1 /* SPDX-License-Identifier: GPL-2.0-only */
2 #ifndef __ASM_VDSO_PROCESSOR_H
3 #define __ASM_VDSO_PROCESSOR_H
4
5 #ifndef __ASSEMBLY__
6
7 #include <asm-generic/barrier.h>
8
9 static inline void cpu_relax(void)
10 {
11 #ifdef __riscv_muldiv
12 int dummy;
13 /* In lieu of a halt instruction, induce a long-latency stall. */
14 __asm__ __volatile__ ("div %0, %0, zero" : "=r" (dummy));
15 #endif
16
17 #ifdef CONFIG_TOOLCHAIN_HAS_ZIHINTPAUSE
18 /*
19 * Reduce instruction retirement.
20 * This assumes the PC changes.
21 */
22 __asm__ __volatile__ ("pause");
23 #else
24 /* Encoding of the pause instruction */
25 __asm__ __volatile__ (".4byte 0x100000F");
26 #endif
27 barrier();
28 }
29
30 #endif /* __ASSEMBLY__ */
31
32 #endif /* __ASM_VDSO_PROCESSOR_H */
33
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