xref: /openbmc/qemu/target/loongarch/tcg/csr_helper.c (revision 0d70c5aa1bbfb0f5099d53d6e084337a8246cc0c)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * LoongArch emulation helpers for CSRs
4  *
5  * Copyright (c) 2021 Loongson Technology Corporation Limited
6  */
7 
8 #include "qemu/osdep.h"
9 #include "qemu/log.h"
10 #include "qemu/main-loop.h"
11 #include "cpu.h"
12 #include "internals.h"
13 #include "qemu/host-utils.h"
14 #include "exec/helper-proto.h"
15 #include "exec/cputlb.h"
16 #include "accel/tcg/cpu-ldst.h"
17 #include "hw/irq.h"
18 #include "cpu-csr.h"
19 
20 target_ulong helper_csrwr_stlbps(CPULoongArchState *env, target_ulong val)
21 {
22     int64_t old_v = env->CSR_STLBPS;
23 
24     /*
25      * The real hardware only supports the min tlb_ps is 12
26      * tlb_ps=0 may cause undefined-behavior.
27      */
28     uint8_t tlb_ps = FIELD_EX64(env->CSR_STLBPS, CSR_STLBPS, PS);
29     if (!check_ps(env, tlb_ps)) {
30         qemu_log_mask(LOG_GUEST_ERROR,
31                       "Attempted set ps %d\n", tlb_ps);
32     } else {
33         /* Only update PS field, reserved bit keeps zero */
34         env->CSR_STLBPS = FIELD_DP64(old_v, CSR_STLBPS, PS, tlb_ps);
35     }
36 
37     return old_v;
38 }
39 
40 target_ulong helper_csrrd_pgd(CPULoongArchState *env)
41 {
42     int64_t v;
43 
44     if (env->CSR_TLBRERA & 0x1) {
45         v = env->CSR_TLBRBADV;
46     } else {
47         v = env->CSR_BADV;
48     }
49 
50     if ((v >> 63) & 0x1) {
51         v = env->CSR_PGDH;
52     } else {
53         v = env->CSR_PGDL;
54     }
55 
56     return v;
57 }
58 
59 target_ulong helper_csrrd_cpuid(CPULoongArchState *env)
60 {
61     LoongArchCPU *lac = env_archcpu(env);
62 
63     env->CSR_CPUID = CPU(lac)->cpu_index;
64 
65     return env->CSR_CPUID;
66 }
67 
68 target_ulong helper_csrrd_tval(CPULoongArchState *env)
69 {
70     LoongArchCPU *cpu = env_archcpu(env);
71 
72     return cpu_loongarch_get_constant_timer_ticks(cpu);
73 }
74 
75 target_ulong helper_csrwr_estat(CPULoongArchState *env, target_ulong val)
76 {
77     int64_t old_v = env->CSR_ESTAT;
78 
79     /* Only IS[1:0] can be written */
80     env->CSR_ESTAT = deposit64(env->CSR_ESTAT, 0, 2, val);
81 
82     return old_v;
83 }
84 
85 target_ulong helper_csrwr_asid(CPULoongArchState *env, target_ulong val)
86 {
87     int64_t old_v = env->CSR_ASID;
88 
89     /* Only ASID filed of CSR_ASID can be written */
90     env->CSR_ASID = deposit64(env->CSR_ASID, 0, 10, val);
91     if (old_v != env->CSR_ASID) {
92         tlb_flush(env_cpu(env));
93     }
94     return old_v;
95 }
96 
97 target_ulong helper_csrwr_tcfg(CPULoongArchState *env, target_ulong val)
98 {
99     LoongArchCPU *cpu = env_archcpu(env);
100     int64_t old_v = env->CSR_TCFG;
101 
102     cpu_loongarch_store_constant_timer_config(cpu, val);
103 
104     return old_v;
105 }
106 
107 target_ulong helper_csrwr_ticlr(CPULoongArchState *env, target_ulong val)
108 {
109     LoongArchCPU *cpu = env_archcpu(env);
110     int64_t old_v = 0;
111 
112     if (val & 0x1) {
113         bql_lock();
114         loongarch_cpu_set_irq(cpu, IRQ_TIMER, 0);
115         bql_unlock();
116     }
117     return old_v;
118 }
119 
120 target_ulong helper_csrwr_pwcl(CPULoongArchState *env, target_ulong val)
121 {
122     uint8_t shift, ptbase;
123     int64_t old_v = env->CSR_PWCL;
124 
125     /*
126      * The real hardware only supports 64bit PTE width now, 128bit or others
127      * treated as illegal.
128      */
129     shift = FIELD_EX64(val, CSR_PWCL, PTEWIDTH);
130     ptbase = FIELD_EX64(val, CSR_PWCL, PTBASE);
131     if (shift) {
132         qemu_log_mask(LOG_GUEST_ERROR,
133                       "Attempted set pte width with %d bit\n", 64 << shift);
134         val = FIELD_DP64(val, CSR_PWCL, PTEWIDTH, 0);
135     }
136     if (!check_ps(env, ptbase)) {
137          qemu_log_mask(LOG_GUEST_ERROR,
138                       "Attempted set ptbase 2^%d\n", ptbase);
139     }
140     env->CSR_PWCL = val;
141     return old_v;
142 }
143