEC(dtrace_ret),
#endif
#ifdef XENHVM
        IDTVEC(xen_intr_upcall),
#endif
        IDTVEC(fast_syscall), IDTVEC(fast_syscall32);

#ifdef DDB
/*
 * Display the index and function name of any IDT entries that don't use
 * the default 'rsvd' entry point.
 */
DB_SHOW_COMMAND(idt, db_show_idt)
{
        struct gate_descriptor *ip;
        int idx;
        uintptr_t func;

        ip = idt;
        for (idx = 0; idx < NIDT && !db_pager_quit; idx++) {
                func = ((long)ip->gd_hioffset << 16 | ip->gd_looffset);
                if (func != (uintptr_t)&IDTVEC(rsvd)) {
                        db_printf("%3d\t", idx);
                        db_printsym(func, DB_STGY_PROC);
                        db_printf("\n");
                }
                ip++;
        }
}

/* Show privileged registers. */
DB_SHOW_COMMAND(sysregs, db_show_sysregs)
{
        struct {
                uint16_t limit;
                uint64_t base;
        } __packed idtr, gdtr;
        uint16_t ldt, tr;

        __asm __volatile("sidt %0" : "=m" (idtr));
        db_printf("idtr\t0x%016lx/%04x\n",
            (u_long)idtr.base, (u_int)idtr.limit);
        __asm __volatile("sgdt %0" : "=m" (gdtr));
        db_printf("gdtr\t0x%016lx/%04x\n",
            (u_long)gdtr.base, (u_int)gdtr.limit);
        __asm __volatile("sldt %0" : "=r" (ldt));
        db_printf("ldtr\t0x%04x\n", ldt);
        __asm __volatile("str %0" : "=r" (tr));
        db_printf("tr\t0x%04x\n", tr);
        db_printf("cr0\t0x%016lx\n", rcr0());
        db_printf("cr2\t0x%016lx\n", rcr2());
        db_printf("cr3\t0x%016lx\n", rcr3());
        db_printf("cr4\t0x%016lx\n", rcr4());
        db_printf("EFER\t%016lx\n", rdmsr(MSR_EFER));
        db_printf("FEATURES_CTL\t%016lx\n", rdmsr(MSR_IA32_FEATURE_CONTROL));
        db_printf("DEBUG_CTL\t%016lx\n", rdmsr(MSR_DEBUGCTLMSR));
        db_printf("PAT\t%016lx\n", rdmsr(MSR_PAT));
        db_printf("GSBASE\t%016lx\n", rdmsr(MSR_GSBASE));
}
#endif

void
sdtossd(sd, ssd)
        struct user_segment_descriptor *sd;
        struct soft_segment_descriptor *ssd;
{

        ssd->ssd_base  = (sd->sd_hibase << 24) | sd->sd_lobase;
        ssd->ssd_limit = (sd->sd_hilimit << 16) | sd->sd_lolimit;
        ssd->ssd_type  = sd->sd_type;
        ssd->ssd_dpl   = sd->sd_dpl;
        ssd->ssd_p     = sd->sd_p;
        ssd->ssd_long  = sd->sd_long;
        ssd->ssd_def32 = sd->sd_def32;
        ssd->ssd_gran  = sd->sd_gran;
}

void
ssdtosd(ssd, sd)
        struct soft_segment_descriptor *ssd;
        struct user_segment_descriptor *sd;
{

        sd->sd_lobase = (ssd->ssd_base) & 0xffffff;
        sd->sd_hibase = (ssd->ssd_base >> 24) & 0xff;
        sd->sd_lolimit = (ssd->ssd_limit) & 0xffff;
        sd->sd_hilimit = (ssd->ssd_limit >> 16) & 0xf;
        sd->sd_type  = ssd->ssd_type;
        sd->sd_dpl   = ssd->ssd_dpl;
        sd->sd_p     = ssd->ssd_p;
        sd->sd_long  = ssd->ssd_long;
        sd->sd_def32 = ssd->ssd_def32;
        sd->sd_gran  = ssd->ssd_gran;
}

void
ssdtosyssd(ssd, sd)
        struct soft_segment_descriptor *ssd;
        struct system_segment_descriptor *sd;
{

        sd->sd_lobase = (ssd->ssd_base) & 0xffffff;
        sd->sd_hibase = (ssd->ssd_base >> 24) & 0xfffffffffful;
        sd->sd_lolimit = (ssd->ssd_limit) & 0xffff;
        sd->sd_hilimit = (ssd->ssd_limit >> 16) & 0xf;
        sd->sd_type  = ssd->ssd_type;
        sd->sd_dpl   = ssd->ssd_dpl;
        sd->sd_p     = ssd->ssd_p;
        sd->sd_gran  = ssd->ssd_gran;
}

#if !defined(DEV_ATPIC) && defined(DEV_ISA)
#include <isa/isavar.h>
#include <isa/isareg.h>
/*
 * Return a bitmap of the current interrupt requests.  This is 8259-specific
 * and is only suitable for use at probe time.
 * This is only here to pacify sio.  It is NOT FATAL if this doesn't work.
 * It shouldn't be here.  There should probably be an APIC centric
 * implementation in the apic driver code, if at all.
 */
intrmask_t
isa_irq_pending(void)
{
        u_char irr1;
        u_char irr2;

        irr1 = inb(IO_ICU1);
        irr2 = inb(IO_ICU2);
        return ((irr2 << 8) | irr1);
}
#endif

u_int basemem;

static int
add_smap_entry(struct bios_smap *smap, vm_paddr_t *physmap, int *physmap_idxp)
{
        int i, insert_idx, physmap_idx;

        physmap_idx = *physmap_idxp;

        if (boothowto & RB_VERBOSE)
                printf("SMAP type=%02x base=%016lx len=%016lx\n",
                    smap->type, smap->base, smap->length);

        if (smap->type != SMAP_TYPE_MEMORY)
                return (1);

        if (smap->length == 0)
                return (0);

        /*
         * Find insertion point while checking for overlap.  Start off by
         * assuming the new entry will be added to the end.
         */
        insert_idx = physmap_idx + 2;
        for (i = 0; i <= physmap_idx; i += 2) {
                if (smap->base < physmap[i + 1]) {
                        if (smap->base + smap->length <= physmap[i]) {
                                insert_idx = i;
                                break;
                        }
                        if (boothowto & RB_VERBOSE)
                                printf(
                    "Overlapping memory regions, ignoring second region\n");
                        return (1);
                }
        }

