xref: /linux/arch/riscv/include/asm/smp.h (revision 0d3b051adbb72ed81956447d0d1e54d5943ee6f5)
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 void riscv_cpuid_to_hartid_mask(const struct cpumask *in, struct cpumask *out);
47 
48 /* Set custom IPI operations */
49 void riscv_set_ipi_ops(struct riscv_ipi_ops *ops);
50 
51 /* Clear IPI for current CPU */
52 void riscv_clear_ipi(void);
53 
54 /* Secondary hart entry */
55 asmlinkage void smp_callin(void);
56 
57 /*
58  * Obtains the hart ID of the currently executing task.  This relies on
59  * THREAD_INFO_IN_TASK, but we define that unconditionally.
60  */
61 #define raw_smp_processor_id() (current_thread_info()->cpu)
62 
63 #if defined CONFIG_HOTPLUG_CPU
64 int __cpu_disable(void);
65 void __cpu_die(unsigned int cpu);
66 void cpu_stop(void);
67 #else
68 #endif /* CONFIG_HOTPLUG_CPU */
69 
70 #else
71 
72 static inline void show_ipi_stats(struct seq_file *p, int prec)
73 {
74 }
75 
76 static inline int riscv_hartid_to_cpuid(int hartid)
77 {
78 	if (hartid == boot_cpu_hartid)
79 		return 0;
80 
81 	return -1;
82 }
83 static inline unsigned long cpuid_to_hartid_map(int cpu)
84 {
85 	return boot_cpu_hartid;
86 }
87 
88 static inline void riscv_cpuid_to_hartid_mask(const struct cpumask *in,
89 					      struct cpumask *out)
90 {
91 	cpumask_clear(out);
92 	cpumask_set_cpu(boot_cpu_hartid, out);
93 }
94 
95 static inline void riscv_set_ipi_ops(struct riscv_ipi_ops *ops)
96 {
97 }
98 
99 static inline void riscv_clear_ipi(void)
100 {
101 }
102 
103 #endif /* CONFIG_SMP */
104 
105 #if defined(CONFIG_HOTPLUG_CPU) && (CONFIG_SMP)
106 bool cpu_has_hotplug(unsigned int cpu);
107 #else
108 static inline bool cpu_has_hotplug(unsigned int cpu)
109 {
110 	return false;
111 }
112 #endif
113 
114 #endif /* _ASM_RISCV_SMP_H */
115