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 /*

 *  Commpage syscalls

 *

 *  Copyright (c) 2006 Pierre d'Herbemont

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, see <http://www.gnu.org/licenses/>.

 */

#include <fcntl.h>

#include <stdio.h>

#include <stdlib.h>

#include <errno.h>

#include <mach/message.h>

#include <mach/mach.h>

#include <mach/mach_time.h>

#include <sys/time.h>

#include <sys/mman.h>

#include <libkern/OSAtomic.h>

#include "qemu.h"

//#define DEBUG_COMMPAGE

#ifdef DEBUG_COMMPAGE

# define DPRINTF(...) do { qemu_log(__VA_ARGS__); printf(__VA_ARGS__); } while(0)

#else

# define DPRINTF(...) do { qemu_log(__VA_ARGS__); } while(0)

#endif

/********************************************************************

 *   Commpage definitions

 */

#ifdef TARGET_I386

/* Reserve space for the commpage see xnu/osfmk/i386/cpu_capabilities.h */

# define COMMPAGE_START (-16 * 4096) /* base address is -20 * 4096 */

# define COMMPAGE_SIZE  (0x1240) /* _COMM_PAGE_AREA_LENGTH is 19 * 4096 */

#elif defined(TARGET_PPC)

/* Reserve space for the commpage see xnu/osfmk/ppc/cpu_capabilities.h */

# define COMMPAGE_START (-8*4096)

# define COMMPAGE_SIZE  (2*4096) /* its _COMM_PAGE_AREA_USED but _COMM_PAGE_AREA_LENGTH is 7*4096 */

#endif

void do_compare_and_swap32(void *cpu_env, int num);

void do_compare_and_swap64(void *cpu_env, int num);

void do_add_atomic_word32(void *cpu_env, int num);

void do_cgettimeofday(void *cpu_env, int num, uint32_t arg1);

void do_nanotime(void *cpu_env, int num);

void unimpl_commpage(void *cpu_env, int num);

typedef void (*commpage_8args_function_t)(uint32_t arg1, uint32_t arg2, uint32_t arg3,

                uint32_t arg4, uint32_t arg5, uint32_t arg6, uint32_t arg7,

                uint32_t arg8);

typedef void (*commpage_indirect_function_t)(void *cpu_env, int num, uint32_t arg1,

                uint32_t arg2, uint32_t arg3,  uint32_t arg4, uint32_t arg5,

                uint32_t arg6, uint32_t arg7, uint32_t arg8);

#define HAS_PTR  0x10

#define NO_PTR   0x20

#define CALL_DIRECT   0x1

#define CALL_INDIRECT 0x2

#define COMMPAGE_ENTRY(name, nargs, offset, func, options) \

    { #name, offset, nargs, options, (commpage_8args_function_t)func }

struct commpage_entry {

    char * name;

    int offset;

    int nargs;

    char options;

    commpage_8args_function_t function;

};

static inline int commpage_code_num(struct commpage_entry *entry)

{

    if((entry->options & HAS_PTR))

        return entry->offset + 4;

    else

        return entry->offset;

}

static inline int commpage_is_indirect(struct commpage_entry *entry)

{

    return !(entry->options & CALL_DIRECT);

}

/********************************************************************

 *   Commpage entry

 */

static struct commpage_entry commpage_entries[] =

{

    COMMPAGE_ENTRY(compare_and_swap32,    0, 0x080,  do_compare_and_swap32, CALL_INDIRECT | HAS_PTR),

    COMMPAGE_ENTRY(compare_and_swap64,    0, 0x0c0,  do_compare_and_swap64, CALL_INDIRECT | HAS_PTR),

    COMMPAGE_ENTRY(enqueue,               0, 0x100,  unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(dequeue,               0, 0x140,  unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(memory_barrier,        0, 0x180,  unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(add_atomic_word32,     0, 0x1a0,  do_add_atomic_word32,  CALL_INDIRECT | HAS_PTR),

    COMMPAGE_ENTRY(add_atomic_word64,     0, 0x1c0,  unimpl_commpage,       CALL_INDIRECT | HAS_PTR),

    COMMPAGE_ENTRY(mach_absolute_time,    0, 0x200,  unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(spinlock_try,          1, 0x220,  unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(spinlock_lock,         1, 0x260,  OSSpinLockLock,        CALL_DIRECT),

    COMMPAGE_ENTRY(spinlock_unlock,       1, 0x2a0,  OSSpinLockUnlock,      CALL_DIRECT),

    COMMPAGE_ENTRY(pthread_getspecific,   0, 0x2c0,  unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(gettimeofday,          1, 0x2e0,  do_cgettimeofday,      CALL_INDIRECT),

    COMMPAGE_ENTRY(sys_dcache_flush,      0, 0x4e0,  unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(sys_icache_invalidate, 0, 0x520,  unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(pthread_self,          0, 0x580,  unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(relinquish,            0, 0x5c0,  unimpl_commpage,       CALL_INDIRECT),

