osfmk/kern/counter_common.c

   1 /* * Copyright (c) 2020 Apple Inc. All rights reserved.
   2  *
   3  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   4  *
   5  * This file contains Original Code and/or Modifications of Original Code
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   7  * Version 2.0 (the 'License'). You may not use this file except in
   8  * compliance with the License. The rights granted to you under the License
   9  * may not be used to create, or enable the creation or redistribution of,
  10  * unlawful or unlicensed copies of an Apple operating system, or to
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  12  * terms of an Apple operating system software license agreement.
  13  *
  14  * Please obtain a copy of the License at
  15  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  16  *
  17  * The Original Code and all software distributed under the License are
  18  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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  22  * Please see the License for the specific language governing rights and
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  26  */
  27
  28 #include <kern/assert.h>
  29 #include <kern/cpu_data.h>
  30 #include <kern/counter.h>
  31 #include <kern/zalloc.h>
  32 #include <machine/atomic.h>
  33 #include <machine/machine_routines.h>
  34 #include <machine/cpu_number.h>
  35
  36 SECURITY_READ_ONLY_LATE(zone_t) counters_zone;
  37 ZONE_INIT(&counters_zone, "per_cpu_counters", sizeof(uint64_t),
  38     ZC_PERCPU | ZC_ALIGNMENT_REQUIRED, ZONE_ID_ANY, NULL);
  39
  40 /*
  41  * Tracks how many static scalable counters are in use since they won't show up
  42  * in the per_cpu_counters zone stats.
  43  */
  44 uint64_t num_static_scalable_counters;
  45
  46 /*
  47  * Mangle the given scalable_counter_t so that it points to the early storage
  48  * regardless of which CPU # we're boot on.
  49  * Must be run before we go multi-core.
  50  */
  51 __startup_func void
  52 scalable_counter_static_boot_mangle(scalable_counter_t *counter)
  53 {
  54         *counter = __zpcpu_mangle_for_boot(*counter);
  55 }
  56
  57 /*
  58  * Initializes a static counter in permanent per-cpu memory.
  59  * Run during startup for each static per-cpu counter
  60  * Must be run before we go multi-core.
  61  */
  62 __startup_func void
  63 scalable_counter_static_init(scalable_counter_t *counter)
  64 {
  65         /*
  66          * We pointed the counter to a single global value during early boot.
  67          * Grab that value now. We'll store it in our current CPU's value
  68          */
  69         uint64_t current_value = os_atomic_load_wide(zpercpu_get(*counter), relaxed);
  70         /*
  71          * This counter can't be freed so we allocate it out of the permanent zone rather than
  72          * our counter zone.
  73          */
  74         *counter = zalloc_percpu_permanent(sizeof(uint64_t), ZALIGN_64);
  75         os_atomic_store_wide(zpercpu_get(*counter), current_value, relaxed);
  76         num_static_scalable_counters++;
  77 }
  78
  79 OS_OVERLOADABLE
  80 void
  81 counter_alloc(scalable_counter_t *counter)
  82 {
  83         *counter = zalloc_percpu(counters_zone, Z_WAITOK | Z_ZERO | Z_NOFAIL);
  84 }
  85
  86 OS_OVERLOADABLE
  87 void
  88 counter_alloc(atomic_counter_t *counter)
  89 {
  90         os_atomic_store_wide(counter, 0, relaxed);
  91 }
  92
  93 OS_OVERLOADABLE
  94 void
  95 counter_free(scalable_counter_t *counter)
  96 {
  97         zfree_percpu(counters_zone, *counter);
  98 }
  99
 100 OS_OVERLOADABLE
 101 void
 102 counter_free(atomic_counter_t *counter)
 103 {
 104         (void)counter;
 105 }
 106
 107 OS_OVERLOADABLE
 108 void
 109 counter_add(atomic_counter_t *counter, uint64_t amount)
 110 {
 111         os_atomic_add(counter, amount, relaxed);
 112 }
 113
 114 OS_OVERLOADABLE
 115 void
 116 counter_inc(atomic_counter_t *counter)
 117 {
 118         os_atomic_inc(counter, relaxed);
 119 }
 120
 121 OS_OVERLOADABLE
 122 void
 123 counter_dec(atomic_counter_t *counter)
 124 {
 125         os_atomic_dec(counter, relaxed);
 126 }
 127
 128 OS_OVERLOADABLE
 129 void
 130 counter_add_preemption_disabled(atomic_counter_t *counter, uint64_t amount)
 131 {
 132         counter_add(counter, amount);
 133 }
 134
 135 OS_OVERLOADABLE
 136 void
 137 counter_inc_preemption_disabled(atomic_counter_t *counter)
 138 {
 139         counter_inc(counter);
 140 }
 141
 142 OS_OVERLOADABLE
 143 void
 144 counter_dec_preemption_disabled(atomic_counter_t *counter)
 145 {
 146         counter_dec(counter);
 147 }
 148
 149 OS_OVERLOADABLE
 150 uint64_t
 151 counter_load(atomic_counter_t *counter)
 152 {
 153         return os_atomic_load_wide(counter, relaxed);
 154 }
 155
 156 OS_OVERLOADABLE
 157 uint64_t
 158 counter_load(scalable_counter_t *counter)
 159 {
 160         uint64_t value = 0;
 161         zpercpu_foreach(it, *counter) {
 162                 value += os_atomic_load_wide(it, relaxed);
 163         }
 164         return value;
 165 }