osfmk/kperf/arm/kperf_mp.c

   1 /*
   2  * Copyright (c) 2011-2016 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include <arm/cpu_internal.h>
  30 #include <kern/machine.h>
  31 #include <kern/cpu_number.h>
  32 #include <kern/kalloc.h>
  33 #include <kern/processor.h>
  34 #include <kperf/kperf.h>
  35 #include <kperf/kperf_arch.h>
  36 #include <kperf/kperf_timer.h>
  37 #include <mach/mach_types.h>
  38 #include <machine/machine_routines.h> /* xcall */
  39 #include <stdatomic.h>
  40
  41 void
  42 kperf_signal_handler(unsigned int cpu_number)
  43 {
  44         uint64_t cpu_mask = UINT64_C(1) << cpu_number;
  45
  46         /* find all the timers that caused a signal */
  47         for (int i = 0; i < (int)kperf_timerc; i++) {
  48                 uint64_t pending_cpus;
  49                 struct kperf_timer *timer = &kperf_timerv[i];
  50
  51                 pending_cpus = atomic_fetch_and_explicit(&timer->pending_cpus,
  52                     ~cpu_mask, memory_order_relaxed);
  53                 if (pending_cpus & cpu_mask) {
  54                         kperf_ipi_handler(timer);
  55                 }
  56         }
  57 }
  58
  59 bool
  60 kperf_mp_broadcast_other_running(struct kperf_timer *timer)
  61 {
  62         int current_cpu = cpu_number();
  63         bool system_only_self = true;
  64         int n_cpus = machine_info.logical_cpu_max;
  65
  66         /* signal all running processors */
  67         for (int i = 0; i < n_cpus; i++) {
  68                 uint64_t i_bit = UINT64_C(1) << i;
  69                 processor_t processor = cpu_to_processor(i);
  70
  71                 /* do not IPI processors that are not scheduling threads */
  72                 if (processor == PROCESSOR_NULL ||
  73                     processor->state != PROCESSOR_RUNNING ||
  74                     processor->active_thread == THREAD_NULL) {
  75                         continue;
  76                 }
  77
  78                 if (i == current_cpu) {
  79                         system_only_self = false;
  80                         continue;
  81                 }
  82
  83                 /* nor processors that have not responded to the last broadcast */
  84                 uint64_t already_pending = atomic_fetch_or_explicit(
  85                         &timer->pending_cpus, i_bit, memory_order_relaxed);
  86                 if (already_pending & i_bit) {
  87 #if DEVELOPMENT || DEBUG
  88                         atomic_fetch_add_explicit(&kperf_pending_ipis, 1,
  89                             memory_order_relaxed);
  90 #endif /* DEVELOPMENT || DEBUG */
  91                         continue;
  92                 }
  93
  94                 cpu_signal(cpu_datap(i), SIGPkptimer, NULL, NULL);
  95         }
  96
  97         return system_only_self;
  98 }