#ifdef TARGET_I386

    COMMPAGE_ENTRY(bts,                   0, 0x5e0,  unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(btc,                   0, 0x5f0,  unimpl_commpage,       CALL_INDIRECT),

#endif

    COMMPAGE_ENTRY(bzero,                 2, 0x600,  bzero,                 CALL_DIRECT),

    COMMPAGE_ENTRY(bcopy,                 3, 0x780,  bcopy,                 CALL_DIRECT),

    COMMPAGE_ENTRY(memcpy,                3, 0x7a0,  memcpy,                CALL_DIRECT),

#ifdef TARGET_I386

    COMMPAGE_ENTRY(old_nanotime,          0, 0xf80,  do_nanotime,           CALL_INDIRECT),

    COMMPAGE_ENTRY(memset_pattern,        0, 0xf80,  unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(long_copy,             0, 0x1200, unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(sysintegrity,          0, 0x1600, unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(nanotime,              0, 0x1700, do_nanotime,           CALL_INDIRECT),

#elif TARGET_PPC

    COMMPAGE_ENTRY(compare_and_swap32b,   0, 0xf80,  unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(compare_and_swap64b,   0, 0xfc0,  unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(memset_pattern,        0, 0x1000, unimpl_commpage,       CALL_INDIRECT),

    COMMPAGE_ENTRY(bigcopy,               0, 0x1140, unimpl_commpage,       CALL_INDIRECT),

#endif

};

/********************************************************************

 *   Commpage backdoor

 */

static inline void print_commpage_entry(struct commpage_entry entry)

{

    printf("@0x%x %s\n", entry.offset, entry.name);

}

static inline void install_commpage_backdoor_for_entry(struct commpage_entry entry)

{

#ifdef TARGET_I386

    char * commpage = (char*)(COMMPAGE_START+entry.offset);

    int c = 0;

    if(entry.options & HAS_PTR)

    {

        commpage[c++] = (COMMPAGE_START+entry.offset+4) & 0xff;

        commpage[c++] = ((COMMPAGE_START+entry.offset+4) >> 8) & 0xff;

        commpage[c++] = ((COMMPAGE_START+entry.offset+4) >> 16) & 0xff;

        commpage[c++] = ((COMMPAGE_START+entry.offset+4) >> 24) & 0xff;

    }

    commpage[c++] = 0xcd;

    commpage[c++] = 0x79; /* int 0x79 */

    commpage[c++] = 0xc3; /* ret */

#else

    qerror("can't install the commpage on this arch\n");

#endif

}

/********************************************************************

 *   Commpage initialization

 */

void commpage_init(void)

{

#if (defined(__i386__) ^ defined(TARGET_I386)) || (defined(_ARCH_PPC) ^ defined(TARGET_PPC))

    int i;

    void * commpage = (void *)target_mmap( COMMPAGE_START, COMMPAGE_SIZE,

                           PROT_WRITE | PROT_READ, MAP_ANONYMOUS | MAP_FIXED, -1, 0);

    if((int)commpage != COMMPAGE_START)

        qerror("can't allocate the commpage\n");

    bzero(commpage, COMMPAGE_SIZE);

    /* XXX: commpage data not handled */

    for(i = 0; i < ARRAY_SIZE(commpage_entries); i++)

        install_commpage_backdoor_for_entry(commpage_entries[i]);

#else

    /* simply map our pages so they can be executed

       XXX: we don't really want to do that since in the ppc on ppc situation we may

       not able to run commpages host optimized instructions (like G5's on a G5),

       hence this is sometimes a broken fix. */

    page_set_flags(COMMPAGE_START, COMMPAGE_START+COMMPAGE_SIZE, PROT_EXEC | PROT_READ | PAGE_VALID);

#endif

}

/********************************************************************

 *   Commpage implementation

 */

void do_compare_and_swap32(void *cpu_env, int num)

{

#ifdef TARGET_I386

    uint32_t old = ((CPUX86State*)cpu_env)->regs[R_EAX];

    uint32_t *value = (uint32_t*)((CPUX86State*)cpu_env)->regs[R_ECX];

    DPRINTF("commpage: compare_and_swap32(%x,new,%p)\n", old, value);

    if(value && old == tswap32(*value))

    {

        uint32_t new = ((CPUX86State*)cpu_env)->regs[R_EDX];

        *value = tswap32(new);

        /* set zf flag */

        ((CPUX86State*)cpu_env)->eflags |= 0x40;

    }

    else

    {

        ((CPUX86State*)cpu_env)->regs[R_EAX] = tswap32(*value);

        /* unset zf flag */

        ((CPUX86State*)cpu_env)->eflags &= ~0x40;

    }

#else

    qerror("do_compare_and_swap32 unimplemented");

#endif

}

void do_compare_and_swap64(void *cpu_env, int num)