        /* See if we can prepend to the next entry. */
        if (insert_idx <= physmap_idx &&
            smap->base + smap->length == physmap[insert_idx]) {
                physmap[insert_idx] = smap->base;
                return (1);
        }

        /* See if we can append to the previous entry. */
        if (insert_idx > 0 && smap->base == physmap[insert_idx - 1]) {
                physmap[insert_idx - 1] += smap->length;
                return (1);
        }

        physmap_idx += 2;
        *physmap_idxp = physmap_idx;
        if (physmap_idx == PHYSMAP_SIZE) {
                printf(
                "Too many segments in the physical address map, giving up\n");
                return (0);
        }

        /*
         * Move the last 'N' entries down to make room for the new
         * entry if needed.
         */
        for (i = physmap_idx; i > insert_idx; i -= 2) {
                physmap[i] = physmap[i - 2];
                physmap[i + 1] = physmap[i - 1];
        }

        /* Insert the new entry. */
        physmap[insert_idx] = smap->base;
        physmap[insert_idx + 1] = smap->base + smap->length;
        return (1);
}

/*
 * Populate the (physmap) array with base/bound pairs describing the
 * available physical memory in the system, then test this memory and
 * build the phys_avail array describing the actually-available memory.
 *
 * Total memory size may be set by the kernel environment variable
 * hw.physmem or the compile-time define MAXMEM.
 *
 * XXX first should be vm_paddr_t.
 */
static void
getmemsize(caddr_t kmdp, u_int64_t first)
{
        int i, physmap_idx, pa_indx, da_indx;
        vm_paddr_t pa, physmap[PHYSMAP_SIZE];
        u_long physmem_start, physmem_tunable, memtest;
        pt_entry_t *pte;
        struct bios_smap *smapbase, *smap, *smapend;
        u_int32_t smapsize;
        quad_t dcons_addr, dcons_size;

        bzero(physmap, sizeof(physmap));
        basemem = 0;
        physmap_idx = 0;

        /*
         * get memory map from INT 15:E820, kindly supplied by the loader.
         *
         * subr_module.c says:
         * "Consumer may safely assume that size value precedes data."
         * ie: an int32_t immediately precedes smap.
         */
        smapbase = (struct bios_smap *)preload_search_info(kmdp,
            MODINFO_METADATA | MODINFOMD_SMAP);
        if (smapbase == NULL)
                panic("No BIOS smap info from loader!");

        smapsize = *((u_int32_t *)smapbase - 1);
        smapend = (struct bios_smap *)((uintptr_t)smapbase + smapsize);

        for (smap = smapbase; smap < smapend; smap++)
                if (!add_smap_entry(smap, physmap, &physmap_idx))
                        break;

        /*
         * Find the 'base memory' segment for SMP
         */
        basemem = 0;
        for (i = 0; i <= physmap_idx; i += 2) {
                if (physmap[i] == 0x00000000) {
                        basemem = physmap[i + 1] / 1024;
                        break;
                }
        }
        if (basemem == 0)
                panic("BIOS smap did not include a basemem segment!");

#ifdef SMP
        /* make hole for AP bootstrap code */
        physmap[1] = mp_bootaddress(physmap[1] / 1024);
#endif

        /*
         * Maxmem isn't the "maximum memory", it's one larger than the
         * highest page of the physical address space.  It should be
         * called something like "Maxphyspage".  We may adjust this
         * based on ``hw.physmem'' and the results of the memory test.
         */
        Maxmem = atop(physmap[physmap_idx + 1]);

#ifdef MAXMEM
        Maxmem = MAXMEM / 4;
#endif

        if (TUNABLE_ULONG_FETCH("hw.physmem", &physmem_tunable))
                Maxmem = atop(physmem_tunable);

        /*
         * By default enable the memory test on real hardware, and disable
         * it if we appear to be running in a VM.  This avoids touching all
         * pages unnecessarily, which doesn't matter on real hardware but is
         * bad for shared VM hosts.  Use a general name so that
         * one could eventually do more with the code than just disable it.
         */
        memtest = (vm_guest > VM_GUEST_NO) ? 0 : 1;
        TUNABLE_ULONG_FETCH("hw.memtest.tests", &memtest);

        /*
         * Don't allow MAXMEM or hw.physmem to extend the amount of memory
         * in the system.
         */
        if (Maxmem > atop(physmap[physmap_idx + 1]))
                Maxmem = atop(physmap[physmap_idx + 1]);

        if (atop(physmap[physmap_idx + 1]) != Maxmem &&
            (boothowto & RB_VERBOSE))
                printf("Physical memory use set to %ldK\n", Maxmem * 4);

        /* call pmap initialization to make new kernel address space */
        pmap_bootstrap(&first);

        /*
         * Size up each available chunk of physical memory.
         *
         * XXX Some BIOSes corrupt low 64KB between suspend and resume.
         * By default, mask off the first 16 pages unless we appear to be
         * running in a VM.
         */
        physmem_start = (vm_guest > VM_GUEST_NO ? 1 : 16) << PAGE_SHIFT;
        TUNABLE_ULONG_FETCH("hw.physmem.start", &physmem_start);
        if (physmem_start < PAGE_SIZE)
                physmap[0] = PAGE_SIZE;
        else if (physmem_start >= physmap[1])
                physmap[0] = round_page(physmap[1] - PAGE_SIZE);
        else
                physmap[0] = round_page(physmem_start);
        pa_indx = 0;
        da_indx = 1;
        phys_avail[pa_indx++] = physmap[0];
        phys_avail[pa_indx] = physmap[0];
        dump_avail[da_indx] = physmap[0];
        pte = CMAP1;

        /*
         * Get dcons buffer address
         */
        if (getenv_quad("dcons.addr", &dcons_addr) == 0 ||
            getenv_quad("dcons.size", &dcons_size) == 0)
                dcons_addr = 0;

        /*
         * physmap is in bytes, so when converting to page boundaries,
         * round up the start address and round down the end address.
         */
        for (i = 0; i <= physmap_idx; i += 2) {
                vm_paddr_t end;

                end = ptoa((vm_paddr_t)Maxmem);
                if (physmap[i + 1] < end)
                        end = trunc_page(physmap[i + 1]);
                for (pa = round_page(physmap[i]); pa < end; pa += PAGE_SIZE) {
                        int tmp, page_bad, full;
                        int *ptr = (int *)CADDR1;

