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mbed library sources. With a patch for the can_api

Fork of mbed-dev by mbed official

platform/mbed_critical.c@151:91825d030f9b, 2016-11-14 (annotated)

Committer:
DangerousElectrician
Date:
Mon Nov 14 04:39:23 2016 +0000
Revision:
151:91825d030f9b
Parent:
149:156823d33999 
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Who changed what in which revision?

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<> 149:156823d33999 1 /*
<> 149:156823d33999 2 * Copyright (c) 2015-2016, ARM Limited, All Rights Reserved
<> 149:156823d33999 3 * SPDX-License-Identifier: Apache-2.0
<> 149:156823d33999 4 *
<> 149:156823d33999 5 * Licensed under the Apache License, Version 2.0 (the "License"); you may
<> 149:156823d33999 6 * not use this file except in compliance with the License.
<> 149:156823d33999 7 * You may obtain a copy of the License at
<> 149:156823d33999 8 *
<> 149:156823d33999 9 * http://www.apache.org/licenses/LICENSE-2.0
<> 149:156823d33999 10 *
<> 149:156823d33999 11 * Unless required by applicable law or agreed to in writing, software
<> 149:156823d33999 12 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
<> 149:156823d33999 13 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 149:156823d33999 14 * See the License for the specific language governing permissions and
<> 149:156823d33999 15 * limitations under the License.
<> 149:156823d33999 16 */
<> 149:156823d33999 17
<> 149:156823d33999 18 #include "platform/critical.h"
<> 149:156823d33999 19
<> 149:156823d33999 20 #include "cmsis.h"
<> 149:156823d33999 21 #include "platform/mbed_assert.h"
<> 149:156823d33999 22 #include "platform/toolchain.h"
<> 149:156823d33999 23
<> 149:156823d33999 24 #define EXCLUSIVE_ACCESS (!defined (__CORTEX_M0) && !defined (__CORTEX_M0PLUS))
<> 149:156823d33999 25
<> 149:156823d33999 26 static volatile uint32_t interrupt_enable_counter = 0;
<> 149:156823d33999 27 static volatile bool critical_interrupts_disabled = false;
<> 149:156823d33999 28
<> 149:156823d33999 29 bool core_util_are_interrupts_enabled(void)
<> 149:156823d33999 30 {
<> 149:156823d33999 31 #if defined(__CORTEX_A9)
<> 149:156823d33999 32 return ((__get_CPSR() & 0x80) == 0);
<> 149:156823d33999 33 #else
<> 149:156823d33999 34 return ((__get_PRIMASK() & 0x1) == 0);
<> 149:156823d33999 35 #endif
<> 149:156823d33999 36 }
<> 149:156823d33999 37
<> 149:156823d33999 38 MBED_WEAK void core_util_critical_section_enter(void)
<> 149:156823d33999 39 {
<> 149:156823d33999 40 bool interrupts_disabled = !core_util_are_interrupts_enabled();
<> 149:156823d33999 41 __disable_irq();
<> 149:156823d33999 42
<> 149:156823d33999 43 /* Save the interrupt disabled state as it was prior to any nested critical section lock use */
<> 149:156823d33999 44 if (!interrupt_enable_counter) {
<> 149:156823d33999 45 critical_interrupts_disabled = interrupts_disabled;
<> 149:156823d33999 46 }
<> 149:156823d33999 47
<> 149:156823d33999 48 /* If the interrupt_enable_counter overflows or we are in a nested critical section and interrupts
<> 149:156823d33999 49 are enabled, then something has gone badly wrong thus assert an error.
