1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
|
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2014 Regents of the University of California
*/
#ifndef _ASM_RISCV_CMPXCHG_H
#define _ASM_RISCV_CMPXCHG_H
#include <linux/bug.h>
#include <asm/alternative-macros.h>
#include <asm/fence.h>
#include <asm/hwcap.h>
#include <asm/insn-def.h>
#include <asm/cpufeature-macros.h>
#include <asm/processor.h>
#include <asm/errata_list.h>
#define __arch_xchg_masked(sc_sfx, swap_sfx, prepend, sc_append, \
swap_append, r, p, n) \
({ \
if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) && \
riscv_has_extension_unlikely(RISCV_ISA_EXT_ZABHA)) { \
__asm__ __volatile__ ( \
prepend \
" amoswap" swap_sfx " %0, %z2, %1\n" \
swap_append \
: "=&r" (r), "+A" (*(p)) \
: "rJ" (n) \
: "memory"); \
} else { \
u32 *__ptr32b = (u32 *)((ulong)(p) & ~0x3); \
ulong __s = ((ulong)(p) & (0x4 - sizeof(*p))) * BITS_PER_BYTE; \
ulong __mask = GENMASK(((sizeof(*p)) * BITS_PER_BYTE) - 1, 0) \
<< __s; \
ulong __newx = (ulong)(n) << __s; \
ulong __retx; \
ulong __rc; \
\
__asm__ __volatile__ ( \
prepend \
PREFETCHW_ASM(%5) \
"0: lr.w %0, %2\n" \
" and %1, %0, %z4\n" \
" or %1, %1, %z3\n" \
" sc.w" sc_sfx " %1, %1, %2\n" \
" bnez %1, 0b\n" \
sc_append \
: "=&r" (__retx), "=&r" (__rc), "+A" (*(__ptr32b)) \
: "rJ" (__newx), "rJ" (~__mask), "rJ" (__ptr32b) \
: "memory"); \
\
r = (__typeof__(*(p)))((__retx & __mask) >> __s); \
} \
})
#define __arch_xchg(sfx, prepend, append, r, p, n) \
({ \
__asm__ __volatile__ ( \
prepend \
" amoswap" sfx " %0, %2, %1\n" \
append \
: "=r" (r), "+A" (*(p)) \
: "r" (n) \
: "memory"); \
})
#define _arch_xchg(ptr, new, sc_sfx, swap_sfx, prepend, \
sc_append, swap_append) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(*(__ptr)) __new = (new); \
__typeof__(*(__ptr)) __ret; \
\
switch (sizeof(*__ptr)) { \
case 1: \
__arch_xchg_masked(sc_sfx, ".b" swap_sfx, \
prepend, sc_append, swap_append, \
__ret, __ptr, __new); \
break; \
case 2: \
__arch_xchg_masked(sc_sfx, ".h" swap_sfx, \
prepend, sc_append, swap_append, \
__ret, __ptr, __new); \
break; \
case 4: \
__arch_xchg(".w" swap_sfx, prepend, swap_append, \
__ret, __ptr, __new); \
break; \
case 8: \
__arch_xchg(".d" swap_sfx, prepend, swap_append, \
__ret, __ptr, __new); \
break; \
default: \
BUILD_BUG(); \
} \
(__typeof__(*(__ptr)))__ret; \
})
#define arch_xchg_relaxed(ptr, x) \
_arch_xchg(ptr, x, "", "", "", "", "")
#define arch_xchg_acquire(ptr, x) \
_arch_xchg(ptr, x, "", "", "", \
RISCV_ACQUIRE_BARRIER, RISCV_ACQUIRE_BARRIER)
#define arch_xchg_release(ptr, x) \
_arch_xchg(ptr, x, "", "", RISCV_RELEASE_BARRIER, "", "")
#define arch_xchg(ptr, x) \
_arch_xchg(ptr, x, ".rl", ".aqrl", "", RISCV_FULL_BARRIER, "")
#define xchg32(ptr, x) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 4); \
arch_xchg((ptr), (x)); \
})
#define xchg64(ptr, x) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
arch_xchg((ptr), (x)); \
})
/*
* Atomic compare and exchange. Compare OLD with MEM, if identical,
* store NEW in MEM. Return the initial value in MEM. Success is
* indicated by comparing RETURN with OLD.
