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026f37b031
Now that the Spinlock code is not dependent on architectural specific code anymore, we can move it back to the Locking folder. This also means that the Spinlock implemenation is now used for the aarch64 kernel.
67 lines
1.8 KiB
C++
67 lines
1.8 KiB
C++
/*
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* Copyright (c) 2020-2022, Andreas Kling <kling@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <Kernel/Locking/Spinlock.h>
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namespace Kernel {
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InterruptsState Spinlock::lock()
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{
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InterruptsState previous_interrupts_state = processor_interrupts_state();
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Processor::enter_critical();
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Processor::disable_interrupts();
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while (m_lock.exchange(1, AK::memory_order_acquire) != 0)
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Processor::wait_check();
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track_lock_acquire(m_rank);
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return previous_interrupts_state;
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}
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void Spinlock::unlock(InterruptsState previous_interrupts_state)
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{
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VERIFY(is_locked());
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track_lock_release(m_rank);
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m_lock.store(0, AK::memory_order_release);
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Processor::leave_critical();
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restore_processor_interrupts_state(previous_interrupts_state);
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}
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InterruptsState RecursiveSpinlock::lock()
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{
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InterruptsState previous_interrupts_state = processor_interrupts_state();
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Processor::disable_interrupts();
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Processor::enter_critical();
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auto& proc = Processor::current();
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FlatPtr cpu = FlatPtr(&proc);
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FlatPtr expected = 0;
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while (!m_lock.compare_exchange_strong(expected, cpu, AK::memory_order_acq_rel)) {
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if (expected == cpu)
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break;
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Processor::wait_check();
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expected = 0;
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}
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if (m_recursions == 0)
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track_lock_acquire(m_rank);
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m_recursions++;
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return previous_interrupts_state;
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}
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void RecursiveSpinlock::unlock(InterruptsState previous_interrupts_state)
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{
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VERIFY_INTERRUPTS_DISABLED();
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VERIFY(m_recursions > 0);
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VERIFY(m_lock.load(AK::memory_order_relaxed) == FlatPtr(&Processor::current()));
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if (--m_recursions == 0) {
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track_lock_release(m_rank);
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m_lock.store(0, AK::memory_order_release);
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}
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Processor::leave_critical();
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restore_processor_interrupts_state(previous_interrupts_state);
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}
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}
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