STM32 FLASH API : add critical sections

See PR #13802 (for F4 board)

Concerned boards are

STM32F0
STM32F1
STM32F2
STM32F3
STM32F4
STM32F7
STM32G0
STM32G4
STM32H7
STM32L0
STM32L1
STM32L4
STM32L5

Adding test of return code of HAL_FLASH_Lock() function
Adding board STM32F4
Running AStyle

targets/TARGET_STM/TARGET_STM32F0/flash_api.c

@@ -30,27 +30,6 @@
 // Minimum number of bytes to be programmed at a time
 #define MIN_PROG_SIZE (4U)
 
-static int32_t flash_unlock(void)
-{
-    /* Allow Access to Flash control registers and user Flash */
-    if (HAL_FLASH_Unlock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
-static int32_t flash_lock(void)
-{
-    /* Disable the Flash option control register access (recommended to protect
-    the option Bytes against possible unwanted operations) */
-    if (HAL_FLASH_Lock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
 int32_t flash_init(flash_t *obj)
 {
     return 0;
@@ -71,10 +50,12 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     // Clear Flash status register's flags
     __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_EOP | FLASH_FLAG_WRPERR | FLASH_FLAG_PGERR);
 
@@ -93,7 +74,11 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         status = -1;
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }
@@ -111,10 +96,12 @@ int32_t flash_program_page(flash_t *obj, uint32_t address, const uint8_t *data,
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Program the user Flash area word by word */
     StartAddress = address;
 
@@ -145,7 +132,11 @@ int32_t flash_program_page(flash_t *obj, uint32_t address, const uint8_t *data,
         }
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }

targets/TARGET_STM/TARGET_STM32F1/flash_api.c

@@ -30,27 +30,6 @@
 // Minimum number of bytes to be programmed at a time
 #define MIN_PROG_SIZE (4U)
 
-static int32_t flash_unlock(void)
-{
-    /* Allow Access to Flash control registers and user Flash */
-    if (HAL_FLASH_Unlock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
-static int32_t flash_lock(void)
-{
-    /* Disable the Flash option control register access (recommended to protect
-    the option Bytes against possible unwanted operations) */
-    if (HAL_FLASH_Lock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
 int32_t flash_init(flash_t *obj)
 {
     return 0;
@@ -71,10 +50,12 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     // Clear Flash status register's flags
     __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_EOP | FLASH_FLAG_WRPERR | FLASH_FLAG_PGERR | FLASH_FLAG_OPTVERR);
 
@@ -93,7 +74,11 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         status = -1;
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }
@@ -111,10 +96,12 @@ int32_t flash_program_page(flash_t *obj, uint32_t address, const uint8_t *data,
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Program the user Flash area word by word */
     StartAddress = address;
 
@@ -145,7 +132,11 @@ int32_t flash_program_page(flash_t *obj, uint32_t address, const uint8_t *data,
         }
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }

targets/TARGET_STM/TARGET_STM32F2/flash_api.c

@@ -25,27 +25,6 @@
 static uint32_t GetSector(uint32_t Address);
 static uint32_t GetSectorSize(uint32_t Sector);
 
-static int32_t flash_unlock(void)
-{
-    /* Allow Access to Flash control registers and user Falsh */
-    if (HAL_FLASH_Unlock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
-static int32_t flash_lock(void)
-{
-    /* Disable the Flash option control register access (recommended to protect
-    the option Bytes against possible unwanted operations) */
-    if (HAL_FLASH_Lock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
 int32_t flash_init(flash_t *obj)
 {
     return 0;
@@ -67,10 +46,12 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Get the 1st sector to erase */
     FirstSector = GetSector(address);
 
@@ -84,7 +65,11 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         status = -1;
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }
@@ -97,10 +82,12 @@ int32_t flash_program_page(flash_t *obj, uint32_t address, const uint8_t *data,
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Note: If an erase operation in Flash memory also concerns data in the data or instruction cache,
        you have to make sure that these data are rewritten before they are accessed during code
        execution. If this cannot be done safely, it is recommended to flush the caches by setting the
@@ -124,7 +111,11 @@ int32_t flash_program_page(flash_t *obj, uint32_t address, const uint8_t *data,
         }
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }

targets/TARGET_STM/TARGET_STM32F3/flash_api.c

@@ -30,27 +30,6 @@
 // Minimum number of bytes to be programmed at a time
 #define MIN_PROG_SIZE (4U)
 