*/
#define __arch_cmpxchg_masked(sc_sfx, cas_sfx, \
sc_prepend, sc_append, \
cas_prepend, cas_append, \
r, p, o, n) \
({ \
if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) && \
IS_ENABLED(CONFIG_RISCV_ISA_ZACAS) && \
IS_ENABLED(CONFIG_TOOLCHAIN_HAS_ZACAS) && \
riscv_has_extension_unlikely(RISCV_ISA_EXT_ZABHA) && \
riscv_has_extension_unlikely(RISCV_ISA_EXT_ZACAS)) { \
r = o; \
\
__asm__ __volatile__ ( \
cas_prepend \
" amocas" cas_sfx " %0, %z2, %1\n" \
cas_append \
: "+&r" (r), "+A" (*(p)) \
: "rJ" (n) \
: "memory"); \
} else { \
u32 *__ptr32b = (u32 *)((ulong)(p) & ~0x3); \
ulong __s = ((ulong)(p) & (0x4 - sizeof(*p))) * BITS_PER_BYTE; \
ulong __mask = GENMASK(((sizeof(*p)) * BITS_PER_BYTE) - 1, 0) \
<< __s; \
ulong __newx = (ulong)(n) << __s; \
ulong __oldx = (ulong)(o) << __s; \
ulong __retx; \
ulong __rc; \
\
__asm__ __volatile__ ( \
sc_prepend \
"0: lr.w %0, %2\n" \
" and %1, %0, %z5\n" \
" bne %1, %z3, 1f\n" \
" and %1, %0, %z6\n" \
" or %1, %1, %z4\n" \
" sc.w" sc_sfx " %1, %1, %2\n" \
" bnez %1, 0b\n" \
sc_append \
"1:\n" \
: "=&r" (__retx), "=&r" (__rc), "+A" (*(__ptr32b)) \
: "rJ" ((long)__oldx), "rJ" (__newx), \
"rJ" (__mask), "rJ" (~__mask) \
: "memory"); \
\
r = (__typeof__(*(p)))((__retx & __mask) >> __s); \
} \
})
#define __arch_cmpxchg(lr_sfx, sc_sfx, cas_sfx, \
sc_prepend, sc_append, \
cas_prepend, cas_append, \
r, p, co, o, n) \
({ \
if (IS_ENABLED(CONFIG_RISCV_ISA_ZACAS) && \
IS_ENABLED(CONFIG_TOOLCHAIN_HAS_ZACAS) && \
riscv_has_extension_unlikely(RISCV_ISA_EXT_ZACAS)) { \
r = o; \
\
__asm__ __volatile__ ( \
cas_prepend \
" amocas" cas_sfx " %0, %z2, %1\n" \
cas_append \
: "+&r" (r), "+A" (*(p)) \
: "rJ" (n) \
: "memory"); \
} else { \
register unsigned int __rc; \
\
__asm__ __volatile__ ( \
sc_prepend \
"0: lr" lr_sfx " %0, %2\n" \
" bne %0, %z3, 1f\n" \
" sc" sc_sfx " %1, %z4, %2\n" \
" bnez %1, 0b\n" \
sc_append \
"1:\n" \
: "=&r" (r), "=&r" (__rc), "+A" (*(p)) \
: "rJ" (co o), "rJ" (n) \
: "memory"); \
} \
})
#define _arch_cmpxchg(ptr, old, new, sc_sfx, cas_sfx, \
sc_prepend, sc_append, \
cas_prepend, cas_append) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(*(__ptr)) __old = (old); \
__typeof__(*(__ptr)) __new = (new); \
__typeof__(*(__ptr)) __ret; \
\
switch (sizeof(*__ptr)) { \
case 1: \
__arch_cmpxchg_masked(sc_sfx, ".b" cas_sfx, \
sc_prepend, sc_append, \
cas_prepend, cas_append, \
__ret, __ptr, __old, __new); \
break; \
case 2: \
__arch_cmpxchg_masked(sc_sfx, ".h" cas_sfx, \
sc_prepend, sc_append, \
cas_prepend, cas_append, \
__ret, __ptr, __old, __new); \
break; \
case 4: \
__arch_cmpxchg(".w", ".w" sc_sfx, ".w" cas_sfx, \
sc_prepend, sc_append, \
cas_prepend, cas_append, \
__ret, __ptr, (long)(int)(long), __old, __new); \
break; \
case 8: \
__arch_cmpxchg(".d", ".d" sc_sfx, ".d" cas_sfx, \
sc_prepend, sc_append, \
cas_prepend, cas_append, \
__ret, __ptr, /**/, __old, __new); \
break; \
default: \
BUILD_BUG(); \
} \
(__typeof__(*(__ptr)))__ret; \
})
/*
* These macros are here to improve the readability of the arch_cmpxchg_XXX()
* macros.
