1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_SMP_H
#define __ASM_SMP_H
#include <linux/const.h>
/* Values for secondary_data.status */
#define CPU_STUCK_REASON_SHIFT (8)
#define CPU_BOOT_STATUS_MASK ((UL(1) << CPU_STUCK_REASON_SHIFT) - 1)
#define CPU_MMU_OFF (-1)
#define CPU_BOOT_SUCCESS (0)
/* The cpu invoked ops->cpu_die, synchronise it with cpu_kill */
#define CPU_KILL_ME (1)
/* The cpu couldn't die gracefully and is looping in the kernel */
#define CPU_STUCK_IN_KERNEL (2)
/* Fatal system error detected by secondary CPU, crash the system */
#define CPU_PANIC_KERNEL (3)
#define CPU_STUCK_REASON_52_BIT_VA (UL(1) << CPU_STUCK_REASON_SHIFT)
#define CPU_STUCK_REASON_NO_GRAN (UL(2) << CPU_STUCK_REASON_SHIFT)
#ifndef __ASSEMBLY__
#include <asm/percpu.h>
#include <linux/threads.h>
#include <linux/cpumask.h>
#include <linux/thread_info.h>
DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number);
/*
* We don't use this_cpu_read(cpu_number) as that has implicit writes to
* preempt_count, and associated (compiler) barriers, that we'd like to avoid
* the expense of. If we're preemptible, the value can be stale at use anyway.
* And we can't use this_cpu_ptr() either, as that winds up recursing back
* here under CONFIG_DEBUG_PREEMPT=y.
*/
#define raw_smp_processor_id() (*raw_cpu_ptr(&cpu_number))
/*
* Logical CPU mapping.
*/
extern u64 __cpu_logical_map[NR_CPUS];
extern u64 cpu_logical_map(unsigned int cpu);
static inline void set_cpu_logical_map(unsigned int cpu, u64 hwid)
{
__cpu_logical_map[cpu] = hwid;
}
struct seq_file;
/*
* Discover the set of possible CPUs and determine their
* SMP operations.
*/
extern void smp_init_cpus(void);
/*
* Register IPI interrupts with the arch SMP code
*/
extern void set_smp_ipi_range(int ipi_base, int nr_ipi);
/*
* Called from the secondary holding pen, this is the secondary CPU entry point.
*/
asmlinkage void secondary_start_kernel(void);
/*
* Initial data for bringing up a secondary CPU.
* @status - Result passed back from the secondary CPU to
* indicate failure.
*/
struct secondary_data {
struct task_struct *task;
long status;
};
extern struct secondary_data secondary_data;
extern long __early_cpu_boot_status;
extern void secondary_entry(void);
extern void arch_send_call_function_single_ipi(int cpu);
extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask);
#else
static inline void arch_send_wakeup_ipi_mask(const struct cpumask *mask)
{
BUILD_BUG();
}
#endif
extern int __cpu_disable(void);
extern void __cpu_die(unsigned int cpu);
extern void __noreturn cpu_die(void);
extern void cpu_die_early(void);
static inline void cpu_park_loop(void)
{
for (;;) {
wfe();
wfi();
}
}
static inline void update_cpu_boot_status(int val)
{
WRITE_ONCE(secondary_data.status, val);
/* Ensure the visibility of the status update */
dsb(ishst);
}
/*
* The calling secondary CPU has detected serious configuration mismatch,
* which calls for a kernel panic. Update the boot status and park the calling
* CPU.
*/
static inline void cpu_panic_kernel(void)
{
update_cpu_boot_status(CPU_PANIC_KERNEL);
cpu_park_loop();
}
/*
* If a secondary CPU enters the kernel but fails to come online,
* (e.g. due to mismatched features), and cannot exit the kernel,
* we increment cpus_stuck_in_kernel and leave the CPU in a
* quiesecent loop within the kernel text. The memory containing
* this loop must not be re-used for anything else as the 'stuck'
* core is executing it.
*
* This function is used to inhibit features like kexec and hibernate.
*/
bool cpus_are_stuck_in_kernel(void);
extern void crash_smp_send_stop(void);
extern bool smp_crash_stop_failed(void);
extern void panic_smp_self_stop(void);
#endif /* ifndef __ASSEMBLY__ */
#endif /* ifndef __ASM_SMP_H */
|