{

#ifdef TARGET_I386

    /* OSAtomicCompareAndSwap64 is not available on non 64 bits ppc, here is a raw implementation */

    uint64_t old, new, swapped_val;

    uint64_t *value = (uint64_t*)((CPUX86State*)cpu_env)->regs[R_ESI];

    old = (uint64_t)((uint64_t)((CPUX86State*)cpu_env)->regs[R_EDX]) << 32 | (uint64_t)((CPUX86State*)cpu_env)->regs[R_EAX];

    DPRINTF("commpage: compare_and_swap64(%" PRIx64 ",new,%p)\n", old, value);

    swapped_val = tswap64(*value);

    if(old == swapped_val)

    {

        new = (uint64_t)((uint64_t)((CPUX86State*)cpu_env)->regs[R_ECX]) << 32 | (uint64_t)((CPUX86State*)cpu_env)->regs[R_EBX];

        *value = tswap64(new);

        /* set zf flag */

        ((CPUX86State*)cpu_env)->eflags |= 0x40;

    }

    else

    {

        ((CPUX86State*)cpu_env)->regs[R_EAX] = (uint32_t)(swapped_val);

        ((CPUX86State*)cpu_env)->regs[R_EDX] = (uint32_t)(swapped_val >> 32);

        /* unset zf flag */

        ((CPUX86State*)cpu_env)->eflags &= ~0x40;

    }

#else

    qerror("do_compare_and_swap64 unimplemented");

#endif

}

void do_add_atomic_word32(void *cpu_env, int num)

{

#ifdef TARGET_I386

    uint32_t amt = ((CPUX86State*)cpu_env)->regs[R_EAX];

    uint32_t *value = (uint32_t*)((CPUX86State*)cpu_env)->regs[R_EDX];

    uint32_t swapped_value = tswap32(*value);

    DPRINTF("commpage: add_atomic_word32(%x,%p)\n", amt, value);

    /* old value in EAX */

    ((CPUX86State*)cpu_env)->regs[R_EAX] = swapped_value;

    *value = tswap32(swapped_value + amt);

#else

    qerror("do_add_atomic_word32 unimplemented");

#endif

}

void do_cgettimeofday(void *cpu_env, int num, uint32_t arg1)

{

#ifdef TARGET_I386

    extern int __commpage_gettimeofday(struct timeval *);

    DPRINTF("commpage: gettimeofday(0x%x)\n", arg1);

    struct timeval *time = (struct timeval *)arg1;

    int ret = __commpage_gettimeofday(time);

    tswap32s((uint32_t*)&time->tv_sec);

    tswap32s((uint32_t*)&time->tv_usec);

    ((CPUX86State*)cpu_env)->regs[R_EAX] = ret; /* Success */

#else

    qerror("do_gettimeofday unimplemented");

#endif

}

void do_nanotime(void *cpu_env, int num)

{

#ifdef TARGET_I386

    uint64_t t = mach_absolute_time();

    ((CPUX86State*)cpu_env)->regs[R_EAX] = (int)(t & 0xffffffff);

    ((CPUX86State*)cpu_env)->regs[R_EDX] = (int)((t >> 32) & 0xffffffff);

#else

    qerror("do_nanotime unimplemented");

#endif

}

void unimpl_commpage(void *cpu_env, int num)

{

    qerror("qemu: commpage function 0x%x not implemented\n", num);

}

/********************************************************************

 *   do_commpage - called by the main cpu loop

 */

void

do_commpage(void *cpu_env, int num, uint32_t arg1, uint32_t arg2, uint32_t arg3,

                uint32_t arg4, uint32_t arg5, uint32_t arg6, uint32_t arg7,

                uint32_t arg8)

{

    int i, found = 0;

    arg1 = tswap32(arg1);

    arg2 = tswap32(arg2);

    arg3 = tswap32(arg3);

    arg4 = tswap32(arg4);

    arg5 = tswap32(arg5);

    arg6 = tswap32(arg6);

    arg7 = tswap32(arg7);

    arg8 = tswap32(arg8);

    num = num-COMMPAGE_START-2;

    for(i = 0; i < ARRAY_SIZE(commpage_entries); i++) {

        if( num == commpage_code_num(&commpage_entries[i]) )

        {

            DPRINTF("commpage: %s %s\n", commpage_entries[i].name, commpage_is_indirect(&commpage_entries[i]) ? "[indirect]" : "[direct]");

            found = 1;

            if(commpage_is_indirect(&commpage_entries[i]))

            {

                commpage_indirect_function_t function = (commpage_indirect_function_t)commpage_entries[i].function;

                function(cpu_env, num, arg1, arg2, arg3,

                    arg4, arg5, arg6, arg7, arg8);

            }

            else

            {

                commpage_entries[i].function(arg1, arg2, arg3,

                    arg4, arg5, arg6, arg7, arg8);

            }

            break;

        }

    }

    if(!found)

    {

        gemu_log("qemu: commpage function 0x%x not defined\n", num);

        gdb_handlesig (cpu_env, SIGTRAP);

        exit(-1);

    }

}