<> 149:156823d33999 50 */
<> 149:156823d33999 51 MBED_ASSERT(interrupt_enable_counter < UINT32_MAX);
<> 149:156823d33999 52 // FIXME
<> 149:156823d33999 53 #ifndef FEATURE_UVISOR
<> 149:156823d33999 54 if (interrupt_enable_counter > 0) {
<> 149:156823d33999 55 MBED_ASSERT(interrupts_disabled);
<> 149:156823d33999 56 }
<> 149:156823d33999 57 #else
<> 149:156823d33999 58 #warning "core_util_critical_section_enter needs fixing to work from unprivileged code"
<> 149:156823d33999 59 #endif /* FEATURE_UVISOR */
<> 149:156823d33999 60 interrupt_enable_counter++;
<> 149:156823d33999 61 }
<> 149:156823d33999 62
<> 149:156823d33999 63 MBED_WEAK void core_util_critical_section_exit(void)
<> 149:156823d33999 64 {
<> 149:156823d33999 65 /* If critical_section_enter has not previously been called, do nothing */
<> 149:156823d33999 66 if (interrupt_enable_counter) {
<> 149:156823d33999 67
<> 149:156823d33999 68 // FIXME
<> 149:156823d33999 69 #ifndef FEATURE_UVISOR
<> 149:156823d33999 70 bool interrupts_disabled = !core_util_are_interrupts_enabled(); /* get the current interrupt disabled state */
<> 149:156823d33999 71
<> 149:156823d33999 72 MBED_ASSERT(interrupts_disabled); /* Interrupts must be disabled on invoking an exit from a critical section */
<> 149:156823d33999 73 #else
<> 149:156823d33999 74 #warning "core_util_critical_section_exit needs fixing to work from unprivileged code"
<> 149:156823d33999 75 #endif /* FEATURE_UVISOR */
<> 149:156823d33999 76
<> 149:156823d33999 77 interrupt_enable_counter--;
<> 149:156823d33999 78
<> 149:156823d33999 79 /* Only re-enable interrupts if we are exiting the last of the nested critical sections and
<> 149:156823d33999 80 interrupts were enabled on entry to the first critical section.
<> 149:156823d33999 81 */
<> 149:156823d33999 82 if (!interrupt_enable_counter && !critical_interrupts_disabled) {
<> 149:156823d33999 83 __enable_irq();
<> 149:156823d33999 84 }
<> 149:156823d33999 85 }
<> 149:156823d33999 86 }
<> 149:156823d33999 87
<> 149:156823d33999 88 #if EXCLUSIVE_ACCESS
<> 149:156823d33999 89
<> 149:156823d33999 90 /* Supress __ldrex and __strex deprecated warnings - "#3731-D: intrinsic is deprecated" */
<> 149:156823d33999 91 #if defined (__CC_ARM)
<> 149:156823d33999 92 #pragma diag_suppress 3731
<> 149:156823d33999 93 #endif
<> 149:156823d33999 94
<> 149:156823d33999 95 bool core_util_atomic_cas_u8(uint8_t *ptr, uint8_t *expectedCurrentValue, uint8_t desiredValue)
<> 149:156823d33999 96 {
<> 149:156823d33999 97 uint8_t currentValue = __LDREXB((volatile uint8_t*)ptr);
<> 149:156823d33999 98 if (currentValue != *expectedCurrentValue) {
<> 149:156823d33999 99 *expectedCurrentValue = currentValue;
<> 149:156823d33999 100 __CLREX();
<> 149:156823d33999 101 return false;
<> 149:156823d33999 102 }
<> 149:156823d33999 103
<> 149:156823d33999 104 return !__STREXB(desiredValue, (volatile uint8_t*)ptr);
<> 149:156823d33999 105 }
<> 149:156823d33999 106
<> 149:156823d33999 107 bool core_util_atomic_cas_u16(uint16_t *ptr, uint16_t *expectedCurrentValue, uint16_t desiredValue)
<> 149:156823d33999 108 {
<> 149:156823d33999 109 uint16_t currentValue = __LDREXH((volatile uint16_t*)ptr);
<> 149:156823d33999 110 if (currentValue != *expectedCurrentValue) {
<> 149:156823d33999 111 *expectedCurrentValue = currentValue;
