[apple/xnu.git] / osfmk / i386 / mp_desc.c

/*
 * Copyright (c) 2000-2009 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */

/*
 */

#include <kern/cpu_number.h>
#include <kern/kalloc.h>
#include <kern/cpu_data.h>
#include <mach/mach_types.h>
#include <mach/machine.h>
#include <kern/etimer.h>
#include <mach/vm_map.h>
#include <mach/machine/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_map.h>

#include <i386/lock.h>
#include <i386/mp_desc.h>
#include <i386/misc_protos.h>
#include <i386/mp.h>
#include <i386/pmap.h>
#if defined(__i386__)
#include <i386/pmap_internal.h>
#endif /* i386 */
#if CONFIG_MCA
#include <i386/machine_check.h>
#endif

#include <kern/misc_protos.h>

#ifdef __x86_64__
#define K_INTR_GATE (ACC_P|ACC_PL_K|ACC_INTR_GATE)
#define U_INTR_GATE (ACC_P|ACC_PL_U|ACC_INTR_GATE)

// Declare macros that will declare the externs
#define TRAP(n, name)           extern void *name ;
#define TRAP_ERR(n, name)       extern void *name ;
#define TRAP_SPC(n, name)       extern void *name ;
#define TRAP_IST(n, name)       extern void *name ;
#define INTERRUPT(n)            extern void *_intr_ ## n ;
#define USER_TRAP(n, name)      extern void *name ;
#define USER_TRAP_SPC(n, name)  extern void *name ;

// Include the table to declare the externs
#include "../x86_64/idt_table.h"

// Undef the macros, then redefine them so we can declare the table
#undef TRAP
#undef TRAP_ERR
#undef TRAP_SPC
#undef TRAP_IST
#undef INTERRUPT
#undef USER_TRAP
#undef USER_TRAP_SPC

#define TRAP(n, name)                   \
        [n] = {                         \
                (uintptr_t)&name,       \
                KERNEL64_CS,            \
                0,                      \
                K_INTR_GATE,            \
                0                       \
        },

#define TRAP_ERR TRAP
#define TRAP_SPC TRAP

#define TRAP_IST(n, name) \
        [n] = {                         \
                (uintptr_t)&name,       \
                KERNEL64_CS,            \
                1,                      \
                K_INTR_GATE,            \
                0                       \
        },

#define INTERRUPT(n) \
        [n] = {                         \
                (uintptr_t)&_intr_ ## n,\
                KERNEL64_CS,            \
                0,                      \
                K_INTR_GATE,            \
                0                       \
        },

#define USER_TRAP(n, name) \
        [n] = {                         \
                (uintptr_t)&name,       \
                KERNEL64_CS,            \
                0,                      \
                U_INTR_GATE,            \
                0                       \
        },

#define USER_TRAP_SPC USER_TRAP

// Declare the table using the macros we just set up
struct fake_descriptor64 master_idt64[IDTSZ]
        __attribute__ ((section("__HIB,__desc")))
        __attribute__ ((aligned(PAGE_SIZE))) = {
#include "../x86_64/idt_table.h"
};
#endif

/*
 * The i386 needs an interrupt stack to keep the PCB stack from being
 * overrun by interrupts.  All interrupt stacks MUST lie at lower addresses
 * than any thread`s kernel stack.
 */

/*
 * First cpu`s interrupt stack.
 */
extern uint32_t         low_intstack[];         /* bottom */
extern uint32_t         low_eintstack[];        /* top */

/*
 * Per-cpu data area pointers.
 * The master cpu (cpu 0) has its data area statically allocated;
 * others are allocated dynamically and this array is updated at runtime.
 */
cpu_data_t      cpu_data_master = {
        .cpu_this = &cpu_data_master,
        .cpu_nanotime = &pal_rtc_nanotime_info,
        .cpu_int_stack_top = (vm_offset_t) low_eintstack,
#ifdef __i386__
        .cpu_is64bit = FALSE,
#else
        .cpu_is64bit = TRUE
#endif
};
cpu_data_t      *cpu_data_ptr[MAX_CPUS] = { [0] = &cpu_data_master };

decl_simple_lock_data(,ncpus_lock);     /* protects real_ncpus */
unsigned int    real_ncpus = 1;
unsigned int    max_ncpus = MAX_CPUS;

#ifdef __i386__
extern void *hi_remap_text;
#define HI_TEXT(lo_text)        \
        (((uint32_t)&lo_text - (uint32_t)&hi_remap_text) + HIGH_MEM_BASE)

extern void hi_sysenter(void);

typedef struct {
        uint16_t        length;
        uint32_t        offset[2];
} __attribute__((__packed__)) table_descriptor64_t;

extern  table_descriptor64_t    gdtptr64;
extern  table_descriptor64_t    idtptr64;
#endif
extern void hi64_sysenter(void);
extern void hi64_syscall(void);

#if defined(__x86_64__) && !defined(UBER64)
#define UBER64(x) ((uintptr_t)x)
#endif

