Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) /* SPDX-License-Identifier: GPL-2.0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * Copyright (C) 2019 Google LLC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) #ifndef __ASM_RWONCE_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) #define __ASM_RWONCE_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) #ifdef CONFIG_SMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <asm/barrier.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  * Alpha is apparently daft enough to reorder address-dependent loads
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  * on some CPU implementations. Knock some common sense into it with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  * a memory barrier in READ_ONCE().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)  * For the curious, more information about this unusual reordering is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)  * available in chapter 15 of the "perfbook":
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)  *  https://kernel.org/pub/linux/kernel/people/paulmck/perfbook/perfbook.html
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #define __READ_ONCE(x)							\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) ({									\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 	__unqual_scalar_typeof(x) __x =					\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 		(*(volatile typeof(__x) *)(&(x)));			\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	mb();								\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	(typeof(x))__x;							\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) })
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #endif /* CONFIG_SMP */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #include <asm-generic/rwonce.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #endif /* __ASM_RWONCE_H */