<> 149:156823d33999 112 __CLREX();
<> 149:156823d33999 113 return false;
<> 149:156823d33999 114 }
<> 149:156823d33999 115
<> 149:156823d33999 116 return !__STREXH(desiredValue, (volatile uint16_t*)ptr);
<> 149:156823d33999 117 }
<> 149:156823d33999 118
<> 149:156823d33999 119
<> 149:156823d33999 120 bool core_util_atomic_cas_u32(uint32_t *ptr, uint32_t *expectedCurrentValue, uint32_t desiredValue)
<> 149:156823d33999 121 {
<> 149:156823d33999 122 uint32_t currentValue = __LDREXW((volatile uint32_t*)ptr);
<> 149:156823d33999 123 if (currentValue != *expectedCurrentValue) {
<> 149:156823d33999 124 *expectedCurrentValue = currentValue;
<> 149:156823d33999 125 __CLREX();
<> 149:156823d33999 126 return false;
<> 149:156823d33999 127 }
<> 149:156823d33999 128
<> 149:156823d33999 129 return !__STREXW(desiredValue, (volatile uint32_t*)ptr);
<> 149:156823d33999 130 }
<> 149:156823d33999 131
<> 149:156823d33999 132 uint8_t core_util_atomic_incr_u8(uint8_t *valuePtr, uint8_t delta)
<> 149:156823d33999 133 {
<> 149:156823d33999 134 uint8_t newValue;
<> 149:156823d33999 135 do {
<> 149:156823d33999 136 newValue = __LDREXB((volatile uint8_t*)valuePtr) + delta;
<> 149:156823d33999 137 } while (__STREXB(newValue, (volatile uint8_t*)valuePtr));
<> 149:156823d33999 138 return newValue;
<> 149:156823d33999 139 }
<> 149:156823d33999 140
<> 149:156823d33999 141 uint16_t core_util_atomic_incr_u16(uint16_t *valuePtr, uint16_t delta)
<> 149:156823d33999 142 {
<> 149:156823d33999 143 uint16_t newValue;
<> 149:156823d33999 144 do {
<> 149:156823d33999 145 newValue = __LDREXH((volatile uint16_t*)valuePtr) + delta;
<> 149:156823d33999 146 } while (__STREXH(newValue, (volatile uint16_t*)valuePtr));
<> 149:156823d33999 147 return newValue;
<> 149:156823d33999 148 }
<> 149:156823d33999 149
<> 149:156823d33999 150 uint32_t core_util_atomic_incr_u32(uint32_t *valuePtr, uint32_t delta)
<> 149:156823d33999 151 {
<> 149:156823d33999 152 uint32_t newValue;
<> 149:156823d33999 153 do {
<> 149:156823d33999 154 newValue = __LDREXW((volatile uint32_t*)valuePtr) + delta;
<> 149:156823d33999 155 } while (__STREXW(newValue, (volatile uint32_t*)valuePtr));
<> 149:156823d33999 156 return newValue;
<> 149:156823d33999 157 }
<> 149:156823d33999 158
<> 149:156823d33999 159
<> 149:156823d33999 160 uint8_t core_util_atomic_decr_u8(uint8_t *valuePtr, uint8_t delta)
<> 149:156823d33999 161 {
<> 149:156823d33999 162 uint8_t newValue;
<> 149:156823d33999 163 do {
<> 149:156823d33999 164 newValue = __LDREXB((volatile uint8_t*)valuePtr) - delta;
<> 149:156823d33999 165 } while (__STREXB(newValue, (volatile uint8_t*)valuePtr));
<> 149:156823d33999 166 return newValue;
<> 149:156823d33999 167 }
<> 149:156823d33999 168
<> 149:156823d33999 169 uint16_t core_util_atomic_decr_u16(uint16_t *valuePtr, uint16_t delta)
<> 149:156823d33999 170 {
<> 149:156823d33999 171 uint16_t newValue;
<> 149:156823d33999 172 do {
<> 149:156823d33999 173 newValue = __LDREXH((volatile uint16_t*)valuePtr) - delta;
<> 149:156823d33999 174 } while (__STREXH(newValue, (volatile uint16_t*)valuePtr));
<> 149:156823d33999 175 return newValue;
<> 149:156823d33999 176 }
<> 149:156823d33999 177
<> 149:156823d33999 178 uint32_t core_util_atomic_decr_u32(uint32_t *valuePtr, uint32_t delta)
<> 149:156823d33999 179 {
<> 149:156823d33999 180 uint32_t newValue;
