From 87d1b1fdb7505d9605ccb58dee80a3311a300248 Mon Sep 17 00:00:00 2001
From: stevstrong <stevestrong@online.de>
Date: Sun, 10 Dec 2017 09:35:48 +0100
Subject: [PATCH] Create new file "atomic.h"

as discussed here: https://github.com/rogerclarkmelbourne/Arduino_STM32/issues/403, taken from http://www.stm32duino.com/viewtopic.php?f=3&t=258&start=10
---
 .../system/libmaple/include/libmaple/atomic.h | 69 +++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 STM32F1/system/libmaple/include/libmaple/atomic.h

diff --git a/STM32F1/system/libmaple/include/libmaple/atomic.h b/STM32F1/system/libmaple/include/libmaple/atomic.h
new file mode 100644
index 0000000..db5e489
--- /dev/null
+++ b/STM32F1/system/libmaple/include/libmaple/atomic.h
@@ -0,0 +1,69 @@
+/*
+* This is port of Dean Camera's ATOMIC_BLOCK macros for AVR to ARM Cortex M3 
+* v1.0
+* Mark Pendrith, Nov 27, 2012.
+*
+* From Mark:
+* >When I ported the macros I emailed Dean to ask what attribution would be
+* >appropriate, and here is his response:
+* >
+* >>Mark,
+* >>I think it's great that you've ported the macros; consider them
+* >>public domain, to do with whatever you wish. I hope you find them useful.
+* >>
+* >>Cheers!
+* >>- Dean 
+*/
+
+#ifndef _CORTEX_M3_ATOMIC_H_
+#define _CORTEX_M3_ATOMIC_H_
+
+static __inline__ uint32_t __get_primask(void) \
+{ uint32_t primask = 0; \
+  __asm__ volatile ("MRS %[result], PRIMASK\n\t":[result]"=r"(primask)::); \
+  return primask; } // returns 0 if interrupts enabled, 1 if disabled
+
+static __inline__ void __set_primask(uint32_t setval) \
+{ __asm__ volatile ("MSR PRIMASK, %[value]\n\t""dmb\n\t""dsb\n\t""isb\n\t"::[value]"r"(setval):); \
+  __asm__ volatile ("" ::: "memory");}
+
+static __inline__ uint32_t __iSeiRetVal(void) \
+{ __asm__ volatile ("CPSIE i\n\t""dmb\n\t""dsb\n\t""isb\n\t"); \
+  __asm__ volatile ("" ::: "memory"); return 1; }
+
+static __inline__ uint32_t __iCliRetVal(void) \
+{ __asm__ volatile ("CPSID i\n\t""dmb\n\t""dsb\n\t""isb\n\t"); \
+  __asm__ volatile ("" ::: "memory"); return 1; }
+
+static __inline__ void    __iSeiParam(const uint32_t *__s) \
+{ __asm__ volatile ("CPSIE i\n\t""dmb\n\t""dsb\n\t""isb\n\t"); \
+  __asm__ volatile ("" ::: "memory"); (void)__s; }
+
+static __inline__ void    __iCliParam(const uint32_t *__s) \
+{ __asm__ volatile ("CPSID i\n\t""dmb\n\t""dsb\n\t""isb\n\t"); \
+  __asm__ volatile ("" ::: "memory"); (void)__s; }
+
+static __inline__ void    __iRestore(const  uint32_t *__s) \
+{ __set_primask(*__s); __asm__ volatile ("dmb\n\t""dsb\n\t""isb\n\t"); \
+  __asm__ volatile ("" ::: "memory"); }
+
+
+#define ATOMIC_BLOCK(type) \
+for ( type, __ToDo = __iCliRetVal(); __ToDo ; __ToDo = 0 )
+
+#define ATOMIC_RESTORESTATE \
+uint32_t primask_save __attribute__((__cleanup__(__iRestore))) = __get_primask()
+
+#define ATOMIC_FORCEON \
+uint32_t primask_save __attribute__((__cleanup__(__iSeiParam))) = 0
+
+#define NONATOMIC_BLOCK(type) \
+for ( type, __ToDo = __iSeiRetVal(); __ToDo ;  __ToDo = 0 )
+   
+#define NONATOMIC_RESTORESTATE \
+uint32_t primask_save __attribute__((__cleanup__(__iRestore))) = __get_primask()
+
+#define NONATOMIC_FORCEOFF \
+uint32_t primask_save __attribute__((__cleanup__(__iCliParam))) = 0
+
+#endif