1 #ifndef _ASM_POWERPC_CPUTHREADS_H
2 #define _ASM_POWERPC_CPUTHREADS_H
3 
4 #include <linux/cpumask.h>
5 
6 /*
7  * Mapping of threads to cores
8  *
9  * Note: This implementation is limited to a power of 2 number of
10  * threads per core and the same number for each core in the system
11  * (though it would work if some processors had less threads as long
12  * as the CPU numbers are still allocated, just not brought online).
13  *
14  * However, the API allows for a different implementation in the future
15  * if needed, as long as you only use the functions and not the variables
16  * directly.
17  */
18 
19 #ifdef CONFIG_SMP
20 extern int threads_per_core;
21 extern int threads_per_subcore;
22 extern int threads_shift;
23 extern cpumask_t threads_core_mask;
24 #else
25 #define threads_per_core	1
26 #define threads_per_subcore	1
27 #define threads_shift		0
28 #define threads_core_mask	(*get_cpu_mask(0))
29 #endif
30 
31 /* cpu_thread_mask_to_cores - Return a cpumask of one per cores
32  *                            hit by the argument
33  *
34  * @threads:	a cpumask of threads
35  *
36  * This function returns a cpumask which will have one "cpu" (or thread)
37  * bit set for each core that has at least one thread set in the argument.
38  *
39  * This can typically be used for things like IPI for tlb invalidations
40  * since those need to be done only once per core/TLB
41  */
42 static inline cpumask_t cpu_thread_mask_to_cores(const struct cpumask *threads)
43 {
44 	cpumask_t	tmp, res;
45 	int		i;
46 
47 	cpumask_clear(&res);
48 	for (i = 0; i < NR_CPUS; i += threads_per_core) {
49 		cpumask_shift_left(&tmp, &threads_core_mask, i);
50 		if (cpumask_intersects(threads, &tmp))
51 			cpumask_set_cpu(i, &res);
52 	}
53 	return res;
54 }
55 
56 static inline int cpu_nr_cores(void)
57 {
58 	return nr_cpu_ids >> threads_shift;
59 }
60 
61 static inline cpumask_t cpu_online_cores_map(void)
62 {
63 	return cpu_thread_mask_to_cores(cpu_online_mask);
64 }
65 
66 #ifdef CONFIG_SMP
67 int cpu_core_index_of_thread(int cpu);
68 int cpu_first_thread_of_core(int core);
69 #else
70 static inline int cpu_core_index_of_thread(int cpu) { return cpu; }
71 static inline int cpu_first_thread_of_core(int core) { return core; }
72 #endif
73 
74 static inline int cpu_thread_in_core(int cpu)
75 {
76 	return cpu & (threads_per_core - 1);
77 }
78 
79 static inline int cpu_thread_in_subcore(int cpu)
80 {
81 	return cpu & (threads_per_subcore - 1);
82 }
83 
84 static inline int cpu_first_thread_sibling(int cpu)
85 {
86 	return cpu & ~(threads_per_core - 1);
87 }
88 
89 static inline int cpu_last_thread_sibling(int cpu)
90 {
91 	return cpu | (threads_per_core - 1);
92 }
93 
94 
95 
96 #endif /* _ASM_POWERPC_CPUTHREADS_H */
97 
98