xref: /openbmc/qemu/target/riscv/internals.h (revision 02369f79)
1 /*
2  * QEMU RISC-V CPU -- internal functions and types
3  *
4  * Copyright (c) 2020 T-Head Semiconductor Co., Ltd. All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2 or later, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License along with
16  * this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #ifndef RISCV_CPU_INTERNALS_H
20 #define RISCV_CPU_INTERNALS_H
21 
22 #include "hw/registerfields.h"
23 
24 /*
25  * The current MMU Modes are:
26  *  - U                 0b000
27  *  - S                 0b001
28  *  - S+SUM             0b010
29  *  - M                 0b011
30  *  - U+2STAGE          0b100
31  *  - S+2STAGE          0b101
32  *  - S+SUM+2STAGE      0b110
33  */
34 #define MMUIdx_U            0
35 #define MMUIdx_S            1
36 #define MMUIdx_S_SUM        2
37 #define MMUIdx_M            3
38 #define MMU_2STAGE_BIT      (1 << 2)
39 
40 static inline int mmuidx_priv(int mmu_idx)
41 {
42     int ret = mmu_idx & 3;
43     if (ret == MMUIdx_S_SUM) {
44         ret = PRV_S;
45     }
46     return ret;
47 }
48 
49 static inline bool mmuidx_sum(int mmu_idx)
50 {
51     return (mmu_idx & 3) == MMUIdx_S_SUM;
52 }
53 
54 static inline bool mmuidx_2stage(int mmu_idx)
55 {
56     return mmu_idx & MMU_2STAGE_BIT;
57 }
58 
59 /* share data between vector helpers and decode code */
60 FIELD(VDATA, VM, 0, 1)
61 FIELD(VDATA, LMUL, 1, 3)
62 FIELD(VDATA, VTA, 4, 1)
63 FIELD(VDATA, VTA_ALL_1S, 5, 1)
64 FIELD(VDATA, VMA, 6, 1)
65 FIELD(VDATA, NF, 7, 4)
66 FIELD(VDATA, WD, 7, 1)
67 
68 /* float point classify helpers */
69 target_ulong fclass_h(uint64_t frs1);
70 target_ulong fclass_s(uint64_t frs1);
71 target_ulong fclass_d(uint64_t frs1);
72 
73 #ifndef CONFIG_USER_ONLY
74 extern const VMStateDescription vmstate_riscv_cpu;
75 #endif
76 
77 enum {
78     RISCV_FRM_RNE = 0,  /* Round to Nearest, ties to Even */
79     RISCV_FRM_RTZ = 1,  /* Round towards Zero */
80     RISCV_FRM_RDN = 2,  /* Round Down */
81     RISCV_FRM_RUP = 3,  /* Round Up */
82     RISCV_FRM_RMM = 4,  /* Round to Nearest, ties to Max Magnitude */
83     RISCV_FRM_DYN = 7,  /* Dynamic rounding mode */
84     RISCV_FRM_ROD = 8,  /* Round to Odd */
85 };
86 
87 static inline uint64_t nanbox_s(CPURISCVState *env, float32 f)
88 {
89     /* the value is sign-extended instead of NaN-boxing for zfinx */
90     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
91         return (int32_t)f;
92     } else {
93         return f | MAKE_64BIT_MASK(32, 32);
94     }
95 }
96 
97 static inline float32 check_nanbox_s(CPURISCVState *env, uint64_t f)
98 {
99     /* Disable NaN-boxing check when enable zfinx */
100     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
101         return (uint32_t)f;
102     }
103 
104     uint64_t mask = MAKE_64BIT_MASK(32, 32);
105 
106     if (likely((f & mask) == mask)) {
107         return (uint32_t)f;
108     } else {
109         return 0x7fc00000u; /* default qnan */
110     }
111 }
112 
113 static inline uint64_t nanbox_h(CPURISCVState *env, float16 f)
114 {
115     /* the value is sign-extended instead of NaN-boxing for zfinx */
116     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
117         return (int16_t)f;
118     } else {
119         return f | MAKE_64BIT_MASK(16, 48);
120     }
121 }
122 
123 static inline float16 check_nanbox_h(CPURISCVState *env, uint64_t f)
124 {
125     /* Disable nanbox check when enable zfinx */
126     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
127         return (uint16_t)f;
128     }
129 
130     uint64_t mask = MAKE_64BIT_MASK(16, 48);
131 
132     if (likely((f & mask) == mask)) {
133         return (uint16_t)f;
134     } else {
135         return 0x7E00u; /* default qnan */
136     }
137 }
138 
139 #endif
140