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Linux kernel mirror (for testing)
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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 __ASSEMBLER__
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
53enum ipi_msg_type {
54 IPI_RESCHEDULE,
55 IPI_CALL_FUNC,
56 IPI_CPU_STOP,
57 IPI_CPU_STOP_NMI,
58 IPI_TIMER,
59 IPI_IRQ_WORK,
60 NR_IPI,
61 /*
62 * Any enum >= NR_IPI and < MAX_IPI is special and not tracable
63 * with trace_ipi_*
64 */
65 IPI_CPU_BACKTRACE = NR_IPI,
66 IPI_KGDB_ROUNDUP,
67 MAX_IPI
68};
69
70/*
71 * Register IPI interrupts with the arch SMP code
72 */
73extern void set_smp_ipi_range_percpu(int ipi_base, int nr_ipi, int ncpus);
74
75static inline void set_smp_ipi_range(int ipi_base, int n)
76{
77 set_smp_ipi_range_percpu(ipi_base, n, 0);
78}
79
80/*
81 * Called from the secondary holding pen, this is the secondary CPU entry point.
82 */
83asmlinkage void secondary_start_kernel(void);
84
85/*
86 * Initial data for bringing up a secondary CPU.
87 * @status - Result passed back from the secondary CPU to
88 * indicate failure.
89 */
90struct secondary_data {
91 struct task_struct *task;
92 long status;
93};
94
95extern struct secondary_data secondary_data;
96extern long __early_cpu_boot_status;
97extern void secondary_entry(void);
98
99extern void arch_send_call_function_single_ipi(int cpu);
100extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
101
102#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
103extern void arch_send_wakeup_ipi(unsigned int cpu);
104#else
105static inline void arch_send_wakeup_ipi(unsigned int cpu)
106{
107 BUILD_BUG();
108}
109#endif
110
111extern int __cpu_disable(void);
112
113static inline void __cpu_die(unsigned int cpu) { }
114extern void __noreturn cpu_die(void);
115extern void __noreturn cpu_die_early(void);
116
117static inline void __noreturn cpu_park_loop(void)
118{
119 for (;;) {
120 wfe();
121 wfi();
122 }
123}
124
125static inline void update_cpu_boot_status(int val)
126{
127 WRITE_ONCE(secondary_data.status, val);
128 /* Ensure the visibility of the status update */
129 dsb(ishst);
130}
131
132/*
133 * The calling secondary CPU has detected serious configuration mismatch,
134 * which calls for a kernel panic. Update the boot status and park the calling
135 * CPU.
136 */
137static inline void __noreturn cpu_panic_kernel(void)
138{
139 update_cpu_boot_status(CPU_PANIC_KERNEL);
140 cpu_park_loop();
141}
142
143/*
144 * If a secondary CPU enters the kernel but fails to come online,
145 * (e.g. due to mismatched features), and cannot exit the kernel,
146 * we increment cpus_stuck_in_kernel and leave the CPU in a
147 * quiesecent loop within the kernel text. The memory containing
148 * this loop must not be re-used for anything else as the 'stuck'
149 * core is executing it.
150 *
151 * This function is used to inhibit features like kexec and hibernate.
152 */
153bool cpus_are_stuck_in_kernel(void);
154
155extern void crash_smp_send_stop(void);
156extern bool smp_crash_stop_failed(void);
157
158#endif /* ifndef __ASSEMBLER__ */
159
160#endif /* ifndef __ASM_SMP_H */