*/
#define SC_SFX(x) x
#define CAS_SFX(x) x
#define SC_PREPEND(x) x
#define SC_APPEND(x) x
#define CAS_PREPEND(x) x
#define CAS_APPEND(x) x
#define arch_cmpxchg_relaxed(ptr, o, n) \
_arch_cmpxchg((ptr), (o), (n), \
SC_SFX(""), CAS_SFX(""), \
SC_PREPEND(""), SC_APPEND(""), \
CAS_PREPEND(""), CAS_APPEND(""))
#define arch_cmpxchg_acquire(ptr, o, n) \
_arch_cmpxchg((ptr), (o), (n), \
SC_SFX(""), CAS_SFX(""), \
SC_PREPEND(""), SC_APPEND(RISCV_ACQUIRE_BARRIER), \
CAS_PREPEND(""), CAS_APPEND(RISCV_ACQUIRE_BARRIER))
#define arch_cmpxchg_release(ptr, o, n) \
_arch_cmpxchg((ptr), (o), (n), \
SC_SFX(""), CAS_SFX(""), \
SC_PREPEND(RISCV_RELEASE_BARRIER), SC_APPEND(""), \
CAS_PREPEND(RISCV_RELEASE_BARRIER), CAS_APPEND(""))
#define arch_cmpxchg(ptr, o, n) \
_arch_cmpxchg((ptr), (o), (n), \
SC_SFX(".rl"), CAS_SFX(".aqrl"), \
SC_PREPEND(""), SC_APPEND(RISCV_FULL_BARRIER), \
CAS_PREPEND(""), CAS_APPEND(""))
#define arch_cmpxchg_local(ptr, o, n) \
arch_cmpxchg_relaxed((ptr), (o), (n))
#define arch_cmpxchg64(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
arch_cmpxchg((ptr), (o), (n)); \
})
#define arch_cmpxchg64_local(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
arch_cmpxchg_relaxed((ptr), (o), (n)); \
})
#define arch_cmpxchg64_relaxed(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
arch_cmpxchg_relaxed((ptr), (o), (n)); \
})
#define arch_cmpxchg64_acquire(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
arch_cmpxchg_acquire((ptr), (o), (n)); \
})
#define arch_cmpxchg64_release(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
arch_cmpxchg_release((ptr), (o), (n)); \
})
#if defined(CONFIG_64BIT) && defined(CONFIG_RISCV_ISA_ZACAS) && defined(CONFIG_TOOLCHAIN_HAS_ZACAS)
#define system_has_cmpxchg128() riscv_has_extension_unlikely(RISCV_ISA_EXT_ZACAS)
union __u128_halves {
u128 full;
struct {
u64 low, high;
};
};
#define __arch_cmpxchg128(p, o, n, cas_sfx) \
({ \
__typeof__(*(p)) __o = (o); \
union __u128_halves __hn = { .full = (n) }; \
union __u128_halves __ho = { .full = (__o) }; \
register unsigned long t1 asm ("t1") = __hn.low; \
register unsigned long t2 asm ("t2") = __hn.high; \
register unsigned long t3 asm ("t3") = __ho.low; \
register unsigned long t4 asm ("t4") = __ho.high; \
