SMP: Implement enter/leave_critical_section

include/nuttx/irq.h

@@ -40,8 +40,11 @@
  * Included Files
  ****************************************************************************/
 
+#include <nuttx/config.h>
+
 #ifndef __ASSEMBLY__
 # include <assert.h>
+# include <arch/irq.h>
 #endif
 
 /****************************************************************************
@@ -97,6 +100,43 @@ extern "C"
 
 int irq_attach(int irq, xcpt_t isr);
 
+/****************************************************************************
+ * Name: enter_critical_section
+ *
+ * Description:
+ *   If SMP is enabled:
+ *     Take the CPU IRQ lock and disable interrupts on all CPUs.  A thread-
+ *     specific counter is increment to indicate that the thread has IRQs
+ *     disabled and to support nested calls to enter_critical_section().
+ *   If SMP is not enabled:
+ *     This function is equivalent to irqsave().
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_SMP
+irqstate_t enter_critical_section(void);
+#else
+#  define enter_critical_section(f) irqsave(f)
+#endif
+
+/****************************************************************************
+ * Name: leave_critical_section
+ *
+ * Description:
+ *   If SMP is enabled:
+ *     Decrement the IRQ lock count and if it decrements to zero then release
+ *     the spinlock.
+ *   If SMP is not enabled:
+ *     This function is equivalent to irqrestore().
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_SMP
+void leave_critical_section(irqstate_t flags);
+#else
+#  define leave_critical_section(f) irqrestore(f)
+#endif
+
 #undef EXTERN
 #ifdef __cplusplus
 }

include/nuttx/sched.h

@@ -560,6 +560,9 @@ struct tcb_s
 #endif
   uint16_t flags;                        /* Misc. general status flags          */
   int16_t  lockcount;                    /* 0=preemptable (not-locked)          */
+#ifdef CONFIG_SMP
+  int16_t  irqcount;                     /* 0=interrupts enabled                */
+#endif
 
 #if CONFIG_RR_INTERVAL > 0 || defined(CONFIG_SCHED_SPORADIC)
   int32_t  timeslice;                    /* RR timeslice OR Sporadic budget     */

include/nuttx/spinlock.h

@@ -103,7 +103,7 @@ spinlock_t up_testset(volatile FAR spinlock_t *lock);
  * Name: spin_initialize
  *
  * Description:
- *   Initialize a spinlock object to its initial, unlocked state.
+ *   Initialize a non-reentrant spinlock object to its initial, unlocked state.
  *
  * Input Parameters:
  *   lock - A reference to the spinlock object to be initialized.
@@ -113,7 +113,24 @@ spinlock_t up_testset(volatile FAR spinlock_t *lock);
  *
  ****************************************************************************/
 
-void spin_initialize(FAR struct spinlock_s *lock);
+/* void spin_initialize(FAR spinlock_t *lock); */
+#define spin_initialize(i) do { (l) = SPI_UNLOCKED; } while (0)
+
+/****************************************************************************
+ * Name: spin_initializer
+ *
+ * Description:
+ *   Initialize a re-entrant spinlock object to its initial, unlocked state.
+ *
+ * Input Parameters:
+ *   lock - A reference to the spinlock object to be initialized.
+ *
+ * Returned Value:
+ *   None.
+ *
+ ****************************************************************************/
+
+void spin_initializer(FAR struct spinlock_s *lock);
 
 /****************************************************************************
  * Name: spin_lock