xref: /linux/arch/riscv/kernel/cpu_ops.c (revision 2875fe0561569f82d0e63658ccf0d11ce7da8922)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2020 Western Digital Corporation or its affiliates.
4  */
5 
6 #include <linux/errno.h>
7 #include <linux/mm.h>
8 #include <linux/of.h>
9 #include <linux/string.h>
10 #include <linux/sched.h>
11 #include <linux/sched/task_stack.h>
12 #include <asm/cpu_ops.h>
13 #include <asm/sbi.h>
14 #include <asm/smp.h>
15 
16 const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;
17 
18 void *__cpu_up_stack_pointer[NR_CPUS];
19 void *__cpu_up_task_pointer[NR_CPUS];
20 
21 extern const struct cpu_operations cpu_ops_spinwait;
22 
23 void cpu_update_secondary_bootdata(unsigned int cpuid,
24 				   struct task_struct *tidle)
25 {
26 	int hartid = cpuid_to_hartid_map(cpuid);
27 
28 	/* Make sure tidle is updated */
29 	smp_mb();
30 	WRITE_ONCE(__cpu_up_stack_pointer[hartid],
31 		   task_stack_page(tidle) + THREAD_SIZE);
32 	WRITE_ONCE(__cpu_up_task_pointer[hartid], tidle);
33 }
34 
35 void __init cpu_set_ops(int cpuid)
36 {
37 	cpu_ops[cpuid] = &cpu_ops_spinwait;
38 }
39