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] __section(".data");
19 void *__cpu_up_task_pointer[NR_CPUS] __section(".data");
20 
21 extern const struct cpu_operations cpu_ops_sbi;
22 extern const struct cpu_operations cpu_ops_spinwait;
23 
cpu_update_secondary_bootdata(unsigned int cpuid,struct task_struct * tidle)24 void cpu_update_secondary_bootdata(unsigned int cpuid,
25 				   struct task_struct *tidle)
26 {
27 	int hartid = cpuid_to_hartid_map(cpuid);
28 
29 	/* Make sure tidle is updated */
30 	smp_mb();
31 	WRITE_ONCE(__cpu_up_stack_pointer[hartid],
32 		   task_stack_page(tidle) + THREAD_SIZE);
33 	WRITE_ONCE(__cpu_up_task_pointer[hartid], tidle);
34 }
35 
cpu_set_ops(int cpuid)36 void __init cpu_set_ops(int cpuid)
37 {
38 #if IS_ENABLED(CONFIG_RISCV_SBI)
39 	if (sbi_probe_extension(SBI_EXT_HSM) > 0) {
40 		if (!cpuid)
41 			pr_info("SBI v0.2 HSM extension detected\n");
42 		cpu_ops[cpuid] = &cpu_ops_sbi;
43 	} else
44 #endif
45 		cpu_ops[cpuid] = &cpu_ops_spinwait;
46 }
47