opensbi/lib/sbi_timer.c

/*
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2019 Western Digital Corporation or its affiliates.
 *
 * Authors:
 *   Anup Patel <anup.patel@wdc.com>
 */

#include <sbi/riscv_asm.h>
#include <sbi/riscv_encoding.h>
#include <sbi/sbi_platform.h>
#include <sbi/sbi_timer.h>

#if __riscv_xlen == 32
u64 get_ticks(void)
{
	u32 lo, hi, tmp;
	__asm__ __volatile__ (
		"1:\n"
		"rdtimeh %0\n"
		"rdtime %1\n"
		"rdtimeh %2\n"
		"bne %0, %2, 1b"
		: "=&r" (hi), "=&r" (lo), "=&r" (tmp));
	return ((u64)hi << 32) | lo;
}
#else
u64 get_ticks(void)
{
	unsigned long n;

	__asm__ __volatile__ (
		"rdtime %0"
		: "=r" (n));
	return n;
}
#endif

u64 sbi_timer_value(struct sbi_scratch *scratch)
{
	struct sbi_platform *plat = sbi_platform_ptr(scratch);

	if (sbi_platform_has_timer_value(plat))
		return sbi_platform_timer_value(plat);
	else
		return get_ticks();
}

void sbi_timer_event_stop(struct sbi_scratch *scratch)
{
	sbi_platform_timer_event_stop(sbi_platform_ptr(scratch));
}

void sbi_timer_event_start(struct sbi_scratch *scratch, u64 next_event)
{
	sbi_platform_timer_event_start(sbi_platform_ptr(scratch),
				       next_event);
	csr_clear(CSR_MIP, MIP_STIP);
	csr_set(CSR_MIE, MIP_MTIP);
}

void sbi_timer_process(struct sbi_scratch *scratch)
{
	csr_clear(CSR_MIE, MIP_MTIP);
	csr_set(CSR_MIP, MIP_STIP);
}

int sbi_timer_init(struct sbi_scratch *scratch, bool cold_boot)
{
	return sbi_platform_timer_init(sbi_platform_ptr(scratch),
				       cold_boot);
}