Changes in kernel/generic/src/synch/spinlock.c [95d45482:4777e02] in mainline

File:

• kernel/generic/src/synch/spinlock.c (modified) (10 diffs)

kernel/generic/src/synch/spinlock.c

@@ -1 +1 @@
 /*
  * Copyright (c) 2001-2004 Jakub Jermar
+ * Copyright (c) 2023 Jiří Zárevúcky
  * All rights reserved.
  *
@@ -36 +37 @@
  */
 
+#ifdef CONFIG_SMP
+
+#include <arch/asm.h>
 #include <synch/spinlock.h>
 #include <atomic.h>
@@ -46 +50 @@
 #include <stacktrace.h>
 #include <cpu.h>
-
-#ifdef CONFIG_SMP
 
 /** Initialize spinlock
@@ -62 +64 @@
 }
 
-#ifdef CONFIG_DEBUG_SPINLOCK
-
 /** Lock spinlock
- *
- * Lock spinlock.
- * This version has limitted ability to report
- * possible occurence of deadlock.
  *
  * @param lock Pointer to spinlock_t structure.
  *
  */
-void spinlock_lock_debug(spinlock_t *lock)
+void spinlock_lock(spinlock_t *lock)
 {
+        preemption_disable();
+
+        bool deadlock_reported = false;
         size_t i = 0;
-        bool deadlock_reported = false;
 
-        preemption_disable();
         while (atomic_flag_test_and_set_explicit(&lock->flag, memory_order_acquire)) {
+                cpu_spin_hint();
+
+#ifdef CONFIG_DEBUG_SPINLOCK
                 /*
                  * We need to be careful about particular locks
@@ -111 +111 @@
                         deadlock_reported = true;
                 }
+#endif
         }
+
+        /* Avoid compiler warning with debug disabled. */
+        (void) i;
 
         if (deadlock_reported)
@@ -119 +123 @@
 /** Unlock spinlock
  *
- * Unlock spinlock.
- *
  * @param sl Pointer to spinlock_t structure.
  */
-void spinlock_unlock_debug(spinlock_t *lock)
+void spinlock_unlock(spinlock_t *lock)
 {
+#ifdef CONFIG_DEBUG_SPINLOCK
         ASSERT_SPINLOCK(spinlock_locked(lock), lock);
+#endif
 
         atomic_flag_clear_explicit(&lock->flag, memory_order_release);
@@ -131 +135 @@
 }
 
-#endif
-
-/** Lock spinlock conditionally
- *
+/**
  * Lock spinlock conditionally. If the spinlock is not available
  * at the moment, signal failure.
@@ -140 +141 @@
  * @param lock Pointer to spinlock_t structure.
  *
- * @return Zero on failure, non-zero otherwise.
+ * @return true on success.
  *
  */
@@ -146 +147 @@
 {
         preemption_disable();
+
         bool ret = !atomic_flag_test_and_set_explicit(&lock->flag, memory_order_acquire);
 
@@ -172 +174 @@
 }
 
-#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, disables interrupts before 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.
- *
- */
-bool irq_spinlock_trylock(irq_spinlock_t *lock)
-{
-        ASSERT_IRQ_SPINLOCK(interrupts_disabled(), lock);
-        bool ret = spinlock_trylock(&(lock->lock));
-
-        ASSERT_IRQ_SPINLOCK((!ret) || (!lock->guard), lock);
-        return ret;
-}
-
-/** 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));
-}
-
-/** Find out whether the IRQ spinlock is currently locked.
- *
- * @param lock          IRQ spinlock.
- * @return              True if the IRQ spinlock is locked, false otherwise.
- */
-bool irq_spinlock_locked(irq_spinlock_t *ilock)
-{
-        return spinlock_locked(&ilock->lock);
-}
+#endif  /* CONFIG_SMP */
 
 /** @}