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ef2f826c HC |
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) 2014 Lemote Corporation. | |
7 | * written by Huacai Chen <chenhc@lemote.com> | |
8 | * | |
9 | * based on arch/mips/cavium-octeon/cpu.c | |
10 | * Copyright (C) 2009 Wind River Systems, | |
11 | * written by Ralf Baechle <ralf@linux-mips.org> | |
12 | */ | |
13 | #include <linux/init.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/notifier.h> | |
16 | ||
17 | #include <asm/fpu.h> | |
18 | #include <asm/cop2.h> | |
19 | #include <asm/current.h> | |
20 | #include <asm/mipsregs.h> | |
21 | ||
22 | static int loongson_cu2_call(struct notifier_block *nfb, unsigned long action, | |
23 | void *data) | |
24 | { | |
bfcdf130 | 25 | int fpu_owned; |
ef2f826c HC |
26 | int fr = !test_thread_flag(TIF_32BIT_FPREGS); |
27 | ||
28 | switch (action) { | |
29 | case CU2_EXCEPTION: | |
30 | preempt_disable(); | |
bfcdf130 | 31 | fpu_owned = __is_fpu_owner(); |
ef2f826c HC |
32 | if (!fr) |
33 | set_c0_status(ST0_CU1 | ST0_CU2); | |
34 | else | |
35 | set_c0_status(ST0_CU1 | ST0_CU2 | ST0_FR); | |
36 | enable_fpu_hazard(); | |
37 | KSTK_STATUS(current) |= (ST0_CU1 | ST0_CU2); | |
38 | if (fr) | |
39 | KSTK_STATUS(current) |= ST0_FR; | |
40 | else | |
41 | KSTK_STATUS(current) &= ~ST0_FR; | |
bfcdf130 HC |
42 | /* If FPU is owned, we needn't init or restore fp */ |
43 | if (!fpu_owned) { | |
ef2f826c HC |
44 | set_thread_flag(TIF_USEDFPU); |
45 | if (!used_math()) { | |
9b26616c | 46 | _init_fpu(current->thread.fpu.fcr31); |
ef2f826c HC |
47 | set_used_math(); |
48 | } else | |
49 | _restore_fp(current); | |
50 | } | |
51 | preempt_enable(); | |
52 | ||
53 | return NOTIFY_STOP; /* Don't call default notifier */ | |
54 | } | |
55 | ||
56 | return NOTIFY_OK; /* Let default notifier send signals */ | |
57 | } | |
58 | ||
59 | static int __init loongson_cu2_setup(void) | |
60 | { | |
61 | return cu2_notifier(loongson_cu2_call, 0); | |
62 | } | |
63 | early_initcall(loongson_cu2_setup); |