1 /* Copyright (C) 2012-2019 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 #define __kernel_helper_version (*(unsigned int *)0xffff0ffc)
43
44
45 #ifndef HAVE_STREX
46 static inline bool
atomic_compare_exchange_w(UWORD * mptr,UWORD * eptr,UWORD newval,bool weak_p UNUSED,int sm UNUSED,int fm UNUSED)47 atomic_compare_exchange_w (UWORD *mptr, UWORD *eptr, UWORD newval,
48 bool weak_p UNUSED, int sm UNUSED, int fm UNUSED)
49 {
50 bool ret = true;
51 UWORD oldval;
52
53 oldval = *eptr;
54 if (__builtin_expect (__kernel_cmpxchg (oldval, newval, mptr) != 0, 0))
55 {
56 oldval = *mptr;
57 ret = false;
58 }
59 *eptr = oldval;
60
61 return ret;
62 }
63 # define atomic_compare_exchange_w atomic_compare_exchange_w
64 # if N == WORDSIZE
65 # define atomic_compare_exchange_n atomic_compare_exchange_w
66 # endif
67 #endif /* HAVE_STREX */
68
69 #if !defined(HAVE_STREXBHD) && defined(HAVE_KERNEL64) && N == 8
70 static inline bool
atomic_compare_exchange_n(UTYPE * mptr,UTYPE * eptr,UTYPE newval,bool weak_p UNUSED,int sm UNUSED,int fm UNUSED)71 atomic_compare_exchange_n (UTYPE *mptr, UTYPE *eptr, UTYPE newval,
72 bool weak_p UNUSED, int sm UNUSED, int fm UNUSED)
73 {
74 if (__kernel_cmpxchg64 (eptr, &newval, mptr) == 0)
75 return true;
76 else
77 {
78 *eptr = *mptr;
79 return false;
80 }
81 }
82 #define atomic_compare_exchange_n atomic_compare_exchange_n
83 #endif
84
85 #if !defined(HAVE_DMB) && !defined(HAVE_DMB_MCR)
86 static inline void
pre_barrier(int model UNUSED)87 pre_barrier(int model UNUSED)
88 {
89 __kernel_dmb ();
90 }
91
92 static inline void
post_barrier(int model UNUSED)93 post_barrier(int model UNUSED)
94 {
95 __kernel_dmb ();
96 }
97 # define pre_post_barrier 1
98 #endif /* !HAVE_DMB */
99
100 #if HAVE_IFUNC
101 extern bool libat_have_strexbhd HIDDEN;
102
103 # define IFUNC_COND_1 libat_have_strexbhd
104 # define IFUNC_COND_2 (__kernel_helper_version >= 5)
105
106 /* Alternative 1 is -march=armv7-a -- we have everything native. */
107 # if IFUNC_ALT == 1
108 # undef HAVE_ATOMIC_CAS_1
109 # undef HAVE_ATOMIC_CAS_2
110 # undef HAVE_ATOMIC_CAS_4
111 # undef HAVE_ATOMIC_CAS_8
112 # undef HAVE_ATOMIC_EXCHANGE_1
113 # undef HAVE_ATOMIC_EXCHANGE_2
114 # undef HAVE_ATOMIC_EXCHANGE_4
115 # undef HAVE_ATOMIC_EXCHANGE_8
116 # undef HAVE_ATOMIC_LDST_1
117 # undef HAVE_ATOMIC_LDST_2
118 # undef HAVE_ATOMIC_LDST_4
