From 968f76417df671338ea3a1fd33b2c93a048cc1b1 Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Tue, 8 Aug 2017 12:04:55 +0100 Subject: [PATCH] ARM: bcm2836: Send event when onlining other cores Secondary cores should enter a low-power idle state when waiting to be started. The "wfe" instruction causes a core to wait until an event or interrupt arrives before continuing to the next instruction, and the "sev" instruction sends a wakeup event to the other cores. Add an "sev" (and a memory barrier) to bcm2836_boot_secondary, the function that wakes the waiting cores during booting. This is required if the secondary cores are sitting in "wfe", and harmless if not. Signed-off-by: Phil Elwell Signed-off-by: Eric Anholt Reviewed-by: Eric Anholt --- arch/arm/mach-bcm/platsmp.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm/mach-bcm/platsmp.c b/arch/arm/mach-bcm/platsmp.c index 34506a608fea..7d954830eb57 100644 --- a/arch/arm/mach-bcm/platsmp.c +++ b/arch/arm/mach-bcm/platsmp.c @@ -312,6 +312,9 @@ static int bcm2836_boot_secondary(unsigned int cpu, struct task_struct *idle) writel(virt_to_phys(secondary_startup), intc_base + LOCAL_MAILBOX3_SET0 + 16 * cpu); + dsb(sy); + sev(); + iounmap(intc_base); return 0;