1  // Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
 2  //
 3  // Licensed under the Apache License, Version 2.0 (the "License");
 4  // you may not use this file except in compliance with the License.
 5  // You may obtain a copy of the License at
 6  //
 7  //     http://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,
11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  // See the License for the specific language governing permissions and
13  // limitations under the License.
14  #include "soc/compare_set.h"
15  #include "soc/spinlock.h"
16  
17  static spinlock_t global_extram_lock = SPINLOCK_INITIALIZER;
18  
19  void compare_and_set_extram(volatile uint32_t *addr, uint32_t compare, uint32_t *set)
20  {
21      uint32_t intlevel, old_value;
22      __asm__ __volatile__ ("rsil %0, " XTSTR(XCHAL_EXCM_LEVEL) "\n"
23                            : "=r"(intlevel));
24  
25  	spinlock_acquire(&global_extram_lock, SPINLOCK_WAIT_FOREVER);
26  
27      old_value = *addr;
28      if (old_value == compare) {
29          *addr = *set;
30      }
31  
32  	spinlock_release(&global_extram_lock);
33  
34  	__asm__ __volatile__ ("memw \n"
35  						"wsr %0, ps\n"
36  						:: "r"(intlevel));
37  
38      *set = old_value;
39  }
40