[patch 13/19] softirq: Move various protections into inline helpers

[Thomas Gleixner]

To allow reuse of the bulk of softirq processing code for RT and to avoid
#ifdeffery all over the place, split protections for various code sections
out into inline helpers so the RT variant can just replace them in one go.

Signed-off-by: Thomas Gleixner <t...@linutronix.de>
---
 kernel/softirq.c |   53 ++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 44 insertions(+), 9 deletions(-)

--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -204,6 +204,42 @@ void __local_bh_enable_ip(unsigned long
 }
 EXPORT_SYMBOL(__local_bh_enable_ip);
 
+static inline void local_bh_disable_irq_enter(void)
+{
+       local_bh_disable();
+}
+
+static inline void local_bh_enable_irq_enter(void)
+{
+       _local_bh_enable();
+}
+
+static inline void softirq_handle_begin(void)
+{
+       __local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET);
+}
+
+static inline void softirq_handle_end(void)
+{
+       __local_bh_enable(SOFTIRQ_OFFSET);
+       WARN_ON_ONCE(in_interrupt());
+}
+
+static inline void ksoftirqd_run_begin(void)
+{
+       local_irq_disable();
+}
+
+static inline void ksoftirqd_run_end(void)
+{
+       local_irq_enable();
+}
+
+static inline bool should_wake_ksoftirqd(void)
+{
+       return true;
+}
+
 static inline void invoke_softirq(void)
 {
        if (ksoftirqd_running(local_softirq_pending()))
@@ -317,7 +353,7 @@ asmlinkage __visible void __softirq_entr
        pending = local_softirq_pending();
        account_irq_enter_time(current);
 
-       __local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET);
+       softirq_handle_begin();
        in_hardirq = lockdep_softirq_start();
 
 restart:
@@ -367,8 +403,7 @@ asmlinkage __visible void __softirq_entr
 
        lockdep_softirq_end(in_hardirq);
        account_irq_exit_time(current);
-       __local_bh_enable(SOFTIRQ_OFFSET);
-       WARN_ON_ONCE(in_interrupt());
+       softirq_handle_end();
        current_restore_flags(old_flags, PF_MEMALLOC);
 }
 
@@ -382,9 +417,9 @@ void irq_enter_rcu(void)
                 * Prevent raise_softirq from needlessly waking up ksoftirqd
                 * here, as softirq will be serviced on return from interrupt.
                 */
-               local_bh_disable();
+               local_bh_disable_irq_enter();
                tick_irq_enter();
-               _local_bh_enable();
+               local_bh_enable_irq_enter();
        }
        __irq_enter();
 }
@@ -467,7 +502,7 @@ inline void raise_softirq_irqoff(unsigne
         * Otherwise we wake up ksoftirqd to make sure we
         * schedule the softirq soon.
         */
-       if (!in_interrupt())
+       if (!in_interrupt() && should_wake_ksoftirqd())
                wakeup_softirqd();
 }
 
@@ -645,18 +680,18 @@ static int ksoftirqd_should_run(unsigned
 
 static void run_ksoftirqd(unsigned int cpu)
 {
-       local_irq_disable();
+       ksoftirqd_run_begin();
        if (local_softirq_pending()) {
                /*
                 * We can safely run softirq on inline stack, as we are not deep
                 * in the task stack here.
                 */
                __do_softirq();
-               local_irq_enable();
+               ksoftirqd_run_end();
                cond_resched();
                return;
        }
-       local_irq_enable();
+       ksoftirqd_run_end();
 }
 
 #ifdef CONFIG_HOTPLUG_CPU