Diff: simple-mbed-cloud-client/mbed-cloud-client/update-client-hub/modules/atomic-queue/source/critical.c

Revision:

0:8f0bb79ddd48

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/simple-mbed-cloud-client/mbed-cloud-client/update-client-hub/modules/atomic-queue/source/critical.c	Tue May 04 08:55:12 2021 +0000
@@ -0,0 +1,108 @@
+// ----------------------------------------------------------------------------
+// Copyright 2015-2017 ARM Ltd.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ----------------------------------------------------------------------------
+
+// This critical section implementation is generic for mbed OS targets,
+// except Nordic ones
+#if defined(TARGET_LIKE_MBED) && !defined(TARGET_NORDIC)
+
+#include <stdint.h>                  // uint32_t, UINT32_MAX
+#include <stddef.h>                  // NULL
+
+#if defined(YOTTA_CFG_MBED_OS)
+#include "cmsis-core/core_generic.h" //__disable_irq, __enable_irq
+#else
+#include "cmsis.h"
+#endif
+
+#include <assert.h>
+
+// Module include
+#include "aq_critical.h"
+
+static volatile uint32_t interruptEnableCounter = 0;
+static volatile uint32_t critical_primask = 0;
+
+void aq_critical_section_enter()
+{
+    uint32_t primask;
+#if defined(__CORTEX_A9)
+    primask = __get_CPSR(); // get the current interrupt enabled state
+#else
+    primask = __get_PRIMASK(); // get the current interrupt enabled state
+#endif
+    __disable_irq();
+
+    // Save the interrupt enabled state as it was prior to any nested critical section lock use
+    if (!interruptEnableCounter) {
+#if defined(__CORTEX_A9)
+        critical_primask = primask & 0x80;
+#else
+        critical_primask = primask & 0x1;
+#endif
+    }
+#if 0
+    /* If the interruptEnableCounter overflows or we are in a nested critical section and interrupts
+       are enabled, then something has gone badly wrong thus assert an error.
+    */
+
+    /* FIXME: This assertion needs to be commented out for the moment, as it
+     *        triggers a fault when uVisor is enabled. For more information on
+     *        the fault please checkout ARMmbed/mbed-drivers#176. */
+
+    assert(interruptEnableCounter < UINT32_MAX);
+    if (interruptEnableCounter > 0) {
+        assert(primask & 0x1);
+    }
+#endif
+
+    if (interruptEnableCounter < UINT32_MAX) {
+        interruptEnableCounter++;
+    }
+}
+
+void aq_critical_section_exit(void)
+{
+    // If critical_section_enter has not previously been called, do nothing
+    if (interruptEnableCounter) {
+#if 0
+        /* FIXME: This assertion needs to be commented out for the moment, as it
+         *        triggers a fault when uVisor is enabled. For more information
+         *        on the fault please checkout ARMmbed/mbed-drivers#176. */
+
+        uint32_t primask;
+#if defined(__CORTEX_A9)
+        primask = __get_CPSR(); // get the current interrupt enabled state
+#else
+        primask = __get_PRIMASK(); // get the current interrupt enabled state
+#endif
+        assert(primask & 0x1); // Interrupts must be disabled on invoking an exit from a critical section
+#endif
+
+        interruptEnableCounter--;
+
+
+        /* Only re-enable interrupts if we are exiting the last of the nested critical sections and
+           interrupts were enabled on entry to the first critical section.
+        */
+        if (!interruptEnableCounter && !critical_primask) {
+            __enable_irq();
+        }
+    }
+}
+
+#endif // defined(TARGET_LIKE_MBED) && !defined(TARGET_NORDIC)