aboutsummaryrefslogtreecommitdiff
path: root/target/loongarch/cpu_helper.c
blob: b0658773b0b8bb1aa09ba9845b4a922daf6a3573 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * LoongArch CPU helpers for qemu
 *
 * Copyright (c) 2024 Loongson Technology Corporation Limited
 *
 */

#include "qemu/osdep.h"
#include "cpu.h"
#include "internals.h"
#include "cpu-csr.h"

static int loongarch_map_tlb_entry(CPULoongArchState *env, hwaddr *physical,
                                   int *prot, target_ulong address,
                                   int access_type, int index, int mmu_idx)
{
    LoongArchTLB *tlb = &env->tlb[index];
    uint64_t plv = mmu_idx;
    uint64_t tlb_entry, tlb_ppn;
    uint8_t tlb_ps, n, tlb_v, tlb_d, tlb_plv, tlb_nx, tlb_nr, tlb_rplv;

    if (index >= LOONGARCH_STLB) {
        tlb_ps = FIELD_EX64(tlb->tlb_misc, TLB_MISC, PS);
    } else {
        tlb_ps = FIELD_EX64(env->CSR_STLBPS, CSR_STLBPS, PS);
    }
    n = (address >> tlb_ps) & 0x1;/* Odd or even */

    tlb_entry = n ? tlb->tlb_entry1 : tlb->tlb_entry0;
    tlb_v = FIELD_EX64(tlb_entry, TLBENTRY, V);
    tlb_d = FIELD_EX64(tlb_entry, TLBENTRY, D);
    tlb_plv = FIELD_EX64(tlb_entry, TLBENTRY, PLV);
    if (is_la64(env)) {
        tlb_ppn = FIELD_EX64(tlb_entry, TLBENTRY_64, PPN);
        tlb_nx = FIELD_EX64(tlb_entry, TLBENTRY_64, NX);
        tlb_nr = FIELD_EX64(tlb_entry, TLBENTRY_64, NR);
        tlb_rplv = FIELD_EX64(tlb_entry, TLBENTRY_64, RPLV);
    } else {
        tlb_ppn = FIELD_EX64(tlb_entry, TLBENTRY_32, PPN);
        tlb_nx = 0;
        tlb_nr = 0;
        tlb_rplv = 0;
    }

    /* Remove sw bit between bit12 -- bit PS*/
    tlb_ppn = tlb_ppn & ~(((0x1UL << (tlb_ps - 12)) -1));

    /* Check access rights */
    if (!tlb_v) {
        return TLBRET_INVALID;
    }

    if (access_type == MMU_INST_FETCH && tlb_nx) {
        return TLBRET_XI;
    }

    if (access_type == MMU_DATA_LOAD && tlb_nr) {
        return TLBRET_RI;
    }

    if (((tlb_rplv == 0) && (plv > tlb_plv)) ||
        ((tlb_rplv == 1) && (plv != tlb_plv))) {
        return TLBRET_PE;
    }

    if ((access_type == MMU_DATA_STORE) && !tlb_d) {
        return TLBRET_DIRTY;
    }

    *physical = (tlb_ppn << R_TLBENTRY_64_PPN_SHIFT) |
                (address & MAKE_64BIT_MASK(0, tlb_ps));
    *prot = PAGE_READ;
    if (tlb_d) {
        *prot |= PAGE_WRITE;
    }
    if (!tlb_nx) {
        *prot |= PAGE_EXEC;
    }
    return TLBRET_MATCH;
}

/*
 * One tlb entry holds an adjacent odd/even pair, the vpn is the
 * content of the virtual page number divided by 2. So the
 * compare vpn is bit[47:15] for 16KiB page. while the vppn
 * field in tlb entry contains bit[47:13], so need adjust.
 * virt_vpn = vaddr[47:13]
 */
bool loongarch_tlb_search(CPULoongArchState *env, target_ulong vaddr,
                          int *index)
{
    LoongArchTLB *tlb;
    uint16_t csr_asid, tlb_asid, stlb_idx;
    uint8_t tlb_e, tlb_ps, tlb_g, stlb_ps;
    int i, compare_shift;
    uint64_t vpn, tlb_vppn;

    csr_asid = FIELD_EX64(env->CSR_ASID, CSR_ASID, ASID);
    stlb_ps = FIELD_EX64(env->CSR_STLBPS, CSR_STLBPS, PS);
    vpn = (vaddr & TARGET_VIRT_MASK) >> (stlb_ps + 1);
    stlb_idx = vpn & 0xff; /* VA[25:15] <==> TLBIDX.index for 16KiB Page */
    compare_shift = stlb_ps + 1 - R_TLB_MISC_VPPN_SHIFT;