<> 149:156823d33999 181 do {
<> 149:156823d33999 182 newValue = __LDREXW((volatile uint32_t*)valuePtr) - delta;
<> 149:156823d33999 183 } while (__STREXW(newValue, (volatile uint32_t*)valuePtr));
<> 149:156823d33999 184 return newValue;
<> 149:156823d33999 185 }
<> 149:156823d33999 186
<> 149:156823d33999 187 #else
<> 149:156823d33999 188
<> 149:156823d33999 189 bool core_util_atomic_cas_u8(uint8_t *ptr, uint8_t *expectedCurrentValue, uint8_t desiredValue)
<> 149:156823d33999 190 {
<> 149:156823d33999 191 bool success;
<> 149:156823d33999 192 uint8_t currentValue;
<> 149:156823d33999 193 core_util_critical_section_enter();
<> 149:156823d33999 194 currentValue = *ptr;
<> 149:156823d33999 195 if (currentValue == *expectedCurrentValue) {
<> 149:156823d33999 196 *ptr = desiredValue;
<> 149:156823d33999 197 success = true;
<> 149:156823d33999 198 } else {
<> 149:156823d33999 199 *expectedCurrentValue = currentValue;
<> 149:156823d33999 200 success = false;
<> 149:156823d33999 201 }
<> 149:156823d33999 202 core_util_critical_section_exit();
<> 149:156823d33999 203 return success;
<> 149:156823d33999 204 }
<> 149:156823d33999 205
<> 149:156823d33999 206 bool core_util_atomic_cas_u16(uint16_t *ptr, uint16_t *expectedCurrentValue, uint16_t desiredValue)
<> 149:156823d33999 207 {
<> 149:156823d33999 208 bool success;
<> 149:156823d33999 209 uint16_t currentValue;
<> 149:156823d33999 210 core_util_critical_section_enter();
<> 149:156823d33999 211 currentValue = *ptr;
<> 149:156823d33999 212 if (currentValue == *expectedCurrentValue) {
<> 149:156823d33999 213 *ptr = desiredValue;
<> 149:156823d33999 214 success = true;
<> 149:156823d33999 215 } else {
<> 149:156823d33999 216 *expectedCurrentValue = currentValue;
<> 149:156823d33999 217 success = false;
<> 149:156823d33999 218 }
<> 149:156823d33999 219 core_util_critical_section_exit();
<> 149:156823d33999 220 return success;
<> 149:156823d33999 221 }
<> 149:156823d33999 222
<> 149:156823d33999 223
<> 149:156823d33999 224 bool core_util_atomic_cas_u32(uint32_t *ptr, uint32_t *expectedCurrentValue, uint32_t desiredValue)
<> 149:156823d33999 225 {
<> 149:156823d33999 226 bool success;
<> 149:156823d33999 227 uint32_t currentValue;
<> 149:156823d33999 228 core_util_critical_section_enter();
<> 149:156823d33999 229 currentValue = *ptr;
<> 149:156823d33999 230 if (currentValue == *expectedCurrentValue) {
<> 149:156823d33999 231 *ptr = desiredValue;
<> 149:156823d33999 232 success = true;
<> 149:156823d33999 233 } else {
<> 149:156823d33999 234 *expectedCurrentValue = currentValue;
<> 149:156823d33999 235 success = false;
<> 149:156823d33999 236 }
<> 149:156823d33999 237 core_util_critical_section_exit();
<> 149:156823d33999 238 return success;
<> 149:156823d33999 239 }
<> 149:156823d33999 240
<> 149:156823d33999 241
<> 149:156823d33999 242 uint8_t core_util_atomic_incr_u8(uint8_t *valuePtr, uint8_t delta)
<> 149:156823d33999 243 {
<> 149:156823d33999 244 uint8_t newValue;
<> 149:156823d33999 245 core_util_critical_section_enter();
<> 149:156823d33999 246 newValue = *valuePtr + delta;
<> 149:156823d33999 247 *valuePtr = newValue;
<> 149:156823d33999 248 core_util_critical_section_exit();
<> 149:156823d33999 249 return newValue;
<> 149:156823d33999 250 }
<> 149:156823d33999 251
