xref: /openbmc/linux/arch/riscv/include/asm/smp.h (revision c4e78957)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 Regents of the University of California
4  */
5 
6 #ifndef _ASM_RISCV_SMP_H
7 #define _ASM_RISCV_SMP_H
8 
9 #include <linux/cpumask.h>
10 #include <linux/irqreturn.h>
11 #include <linux/thread_info.h>
12 
13 #define INVALID_HARTID ULONG_MAX
14 
15 struct seq_file;
16 extern unsigned long boot_cpu_hartid;
17 
18 struct riscv_ipi_ops {
19 	void (*ipi_inject)(const struct cpumask *target);
20 	void (*ipi_clear)(void);
21 };
22 
23 #ifdef CONFIG_SMP
24 /*
25  * Mapping between linux logical cpu index and hartid.
26  */
27 extern unsigned long __cpuid_to_hartid_map[NR_CPUS];
28 #define cpuid_to_hartid_map(cpu)    __cpuid_to_hartid_map[cpu]
29 
30 /* print IPI stats */
31 void show_ipi_stats(struct seq_file *p, int prec);
32 
33 /* SMP initialization hook for setup_arch */
34 void __init setup_smp(void);
35 
36 /* Called from C code, this handles an IPI. */
37 void handle_IPI(struct pt_regs *regs);
38 
39 /* Hook for the generic smp_call_function_many() routine. */
40 void arch_send_call_function_ipi_mask(struct cpumask *mask);
41 
42 /* Hook for the generic smp_call_function_single() routine. */
43 void arch_send_call_function_single_ipi(int cpu);
44 
45 int riscv_hartid_to_cpuid(int hartid);
46 
47 /* Set custom IPI operations */
48 void riscv_set_ipi_ops(const struct riscv_ipi_ops *ops);
49 
50 /* Clear IPI for current CPU */
51 void riscv_clear_ipi(void);
52 
53 /* Secondary hart entry */
54 asmlinkage void smp_callin(void);
55 
56 /*
57  * Obtains the hart ID of the currently executing task.  This relies on
58  * THREAD_INFO_IN_TASK, but we define that unconditionally.
59  */
60 #define raw_smp_processor_id() (current_thread_info()->cpu)
61 
62 #if defined CONFIG_HOTPLUG_CPU
63 int __cpu_disable(void);
64 void __cpu_die(unsigned int cpu);
65 #endif /* CONFIG_HOTPLUG_CPU */
66 
67 #else
68 
69 static inline void show_ipi_stats(struct seq_file *p, int prec)
70 {
71 }
72 
73 static inline int riscv_hartid_to_cpuid(int hartid)
74 {
75 	if (hartid == boot_cpu_hartid)
76 		return 0;
77 
78 	return -1;
79 }
80 static inline unsigned long cpuid_to_hartid_map(int cpu)
81 {
82 	return boot_cpu_hartid;
83 }
84 
85 static inline void riscv_set_ipi_ops(const struct riscv_ipi_ops *ops)
86 {
87 }
88 
89 static inline void riscv_clear_ipi(void)
90 {
91 }
92 
93 #endif /* CONFIG_SMP */
94 
95 #if defined(CONFIG_HOTPLUG_CPU) && (CONFIG_SMP)
96 bool cpu_has_hotplug(unsigned int cpu);
97 #else
98 static inline bool cpu_has_hotplug(unsigned int cpu)
99 {
100 	return false;
101 }
102 #endif
103 
104 #endif /* _ASM_RISCV_SMP_H */
105