-static int32_t flash_unlock(void)
-{
-    /* Allow Access to Flash control registers and user Flash */
-    if (HAL_FLASH_Unlock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
-static int32_t flash_lock(void)
-{
-    /* Disable the Flash option control register access (recommended to protect
-    the option Bytes against possible unwanted operations) */
-    if (HAL_FLASH_Lock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
 int32_t flash_init(flash_t *obj)
 {
     return 0;
@@ -71,10 +50,12 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     // Clear Flash status register's flags
     __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_EOP | FLASH_FLAG_WRPERR | FLASH_FLAG_PGERR);
 
@@ -93,7 +74,11 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         status = -1;
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }
@@ -111,10 +96,12 @@ int32_t flash_program_page(flash_t *obj, uint32_t address, const uint8_t *data,
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Program the user Flash area word by word */
     StartAddress = address;
 
@@ -145,7 +132,11 @@ int32_t flash_program_page(flash_t *obj, uint32_t address, const uint8_t *data,
         }
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }

targets/TARGET_STM/TARGET_STM32F4/flash_api.c

@@ -65,7 +65,9 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
 
     core_util_critical_section_exit();
 
-    HAL_FLASH_Lock();
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }
@@ -83,6 +85,7 @@ int32_t flash_program_page(flash_t *obj, uint32_t address, const uint8_t *data,
     }
 
     core_util_critical_section_enter();
+
     /* Note: If an erase operation in Flash memory also concerns data in the data or instruction cache,
        you have to make sure that these data are rewritten before they are accessed during code
        execution. If this cannot be done safely, it is recommended to flush the caches by setting the
@@ -108,7 +111,9 @@ int32_t flash_program_page(flash_t *obj, uint32_t address, const uint8_t *data,
 
     core_util_critical_section_exit();
 
-    HAL_FLASH_Lock();
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }

targets/TARGET_STM/TARGET_STM32F7/flash_api.c

@@ -61,27 +61,6 @@ int32_t flash_free(flash_t *obj)
     return 0;
 }
 
-static int32_t flash_unlock(void)
-{
-    /* Allow Access to Flash control registers and user Falsh */
-    if (HAL_FLASH_Unlock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
-static int32_t flash_lock(void)
-{
-    /* Disable the Flash option control register access (recommended to protect
-    the option Bytes against possible unwanted operations) */
-    if (HAL_FLASH_Lock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
 int32_t flash_erase_sector(flash_t *obj, uint32_t address)
 {
     /* Variable used for Erase procedure */
@@ -94,10 +73,12 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Note: If an erase operation in Flash memory also concerns data in the data or instruction cache,
        you have to make sure that these data are rewritten before they are accessed during code
        execution. If this cannot be done safely, it is recommended to flush the caches by setting the
@@ -122,7 +103,11 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
     SCB_CleanInvalidateDCache_by_Addr((uint32_t *)GetSectorBase(SectorId), GetSectorSize(SectorId));
     SCB_InvalidateICache();
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }
@@ -138,10 +123,12 @@ int32_t flash_program_page(flash_t *obj, uint32_t address, const uint8_t *data,
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Note: If an erase operation in Flash memory also concerns data in the data or instruction cache,
        you have to make sure that these data are rewritten before they are accessed during code
        execution. If this cannot be done safely, it is recommended to flush the caches by setting the
@@ -164,7 +151,11 @@ int32_t flash_program_page(flash_t *obj, uint32_t address, const uint8_t *data,
     SCB_CleanInvalidateDCache_by_Addr((uint32_t *)StartAddress, FullSize);
     SCB_InvalidateICache();
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }

targets/TARGET_STM/TARGET_STM32G0/flash_api.c

@@ -34,27 +34,6 @@ int32_t flash_free(flash_t *obj)
     return 0;
 }
 
-static int32_t flash_unlock(void)
-{
-    /* Allow Access to Flash control registers and user Falsh */
-    if (HAL_FLASH_Unlock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
-static int32_t flash_lock(void)
-{
-    /* Disable the Flash option control register access (recommended to protect
-    the option Bytes against possible unwanted operations) */
-    if (HAL_FLASH_Lock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
 int32_t flash_erase_sector(flash_t *obj, uint32_t address)
 {
     uint32_t PAGEError = 0;
@@ -66,10 +45,12 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Clear OPTVERR bit set on virgin samples */
     __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_OPTVERR);
 
