1 /* Linux-specific atomic operations for NDS32 Linux.
2 Copyright (C) 2012-2023 Free Software Foundation, Inc.
3
4 This file is free software; you can redistribute it and/or modify it
5 under the terms of the GNU General Public License as published by the
6 Free Software Foundation; either version 3, or (at your option) any
7 later version.
8
9 This file is distributed in the hope that it will be useful, but
10 WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 General Public License for more details.
13
14 Under Section 7 of GPL version 3, you are granted additional
15 permissions described in the GCC Runtime Library Exception, version
16 3.1, as published by the Free Software Foundation.
17
18 You should have received a copy of the GNU General Public License and
19 a copy of the GCC Runtime Library Exception along with this program;
20 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
21 <http://www.gnu.org/licenses/>. */
22
23 /* We implement byte, short and int versions of each atomic operation
24 using the kernel helper defined below. There is no support for
25 64-bit operations yet. */
26
27 /* This function copy form NDS32 Linux-kernal. */
28 static inline int
29 __kernel_cmpxchg (int oldval, int newval, int *mem)
30 {
31 int temp1, temp2, temp3, offset;
32
33 asm volatile ("msync\tall\n"
34 "movi\t%0, #0\n"
35 "1:\n"
36 "\tllw\t%1, [%4+%0]\n"
37 "\tsub\t%3, %1, %6\n"
38 "\tcmovz\t%2, %5, %3\n"
39 "\tcmovn\t%2, %1, %3\n"
40 "\tscw\t%2, [%4+%0]\n"
41 "\tbeqz\t%2, 1b\n"
42 : "=&r" (offset), "=&r" (temp3), "=&r" (temp2), "=&r" (temp1)
43 : "r" (mem), "r" (newval), "r" (oldval) : "memory");
44
45 return temp1;
46 }
47
48 #define HIDDEN __attribute__ ((visibility ("hidden")))
49
50 #ifdef __NDS32_EL__
51 #define INVERT_MASK_1 0
52 #define INVERT_MASK_2 0
53 #else
54 #define INVERT_MASK_1 24
55 #define INVERT_MASK_2 16
56 #endif
57
58 #define MASK_1 0xffu
59 #define MASK_2 0xffffu
60
61 #define FETCH_AND_OP_WORD(OP, PFX_OP, INF_OP) \
62 int HIDDEN \
63 __sync_fetch_and_##OP##_4 (int *ptr, int val) \
64 { \
65 int failure, tmp; \
66 \
67 do { \
68 tmp = __atomic_load_n (ptr, __ATOMIC_SEQ_CST); \
69 failure = __kernel_cmpxchg (tmp, PFX_OP (tmp INF_OP val), ptr); \
70 } while (failure != 0); \
71 \
72 return tmp; \
73 }
74
75 FETCH_AND_OP_WORD (add, , +)
76 FETCH_AND_OP_WORD (sub, , -)
77 FETCH_AND_OP_WORD (or, , |)
78 FETCH_AND_OP_WORD (and, , &)
79 FETCH_AND_OP_WORD (xor, , ^)
80 FETCH_AND_OP_WORD (nand, ~, &)
81
82 #define NAME_oldval(OP, WIDTH) __sync_fetch_and_##OP##_##WIDTH
83 #define NAME_newval(OP, WIDTH) __sync_##OP##_and_fetch_##WIDTH
84
85 /* Implement both __sync_<op>_and_fetch and __sync_fetch_and_<op> for
86 subword-sized quantities. */
87
88 #define SUBWORD_SYNC_OP(OP, PFX_OP, INF_OP, TYPE, WIDTH, RETURN) \
89 TYPE HIDDEN \
90 NAME##_##RETURN (OP, WIDTH) (TYPE *ptr, TYPE val) \
91 { \
92 int *wordptr = (int *) ((unsigned long) ptr & ~3); \
