[PATCH 2/4] irqchip: bcm2836: Add SMP support for the 2836

From: Eric Anholt
Date: Sat Dec 26 2015 - 16:48:13 EST


From: Andrea Merello <andrea.merello@xxxxxxxxx>

The firmware sets the secondaries spinning waiting for a non-NULL
value to show up in the last IPI mailbox.

The original SMP port from the downstream tree was done by Andrea, and
Eric cleaned it up/rewrote it a few times from there.

Signed-off-by: Andrea Merello <andrea.merello@xxxxxxxxx>
Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
---

v2: Merge into another CONFIG_SMP block.

drivers/irqchip/irq-bcm2836.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-bcm2836.c b/drivers/irqchip/irq-bcm2836.c
index 6ec125e..59ac40c 100644
--- a/drivers/irqchip/irq-bcm2836.c
+++ b/drivers/irqchip/irq-bcm2836.c
@@ -53,14 +53,16 @@
/* Same status bits as above, but for FIQ. */
#define LOCAL_FIQ_PENDING0 0x070
/*
- * Mailbox0 write-to-set bits. There are 16 mailboxes, 4 per CPU, and
+ * Mailbox write-to-set bits. There are 16 mailboxes, 4 per CPU, and
* these bits are organized by mailbox number and then CPU number. We
* use mailbox 0 for IPIs. The mailbox's interrupt is raised while
* any bit is set.
*/
#define LOCAL_MAILBOX0_SET0 0x080
-/* Mailbox0 write-to-clear bits. */
+#define LOCAL_MAILBOX3_SET0 0x08c
+/* Mailbox write-to-clear bits. */
#define LOCAL_MAILBOX0_CLR0 0x0c0
+#define LOCAL_MAILBOX3_CLR0 0x0cc

#define LOCAL_IRQ_CNTPSIRQ 0
#define LOCAL_IRQ_CNTPNSIRQ 1
@@ -220,6 +222,24 @@ static struct notifier_block bcm2836_arm_irqchip_cpu_notifier = {
.notifier_call = bcm2836_arm_irqchip_cpu_notify,
.priority = 100,
};
+
+int __init bcm2836_smp_boot_secondary(unsigned int cpu,
+ struct task_struct *idle)
+{
+ unsigned long secondary_startup_phys =
+ (unsigned long)virt_to_phys((void *)secondary_startup);
+
+ dsb();
+ writel(secondary_startup_phys,
+ intc.base + LOCAL_MAILBOX3_SET0 + 16 * cpu);
+
+ return 0;
+}
+
+static const struct smp_operations bcm2836_smp_ops __initconst = {
+ .smp_boot_secondary = bcm2836_smp_boot_secondary,
+};
+
#endif

static const struct irq_domain_ops bcm2836_arm_irqchip_intc_ops = {
@@ -237,6 +257,7 @@ bcm2836_arm_irqchip_smp_init(void)
register_cpu_notifier(&bcm2836_arm_irqchip_cpu_notifier);

set_smp_cross_call(bcm2836_arm_irqchip_send_ipi);
+ smp_set_ops(&bcm2836_smp_ops);
#endif
}

--
2.6.2

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