root/arch/mips/kernel/scall64-n32.S
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1995, 96, 97, 98, 99, 2000, 01 by Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Copyright (C) 2001 MIPS Technologies, Inc.
 */
#include <linux/errno.h>
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/irqflags.h>
#include <asm/mipsregs.h>
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/thread_info.h>
#include <asm/unistd.h>

#ifndef CONFIG_MIPS32_O32
/* No O32, so define handle_sys here */
#define handle_sysn32 handle_sys
#endif

        .align  5
NESTED(handle_sysn32, PT_SIZE, sp)
#ifndef CONFIG_MIPS32_O32
        .set    noat
        SAVE_SOME
        TRACE_IRQS_ON_RELOAD
        STI
        .set    at
#endif

        dsubu   t0, v0, __NR_N32_Linux  # check syscall number
        sltiu   t0, t0, __NR_N32_Linux_syscalls

#ifndef CONFIG_MIPS32_O32
        ld      t1, PT_EPC(sp)          # skip syscall on return
        daddiu  t1, 4                   # skip to next instruction
        sd      t1, PT_EPC(sp)
#endif
        beqz    t0, not_n32_scall

        sd      a3, PT_R26(sp)          # save a3 for syscall restarting

        LONG_S  v0, TI_SYSCALL($28)     # Store syscall number

        li      t1, _TIF_WORK_SYSCALL_ENTRY
        LONG_L  t0, TI_FLAGS($28)       # syscall tracing enabled?
        and     t0, t1, t0
        bnez    t0, n32_syscall_trace_entry

syscall_common:
        dsll    t0, v0, 3               # offset into table
        ld      t2, (sysn32_call_table - (__NR_N32_Linux * 8))(t0)

        jalr    t2                      # Do The Real Thing (TM)

        li      t0, -EMAXERRNO - 1      # error?
        sltu    t0, t0, v0
        sd      t0, PT_R7(sp)           # set error flag
        beqz    t0, 1f

        ld      t1, PT_R2(sp)           # syscall number
        dnegu   v0                      # error
        sd      t1, PT_R0(sp)           # save it for syscall restarting
1:      sd      v0, PT_R2(sp)           # result

        j       syscall_exit_partial

/* ------------------------------------------------------------------------ */

n32_syscall_trace_entry:
        SAVE_STATIC
        move    a0, sp
        jal     syscall_trace_enter

        bltz    v0, 1f                  # seccomp failed? Skip syscall

        RESTORE_STATIC
        ld      v0, PT_R2(sp)           # Restore syscall (maybe modified)
        ld      a0, PT_R4(sp)           # Restore argument registers
        ld      a1, PT_R5(sp)
        ld      a2, PT_R6(sp)
        ld      a3, PT_R7(sp)
        ld      a4, PT_R8(sp)
        ld      a5, PT_R9(sp)

        dsubu   t2, v0, __NR_N32_Linux  # check (new) syscall number
        sltiu   t0, t2, __NR_N32_Linux_syscalls
        beqz    t0, not_n32_scall

        j       syscall_common

1:      j       syscall_exit

not_n32_scall:
        /* This is not an n32 compatibility syscall, pass it on to
           the n64 syscall handlers.  */
        j       handle_sys64

        END(handle_sysn32)

#define __SYSCALL(nr, entry)    PTR_WD entry
        .type   sysn32_call_table, @object
EXPORT(sysn32_call_table)
#include <asm/syscall_table_n32.h>