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Diffstat (limited to 'arch/mips/kernel/r4k_switch.S')
| -rw-r--r-- | arch/mips/kernel/r4k_switch.S | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S new file mode 100644 index 0000000000..58232ae6cf --- /dev/null +++ b/arch/mips/kernel/r4k_switch.S @@ -0,0 +1,59 @@ +/* + * 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) 1994, 1995, 1996, 1998, 1999, 2002, 2003 Ralf Baechle + * Copyright (C) 1996 David S. Miller (davem@davemloft.net) + * Copyright (C) 1994, 1995, 1996, by Andreas Busse + * Copyright (C) 1999 Silicon Graphics, Inc. + * Copyright (C) 2000 MIPS Technologies, Inc. + * written by Carsten Langgaard, carstenl@mips.com + */ +#include <asm/asm.h> +#include <asm/cachectl.h> +#include <asm/mipsregs.h> +#include <asm/asm-offsets.h> +#include <asm/regdef.h> +#include <asm/stackframe.h> +#include <asm/thread_info.h> + +#include <asm/asmmacro.h> + +/* + * task_struct *resume(task_struct *prev, task_struct *next, + * struct thread_info *next_ti) + */ + .align 5 + LEAF(resume) + mfc0 t1, CP0_STATUS + LONG_S t1, THREAD_STATUS(a0) + cpu_save_nonscratch a0 + LONG_S ra, THREAD_REG31(a0) + +#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP) + PTR_LA t8, __stack_chk_guard + LONG_L t9, TASK_STACK_CANARY(a1) + LONG_S t9, 0(t8) +#endif + + /* + * The order of restoring the registers takes care of the race + * updating $28, $29 and kernelsp without disabling ints. + */ + move $28, a2 + cpu_restore_nonscratch a1 + + PTR_ADDU t0, $28, _THREAD_SIZE - 32 + set_saved_sp t0, t1, t2 + mfc0 t1, CP0_STATUS /* Do we really need this? */ + li a3, 0xff01 + and t1, a3 + LONG_L a2, THREAD_STATUS(a1) + nor a3, $0, a3 + and a2, a3 + or a2, t1 + mtc0 a2, CP0_STATUS + move v0, a0 + jr ra + END(resume) |