xref: /openbmc/linux/arch/arm/include/asm/smp_plat.h (revision da1d9caf)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * ARM specific SMP header, this contains our implementation
4  * details.
5  */
6 #ifndef __ASMARM_SMP_PLAT_H
7 #define __ASMARM_SMP_PLAT_H
8 
9 #include <linux/cpumask.h>
10 #include <linux/err.h>
11 
12 #include <asm/cpu.h>
13 #include <asm/cputype.h>
14 
15 /*
16  * Return true if we are running on a SMP platform
17  */
18 static inline bool is_smp(void)
19 {
20 #ifndef CONFIG_SMP
21 	return false;
22 #elif defined(CONFIG_SMP_ON_UP)
23 	extern unsigned int smp_on_up;
24 	return !!smp_on_up;
25 #else
26 	return true;
27 #endif
28 }
29 
30 /**
31  * smp_cpuid_part() - return part id for a given cpu
32  * @cpu:	logical cpu id.
33  *
34  * Return: part id of logical cpu passed as argument.
35  */
36 static inline unsigned int smp_cpuid_part(int cpu)
37 {
38 	struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpu);
39 
40 	return is_smp() ? cpu_info->cpuid & ARM_CPU_PART_MASK :
41 			  read_cpuid_part();
42 }
43 
44 /* all SMP configurations have the extended CPUID registers */
45 #ifndef CONFIG_MMU
46 #define tlb_ops_need_broadcast()	0
47 #else
48 static inline int tlb_ops_need_broadcast(void)
49 {
50 	if (!is_smp())
51 		return 0;
52 
53 	return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 2;
54 }
55 #endif
56 
57 #if !defined(CONFIG_SMP) || __LINUX_ARM_ARCH__ >= 7
58 #define cache_ops_need_broadcast()	0
59 #else
60 static inline int cache_ops_need_broadcast(void)
61 {
62 	if (!is_smp())
63 		return 0;
64 
65 	return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 1;
66 }
67 #endif
68 
69 /*
70  * Logical CPU mapping.
71  */
72 extern u32 __cpu_logical_map[];
73 #define cpu_logical_map(cpu)	__cpu_logical_map[cpu]
74 /*
75  * Retrieve logical cpu index corresponding to a given MPIDR[23:0]
76  *  - mpidr: MPIDR[23:0] to be used for the look-up
77  *
78  * Returns the cpu logical index or -EINVAL on look-up error
79  */
80 static inline int get_logical_index(u32 mpidr)
81 {
82 	int cpu;
83 	for (cpu = 0; cpu < nr_cpu_ids; cpu++)
84 		if (cpu_logical_map(cpu) == mpidr)
85 			return cpu;
86 	return -EINVAL;
87 }
88 
89 /*
90  * NOTE ! Assembly code relies on the following
91  * structure memory layout in order to carry out load
92  * multiple from its base address. For more
93  * information check arch/arm/kernel/sleep.S
94  */
95 struct mpidr_hash {
96 	u32	mask; /* used by sleep.S */
97 	u32	shift_aff[3]; /* used by sleep.S */
98 	u32	bits;
99 };
100 
101 extern struct mpidr_hash mpidr_hash;
102 
103 static inline u32 mpidr_hash_size(void)
104 {
105 	return 1 << mpidr_hash.bits;
106 }
107 
108 extern int platform_can_secondary_boot(void);
109 extern int platform_can_cpu_hotplug(void);
110 
111 #ifdef CONFIG_HOTPLUG_CPU
112 extern int platform_can_hotplug_cpu(unsigned int cpu);
113 #else
114 static inline int platform_can_hotplug_cpu(unsigned int cpu)
115 {
116 	return 0;
117 }
118 #endif
119 
120 #endif
121