1 // Copyright 2023 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14
15 #include "pw_interrupt/context.h"
16
17 #include <xtensa/config/core.h>
18 #include <xtensa/hal.h>
19
20 #include <cstdint>
21
22 namespace pw::interrupt {
23
InInterruptContext()24 bool InInterruptContext() {
25 // xthal_intlevel_get returns the current interrupt level of the processor
26 // (value of PS.INTLEVEL register). C based handlers are always dispatched
27 // from an interrupt level below XCHAL_EXCM_LEVEL - handlers running above
28 // this level must be written in assembly. The interrupt level is set to zero
29 // when interrupts are enabled but the core isn't currently procesing one.
30 const uint32_t int_level = xthal_intlevel_get();
31 return (int_level < XCHAL_EXCM_LEVEL) && (int_level > 0);
32 }
33
34 } // namespace pw::interrupt
35