<> 149:156823d33999 252 uint16_t core_util_atomic_incr_u16(uint16_t *valuePtr, uint16_t delta)
<> 149:156823d33999 253 {
<> 149:156823d33999 254 uint16_t newValue;
<> 149:156823d33999 255 core_util_critical_section_enter();
<> 149:156823d33999 256 newValue = *valuePtr + delta;
<> 149:156823d33999 257 *valuePtr = newValue;
<> 149:156823d33999 258 core_util_critical_section_exit();
<> 149:156823d33999 259 return newValue;
<> 149:156823d33999 260 }
<> 149:156823d33999 261
<> 149:156823d33999 262 uint32_t core_util_atomic_incr_u32(uint32_t *valuePtr, uint32_t delta)
<> 149:156823d33999 263 {
<> 149:156823d33999 264 uint32_t newValue;
<> 149:156823d33999 265 core_util_critical_section_enter();
<> 149:156823d33999 266 newValue = *valuePtr + delta;
<> 149:156823d33999 267 *valuePtr = newValue;
<> 149:156823d33999 268 core_util_critical_section_exit();
<> 149:156823d33999 269 return newValue;
<> 149:156823d33999 270 }
<> 149:156823d33999 271
<> 149:156823d33999 272
<> 149:156823d33999 273 uint8_t core_util_atomic_decr_u8(uint8_t *valuePtr, uint8_t delta)
<> 149:156823d33999 274 {
<> 149:156823d33999 275 uint8_t newValue;
<> 149:156823d33999 276 core_util_critical_section_enter();
<> 149:156823d33999 277 newValue = *valuePtr - delta;
<> 149:156823d33999 278 *valuePtr = newValue;
<> 149:156823d33999 279 core_util_critical_section_exit();
<> 149:156823d33999 280 return newValue;
<> 149:156823d33999 281 }
<> 149:156823d33999 282
<> 149:156823d33999 283 uint16_t core_util_atomic_decr_u16(uint16_t *valuePtr, uint16_t delta)
<> 149:156823d33999 284 {
<> 149:156823d33999 285 uint16_t newValue;
<> 149:156823d33999 286 core_util_critical_section_enter();
<> 149:156823d33999 287 newValue = *valuePtr - delta;
<> 149:156823d33999 288 *valuePtr = newValue;
<> 149:156823d33999 289 core_util_critical_section_exit();
<> 149:156823d33999 290 return newValue;
<> 149:156823d33999 291 }
<> 149:156823d33999 292
<> 149:156823d33999 293 uint32_t core_util_atomic_decr_u32(uint32_t *valuePtr, uint32_t delta)
<> 149:156823d33999 294 {
<> 149:156823d33999 295 uint32_t newValue;
<> 149:156823d33999 296 core_util_critical_section_enter();
<> 149:156823d33999 297 newValue = *valuePtr - delta;
<> 149:156823d33999 298 *valuePtr = newValue;
<> 149:156823d33999 299 core_util_critical_section_exit();
<> 149:156823d33999 300 return newValue;
<> 149:156823d33999 301 }
<> 149:156823d33999 302
<> 149:156823d33999 303 #endif
<> 149:156823d33999 304
<> 149:156823d33999 305
<> 149:156823d33999 306 bool core_util_atomic_cas_ptr(void **ptr, void **expectedCurrentValue, void *desiredValue) {
<> 149:156823d33999 307 return core_util_atomic_cas_u32(
<> 149:156823d33999 308 (uint32_t *)ptr,
<> 149:156823d33999 309 (uint32_t *)expectedCurrentValue,
<> 149:156823d33999 310 (uint32_t)desiredValue);
<> 149:156823d33999 311 }
<> 149:156823d33999 312
<> 149:156823d33999 313 void *core_util_atomic_incr_ptr(void **valuePtr, ptrdiff_t delta) {
<> 149:156823d33999 314 return (void *)core_util_atomic_incr_u32((uint32_t *)valuePtr, (uint32_t)delta);
<> 149:156823d33999 315 }
<> 149:156823d33999 316
<> 149:156823d33999 317 void *core_util_atomic_decr_ptr(void **valuePtr, ptrdiff_t delta) {
<> 149:156823d33999 318 return (void *)core_util_atomic_decr_u32((uint32_t *)valuePtr, (uint32_t)delta);
<> 149:156823d33999 319 }
<> 149:156823d33999 320