/*
 * Multiprocessor i386/i486 systems use a separate copy of the
 * GDT, IDT, LDT, and kernel TSS per processor.  The first three
 * are separate to avoid lock contention: the i386 uses locked
 * memory cycles to access the descriptor tables.  The TSS is
 * separate since each processor needs its own kernel stack,
 * and since using a TSS marks it busy.
 */

/*
 * Allocate and initialize the per-processor descriptor tables.
 */

struct fake_descriptor ldt_desc_pattern = {
        (unsigned int) 0,
        LDTSZ_MIN * sizeof(struct fake_descriptor) - 1,
        0,
        ACC_P|ACC_PL_K|ACC_LDT
};

struct fake_descriptor tss_desc_pattern = {
        (unsigned int) 0,
        sizeof(struct i386_tss) - 1,
        0,
        ACC_P|ACC_PL_K|ACC_TSS
};

struct fake_descriptor cpudata_desc_pattern = {
        (unsigned int) 0,
        sizeof(cpu_data_t)-1,
        SZ_32,
        ACC_P|ACC_PL_K|ACC_DATA_W
};

#if     NCOPY_WINDOWS > 0
struct fake_descriptor userwindow_desc_pattern = {
        (unsigned int) 0,
        ((NBPDE * NCOPY_WINDOWS) / PAGE_SIZE) - 1,
        SZ_32 | SZ_G,
        ACC_P|ACC_PL_U|ACC_DATA_W
};
#endif

struct fake_descriptor physwindow_desc_pattern = {
        (unsigned int) 0,
        PAGE_SIZE - 1,
        SZ_32,
        ACC_P|ACC_PL_K|ACC_DATA_W
};

/*
 * This is the expanded, 64-bit variant of the kernel LDT descriptor.
 * When switching to 64-bit mode this replaces KERNEL_LDT entry
 * and the following empty slot. This enables the LDT to be referenced
 * in the uber-space remapping window on the kernel.
 */
struct fake_descriptor64 kernel_ldt_desc64 = {
        0,
        LDTSZ_MIN*sizeof(struct fake_descriptor)-1,
        0,
        ACC_P|ACC_PL_K|ACC_LDT,
        0
};

/*
 * This is the expanded, 64-bit variant of the kernel TSS descriptor.
 * It is follows pattern of the KERNEL_LDT.
 */
struct fake_descriptor64 kernel_tss_desc64 = {
        0,
        sizeof(struct x86_64_tss)-1,
        0,
        ACC_P|ACC_PL_K|ACC_TSS,
        0
};

/*
 * Convert a descriptor from fake to real format.
 *
 * Fake descriptor format:
 *      bytes 0..3              base 31..0
 *      bytes 4..5              limit 15..0
 *      byte  6                 access byte 2 | limit 19..16
 *      byte  7                 access byte 1
 *
 * Real descriptor format:
 *      bytes 0..1              limit 15..0
 *      bytes 2..3              base 15..0
 *      byte  4                 base 23..16
 *      byte  5                 access byte 1
 *      byte  6                 access byte 2 | limit 19..16
 *      byte  7                 base 31..24
 *
 * Fake gate format:
 *      bytes 0..3              offset
 *      bytes 4..5              selector
 *      byte  6                 word count << 4 (to match fake descriptor)
 *      byte  7                 access byte 1
 *
 * Real gate format:
 *      bytes 0..1              offset 15..0
 *      bytes 2..3              selector
 *      byte  4                 word count
 *      byte  5                 access byte 1
 *      bytes 6..7              offset 31..16
 */
void
fix_desc(void *d, int num_desc) {
        //early_kprintf("fix_desc(%x, %x)\n", d, num_desc);
        uint8_t *desc = (uint8_t*) d;

        do {
                if ((desc[7] & 0x14) == 0x04) { /* gate */
                        uint32_t offset;
                        uint16_t selector;
                        uint8_t wordcount;
                        uint8_t acc;
                        
                        offset = *((uint32_t*)(desc));
                        selector = *((uint32_t*)(desc+4));
                        wordcount = desc[6] >> 4;
                        acc = desc[7];

                        *((uint16_t*)desc) = offset & 0xFFFF;
                        *((uint16_t*)(desc+2)) = selector;
                        desc[4] = wordcount;
                        desc[5] = acc;
                        *((uint16_t*)(desc+6)) = offset >> 16;

                } else { /* descriptor */
                        uint32_t base;
                        uint16_t limit;
                        uint8_t acc1, acc2;

                        base = *((uint32_t*)(desc));
                        limit = *((uint16_t*)(desc+4));
                        acc2 = desc[6];
                        acc1 = desc[7];

