arm: refactor clearing of exception faults to common code

A number of SoCs clear out the Mem/Bus/Usage and Hard Fault exceptions
during init.  Lets refactor that into a common function so we don't have
to keep duplicating it over and over.

Change-Id: Ida908a9092db37447abcf3c9872f36937982f729
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>

arch/arm/include/cortex_m/exc.h

@@ -90,6 +90,28 @@ static ALWAYS_INLINE void _ExcSetup(void)
 #endif
 }
 
+/**
+ * @brief Clear Fault exceptions
+ *
+ * Clear out exceptions for Mem, Bus, Usage and Hard Faults
+ *
+ * @return N/A
+ */
+static ALWAYS_INLINE void _ClearFaults(void)
+{
+#if defined(CONFIG_ARMV6_M)
+#elif defined(CONFIG_ARMV7_M)
+	/* Reset all faults */
+	_ScbMemFaultAllFaultsReset();
+	_ScbBusFaultAllFaultsReset();
+	_ScbUsageFaultAllFaultsReset();
+
+	_ScbHardFaultAllFaultsReset();
+#else
+#error Unknown ARM architecture
+#endif /* CONFIG_ARMV6_M */
+}
+
 #endif /* _ASMLANGUAGE */
 
 #ifdef __cplusplus

arch/arm/soc/atmel_sam3/soc.c

@@ -19,6 +19,7 @@
 #include <soc.h>
 
 #include <arch/cpu.h>
+#include <cortex_m/exc.h>
 
 /**
  * @brief Setup various clock on SoC.
@@ -162,12 +163,7 @@ static int atmel_sam3_init(struct device *arg)
 	__EEFC0->fmr = 0x00000400;
 	__EEFC1->fmr = 0x00000400;
 
-	/* Clear all faults */
-	_ScbMemFaultAllFaultsReset();
-	_ScbBusFaultAllFaultsReset();
-	_ScbUsageFaultAllFaultsReset();
-
-	_ScbHardFaultAllFaultsReset();
+	_ClearFaults();
 
 	/* Setup master clock */
 	clock_init();

arch/arm/soc/nordic_nrf5/nrf52/soc.c

@@ -16,6 +16,7 @@
 #include <device.h>
 #include <init.h>
 #include <soc.h>
+#include <cortex_m/exc.h>
 
 #ifdef CONFIG_RUNTIME_NMI
 extern void _NmiInit(void);
@@ -377,12 +378,7 @@ static int nordicsemi_nrf52_init(struct device *arg)
 	}
 #endif
 
-	/* Reset all faults */
-	_ScbMemFaultAllFaultsReset();
-	_ScbBusFaultAllFaultsReset();
-	_ScbUsageFaultAllFaultsReset();
-
-	_ScbHardFaultAllFaultsReset();
+	_ClearFaults();
 
 	/* Setup master clock */
 	clock_init();

arch/arm/soc/nxp_kinetis/k6x/soc.c

@@ -22,6 +22,7 @@
 #include <fsl_common.h>
 #include <fsl_clock.h>
 #include <arch/cpu.h>
+#include <cortex_m/exc.h>
 
 #define PLLFLLSEL_MCGFLLCLK	(0)
 #define PLLFLLSEL_MCGPLLCLK	(1)
@@ -171,13 +172,7 @@ static int fsl_frdm_k64f_init(struct device *arg)
 	temp_reg |= MPU_CESR_SPERR_MASK;
 	MPU->CESR = temp_reg;
 
-	/* clear all faults */
-
-	_ScbMemFaultAllFaultsReset();
-	_ScbBusFaultAllFaultsReset();
-	_ScbUsageFaultAllFaultsReset();
-
-	_ScbHardFaultAllFaultsReset();
+	_ClearFaults();
 
 	/* Initialize PLL/system clock to 120 MHz */
 	clkInit();

arch/arm/soc/st_stm32/stm32f1/soc.c

@@ -14,6 +14,7 @@
 #include <init.h>
 #include <soc.h>
 #include <arch/cpu.h>
+#include <cortex_m/exc.h>
 
 /**
  * @brief Perform basic hardware initialization at boot.
@@ -31,12 +32,7 @@ static int stm32f1_init(struct device *arg)
 
 	key = irq_lock();
 
-	/* Clear all faults */
-	_ScbMemFaultAllFaultsReset();
-	_ScbBusFaultAllFaultsReset();
-	_ScbUsageFaultAllFaultsReset();
-
-	_ScbHardFaultAllFaultsReset();
+	_ClearFaults();
 
 	/* Install default handler that simply resets the CPU
 	 * if configured in the kernel, NOP otherwise

arch/arm/soc/st_stm32/stm32f3/soc.c

@@ -14,6 +14,7 @@
 #include <init.h>
 #include <soc.h>
 #include <arch/cpu.h>
+#include <cortex_m/exc.h>
 
 /**
  * @brief Perform basic hardware initialization at boot.
@@ -31,12 +32,7 @@ static int stm32f3_init(struct device *arg)
 
 	key = irq_lock();
 
-	/* Clear all faults */
-	_ScbMemFaultAllFaultsReset();
-	_ScbBusFaultAllFaultsReset();
-	_ScbUsageFaultAllFaultsReset();
-
-	_ScbHardFaultAllFaultsReset();
+	_ClearFaults();
 
 	/* Install default handler that simply resets the CPU
 	 * if configured in the kernel, NOP otherwise

arch/arm/soc/st_stm32/stm32f4/soc.c

@@ -15,6 +15,7 @@
 #include <init.h>
 #include <soc.h>
 #include <arch/cpu.h>
+#include <cortex_m/exc.h>
 
 /**
  * @brief Perform basic hardware initialization at boot.
@@ -32,12 +33,7 @@ static int st_stm32f4_init(struct device *arg)
 
 	key = irq_lock();
 
-	/* Clear all faults */
-	_ScbMemFaultAllFaultsReset();
-	_ScbBusFaultAllFaultsReset();
-	_ScbUsageFaultAllFaultsReset();
-
-	_ScbHardFaultAllFaultsReset();
+	_ClearFaults();
 
 	/* Install default handler that simply resets the CPU
 	 * if configured in the kernel, NOP otherwise

arch/arm/soc/st_stm32/stm32l4/soc.c

@@ -15,6 +15,7 @@
 #include <init.h>
 #include <soc.h>
 #include <arch/cpu.h>
+#include <cortex_m/exc.h>
 
 /**
  * @brief Perform basic hardware initialization at boot.
@@ -32,12 +33,7 @@ static int stm32l4_init(struct device *arg)
 
 	key = irq_lock();
 
-	/* Clear all faults */
-	_ScbMemFaultAllFaultsReset();
-	_ScbBusFaultAllFaultsReset();
-	_ScbUsageFaultAllFaultsReset();
-
-	_ScbHardFaultAllFaultsReset();
+	_ClearFaults();
 
 	/* Install default handler that simply resets the CPU
 	 * if configured in the kernel, NOP otherwise