From bdbf347c228ea12b9cc6fee57147e6cd228ab8f7 Mon Sep 17 00:00:00 2001
From: Richard Barry <ribarry@amazon.com>
Date: Tue, 28 Jun 2016 10:39:25 +0000
Subject: [PATCH] Remove clrex instruction from Cortex-M ports again as it is
 implicit in interrupt entry.

---
 FreeRTOS/Source/portable/CCS/ARM_CM4F/portasm.asm   | 3 ---
 FreeRTOS/Source/portable/GCC/ARM_CM3/port.c         | 1 -
 FreeRTOS/Source/portable/GCC/ARM_CM3_MPU/port.c     | 1 -
 FreeRTOS/Source/portable/GCC/ARM_CM4F/port.c        | 1 -
 FreeRTOS/Source/portable/GCC/ARM_CM4_MPU/port.c     | 1 -
 FreeRTOS/Source/portable/GCC/ARM_CM7/r0p1/port.c    | 1 -
 FreeRTOS/Source/portable/IAR/ARM_CM3/portasm.s      | 1 -
 FreeRTOS/Source/portable/IAR/ARM_CM4F/portasm.s     | 3 ---
 FreeRTOS/Source/portable/IAR/ARM_CM7/r0p1/portasm.s | 3 ---
 FreeRTOS/Source/portable/MikroC/ARM_CM4F/port.c     | 2 --
 FreeRTOS/Source/portable/RVDS/ARM_CM3/port.c        | 1 -
 FreeRTOS/Source/portable/RVDS/ARM_CM4F/port.c       | 3 ---
 FreeRTOS/Source/portable/RVDS/ARM_CM4_MPU/port.c    | 1 -
 FreeRTOS/Source/portable/RVDS/ARM_CM7/r0p1/port.c   | 3 ---
 14 files changed, 25 deletions(-)

diff --git a/FreeRTOS/Source/portable/CCS/ARM_CM4F/portasm.asm b/FreeRTOS/Source/portable/CCS/ARM_CM4F/portasm.asm
index aa42559800..a392583b07 100644
--- a/FreeRTOS/Source/portable/CCS/ARM_CM4F/portasm.asm
+++ b/FreeRTOS/Source/portable/CCS/ARM_CM4F/portasm.asm
@@ -123,9 +123,6 @@ xPortPendSVHandler: .asmfunc
 	;/* Save the new top of stack into the first member of the TCB. */
 	str r0, [r2]
 
