mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-24 09:25:45 +07:00
2875fe0561
Currently, all non-booting harts start booting after the booting hart updates the per-hart stack pointer. This is done in a way that, it's difficult to implement any other booting method without breaking the backward compatibility. Define a cpu_ops method that allows to introduce other booting methods in future. Modify the current booting method to be compatible with cpu_ops. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
44 lines
1.1 KiB
C
44 lines
1.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Copyright (c) 2020 Western Digital Corporation or its affiliates.
|
|
*/
|
|
|
|
#include <linux/errno.h>
|
|
#include <linux/of.h>
|
|
#include <linux/string.h>
|
|
#include <asm/cpu_ops.h>
|
|
#include <asm/sbi.h>
|
|
#include <asm/smp.h>
|
|
|
|
const struct cpu_operations cpu_ops_spinwait;
|
|
|
|
static int spinwait_cpu_prepare(unsigned int cpuid)
|
|
{
|
|
if (!cpu_ops_spinwait.cpu_start) {
|
|
pr_err("cpu start method not defined for CPU [%d]\n", cpuid);
|
|
return -ENODEV;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int spinwait_cpu_start(unsigned int cpuid, struct task_struct *tidle)
|
|
{
|
|
/*
|
|
* In this protocol, all cpus boot on their own accord. _start
|
|
* selects the first cpu to boot the kernel and causes the remainder
|
|
* of the cpus to spin in a loop waiting for their stack pointer to be
|
|
* setup by that main cpu. Writing to bootdata
|
|
* (i.e __cpu_up_stack_pointer) signals to the spinning cpus that they
|
|
* can continue the boot process.
|
|
*/
|
|
cpu_update_secondary_bootdata(cpuid, tidle);
|
|
|
|
return 0;
|
|
}
|
|
|
|
const struct cpu_operations cpu_ops_spinwait = {
|
|
.name = "spinwait",
|
|
.cpu_prepare = spinwait_cpu_prepare,
|
|
.cpu_start = spinwait_cpu_start,
|
|
};
|