1 /* Copyright (C) 2012-2023 Free Software Foundation, Inc.
2 Contributed by Richard Henderson <rth@redhat.com>.
3
4 This file is part of the GNU Atomic Library (libatomic).
5
6 Libatomic is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 Libatomic is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13 FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 more details.
15
16 Under Section 7 of GPL version 3, you are granted additional
17 permissions described in the GCC Runtime Library Exception, version
18 3.1, as published by the Free Software Foundation.
19
20 You should have received a copy of the GNU General Public License and
21 a copy of the GCC Runtime Library Exception along with this program;
22 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 <http://www.gnu.org/licenses/>. */
24
25 #include <config/arm/arm-config.h>
26
27
28 /* Kernel helper for 32-bit compare-and-exchange. */
29 typedef int (__kernel_cmpxchg_t) (UWORD oldval, UWORD newval, UWORD *ptr);
30 #define __kernel_cmpxchg (*(__kernel_cmpxchg_t *) 0xffff0fc0)
31
32 /* Kernel helper for 64-bit compare-and-exchange. */
33 typedef int (__kernel_cmpxchg64_t) (const U_8 * oldval, const U_8 * newval,
34 U_8 *ptr);
35 #define __kernel_cmpxchg64 (*(__kernel_cmpxchg64_t *) 0xffff0f60)
36
37 /* Kernel helper for memory barrier. */
38 typedef void (__kernel_dmb_t) (void);
39 #define __kernel_dmb (*(__kernel_dmb_t *) 0xffff0fa0)
40
41 /* Kernel helper page version number. */
42 static inline unsigned*
43 __kernel_helper_version ()
44 {
45 unsigned *volatile addr = (unsigned int *)0xffff0ffc;
46 return addr;
47 }
48
49 #define __kernel_helper_version (*__kernel_helper_version())
50
51 #ifndef HAVE_STREX
52 static inline bool
53 atomic_compare_exchange_w (UWORD *mptr, UWORD *eptr, UWORD newval,
54 bool weak_p UNUSED, int sm UNUSED, int fm UNUSED)
55 {
56 bool ret = true;
57 UWORD oldval;
58
59 oldval = *eptr;
60 if (__builtin_expect (__kernel_cmpxchg (oldval, newval, mptr) != 0, 0))
61 {
62 oldval = *mptr;
63 ret = false;
64 }
65 *eptr = oldval;
66
67 return ret;
68 }
69 # define atomic_compare_exchange_w atomic_compare_exchange_w
70 # if N == WORDSIZE
71 # define atomic_compare_exchange_n atomic_compare_exchange_w
72 # endif
73 #endif /* HAVE_STREX */
74
75 #if !defined(HAVE_STREXBHD) && defined(HAVE_KERNEL64) && N == 8
76 static inline bool
77 atomic_compare_exchange_n (UTYPE *mptr, UTYPE *eptr, UTYPE newval,
78 bool weak_p UNUSED, int sm UNUSED, int fm UNUSED)
79 {
80 if (__kernel_cmpxchg64 (eptr, &newval, mptr) == 0)
81 return true;
82 else
83 {
84 *eptr = *mptr;
85 return false;
86 }
87 }
88 #define atomic_compare_exchange_n atomic_compare_exchange_n
89 #endif
90
91 #if !defined(HAVE_DMB) && !defined(HAVE_DMB_MCR)
92 static inline void
93 pre_barrier(int model UNUSED)
94 {
95 __kernel_dmb ();
96 }
97
98 static inline void
99 post_barrier(int model UNUSED)
100 {
101 __kernel_dmb ();
102 }
103 # define pre_post_barrier 1
104 #endif /* !HAVE_DMB */
