xref: /openbmc/qemu/target/i386/tcg/mem_helper.c (revision 4011a686)
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 #ifdef CONFIG_USER_ONLY
68     {
69         uint64_t *haddr = g2h(env_cpu(env), a0);
70         cmpv = cpu_to_le64(cmpv);
71         newv = cpu_to_le64(newv);
72         oldv = qatomic_cmpxchg__nocheck(haddr, cmpv, newv);
73         oldv = le64_to_cpu(oldv);
74     }
75 #else
76     {
77         uintptr_t ra = GETPC();
78         int mem_idx = cpu_mmu_index(env, false);
79         TCGMemOpIdx oi = make_memop_idx(MO_TEQ, mem_idx);
80         oldv = helper_atomic_cmpxchgq_le_mmu(env, a0, cmpv, newv, oi, ra);
81     }
82 #endif
83 
84     if (oldv == cmpv) {
85         eflags |= CC_Z;
86     } else {
87         env->regs[R_EAX] = (uint32_t)oldv;
88         env->regs[R_EDX] = (uint32_t)(oldv >> 32);
89         eflags &= ~CC_Z;
90     }
91     CC_SRC = eflags;
92 #else
93     cpu_loop_exit_atomic(env_cpu(env), GETPC());
94 #endif /* CONFIG_ATOMIC64 */
95 }
96 
97 #ifdef TARGET_X86_64
98 void helper_cmpxchg16b_unlocked(CPUX86State *env, target_ulong a0)
99 {
100     uintptr_t ra = GETPC();
101     Int128 oldv, cmpv, newv;
102     uint64_t o0, o1;
103     int eflags;
104     bool success;
105 
106     if ((a0 & 0xf) != 0) {
107         raise_exception_ra(env, EXCP0D_GPF, GETPC());
108     }
109     eflags = cpu_cc_compute_all(env, CC_OP);
110 
111     cmpv = int128_make128(env->regs[R_EAX], env->regs[R_EDX]);
112     newv = int128_make128(env->regs[R_EBX], env->regs[R_ECX]);
113 
114     o0 = cpu_ldq_data_ra(env, a0 + 0, ra);
115     o1 = cpu_ldq_data_ra(env, a0 + 8, ra);
116 
117     oldv = int128_make128(o0, o1);
118     success = int128_eq(oldv, cmpv);
119     if (!success) {
120         newv = oldv;
121     }
122 
123     cpu_stq_data_ra(env, a0 + 0, int128_getlo(newv), ra);
124     cpu_stq_data_ra(env, a0 + 8, int128_gethi(newv), ra);
125 
126     if (success) {
127         eflags |= CC_Z;
128     } else {
129         env->regs[R_EAX] = int128_getlo(oldv);
130         env->regs[R_EDX] = int128_gethi(oldv);
131         eflags &= ~CC_Z;
132     }
133     CC_SRC = eflags;
134 }
135 
136 void helper_cmpxchg16b(CPUX86State *env, target_ulong a0)
137 {
138     uintptr_t ra = GETPC();
139 
140     if ((a0 & 0xf) != 0) {
141         raise_exception_ra(env, EXCP0D_GPF, ra);
142     } else if (HAVE_CMPXCHG128) {
143         int eflags = cpu_cc_compute_all(env, CC_OP);
144 
145         Int128 cmpv = int128_make128(env->regs[R_EAX], env->regs[R_EDX]);
146         Int128 newv = int128_make128(env->regs[R_EBX], env->regs[R_ECX]);
147 
148         int mem_idx = cpu_mmu_index(env, false);
149         TCGMemOpIdx oi = make_memop_idx(MO_TEQ | MO_ALIGN_16, mem_idx);
150         Int128 oldv = helper_atomic_cmpxchgo_le_mmu(env, a0, cmpv,
151                                                     newv, oi, ra);
152 
153         if (int128_eq(oldv, cmpv)) {
154             eflags |= CC_Z;
155         } else {
156             env->regs[R_EAX] = int128_getlo(oldv);
157             env->regs[R_EDX] = int128_gethi(oldv);
158             eflags &= ~CC_Z;
159         }
160         CC_SRC = eflags;
161     } else {
162         cpu_loop_exit_atomic(env_cpu(env), ra);
163     }
164 }
165 #endif
166 
167 void helper_boundw(CPUX86State *env, target_ulong a0, int v)
168 {
169     int low, high;
170 
171     low = cpu_ldsw_data_ra(env, a0, GETPC());
172     high = cpu_ldsw_data_ra(env, a0 + 2, GETPC());
173     v = (int16_t)v;
174     if (v < low || v > high) {
175         if (env->hflags & HF_MPX_EN_MASK) {
176             env->bndcs_regs.sts = 0;
177         }
178         raise_exception_ra(env, EXCP05_BOUND, GETPC());
179     }
180 }
181 
182 void helper_boundl(CPUX86State *env, target_ulong a0, int v)
183 {
184     int low, high;
185 
186     low = cpu_ldl_data_ra(env, a0, GETPC());
187     high = cpu_ldl_data_ra(env, a0 + 4, GETPC());
188     if (v < low || v > high) {
189         if (env->hflags & HF_MPX_EN_MASK) {
190             env->bndcs_regs.sts = 0;
191         }
192         raise_exception_ra(env, EXCP05_BOUND, GETPC());
193     }
194 }
195