Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull IRQ changes from Ingo Molnar:
 "The biggest change this cycle are the softirq/hardirq stack
  interaction and nesting fixes, cleanups and reorganizations from
  Frederic.  This is the longer followup story to the softirq nesting
  fix that is already upstream (commit ded797547548: "irq: Force hardirq
  exit's softirq processing on its own stack")"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: bcm2835: Convert to use IRQCHIP_DECLARE macro
  powerpc: Tell about irq stack coverage
  x86: Tell about irq stack coverage
  irq: Optimize softirq stack selection in irq exit
  irq: Justify the various softirq stack choices
  irq: Improve a bit softirq debugging
  irq: Optimize call to softirq on hardirq exit
  irq: Consolidate do_softirq() arch overriden implementations
  x86/irq: Correct comment about i8259 initialization

1 files changed, 21 insertions, 31 deletions

diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index 8ac2097f13d..bb27a262c44 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -157,39 +157,29 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 /*
  * Switch to the asynchronous interrupt stack for softirq execution.
  */
-asmlinkage void do_softirq(void)
+void do_softirq_own_stack(void)
 {
-	unsigned long flags, old, new;
-
-	if (in_interrupt())
-		return;
-
-	local_irq_save(flags);
-
-	if (local_softirq_pending()) {
-		/* Get current stack pointer. */
-		asm volatile("la %0,0(15)" : "=a" (old));
-		/* Check against async. stack address range. */
-		new = S390_lowcore.async_stack;
-		if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
-			/* Need to switch to the async. stack. */
-			new -= STACK_FRAME_OVERHEAD;
-			((struct stack_frame *) new)->back_chain = old;
-
-			asm volatile("   la    15,0(%0)\n"
-				     "   basr  14,%2\n"
-				     "   la    15,0(%1)\n"
-				     : : "a" (new), "a" (old),
-				         "a" (__do_softirq)
-				     : "0", "1", "2", "3", "4", "5", "14",
-				       "cc", "memory" );
-		} else {
-			/* We are already on the async stack. */
-			__do_softirq();
-		}
+	unsigned long old, new;
+
+	/* Get current stack pointer. */
+	asm volatile("la %0,0(15)" : "=a" (old));
+	/* Check against async. stack address range. */
+	new = S390_lowcore.async_stack;
+	if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
+		/* Need to switch to the async. stack. */
+		new -= STACK_FRAME_OVERHEAD;
+		((struct stack_frame *) new)->back_chain = old;
+		asm volatile("   la    15,0(%0)\n"
+			     "   basr  14,%2\n"
+			     "   la    15,0(%1)\n"
+			     : : "a" (new), "a" (old),
+			         "a" (__do_softirq)
+			     : "0", "1", "2", "3", "4", "5", "14",
+			       "cc", "memory" );
+	} else {
+		/* We are already on the async stack. */
+		__do_softirq();
 	}
-
-	local_irq_restore(flags);
 }
 
 /*