-	;/* Ensure thread safety of atomic operations. */
-	clrex
-
 	stmdb sp!, {r3}
 	ldr r0, ulMaxSyscallInterruptPriorityConst
 	ldr r1, [r0]
diff --git a/FreeRTOS/Source/portable/GCC/ARM_CM3/port.c b/FreeRTOS/Source/portable/GCC/ARM_CM3/port.c
index 0888579f87..960717a573 100644
--- a/FreeRTOS/Source/portable/GCC/ARM_CM3/port.c
+++ b/FreeRTOS/Source/portable/GCC/ARM_CM3/port.c
@@ -410,7 +410,6 @@ void xPortPendSVHandler( void )
 	"										\n"
 	"	stmdb r0!, {r4-r11}					\n" /* Save the remaining registers. */
 	"	str r0, [r2]						\n" /* Save the new top of stack into the first member of the TCB. */
-	"	clrex								\n" /* Ensure thread safety of atomic operations. */
 	"										\n"
 	"	stmdb sp!, {r3, r14}				\n"
 	"	mov r0, %0							\n"
diff --git a/FreeRTOS/Source/portable/GCC/ARM_CM3_MPU/port.c b/FreeRTOS/Source/portable/GCC/ARM_CM3_MPU/port.c
index 986b988240..d176bcc356 100644
--- a/FreeRTOS/Source/portable/GCC/ARM_CM3_MPU/port.c
+++ b/FreeRTOS/Source/portable/GCC/ARM_CM3_MPU/port.c
@@ -450,7 +450,6 @@ void xPortPendSVHandler( void )
 		"	mrs r1, control						\n"
 		"	stmdb r0!, {r1, r4-r11}				\n" /* Save the remaining registers. */
 		"	str r0, [r2]						\n" /* Save the new top of stack into the first member of the TCB. */
-		"	clrex								\n" /* Ensure thread safety of atomic operations. */
 		"										\n"
 		"	stmdb sp!, {r3, r14}				\n"
 		"	mov r0, %0							\n"
diff --git a/FreeRTOS/Source/portable/GCC/ARM_CM4F/port.c b/FreeRTOS/Source/portable/GCC/ARM_CM4F/port.c
index 2cb58683e7..952c60b8bd 100644
--- a/FreeRTOS/Source/portable/GCC/ARM_CM4F/port.c
+++ b/FreeRTOS/Source/portable/GCC/ARM_CM4F/port.c
@@ -450,7 +450,6 @@ void xPortPendSVHandler( void )
 	"										\n"
 	"	stmdb r0!, {r4-r11, r14}			\n" /* Save the core registers. */
 	"	str r0, [r2]						\n" /* Save the new top of stack into the first member of the TCB. */
-	"	clrex								\n" /* Ensure thread safety of atomic operations. */
 	"										\n"
 	"	stmdb sp!, {r3}						\n"
 	"	mov r0, %0 							\n"
diff --git a/FreeRTOS/Source/portable/GCC/ARM_CM4_MPU/port.c b/FreeRTOS/Source/portable/GCC/ARM_CM4_MPU/port.c
index a6b4c5a84e..babea315fb 100644
--- a/FreeRTOS/Source/portable/GCC/ARM_CM4_MPU/port.c
+++ b/FreeRTOS/Source/portable/GCC/ARM_CM4_MPU/port.c
@@ -477,7 +477,6 @@ void xPortPendSVHandler( void )
 		"	mrs r1, control						\n"
 		"	stmdb r0!, {r1, r4-r11, r14}		\n" /* Save the remaining registers. */
 		"	str r0, [r2]						\n" /* Save the new top of stack into the first member of the TCB. */
-		"	clrex								\n" /* Ensure thread safety of atomic operations. */
 		"										\n"
 		"	stmdb sp!, {r3}						\n"
 		"	mov r0, %0							\n"
diff --git a/FreeRTOS/Source/portable/GCC/ARM_CM7/r0p1/port.c b/FreeRTOS/Source/portable/GCC/ARM_CM7/r0p1/port.c
index 51d1c1a661..86fb9cc6bb 100644
--- a/FreeRTOS/Source/portable/GCC/ARM_CM7/r0p1/port.c
+++ b/FreeRTOS/Source/portable/GCC/ARM_CM7/r0p1/port.c
@@ -438,7 +438,6 @@ void xPortPendSVHandler( void )
 	"										\n"
 	"	stmdb r0!, {r4-r11, r14}			\n" /* Save the core registers. */
 	"	str r0, [r2]						\n" /* Save the new top of stack into the first member of the TCB. */
-	"	clrex								\n" /* Ensure thread safety of atomic operations. */
 	"										\n"
 	"	stmdb sp!, {r3}						\n"
 	"	mov r0, %0 							\n"
diff --git a/FreeRTOS/Source/portable/IAR/ARM_CM3/portasm.s b/FreeRTOS/Source/portable/IAR/ARM_CM3/portasm.s
index 756602121d..cf7a6a3a1b 100644
--- a/FreeRTOS/Source/portable/IAR/ARM_CM3/portasm.s
+++ b/FreeRTOS/Source/portable/IAR/ARM_CM3/portasm.s
@@ -91,7 +91,6 @@ xPortPendSVHandler:
 
 	stmdb r0!, {r4-r11}				/* Save the remaining registers. */
 	str r0, [r2]					/* Save the new top of stack into the first member of the TCB. */
-	clrex							/* Ensure thread safety of atomic operations. */
 
 	stmdb sp!, {r3, r14}
 	mov r0, #configMAX_SYSCALL_INTERRUPT_PRIORITY
diff --git a/FreeRTOS/Source/portable/IAR/ARM_CM4F/portasm.s b/FreeRTOS/Source/portable/IAR/ARM_CM4F/portasm.s
index a6e07773db..758d6fa971 100644
--- a/FreeRTOS/Source/portable/IAR/ARM_CM4F/portasm.s
+++ b/FreeRTOS/Source/portable/IAR/ARM_CM4F/portasm.s
@@ -101,9 +101,6 @@ xPortPendSVHandler:
 	/* Save the new top of stack into the first member of the TCB. */
 	str r0, [r2]
 
-	/* Ensure thread safety of atomic operations. */
-	clrex
-
 	stmdb sp!, {r3}
 	mov r0, #configMAX_SYSCALL_INTERRUPT_PRIORITY
 	msr basepri, r0
diff --git a/FreeRTOS/Source/portable/IAR/ARM_CM7/r0p1/portasm.s b/FreeRTOS/Source/portable/IAR/ARM_CM7/r0p1/portasm.s
index e90dfb2612..2ab809a0e3 100644
--- a/FreeRTOS/Source/portable/IAR/ARM_CM7/r0p1/portasm.s
+++ b/FreeRTOS/Source/portable/IAR/ARM_CM7/r0p1/portasm.s
@@ -101,9 +101,6 @@ xPortPendSVHandler:
 	/* Save the new top of stack into the first member of the TCB. */
 	str r0, [r2]
 
