[PATCH] irqchip: bcm2836: Use a CPU notifier enable IPIs.
Eric Anholt
eric at anholt.net
Mon Jul 27 13:09:49 PDT 2015
Signed-off-by: Eric Anholt <eric at anholt.net>
---
Florian: Thanks! That looks like what we need to squash for Thomas's
feedback. It feels a bit silly to me to avoid enabling IPIs on
not-yet-booted CPUs, despite the fact that Linux itself is what
generates IPIs. However, I've tested it on the 2836 series and it
does work.
drivers/irqchip/irq-bcm2836.c | 31 +++++++++++++++++++++++++------
1 file changed, 25 insertions(+), 6 deletions(-)
diff --git a/drivers/irqchip/irq-bcm2836.c b/drivers/irqchip/irq-bcm2836.c
index 87340b0..0bb0552 100644
--- a/drivers/irqchip/irq-bcm2836.c
+++ b/drivers/irqchip/irq-bcm2836.c
@@ -14,6 +14,7 @@
* GNU General Public License for more details.
*/
+#include <linux/cpu.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/irqchip.h>
@@ -195,6 +196,25 @@ static void bcm2836_arm_irqchip_send_ipi(const struct cpumask *mask,
writel(1 << ipi, mailbox0_base + 16 * cpu);
}
}
+
+/* Unmasks the IPI on the CPU wen it's first brought online. */
+static int bcm2836_arm_irqchip_cpu_notify(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (unsigned long)hcpu;
+ unsigned int int_reg = LOCAL_MAILBOX_INT_CONTROL0;
+ unsigned int mailbox = 0;
+
+ if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
+ bcm2836_arm_irqchip_unmask_per_cpu_irq(int_reg, mailbox, cpu);
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block bcm2836_arm_irqchip_cpu_notifier = {
+ .notifier_call = bcm2836_arm_irqchip_cpu_notify,
+ .priority = 100,
+};
#endif
static const struct irq_domain_ops bcm2836_arm_irqchip_intc_ops = {
@@ -205,13 +225,12 @@ static void
bcm2836_arm_irqchip_smp_init(void)
{
#ifdef CONFIG_SMP
- int i;
+ /* Unmask IPIs to the boot CPU. */
+ bcm2836_arm_irqchip_cpu_notify(&bcm2836_arm_irqchip_cpu_notifier,
+ CPU_STARTING,
+ (void *)smp_processor_id());
+ register_cpu_notifier(&bcm2836_arm_irqchip_cpu_notifier);
- /* unmask IPIs */
- for_each_possible_cpu(i) {
- bcm2836_arm_irqchip_unmask_per_cpu_irq(
- LOCAL_MAILBOX_INT_CONTROL0, 0, i);
- }
set_smp_cross_call(bcm2836_arm_irqchip_send_ipi);
#endif
}
--
2.1.4
More information about the linux-arm-kernel
mailing list