irq_work: Implement remote queueing

[firefly-linux-kernel-4.4.55.git] / kernel / irq_work.c

diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 126f254614bfbe21690080ba75e51459d800cde8..4b0a890a304a2475c9e45bb171e41ca35f686ab5 100644 (file)
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -16,6 +16,7 @@
 #include <linux/tick.h>
 #include <linux/cpu.h>
 #include <linux/notifier.h>
+#include <linux/smp.h>
 #include <asm/processor.h>
 
 
@@ -55,12 +56,34 @@ void __weak arch_irq_work_raise(void)
         */
 }
 
+#ifdef CONFIG_SMP
 /*
- * Enqueue the irq_work @entry unless it's already pending
+ * Enqueue the irq_work @work on @cpu unless it's already pending
  * somewhere.
  *
  * Can be re-enqueued while the callback is still in progress.
  */
+bool irq_work_queue_on(struct irq_work *work, int cpu)
+{
+       /* All work should have been flushed before going offline */
+       WARN_ON_ONCE(cpu_is_offline(cpu));
+
+       /* Arch remote IPI send/receive backend aren't NMI safe */
+       WARN_ON_ONCE(in_nmi());
+
+       /* Only queue if not already pending */
+       if (!irq_work_claim(work))
+               return false;
+
+       if (llist_add(&work->llnode, &per_cpu(raised_list, cpu)))
+               arch_send_call_function_single_ipi(cpu);
+
+       return true;
+}
+EXPORT_SYMBOL_GPL(irq_work_queue_on);
+#endif
+
+/* Enqueue the irq work @work on the current CPU */
 bool irq_work_queue(struct irq_work *work)
 {
        /* Only queue if not already pending */