From 382d1861af12741af4ff235b9d18f179c0adc4c5 Mon Sep 17 00:00:00 2001 From: Thomas Martitz Date: Wed, 4 Dec 2013 17:06:17 +0100 Subject: kernel: Break out kernel primitives into separate files and move to separate dir. No code changed, just shuffling stuff around. This should make it easier to build only select parts kernel and use different implementations. Change-Id: Ie1f00f93008833ce38419d760afd70062c5e22b5 --- firmware/target/arm/pp/thread-pp.c | 122 ------------------------------------- 1 file changed, 122 deletions(-) (limited to 'firmware/target/arm/pp/thread-pp.c') diff --git a/firmware/target/arm/pp/thread-pp.c b/firmware/target/arm/pp/thread-pp.c index 0836b27204..ed4bdbeac1 100644 --- a/firmware/target/arm/pp/thread-pp.c +++ b/firmware/target/arm/pp/thread-pp.c @@ -51,128 +51,6 @@ static uintptr_t * const idle_stacks[NUM_CORES] = [COP] = cop_idlestackbegin }; -/* Core locks using Peterson's mutual exclusion algorithm */ - -/*--------------------------------------------------------------------------- - * Initialize the corelock structure. - *--------------------------------------------------------------------------- - */ -void corelock_init(struct corelock *cl) -{ - memset(cl, 0, sizeof (*cl)); -} - -#if 1 /* Assembly locks to minimize overhead */ -/*--------------------------------------------------------------------------- - * Wait for the corelock to become free and acquire it when it does. - *--------------------------------------------------------------------------- - */ -void __attribute__((naked)) corelock_lock(struct corelock *cl) -{ - /* Relies on the fact that core IDs are complementary bitmasks (0x55,0xaa) */ - asm volatile ( - "mov r1, %0 \n" /* r1 = PROCESSOR_ID */ - "ldrb r1, [r1] \n" - "strb r1, [r0, r1, lsr #7] \n" /* cl->myl[core] = core */ - "eor r2, r1, #0xff \n" /* r2 = othercore */ - "strb r2, [r0, #2] \n" /* cl->turn = othercore */ - "1: \n" - "ldrb r3, [r0, r2, lsr #7] \n" /* cl->myl[othercore] == 0 ? */ - "cmp r3, #0 \n" /* yes? lock acquired */ - "bxeq lr \n" - "ldrb r3, [r0, #2] \n" /* || cl->turn == core ? */ - "cmp r3, r1 \n" - "bxeq lr \n" /* yes? lock acquired */ - "b 1b \n" /* keep trying */ - : : "i"(&PROCESSOR_ID) - ); - (void)cl; -} - -/*--------------------------------------------------------------------------- - * Try to aquire the corelock. If free, caller gets it, otherwise return 0. - *--------------------------------------------------------------------------- - */ -int __attribute__((naked)) corelock_try_lock(struct corelock *cl) -{ - /* Relies on the fact that core IDs are complementary bitmasks (0x55,0xaa) */ - asm volatile ( - "mov r1, %0 \n" /* r1 = PROCESSOR_ID */ - "ldrb r1, [r1] \n" - "mov r3, r0 \n" - "strb r1, [r0, r1, lsr #7] \n" /* cl->myl[core] = core */ - "eor r2, r1, #0xff \n" /* r2 = othercore */ - "strb r2, [r0, #2] \n" /* cl->turn = othercore */ - "ldrb r0, [r3, r2, lsr #7] \n" /* cl->myl[othercore] == 0 ? */ - "eors r0, r0, r2 \n" /* yes? lock acquired */ - "bxne lr \n" - "ldrb r0, [r3, #2] \n" /* || cl->turn == core? */ - "ands r0, r0, r1 \n" - "streqb r0, [r3, r1, lsr #7] \n" /* if not, cl->myl[core] = 0 */ - "bx lr \n" /* return result */ - : : "i"(&PROCESSOR_ID) - ); - - return 0; - (void)cl; -} - -/*--------------------------------------------------------------------------- - * Release ownership of the corelock - *--------------------------------------------------------------------------- - */ -void __attribute__((naked)) corelock_unlock(struct corelock *cl) -{ - asm volatile ( - "mov r1, %0 \n" /* r1 = PROCESSOR_ID */ - "ldrb r1, [r1] \n" - "mov r2, #0 \n" /* cl->myl[core] = 0 */ - "strb r2, [r0, r1, lsr #7] \n" - "bx lr \n" - : : "i"(&PROCESSOR_ID) - ); - (void)cl; -} - -#else /* C versions for reference */ - -void corelock_lock(struct corelock *cl) -{ - const unsigned int core = CURRENT_CORE; - const unsigned int othercore = 1 - core; - - cl->myl[core] = core; - cl->turn = othercore; - - for (;;) - { - if (cl->myl[othercore] == 0 || cl->turn == core) - break; - } -} - -int corelock_try_lock(struct corelock *cl) -{ - const unsigned int core = CURRENT_CORE; - const unsigned int othercore = 1 - core; - - cl->myl[core] = core; - cl->turn = othercore; - - if (cl->myl[othercore] == 0 || cl->turn == core) - { - return 1; - } - - cl->myl[core] = 0; - return 0; -} - -void corelock_unlock(struct corelock *cl) -{ - cl->myl[CURRENT_CORE] = 0; -} -#endif /* ASM / C selection */ /*--------------------------------------------------------------------------- * Do any device-specific inits for the threads and synchronize the kernel -- cgit v1.2.3