arch/powerpc/include/asm/cputhreads.h

   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 online threads
  35  *
  36  * This function returns a cpumask which will have one online cpu's
  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, cpu;
  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                         cpu = cpumask_next_and(-1, &tmp, cpu_online_mask);
  52                         if (cpu < nr_cpu_ids)
  53                                 cpumask_set_cpu(cpu, &res);
  54                 }
  55         }
  56         return res;
  57 }
  58
  59 static inline int cpu_nr_cores(void)
  60 {
  61         return nr_cpu_ids >> threads_shift;
  62 }
  63
  64 static inline cpumask_t cpu_online_cores_map(void)
  65 {
  66         return cpu_thread_mask_to_cores(cpu_online_mask);
  67 }
  68
  69 #ifdef CONFIG_SMP
  70 int cpu_core_index_of_thread(int cpu);
  71 int cpu_first_thread_of_core(int core);
  72 #else
  73 static inline int cpu_core_index_of_thread(int cpu) { return cpu; }
  74 static inline int cpu_first_thread_of_core(int core) { return core; }
  75 #endif
  76
  77 static inline int cpu_thread_in_core(int cpu)
  78 {
  79         return cpu & (threads_per_core - 1);
  80 }
  81
  82 static inline int cpu_thread_in_subcore(int cpu)
  83 {
  84         return cpu & (threads_per_subcore - 1);
  85 }
  86
  87 static inline int cpu_first_thread_sibling(int cpu)
  88 {
  89         return cpu & ~(threads_per_core - 1);
  90 }
  91
  92 static inline int cpu_last_thread_sibling(int cpu)
  93 {
  94         return cpu | (threads_per_core - 1);
  95 }
  96
  97
  98
  99 #endif /* _ASM_POWERPC_CPUTHREADS_H */
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