^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /* SPDX-License-Identifier: GPL-2.0-or-later */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) #ifndef _ASM_POWERPC_DELAY_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) #define _ASM_POWERPC_DELAY_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) #ifdef __KERNEL__
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/processor.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <asm/time.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * Copyright 1996, Paul Mackerras.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * Copyright (C) 2009 Freescale Semiconductor, Inc. All rights reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * PPC64 Support added by Dave Engebretsen, Todd Inglett, Mike Corrigan,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * Anton Blanchard.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) extern void __delay(unsigned long loops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) extern void udelay(unsigned long usecs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * On shared processor machines the generic implementation of mdelay can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * result in large errors. While each iteration of the loop inside mdelay
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) * is supposed to take 1ms, the hypervisor could sleep our partition for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * longer (eg 10ms). With the right timing these errors can add up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * Since there is no 32bit overflow issue on 64bit kernels, just call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * udelay directly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #ifdef CONFIG_PPC64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #define mdelay(n) udelay((n) * 1000)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) * spin_event_timeout - spin until a condition gets true or a timeout elapses
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) * @condition: a C expression to evalate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) * @timeout: timeout, in microseconds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) * @delay: the number of microseconds to delay between each evaluation of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) * @condition
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * The process spins until the condition evaluates to true (non-zero) or the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) * timeout elapses. The return value of this macro is the value of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) * @condition when the loop terminates. This allows you to determine the cause
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) * of the loop terminates. If the return value is zero, then you know a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) * timeout has occurred.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) * This primary purpose of this macro is to poll on a hardware register
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) * until a status bit changes. The timeout ensures that the loop still
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) * terminates even if the bit never changes. The delay is for devices that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) * need a delay in between successive reads.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) * gcc will optimize out the if-statement if @delay is a constant.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) #define spin_event_timeout(condition, timeout, delay) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) ({ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) typeof(condition) __ret; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) unsigned long __loops = tb_ticks_per_usec * timeout; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) unsigned long __start = mftb(); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) if (delay) { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) while (!(__ret = (condition)) && \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) (tb_ticks_since(__start) <= __loops)) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) udelay(delay); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) } else { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) spin_begin(); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) while (!(__ret = (condition)) && \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) (tb_ticks_since(__start) <= __loops)) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) spin_cpu_relax(); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) spin_end(); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) } \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) if (!__ret) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) __ret = (condition); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) __ret; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) })
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) #endif /* __KERNEL__ */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) #endif /* _ASM_POWERPC_DELAY_H */
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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