                        *((uint16_t*)(desc)) = limit;
                        *((uint16_t*)(desc+2)) = base & 0xFFFF;
                        desc[4] = (base >> 16) & 0xFF;
                        desc[5] = acc1;
                        desc[6] = acc2;
                        desc[7] = base >> 24;
                }
                desc += 8;
        } while (--num_desc);
}

void
fix_desc64(void *descp, int count)
{
        struct fake_descriptor64        *fakep;
        union {
                struct real_gate64              gate;
                struct real_descriptor64        desc;
        }                               real;
        int                             i;

        fakep = (struct fake_descriptor64 *) descp;
        
        for (i = 0; i < count; i++, fakep++) {
                /*
                 * Construct the real decriptor locally.
                 */

                bzero((void *) &real, sizeof(real));

                switch (fakep->access & ACC_TYPE) {
                case 0:
                        break;
                case ACC_CALL_GATE:
                case ACC_INTR_GATE:
                case ACC_TRAP_GATE:
                        real.gate.offset_low16 = (uint16_t)(fakep->offset64 & 0xFFFF);
                        real.gate.selector16 = fakep->lim_or_seg & 0xFFFF;
                        real.gate.IST = fakep->size_or_IST & 0x7;
                        real.gate.access8 = fakep->access;
                        real.gate.offset_high16 = (uint16_t)((fakep->offset64>>16) & 0xFFFF);
                        real.gate.offset_top32 = (uint32_t)(fakep->offset64>>32);
                        break;
                default:        /* Otherwise */
                        real.desc.limit_low16 = fakep->lim_or_seg & 0xFFFF;
                        real.desc.base_low16 = (uint16_t)(fakep->offset64 & 0xFFFF);
                        real.desc.base_med8 = (uint8_t)((fakep->offset64 >> 16) & 0xFF);
                        real.desc.access8 = fakep->access;
                        real.desc.limit_high4 = (fakep->lim_or_seg >> 16) & 0xFF;
                        real.desc.granularity4 = fakep->size_or_IST;
                        real.desc.base_high8 = (uint8_t)((fakep->offset64 >> 24) & 0xFF);
                        real.desc.base_top32 = (uint32_t)(fakep->offset64>>32);
                }

                /*
                 * Now copy back over the fake structure.
                 */
                bcopy((void *) &real, (void *) fakep, sizeof(real));
        }
}

#ifdef __i386__
void
cpu_desc_init(cpu_data_t *cdp)
{
        cpu_desc_index_t        *cdi = &cdp->cpu_desc_index;

        if (cdp == &cpu_data_master) {
                /*
                 * Fix up the entries in the GDT to point to
                 * this LDT and this TSS.
                 */
                struct fake_descriptor temp_fake_desc;
                temp_fake_desc = ldt_desc_pattern;
                temp_fake_desc.offset = (vm_offset_t) &master_ldt;
                fix_desc(&temp_fake_desc, 1);
                *(struct fake_descriptor *) &master_gdt[sel_idx(KERNEL_LDT)] =
                        temp_fake_desc;
                *(struct fake_descriptor *) &master_gdt[sel_idx(USER_LDT)] =
                        temp_fake_desc;

                temp_fake_desc = tss_desc_pattern;
                temp_fake_desc.offset = (vm_offset_t) &master_ktss;
                fix_desc(&temp_fake_desc, 1);
                *(struct fake_descriptor *) &master_gdt[sel_idx(KERNEL_TSS)] =
                        temp_fake_desc;

                temp_fake_desc = cpudata_desc_pattern;
                temp_fake_desc.offset = (vm_offset_t) &cpu_data_master;
                fix_desc(&temp_fake_desc, 1);
                *(struct fake_descriptor *) &master_gdt[sel_idx(CPU_DATA_GS)] =
                        temp_fake_desc;

                fix_desc((void *)&master_idt, IDTSZ);

                cdi->cdi_idt.ptr = master_idt;
                cdi->cdi_gdt.ptr = (void *)master_gdt;


                /*
                 * Master CPU uses the tables built at boot time.
                 * Just set the index pointers to the high shared-mapping space.
                 * Note that the sysenter stack uses empty space above the ktss
                 * in the HIGH_FIXED_KTSS page. In this case we don't map the
                 * the real master_sstk in low memory.
                 */
                cdi->cdi_ktss = (struct i386_tss *)
                        pmap_index_to_virt(HIGH_FIXED_KTSS) ;
                cdi->cdi_sstk = (vm_offset_t) (cdi->cdi_ktss + 1) +
                                (vm_offset_t) &master_sstk.top -
                                (vm_offset_t) &master_sstk;
        } else {
                cpu_desc_table_t        *cdt = (cpu_desc_table_t *) cdp->cpu_desc_tablep;

                vm_offset_t     cpu_hi_desc;

                cpu_hi_desc = pmap_cpu_high_shared_remap(
                                        cdp->cpu_number,
                                        HIGH_CPU_DESC,
                                        (vm_offset_t) cdt, 1);

                /*
                 * Per-cpu GDT, IDT, LDT, KTSS descriptors are allocated in one
                 * block (cpu_desc_table) and double-mapped into high shared space
                 * in one page window.
                 * Also, a transient stack for the fast sysenter path. The top of
                 * which is set at context switch time to point to the PCB using
                 * the high address.
                 */
                cdi->cdi_gdt.ptr  = (struct fake_descriptor *) (cpu_hi_desc +
                                        offsetof(cpu_desc_table_t, gdt[0]));
                cdi->cdi_idt.ptr  = (struct fake_descriptor *) (cpu_hi_desc +
                                        offsetof(cpu_desc_table_t, idt[0]));
                cdi->cdi_ktss = (struct i386_tss *) (cpu_hi_desc +
                                        offsetof(cpu_desc_table_t, ktss));
                cdi->cdi_sstk = cpu_hi_desc + offsetof(cpu_desc_table_t, sstk.top);

