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 */
37 extern u64 __cpu_logical_map[NR_CPUS];
38 extern u64 cpu_logical_map(unsigned int cpu);
39
40 static inline void set_cpu_logical_map(unsigned int cpu, u64 hwid)
41 {
42 __cpu_logical_map[cpu] = hwid;
43 }
44
45 struct seq_file;
46
47 /*
48 * Discover the set of possible CPUs and determine their
49 * SMP operations.
50 */
51 extern void smp_init_cpus(void);
52
53 /*
54 * Register IPI interrupts with the arch SMP code
55 */
56 extern 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 */
61 asmlinkage 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 */
68 struct secondary_data {
69 struct task_struct *task;
70 long status;
71 };
72
73 extern struct secondary_data secondary_data;
74 extern long __early_cpu_boot_status;
75 extern void secondary_entry(void);
76
77 extern void arch_send_call_function_single_ipi(int cpu);
78 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
79
80 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
81 extern void arch_send_wakeup_ipi(unsigned int cpu);
82 #else
83 static inline void arch_send_wakeup_ipi(unsigned int cpu)
84 {
85 BUILD_BUG();
86 }
87 #endif
88
89 extern int __cpu_disable(void);
90
91 static inline void __cpu_die(unsigned int cpu) { }
92 extern void __noreturn cpu_die(void);
93 extern void __noreturn cpu_die_early(void);
94
95 static inline void __noreturn cpu_park_loop(void)
96 {
97 for (;;) {
98 wfe();
99 wfi();
100 }
101 }
102
103 static 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 */
115 static 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 */
131 bool cpus_are_stuck_in_kernel(void);
132
133 extern void crash_smp_send_stop(void);
134 extern bool smp_crash_stop_failed(void);
135
136 #endif /* ifndef __ASSEMBLY__ */
137
138 #endif /* ifndef __ASM_SMP_H */
139
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