sched/wdog: use small lock to protect g_wdactivelist

reason:
We would like to replace the critical section with a small lock.

Signed-off-by: hujun5 <hujun5@xiaomi.com>

drivers/note/note_driver.c

@@ -1393,10 +1393,12 @@ void sched_note_irqhandler(int irq, FAR void *handler, bool enter)
 void sched_note_wdog(uint8_t event, FAR void *handler, FAR const void *arg)
 {
   FAR struct note_driver_s **driver;
+  irqstate_t flags;
   struct note_wdog_s note;
   bool formatted = false;
   FAR struct tcb_s *tcb = this_task();
 
+  flags = enter_critical_section_wo_note();
   for (driver = g_note_drivers; *driver; driver++)
     {
       if (note_wdog(*driver, event, handler, arg))
@@ -1421,6 +1423,8 @@ void sched_note_wdog(uint8_t event, FAR void *handler, FAR const void *arg)
 
       note_add(*driver, &note, sizeof(note));
     }
+
+  leave_critical_section_wo_note(flags);
 }
 #endif
 

sched/wdog/wd_cancel.c

@@ -38,6 +38,8 @@
 #include "sched/sched.h"
 #include "wdog/wdog.h"
 
+spinlock_t g_wdog_spinlock = SP_UNLOCKED;
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -60,15 +62,10 @@
 
 int wd_cancel(FAR struct wdog_s *wdog)
 {
-  irqstate_t flags;
   int ret;
 
-  flags = enter_critical_section();
-
   ret = wd_cancel_irq(wdog);
 
-  leave_critical_section(flags);
-
   return ret;
 }
 
@@ -91,12 +88,16 @@ int wd_cancel(FAR struct wdog_s *wdog)
 
 int wd_cancel_irq(FAR struct wdog_s *wdog)
 {
+  irqstate_t flags;
   bool head;
 
+  flags = spin_lock_irqsave(&g_wdog_spinlock);
+
   /* Make sure that the watchdog is valid and still active. */
 
   if (wdog == NULL || !WDOG_ISACTIVE(wdog))
     {
+      spin_unlock_irqrestore(&g_wdog_spinlock, flags);
       return -EINVAL;
     }
 
@@ -116,6 +117,7 @@ int wd_cancel_irq(FAR struct wdog_s *wdog)
   /* Mark the watchdog inactive */
 
   wdog->func = NULL;
+  spin_unlock_irqrestore(&g_wdog_spinlock, flags);
 
   if (head)
     {

sched/wdog/wd_start.c

@@ -112,10 +112,11 @@ static unsigned int g_wdtimernested;
 static inline_function void wd_expiration(clock_t ticks)
 {
   FAR struct wdog_s *wdog;
+  wdparm_t arg;
   irqstate_t flags;
   wdentry_t func;
 
-  flags = enter_critical_section();
+  flags = spin_lock_irqsave(&g_wdog_spinlock);
 
 #ifdef CONFIG_SCHED_TICKLESS
   /* Increment the nested watchdog timer count to handle cases where wd_start
@@ -147,12 +148,17 @@ static inline_function void wd_expiration(clock_t ticks)
       /* Indicate that the watchdog is no longer active. */
 
       func = wdog->func;
+      arg = wdog->arg;
       wdog->func = NULL;
 
       /* Execute the watchdog function */
 
       up_setpicbase(wdog->picbase);
-      CALL_FUNC(func, wdog->arg);
+      spin_unlock_irqrestore(&g_wdog_spinlock, flags);
+
+      CALL_FUNC(func, arg);
+
+      flags = spin_lock_irqsave(&g_wdog_spinlock);
     }
 
 #ifdef CONFIG_SCHED_TICKLESS
@@ -161,7 +167,7 @@ static inline_function void wd_expiration(clock_t ticks)
   g_wdtimernested--;
 #endif
 
-  leave_critical_section(flags);
+  spin_unlock_irqrestore(&g_wdog_spinlock, flags);
 }
 
 /****************************************************************************
@@ -293,7 +299,7 @@ int wd_start_abstick(FAR struct wdog_s *wdog, clock_t ticks,
    * the critical section is established.
    */
 
-  flags = enter_critical_section();
+  flags = spin_lock_irqsave(&g_wdog_spinlock);
 #ifdef CONFIG_SCHED_TICKLESS
   /* We need to reassess timer if the watchdog list head has changed. */
 
@@ -314,8 +320,13 @@ int wd_start_abstick(FAR struct wdog_s *wdog, clock_t ticks,
        * then this will pick that new delay.
        */
 
+      spin_unlock_irqrestore(&g_wdog_spinlock, flags);
       nxsched_reassess_timer();
     }
+  else
+    {
+      spin_unlock_irqrestore(&g_wdog_spinlock, flags);
+    }
 #else
   UNUSED(reassess);
 
@@ -328,8 +339,8 @@ int wd_start_abstick(FAR struct wdog_s *wdog, clock_t ticks,
     }
 
   wd_insert(wdog, ticks, wdentry, arg);
+  spin_unlock_irqrestore(&g_wdog_spinlock, flags);
 #endif
-  leave_critical_section(flags);
 
   sched_note_wdog(NOTE_WDOG_START, wdentry, (FAR void *)(uintptr_t)ticks);
   return OK;
@@ -425,13 +436,13 @@ clock_t wd_timer(clock_t ticks, bool noswitches)
       wd_expiration(ticks);
     }
 
-  flags = enter_critical_section();
+  flags = spin_lock_irqsave(&g_wdog_spinlock);
 
   /* Return the delay for the next watchdog to expire */
 
   if (list_is_empty(&g_wdactivelist))
     {
-      leave_critical_section(flags);
+      spin_unlock_irqrestore(&g_wdog_spinlock, flags);
       return 0;
     }
 
@@ -442,7 +453,7 @@ clock_t wd_timer(clock_t ticks, bool noswitches)
   wdog = list_first_entry(&g_wdactivelist, struct wdog_s, node);
   ret = wdog->expired - ticks;
 
-  leave_critical_section(flags);
+  spin_unlock_irqrestore(&g_wdog_spinlock, flags);
 
   /* Return the delay for the next watchdog to expire */
 

sched/wdog/wdog.h

@@ -37,6 +37,7 @@
 #include <nuttx/queue.h>
 #include <nuttx/wdog.h>
 #include <nuttx/list.h>
+#include <nuttx/spinlock_type.h>
 
 /****************************************************************************
  * Pre-processor Definitions
@@ -64,6 +65,7 @@ extern "C"
  */
 
 extern struct list_node g_wdactivelist;
+extern spinlock_t g_wdog_spinlock;
 
 /****************************************************************************
  * Public Function Prototypes