                        full = FALSE;
                        /*
                         * block out kernel memory as not available.
                         */
                        if (pa >= (vm_paddr_t)kernphys && pa < first)
                                goto do_dump_avail;

                        /*
                         * block out dcons buffer
                         */
                        if (dcons_addr > 0
                            && pa >= trunc_page(dcons_addr)
                            && pa < dcons_addr + dcons_size)
                                goto do_dump_avail;

                        page_bad = FALSE;
                        if (memtest == 0)
                                goto skip_memtest;

                        /*
                         * map page into kernel: valid, read/write,non-cacheable
                         */
                        *pte = pa | PG_V | PG_RW | PG_NC_PWT | PG_NC_PCD;
                        invltlb();

                        tmp = *(int *)ptr;
                        /*
                         * Test for alternating 1's and 0's
                         */
                        *(volatile int *)ptr = 0xaaaaaaaa;
                        if (*(volatile int *)ptr != 0xaaaaaaaa)
                                page_bad = TRUE;
                        /*
                         * Test for alternating 0's and 1's
                         */
                        *(volatile int *)ptr = 0x55555555;
                        if (*(volatile int *)ptr != 0x55555555)
                                page_bad = TRUE;
                        /*
                         * Test for all 1's
                         */
                        *(volatile int *)ptr = 0xffffffff;
                        if (*(volatile int *)ptr != 0xffffffff)
                                page_bad = TRUE;
                        /*
                         * Test for all 0's
                         */
                        *(volatile int *)ptr = 0x0;
                        if (*(volatile int *)ptr != 0x0)
                                page_bad = TRUE;
                        /*
                         * Restore original value.
                         */
                        *(int *)ptr = tmp;

skip_memtest:
                        /*
                         * Adjust array of valid/good pages.
                         */
                        if (page_bad == TRUE)
                                continue;
                        /*
                         * If this good page is a continuation of the
                         * previous set of good pages, then just increase
                         * the end pointer. Otherwise start a new chunk.
                         * Note that "end" points one higher than end,
                         * making the range >= start and < end.
                         * If we're also doing a speculative memory
                         * test and we at or past the end, bump up Maxmem
                         * so that we keep going. The first bad page
                         * will terminate the loop.
                         */
                        if (phys_avail[pa_indx] == pa) {
                                phys_avail[pa_indx] += PAGE_SIZE;
                        } else {
                                pa_indx++;
                                if (pa_indx == PHYS_AVAIL_ARRAY_END) {
                                        printf(
                "Too many holes in the physical address space, giving up\n");
                                        pa_indx--;
                                        full = TRUE;
                                        goto do_dump_avail;
                                }
                                phys_avail[pa_indx++] = pa;     /* start */
                                phys_avail[pa_indx] = pa + PAGE_SIZE; /* end */
                        }
                        physmem++;
do_dump_avail:
                        if (dump_avail[da_indx] == pa) {
                                dump_avail[da_indx] += PAGE_SIZE;
                        } else {
                                da_indx++;
                                if (da_indx == DUMP_AVAIL_ARRAY_END) {
                                        da_indx--;
                                        goto do_next;
                                }
                                dump_avail[da_indx++] = pa; /* start */
                                dump_avail[da_indx] = pa + PAGE_SIZE; /* end */
                        }
do_next:
                        if (full)
                                break;
                }
        }
        *pte = 0;
        invltlb();

        /*
         * XXX
         * The last chunk must contain at least one page plus the message
         * buffer to avoid complicating other code (message buffer address
         * calculation, etc.).
         */
        while (phys_avail[pa_indx - 1] + PAGE_SIZE +
            round_page(msgbufsize) >= phys_avail[pa_indx]) {
                physmem -= atop(phys_avail[pa_indx] - phys_avail[pa_indx - 1]);
                phys_avail[pa_indx--] = 0;
                phys_avail[pa_indx--] = 0;
        }

        Maxmem = atop(phys_avail[pa_indx]);

        /* Trim off space for the message buffer. */
        phys_avail[pa_indx] -= round_page(msgbufsize);

        /* Map the message buffer. */
        msgbufp = (struct msgbuf *)PHYS_TO_DMAP(phys_avail[pa_indx]);
}

u_int64_t
hammer_time(u_int64_t modulep, u_int64_t physfree)
{
        caddr_t kmdp;
        int gsel_tss, x;
        struct pcpu *pc;
        struct nmi_pcpu *np;
        struct xstate_hdr *xhdr;
        u_int64_t msr;
        char *env;
        size_t kstack0_sz;

        thread0.td_kstack = physfree + KERNBASE;
        thread0.td_kstack_pages = KSTACK_PAGES;
        kstack0_sz = thread0.td_kstack_pages * PAGE_SIZE;
        bzero((void *)thread0.td_kstack, kstack0_sz);
        physfree += kstack0_sz;

        /*
         * This may be done better later if it gets more high level
         * components in it. If so just link td->td_proc here.
         */
        proc_linkup0(&proc0, &thread0);

        preload_metadata = (caddr_t)(uintptr_t)(modulep + KERNBASE);
        preload_bootstrap_relocate(KERNBASE);
        kmdp = preload_search_by_type("elf kernel");
        if (kmdp == NULL)
                kmdp = preload_search_by_type("elf64 kernel");
        boothowto = MD_FETCH(kmdp, MODINFOMD_HOWTO, int);
        kern_envp = MD_FETCH(kmdp, MODINFOMD_ENVP, char *) + KERNBASE;
#ifdef DDB
        ksym_start = MD_FETCH(kmdp, MODINFOMD_SSYM, uintptr_t);
        ksym_end = MD_FETCH(kmdp, MODINFOMD_ESYM, uintptr_t);
#endif

        /* Init basic tunables, hz etc */
        init_param1();

