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 <phil@raspberrypi.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
This commit is contained in:
Phil Elwell 2017-08-08 12:04:55 +01:00 committed by Florian Fainelli
parent 88bbe85dcd
commit 968f76417d
1 changed files with 3 additions and 0 deletions

View File

@ -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;