// SPDX-License-Identifier: GPL-2.0#include <linux/kernel.h>#include <linux/time.h>#include <linux/timer.h>#include <linux/init.h>#include <linux/rtc.h>#include <linux/delay.h>#include <linux/ratelimit.h>#include <asm/rtas.h>#include <asm/time.h>  #define MAX_RTC_WAIT 5000	/* 5 sec */ time64_t __init rtas_get_boot_time(void){	int ret[8];	int error;	unsigned int wait_time;	u64 max_wait_tb; 	max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;	do {		error = rtas_call(rtas_function_token(RTAS_FN_GET_TIME_OF_DAY), 0, 8, ret); 		wait_time = rtas_busy_delay_time(error);		if (wait_time) {			/* This is boot time so we spin. */			udelay(wait_time*1000);		}	} while (wait_time && (get_tb() < max_wait_tb)); 	if (error != 0) {		printk_ratelimited(KERN_WARNING				   "error: reading the clock failed (%d)\n",				   error);		return 0;	} 	return mktime64(ret[0], ret[1], ret[2], ret[3], ret[4], ret[5]);} /* NOTE: get_rtc_time will get an error if executed in interrupt context * and if a delay is needed to read the clock.  In this case we just * silently return without updating rtc_tm. */void rtas_get_rtc_time(struct rtc_time *rtc_tm){        int ret[8];	int error;	unsigned int wait_time;	u64 max_wait_tb; 	max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;	do {		error = rtas_call(rtas_function_token(RTAS_FN_GET_TIME_OF_DAY), 0, 8, ret); 		wait_time = rtas_busy_delay_time(error);		if (wait_time) {			if (in_interrupt()) {				memset(rtc_tm, 0, sizeof(struct rtc_time));				printk_ratelimited(KERN_WARNING						   "error: reading clock "						   "would delay interrupt\n");				return;	/* delay not allowed */			}			msleep(wait_time);		}	} while (wait_time && (get_tb() < max_wait_tb)); 	if (error != 0) {		printk_ratelimited(KERN_WARNING				   "error: reading the clock failed (%d)\n",				   error);		return;        } 	rtc_tm->tm_sec = ret[5];	rtc_tm->tm_min = ret[4];	rtc_tm->tm_hour = ret[3];	rtc_tm->tm_mday = ret[2];	rtc_tm->tm_mon = ret[1] - 1;	rtc_tm->tm_year = ret[0] - 1900;} int rtas_set_rtc_time(struct rtc_time *tm){	int error, wait_time;	u64 max_wait_tb; 	max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;	do {		error = rtas_call(rtas_function_token(RTAS_FN_SET_TIME_OF_DAY), 7, 1, NULL,				  tm->tm_year + 1900, tm->tm_mon + 1,				  tm->tm_mday, tm->tm_hour, tm->tm_min,				  tm->tm_sec, 0); 		wait_time = rtas_busy_delay_time(error);		if (wait_time) {			if (in_interrupt())				return 1;	/* probably decrementer */			msleep(wait_time);		}	} while (wait_time && (get_tb() < max_wait_tb)); 	if (error != 0)		printk_ratelimited(KERN_WARNING				   "error: setting the clock failed (%d)\n",				   error);         return 0;}