LXR linux/arch/mips/kernel/r4k

   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) 1994, 1995, 1996, 1998, 1999, 2002, 2003 Ralf Baechle
   7 * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
   8 * Copyright (C) 1994, 1995, 1996, by Andreas Busse
   9 * Copyright (C) 1999 Silicon Graphics, Inc.
  10 * Copyright (C) 2000 MIPS Technologies, Inc.
  11 *    written by Carsten Langgaard, carstenl@mips.com
  12 */
  13#include <asm/asm.h>
  14#include <asm/cachectl.h>
  15#include <asm/mipsregs.h>
  16#include <asm/asm-offsets.h>
  17#include <asm/regdef.h>
  18#include <asm/stackframe.h>
  19#include <asm/thread_info.h>
  20
  21#include <asm/asmmacro.h>
  22
  23/*
  24 * task_struct *resume(task_struct *prev, task_struct *next,
  25 *                     struct thread_info *next_ti)
  26 */
  27        .align  5
  28        LEAF(resume)
  29        mfc0    t1, CP0_STATUS
  30        LONG_S  t1, THREAD_STATUS(a0)
  31        cpu_save_nonscratch a0
  32        LONG_S  ra, THREAD_REG31(a0)
  33
  34#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
  35        PTR_LA  t8, __stack_chk_guard
  36        LONG_L  t9, TASK_STACK_CANARY(a1)
  37        LONG_S  t9, 0(t8)
  38#endif
  39
  40        /*
  41         * The order of restoring the registers takes care of the race
  42         * updating $28, $29 and kernelsp without disabling ints.
  43         */
  44        move    $28, a2
  45        cpu_restore_nonscratch a1
  46
  47        PTR_ADDU        t0, $28, _THREAD_SIZE - 32
  48        set_saved_sp    t0, t1, t2
  49        mfc0    t1, CP0_STATUS          /* Do we really need this? */
  50        li      a3, 0xff01
  51        and     t1, a3
  52        LONG_L  a2, THREAD_STATUS(a1)
  53        nor     a3, $0, a3
  54        and     a2, a3
  55        or      a2, t1
  56        mtc0    a2, CP0_STATUS
  57        move    v0, a0
  58        jr      ra
  59        END(resume)
  60