xref: /openbmc/qemu/target/riscv/internals.h (revision c8f8a995)
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  *  - HLV/HLVX/HSV adds 0b100
31  */
32 #define MMUIdx_U            0
33 #define MMUIdx_S            1
34 #define MMUIdx_S_SUM        2
35 #define MMUIdx_M            3
36 #define MMU_HYP_ACCESS_BIT  (1 << 2)
37 
38 /* share data between vector helpers and decode code */
39 FIELD(VDATA, VM, 0, 1)
40 FIELD(VDATA, LMUL, 1, 3)
41 FIELD(VDATA, VTA, 4, 1)
42 FIELD(VDATA, VTA_ALL_1S, 5, 1)
43 FIELD(VDATA, VMA, 6, 1)
44 FIELD(VDATA, NF, 7, 4)
45 FIELD(VDATA, WD, 7, 1)
46 
47 /* float point classify helpers */
48 target_ulong fclass_h(uint64_t frs1);
49 target_ulong fclass_s(uint64_t frs1);
50 target_ulong fclass_d(uint64_t frs1);
51 
52 #ifndef CONFIG_USER_ONLY
53 extern const VMStateDescription vmstate_riscv_cpu;
54 #endif
55 
56 enum {
57     RISCV_FRM_RNE = 0,  /* Round to Nearest, ties to Even */
58     RISCV_FRM_RTZ = 1,  /* Round towards Zero */
59     RISCV_FRM_RDN = 2,  /* Round Down */
60     RISCV_FRM_RUP = 3,  /* Round Up */
61     RISCV_FRM_RMM = 4,  /* Round to Nearest, ties to Max Magnitude */
62     RISCV_FRM_DYN = 7,  /* Dynamic rounding mode */
63     RISCV_FRM_ROD = 8,  /* Round to Odd */
64 };
65 
66 static inline uint64_t nanbox_s(CPURISCVState *env, float32 f)
67 {
68     /* the value is sign-extended instead of NaN-boxing for zfinx */
69     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
70         return (int32_t)f;
71     } else {
72         return f | MAKE_64BIT_MASK(32, 32);
73     }
74 }
75 
76 static inline float32 check_nanbox_s(CPURISCVState *env, uint64_t f)
77 {
78     /* Disable NaN-boxing check when enable zfinx */
79     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
80         return (uint32_t)f;
81     }
82 
83     uint64_t mask = MAKE_64BIT_MASK(32, 32);
84 
85     if (likely((f & mask) == mask)) {
86         return (uint32_t)f;
87     } else {
88         return 0x7fc00000u; /* default qnan */
89     }
90 }
91 
92 static inline uint64_t nanbox_h(CPURISCVState *env, float16 f)
93 {
94     /* the value is sign-extended instead of NaN-boxing for zfinx */
95     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
96         return (int16_t)f;
97     } else {
98         return f | MAKE_64BIT_MASK(16, 48);
99     }
100 }
101 
102 static inline float16 check_nanbox_h(CPURISCVState *env, uint64_t f)
103 {
104     /* Disable nanbox check when enable zfinx */
105     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
106         return (uint16_t)f;
107     }
108 
109     uint64_t mask = MAKE_64BIT_MASK(16, 48);
110 
111     if (likely((f & mask) == mask)) {
112         return (uint16_t)f;
113     } else {
114         return 0x7E00u; /* default qnan */
115     }
116 }
117 
118 #endif
119