linux/arch/riscv/kernel/time.c
Andrew Jones 323925ed6d RISC-V: paravirt: Add skeleton for pv-time support
Add the files and functions needed to support paravirt time on
RISC-V. Also include the common code needed for the first
application of pv-time, which is steal-time. In the next
patches we'll complete the functions to fully enable steal-time
support.

Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-12-30 11:25:03 +05:30

52 lines
1.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 Regents of the University of California
* Copyright (C) 2017 SiFive
*/
#include <linux/acpi.h>
#include <linux/of_clk.h>
#include <linux/clockchips.h>
#include <linux/clocksource.h>
#include <linux/delay.h>
#include <asm/sbi.h>
#include <asm/processor.h>
#include <asm/timex.h>
#include <asm/paravirt.h>
unsigned long riscv_timebase __ro_after_init;
EXPORT_SYMBOL_GPL(riscv_timebase);
void __init time_init(void)
{
struct device_node *cpu;
struct acpi_table_rhct *rhct;
acpi_status status;
u32 prop;
if (acpi_disabled) {
cpu = of_find_node_by_path("/cpus");
if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
panic("RISC-V system with no 'timebase-frequency' in DTS\n");
of_node_put(cpu);
riscv_timebase = prop;
of_clk_init(NULL);
} else {
status = acpi_get_table(ACPI_SIG_RHCT, 0, (struct acpi_table_header **)&rhct);
if (ACPI_FAILURE(status))
panic("RISC-V ACPI system with no RHCT table\n");
riscv_timebase = rhct->time_base_freq;
acpi_put_table((struct acpi_table_header *)rhct);
}
lpj_fine = riscv_timebase / HZ;
timer_probe();
tick_setup_hrtimer_broadcast();
pv_time_init();
}