linux-stable/arch/powerpc/include/asm/cputhreads.h
Gautham R. Shenoy 425752c63b powerpc: Detect the presence of big-cores via "ibm, thread-groups"
On IBM POWER9, the device tree exposes a property array identifed by
"ibm,thread-groups" which will indicate which groups of threads share
a particular set of resources.

As of today we only have one form of grouping identifying the group of
threads in the core that share the L1 cache, translation cache and
instruction data flow.

This patch adds helper functions to parse the contents of
"ibm,thread-groups" and populate a per-cpu variable to cache
information about siblings of each CPU that share the L1, traslation
cache and instruction data-flow.

It also defines a new global variable named "has_big_cores" which
indicates if the cores on this configuration have multiple groups of
threads that share L1 cache.

For each online CPU, it maintains a cpu_smallcore_mask, which
indicates the online siblings which share the L1-cache with it.

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-13 22:21:25 +11:00

119 lines
2.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_POWERPC_CPUTHREADS_H
#define _ASM_POWERPC_CPUTHREADS_H
#ifndef __ASSEMBLY__
#include <linux/cpumask.h>
#include <asm/cpu_has_feature.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 bool has_big_cores;
extern cpumask_t threads_core_mask;
#else
#define threads_per_core 1
#define threads_per_subcore 1
#define threads_shift 0
#define has_big_cores 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 online threads
*
* This function returns a cpumask which will have one online cpu's
* 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, cpu;
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)) {
cpu = cpumask_next_and(-1, &tmp, cpu_online_mask);
if (cpu < nr_cpu_ids)
cpumask_set_cpu(cpu, &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);
}
static inline u32 get_tensr(void)
{
#ifdef CONFIG_BOOKE
if (cpu_has_feature(CPU_FTR_SMT))
return mfspr(SPRN_TENSR);
#endif
return 1;
}
void book3e_start_thread(int thread, unsigned long addr);
void book3e_stop_thread(int thread);
#endif /* __ASSEMBLY__ */
#define INVALID_THREAD_HWID 0x0fff
#endif /* _ASM_POWERPC_CPUTHREADS_H */