svn commit: r283331 - head/sys/arm/arm
Andrew Turner
andrew at FreeBSD.org
Sat May 23 22:29:00 UTC 2015
Author: andrew
Date: Sat May 23 22:28:59 2015
New Revision: 283331
URL: https://svnweb.freebsd.org/changeset/base/283331
Log:
Use the wait-for-event instruction to put the core we have just enabled
to sleep while it waits to start scheduling. The boot core can then use
the send-event instruction to wake the cores when they should enter the
scheduler.
MFC after: 1 week
Modified:
head/sys/arm/arm/mp_machdep.c
Modified: head/sys/arm/arm/mp_machdep.c
==============================================================================
--- head/sys/arm/arm/mp_machdep.c Sat May 23 21:58:41 2015 (r283330)
+++ head/sys/arm/arm/mp_machdep.c Sat May 23 22:28:59 2015 (r283331)
@@ -185,8 +185,11 @@ init_secondary(int cpu)
atomic_add_rel_32(&mp_naps, 1);
/* Spin until the BSP releases the APs */
- while (!aps_ready)
- ;
+ while (!atomic_load_acq_int(&aps_ready)) {
+#if __ARM_ARCH >= 7
+ __asm __volatile("wfe");
+#endif
+ }
/* Initialize curthread */
KASSERT(PCPU_GET(idlethread) != NULL, ("no idle thread"));
@@ -353,6 +356,10 @@ release_aps(void *dummy __unused)
arm_unmask_irq(i);
}
atomic_store_rel_int(&aps_ready, 1);
+ /* Wake the other threads up */
+#if __ARM_ARCH >= 7
+ armv7_sev();
+#endif
printf("Release APs\n");
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