LXR linux/arch/mips/kernel/scall64-n32.S

   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * Copyright (C) 1995, 96, 97, 98, 99, 2000, 01 by Ralf Baechle
   7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   8 * Copyright (C) 2001 MIPS Technologies, Inc.
   9 */
  10#include <linux/errno.h>
  11#include <asm/asm.h>
  12#include <asm/asmmacro.h>
  13#include <asm/irqflags.h>
  14#include <asm/mipsregs.h>
  15#include <asm/regdef.h>
  16#include <asm/stackframe.h>
  17#include <asm/thread_info.h>
  18#include <asm/unistd.h>
  19
  20#ifndef CONFIG_MIPS32_O32
  21/* No O32, so define handle_sys here */
  22#define handle_sysn32 handle_sys
  23#endif
  24
  25        .align  5
  26NESTED(handle_sysn32, PT_SIZE, sp)
  27#ifndef CONFIG_MIPS32_O32
  28        .set    noat
  29        SAVE_SOME
  30        TRACE_IRQS_ON_RELOAD
  31        STI
  32        .set    at
  33#endif
  34
  35        dsubu   t0, v0, __NR_N32_Linux  # check syscall number
  36        sltiu   t0, t0, __NR_N32_Linux_syscalls
  37
  38#ifndef CONFIG_MIPS32_O32
  39        ld      t1, PT_EPC(sp)          # skip syscall on return
  40        daddiu  t1, 4                   # skip to next instruction
  41        sd      t1, PT_EPC(sp)
  42#endif
  43        beqz    t0, not_n32_scall
  44
  45        sd      a3, PT_R26(sp)          # save a3 for syscall restarting
  46
  47        li      t1, _TIF_WORK_SYSCALL_ENTRY
  48        LONG_L  t0, TI_FLAGS($28)       # syscall tracing enabled?
  49        and     t0, t1, t0
  50        bnez    t0, n32_syscall_trace_entry
  51
  52syscall_common:
  53        dsll    t0, v0, 3               # offset into table
  54        ld      t2, (sysn32_call_table - (__NR_N32_Linux * 8))(t0)
  55
  56        jalr    t2                      # Do The Real Thing (TM)
  57
  58        li      t0, -EMAXERRNO - 1      # error?
  59        sltu    t0, t0, v0
  60        sd      t0, PT_R7(sp)           # set error flag
  61        beqz    t0, 1f
  62
  63        ld      t1, PT_R2(sp)           # syscall number
  64        dnegu   v0                      # error
  65        sd      t1, PT_R0(sp)           # save it for syscall restarting
  661:      sd      v0, PT_R2(sp)           # result
  67
  68        j       syscall_exit_partial
  69
  70/* ------------------------------------------------------------------------ */
  71
  72n32_syscall_trace_entry:
  73        SAVE_STATIC
  74        move    a0, sp
  75        move    a1, v0
  76        jal     syscall_trace_enter
  77
  78        bltz    v0, 1f                  # seccomp failed? Skip syscall
  79
  80        RESTORE_STATIC
  81        ld      v0, PT_R2(sp)           # Restore syscall (maybe modified)
  82        ld      a0, PT_R4(sp)           # Restore argument registers
  83        ld      a1, PT_R5(sp)
  84        ld      a2, PT_R6(sp)
  85        ld      a3, PT_R7(sp)
  86        ld      a4, PT_R8(sp)
  87        ld      a5, PT_R9(sp)
  88
  89        dsubu   t2, v0, __NR_N32_Linux  # check (new) syscall number
  90        sltiu   t0, t2, __NR_N32_Linux_syscalls
  91        beqz    t0, not_n32_scall
  92
  93        j       syscall_common
  94
  951:      j       syscall_exit
  96
  97not_n32_scall:
  98        /* This is not an n32 compatibility syscall, pass it on to
  99           the n64 syscall handlers.  */
 100        j       handle_sys64
 101
 102        END(handle_sysn32)
 103
 104#define __SYSCALL(nr, entry)    PTR entry
 105        .type   sysn32_call_table, @object
 106EXPORT(sysn32_call_table)
 107#include <asm/syscall_table_64_n32.h>
 108#undef __SYSCALL
 109