119 # undef HAVE_ATOMIC_LDST_8
120 # undef HAVE_ATOMIC_FETCH_OP_1
121 # undef HAVE_ATOMIC_FETCH_OP_2
122 # undef HAVE_ATOMIC_FETCH_OP_4
123 # undef HAVE_ATOMIC_FETCH_OP_8
124 # undef HAVE_ATOMIC_TAS_1
125 # undef HAVE_ATOMIC_TAS_2
126 # undef HAVE_ATOMIC_TAS_4
127 # undef HAVE_ATOMIC_TAS_8
128 # define HAVE_ATOMIC_CAS_1 1
129 # define HAVE_ATOMIC_CAS_2 1
130 # define HAVE_ATOMIC_CAS_4 1
131 # define HAVE_ATOMIC_CAS_8 1
132 # define HAVE_ATOMIC_EXCHANGE_1 1
133 # define HAVE_ATOMIC_EXCHANGE_2 1
134 # define HAVE_ATOMIC_EXCHANGE_4 1
135 # define HAVE_ATOMIC_EXCHANGE_8 1
136 # define HAVE_ATOMIC_LDST_1 1
137 # define HAVE_ATOMIC_LDST_2 1
138 # define HAVE_ATOMIC_LDST_4 1
139 # define HAVE_ATOMIC_LDST_8 1
140 # define HAVE_ATOMIC_FETCH_OP_1 1
141 # define HAVE_ATOMIC_FETCH_OP_2 1
142 # define HAVE_ATOMIC_FETCH_OP_4 1
143 # define HAVE_ATOMIC_FETCH_OP_8 1
144 # define HAVE_ATOMIC_TAS_1 1
145 # define HAVE_ATOMIC_TAS_2 1
146 # define HAVE_ATOMIC_TAS_4 1
147 # define HAVE_ATOMIC_TAS_8 1
148 # endif /* IFUNC_ALT == 1 */
149
150 # undef MAYBE_HAVE_ATOMIC_CAS_1
151 # define MAYBE_HAVE_ATOMIC_CAS_1 IFUNC_COND_1
152 # undef MAYBE_HAVE_ATOMIC_EXCHANGE_1
153 # define MAYBE_HAVE_ATOMIC_EXCHANGE_1 MAYBE_HAVE_ATOMIC_CAS_1
154 # undef MAYBE_HAVE_ATOMIC_LDST_1
155 # define MAYBE_HAVE_ATOMIC_LDST_1 MAYBE_HAVE_ATOMIC_CAS_1
156 # undef MAYBE_HAVE_ATOMIC_CAS_2
157 # define MAYBE_HAVE_ATOMIC_CAS_2 IFUNC_COND_1
158 # undef MAYBE_HAVE_ATOMIC_EXCHANGE_2
159 # define MAYBE_HAVE_ATOMIC_EXCHANGE_2 MAYBE_HAVE_ATOMIC_CAS_2
160 # undef MAYBE_HAVE_ATOMIC_LDST_2
161 # define MAYBE_HAVE_ATOMIC_LDST_2 MAYBE_HAVE_ATOMIC_CAS_2
162 # undef MAYBE_HAVE_ATOMIC_CAS_4
163 # define MAYBE_HAVE_ATOMIC_CAS_4 IFUNC_COND_1
164 # undef MAYBE_HAVE_ATOMIC_EXCHANGE_4
165 # define MAYBE_HAVE_ATOMIC_EXCHANGE_4 MAYBE_HAVE_ATOMIC_CAS_4
166 # undef MAYBE_HAVE_ATOMIC_LDST_4
167 # define MAYBE_HAVE_ATOMIC_LDST_4 MAYBE_HAVE_ATOMIC_CAS_4
168 # undef MAYBE_HAVE_ATOMIC_CAS_8
169 # define MAYBE_HAVE_ATOMIC_CAS_8 (IFUNC_COND_1 | IFUNC_COND_2)
170 # undef MAYBE_HAVE_ATOMIC_EXCHANGE_8
171 # define MAYBE_HAVE_ATOMIC_EXCHANGE_8 MAYBE_HAVE_ATOMIC_CAS_8
172 # undef MAYBE_HAVE_ATOMIC_LDST_8
173 # define MAYBE_HAVE_ATOMIC_LDST_8 MAYBE_HAVE_ATOMIC_CAS_8
174
175 # define IFUNC_NCOND(N) (N == 8 ? 2 : 1)
176
177 #endif /* HAVE_IFUNC */
178
179 #include_next <host-config.h>
180