        /*
         * make gdt memory segments
         */
        for (x = 0; x < NGDT; x++) {
                if (x != GPROC0_SEL && x != (GPROC0_SEL + 1) &&
                    x != GUSERLDT_SEL && x != (GUSERLDT_SEL) + 1)
                        ssdtosd(&gdt_segs[x], &gdt[x]);
        }
        gdt_segs[GPROC0_SEL].ssd_base = (uintptr_t)&common_tss[0];
        ssdtosyssd(&gdt_segs[GPROC0_SEL],
            (struct system_segment_descriptor *)&gdt[GPROC0_SEL]);

        r_gdt.rd_limit = NGDT * sizeof(gdt[0]) - 1;
        r_gdt.rd_base =  (long) gdt;
        lgdt(&r_gdt);
        pc = &__pcpu[0];

        wrmsr(MSR_FSBASE, 0);           /* User value */
        wrmsr(MSR_GSBASE, (u_int64_t)pc);
        wrmsr(MSR_KGSBASE, 0);          /* User value while in the kernel */

        pcpu_init(pc, 0, sizeof(struct pcpu));
        dpcpu_init((void *)(physfree + KERNBASE), 0);
        physfree += DPCPU_SIZE;
        PCPU_SET(prvspace, pc);
        PCPU_SET(curthread, &thread0);
        PCPU_SET(tssp, &common_tss[0]);
        PCPU_SET(commontssp, &common_tss[0]);
        PCPU_SET(tss, (struct system_segment_descriptor *)&gdt[GPROC0_SEL]);
        PCPU_SET(ldt, (struct system_segment_descriptor *)&gdt[GUSERLDT_SEL]);
        PCPU_SET(fs32p, &gdt[GUFS32_SEL]);
        PCPU_SET(gs32p, &gdt[GUGS32_SEL]);

        /*
         * Initialize mutexes.
         *
         * icu_lock: in order to allow an interrupt to occur in a critical
         *           section, to set pcpu->ipending (etc...) properly, we
         *           must be able to get the icu lock, so it can't be
         *           under witness.
         */
        mutex_init();
        mtx_init(&icu_lock, "icu", NULL, MTX_SPIN | MTX_NOWITNESS);
        mtx_init(&dt_lock, "descriptor tables", NULL, MTX_DEF);

        /* exceptions */
        for (x = 0; x < NIDT; x++)
                setidt(x, &IDTVEC(rsvd), SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_DE, &IDTVEC(div),  SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_DB, &IDTVEC(dbg),  SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_NMI, &IDTVEC(nmi),  SDT_SYSIGT, SEL_KPL, 2);
        setidt(IDT_BP, &IDTVEC(bpt),  SDT_SYSIGT, SEL_UPL, 0);
        setidt(IDT_OF, &IDTVEC(ofl),  SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_BR, &IDTVEC(bnd),  SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_UD, &IDTVEC(ill),  SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_NM, &IDTVEC(dna),  SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_DF, &IDTVEC(dblfault), SDT_SYSIGT, SEL_KPL, 1);
        setidt(IDT_FPUGP, &IDTVEC(fpusegm),  SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_TS, &IDTVEC(tss),  SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_NP, &IDTVEC(missing),  SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_SS, &IDTVEC(stk),  SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_GP, &IDTVEC(prot),  SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_PF, &IDTVEC(page),  SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_MF, &IDTVEC(fpu),  SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_AC, &IDTVEC(align), SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_MC, &IDTVEC(mchk),  SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_XF, &IDTVEC(xmm), SDT_SYSIGT, SEL_KPL, 0);
#ifdef KDTRACE_HOOKS
        setidt(IDT_DTRACE_RET, &IDTVEC(dtrace_ret), SDT_SYSIGT, SEL_UPL, 0);
#endif
#ifdef XENHVM
        setidt(IDT_EVTCHN, &IDTVEC(xen_intr_upcall), SDT_SYSIGT, SEL_UPL, 0);
#endif

        r_idt.rd_limit = sizeof(idt0) - 1;
        r_idt.rd_base = (long) idt;
        lidt(&r_idt);

        /*
         * Initialize the i8254 before the console so that console
         * initialization can use DELAY().
         */
        i8254_init();

        /*
         * Initialize the console before we print anything out.
         */
        cninit();

#ifdef DEV_ISA
#ifdef DEV_ATPIC
        elcr_probe();
        atpic_startup();
#else
        /* Reset and mask the atpics and leave them shut down. */
        atpic_reset();

        /*
         * Point the ICU spurious interrupt vectors at the APIC spurious
         * interrupt handler.
         */
        setidt(IDT_IO_INTS + 7, IDTVEC(spuriousint), SDT_SYSIGT, SEL_KPL, 0);
        setidt(IDT_IO_INTS + 15, IDTVEC(spuriousint), SDT_SYSIGT, SEL_KPL, 0);
#endif
#else
#error "have you forgotten the isa device?";
#endif

        kdb_init();

#ifdef KDB
        if (boothowto & RB_KDB)
                kdb_enter(KDB_WHY_BOOTFLAGS,
                    "Boot flags requested debugger");
#endif

        identify_cpu();         /* Final stage of CPU initialization */
        initializecpu();        /* Initialize CPU registers */
        initializecpucache();

        /* doublefault stack space, runs on ist1 */
        common_tss[0].tss_ist1 = (long)&dblfault_stack[sizeof(dblfault_stack)];

        /*
         * NMI stack, runs on ist2.  The pcpu pointer is stored just
         * above the start of the ist2 stack.
         */
        np = ((struct nmi_pcpu *) &nmi0_stack[sizeof(nmi0_stack)]) - 1;
        np->np_pcpu = (register_t) pc;
        common_tss[0].tss_ist2 = (long) np;

        /* Set the IO permission bitmap (empty due to tss seg limit) */
        common_tss[0].tss_iobase = sizeof(struct amd64tss) +
            IOPAGES * PAGE_SIZE;

        gsel_tss = GSEL(GPROC0_SEL, SEL_KPL);
        ltr(gsel_tss);

        /* Set up the fast syscall stuff */
        msr = rdmsr(MSR_EFER) | EFER_SCE;
        wrmsr(MSR_EFER, msr);
        wrmsr(MSR_LSTAR, (u_int64_t)IDTVEC(fast_syscall));
        wrmsr(MSR_CSTAR, (u_int64_t)IDTVEC(fast_syscall32));
        msr = ((u_int64_t)GSEL(GCODE_SEL, SEL_KPL) << 32) |
              ((u_int64_t)GSEL(GUCODE32_SEL, SEL_UPL) << 48);
        wrmsr(MSR_STAR, msr);
        wrmsr(MSR_SF_MASK, PSL_NT|PSL_T|PSL_I|PSL_C|PSL_D);

        getmemsize(kmdp, physfree);
        init_param2(physmem);

        /* now running on new page tables, configured,and u/iom is accessible */

        msgbufinit(msgbufp, msgbufsize);
        fpuinit();

