xref: /kvm-unit-tests/lib/riscv/smp.c (revision 386ed5c2f9e98a2605817748c44c0cefa60dc88e)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Boot secondary CPUs
4  *
5  * Copyright (C) 2023, Ventana Micro Systems Inc., Andrew Jones <ajones@ventanamicro.com>
6  */
7 #include <libcflat.h>
8 #include <alloc_page.h>
9 #include <cpumask.h>
10 #include <asm/csr.h>
11 #include <asm/mmu.h>
12 #include <asm/page.h>
13 #include <asm/processor.h>
14 #include <asm/sbi.h>
15 #include <asm/smp.h>
16 
17 cpumask_t cpu_present_mask;
18 cpumask_t cpu_online_mask;
19 cpumask_t cpu_idle_mask;
20 
21 static cpumask_t cpu_started;
22 
23 secondary_func_t secondary_cinit(struct secondary_data *data)
24 {
25 	struct thread_info *info;
26 
27 	__mmu_enable(data->satp);
28 	thread_info_init();
29 	info = current_thread_info();
30 	set_cpu_online(info->cpu, true);
31 	smp_send_event();
32 
33 	return data->func;
34 }
35 
36 static void __smp_boot_secondary(int cpu, secondary_func_t func)
37 {
38 	struct secondary_data *sp = alloc_pages(1) + SZ_8K - 16;
39 	struct sbiret ret;
40 
41 	sp -= sizeof(struct secondary_data);
42 	sp->satp = csr_read(CSR_SATP);
43 	sp->stvec = csr_read(CSR_STVEC);
44 	sp->func = func;
45 
46 	ret = sbi_hart_start(cpus[cpu].hartid, (unsigned long)&secondary_entry, __pa(sp));
47 	assert(ret.error == SBI_SUCCESS);
48 }
49 
50 void smp_boot_secondary(int cpu, void (*func)(void))
51 {
52 	int ret = cpumask_test_and_set_cpu(cpu, &cpu_started);
53 
54 	assert_msg(!ret, "CPU%d already boot once", cpu);
55 	__smp_boot_secondary(cpu, func);
56 
57 	while (!cpu_online(cpu))
58 		smp_wait_for_event();
59 }
60 
61 void smp_boot_secondary_nofail(int cpu, void (*func)(void))
62 {
63 	int ret = cpumask_test_and_set_cpu(cpu, &cpu_started);
64 
65 	if (!ret)
66 		__smp_boot_secondary(cpu, func);
67 
68 	while (!cpu_online(cpu))
69 		smp_wait_for_event();
70 }
71