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