From 11b05f11d4d6d61717e345d20f492977b95ab131 Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Thu, 8 May 2014 10:11:13 +0200 Subject: score: Fix CPU context usage on SMP We must not alter the is executing indicator in _CPU_Context_Initialize() since this would cause an invalid state during a self restart. The is executing indicator must be valid at creation time since otherwise _Thread_Kill_zombies() uses an undefined value for not started threads. This could result in a system life lock. --- cpukit/score/cpu/arm/cpu_asm.S | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) (limited to 'cpukit/score/cpu/arm/cpu_asm.S') diff --git a/cpukit/score/cpu/arm/cpu_asm.S b/cpukit/score/cpu/arm/cpu_asm.S index f2c4afe39e..0df5ebbb87 100644 --- a/cpukit/score/cpu/arm/cpu_asm.S +++ b/cpukit/score/cpu/arm/cpu_asm.S @@ -68,31 +68,29 @@ DEFINE_FUNCTION_ARM(_CPU_Context_switch) #endif #ifdef RTEMS_SMP - /* Indicate that this context is no longer executing */ + /* The executing context no longer executes on this processor */ dmb mov r3, #0 strb r3, [r0, #ARM_CONTEXT_CONTROL_IS_EXECUTING_OFFSET] -#endif - -/* Start restoring context */ -_restore: -#ifdef ARM_MULTILIB_HAS_LOAD_STORE_EXCLUSIVE - clrex -#endif -#ifdef RTEMS_SMP - /* Wait for context to stop execution if necessary */ + /* Wait for heir context to stop execution */ 1: ldrb r3, [r1, #ARM_CONTEXT_CONTROL_IS_EXECUTING_OFFSET] cmp r3, #0 bne 1b - /* Indicate that this context is executing */ + /* The heir context executes now on this processor */ dmb mov r3, #1 strb r3, [r1, #ARM_CONTEXT_CONTROL_IS_EXECUTING_OFFSET] #endif +/* Start restoring context */ +_restore: +#ifdef ARM_MULTILIB_HAS_LOAD_STORE_EXCLUSIVE + clrex +#endif + #ifdef ARM_MULTILIB_HAS_THREAD_ID_REGISTER ldr r3, [r1, #ARM_CONTEXT_CONTROL_THREAD_ID_OFFSET] mcr p15, 0, r3, c13, c0, 3 -- cgit v1.2.3