| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | /* |
| 3 | * r2300_switch.S: R2300 specific task switching code. |
| 4 | * |
| 5 | * Copyright (C) 1994, 1995, 1996, 1999 by Ralf Baechle |
| 6 | * Copyright (C) 1994, 1995, 1996 by Andreas Busse |
| 7 | * |
| 8 | * Multi-cpu abstraction and macros for easier reading: |
| 9 | * Copyright (C) 1996 David S. Miller (davem@davemloft.net) |
| 10 | * |
| 11 | * Further modifications to make this work: |
| 12 | * Copyright (c) 1998-2000 Harald Koerfgen |
| 13 | */ |
| 14 | #include <asm/asm.h> |
| 15 | #include <asm/cachectl.h> |
| 16 | #include <asm/export.h> |
| 17 | #include <asm/fpregdef.h> |
| 18 | #include <asm/mipsregs.h> |
| 19 | #include <asm/asm-offsets.h> |
| 20 | #include <asm/regdef.h> |
| 21 | #include <asm/stackframe.h> |
| 22 | #include <asm/thread_info.h> |
| 23 | |
| 24 | #include <asm/asmmacro.h> |
| 25 | |
| 26 | .set mips1 |
| 27 | .align 5 |
| 28 | |
| 29 | /* |
| 30 | * task_struct *resume(task_struct *prev, task_struct *next, |
| 31 | * struct thread_info *next_ti) |
| 32 | */ |
| 33 | LEAF(resume) |
| 34 | mfc0 t1, CP0_STATUS |
| 35 | sw t1, THREAD_STATUS(a0) |
| 36 | cpu_save_nonscratch a0 |
| 37 | sw ra, THREAD_REG31(a0) |
| 38 | |
| 39 | #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP) |
| 40 | PTR_LA t8, __stack_chk_guard |
| 41 | LONG_L t9, TASK_STACK_CANARY(a1) |
| 42 | LONG_S t9, 0(t8) |
| 43 | #endif |
| 44 | |
| 45 | /* |
| 46 | * The order of restoring the registers takes care of the race |
| 47 | * updating $28, $29 and kernelsp without disabling ints. |
| 48 | */ |
| 49 | move $28, a2 |
| 50 | cpu_restore_nonscratch a1 |
| 51 | |
| 52 | addiu t1, $28, _THREAD_SIZE - 32 |
| 53 | sw t1, kernelsp |
| 54 | |
| 55 | mfc0 t1, CP0_STATUS /* Do we really need this? */ |
| 56 | li a3, 0xff01 |
| 57 | and t1, a3 |
| 58 | lw a2, THREAD_STATUS(a1) |
| 59 | nor a3, $0, a3 |
| 60 | and a2, a3 |
| 61 | or a2, t1 |
| 62 | mtc0 a2, CP0_STATUS |
| 63 | move v0, a0 |
| 64 | jr ra |
| 65 | END(resume) |