@@ -88,7 +69,11 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         status = -1;
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 
@@ -109,10 +94,12 @@ int32_t flash_program_page(flash_t *obj, uint32_t address,
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Program the user Flash area word by word */
     StartAddress = address;
 
@@ -143,7 +130,11 @@ int32_t flash_program_page(flash_t *obj, uint32_t address,
         }
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }

targets/TARGET_STM/TARGET_STM32G4/flash_api.c

@@ -91,27 +91,6 @@ int32_t flash_free(flash_t *obj)
     return 0;
 }
 
-static int32_t flash_unlock(void)
-{
-    /* Allow Access to Flash control registers and user Falsh */
-    if (HAL_FLASH_Unlock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
-static int32_t flash_lock(void)
-{
-    /* Disable the Flash option control register access (recommended to protect
-    the option Bytes against possible unwanted operations) */
-    if (HAL_FLASH_Lock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
 /** Erase one sector starting at defined address
  *
  * The address should be at sector boundary. This function does not do any check for address alignments
@@ -131,10 +110,12 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Clear error programming flags */
     __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_ALL_ERRORS);
 
@@ -158,7 +139,11 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         status = -1;
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }
@@ -189,10 +174,12 @@ int32_t flash_program_page(flash_t *obj, uint32_t address,
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Clear error programming flags */
     __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_ALL_ERRORS);
 
@@ -229,7 +216,11 @@ int32_t flash_program_page(flash_t *obj, uint32_t address,
         }
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }

targets/TARGET_STM/TARGET_STM32H7/flash_api.c

@@ -62,6 +62,7 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
     while (LL_HSEM_1StepLock(HSEM, CFG_HW_FLASH_SEMID)) {
     }
 #endif /* DUAL_CORE */
+
     if (HAL_FLASH_Unlock() != HAL_OK) {
 #if defined(DUAL_CORE)
         LL_HSEM_ReleaseLock(HSEM, CFG_HW_FLASH_SEMID, HSEM_CR_COREID_CURRENT);
@@ -69,6 +70,8 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Fill EraseInit structure */
     EraseInitStruct.TypeErase = FLASH_TYPEERASE_SECTORS;
 #if defined (FLASH_CR_PSIZE)
@@ -97,9 +100,12 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
     SCB_InvalidateICache();
 #endif /* DUAL_CORE */
 
+    core_util_critical_section_exit();
 
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
-    HAL_FLASH_Lock();
 #if defined(DUAL_CORE)
     LL_HSEM_ReleaseLock(HSEM, CFG_HW_FLASH_SEMID, HSEM_CR_COREID_CURRENT);
 #endif /* DUAL_CORE */
@@ -128,6 +134,8 @@ int32_t flash_program_page(flash_t *obj, uint32_t address, const uint8_t *data,
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     StartAddress = address;
     while ((address < (StartAddress + size)) && (status == 0)) {
         if (HAL_FLASH_Program(FLASH_TYPEPROGRAM_FLASHWORD, address, (uint32_t)data) == HAL_OK) {
@@ -148,7 +156,12 @@ int32_t flash_program_page(flash_t *obj, uint32_t address, const uint8_t *data,
     SCB_InvalidateICache();
 #endif /* DUAL_CORE */
 
-    HAL_FLASH_Lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
+
 #if defined(DUAL_CORE)
     LL_HSEM_ReleaseLock(HSEM, CFG_HW_FLASH_SEMID, HSEM_CR_COREID_CURRENT);
 #endif /* DUAL_CORE */

targets/TARGET_STM/TARGET_STM32L0/flash_api.c

@@ -36,27 +36,6 @@ int32_t flash_free(flash_t *obj)
     return 0;
 }
 
-static int32_t flash_unlock(void)
-{
-    /* Allow Access to Flash control registers and user Falsh */
-    if (HAL_FLASH_Unlock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
-static int32_t flash_lock(void)
-{
-    /* Disable the Flash option control register access (recommended to protect
-    the option Bytes against possible unwanted operations) */
-    if (HAL_FLASH_Lock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
 int32_t flash_erase_sector(flash_t *obj, uint32_t address)
 {
     uint32_t PAGEError = 0;
@@ -68,10 +47,12 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Clear OPTVERR bit set on virgin samples */
     __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_OPTVERR);
 
@@ -90,7 +71,11 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         status = -1;
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 
@@ -111,10 +96,12 @@ int32_t flash_program_page(flash_t *obj, uint32_t address,
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Program the user Flash area word by word */
     StartAddress = address;
 
