From mboxrd@z Thu Jan 1 00:00:00 1970 From: elder@linaro.org (Alex Elder) Date: Tue, 8 Apr 2014 17:31:28 -0500 Subject: [RFC PATCH RESEND] ARM: spear: send SGI to trigger secondary CPU start Message-ID: <1396996288-32020-1-git-send-email-elder@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The ARM spear machine uses the "holding pen" mechanism for starting secondary CPUs. Most implementations indicate it's a secondary core's time to start by writing its CPU id into a location and then signaling the core with a software-generated interrupt. The spear code does not send the signal. Comments elsewhere in the code seem to indicate it should: The BootMonitor waits until it receives a soft interrupt, and then the secondary CPU branches to this address. I suspect this is an oversight, and this patch proposes a remedy. *** I need the attention of a maintainer to verify this *** because I am unable to test this proposed change. Signed-off-by: Alex Elder --- arch/arm/mach-spear/platsmp.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/mach-spear/platsmp.c b/arch/arm/mach-spear/platsmp.c index 5c4a198..c9064fe 100644 --- a/arch/arm/mach-spear/platsmp.c +++ b/arch/arm/mach-spear/platsmp.c @@ -62,6 +62,8 @@ static int spear13xx_boot_secondary(unsigned int cpu, struct task_struct *idle) flush_cache_all(); outer_flush_all(); + arch_send_wakeup_ipi_mask(cpumask_of(cpu)); + timeout = jiffies + (1 * HZ); while (time_before(jiffies, timeout)) { smp_rmb(); -- 1.7.9.5