                /*
                 * LDT descriptors are mapped into a seperate area.
                 */
                cdi->cdi_ldt  = (struct fake_descriptor *)
                                pmap_cpu_high_shared_remap(
                                        cdp->cpu_number,
                                        HIGH_CPU_LDT_BEGIN,
                                        (vm_offset_t) cdp->cpu_ldtp,
                                        HIGH_CPU_LDT_END - HIGH_CPU_LDT_BEGIN + 1);

                /*
                 * Copy the tables
                 */
                bcopy((char *)master_idt, (char *)cdt->idt, sizeof(master_idt));
                bcopy((char *)master_gdt, (char *)cdt->gdt, sizeof(master_gdt));
                bcopy((char *)master_ldt, (char *)cdp->cpu_ldtp, sizeof(master_ldt));
                bzero((char *)&cdt->ktss, sizeof(struct i386_tss)); 

                /*
                 * Fix up the entries in the GDT to point to
                 * this LDT and this TSS.
                 */
                struct fake_descriptor temp_ldt = ldt_desc_pattern;
                temp_ldt.offset = (vm_offset_t)cdi->cdi_ldt;
                fix_desc(&temp_ldt, 1);

                cdt->gdt[sel_idx(KERNEL_LDT)] = temp_ldt;
                cdt->gdt[sel_idx(USER_LDT)] = temp_ldt;

                cdt->gdt[sel_idx(KERNEL_TSS)] = tss_desc_pattern;
                cdt->gdt[sel_idx(KERNEL_TSS)].offset = (vm_offset_t) cdi->cdi_ktss;
                fix_desc(&cdt->gdt[sel_idx(KERNEL_TSS)], 1);

                cdt->gdt[sel_idx(CPU_DATA_GS)] = cpudata_desc_pattern;
                cdt->gdt[sel_idx(CPU_DATA_GS)].offset = (vm_offset_t) cdp;
                fix_desc(&cdt->gdt[sel_idx(CPU_DATA_GS)], 1);

                cdt->ktss.ss0 = KERNEL_DS;
                cdt->ktss.io_bit_map_offset = 0x0FFF;   /* no IO bitmap */

                cpu_userwindow_init(cdp->cpu_number);
                cpu_physwindow_init(cdp->cpu_number);

        }
}
#endif /* __i386__ */

void
cpu_desc_init64(cpu_data_t *cdp)
{
        cpu_desc_index_t        *cdi = &cdp->cpu_desc_index;

        if (cdp == &cpu_data_master) {
                /*
                 * Master CPU uses the tables built at boot time.
                 * Just set the index pointers to the low memory space.
                 */
                cdi->cdi_ktss = (void *)&master_ktss64;
                cdi->cdi_sstk = (vm_offset_t) &master_sstk.top;
#if __x86_64__
                cdi->cdi_gdt.ptr  = (void *)MASTER_GDT_ALIAS;
                cdi->cdi_idt.ptr  = (void *)MASTER_IDT_ALIAS;
#else
                cdi->cdi_gdt.ptr  = (void *)master_gdt;
                cdi->cdi_idt.ptr  = (void *)master_idt64;
#endif
                cdi->cdi_ldt  = (struct fake_descriptor *) master_ldt;

                /* Replace the expanded LDTs and TSS slots in the GDT */
                kernel_ldt_desc64.offset64 = UBER64(&master_ldt);
                *(struct fake_descriptor64 *) &master_gdt[sel_idx(KERNEL_LDT)] =
                        kernel_ldt_desc64;
                *(struct fake_descriptor64 *) &master_gdt[sel_idx(USER_LDT)] =
                        kernel_ldt_desc64;
                kernel_tss_desc64.offset64 = UBER64(&master_ktss64);
                *(struct fake_descriptor64 *) &master_gdt[sel_idx(KERNEL_TSS)] =
                        kernel_tss_desc64;

                /* Fix up the expanded descriptors for 64-bit. */
                fix_desc64((void *) &master_idt64, IDTSZ);
                fix_desc64((void *) &master_gdt[sel_idx(KERNEL_LDT)], 1);
                fix_desc64((void *) &master_gdt[sel_idx(USER_LDT)], 1);
                fix_desc64((void *) &master_gdt[sel_idx(KERNEL_TSS)], 1);

                /*
                 * Set the double-fault stack as IST1 in the 64-bit TSS
                 */
#if __x86_64__
                master_ktss64.ist1 = (uintptr_t) low_eintstack;
#else
                master_ktss64.ist1 = UBER64((uintptr_t) df_task_stack_end);
#endif

