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Diffstat (limited to 'kernel/arch/powerpc/include/asm/cputhreads.h')
-rw-r--r-- | kernel/arch/powerpc/include/asm/cputhreads.h | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/include/asm/cputhreads.h b/kernel/arch/powerpc/include/asm/cputhreads.h new file mode 100644 index 000000000..5be6c4753 --- /dev/null +++ b/kernel/arch/powerpc/include/asm/cputhreads.h @@ -0,0 +1,97 @@ +#ifndef _ASM_POWERPC_CPUTHREADS_H +#define _ASM_POWERPC_CPUTHREADS_H + +#include <linux/cpumask.h> + +/* + * Mapping of threads to cores + * + * Note: This implementation is limited to a power of 2 number of + * threads per core and the same number for each core in the system + * (though it would work if some processors had less threads as long + * as the CPU numbers are still allocated, just not brought online). + * + * However, the API allows for a different implementation in the future + * if needed, as long as you only use the functions and not the variables + * directly. + */ + +#ifdef CONFIG_SMP +extern int threads_per_core; +extern int threads_per_subcore; +extern int threads_shift; +extern cpumask_t threads_core_mask; +#else +#define threads_per_core 1 +#define threads_per_subcore 1 +#define threads_shift 0 +#define threads_core_mask (*get_cpu_mask(0)) +#endif + +/* cpu_thread_mask_to_cores - Return a cpumask of one per cores + * hit by the argument + * + * @threads: a cpumask of threads + * + * This function returns a cpumask which will have one "cpu" (or thread) + * bit set for each core that has at least one thread set in the argument. + * + * This can typically be used for things like IPI for tlb invalidations + * since those need to be done only once per core/TLB + */ +static inline cpumask_t cpu_thread_mask_to_cores(const struct cpumask *threads) +{ + cpumask_t tmp, res; + int i; + + cpumask_clear(&res); + for (i = 0; i < NR_CPUS; i += threads_per_core) { + cpumask_shift_left(&tmp, &threads_core_mask, i); + if (cpumask_intersects(threads, &tmp)) + cpumask_set_cpu(i, &res); + } + return res; +} + +static inline int cpu_nr_cores(void) +{ + return nr_cpu_ids >> threads_shift; +} + +static inline cpumask_t cpu_online_cores_map(void) +{ + return cpu_thread_mask_to_cores(cpu_online_mask); +} + +#ifdef CONFIG_SMP +int cpu_core_index_of_thread(int cpu); +int cpu_first_thread_of_core(int core); +#else +static inline int cpu_core_index_of_thread(int cpu) { return cpu; } +static inline int cpu_first_thread_of_core(int core) { return core; } +#endif + +static inline int cpu_thread_in_core(int cpu) +{ + return cpu & (threads_per_core - 1); +} + +static inline int cpu_thread_in_subcore(int cpu) +{ + return cpu & (threads_per_subcore - 1); +} + +static inline int cpu_first_thread_sibling(int cpu) +{ + return cpu & ~(threads_per_core - 1); +} + +static inline int cpu_last_thread_sibling(int cpu) +{ + return cpu | (threads_per_core - 1); +} + + + +#endif /* _ASM_POWERPC_CPUTHREADS_H */ + |