93 unsigned int mask, shift, oldval, newval; \
94 int failure; \
95 \
96 shift = (((unsigned long) ptr & 3) << 3) ^ INVERT_MASK_##WIDTH; \
97 mask = MASK_##WIDTH << shift; \
98 \
99 do { \
100 oldval = __atomic_load_n (wordptr, __ATOMIC_SEQ_CST); \
101 newval = ((PFX_OP (((oldval & mask) >> shift) \
102 INF_OP (unsigned int) val)) << shift) & mask; \
103 newval |= oldval & ~mask; \
104 failure = __kernel_cmpxchg (oldval, newval, wordptr); \
105 } while (failure != 0); \
106 \
107 return (RETURN & mask) >> shift; \
108 }
109
110
111 SUBWORD_SYNC_OP (add, , +, unsigned short, 2, oldval)
112 SUBWORD_SYNC_OP (sub, , -, unsigned short, 2, oldval)
113 SUBWORD_SYNC_OP (or, , |, unsigned short, 2, oldval)
114 SUBWORD_SYNC_OP (and, , &, unsigned short, 2, oldval)
115 SUBWORD_SYNC_OP (xor, , ^, unsigned short, 2, oldval)
116 SUBWORD_SYNC_OP (nand, ~, &, unsigned short, 2, oldval)
117
118 SUBWORD_SYNC_OP (add, , +, unsigned char, 1, oldval)
119 SUBWORD_SYNC_OP (sub, , -, unsigned char, 1, oldval)
120 SUBWORD_SYNC_OP (or, , |, unsigned char, 1, oldval)
121 SUBWORD_SYNC_OP (and, , &, unsigned char, 1, oldval)
122 SUBWORD_SYNC_OP (xor, , ^, unsigned char, 1, oldval)
123 SUBWORD_SYNC_OP (nand, ~, &, unsigned char, 1, oldval)
124
125 #define OP_AND_FETCH_WORD(OP, PFX_OP, INF_OP) \
126 int HIDDEN \
127 __sync_##OP##_and_fetch_4 (int *ptr, int val) \
128 { \
129 int tmp, failure; \
130 \
131 do { \
132 tmp = __atomic_load_n (ptr, __ATOMIC_SEQ_CST); \
133 failure = __kernel_cmpxchg (tmp, PFX_OP (tmp INF_OP val), ptr); \
134 } while (failure != 0); \
135 \
136 return PFX_OP (tmp INF_OP val); \
137 }
138
139 OP_AND_FETCH_WORD (add, , +)
140 OP_AND_FETCH_WORD (sub, , -)
141 OP_AND_FETCH_WORD (or, , |)
142 OP_AND_FETCH_WORD (and, , &)
143 OP_AND_FETCH_WORD (xor, , ^)
144 OP_AND_FETCH_WORD (nand, ~, &)
145
146 SUBWORD_SYNC_OP (add, , +, unsigned short, 2, newval)
147 SUBWORD_SYNC_OP (sub, , -, unsigned short, 2, newval)
148 SUBWORD_SYNC_OP (or, , |, unsigned short, 2, newval)
149 SUBWORD_SYNC_OP (and, , &, unsigned short, 2, newval)
150 SUBWORD_SYNC_OP (xor, , ^, unsigned short, 2, newval)
151 SUBWORD_SYNC_OP (nand, ~, &, unsigned short, 2, newval)
152
153 SUBWORD_SYNC_OP (add, , +, unsigned char, 1, newval)
154 SUBWORD_SYNC_OP (sub, , -, unsigned char, 1, newval)
155 SUBWORD_SYNC_OP (or, , |, unsigned char, 1, newval)
156 SUBWORD_SYNC_OP (and, , &, unsigned char, 1, newval)
157 SUBWORD_SYNC_OP (xor, , ^, unsigned char, 1, newval)
158 SUBWORD_SYNC_OP (nand, ~, &, unsigned char, 1, newval)
159
160 int HIDDEN
161 __sync_val_compare_and_swap_4 (int *ptr, int oldval, int newval)
162 {
163 int actual_oldval, fail;
164
165 while (1)
166 {
167 actual_oldval = __atomic_load_n (ptr, __ATOMIC_SEQ_CST);
168
169 if (oldval != actual_oldval)
170 return actual_oldval;
171
172 fail = __kernel_cmpxchg (actual_oldval, newval, ptr);
173
174 if (!fail)
175 return oldval;
176 }
177 }
178
179 #define SUBWORD_VAL_CAS(TYPE, WIDTH) \