        } else {
                cpu_desc_table64_t      *cdt = (cpu_desc_table64_t *) cdp->cpu_desc_tablep;
                /*
                 * Per-cpu GDT, IDT, KTSS descriptors are allocated in kernel 
                 * heap (cpu_desc_table). 
                 * LDT descriptors are mapped into a separate area.
                 */
#if __x86_64__
                cdi->cdi_idt.ptr  = (void *)MASTER_IDT_ALIAS;
#else
                cdi->cdi_idt.ptr  = (void *)cdt->idt;
#endif
                cdi->cdi_gdt.ptr  = (struct fake_descriptor *)cdt->gdt;
                cdi->cdi_ktss = (void *)&cdt->ktss;
                cdi->cdi_sstk = (vm_offset_t)&cdt->sstk.top;
                cdi->cdi_ldt  = cdp->cpu_ldtp;

                /*
                 * Copy the tables
                 */
#if !__x86_64__
                bcopy((char *)master_idt64, (char *)cdt->idt, sizeof(master_idt64));
#endif
                bcopy((char *)master_gdt, (char *)cdt->gdt, sizeof(master_gdt));
                bcopy((char *)master_ldt, (char *)cdp->cpu_ldtp, sizeof(master_ldt));
                bcopy((char *)&master_ktss64, (char *)&cdt->ktss, sizeof(struct x86_64_tss));

                /*
                 * Fix up the entries in the GDT to point to
                 * this LDT and this TSS.
                 */
                kernel_ldt_desc64.offset64 = UBER64(cdi->cdi_ldt);
                *(struct fake_descriptor64 *) &cdt->gdt[sel_idx(KERNEL_LDT)] =
                        kernel_ldt_desc64;
                fix_desc64(&cdt->gdt[sel_idx(KERNEL_LDT)], 1);

                kernel_ldt_desc64.offset64 = UBER64(cdi->cdi_ldt);
                *(struct fake_descriptor64 *) &cdt->gdt[sel_idx(USER_LDT)] =
                        kernel_ldt_desc64;
                fix_desc64(&cdt->gdt[sel_idx(USER_LDT)], 1);

                kernel_tss_desc64.offset64 = UBER64(cdi->cdi_ktss);
                *(struct fake_descriptor64 *) &cdt->gdt[sel_idx(KERNEL_TSS)] =
                        kernel_tss_desc64;
                fix_desc64(&cdt->gdt[sel_idx(KERNEL_TSS)], 1);

                /* Set (zeroed) double-fault stack as IST1 */
                bzero((void *) cdt->dfstk, sizeof(cdt->dfstk));
                cdt->ktss.ist1 = UBER64((unsigned long)cdt->dfstk + sizeof(cdt->dfstk));
#ifdef __i386__
                cdt->gdt[sel_idx(CPU_DATA_GS)] = cpudata_desc_pattern;
                cdt->gdt[sel_idx(CPU_DATA_GS)].offset = (vm_offset_t) cdp;
                fix_desc(&cdt->gdt[sel_idx(CPU_DATA_GS)], 1);

                /* Allocate copyio windows */
                cpu_userwindow_init(cdp->cpu_number);
                cpu_physwindow_init(cdp->cpu_number);
#endif
        }

        /* Require that the top of the sysenter stack is 16-byte aligned */
        if ((cdi->cdi_sstk % 16) != 0)
                panic("cpu_desc_init64() sysenter stack not 16-byte aligned");
}

#ifdef __i386__
void
cpu_desc_load(cpu_data_t *cdp)
{
        cpu_desc_index_t        *cdi = &cdp->cpu_desc_index;

        cdi->cdi_idt.size = 0x1000 + cdp->cpu_number;
        cdi->cdi_gdt.size = sizeof(struct real_descriptor)*GDTSZ - 1;

        lgdt((uintptr_t *) &cdi->cdi_gdt);
        lidt((uintptr_t *) &cdi->cdi_idt);
        lldt(KERNEL_LDT);

        set_tr(KERNEL_TSS);

        __asm__ volatile("mov %0, %%gs" : : "rm" ((unsigned short)(CPU_DATA_GS)));
}
#endif /* __i386__ */

void
cpu_desc_load64(cpu_data_t *cdp)
{
        cpu_desc_index_t        *cdi = &cdp->cpu_desc_index;

#ifdef __i386__
        /*
         * Load up the new descriptors etc
         * ml_load_desc64() expects these global pseudo-descriptors:
         *   gdtptr64 -> per-cpu gdt
         *   idtptr64 -> per-cpu idt
         * These are 10-byte descriptors with 64-bit addresses into
         * uber-space.
         *
         * Refer to commpage/cpu_number.s for the IDT limit trick.
         */
        gdtptr64.length = GDTSZ * sizeof(struct real_descriptor) - 1;
        gdtptr64.offset[0] = (uint32_t) cdi->cdi_gdt.ptr;
        gdtptr64.offset[1] = KERNEL_UBER_BASE_HI32;
        idtptr64.length = 0x1000 + cdp->cpu_number;
        idtptr64.offset[0] = (uint32_t) cdi->cdi_idt.ptr;
        idtptr64.offset[1] = KERNEL_UBER_BASE_HI32;