\
__asm__ __volatile__ ( \
" amocas.q" cas_sfx " %0, %z3, %2" \
: "+&r" (t3), "+&r" (t4), "+A" (*(p)) \
: "rJ" (t1), "rJ" (t2) \
: "memory"); \
\
((u128)t4 << 64) | t3; \
})
#define arch_cmpxchg128(ptr, o, n) \
__arch_cmpxchg128((ptr), (o), (n), ".aqrl")
#define arch_cmpxchg128_local(ptr, o, n) \
__arch_cmpxchg128((ptr), (o), (n), "")
#endif /* CONFIG_64BIT && CONFIG_RISCV_ISA_ZACAS && CONFIG_TOOLCHAIN_HAS_ZACAS */
#ifdef CONFIG_RISCV_ISA_ZAWRS
/*
* Despite wrs.nto being "WRS-with-no-timeout", in the absence of changes to
* @val we expect it to still terminate within a "reasonable" amount of time
* for an implementation-specific other reason, a pending, locally-enabled
* interrupt, or because it has been configured to raise an illegal
* instruction exception.
*/
static __always_inline void __cmpwait(volatile void *ptr,
unsigned long val,
int size)
{
unsigned long tmp;
u32 *__ptr32b;
ulong __s, __val, __mask;
asm goto(ALTERNATIVE("j %l[no_zawrs]", "nop",
0, RISCV_ISA_EXT_ZAWRS, 1)
: : : : no_zawrs);
switch (size) {
case 1:
__ptr32b = (u32 *)((ulong)(ptr) & ~0x3);
__s = ((ulong)(ptr) & 0x3) * BITS_PER_BYTE;
__val = val << __s;
__mask = 0xff << __s;
asm volatile(
" lr.w %0, %1\n"
" and %0, %0, %3\n"
" xor %0, %0, %2\n"
" bnez %0, 1f\n"
ZAWRS_WRS_NTO "\n"
"1:"
: "=&r" (tmp), "+A" (*(__ptr32b))
: "r" (__val), "r" (__mask)
: "memory");
break;
case 2:
__ptr32b = (u32 *)((ulong)(ptr) & ~0x3);
__s = ((ulong)(ptr) & 0x2) * BITS_PER_BYTE;
__val = val << __s;
__mask = 0xffff << __s;
asm volatile(
" lr.w %0, %1\n"
" and %0, %0, %3\n"
" xor %0, %0, %2\n"
" bnez %0, 1f\n"
ZAWRS_WRS_NTO "\n"
"1:"
: "=&r" (tmp), "+A" (*(__ptr32b))
: "r" (__val), "r" (__mask)
: "memory");
break;
case 4:
asm volatile(
" lr.w %0, %1\n"
" xor %0, %0, %2\n"
" bnez %0, 1f\n"
ZAWRS_WRS_NTO "\n"
"1:"
: "=&r" (tmp), "+A" (*(u32 *)ptr)
: "r" (val));
break;
#if __riscv_xlen == 64
case 8:
asm volatile(
" lr.d %0, %1\n"
" xor %0, %0, %2\n"
" bnez %0, 1f\n"
ZAWRS_WRS_NTO "\n"
"1:"
: "=&r" (tmp), "+A" (*(u64 *)ptr)
: "r" (val));
break;
#endif
default:
BUILD_BUG();
}
return;
no_zawrs:
ALT_RISCV_PAUSE();
}
#define __cmpwait_relaxed(ptr, val) \
__cmpwait((ptr), (unsigned long)(val), sizeof(*(ptr)))
#endif
#endif /* _ASM_RISCV_CMPXCHG_H */
|