180 TYPE HIDDEN \
181 __sync_val_compare_and_swap_##WIDTH (TYPE *ptr, TYPE oldval, \
182 TYPE newval) \
183 { \
184 int *wordptr = (int *)((unsigned long) ptr & ~3), fail; \
185 unsigned int mask, shift, actual_oldval, actual_newval; \
186 \
187 shift = (((unsigned long) ptr & 3) << 3) ^ INVERT_MASK_##WIDTH; \
188 mask = MASK_##WIDTH << shift; \
189 \
190 while (1) \
191 { \
192 actual_oldval = __atomic_load_n (wordptr, __ATOMIC_SEQ_CST); \
193 \
194 if (((actual_oldval & mask) >> shift) != (unsigned int) oldval) \
195 return (actual_oldval & mask) >> shift; \
196 \
197 actual_newval = (actual_oldval & ~mask) \
198 | (((unsigned int) newval << shift) & mask); \
199 \
200 fail = __kernel_cmpxchg (actual_oldval, actual_newval, \
201 wordptr); \
202 \
203 if (!fail) \
204 return oldval; \
205 } \
206 }
207
208 SUBWORD_VAL_CAS (unsigned short, 2)
209 SUBWORD_VAL_CAS (unsigned char, 1)
210
211 typedef unsigned char bool;
212
213 bool HIDDEN
214 __sync_bool_compare_and_swap_4 (int *ptr, int oldval, int newval)
215 {
216 int failure = __kernel_cmpxchg (oldval, newval, ptr);
217 return (failure == 0);
218 }
219
220 #define SUBWORD_BOOL_CAS(TYPE, WIDTH) \
221 bool HIDDEN \
222 __sync_bool_compare_and_swap_##WIDTH (TYPE *ptr, TYPE oldval, \
223 TYPE newval) \
224 { \
225 TYPE actual_oldval \
226 = __sync_val_compare_and_swap_##WIDTH (ptr, oldval, newval); \
227 return (oldval == actual_oldval); \
228 }
229
230 SUBWORD_BOOL_CAS (unsigned short, 2)
231 SUBWORD_BOOL_CAS (unsigned char, 1)
232
233 int HIDDEN
234 __sync_lock_test_and_set_4 (int *ptr, int val)
235 {
236 int failure, oldval;
237
238 do {
239 oldval = __atomic_load_n (ptr, __ATOMIC_SEQ_CST);
240 failure = __kernel_cmpxchg (oldval, val, ptr);
241 } while (failure != 0);
242
243 return oldval;
244 }
245
246 #define SUBWORD_TEST_AND_SET(TYPE, WIDTH) \
247 TYPE HIDDEN \
248 __sync_lock_test_and_set_##WIDTH (TYPE *ptr, TYPE val) \
249 { \
250 int failure; \
251 unsigned int oldval, newval, shift, mask; \
252 int *wordptr = (int *) ((unsigned long) ptr & ~3); \
253 \
254 shift = (((unsigned long) ptr & 3) << 3) ^ INVERT_MASK_##WIDTH; \
255 mask = MASK_##WIDTH << shift; \
256 \
257 do { \
258 oldval = __atomic_load_n (wordptr, __ATOMIC_SEQ_CST); \
259 newval = (oldval & ~mask) \
260 | (((unsigned int) val << shift) & mask); \
261 failure = __kernel_cmpxchg (oldval, newval, wordptr); \
262 } while (failure != 0); \
263 \
264 return (oldval & mask) >> shift; \
265 }
266
267 SUBWORD_TEST_AND_SET (unsigned short, 2)
268 SUBWORD_TEST_AND_SET (unsigned char, 1)
269
270 #define SYNC_LOCK_RELEASE(TYPE, WIDTH) \
271 void HIDDEN \
272 __sync_lock_release_##WIDTH (TYPE *ptr) \
273 { \
274 /* All writes before this point must be seen before we release \
275 the lock itself. */ \
276 __builtin_nds32_msync_all (); \
277 *ptr = 0; \
278 }
279
280 SYNC_LOCK_RELEASE (int, 4)
281 SYNC_LOCK_RELEASE (short, 2)
282 SYNC_LOCK_RELEASE (char, 1)