mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-27 22:53:55 +08:00
5853aef1ac
On POWER8 we have a new concept of a subcore. This is what happens when you take a regular core and split it. A subcore is a grouping of two or four SMT threads, as well as a handfull of SPRs which allows the subcore to appear as if it were a core from the point of view of a guest. Unlike threads_per_core which is fixed at boot, threads_per_subcore can change while the system is running. Most code will not want to use threads_per_subcore. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
98 lines
2.4 KiB
C
98 lines
2.4 KiB
C
#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 (CPU_MASK_CPU0)
|
|
#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_CPUS >> 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 */
|
|
|