diff options
Diffstat (limited to 'Kernel')
| -rw-r--r-- | Kernel/Arch/i386/CPU.cpp | 3 | ||||
| -rw-r--r-- | Kernel/Arch/i386/CPU.h | 31 | ||||
| -rw-r--r-- | Kernel/Thread.h | 4 |
3 files changed, 25 insertions, 13 deletions
diff --git a/Kernel/Arch/i386/CPU.cpp b/Kernel/Arch/i386/CPU.cpp index 67848f1422..0105b5e639 100644 --- a/Kernel/Arch/i386/CPU.cpp +++ b/Kernel/Arch/i386/CPU.cpp @@ -1291,6 +1291,7 @@ extern "C" void enter_thread_context(Thread* from_thread, Thread* to_thread) write_cr3(to_tss.cr3); to_thread->set_cpu(processor.id()); + processor.restore_in_critical(to_thread->saved_critical()); asm volatile("fxrstor %0" ::"m"(to_thread->fpu_state())); @@ -1308,6 +1309,7 @@ void Processor::switch_context(Thread*& from_thread, Thread*& to_thread) ASSERT(is_kernel_mode()); dbgln<CONTEXT_SWITCH_DEBUG>("switch_context --> switching out of: {} {}", VirtualAddress(from_thread), *from_thread); + from_thread->save_critical(m_in_critical); // Switch to new thread context, passing from_thread and to_thread // through to the new context using registers edx and eax @@ -1347,6 +1349,7 @@ void Processor::switch_context(Thread*& from_thread, Thread*& to_thread) [to_eip] "c" (to_thread->tss().eip), [from_thread] "d" (from_thread), [to_thread] "a" (to_thread) + : "memory" ); dbgln<CONTEXT_SWITCH_DEBUG>("switch_context <-- from {} {} to {} {}", VirtualAddress(from_thread), *from_thread, VirtualAddress(to_thread), *to_thread); diff --git a/Kernel/Arch/i386/CPU.h b/Kernel/Arch/i386/CPU.h index 0595912189..bdc75034dd 100644 --- a/Kernel/Arch/i386/CPU.h +++ b/Kernel/Arch/i386/CPU.h @@ -708,7 +708,7 @@ class Processor { u32 m_cpu; u32 m_in_irq; - u32 m_in_critical; + Atomic<u32, AK::MemoryOrder::memory_order_relaxed> m_in_critical; TSS32 m_tss; static FPUState s_clean_fpu_state; @@ -876,15 +876,16 @@ public: { ASSERT(prev_irq <= m_in_irq); if (!prev_irq) { - if (m_in_critical == 0) { - auto prev_critical = m_in_critical++; + u32 prev_critical = 0; + if (m_in_critical.compare_exchange_strong(prev_critical, 1)) { m_in_irq = prev_irq; deferred_call_execute_pending(); - ASSERT(m_in_critical == prev_critical + 1); - m_in_critical = prev_critical; - } - if (!m_in_critical) + auto prev_raised = m_in_critical.exchange(prev_critical); + ASSERT(prev_raised == prev_critical + 1); + check_invoke_scheduler(); + } else if (prev_critical == 0) { check_invoke_scheduler(); + } } else { m_in_irq = prev_irq; } @@ -895,11 +896,16 @@ public: return m_in_irq; } + ALWAYS_INLINE void restore_in_critical(u32 critical) + { + m_in_critical = critical; + } + ALWAYS_INLINE void enter_critical(u32& prev_flags) { - m_in_critical++; prev_flags = cpu_flags(); cli(); + m_in_critical++; } ALWAYS_INLINE void leave_critical(u32 prev_flags) @@ -925,9 +931,8 @@ public: ALWAYS_INLINE u32 clear_critical(u32& prev_flags, bool enable_interrupts) { - u32 prev_crit = m_in_critical; - m_in_critical = 0; prev_flags = cpu_flags(); + u32 prev_crit = m_in_critical.exchange(0, AK::MemoryOrder::memory_order_acquire); if (!m_in_irq) check_invoke_scheduler(); if (enable_interrupts) @@ -937,15 +942,15 @@ public: ALWAYS_INLINE void restore_critical(u32 prev_crit, u32 prev_flags) { - ASSERT(m_in_critical == 0); - m_in_critical = prev_crit; + m_in_critical.store(prev_crit, AK::MemoryOrder::memory_order_release); + ASSERT(!prev_crit || !(prev_flags & 0x200)); if (prev_flags & 0x200) sti(); else cli(); } - ALWAYS_INLINE u32& in_critical() { return m_in_critical; } + ALWAYS_INLINE u32 in_critical() { return m_in_critical.load(); } ALWAYS_INLINE const FPUState& clean_fpu_state() const { diff --git a/Kernel/Thread.h b/Kernel/Thread.h index 52fa204e6d..4208f245fd 100644 --- a/Kernel/Thread.h +++ b/Kernel/Thread.h @@ -1065,6 +1065,9 @@ public: m_is_active.store(active, AK::memory_order_release); } + u32 saved_critical() const { return m_saved_critical; } + void save_critical(u32 critical) { m_saved_critical = critical; } + [[nodiscard]] bool is_active() const { return m_is_active.load(AK::MemoryOrder::memory_order_acquire); @@ -1239,6 +1242,7 @@ private: ThreadID m_tid { -1 }; TSS32 m_tss; TrapFrame* m_current_trap { nullptr }; + u32 m_saved_critical { 1 }; Atomic<u32> m_cpu { 0 }; u32 m_cpu_affinity { THREAD_AFFINITY_DEFAULT }; u32 m_ticks_left { 0 }; |