        /* Make sure busy bit is cleared in the TSS */
        gdt_desc_p(KERNEL_TSS)->access &= ~ACC_TSS_BUSY;

        ml_load_desc64();
#else
        /* Load the GDT, LDT, IDT and TSS */
        cdi->cdi_gdt.size = sizeof(struct real_descriptor)*GDTSZ - 1;
        cdi->cdi_idt.size = 0x1000 + cdp->cpu_number;
        lgdt((uintptr_t *) &cdi->cdi_gdt);
        lidt((uintptr_t *) &cdi->cdi_idt);
        lldt(KERNEL_LDT);
        set_tr(KERNEL_TSS);

        /* Stuff the kernel per-cpu data area address into the MSRs */
        wrmsr64(MSR_IA32_GS_BASE, (uintptr_t) cdp);
        wrmsr64(MSR_IA32_KERNEL_GS_BASE, (uintptr_t) cdp);

#if GPROF // Hack to enable mcount to work on K64
        __asm__ volatile("mov %0, %%gs" : : "rm" ((unsigned short)(KERNEL_DS)));
#endif
#endif
}

#ifdef __i386__
/*
 * Set MSRs for sysenter/sysexit for 32-bit.
 */
static void
fast_syscall_init(__unused cpu_data_t *cdp)
{
        wrmsr(MSR_IA32_SYSENTER_CS, SYSENTER_CS, 0); 
        wrmsr(MSR_IA32_SYSENTER_EIP, HI_TEXT(hi_sysenter), 0);
        wrmsr(MSR_IA32_SYSENTER_ESP, current_sstk(), 0);
}
#endif

/*
 * Set MSRs for sysenter/sysexit and syscall/sysret for 64-bit.
 */
static void
fast_syscall_init64(__unused cpu_data_t *cdp)
{
        wrmsr64(MSR_IA32_SYSENTER_CS, SYSENTER_CS); 
        wrmsr64(MSR_IA32_SYSENTER_EIP, UBER64((uintptr_t) hi64_sysenter));
        wrmsr64(MSR_IA32_SYSENTER_ESP, UBER64(current_sstk()));
        /* Enable syscall/sysret */
        wrmsr64(MSR_IA32_EFER, rdmsr64(MSR_IA32_EFER) | MSR_IA32_EFER_SCE);

        /*
         * MSRs for 64-bit syscall/sysret
         * Note USER_CS because sysret uses this + 16 when returning to
         * 64-bit code.
         */
        wrmsr64(MSR_IA32_LSTAR, UBER64((uintptr_t) hi64_syscall));
        wrmsr64(MSR_IA32_STAR, (((uint64_t)USER_CS) << 48) |
                                (((uint64_t)KERNEL64_CS) << 32));
        /*
         * Emulate eflags cleared by sysenter but note that
         * we also clear the trace trap to avoid the complications
         * of single-stepping into a syscall. The nested task bit
         * is also cleared to avoid a spurious "task switch"
         * should we choose to return via an IRET.
         */
        wrmsr64(MSR_IA32_FMASK, EFL_DF|EFL_IF|EFL_TF|EFL_NT);

#ifdef __i386__
        /*
         * Set the Kernel GS base MSR to point to per-cpu data in uber-space.
         * The uber-space handler (hi64_syscall) uses the swapgs instruction.
         */
        wrmsr64(MSR_IA32_KERNEL_GS_BASE, UBER64(cdp));

#if ONLY_SAFE_FOR_LINDA_SERIAL
        kprintf("fast_syscall_init64() KERNEL_GS_BASE=0x%016llx\n",
                        rdmsr64(MSR_IA32_KERNEL_GS_BASE));
#endif
#endif
}


cpu_data_t *
cpu_data_alloc(boolean_t is_boot_cpu)
{
        int             ret;
        cpu_data_t      *cdp;

        if (is_boot_cpu) {
                assert(real_ncpus == 1);
                cdp = cpu_datap(0);
                if (cdp->cpu_processor == NULL) {
                        simple_lock_init(&ncpus_lock, 0);
                        cdp->cpu_processor = cpu_processor_alloc(TRUE);
#if NCOPY_WINDOWS > 0
                        cdp->cpu_pmap = pmap_cpu_alloc(TRUE);
#endif
                }
                return cdp;
        }

        /*
         * Allocate per-cpu data:
         */
        ret = kmem_alloc(kernel_map, (vm_offset_t *) &cdp, sizeof(cpu_data_t));
        if (ret != KERN_SUCCESS) {
                printf("cpu_data_alloc() failed, ret=%d\n", ret);
                goto abort;
        }
        bzero((void*) cdp, sizeof(cpu_data_t));
        cdp->cpu_this = cdp;

        /* Propagate mode */
        cdp->cpu_is64bit = cpu_mode_is64bit();

        /*
         * Allocate interrupt stack:
         */
        ret = kmem_alloc(kernel_map, 
                         (vm_offset_t *) &cdp->cpu_int_stack_top,
                         INTSTACK_SIZE);
        if (ret != KERN_SUCCESS) {
                printf("cpu_data_alloc() int stack failed, ret=%d\n", ret);
                goto abort;
        }
        bzero((void*) cdp->cpu_int_stack_top, INTSTACK_SIZE);
        cdp->cpu_int_stack_top += INTSTACK_SIZE;

