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

[platform/adaptation/renesas_rcar/renesas_kernel.git] / kernel / softirq.c

diff --git a/kernel/softirq.c b/kernel/softirq.c
index dcab1d3..b249883 100644 (file)
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -29,7 +29,6 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/irq.h>
 
-#include <asm/irq.h>
 /*
    - No shared variables, all the data are CPU local.
    - If a softirq needs serialization, let it serialize itself
@@ -134,7 +133,6 @@ EXPORT_SYMBOL(local_bh_disable);
 
 static void __local_bh_enable(unsigned int cnt)
 {
-       WARN_ON_ONCE(in_irq());
        WARN_ON_ONCE(!irqs_disabled());
 
        if (softirq_count() == cnt)
@@ -149,6 +147,7 @@ static void __local_bh_enable(unsigned int cnt)
  */
 void _local_bh_enable(void)
 {
+       WARN_ON_ONCE(in_irq());
        __local_bh_enable(SOFTIRQ_DISABLE_OFFSET);
 }
 
@@ -171,8 +170,13 @@ static inline void _local_bh_enable_ip(unsigned long ip)
         */
        preempt_count_sub(SOFTIRQ_DISABLE_OFFSET - 1);
 
-       if (unlikely(!in_interrupt() && local_softirq_pending()))
+       if (unlikely(!in_interrupt() && local_softirq_pending())) {
+               /*
+                * Run softirq if any pending. And do it in its own stack
+                * as we may be calling this deep in a task call stack already.
+                */
                do_softirq();
+       }
 
        preempt_count_dec();
 #ifdef CONFIG_TRACE_IRQFLAGS
@@ -280,10 +284,11 @@ restart:
 
        account_irq_exit_time(current);
        __local_bh_enable(SOFTIRQ_OFFSET);
+       WARN_ON_ONCE(in_interrupt());
        tsk_restore_flags(current, old_flags, PF_MEMALLOC);
 }
 
-#ifndef __ARCH_HAS_DO_SOFTIRQ
+
 
 asmlinkage void do_softirq(void)
 {
@@ -298,13 +303,11 @@ asmlinkage void do_softirq(void)
        pending = local_softirq_pending();
 
        if (pending)
-               __do_softirq();
+               do_softirq_own_stack();
 
        local_irq_restore(flags);
 }
 
-#endif
-
 /*
  * Enter an interrupt context.
  */
@@ -329,15 +332,21 @@ void irq_enter(void)
 static inline void invoke_softirq(void)
 {
        if (!force_irqthreads) {
+#ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
                /*
                 * We can safely execute softirq on the current stack if
                 * it is the irq stack, because it should be near empty
-                * at this stage. But we have no way to know if the arch
-                * calls irq_exit() on the irq stack. So call softirq
-                * in its own stack to prevent from any overrun on top
-                * of a potentially deep task stack.
+                * at this stage.
                 */
-               do_softirq();
+               __do_softirq();
+#else
+               /*
+                * Otherwise, irq_exit() is called on the task stack that can
+                * be potentially deep already. So call softirq in its own stack
+                * to prevent from any overrun.
+                */
+               do_softirq_own_stack();
+#endif
        } else {
                wakeup_softirqd();
        }
@@ -771,6 +780,10 @@ static void run_ksoftirqd(unsigned int cpu)
 {
        local_irq_disable();
        if (local_softirq_pending()) {
+               /*
+                * We can safely run softirq on inline stack, as we are not deep
+                * in the task stack here.
+                */
                __do_softirq();
                rcu_note_context_switch(cpu);
                local_irq_enable();