linux/arch/riscv/kernel/cpu_ops_sbi.c
Samuel Holland 79093f3ec3
riscv: Remove unused members from struct cpu_operations
name is not used anywhere at all. cpu_prepare and cpu_disable do nothing
and always return 0 if implemented.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20231121234736.3489608-3-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-04 15:03:06 -08:00

111 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* HSM extension and cpu_ops implementation.
*
* Copyright (c) 2020 Western Digital Corporation or its affiliates.
*/
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/sched/task_stack.h>
#include <asm/cpu_ops.h>
#include <asm/cpu_ops_sbi.h>
#include <asm/sbi.h>
#include <asm/smp.h>
extern char secondary_start_sbi[];
const struct cpu_operations cpu_ops_sbi;
/*
* Ordered booting via HSM brings one cpu at a time. However, cpu hotplug can
* be invoked from multiple threads in parallel. Define a per cpu data
* to handle that.
*/
static DEFINE_PER_CPU(struct sbi_hart_boot_data, boot_data);
static int sbi_hsm_hart_start(unsigned long hartid, unsigned long saddr,
unsigned long priv)
{
struct sbiret ret;
ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_START,
hartid, saddr, priv, 0, 0, 0);
if (ret.error)
return sbi_err_map_linux_errno(ret.error);
else
return 0;
}
#ifdef CONFIG_HOTPLUG_CPU
static int sbi_hsm_hart_stop(void)
{
struct sbiret ret;
ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_STOP, 0, 0, 0, 0, 0, 0);
if (ret.error)
return sbi_err_map_linux_errno(ret.error);
else
return 0;
}
static int sbi_hsm_hart_get_status(unsigned long hartid)
{
struct sbiret ret;
ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_STATUS,
hartid, 0, 0, 0, 0, 0);
if (ret.error)
return sbi_err_map_linux_errno(ret.error);
else
return ret.value;
}
#endif
static int sbi_cpu_start(unsigned int cpuid, struct task_struct *tidle)
{
unsigned long boot_addr = __pa_symbol(secondary_start_sbi);
unsigned long hartid = cpuid_to_hartid_map(cpuid);
unsigned long hsm_data;
struct sbi_hart_boot_data *bdata = &per_cpu(boot_data, cpuid);
/* Make sure tidle is updated */
smp_mb();
bdata->task_ptr = tidle;
bdata->stack_ptr = task_stack_page(tidle) + THREAD_SIZE;
/* Make sure boot data is updated */
smp_mb();
hsm_data = __pa(bdata);
return sbi_hsm_hart_start(hartid, boot_addr, hsm_data);
}
#ifdef CONFIG_HOTPLUG_CPU
static void sbi_cpu_stop(void)
{
int ret;
ret = sbi_hsm_hart_stop();
pr_crit("Unable to stop the cpu %u (%d)\n", smp_processor_id(), ret);
}
static int sbi_cpu_is_stopped(unsigned int cpuid)
{
int rc;
unsigned long hartid = cpuid_to_hartid_map(cpuid);
rc = sbi_hsm_hart_get_status(hartid);
if (rc == SBI_HSM_STATE_STOPPED)
return 0;
return rc;
}
#endif
const struct cpu_operations cpu_ops_sbi = {
.cpu_start = sbi_cpu_start,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_stop = sbi_cpu_stop,
.cpu_is_stopped = sbi_cpu_is_stopped,
#endif
};