        /*
         * Allocate descriptor table:
         * Size depends on cpu mode.
         */

        ret = kmem_alloc(kernel_map, 
                         (vm_offset_t *) &cdp->cpu_desc_tablep,
                         cdp->cpu_is64bit ? sizeof(cpu_desc_table64_t)
                                          : sizeof(cpu_desc_table_t));
        if (ret != KERN_SUCCESS) {
                printf("cpu_data_alloc() desc_table failed, ret=%d\n", ret);
                goto abort;
        }

        /*
         * Allocate LDT
         */
        ret = kmem_alloc(kernel_map, 
                         (vm_offset_t *) &cdp->cpu_ldtp,
                         sizeof(struct real_descriptor) * LDTSZ);
        if (ret != KERN_SUCCESS) {
                printf("cpu_data_alloc() ldt failed, ret=%d\n", ret);
                goto abort;
        }

#if CONFIG_MCA
        /* Machine-check shadow register allocation. */
        mca_cpu_alloc(cdp);
#endif

        simple_lock(&ncpus_lock);

        cpu_data_ptr[real_ncpus] = cdp;
        cdp->cpu_number = real_ncpus;
        real_ncpus++;
        simple_unlock(&ncpus_lock);

        cdp->cpu_nanotime = &pal_rtc_nanotime_info;

        kprintf("cpu_data_alloc(%d) %p desc_table: %p "
                "ldt: %p "
                "int_stack: 0x%lx-0x%lx\n",
                cdp->cpu_number, cdp, cdp->cpu_desc_tablep, cdp->cpu_ldtp,
                (long)(cdp->cpu_int_stack_top - INTSTACK_SIZE), (long)(cdp->cpu_int_stack_top));

        return cdp;

abort:
        if (cdp) {
                if (cdp->cpu_desc_tablep)
                        kfree((void *) cdp->cpu_desc_tablep,
                                sizeof(*cdp->cpu_desc_tablep));
                if (cdp->cpu_int_stack_top)
                        kfree((void *) (cdp->cpu_int_stack_top - INTSTACK_SIZE),
                                INTSTACK_SIZE);
                kfree((void *) cdp, sizeof(*cdp));
        }
        return NULL;
}

boolean_t
valid_user_data_selector(uint16_t selector)
{
    sel_t       sel = selector_to_sel(selector);
    
    if (selector == 0)
        return (TRUE);

    if (sel.ti == SEL_LDT)
        return (TRUE);
    else if (sel.index < GDTSZ) {
        if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
            return (TRUE);
    }
                
    return (FALSE);
}

boolean_t
valid_user_code_selector(uint16_t selector)
{
    sel_t       sel = selector_to_sel(selector);
    
    if (selector == 0)
        return (FALSE);

    if (sel.ti == SEL_LDT) {
        if (sel.rpl == USER_PRIV)
            return (TRUE);
    }
    else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
        if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
            return (TRUE);
    }

    return (FALSE);
}

boolean_t
valid_user_stack_selector(uint16_t selector)
{
    sel_t       sel = selector_to_sel(selector);
    
    if (selector == 0)
        return (FALSE);

    if (sel.ti == SEL_LDT) {
        if (sel.rpl == USER_PRIV)
            return (TRUE);
    }
    else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
        if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
            return (TRUE);
    }
                
    return (FALSE);
}

boolean_t
valid_user_segment_selectors(uint16_t cs,
                uint16_t ss,
                uint16_t ds,
                uint16_t es,
                uint16_t fs,
                uint16_t gs)
{       
        return valid_user_code_selector(cs)  &&
                valid_user_stack_selector(ss) &&
                valid_user_data_selector(ds)  &&
                valid_user_data_selector(es)  &&
                valid_user_data_selector(fs)  &&
                valid_user_data_selector(gs);
}

#if NCOPY_WINDOWS > 0

static vm_offset_t user_window_base = 0;

void
cpu_userwindow_init(int cpu)
{
        cpu_data_t              *cdp = cpu_data_ptr[cpu];
        vm_offset_t             user_window;
        vm_offset_t             vaddr;
        int                     num_cpus;

        num_cpus = ml_get_max_cpus();

        if (cpu >= num_cpus)
                panic("cpu_userwindow_init: cpu > num_cpus");

        if (user_window_base == 0) {

                if (vm_allocate(kernel_map, &vaddr,
                                        (NBPDE * NCOPY_WINDOWS * num_cpus) + NBPDE,
                                        VM_FLAGS_ANYWHERE) != KERN_SUCCESS)
                        panic("cpu_userwindow_init: "
                                        "couldn't allocate user map window");

                /*
                 * window must start on a page table boundary
                 * in the virtual address space
                 */
                user_window_base = (vaddr + (NBPDE - 1)) & ~(NBPDE - 1);

