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 offline).
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(cpumask_t threads)
41 {
42 	cpumask_t	tmp, res;
43 	int		i;
44 
45 	res = CPU_MASK_NONE;
46 	for (i = 0; i < NR_CPUS; i += threads_per_core) {
47 		cpus_shift_left(tmp, threads_core_mask, i);
48 		if (cpus_intersects(threads, tmp))
49 			cpu_set(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_map);
62 }
63 
64 static inline int cpu_thread_to_core(int cpu)
65 {
66 	return cpu >> threads_shift;
67 }
68 
69 static inline int cpu_thread_in_core(int cpu)
70 {
71 	return cpu & (threads_per_core - 1);
72 }
73 
74 static inline int cpu_first_thread_in_core(int cpu)
75 {
76 	return cpu & ~(threads_per_core - 1);
77 }
78 
79 static inline int cpu_last_thread_in_core(int cpu)
80 {
81 	return cpu | (threads_per_core - 1);
82 }
83 
84 
85 
86 #endif /* _ASM_POWERPC_CPUTHREADS_H */
87 
88