-	/* Ensure thread safety of atomic operations. */
-	clrex
-
 	stmdb sp!, {r3}
 	mov r0, #configMAX_SYSCALL_INTERRUPT_PRIORITY
 	cpsid i
diff --git a/FreeRTOS/Source/portable/MikroC/ARM_CM4F/port.c b/FreeRTOS/Source/portable/MikroC/ARM_CM4F/port.c
index 8bd991d3ca..bb69933481 100644
--- a/FreeRTOS/Source/portable/MikroC/ARM_CM4F/port.c
+++ b/FreeRTOS/Source/portable/MikroC/ARM_CM4F/port.c
@@ -458,8 +458,6 @@ void xPortPendSVHandler( void ) iv IVT_INT_PendSV ics ICS_OFF
 
 	str r0, [r2]			 /* Save the new top of stack into the first member of the TCB. */
 
-	clrex					/* Ensure thread safety of atomic operations. */
-
 	stmdb sp!, (r3)
 	ldr r0, =_ucMaxSyscallInterruptPriority
 	ldr r1, [r0]
diff --git a/FreeRTOS/Source/portable/RVDS/ARM_CM3/port.c b/FreeRTOS/Source/portable/RVDS/ARM_CM3/port.c
index 8ce6d098d2..e15b91a16c 100644
--- a/FreeRTOS/Source/portable/RVDS/ARM_CM3/port.c
+++ b/FreeRTOS/Source/portable/RVDS/ARM_CM3/port.c
@@ -407,7 +407,6 @@ __asm void xPortPendSVHandler( void )
 
 	stmdb r0!, {r4-r11}			/* Save the remaining registers. */
 	str r0, [r2]				/* Save the new top of stack into the first member of the TCB. */
-	clrex						/* Ensure thread safety of atomic operations. */
 
 	stmdb sp!, {r3, r14}
 	mov r0, #configMAX_SYSCALL_INTERRUPT_PRIORITY
diff --git a/FreeRTOS/Source/portable/RVDS/ARM_CM4F/port.c b/FreeRTOS/Source/portable/RVDS/ARM_CM4F/port.c
index aaf9efd21e..6902f97894 100644
--- a/FreeRTOS/Source/portable/RVDS/ARM_CM4F/port.c
+++ b/FreeRTOS/Source/portable/RVDS/ARM_CM4F/port.c
@@ -479,9 +479,6 @@ __asm void xPortPendSVHandler( void )
 	/* Save the new top of stack into the first member of the TCB. */
 	str r0, [r2]
 
-	/* Ensure thread safety of atomic operations. */
-	clrex
-
 	stmdb sp!, {r3}
 	mov r0, #configMAX_SYSCALL_INTERRUPT_PRIORITY
 	msr basepri, r0
diff --git a/FreeRTOS/Source/portable/RVDS/ARM_CM4_MPU/port.c b/FreeRTOS/Source/portable/RVDS/ARM_CM4_MPU/port.c
index 0623859e84..3cd9240565 100644
--- a/FreeRTOS/Source/portable/RVDS/ARM_CM4_MPU/port.c
+++ b/FreeRTOS/Source/portable/RVDS/ARM_CM4_MPU/port.c
@@ -492,7 +492,6 @@ __asm void xPortPendSVHandler( void )
 	mrs r1, control
 	stmdb r0!, {r1, r4-r11, r14}	/* Save the remaining registers. */
 	str r0, [r2]					/* Save the new top of stack into the first member of the TCB. */
-	clrex							/* Ensure thread safety of atomic operations. */
 
 	stmdb sp!, {r3}
 	mov r0, #configMAX_SYSCALL_INTERRUPT_PRIORITY
diff --git a/FreeRTOS/Source/portable/RVDS/ARM_CM7/r0p1/port.c b/FreeRTOS/Source/portable/RVDS/ARM_CM7/r0p1/port.c
index 9f0dc3330e..133f61ea8c 100644
--- a/FreeRTOS/Source/portable/RVDS/ARM_CM7/r0p1/port.c
+++ b/FreeRTOS/Source/portable/RVDS/ARM_CM7/r0p1/port.c
@@ -463,9 +463,6 @@ __asm void xPortPendSVHandler( void )
 	/* Save the new top of stack into the first member of the TCB. */
 	str r0, [r2]
 
-	/* Ensure thread safety of atomic operations. */
-	clrex
-
 	stmdb sp!, {r3}
 	mov r0, #configMAX_SYSCALL_INTERRUPT_PRIORITY
 	cpsid i