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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001/* SPDX-License-Identifier: GPL-2.0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/*
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:
Justin P. Mattock79add622011-04-04 14:15:29 -07009 * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 *
11 * Further modifications to make this work:
12 * Copyright (c) 1998-2000 Harald Koerfgen
13 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <asm/asm.h>
15#include <asm/cachectl.h>
Paul Burton29830c12016-11-07 11:14:10 +000016#include <asm/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <asm/fpregdef.h>
18#include <asm/mipsregs.h>
Sam Ravnborg048eb582005-09-09 22:32:31 +020019#include <asm/asm-offsets.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#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/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070030 * task_struct *resume(task_struct *prev, task_struct *next,
Paul Burton085c2f22015-09-21 10:07:42 -070031 * struct thread_info *next_ti)
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 */
33LEAF(resume)
Atsushi Nemoto53231802007-04-14 02:37:26 +090034 mfc0 t1, CP0_STATUS
35 sw t1, THREAD_STATUS(a0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 cpu_save_nonscratch a0
37 sw ra, THREAD_REG31(a0)
38
Linus Torvalds050e9ba2018-06-14 12:21:18 +090039#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
James Hogan8b3c5692013-10-07 12:14:26 +010040 PTR_LA t8, __stack_chk_guard
Gregory Fong1400eb62013-06-17 19:36:07 +000041 LONG_L t9, TASK_STACK_CANARY(a1)
42 LONG_S t9, 0(t8)
43#endif
44
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 /*
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)