    /* Search STLB */
    for (i = 0; i < 8; ++i) {
        tlb = &env->tlb[i * 256 + stlb_idx];
        tlb_e = FIELD_EX64(tlb->tlb_misc, TLB_MISC, E);
        if (tlb_e) {
            tlb_vppn = FIELD_EX64(tlb->tlb_misc, TLB_MISC, VPPN);
            tlb_asid = FIELD_EX64(tlb->tlb_misc, TLB_MISC, ASID);
            tlb_g = FIELD_EX64(tlb->tlb_entry0, TLBENTRY, G);

            if ((tlb_g == 1 || tlb_asid == csr_asid) &&
                (vpn == (tlb_vppn >> compare_shift))) {
                *index = i * 256 + stlb_idx;
                return true;
            }
        }
    }

    /* Search MTLB */
    for (i = LOONGARCH_STLB; i < LOONGARCH_TLB_MAX; ++i) {
        tlb = &env->tlb[i];
        tlb_e = FIELD_EX64(tlb->tlb_misc, TLB_MISC, E);
        if (tlb_e) {
            tlb_vppn = FIELD_EX64(tlb->tlb_misc, TLB_MISC, VPPN);
            tlb_ps = FIELD_EX64(tlb->tlb_misc, TLB_MISC, PS);
            tlb_asid = FIELD_EX64(tlb->tlb_misc, TLB_MISC, ASID);
            tlb_g = FIELD_EX64(tlb->tlb_entry0, TLBENTRY, G);
            compare_shift = tlb_ps + 1 - R_TLB_MISC_VPPN_SHIFT;
            vpn = (vaddr & TARGET_VIRT_MASK) >> (tlb_ps + 1);
            if ((tlb_g == 1 || tlb_asid == csr_asid) &&
                (vpn == (tlb_vppn >> compare_shift))) {
                *index = i;
                return true;
            }
        }
    }
    return false;
}

static int loongarch_map_address(CPULoongArchState *env, hwaddr *physical,
                                 int *prot, target_ulong address,
                                 MMUAccessType access_type, int mmu_idx)
{
    int index, match;

    match = loongarch_tlb_search(env, address, &index);
    if (match) {
        return loongarch_map_tlb_entry(env, physical, prot,
                                       address, access_type, index, mmu_idx);
    }

    return TLBRET_NOMATCH;
}

static hwaddr dmw_va2pa(CPULoongArchState *env, target_ulong va,
                        target_ulong dmw)
{
    if (is_la64(env)) {
        return va & TARGET_VIRT_MASK;
    } else {
        uint32_t pseg = FIELD_EX32(dmw, CSR_DMW_32, PSEG);
        return (va & MAKE_64BIT_MASK(0, R_CSR_DMW_32_VSEG_SHIFT)) | \
            (pseg << R_CSR_DMW_32_VSEG_SHIFT);
    }
}

int get_physical_address(CPULoongArchState *env, hwaddr *physical,
                         int *prot, target_ulong address,
                         MMUAccessType access_type, int mmu_idx)
{
    int user_mode = mmu_idx == MMU_USER_IDX;
    int kernel_mode = mmu_idx == MMU_KERNEL_IDX;
    uint32_t plv, base_c, base_v;
    int64_t addr_high;
    uint8_t da = FIELD_EX64(env->CSR_CRMD, CSR_CRMD, DA);
    uint8_t pg = FIELD_EX64(env->CSR_CRMD, CSR_CRMD, PG);

    /* Check PG and DA */
    if (da & !pg) {
        *physical = address & TARGET_PHYS_MASK;
        *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
        return TLBRET_MATCH;
    }

    plv = kernel_mode | (user_mode << R_CSR_DMW_PLV3_SHIFT);
    if (is_la64(env)) {
        base_v = address >> R_CSR_DMW_64_VSEG_SHIFT;
    } else {
        base_v = address >> R_CSR_DMW_32_VSEG_SHIFT;
    }
    /* Check direct map window */
    for (int i = 0; i < 4; i++) {
        if (is_la64(env)) {
            base_c = FIELD_EX64(env->CSR_DMW[i], CSR_DMW_64, VSEG);
        } else {
            base_c = FIELD_EX64(env->CSR_DMW[i], CSR_DMW_32, VSEG);
        }
        if ((plv & env->CSR_DMW[i]) && (base_c == base_v)) {
            *physical = dmw_va2pa(env, address, env->CSR_DMW[i]);
            *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
            return TLBRET_MATCH;
        }
    }

    /* Check valid extension */
    addr_high = sextract64(address, TARGET_VIRT_ADDR_SPACE_BITS, 16);
    if (!(addr_high == 0 || addr_high == -1)) {
        return TLBRET_BADADDR;
    }

    /* Mapped address */
    return loongarch_map_address(env, physical, prot, address,
                                 access_type, mmu_idx);
}

hwaddr loongarch_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
{
    LoongArchCPU *cpu = LOONGARCH_CPU(cs);
    CPULoongArchState *env = &cpu->env;
    hwaddr phys_addr;
    int prot;

    if (get_physical_address(env, &phys_addr, &prot, addr, MMU_DATA_LOAD,
                             cpu_mmu_index(env, false)) != 0) {
        return -1;
    }
    return phys_addr;
}