| 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | /* |
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| 3 | * ARM64 Spinlock support |
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| 4 | */ |
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| 5 | #include <stdint.h> |
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| 6 | |
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| 7 | #include "spinlock.h" |
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| 8 | |
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| 9 | void spin_lock(struct spinlock *lock) |
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| 10 | { |
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| 11 | int val, res; |
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| 12 | |
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| 13 | asm volatile( |
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| 14 | "1: ldaxr %w0, [%2]\n" |
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| 15 | " cbnz %w0, 1b\n" |
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| 16 | " mov %w0, #1\n" |
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| 17 | " stxr %w1, %w0, [%2]\n" |
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| 18 | " cbnz %w1, 1b\n" |
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| 19 | : "=&r" (val), "=&r" (res) |
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| 20 | : "r" (&lock->v) |
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| 21 | : "memory" ); |
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| 22 | } |
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| 23 | |
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| 24 | void spin_unlock(struct spinlock *lock) |
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| 25 | { |
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| 26 | asm volatile("stlr wzr, [%0]\n" : : "r" (&lock->v) : "memory" ); |
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| 27 | } |
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| 28 | |
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