        /*
         * Set up thread0 pcb after fpuinit calculated pcb + fpu save
         * area size.  Zero out the extended state header in fpu save
         * area.
         */
        thread0.td_pcb = get_pcb_td(&thread0);
        bzero(get_pcb_user_save_td(&thread0), cpu_max_ext_state_size);
        if (use_xsave) {
                xhdr = (struct xstate_hdr *)(get_pcb_user_save_td(&thread0) +
                    1);
                xhdr->xstate_bv = xsave_mask;
        }
        /* make an initial tss so cpu can get interrupt stack on syscall! */
        common_tss[0].tss_rsp0 = (vm_offset_t)thread0.td_pcb;
        /* Ensure the stack is aligned to 16 bytes */
        common_tss[0].tss_rsp0 &= ~0xFul;
        PCPU_SET(rsp0, common_tss[0].tss_rsp0);
        PCPU_SET(curpcb, thread0.td_pcb);

        /* transfer to user mode */

        _ucodesel = GSEL(GUCODE_SEL, SEL_UPL);
        _udatasel = GSEL(GUDATA_SEL, SEL_UPL);
        _ucode32sel = GSEL(GUCODE32_SEL, SEL_UPL);
        _ufssel = GSEL(GUFS32_SEL, SEL_UPL);
        _ugssel = GSEL(GUGS32_SEL, SEL_UPL);

        load_ds(_udatasel);
        load_es(_udatasel);
        load_fs(_ufssel);

        /* setup proc 0's pcb */
        thread0.td_pcb->pcb_flags = 0;
        thread0.td_pcb->pcb_cr3 = KPML4phys; /* PCID 0 is reserved for kernel */
        thread0.td_frame = &proc0_tf;

        env = getenv("kernelname");
        if (env != NULL)
                strlcpy(kernelname, env, sizeof(kernelname));

        cpu_probe_amdc1e();

#ifdef FDT
        x86_init_fdt();
#endif

        /* Location of kernel stack for locore */
        return ((u_int64_t)thread0.td_pcb);
}

void
cpu_pcpu_init(struct pcpu *pcpu, int cpuid, size_t size)
{

        pcpu->pc_acpi_id = 0xffffffff;
}

void
spinlock_enter(void)
{
        struct thread *td;
        register_t flags;

        td = curthread;
        if (td->td_md.md_spinlock_count == 0) {
                flags = intr_disable();
                td->td_md.md_spinlock_count = 1;
                td->td_md.md_saved_flags = flags;
        } else
                td->td_md.md_spinlock_count++;
        critical_enter();
}

void
spinlock_exit(void)
{
        struct thread *td;
        register_t flags;

        td = curthread;
        critical_exit();
        flags = td->td_md.md_saved_flags;
        td->td_md.md_spinlock_count--;
        if (td->td_md.md_spinlock_count == 0)
                intr_restore(flags);
}

/*
 * Construct a PCB from a trapframe. This is called from kdb_trap() where
 * we want to start a backtrace from the function that caused us to enter
 * the debugger. We have the context in the trapframe, but base the trace
 * on the PCB. The PCB doesn't have to be perfect, as long as it contains
 * enough for a backtrace.
 */
void
makectx(struct trapframe *tf, struct pcb *pcb)
{

        pcb->pcb_r12 = tf->tf_r12;
        pcb->pcb_r13 = tf->tf_r13;
        pcb->pcb_r14 = tf->tf_r14;
        pcb->pcb_r15 = tf->tf_r15;
        pcb->pcb_rbp = tf->tf_rbp;
        pcb->pcb_rbx = tf->tf_rbx;
        pcb->pcb_rip = tf->tf_rip;
        pcb->pcb_rsp = tf->tf_rsp;
}

int
ptrace_set_pc(struct thread *td, unsigned long addr)
{
        td->td_frame->tf_rip = addr;
        return (0);
}

int
ptrace_single_step(struct thread *td)
{
        td->td_frame->tf_rflags |= PSL_T;
        return (0);
}

int
ptrace_clear_single_step(struct thread *td)
{
        td->td_frame->tf_rflags &= ~PSL_T;
        return (0);
}

int
fill_regs(struct thread *td, struct reg *regs)
{
        struct trapframe *tp;

        tp = td->td_frame;
        return (fill_frame_regs(tp, regs));
}

int
fill_frame_regs(struct trapframe *tp, struct reg *regs)
{
        regs->r_r15 = tp->tf_r15;
        regs->r_r14 = tp->tf_r14;
        regs->r_r13 = tp->tf_r13;
        regs->r_r12 = tp->tf_r12;
        regs->r_r11 = tp->tf_r11;
        regs->r_r10 = tp->tf_r10;
        regs->r_r9  = tp->tf_r9;
        regs->r_r8  = tp->tf_r8;
        regs->r_rdi = tp->tf_rdi;
        regs->r_rsi = tp->tf_rsi;
        regs->r_rbp = tp->tf_rbp;
        regs->r_rbx = tp->tf_rbx;
        regs->r_rdx = tp->tf_rdx;
        regs->r_rcx = tp->tf_rcx;
        regs->r_rax = tp->tf_rax;
        regs->r_rip = tp->tf_rip;
        regs->r_cs = tp->tf_cs;
        regs->r_rflags = tp->tf_rflags;
        regs->r_rsp = tp->tf_rsp;
        regs->r_ss = tp->tf_ss;
        if (tp->tf_flags & TF_HASSEGS) {
                regs->r_ds = tp->tf_ds;
                regs->r_es = tp->tf_es;
                regs->r_fs = tp->tf_fs;
                regs->r_gs = tp->tf_gs;
        } else {
                regs->r_ds = 0;
                regs->r_es = 0;
                regs->r_fs = 0;
                regs->r_gs = 0;
        }
        return (0);
}

int
set_regs(struct thread *td, struct reg *regs)
{
        struct trapframe *tp;
        register_t rflags;

        tp = td->td_frame;
        rflags = regs->r_rflags & 0xffffffff;
        if (!EFL_SECURE(rflags, tp->tf_rflags) || !CS_SECURE(regs->r_cs))
                return (EINVAL);
        tp->tf_r15 = regs->r_r15;
        tp->tf_r14 = regs->r_r14;
        tp->tf_r13 = regs->r_r13;
        tp->tf_r12 = regs->r_r12;
        tp->tf_r11 = regs->r_r11;
        tp->tf_r10 = regs->r_r10;
        tp->tf_r9  = regs->r_r9;
        tp->tf_r8  = regs->r_r8;
        tp->tf_rdi = regs->r_rdi;
        tp->tf_rsi = regs->r_rsi;
        tp->tf_rbp = regs->r_rbp;
        tp->tf_rbx = regs->r_rbx;
        tp->tf_rdx = regs->r_rdx;
        tp->tf_rcx = regs->r_rcx;
        tp->tf_rax = regs->r_rax;
        tp->tf_rip = regs->r_rip;
        tp->tf_cs = regs->r_cs;
        tp->tf_rflags = rflags;
        tp->tf_rsp = regs->r_rsp;
        tp->tf_ss = regs->r_ss;
        if (0) {        /* XXXKIB */
                tp->tf_ds = regs->r_ds;
                tp->tf_es = regs->r_es;
                tp->tf_fs = regs->r_fs;
                tp->tf_gs = regs->r_gs;
                tp->tf_flags = TF_HASSEGS;
                set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
        }
        return (0);
}

