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1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License version 2 as
4 * published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
10 *
11 * Copyright (C) 2012 ARM Limited
12 *
13 * Author: Will Deacon <will.deacon@arm.com>
14 */
15
16#include <linux/init.h>
17#include <linux/smp.h>
18#include <linux/of.h>
19
20#include <asm/psci.h>
21#include <asm/smp_plat.h>
22
23/*
24 * psci_smp assumes that the following is true about PSCI:
25 *
26 * cpu_suspend Suspend the execution on a CPU
27 * @state we don't currently describe affinity levels, so just pass 0.
28 * @entry_point the first instruction to be executed on return
29 * returns 0 success, < 0 on failure
30 *
31 * cpu_off Power down a CPU
32 * @state we don't currently describe affinity levels, so just pass 0.
33 * no return on successful call
34 *
35 * cpu_on Power up a CPU
36 * @cpuid cpuid of target CPU, as from MPIDR
37 * @entry_point the first instruction to be executed on return
38 * returns 0 success, < 0 on failure
39 *
40 * migrate Migrate the context to a different CPU
41 * @cpuid cpuid of target CPU, as from MPIDR
42 * returns 0 success, < 0 on failure
43 *
44 */
45
46extern void secondary_startup(void);
47
48static int psci_boot_secondary(unsigned int cpu, struct task_struct *idle)
49{
50 if (psci_ops.cpu_on)
51 return psci_ops.cpu_on(cpu_logical_map(cpu),
52 __pa(secondary_startup));
53 return -ENODEV;
54}
55
56#ifdef CONFIG_HOTPLUG_CPU
57void __ref psci_cpu_die(unsigned int cpu)
58{
59 const struct psci_power_state ps = {
60 .type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
61 };
62
63 if (psci_ops.cpu_off)
64 psci_ops.cpu_off(ps);
65
66 /* We should never return */
67 panic("psci: cpu %d failed to shutdown\n", cpu);
68}
69#endif
70
71bool __init psci_smp_available(void)
72{
73 /* is cpu_on available at least? */
74 return (psci_ops.cpu_on != NULL);
75}
76
77struct smp_operations __initdata psci_smp_ops = {
78 .smp_boot_secondary = psci_boot_secondary,
79#ifdef CONFIG_HOTPLUG_CPU
80 .cpu_die = psci_cpu_die,
81#endif
82};
1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License version 2 as
4 * published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
10 *
11 * Copyright (C) 2012 ARM Limited
12 *
13 * Author: Will Deacon <will.deacon@arm.com>
14 */
15
16#include <linux/init.h>
17#include <linux/smp.h>
18#include <linux/of.h>
19#include <linux/delay.h>
20#include <linux/psci.h>
21
22#include <uapi/linux/psci.h>
23
24#include <asm/psci.h>
25#include <asm/smp_plat.h>
26
27/*
28 * psci_smp assumes that the following is true about PSCI:
29 *
30 * cpu_suspend Suspend the execution on a CPU
31 * @state we don't currently describe affinity levels, so just pass 0.
32 * @entry_point the first instruction to be executed on return
33 * returns 0 success, < 0 on failure
34 *
35 * cpu_off Power down a CPU
36 * @state we don't currently describe affinity levels, so just pass 0.
37 * no return on successful call
38 *
39 * cpu_on Power up a CPU
40 * @cpuid cpuid of target CPU, as from MPIDR
41 * @entry_point the first instruction to be executed on return
42 * returns 0 success, < 0 on failure
43 *
44 * migrate Migrate the context to a different CPU
45 * @cpuid cpuid of target CPU, as from MPIDR
46 * returns 0 success, < 0 on failure
47 *
48 */
49
50extern void secondary_startup(void);
51
52static int psci_boot_secondary(unsigned int cpu, struct task_struct *idle)
53{
54 if (psci_ops.cpu_on)
55 return psci_ops.cpu_on(cpu_logical_map(cpu),
56 virt_to_idmap(&secondary_startup));
57 return -ENODEV;
58}
59
60#ifdef CONFIG_HOTPLUG_CPU
61int psci_cpu_disable(unsigned int cpu)
62{
63 /* Fail early if we don't have CPU_OFF support */
64 if (!psci_ops.cpu_off)
65 return -EOPNOTSUPP;
66
67 /* Trusted OS will deny CPU_OFF */
68 if (psci_tos_resident_on(cpu))
69 return -EPERM;
70
71 return 0;
72}
73
74void psci_cpu_die(unsigned int cpu)
75{
76 u32 state = PSCI_POWER_STATE_TYPE_POWER_DOWN <<
77 PSCI_0_2_POWER_STATE_TYPE_SHIFT;
78
79 if (psci_ops.cpu_off)
80 psci_ops.cpu_off(state);
81
82 /* We should never return */
83 panic("psci: cpu %d failed to shutdown\n", cpu);
84}
85
86int psci_cpu_kill(unsigned int cpu)
87{
88 int err, i;
89
90 if (!psci_ops.affinity_info)
91 return 1;
92 /*
93 * cpu_kill could race with cpu_die and we can
94 * potentially end up declaring this cpu undead
95 * while it is dying. So, try again a few times.
96 */
97
98 for (i = 0; i < 10; i++) {
99 err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
100 if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) {
101 pr_info("CPU%d killed.\n", cpu);
102 return 1;
103 }
104
105 msleep(10);
106 pr_info("Retrying again to check for CPU kill\n");
107 }
108
109 pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n",
110 cpu, err);
111 /* Make platform_cpu_kill() fail. */
112 return 0;
113}
114
115#endif
116
117bool __init psci_smp_available(void)
118{
119 /* is cpu_on available at least? */
120 return (psci_ops.cpu_on != NULL);
121}
122
123const struct smp_operations psci_smp_ops __initconst = {
124 .smp_boot_secondary = psci_boot_secondary,
125#ifdef CONFIG_HOTPLUG_CPU
126 .cpu_disable = psci_cpu_disable,
127 .cpu_die = psci_cpu_die,
128 .cpu_kill = psci_cpu_kill,
129#endif
130};