From d9c9fe305c01c30e4f9e8c981a7069ef8e94ca81 Mon Sep 17 00:00:00 2001 From: Michael Sevakis Date: Fri, 18 Jun 2010 03:10:18 +0000 Subject: For multiprocessor targets, do the thread_exit routine such that we don't need to rely on the compiler's good graces to have stack switching be reliable. Only needs a few asm instructions. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26906 a1c6a512-1295-4272-9138-f99709370657 --- firmware/target/arm/thread-pp.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) (limited to 'firmware/target') diff --git a/firmware/target/arm/thread-pp.c b/firmware/target/arm/thread-pp.c index 335f1f3e0a..0c077779e5 100644 --- a/firmware/target/arm/thread-pp.c +++ b/firmware/target/arm/thread-pp.c @@ -199,7 +199,9 @@ static void INIT_ATTR core_thread_init(unsigned int core) } /*--------------------------------------------------------------------------- - * Switches to a stack that always resides in the Rockbox core. + * Switches to a stack that always resides in the Rockbox core then calls + * the final exit routine to actually finish removing the thread from the + * scheduler. * * Needed when a thread suicides on a core other than the main CPU since the * stack used when idling is the stack of the last thread to run. This stack @@ -207,13 +209,24 @@ static void INIT_ATTR core_thread_init(unsigned int core) * to use a stack from an unloaded module until another thread runs on it. *--------------------------------------------------------------------------- */ -static inline void switch_to_idle_stack(const unsigned int core) +static inline void __attribute__((noreturn,always_inline)) + thread_final_exit(struct thread_entry *current) { asm volatile ( - "str sp, [%0] \n" /* save original stack pointer on idle stack */ - "mov sp, %0 \n" /* switch stacks */ - : : "r"(&idle_stacks[core][IDLE_STACK_WORDS-1])); - (void)core; + "cmp %1, #0 \n" /* CPU? */ + "ldrne r0, =cpucache_flush \n" /* No? write back data */ + "movne lr, pc \n" + "bxne r0 \n" + "mov r0, %0 \n" /* copy thread parameter */ + "mov sp, %2 \n" /* switch to idle stack */ + "bl thread_final_exit_do \n" /* finish removal */ + : : "r"(current), + "r"(current->core), + "r"(&idle_stacks[current->core][IDLE_STACK_WORDS]) + : "r0", "r1", "r2", "r3", "ip", "lr"); /* Because of flush call, + force inputs out + of scratch regs */ + while (1); } /*--------------------------------------------------------------------------- -- cgit v1.2.3