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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_SPARC_VDSO_PROCESSOR_H
#define _ASM_SPARC_VDSO_PROCESSOR_H
#include <linux/compiler.h>
#if defined(__arch64__)
/* Please see the commentary in asm/backoff.h for a description of
* what these instructions are doing and how they have been chosen.
* To make a long story short, we are trying to yield the current cpu
* strand during busy loops.
*/
#ifdef BUILD_VDSO
#define cpu_relax() asm volatile("\n99:\n\t" \
"rd %%ccr, %%g0\n\t" \
"rd %%ccr, %%g0\n\t" \
"rd %%ccr, %%g0\n\t" \
::: "memory")
#else /* ! BUILD_VDSO */
#define cpu_relax() asm volatile("\n99:\n\t" \
"rd %%ccr, %%g0\n\t" \
"rd %%ccr, %%g0\n\t" \
"rd %%ccr, %%g0\n\t" \
".section .pause_3insn_patch,\"ax\"\n\t"\
".word 99b\n\t" \
"wr %%g0, 128, %%asr27\n\t" \
"nop\n\t" \
"nop\n\t" \
".previous" \
::: "memory")
#endif /* BUILD_VDSO */
#else /* ! __arch64__ */
#define cpu_relax() barrier()
#endif /* __arch64__ */
#endif /* _ASM_SPARC_VDSO_PROCESSOR_H */
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