@@ -145,7 +132,11 @@ int32_t flash_program_page(flash_t *obj, uint32_t address,
         }
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }

targets/TARGET_STM/TARGET_STM32L1/flash_api.c

@@ -36,27 +36,6 @@ int32_t flash_free(flash_t *obj)
     return 0;
 }
 
-static int32_t flash_unlock(void)
-{
-    /* Allow Access to Flash control registers and user Falsh */
-    if (HAL_FLASH_Unlock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
-static int32_t flash_lock(void)
-{
-    /* Disable the Flash option control register access (recommended to protect
-    the option Bytes against possible unwanted operations) */
-    if (HAL_FLASH_Lock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
 int32_t flash_erase_sector(flash_t *obj, uint32_t address)
 {
     uint32_t PAGEError = 0;
@@ -68,10 +47,12 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_OPTVERR | FLASH_FLAG_EOP | FLASH_FLAG_PGAERR | FLASH_FLAG_WRPERR);
     /* MBED HAL erases 1 sector at a time */
     /* Fill EraseInit structure*/
@@ -88,7 +69,11 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         status = -1;
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 
@@ -109,10 +94,12 @@ int32_t flash_program_page(flash_t *obj, uint32_t address,
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Program the user Flash area word by word */
     StartAddress = address;
 
@@ -143,7 +130,11 @@ int32_t flash_program_page(flash_t *obj, uint32_t address,
         }
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }

targets/TARGET_STM/TARGET_STM32L4/flash_api.c

@@ -94,27 +94,6 @@ int32_t flash_free(flash_t *obj)
     return 0;
 }
 
-static int32_t flash_unlock(void)
-{
-    /* Allow Access to Flash control registers and user Falsh */
-    if (HAL_FLASH_Unlock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
-static int32_t flash_lock(void)
-{
-    /* Disable the Flash option control register access (recommended to protect
-    the option Bytes against possible unwanted operations) */
-    if (HAL_FLASH_Lock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
 /** Erase one sector starting at defined address
  *
  * The address should be at sector boundary. This function does not do any check for address alignments
@@ -134,10 +113,12 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Clear error programming flags */
     __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_ALL_ERRORS);
 
@@ -161,7 +142,11 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         status = -1;
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }
@@ -192,10 +177,12 @@ int32_t flash_program_page(flash_t *obj, uint32_t address,
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Clear error programming flags */
     __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_ALL_ERRORS);
 
@@ -232,7 +219,11 @@ int32_t flash_program_page(flash_t *obj, uint32_t address,
         }
     }
 
-    flash_lock();
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
+        return -1;
+    }
 
     return status;
 }

targets/TARGET_STM/TARGET_STM32L5/flash_api.c

@@ -93,27 +93,6 @@ int32_t flash_free(flash_t *obj)
     return 0;
 }
 
-static int32_t flash_unlock(void)
-{
-    /* Allow Access to Flash control registers and user Falsh */
-    if (HAL_FLASH_Unlock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
-static int32_t flash_lock(void)
-{
-    /* Disable the Flash option control register access (recommended to protect
-    the option Bytes against possible unwanted operations) */
-    if (HAL_FLASH_Lock()) {
-        return -1;
-    } else {
-        return 0;
-    }
-}
-
 /** Erase one sector starting at defined address
  *
  * The address should be at sector boundary. This function does not do any check for address alignments
@@ -131,10 +110,12 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Clear error programming flags */
     __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_ALL_ERRORS);
 
@@ -154,7 +135,9 @@ int32_t flash_erase_sector(flash_t *obj, uint32_t address)
         return -1;
     }
 
-    if (flash_lock() != HAL_OK) {
+    core_util_critical_section_exit();
+
+    if (HAL_FLASH_Lock() != HAL_OK) {
         return -1;
     }
 
@@ -186,10 +169,12 @@ int32_t flash_program_page(flash_t *obj, uint32_t address,
         return -1;
     }
 
-    if (flash_unlock() != HAL_OK) {
+    if (HAL_FLASH_Unlock() != HAL_OK) {
         return -1;
     }
 
+    core_util_critical_section_enter();
+
     /* Clear error programming flags */
     __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_ALL_ERRORS);
 
@@ -226,7 +211,11 @@ int32_t flash_program_page(flash_t *obj, uint32_t address,
         }
     }
 
-    status = flash_unlock();
+    if (HAL_FLASH_Unlock() != HAL_OK) {
+        return -1;
+    }
+
+    core_util_critical_section_enter();
 
     return status;
 }