1 /*
2 * Secondary cpu support
3 *
4 * Copyright (C) 2015, Red Hat Inc, Andrew Jones <drjones@redhat.com>
5 *
6 * This work is licensed under the terms of the GNU LGPL, version 2.
7 */
8 #include <libcflat.h>
9 #include <auxinfo.h>
10 #include <cpumask.h>
11 #include <asm/thread_info.h>
12 #include <asm/spinlock.h>
13 #include <asm/mmu.h>
14 #include <asm/psci.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 struct secondary_data secondary_data;
22 static struct spinlock lock;
23
24 /* Needed to compile with -Wmissing-prototypes */
25 secondary_entry_fn secondary_cinit(void);
26
secondary_cinit(void)27 secondary_entry_fn secondary_cinit(void)
28 {
29 struct thread_info *ti = current_thread_info();
30 secondary_entry_fn entry;
31
32 thread_info_init(ti, 0);
33
34 if (!(auxinfo.flags & AUXINFO_MMU_OFF)) {
35 ti->pgtable = mmu_idmap;
36 mmu_mark_enabled(ti->cpu);
37 }
38
39 /*
40 * Save secondary_data.entry locally to avoid opening a race
41 * window between marking ourselves online and calling it.
42 */
43 entry = secondary_data.entry;
44 set_cpu_online(ti->cpu, true);
45 smp_send_event();
46
47 /*
48 * Return to the assembly stub, allowing entry to be called
49 * from there with an empty stack.
50 */
51 return entry;
52 }
53
__smp_boot_secondary(int cpu,secondary_entry_fn entry)54 static void __smp_boot_secondary(int cpu, secondary_entry_fn entry)
55 {
56 int ret;
57
58 secondary_data.stack = thread_stack_alloc();
59 secondary_data.entry = entry;
60 mmu_mark_disabled(cpu);
61 ret = cpu_psci_cpu_boot(cpu);
62 assert(ret == 0);
63
64 while (!cpu_online(cpu))
65 smp_wait_for_event();
66 }
67
smp_boot_secondary(int cpu,secondary_entry_fn entry)68 void smp_boot_secondary(int cpu, secondary_entry_fn entry)
69 {
70 spin_lock(&lock);
71 assert_msg(!cpu_online(cpu), "CPU%d already boot once", cpu);
72 __smp_boot_secondary(cpu, entry);
73 spin_unlock(&lock);
74 }
75
smp_boot_secondary_nofail(int cpu,secondary_entry_fn entry)76 void smp_boot_secondary_nofail(int cpu, secondary_entry_fn entry)
77 {
78 spin_lock(&lock);
79 if (!cpu_online(cpu))
80 __smp_boot_secondary(cpu, entry);
81 spin_unlock(&lock);
82 }
83