xref: /kvm-unit-tests/lib/riscv/smp.c (revision 2479ae507a7e89903c067d89b476bb27e48875fe)
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.h>
9 #include <cpumask.h>
10 #include <asm/csr.h>
11 #include <asm/page.h>
12 #include <asm/processor.h>
13 #include <asm/sbi.h>
14 #include <asm/smp.h>
15 
16 cpumask_t cpu_present_mask;
17 cpumask_t cpu_online_mask;
18 cpumask_t cpu_idle_mask;
19 
20 static cpumask_t cpu_started;
21 
22 secondary_func_t secondary_cinit(struct secondary_data *data)
23 {
24 	struct thread_info *info;
25 
26 	thread_info_init();
27 	info = current_thread_info();
28 	set_cpu_online(info->cpu, true);
29 	smp_send_event();
30 
31 	return data->func;
32 }
33 
34 static void __smp_boot_secondary(int cpu, secondary_func_t func)
35 {
36 	struct secondary_data *sp = memalign(16, SZ_8K) + SZ_8K - 16;
37 	struct sbiret ret;
38 
39 	sp -= sizeof(struct secondary_data);
40 	sp->stvec = csr_read(CSR_STVEC);
41 	sp->func = func;
42 
43 	ret = sbi_hart_start(cpus[cpu].hartid, (unsigned long)&secondary_entry, __pa(sp));
44 	assert(ret.error == SBI_SUCCESS);
45 }
46 
47 void smp_boot_secondary(int cpu, void (*func)(void))
48 {
49 	int ret = cpumask_test_and_set_cpu(cpu, &cpu_started);
50 
51 	assert_msg(!ret, "CPU%d already boot once", cpu);
52 	__smp_boot_secondary(cpu, func);
53 
54 	while (!cpu_online(cpu))
55 		smp_wait_for_event();
56 }
57 
58 void smp_boot_secondary_nofail(int cpu, void (*func)(void))
59 {
60 	int ret = cpumask_test_and_set_cpu(cpu, &cpu_started);
61 
62 	if (!ret)
63 		__smp_boot_secondary(cpu, func);
64 
65 	while (!cpu_online(cpu))
66 		smp_wait_for_event();
67 }
68