105
106 #if HAVE_IFUNC
107 extern bool libat_have_strexbhd HIDDEN;
108
109 # define IFUNC_COND_1 libat_have_strexbhd
110 # define IFUNC_COND_2 (__kernel_helper_version >= 5)
111
112 /* Alternative 1 is -march=armv7-a -- we have everything native. */
113 # if IFUNC_ALT == 1
114 # undef HAVE_ATOMIC_CAS_1
115 # undef HAVE_ATOMIC_CAS_2
116 # undef HAVE_ATOMIC_CAS_4
117 # undef HAVE_ATOMIC_CAS_8
118 # undef HAVE_ATOMIC_EXCHANGE_1
119 # undef HAVE_ATOMIC_EXCHANGE_2
120 # undef HAVE_ATOMIC_EXCHANGE_4
121 # undef HAVE_ATOMIC_EXCHANGE_8
122 # undef HAVE_ATOMIC_LDST_1
123 # undef HAVE_ATOMIC_LDST_2
124 # undef HAVE_ATOMIC_LDST_4
125 # undef HAVE_ATOMIC_LDST_8
126 # undef HAVE_ATOMIC_FETCH_OP_1
127 # undef HAVE_ATOMIC_FETCH_OP_2
128 # undef HAVE_ATOMIC_FETCH_OP_4
129 # undef HAVE_ATOMIC_FETCH_OP_8
130 # undef HAVE_ATOMIC_TAS_1
131 # undef HAVE_ATOMIC_TAS_2
132 # undef HAVE_ATOMIC_TAS_4
133 # undef HAVE_ATOMIC_TAS_8
134 # define HAVE_ATOMIC_CAS_1 1
135 # define HAVE_ATOMIC_CAS_2 1
136 # define HAVE_ATOMIC_CAS_4 1
137 # define HAVE_ATOMIC_CAS_8 1
138 # define HAVE_ATOMIC_EXCHANGE_1 1
139 # define HAVE_ATOMIC_EXCHANGE_2 1
140 # define HAVE_ATOMIC_EXCHANGE_4 1
141 # define HAVE_ATOMIC_EXCHANGE_8 1
142 # define HAVE_ATOMIC_LDST_1 1
143 # define HAVE_ATOMIC_LDST_2 1
144 # define HAVE_ATOMIC_LDST_4 1
145 # define HAVE_ATOMIC_LDST_8 1
146 # define HAVE_ATOMIC_FETCH_OP_1 1
147 # define HAVE_ATOMIC_FETCH_OP_2 1
148 # define HAVE_ATOMIC_FETCH_OP_4 1
149 # define HAVE_ATOMIC_FETCH_OP_8 1
150 # define HAVE_ATOMIC_TAS_1 1
151 # define HAVE_ATOMIC_TAS_2 1
152 # define HAVE_ATOMIC_TAS_4 1
153 # define HAVE_ATOMIC_TAS_8 1
154 # endif /* IFUNC_ALT == 1 */
155
156 # undef MAYBE_HAVE_ATOMIC_CAS_1
157 # define MAYBE_HAVE_ATOMIC_CAS_1 IFUNC_COND_1
158 # undef MAYBE_HAVE_ATOMIC_EXCHANGE_1
159 # define MAYBE_HAVE_ATOMIC_EXCHANGE_1 MAYBE_HAVE_ATOMIC_CAS_1
160 # undef MAYBE_HAVE_ATOMIC_LDST_1
161 # define MAYBE_HAVE_ATOMIC_LDST_1 MAYBE_HAVE_ATOMIC_CAS_1
162 # undef MAYBE_HAVE_ATOMIC_CAS_2
163 # define MAYBE_HAVE_ATOMIC_CAS_2 IFUNC_COND_1
164 # undef MAYBE_HAVE_ATOMIC_EXCHANGE_2
165 # define MAYBE_HAVE_ATOMIC_EXCHANGE_2 MAYBE_HAVE_ATOMIC_CAS_2
166 # undef MAYBE_HAVE_ATOMIC_LDST_2
167 # define MAYBE_HAVE_ATOMIC_LDST_2 MAYBE_HAVE_ATOMIC_CAS_2
168 # undef MAYBE_HAVE_ATOMIC_CAS_4
169 # define MAYBE_HAVE_ATOMIC_CAS_4 IFUNC_COND_1
170 # undef MAYBE_HAVE_ATOMIC_EXCHANGE_4
171 # define MAYBE_HAVE_ATOMIC_EXCHANGE_4 MAYBE_HAVE_ATOMIC_CAS_4
172 # undef MAYBE_HAVE_ATOMIC_LDST_4
173 # define MAYBE_HAVE_ATOMIC_LDST_4 MAYBE_HAVE_ATOMIC_CAS_4
174 # undef MAYBE_HAVE_ATOMIC_CAS_8
175 # define MAYBE_HAVE_ATOMIC_CAS_8 (IFUNC_COND_1 | IFUNC_COND_2)
176 # undef MAYBE_HAVE_ATOMIC_EXCHANGE_8
177 # define MAYBE_HAVE_ATOMIC_EXCHANGE_8 MAYBE_HAVE_ATOMIC_CAS_8
178 # undef MAYBE_HAVE_ATOMIC_LDST_8
179 # define MAYBE_HAVE_ATOMIC_LDST_8 MAYBE_HAVE_ATOMIC_CAS_8
180
181 # define IFUNC_NCOND(N) (N == 8 ? 2 : 1)
182
183 #endif /* HAVE_IFUNC */
184
185 #include_next <host-config.h>