xref: /openbmc/linux/arch/arm/include/asm/smp_plat.h (revision b96fc2f3)
1 /*
2  * ARM specific SMP header, this contains our implementation
3  * details.
4  */
5 #ifndef __ASMARM_SMP_PLAT_H
6 #define __ASMARM_SMP_PLAT_H
7 
8 #include <linux/cpumask.h>
9 #include <linux/err.h>
10 
11 #include <asm/cpu.h>
12 #include <asm/cputype.h>
13 
14 /*
15  * Return true if we are running on a SMP platform
16  */
17 static inline bool is_smp(void)
18 {
19 #ifndef CONFIG_SMP
20 	return false;
21 #elif defined(CONFIG_SMP_ON_UP)
22 	extern unsigned int smp_on_up;
23 	return !!smp_on_up;
24 #else
25 	return true;
26 #endif
27 }
28 
29 /**
30  * smp_cpuid_part() - return part id for a given cpu
31  * @cpu:	logical cpu id.
32  *
33  * Return: part id of logical cpu passed as argument.
34  */
35 static inline unsigned int smp_cpuid_part(int cpu)
36 {
37 	struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpu);
38 
39 	return is_smp() ? cpu_info->cpuid & ARM_CPU_PART_MASK :
40 			  read_cpuid_part();
41 }
42 
43 /* all SMP configurations have the extended CPUID registers */
44 #ifndef CONFIG_MMU
45 #define tlb_ops_need_broadcast()	0
46 #else
47 static inline int tlb_ops_need_broadcast(void)
48 {
49 	if (!is_smp())
50 		return 0;
51 
52 	return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 2;
53 }
54 #endif
55 
56 #if !defined(CONFIG_SMP) || __LINUX_ARM_ARCH__ >= 7
57 #define cache_ops_need_broadcast()	0
58 #else
59 static inline int cache_ops_need_broadcast(void)
60 {
61 	if (!is_smp())
62 		return 0;
63 
64 	return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 1;
65 }
66 #endif
67 
68 /*
69  * Logical CPU mapping.
70  */
71 extern u32 __cpu_logical_map[];
72 #define cpu_logical_map(cpu)	__cpu_logical_map[cpu]
73 /*
74  * Retrieve logical cpu index corresponding to a given MPIDR[23:0]
75  *  - mpidr: MPIDR[23:0] to be used for the look-up
76  *
77  * Returns the cpu logical index or -EINVAL on look-up error
78  */
79 static inline int get_logical_index(u32 mpidr)
80 {
81 	int cpu;
82 	for (cpu = 0; cpu < nr_cpu_ids; cpu++)
83 		if (cpu_logical_map(cpu) == mpidr)
84 			return cpu;
85 	return -EINVAL;
86 }
87 
88 /*
89  * NOTE ! Assembly code relies on the following
90  * structure memory layout in order to carry out load
91  * multiple from its base address. For more
92  * information check arch/arm/kernel/sleep.S
93  */
94 struct mpidr_hash {
95 	u32	mask; /* used by sleep.S */
96 	u32	shift_aff[3]; /* used by sleep.S */
97 	u32	bits;
98 };
99 
100 extern struct mpidr_hash mpidr_hash;
101 
102 static inline u32 mpidr_hash_size(void)
103 {
104 	return 1 << mpidr_hash.bits;
105 }
106 
107 extern int platform_can_secondary_boot(void);
108 extern int platform_can_cpu_hotplug(void);
109 
110 #ifdef CONFIG_HOTPLUG_CPU
111 extern int platform_can_hotplug_cpu(unsigned int cpu);
112 #else
113 static inline int platform_can_hotplug_cpu(unsigned int cpu)
114 {
115 	return 0;
116 }
117 #endif
118 
119 #endif
120