/* XXX check all this stuff! */
/* externalize from sv_xmm */
static void
fill_fpregs_xmm(struct savefpu *sv_xmm, struct fpreg *fpregs)
{
        struct envxmm *penv_fpreg = (struct envxmm *)&fpregs->fpr_env;
        struct envxmm *penv_xmm = &sv_xmm->sv_env;
        int i;

        /* pcb -> fpregs */
        bzero(fpregs, sizeof(*fpregs));

        /* FPU control/status */
        penv_fpreg->en_cw = penv_xmm->en_cw;
        penv_fpreg->en_sw = penv_xmm->en_sw;
        penv_fpreg->en_tw = penv_xmm->en_tw;
        penv_fpreg->en_opcode = penv_xmm->en_opcode;
        penv_fpreg->en_rip = penv_xmm->en_rip;
        penv_fpreg->en_rdp = penv_xmm->en_rdp;
        penv_fpreg->en_mxcsr = penv_xmm->en_mxcsr;
        penv_fpreg->en_mxcsr_mask = penv_xmm->en_mxcsr_mask;

        /* FPU registers */
        for (i = 0; i < 8; ++i)
                bcopy(sv_xmm->sv_fp[i].fp_acc.fp_bytes, fpregs->fpr_acc[i], 10);

        /* SSE registers */
        for (i = 0; i < 16; ++i)
                bcopy(sv_xmm->sv_xmm[i].xmm_bytes, fpregs->fpr_xacc[i], 16);
}

/* internalize from fpregs into sv_xmm */
static void
set_fpregs_xmm(struct fpreg *fpregs, struct savefpu *sv_xmm)
{
        struct envxmm *penv_xmm = &sv_xmm->sv_env;
        struct envxmm *penv_fpreg = (struct envxmm *)&fpregs->fpr_env;
        int i;

        /* fpregs -> pcb */
        /* FPU control/status */
        penv_xmm->en_cw = penv_fpreg->en_cw;
        penv_xmm->en_sw = penv_fpreg->en_sw;
        penv_xmm->en_tw = penv_fpreg->en_tw;
        penv_xmm->en_opcode = penv_fpreg->en_opcode;
        penv_xmm->en_rip = penv_fpreg->en_rip;
        penv_xmm->en_rdp = penv_fpreg->en_rdp;
        penv_xmm->en_mxcsr = penv_fpreg->en_mxcsr;
        penv_xmm->en_mxcsr_mask = penv_fpreg->en_mxcsr_mask & cpu_mxcsr_mask;

        /* FPU registers */
        for (i = 0; i < 8; ++i)
                bcopy(fpregs->fpr_acc[i], sv_xmm->sv_fp[i].fp_acc.fp_bytes, 10);

        /* SSE registers */
        for (i = 0; i < 16; ++i)
                bcopy(fpregs->fpr_xacc[i], sv_xmm->sv_xmm[i].xmm_bytes, 16);
}

/* externalize from td->pcb */
int
fill_fpregs(struct thread *td, struct fpreg *fpregs)
{

        KASSERT(td == curthread || TD_IS_SUSPENDED(td) ||
            P_SHOULDSTOP(td->td_proc),
            ("not suspended thread %p", td));
        fpugetregs(td);
        fill_fpregs_xmm(get_pcb_user_save_td(td), fpregs);
        return (0);
}

/* internalize to td->pcb */
int
set_fpregs(struct thread *td, struct fpreg *fpregs)
{

        set_fpregs_xmm(fpregs, get_pcb_user_save_td(td));
        fpuuserinited(td);
        return (0);
}

/*
 * Get machine context.
 */
int
get_mcontext(struct thread *td, mcontext_t *mcp, int flags)
{
        struct pcb *pcb;
        struct trapframe *tp;

        pcb = td->td_pcb;
        tp = td->td_frame;
        PROC_LOCK(curthread->td_proc);
        mcp->mc_onstack = sigonstack(tp->tf_rsp);
        PROC_UNLOCK(curthread->td_proc);
        mcp->mc_r15 = tp->tf_r15;
        mcp->mc_r14 = tp->tf_r14;
        mcp->mc_r13 = tp->tf_r13;
        mcp->mc_r12 = tp->tf_r12;
        mcp->mc_r11 = tp->tf_r11;
        mcp->mc_r10 = tp->tf_r10;
        mcp->mc_r9  = tp->tf_r9;
        mcp->mc_r8  = tp->tf_r8;
        mcp->mc_rdi = tp->tf_rdi;
        mcp->mc_rsi = tp->tf_rsi;
        mcp->mc_rbp = tp->tf_rbp;
        mcp->mc_rbx = tp->tf_rbx;
        mcp->mc_rcx = tp->tf_rcx;
        mcp->mc_rflags = tp->tf_rflags;
        if (flags & GET_MC_CLEAR_RET) {
                mcp->mc_rax = 0;
                mcp->mc_rdx = 0;
                mcp->mc_rflags &= ~PSL_C;
        } else {
                mcp->mc_rax = tp->tf_rax;
                mcp->mc_rdx = tp->tf_rdx;
        }
        mcp->mc_rip = tp->tf_rip;
        mcp->mc_cs = tp->tf_cs;
        mcp->mc_rsp = tp->tf_rsp;
        mcp->mc_ss = tp->tf_ss;
        mcp->mc_ds = tp->tf_ds;
        mcp->mc_es = tp->tf_es;
        mcp->mc_fs = tp->tf_fs;
        mcp->mc_gs = tp->tf_gs;
        mcp->mc_flags = tp->tf_flags;
        mcp->mc_len = sizeof(*mcp);
        get_fpcontext(td, mcp, NULL, 0);
        mcp->mc_fsbase = pcb->pcb_fsbase;
        mcp->mc_gsbase = pcb->pcb_gsbase;
        mcp->mc_xfpustate = 0;
        mcp->mc_xfpustate_len = 0;
        bzero(mcp->mc_spare, sizeof(mcp->mc_spare));
        return (0);
}

