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Linux kernel mirror (for testing)
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1/*
2 * Copyright (C) 2012 ARM Ltd.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16#ifndef __ASM_SMP_H
17#define __ASM_SMP_H
18
19/* Values for secondary_data.status */
20
21#define CPU_MMU_OFF (-1)
22#define CPU_BOOT_SUCCESS (0)
23/* The cpu invoked ops->cpu_die, synchronise it with cpu_kill */
24#define CPU_KILL_ME (1)
25/* The cpu couldn't die gracefully and is looping in the kernel */
26#define CPU_STUCK_IN_KERNEL (2)
27/* Fatal system error detected by secondary CPU, crash the system */
28#define CPU_PANIC_KERNEL (3)
29
30#ifndef __ASSEMBLY__
31
32#include <linux/threads.h>
33#include <linux/cpumask.h>
34#include <linux/thread_info.h>
35
36#define raw_smp_processor_id() (current_thread_info()->cpu)
37
38struct seq_file;
39
40/*
41 * generate IPI list text
42 */
43extern void show_ipi_list(struct seq_file *p, int prec);
44
45/*
46 * Called from C code, this handles an IPI.
47 */
48extern void handle_IPI(int ipinr, struct pt_regs *regs);
49
50/*
51 * Discover the set of possible CPUs and determine their
52 * SMP operations.
53 */
54extern void smp_init_cpus(void);
55
56/*
57 * Provide a function to raise an IPI cross call on CPUs in callmap.
58 */
59extern void set_smp_cross_call(void (*)(const struct cpumask *, unsigned int));
60
61extern void (*__smp_cross_call)(const struct cpumask *, unsigned int);
62
63/*
64 * Called from the secondary holding pen, this is the secondary CPU entry point.
65 */
66asmlinkage void secondary_start_kernel(void);
67
68/*
69 * Initial data for bringing up a secondary CPU.
70 * @stack - sp for the secondary CPU
71 * @status - Result passed back from the secondary CPU to
72 * indicate failure.
73 */
74struct secondary_data {
75 void *stack;
76 long status;
77};
78
79extern struct secondary_data secondary_data;
80extern long __early_cpu_boot_status;
81extern void secondary_entry(void);
82
83extern void arch_send_call_function_single_ipi(int cpu);
84extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
85
86#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
87extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask);
88#else
89static inline void arch_send_wakeup_ipi_mask(const struct cpumask *mask)
90{
91 BUILD_BUG();
92}
93#endif
94
95extern int __cpu_disable(void);
96
97extern void __cpu_die(unsigned int cpu);
98extern void cpu_die(void);
99extern void cpu_die_early(void);
100
101static inline void cpu_park_loop(void)
102{
103 for (;;) {
104 wfe();
105 wfi();
106 }
107}
108
109static inline void update_cpu_boot_status(int val)
110{
111 WRITE_ONCE(secondary_data.status, val);
112 /* Ensure the visibility of the status update */
113 dsb(ishst);
114}
115
116/*
117 * The calling secondary CPU has detected serious configuration mismatch,
118 * which calls for a kernel panic. Update the boot status and park the calling
119 * CPU.
120 */
121static inline void cpu_panic_kernel(void)
122{
123 update_cpu_boot_status(CPU_PANIC_KERNEL);
124 cpu_park_loop();
125}
126
127/*
128 * If a secondary CPU enters the kernel but fails to come online,
129 * (e.g. due to mismatched features), and cannot exit the kernel,
130 * we increment cpus_stuck_in_kernel and leave the CPU in a
131 * quiesecent loop within the kernel text. The memory containing
132 * this loop must not be re-used for anything else as the 'stuck'
133 * core is executing it.
134 *
135 * This function is used to inhibit features like kexec and hibernate.
136 */
137bool cpus_are_stuck_in_kernel(void);
138
139#endif /* ifndef __ASSEMBLY__ */
140
141#endif /* ifndef __ASM_SMP_H */