xref: /openbmc/qemu/linux-user/mips/target_prctl.h (revision bad5cfcd)
1 /*
2  * MIPS specific prctl functions for linux-user
3  *
4  * SPDX-License-Identifier: GPL-2.0-or-later
5  */
6 #ifndef MIPS_TARGET_PRCTL_H
7 #define MIPS_TARGET_PRCTL_H
8 
9 static abi_long do_prctl_get_fp_mode(CPUArchState *env)
10 {
11     abi_long ret = 0;
12 
13     if (env->CP0_Status & (1 << CP0St_FR)) {
14         ret |= PR_FP_MODE_FR;
15     }
16     if (env->CP0_Config5 & (1 << CP0C5_FRE)) {
17         ret |= PR_FP_MODE_FRE;
18     }
19     return ret;
20 }
21 #define do_prctl_get_fp_mode do_prctl_get_fp_mode
22 
23 static abi_long do_prctl_set_fp_mode(CPUArchState *env, abi_long arg2)
24 {
25     bool old_fr = env->CP0_Status & (1 << CP0St_FR);
26     bool old_fre = env->CP0_Config5 & (1 << CP0C5_FRE);
27     bool new_fr = arg2 & PR_FP_MODE_FR;
28     bool new_fre = arg2 & PR_FP_MODE_FRE;
29     const unsigned int known_bits = PR_FP_MODE_FR | PR_FP_MODE_FRE;
30 
31     /* If nothing to change, return right away, successfully.  */
32     if (old_fr == new_fr && old_fre == new_fre) {
33         return 0;
34     }
35     /* Check the value is valid */
36     if (arg2 & ~known_bits) {
37         return -TARGET_EOPNOTSUPP;
38     }
39     /* Setting FRE without FR is not supported.  */
40     if (new_fre && !new_fr) {
41         return -TARGET_EOPNOTSUPP;
42     }
43     if (new_fr && !(env->active_fpu.fcr0 & (1 << FCR0_F64))) {
44         /* FR1 is not supported */
45         return -TARGET_EOPNOTSUPP;
46     }
47     if (!new_fr && (env->active_fpu.fcr0 & (1 << FCR0_F64))
48         && !(env->CP0_Status_rw_bitmask & (1 << CP0St_FR))) {
49         /* cannot set FR=0 */
50         return -TARGET_EOPNOTSUPP;
51     }
52     if (new_fre && !(env->active_fpu.fcr0 & (1 << FCR0_FREP))) {
53         /* Cannot set FRE=1 */
54         return -TARGET_EOPNOTSUPP;
55     }
56 
57     int i;
58     fpr_t *fpr = env->active_fpu.fpr;
59     for (i = 0; i < 32 ; i += 2) {
60         if (!old_fr && new_fr) {
61             fpr[i].w[!FP_ENDIAN_IDX] = fpr[i + 1].w[FP_ENDIAN_IDX];
62         } else if (old_fr && !new_fr) {
63             fpr[i + 1].w[FP_ENDIAN_IDX] = fpr[i].w[!FP_ENDIAN_IDX];
64         }
65     }
66 
67     if (new_fr) {
68         env->CP0_Status |= (1 << CP0St_FR);
69         env->hflags |= MIPS_HFLAG_F64;
70     } else {
71         env->CP0_Status &= ~(1 << CP0St_FR);
72         env->hflags &= ~MIPS_HFLAG_F64;
73     }
74     if (new_fre) {
75         env->CP0_Config5 |= (1 << CP0C5_FRE);
76         if (env->active_fpu.fcr0 & (1 << FCR0_FREP)) {
77             env->hflags |= MIPS_HFLAG_FRE;
78         }
79     } else {
80         env->CP0_Config5 &= ~(1 << CP0C5_FRE);
81         env->hflags &= ~MIPS_HFLAG_FRE;
82     }
83 
84     return 0;
85 }
86 #define do_prctl_set_fp_mode do_prctl_set_fp_mode
87 
88 #endif /* MIPS_TARGET_PRCTL_H */
89