/*
 * Set machine context.
 *
 * However, we don't set any but the user modifiable flags, and we won't
 * touch the cs selector.
 */
int
set_mcontext(struct thread *td, const mcontext_t *mcp)
{
        struct pcb *pcb;
        struct trapframe *tp;
        char *xfpustate;
        long rflags;
        int ret;

        pcb = td->td_pcb;
        tp = td->td_frame;
        if (mcp->mc_len != sizeof(*mcp) ||
            (mcp->mc_flags & ~_MC_FLAG_MASK) != 0)
                return (EINVAL);
        rflags = (mcp->mc_rflags & PSL_USERCHANGE) |
            (tp->tf_rflags & ~PSL_USERCHANGE);
        if (mcp->mc_flags & _MC_HASFPXSTATE) {
                if (mcp->mc_xfpustate_len > cpu_max_ext_state_size -
                    sizeof(struct savefpu))
                        return (EINVAL);
                xfpustate = __builtin_alloca(mcp->mc_xfpustate_len);
                ret = copyin((void *)mcp->mc_xfpustate, xfpustate,
                    mcp->mc_xfpustate_len);
                if (ret != 0)
                        return (ret);
        } else
                xfpustate = NULL;
        ret = set_fpcontext(td, mcp, xfpustate, mcp->mc_xfpustate_len);
        if (ret != 0)
                return (ret);
        tp->tf_r15 = mcp->mc_r15;
        tp->tf_r14 = mcp->mc_r14;
        tp->tf_r13 = mcp->mc_r13;
        tp->tf_r12 = mcp->mc_r12;
        tp->tf_r11 = mcp->mc_r11;
        tp->tf_r10 = mcp->mc_r10;
        tp->tf_r9  = mcp->mc_r9;
        tp->tf_r8  = mcp->mc_r8;
        tp->tf_rdi = mcp->mc_rdi;
        tp->tf_rsi = mcp->mc_rsi;
        tp->tf_rbp = mcp->mc_rbp;
        tp->tf_rbx = mcp->mc_rbx;
        tp->tf_rdx = mcp->mc_rdx;
        tp->tf_rcx = mcp->mc_rcx;
        tp->tf_rax = mcp->mc_rax;
        tp->tf_rip = mcp->mc_rip;
        tp->tf_rflags = rflags;
        tp->tf_rsp = mcp->mc_rsp;
        tp->tf_ss = mcp->mc_ss;
        tp->tf_flags = mcp->mc_flags;
        if (tp->tf_flags & TF_HASSEGS) {
                tp->tf_ds = mcp->mc_ds;
                tp->tf_es = mcp->mc_es;
                tp->tf_fs = mcp->mc_fs;
                tp->tf_gs = mcp->mc_gs;
        }
        if (mcp->mc_flags & _MC_HASBASES) {
                pcb->pcb_fsbase = mcp->mc_fsbase;
                pcb->pcb_gsbase = mcp->mc_gsbase;
        }
        set_pcb_flags(pcb, PCB_FULL_IRET);
        return (0);
}

static void
get_fpcontext(struct thread *td, mcontext_t *mcp, char *xfpusave,
    size_t xfpusave_len)
{
        size_t max_len, len;

        mcp->mc_ownedfp = fpugetregs(td);
        bcopy(get_pcb_user_save_td(td), &mcp->mc_fpstate[0],
            sizeof(mcp->mc_fpstate));
        mcp->mc_fpformat = fpuformat();
        if (!use_xsave || xfpusave_len == 0)
                return;
        max_len = cpu_max_ext_state_size - sizeof(struct savefpu);
        len = xfpusave_len;
        if (len > max_len) {
                len = max_len;
                bzero(xfpusave + max_len, len - max_len);
        }
        mcp->mc_flags |= _MC_HASFPXSTATE;
        mcp->mc_xfpustate_len = len;
        bcopy(get_pcb_user_save_td(td) + 1, xfpusave, len);
}

static int
set_fpcontext(struct thread *td, const mcontext_t *mcp, char *xfpustate,
    size_t xfpustate_len)
{
        struct savefpu *fpstate;
        int error;

        if (mcp->mc_fpformat == _MC_FPFMT_NODEV)
                return (0);
        else if (mcp->mc_fpformat != _MC_FPFMT_XMM)
                return (EINVAL);
        else if (mcp->mc_ownedfp == _MC_FPOWNED_NONE) {
                /* We don't care what state is left in the FPU or PCB. */
                fpstate_drop(td);
                error = 0;
        } else if (mcp->mc_ownedfp == _MC_FPOWNED_FPU ||
            mcp->mc_ownedfp == _MC_FPOWNED_PCB) {
                fpstate = (struct savefpu *)&mcp->mc_fpstate;
                fpstate->sv_env.en_mxcsr &= cpu_mxcsr_mask;
                error = fpusetregs(td, fpstate, xfpustate, xfpustate_len);
        } else
                return (EINVAL);
        return (error);
}

void
fpstate_drop(struct thread *td)
{

        KASSERT(PCB_USER_FPU(td->td_pcb), ("fpstate_drop: kernel-owned fpu"));
        critical_enter();
        if (PCPU_GET(fpcurthread) == td)
                fpudrop();
        /*
         * XXX force a full drop of the fpu.  The above only drops it if we
         * owned it.
         *
         * XXX I don't much like fpugetuserregs()'s semantics of doing a full
         * drop.  Dropping only to the pcb matches fnsave's behaviour.
         * We only need to drop to !PCB_INITDONE in sendsig().  But
         * sendsig() is the only caller of fpugetuserregs()... perhaps we just
         * have too many layers.
         */
        clear_pcb_flags(curthread->td_pcb,
            PCB_FPUINITDONE | PCB_USERFPUINITDONE);
        critical_exit();
}

int
fill_dbregs(struct thread *td, struct dbreg *dbregs)
{
        struct pcb *pcb;

