Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * arch/alpha/lib/dec_and_lock.c | |
4 | * | |
5 | * ll/sc version of atomic_dec_and_lock() | |
6 | * | |
7 | */ | |
8 | ||
9 | #include <linux/spinlock.h> | |
60063497 | 10 | #include <linux/atomic.h> |
00fc0e0d | 11 | #include <linux/export.h> |
1da177e4 LT |
12 | |
13 | asm (".text \n\ | |
14 | .global _atomic_dec_and_lock \n\ | |
15 | .ent _atomic_dec_and_lock \n\ | |
16 | .align 4 \n\ | |
17 | _atomic_dec_and_lock: \n\ | |
18 | .prologue 0 \n\ | |
19 | 1: ldl_l $1, 0($16) \n\ | |
20 | subl $1, 1, $1 \n\ | |
21 | beq $1, 2f \n\ | |
22 | stl_c $1, 0($16) \n\ | |
23 | beq $1, 4f \n\ | |
24 | mb \n\ | |
25 | clr $0 \n\ | |
26 | ret \n\ | |
27 | 2: br $29, 3f \n\ | |
28 | 3: ldgp $29, 0($29) \n\ | |
29 | br $atomic_dec_and_lock_1..ng \n\ | |
30 | .subsection 2 \n\ | |
31 | 4: br 1b \n\ | |
32 | .previous \n\ | |
33 | .end _atomic_dec_and_lock"); | |
34 | ||
3ff6eecc | 35 | static int __used atomic_dec_and_lock_1(atomic_t *atomic, spinlock_t *lock) |
1da177e4 LT |
36 | { |
37 | /* Slow path */ | |
38 | spin_lock(lock); | |
39 | if (atomic_dec_and_test(atomic)) | |
40 | return 1; | |
41 | spin_unlock(lock); | |
42 | return 0; | |
43 | } | |
00fc0e0d | 44 | EXPORT_SYMBOL(_atomic_dec_and_lock); |