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
set_cpu_logical_map(unsigned int cpu,u64 hwid)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 enum 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 */
73 extern void set_smp_ipi_range_percpu(int ipi_base, int nr_ipi, int ncpus);
74
set_smp_ipi_range(int ipi_base,int n)75 static 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 */
83 asmlinkage 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 */
90 struct secondary_data {
91 struct task_struct *task;
92 long status;
93 };
94
95 extern struct secondary_data secondary_data;
96 extern long __early_cpu_boot_status;
97 extern void secondary_entry(void);
98
99 extern void arch_send_call_function_single_ipi(int cpu);
100 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
101
102 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
103 extern void arch_send_wakeup_ipi(unsigned int cpu);
104 #else
arch_send_wakeup_ipi(unsigned int cpu)105 static inline void arch_send_wakeup_ipi(unsigned int cpu)
106 {
107 BUILD_BUG();
108 }
109 #endif
110
111 extern int __cpu_disable(void);
112
__cpu_die(unsigned int cpu)113 static inline void __cpu_die(unsigned int cpu) { }
114 extern void __noreturn cpu_die(void);
115 extern void __noreturn cpu_die_early(void);
116
cpu_park_loop(void)117 static inline void __noreturn cpu_park_loop(void)
118 {
119 for (;;) {
120 wfe();
121 wfi();
122 }
123 }
124
update_cpu_boot_status(int val)125 static 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 */
cpu_panic_kernel(void)137 static 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 */
153 bool cpus_are_stuck_in_kernel(void);
154
155 extern void crash_smp_send_stop(void);
156 extern bool smp_crash_stop_failed(void);
157
158 #endif /* ifndef __ASSEMBLY__ */
159
160 #endif /* ifndef __ASM_SMP_H */
161