        if (td == NULL) {
                dbregs->dr[0] = rdr0();
                dbregs->dr[1] = rdr1();
                dbregs->dr[2] = rdr2();
                dbregs->dr[3] = rdr3();
                dbregs->dr[6] = rdr6();
                dbregs->dr[7] = rdr7();
        } else {
                pcb = td->td_pcb;
                dbregs->dr[0] = pcb->pcb_dr0;
                dbregs->dr[1] = pcb->pcb_dr1;
                dbregs->dr[2] = pcb->pcb_dr2;
                dbregs->dr[3] = pcb->pcb_dr3;
                dbregs->dr[6] = pcb->pcb_dr6;
                dbregs->dr[7] = pcb->pcb_dr7;
        }
        dbregs->dr[4] = 0;
        dbregs->dr[5] = 0;
        dbregs->dr[8] = 0;
        dbregs->dr[9] = 0;
        dbregs->dr[10] = 0;
        dbregs->dr[11] = 0;
        dbregs->dr[12] = 0;
        dbregs->dr[13] = 0;
        dbregs->dr[14] = 0;
        dbregs->dr[15] = 0;
        return (0);
}

int
set_dbregs(struct thread *td, struct dbreg *dbregs)
{
        struct pcb *pcb;
        int i;

        if (td == NULL) {
                load_dr0(dbregs->dr[0]);
                load_dr1(dbregs->dr[1]);
                load_dr2(dbregs->dr[2]);
                load_dr3(dbregs->dr[3]);
                load_dr6(dbregs->dr[6]);
                load_dr7(dbregs->dr[7]);
        } else {
                /*
                 * Don't let an illegal value for dr7 get set.  Specifically,
                 * check for undefined settings.  Setting these bit patterns
                 * result in undefined behaviour and can lead to an unexpected
                 * TRCTRAP or a general protection fault right here.
                 * Upper bits of dr6 and dr7 must not be set
                 */
                for (i = 0; i < 4; i++) {
                        if (DBREG_DR7_ACCESS(dbregs->dr[7], i) == 0x02)
                                return (EINVAL);
                        if (td->td_frame->tf_cs == _ucode32sel &&
                            DBREG_DR7_LEN(dbregs->dr[7], i) == DBREG_DR7_LEN_8)
                                return (EINVAL);
                }
                if ((dbregs->dr[6] & 0xffffffff00000000ul) != 0 ||
                    (dbregs->dr[7] & 0xffffffff00000000ul) != 0)
                        return (EINVAL);

                pcb = td->td_pcb;

                /*
                 * Don't let a process set a breakpoint that is not within the
                 * process's address space.  If a process could do this, it
                 * could halt the system by setting a breakpoint in the kernel
                 * (if ddb was enabled).  Thus, we need to check to make sure
                 * that no breakpoints are being enabled for addresses outside
                 * process's address space.
                 *
                 * XXX - what about when the watched area of the user's
                 * address space is written into from within the kernel
                 * ... wouldn't that still cause a breakpoint to be generated
                 * from within kernel mode?
                 */

                if (DBREG_DR7_ENABLED(dbregs->dr[7], 0)) {
                        /* dr0 is enabled */
                        if (dbregs->dr[0] >= VM_MAXUSER_ADDRESS)
                                return (EINVAL);
                }
                if (DBREG_DR7_ENABLED(dbregs->dr[7], 1)) {
                        /* dr1 is enabled */
                        if (dbregs->dr[1] >= VM_MAXUSER_ADDRESS)
                                return (EINVAL);
                }
                if (DBREG_DR7_ENABLED(dbregs->dr[7], 2)) {
                        /* dr2 is enabled */
                        if (dbregs->dr[2] >= VM_MAXUSER_ADDRESS)
                                return (EINVAL);
                }
                if (DBREG_DR7_ENABLED(dbregs->dr[7], 3)) {
                        /* dr3 is enabled */
                        if (dbregs->dr[3] >= VM_MAXUSER_ADDRESS)
                                return (EINVAL);
                }

                pcb->pcb_dr0 = dbregs->dr[0];
                pcb->pcb_dr1 = dbregs->dr[1];
                pcb->pcb_dr2 = dbregs->dr[2];
                pcb->pcb_dr3 = dbregs->dr[3];
                pcb->pcb_dr6 = dbregs->dr[6];
                pcb->pcb_dr7 = dbregs->dr[7];

                set_pcb_flags(pcb, PCB_DBREGS);
        }

        return (0);
}

void
reset_dbregs(void)
{

        load_dr7(0);    /* Turn off the control bits first */
        load_dr0(0);
        load_dr1(0);
        load_dr2(0);
        load_dr3(0);
        load_dr6(0);
}

/*
 * Return > 0 if a hardware breakpoint has been hit, and the
 * breakpoint was in user space.  Return 0, otherwise.
 */
int
user_dbreg_trap(void)
{
        u_int64_t dr7, dr6; /* debug registers dr6 and dr7 */
        u_int64_t bp;       /* breakpoint bits extracted from dr6 */
        int nbp;            /* number of breakpoints that triggered */
        caddr_t addr[4];    /* breakpoint addresses */
        int i;
        
        dr7 = rdr7();
        if ((dr7 & 0x000000ff) == 0) {
                /*
                 * all GE and LE bits in the dr7 register are zero,
                 * thus the trap couldn't have been caused by the
                 * hardware debug registers
                 */
                return 0;
        }

        nbp = 0;
        dr6 = rdr6();
        bp = dr6 & 0x0000000f;

        if (!bp) {
                /*
                 * None of the breakpoint bits are set meaning this
                 * trap was not caused by any of the debug registers
                 */
                return 0;
        }

        /*
         * at least one of the breakpoints were hit, check to see
         * which ones and if any of them are user space addresses
         */

        if (bp & 0x01) {
                addr[nbp++] = (caddr_t)rdr0();
        }
        if (bp & 0x02) {
                addr[nbp++] = (caddr_t)rdr1();
        }
        if (bp & 0x04) {
                addr[nbp++] = (caddr_t)rdr2();
        }
        if (bp & 0x08) {
                addr[nbp++] = (caddr_t)rdr3();
        }

        for (i = 0; i < nbp; i++) {
                if (addr[i] < (caddr_t)VM_MAXUSER_ADDRESS) {
                        /*
                         * addr[i] is in user space
                         */
                        return nbp;
                }
        }

        /*
         * None of the breakpoints are in user space.
         */
        return 0;
}

#ifdef KDB

/*
 * Provide inb() and outb() as functions.  They are normally only available as
 * inline functions, thus cannot be called from the debugger.
 */

/* silence compiler warnings */
u_char inb_(u_short);
void outb_(u_short, u_char);

u_char
inb_(u_short port)
{
        return inb(port);
}

void
outb_(u_short port, u_char data)
{
        outb(port, data);
}

#endif /* KDB */