From 8439296a50f69d95768eb232e3ad5f4b8d674ab9 Mon Sep 17 00:00:00 2001
From: hujun5 <hujun5@xiaomi.com>
Date: Wed, 20 Dec 2023 20:09:51 +0800
Subject: [PATCH] irq: inline restore_critical_section

reason:
In the SMP, when a context switch occurs, restore_critical_section is executed.
In order to reduce the time taken for context switching,
we inline the restore_critical_section function.
Given that restore_critical_section is small in size
and is called from only one location, inlining it does not increase the size of the image.

Signed-off-by: hujun5 <hujun5@xiaomi.com>
---
 include/nuttx/irq.h      | 14 ++++++++++++-
 sched/irq/irq_csection.c | 43 ----------------------------------------
 sched/sched/sched.h      | 10 ++++++++++
 3 files changed, 23 insertions(+), 44 deletions(-)

diff --git a/include/nuttx/irq.h b/include/nuttx/irq.h
index b281eb9a41..ed89b46c95 100644
--- a/include/nuttx/irq.h
+++ b/include/nuttx/irq.h
@@ -312,7 +312,19 @@ void leave_critical_section(irqstate_t flags) noinstrument_function;
  ****************************************************************************/
 
 #ifdef CONFIG_SMP
-void restore_critical_section(void);
+#  define restore_critical_section() \
+   do { \
+       FAR struct tcb_s *tcb; \
+       int me = this_cpu(); \
+       tcb = current_task(me); \
+       if (tcb->irqcount <= 0) \
+         {\
+           if ((g_cpu_irqset & (1 << me)) != 0) \
+             { \
+               cpu_irqlock_clear(); \
+             } \
+         } \
+    } while (0)
 #else
 #  define restore_critical_section()
 #endif
diff --git a/sched/irq/irq_csection.c b/sched/irq/irq_csection.c
index 7909f58cd7..fb23acab7b 100644
--- a/sched/irq/irq_csection.c
+++ b/sched/irq/irq_csection.c
@@ -644,47 +644,4 @@ inline_function void leave_critical_section_nonirq(irqstate_t flags)
   up_irq_restore(flags);
 }
 #endif
-
-/****************************************************************************
- * Name: restore_critical_section
- *
- * Description:
- *   Restore the critical_section
- *
- * Input Parameters:
- *   None
- *
- * Returned Value:
- *   None
- *
- ****************************************************************************/
-
-#ifdef CONFIG_SMP
-void restore_critical_section(void)
-{
-  /* NOTE: The following logic for adjusting global IRQ controls were
-   * derived from nxsched_add_readytorun() and sched_removedreadytorun()
-   * Here, we only handles clearing logic to defer unlocking IRQ lock
-   * followed by context switching.
-   */
-
-  FAR struct tcb_s *tcb;
-  int me = this_cpu();
-
-  /* Adjust global IRQ controls.  If irqcount is greater than zero,
-   * then this task/this CPU holds the IRQ lock
-   */
-
-  tcb = current_task(me);
-  DEBUGASSERT(g_cpu_nestcount[me] <= 0);
-  if (tcb->irqcount <= 0)
-    {
-      if ((g_cpu_irqset & (1 << me)) != 0)
-        {
-          cpu_irqlock_clear();
-        }
-    }
-}
-#endif /* CONFIG_SMP */
-
 #endif /* CONFIG_IRQCOUNT */
diff --git a/sched/sched/sched.h b/sched/sched/sched.h
index 660a997fc6..d255d04bdf 100644
--- a/sched/sched/sched.h
+++ b/sched/sched/sched.h
@@ -291,6 +291,16 @@ extern volatile clock_t g_cpuload_total;
 
 extern volatile cpu_set_t g_cpu_lockset;
 
+/* This is the spinlock that enforces critical sections when interrupts are
+ * disabled.
+ */
+
+extern volatile spinlock_t g_cpu_irqlock;
+
+/* Used to keep track of which CPU(s) hold the IRQ lock. */
+
+extern volatile cpu_set_t g_cpu_irqset;
+
 /* Used to lock tasklist to prevent from concurrent access */
 
 extern volatile spinlock_t g_cpu_tasklistlock;