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_shift;
22 extern cpumask_t threads_core_mask;
23 #else
24 #define threads_per_core	1
25 #define threads_shift		0
26 #define threads_core_mask	(CPU_MASK_CPU0)
27 #endif
28 
29 /* cpu_thread_mask_to_cores - Return a cpumask of one per cores
30  *                            hit by the argument
31  *
32  * @threads:	a cpumask of threads
33  *
34  * This function returns a cpumask which will have one "cpu" (or thread)
35  * bit set for each core that has at least one thread set in the argument.
36  *
37  * This can typically be used for things like IPI for tlb invalidations
38  * since those need to be done only once per core/TLB
39  */
40 static inline cpumask_t cpu_thread_mask_to_cores(const struct cpumask *threads)
41 {
42 	cpumask_t	tmp, res;
43 	int		i;
44 
45 	cpumask_clear(&res);
46 	for (i = 0; i < NR_CPUS; i += threads_per_core) {
47 		cpumask_shift_left(&tmp, &threads_core_mask, i);
48 		if (cpumask_intersects(threads, &tmp))
49 			cpumask_set_cpu(i, &res);
50 	}
51 	return res;
52 }
53 
54 static inline int cpu_nr_cores(void)
55 {
56 	return NR_CPUS >> threads_shift;
57 }
58 
59 static inline cpumask_t cpu_online_cores_map(void)
60 {
61 	return cpu_thread_mask_to_cores(cpu_online_mask);
62 }
63 
64 #ifdef CONFIG_SMP
65 int cpu_core_index_of_thread(int cpu);
66 int cpu_first_thread_of_core(int core);
67 #else
68 static inline int cpu_core_index_of_thread(int cpu) { return cpu; }
69 static inline int cpu_first_thread_of_core(int core) { return core; }
70 #endif
71 
72 static inline int cpu_thread_in_core(int cpu)
73 {
74 	return cpu & (threads_per_core - 1);
75 }
76 
77 static inline int cpu_first_thread_sibling(int cpu)
78 {
79 	return cpu & ~(threads_per_core - 1);
80 }
81 
82 static inline int cpu_last_thread_sibling(int cpu)
83 {
84 	return cpu | (threads_per_core - 1);
85 }
86 
87 
88 
89 #endif /* _ASM_POWERPC_CPUTHREADS_H */
90 
91