Changeset a9f1372 in mainline for kernel/generic/src/synch/spinlock.c

Timestamp:

2010-05-25T18:35:36Z (15 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

b7398c0

Parents:

0095368

Message:

Move the irq_spinlock code to spinlock.c for better debuggability.

File:

• kernel/generic/src/synch/spinlock.c (modified) (1 diff)

kernel/generic/src/synch/spinlock.c

@@ -169 +169 @@
 #endif
 
+/** Initialize interrupts-disabled spinlock
+ *
+ * @param lock IRQ spinlock to be initialized.
+ * @param name IRQ spinlock name.
+ *
+ */
+void irq_spinlock_initialize(irq_spinlock_t *lock, const char *name)
+{
+        spinlock_initialize(&(lock->lock), name);
+        lock->guard = false;
+        lock->ipl = 0;
+}
+
+/** Lock interrupts-disabled spinlock
+ *
+ * Lock a spinlock which requires disabled interrupts.
+ *
+ * @param lock    IRQ spinlock to be locked.
+ * @param irq_dis If true, interrupts are actually disabled
+ *                prior locking the spinlock. If false, interrupts
+ *                are expected to be already disabled.
+ *
+ */
+void irq_spinlock_lock(irq_spinlock_t *lock, bool irq_dis)
+{
+        if (irq_dis) {
+                ipl_t ipl = interrupts_disable();
+                spinlock_lock(&(lock->lock));
+                
+                lock->guard = true;
+                lock->ipl = ipl;
+        } else {
+                ASSERT_IRQ_SPINLOCK(interrupts_disabled(), lock);
+                
+                spinlock_lock(&(lock->lock));
+                ASSERT_IRQ_SPINLOCK(!lock->guard, lock);
+        }
+}
+
+/** Unlock interrupts-disabled spinlock
+ *
+ * Unlock a spinlock which requires disabled interrupts.
+ *
+ * @param lock    IRQ spinlock to be unlocked.
+ * @param irq_res If true, interrupts are restored to previously
+ *                saved interrupt level.
+ *
+ */
+void irq_spinlock_unlock(irq_spinlock_t *lock, bool irq_res)
+{
+        ASSERT_IRQ_SPINLOCK(interrupts_disabled(), lock);
+        
+        if (irq_res) {
+                ASSERT_IRQ_SPINLOCK(lock->guard, lock);
+                
+                lock->guard = false;
+                ipl_t ipl = lock->ipl;
+                
+                spinlock_unlock(&(lock->lock));
+                interrupts_restore(ipl);
+        } else {
+                ASSERT_IRQ_SPINLOCK(!lock->guard, lock);
+                spinlock_unlock(&(lock->lock));
+        }
+}
+
+/** Lock interrupts-disabled spinlock
+ *
+ * Lock an interrupts-disabled spinlock conditionally. If the
+ * spinlock is not available at the moment, signal failure.
+ * Interrupts are expected to be already disabled.
+ *
+ * @param lock IRQ spinlock to be locked conditionally.
+ *
+ * @return Zero on failure, non-zero otherwise.
+ *
+ */
+int irq_spinlock_trylock(irq_spinlock_t *lock)
+{
+        ASSERT_IRQ_SPINLOCK(interrupts_disabled(), lock);
+        int rc = spinlock_trylock(&(lock->lock));
+        
+        ASSERT_IRQ_SPINLOCK(!lock->guard, lock);
+        return rc;
+}
+
+/** Pass lock from one interrupts-disabled spinlock to another
+ *
+ * Pass lock from one IRQ spinlock to another IRQ spinlock
+ * without enabling interrupts during the process.
+ *
+ * The first IRQ spinlock is supposed to be locked.
+ *
+ * @param unlock IRQ spinlock to be unlocked.
+ * @param lock   IRQ spinlock to be locked.
+ *
+ */
+void irq_spinlock_pass(irq_spinlock_t *unlock, irq_spinlock_t *lock)
+{
+        ASSERT_IRQ_SPINLOCK(interrupts_disabled(), unlock);
+        
+        /* Pass guard from unlock to lock */
+        bool guard = unlock->guard;
+        ipl_t ipl = unlock->ipl;
+        unlock->guard = false;
+        
+        spinlock_unlock(&(unlock->lock));
+        spinlock_lock(&(lock->lock));
+        
+        ASSERT_IRQ_SPINLOCK(!lock->guard, lock);
+        
+        if (guard) {
+                lock->guard = true;
+                lock->ipl = ipl;
+        }
+}
+
+/** Hand-over-hand locking of interrupts-disabled spinlocks
+ *
+ * Implement hand-over-hand locking between two interrupts-disabled
+ * spinlocks without enabling interrupts during the process.
+ *
+ * The first IRQ spinlock is supposed to be locked.
+ *
+ * @param unlock IRQ spinlock to be unlocked.
+ * @param lock   IRQ spinlock to be locked.
+ *
+ */
+void irq_spinlock_exchange(irq_spinlock_t *unlock, irq_spinlock_t *lock)
+{
+        ASSERT_IRQ_SPINLOCK(interrupts_disabled(), unlock);
+        
+        spinlock_lock(&(lock->lock));
+        ASSERT_IRQ_SPINLOCK(!lock->guard, lock);
+        
+        /* Pass guard from unlock to lock */
+        if (unlock->guard) {
+                lock->guard = true;
+                lock->ipl = unlock->ipl;
+                unlock->guard = false;
+        }
+        
+        spinlock_unlock(&(unlock->lock));
+}
+
 /** @}
  */