Merge tag 'v3.18-rc4' into patchwork

Needed due to some important regression fixes at RC core.

* commit 'v3.18-rc4': (587 commits)
  Linux 3.18-rc4
  ARM: dts: zynq: Enable PL clocks for Parallella
  tiny: rename ENABLE_DEV_COREDUMP to ALLOW_DEV_COREDUMP
  tiny: reverse logic for DISABLE_DEV_COREDUMP
  i2c: core: Dispose OF IRQ mapping at client removal time
  i2c: at91: don't account as iowait
  i2c: remove FSF address
  USB: Update default usb-storage delay_use value in kernel-parameters.txt
  sysfs: driver core: Fix glue dir race condition by gdp_mutex
  MIPS: Fix build with binutils 2.24.51+
  xfs: track bulkstat progress by agino
  xfs: bulkstat error handling is broken
  xfs: bulkstat main loop logic is a mess
  xfs: bulkstat chunk-formatter has issues
  xfs: bulkstat chunk formatting cursor is broken
  xfs: bulkstat btree walk doesn't terminate
  mm: Fix comment before truncate_setsize()
  USB: cdc-acm: add quirk for control-line state requests
  tty: Fix pty master poll() after slave closes v2
  MIPS: R3000: Fix debug output for Virtual page number
  ...

Conflicts:
	drivers/media/rc/rc-main.c

1 files changed, 33 insertions, 0 deletions

diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 387dd4599344..c1d7f27bd38f 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -2050,6 +2050,33 @@ static void wake_nocb_leader(struct rcu_data *rdp, bool force)
 }
 
 /*
+ * Does the specified CPU need an RCU callback for the specified flavor
+ * of rcu_barrier()?
+ */
+static bool rcu_nocb_cpu_needs_barrier(struct rcu_state *rsp, int cpu)
+{
+	struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
+	struct rcu_head *rhp;
+
+	/* No-CBs CPUs might have callbacks on any of three lists. */
+	rhp = ACCESS_ONCE(rdp->nocb_head);
+	if (!rhp)
+		rhp = ACCESS_ONCE(rdp->nocb_gp_head);
+	if (!rhp)
+		rhp = ACCESS_ONCE(rdp->nocb_follower_head);
+
+	/* Having no rcuo kthread but CBs after scheduler starts is bad! */
+	if (!ACCESS_ONCE(rdp->nocb_kthread) && rhp) {
+		/* RCU callback enqueued before CPU first came online??? */
+		pr_err("RCU: Never-onlined no-CBs CPU %d has CB %p\n",
+		       cpu, rhp->func);
+		WARN_ON_ONCE(1);
+	}
+
+	return !!rhp;
+}
+
+/*
  * Enqueue the specified string of rcu_head structures onto the specified
  * CPU's no-CBs lists.  The CPU is specified by rdp, the head of the
  * string by rhp, and the tail of the string by rhtp.  The non-lazy/lazy
@@ -2642,6 +2669,12 @@ static bool init_nocb_callback_list(struct rcu_data *rdp)
 
 #else /* #ifdef CONFIG_RCU_NOCB_CPU */
 
+static bool rcu_nocb_cpu_needs_barrier(struct rcu_state *rsp, int cpu)
+{
+	WARN_ON_ONCE(1); /* Should be dead code. */
+	return false;
+}
+
 static void rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp)
 {
 }