                /*
                 * get rid of any allocation leading up to our
                 * starting boundary
                 */
                vm_deallocate(kernel_map, vaddr, user_window_base - vaddr);

                /*
                 * get rid of tail that we don't need
                 */
                user_window = user_window_base +
                                        (NBPDE * NCOPY_WINDOWS * num_cpus);

                vm_deallocate(kernel_map, user_window,
                                (vaddr +
                                 ((NBPDE * NCOPY_WINDOWS * num_cpus) + NBPDE)) -
                                 user_window);
        }

        user_window = user_window_base + (cpu * NCOPY_WINDOWS * NBPDE);

        cdp->cpu_copywindow_base = user_window;
        /*
         * Abuse this pdp entry, the pdp now actually points to 
         * an array of copy windows addresses.
         */
        cdp->cpu_copywindow_pdp  = pmap_pde(kernel_pmap, user_window);

#ifdef __i386__
        cpu_desc_index_t        *cdi = &cdp->cpu_desc_index;
        cdi->cdi_gdt.ptr[sel_idx(USER_WINDOW_SEL)] = userwindow_desc_pattern;
        cdi->cdi_gdt.ptr[sel_idx(USER_WINDOW_SEL)].offset = user_window;

        fix_desc(&cdi->cdi_gdt.ptr[sel_idx(USER_WINDOW_SEL)], 1);
#endif /* __i386__ */
}

void
cpu_physwindow_init(int cpu)
{
        cpu_data_t              *cdp = cpu_data_ptr[cpu];
        vm_offset_t             phys_window = cdp->cpu_physwindow_base;

        if (phys_window == 0) {
                if (vm_allocate(kernel_map, &phys_window,
                                PAGE_SIZE, VM_FLAGS_ANYWHERE)
                                != KERN_SUCCESS)
                        panic("cpu_physwindow_init: "
                                "couldn't allocate phys map window");

                /*
                 * make sure the page that encompasses the
                 * pte pointer we're interested in actually
                 * exists in the page table
                 */
                pmap_expand(kernel_pmap, phys_window, PMAP_EXPAND_OPTIONS_NONE);

                cdp->cpu_physwindow_base = phys_window;
                cdp->cpu_physwindow_ptep = vtopte(phys_window);
        }
#ifdef __i386__
        cpu_desc_index_t        *cdi = &cdp->cpu_desc_index;
        cdi->cdi_gdt.ptr[sel_idx(PHYS_WINDOW_SEL)] = physwindow_desc_pattern;
        cdi->cdi_gdt.ptr[sel_idx(PHYS_WINDOW_SEL)].offset = phys_window;

        fix_desc(&cdi->cdi_gdt.ptr[sel_idx(PHYS_WINDOW_SEL)], 1);
#endif /* __i386__ */
}
#endif /* NCOPY_WINDOWS > 0 */

/*
 * Load the segment descriptor tables for the current processor.
 */
void
cpu_mode_init(cpu_data_t *cdp)
{
#ifdef __i386__
        if (cdp->cpu_is64bit) {
                cpu_IA32e_enable(cdp);
                cpu_desc_load64(cdp);
                fast_syscall_init64(cdp);
        } else {
                fast_syscall_init(cdp);
        }
#else
        fast_syscall_init64(cdp);
#endif
}

#if __x86_64__
/*
 * Allocate a new interrupt stack for the boot processor from the
 * heap rather than continue to use the statically allocated space.
 * Also switch to a dynamically allocated cpu data area.
 */
void
cpu_data_realloc(void)
{
        int             ret;
        vm_offset_t     stack;
        cpu_data_t      *cdp;
        boolean_t       istate;

        ret = kmem_alloc(kernel_map, &stack, INTSTACK_SIZE);
        if (ret != KERN_SUCCESS) {
                panic("cpu_data_realloc() stack alloc, ret=%d\n", ret);
        }
        bzero((void*) stack, INTSTACK_SIZE);
        stack += INTSTACK_SIZE;

        ret = kmem_alloc(kernel_map, (vm_offset_t *) &cdp, sizeof(cpu_data_t));
        if (ret != KERN_SUCCESS) {
                panic("cpu_data_realloc() cpu data alloc, ret=%d\n", ret);
        }

        /* Copy old contents into new area and make fix-ups */
        bcopy((void *) &cpu_data_master, (void*) cdp, sizeof(cpu_data_t));
        cdp->cpu_this = cdp;
        cdp->cpu_int_stack_top = stack;
        timer_call_initialize_queue(&cdp->rtclock_timer.queue);

        kprintf("Reallocated master cpu data: %p, interrupt stack top: %p\n",
                (void *) cdp, (void *) stack);

        /*
         * With interrupts disabled commmit the new areas.
         */
        istate = ml_set_interrupts_enabled(FALSE);
        cpu_data_ptr[0] = cdp;
        wrmsr64(MSR_IA32_GS_BASE, (uintptr_t) cdp);
        wrmsr64(MSR_IA32_KERNEL_GS_BASE, (uintptr_t) cdp);
        (void) ml_set_interrupts_enabled(istate);
}
#endif /* __x86_64__ */