xref: /openbmc/qemu/target/riscv/internals.h (revision 4005a799)
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 bool mmuidx_sum(int mmu_idx)
41 {
42     return (mmu_idx & 3) == MMUIdx_S_SUM;
43 }
44 
45 /* share data between vector helpers and decode code */
46 FIELD(VDATA, VM, 0, 1)
47 FIELD(VDATA, LMUL, 1, 3)
48 FIELD(VDATA, VTA, 4, 1)
49 FIELD(VDATA, VTA_ALL_1S, 5, 1)
50 FIELD(VDATA, VMA, 6, 1)
51 FIELD(VDATA, NF, 7, 4)
52 FIELD(VDATA, WD, 7, 1)
53 
54 /* float point classify helpers */
55 target_ulong fclass_h(uint64_t frs1);
56 target_ulong fclass_s(uint64_t frs1);
57 target_ulong fclass_d(uint64_t frs1);
58 
59 #ifndef CONFIG_USER_ONLY
60 extern const VMStateDescription vmstate_riscv_cpu;
61 #endif
62 
63 enum {
64     RISCV_FRM_RNE = 0,  /* Round to Nearest, ties to Even */
65     RISCV_FRM_RTZ = 1,  /* Round towards Zero */
66     RISCV_FRM_RDN = 2,  /* Round Down */
67     RISCV_FRM_RUP = 3,  /* Round Up */
68     RISCV_FRM_RMM = 4,  /* Round to Nearest, ties to Max Magnitude */
69     RISCV_FRM_DYN = 7,  /* Dynamic rounding mode */
70     RISCV_FRM_ROD = 8,  /* Round to Odd */
71 };
72 
73 static inline uint64_t nanbox_s(CPURISCVState *env, float32 f)
74 {
75     /* the value is sign-extended instead of NaN-boxing for zfinx */
76     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
77         return (int32_t)f;
78     } else {
79         return f | MAKE_64BIT_MASK(32, 32);
80     }
81 }
82 
83 static inline float32 check_nanbox_s(CPURISCVState *env, uint64_t f)
84 {
85     /* Disable NaN-boxing check when enable zfinx */
86     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
87         return (uint32_t)f;
88     }
89 
90     uint64_t mask = MAKE_64BIT_MASK(32, 32);
91 
92     if (likely((f & mask) == mask)) {
93         return (uint32_t)f;
94     } else {
95         return 0x7fc00000u; /* default qnan */
96     }
97 }
98 
99 static inline uint64_t nanbox_h(CPURISCVState *env, float16 f)
100 {
101     /* the value is sign-extended instead of NaN-boxing for zfinx */
102     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
103         return (int16_t)f;
104     } else {
105         return f | MAKE_64BIT_MASK(16, 48);
106     }
107 }
108 
109 static inline float16 check_nanbox_h(CPURISCVState *env, uint64_t f)
110 {
111     /* Disable nanbox check when enable zfinx */
112     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
113         return (uint16_t)f;
114     }
115 
116     uint64_t mask = MAKE_64BIT_MASK(16, 48);
117 
118     if (likely((f & mask) == mask)) {
119         return (uint16_t)f;
120     } else {
121         return 0x7E00u; /* default qnan */
122     }
123 }
124 
125 #endif
126