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