xref: /openbmc/qemu/target/i386/tcg/mem_helper.c (revision 30b6852c)
1 /*
2  *  x86 memory access helpers
3  *
4  *  Copyright (c) 2003 Fabrice Bellard
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "cpu.h"
22 #include "exec/helper-proto.h"
23 #include "exec/exec-all.h"
24 #include "exec/cpu_ldst.h"
25 #include "qemu/int128.h"
26 #include "qemu/atomic128.h"
27 #include "tcg/tcg.h"
28 #include "helper-tcg.h"
29 
30 void helper_cmpxchg8b_unlocked(CPUX86State *env, target_ulong a0)
31 {
32     uintptr_t ra = GETPC();
33     uint64_t oldv, cmpv, newv;
34     int eflags;
35 
36     eflags = cpu_cc_compute_all(env, CC_OP);
37 
38     cmpv = deposit64(env->regs[R_EAX], 32, 32, env->regs[R_EDX]);
39     newv = deposit64(env->regs[R_EBX], 32, 32, env->regs[R_ECX]);
40 
41     oldv = cpu_ldq_data_ra(env, a0, ra);
42     newv = (cmpv == oldv ? newv : oldv);
43     /* always do the store */
44     cpu_stq_data_ra(env, a0, newv, ra);
45 
46     if (oldv == cmpv) {
47         eflags |= CC_Z;
48     } else {
49         env->regs[R_EAX] = (uint32_t)oldv;
50         env->regs[R_EDX] = (uint32_t)(oldv >> 32);
51         eflags &= ~CC_Z;
52     }
53     CC_SRC = eflags;
54 }
55 
56 void helper_cmpxchg8b(CPUX86State *env, target_ulong a0)
57 {
58 #ifdef CONFIG_ATOMIC64
59     uint64_t oldv, cmpv, newv;
60     int eflags;
61 
62     eflags = cpu_cc_compute_all(env, CC_OP);
63 
64     cmpv = deposit64(env->regs[R_EAX], 32, 32, env->regs[R_EDX]);
65     newv = deposit64(env->regs[R_EBX], 32, 32, env->regs[R_ECX]);
66 
67     {
68         uintptr_t ra = GETPC();
69         int mem_idx = cpu_mmu_index(env, false);
70         MemOpIdx oi = make_memop_idx(MO_TEQ, mem_idx);
71         oldv = cpu_atomic_cmpxchgq_le_mmu(env, a0, cmpv, newv, oi, ra);
72     }
73 
74     if (oldv == cmpv) {
75         eflags |= CC_Z;
76     } else {
77         env->regs[R_EAX] = (uint32_t)oldv;
78         env->regs[R_EDX] = (uint32_t)(oldv >> 32);
79         eflags &= ~CC_Z;
80     }
81     CC_SRC = eflags;
82 #else
83     cpu_loop_exit_atomic(env_cpu(env), GETPC());
84 #endif /* CONFIG_ATOMIC64 */
85 }
86 
87 #ifdef TARGET_X86_64
88 void helper_cmpxchg16b_unlocked(CPUX86State *env, target_ulong a0)
89 {
90     uintptr_t ra = GETPC();
91     Int128 oldv, cmpv, newv;
92     uint64_t o0, o1;
93     int eflags;
94     bool success;
95 
96     if ((a0 & 0xf) != 0) {
97         raise_exception_ra(env, EXCP0D_GPF, GETPC());
98     }
99     eflags = cpu_cc_compute_all(env, CC_OP);
100 
101     cmpv = int128_make128(env->regs[R_EAX], env->regs[R_EDX]);
102     newv = int128_make128(env->regs[R_EBX], env->regs[R_ECX]);
103 
104     o0 = cpu_ldq_data_ra(env, a0 + 0, ra);
105     o1 = cpu_ldq_data_ra(env, a0 + 8, ra);
106 
107     oldv = int128_make128(o0, o1);
108     success = int128_eq(oldv, cmpv);
109     if (!success) {
110         newv = oldv;
111     }
112 
113     cpu_stq_data_ra(env, a0 + 0, int128_getlo(newv), ra);
114     cpu_stq_data_ra(env, a0 + 8, int128_gethi(newv), ra);
115 
116     if (success) {
117         eflags |= CC_Z;
118     } else {
119         env->regs[R_EAX] = int128_getlo(oldv);
120         env->regs[R_EDX] = int128_gethi(oldv);
121         eflags &= ~CC_Z;
122     }
123     CC_SRC = eflags;
124 }
125 
126 void helper_cmpxchg16b(CPUX86State *env, target_ulong a0)
127 {
128     uintptr_t ra = GETPC();
129 
130     if ((a0 & 0xf) != 0) {
131         raise_exception_ra(env, EXCP0D_GPF, ra);
132     } else if (HAVE_CMPXCHG128) {
133         int eflags = cpu_cc_compute_all(env, CC_OP);
134 
135         Int128 cmpv = int128_make128(env->regs[R_EAX], env->regs[R_EDX]);
136         Int128 newv = int128_make128(env->regs[R_EBX], env->regs[R_ECX]);
137 
138         int mem_idx = cpu_mmu_index(env, false);
139         MemOpIdx oi = make_memop_idx(MO_TEQ | MO_ALIGN_16, mem_idx);
140         Int128 oldv = cpu_atomic_cmpxchgo_le_mmu(env, a0, cmpv, newv, oi, ra);
141 
142         if (int128_eq(oldv, cmpv)) {
143             eflags |= CC_Z;
144         } else {
145             env->regs[R_EAX] = int128_getlo(oldv);
146             env->regs[R_EDX] = int128_gethi(oldv);
147             eflags &= ~CC_Z;
148         }
149         CC_SRC = eflags;
150     } else {
151         cpu_loop_exit_atomic(env_cpu(env), ra);
152     }
153 }
154 #endif
155 
156 void helper_boundw(CPUX86State *env, target_ulong a0, int v)
157 {
158     int low, high;
159 
160     low = cpu_ldsw_data_ra(env, a0, GETPC());
161     high = cpu_ldsw_data_ra(env, a0 + 2, GETPC());
162     v = (int16_t)v;
163     if (v < low || v > high) {
164         if (env->hflags & HF_MPX_EN_MASK) {
165             env->bndcs_regs.sts = 0;
166         }
167         raise_exception_ra(env, EXCP05_BOUND, GETPC());
168     }
169 }
170 
171 void helper_boundl(CPUX86State *env, target_ulong a0, int v)
172 {
173     int low, high;
174 
175     low = cpu_ldl_data_ra(env, a0, GETPC());
176     high = cpu_ldl_data_ra(env, a0 + 4, GETPC());
177     if (v < low || v > high) {
178         if (env->hflags & HF_MPX_EN_MASK) {
179             env->bndcs_regs.sts = 0;
180         }
181         raise_exception_ra(env, EXCP05_BOUND, GETPC());
182     }
183 }
184