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Diffstat (limited to 'src/core/hle/kernel/k_address_arbiter.cpp')
| -rw-r--r-- | src/core/hle/kernel/k_address_arbiter.cpp | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/src/core/hle/kernel/k_address_arbiter.cpp b/src/core/hle/kernel/k_address_arbiter.cpp new file mode 100644 index 000000000..7018f56da --- /dev/null +++ b/src/core/hle/kernel/k_address_arbiter.cpp @@ -0,0 +1,341 @@ +// Copyright 2021 yuzu Emulator Project +// Licensed under GPLv2 or any later version +// Refer to the license.txt file included. + +#include "core/arm/exclusive_monitor.h" +#include "core/core.h" +#include "core/hle/kernel/k_address_arbiter.h" +#include "core/hle/kernel/k_scheduler.h" +#include "core/hle/kernel/k_scoped_scheduler_lock_and_sleep.h" +#include "core/hle/kernel/k_thread.h" +#include "core/hle/kernel/kernel.h" +#include "core/hle/kernel/svc_results.h" +#include "core/hle/kernel/time_manager.h" +#include "core/memory.h" + +namespace Kernel { + +KAddressArbiter::KAddressArbiter(Core::System& system_) + : system{system_}, kernel{system.Kernel()} {} +KAddressArbiter::~KAddressArbiter() = default; + +namespace { + +bool ReadFromUser(Core::System& system, s32* out, VAddr address) { + *out = system.Memory().Read32(address); + return true; +} + +bool DecrementIfLessThan(Core::System& system, s32* out, VAddr address, s32 value) { + auto& monitor = system.Monitor(); + const auto current_core = system.CurrentCoreIndex(); + + // TODO(bunnei): We should disable interrupts here via KScopedInterruptDisable. + // TODO(bunnei): We should call CanAccessAtomic(..) here. + + // Load the value from the address. + const s32 current_value = static_cast<s32>(monitor.ExclusiveRead32(current_core, address)); + + // Compare it to the desired one. + if (current_value < value) { + // If less than, we want to try to decrement. + const s32 decrement_value = current_value - 1; + + // Decrement and try to store. + if (!monitor.ExclusiveWrite32(current_core, address, static_cast<u32>(decrement_value))) { + // If we failed to store, try again. + DecrementIfLessThan(system, out, address, value); + } + } else { + // Otherwise, clear our exclusive hold and finish + monitor.ClearExclusive(); + } + + // We're done. + *out = current_value; + return true; +} + +bool UpdateIfEqual(Core::System& system, s32* out, VAddr address, s32 value, s32 new_value) { + auto& monitor = system.Monitor(); + const auto current_core = system.CurrentCoreIndex(); + + // TODO(bunnei): We should disable interrupts here via KScopedInterruptDisable. + // TODO(bunnei): We should call CanAccessAtomic(..) here. + + // Load the value from the address. + const s32 current_value = static_cast<s32>(monitor.ExclusiveRead32(current_core, address)); + + // Compare it to the desired one. + if (current_value == value) { + // If equal, we want to try to write the new value. + + // Try to store. + if (!monitor.ExclusiveWrite32(current_core, address, static_cast<u32>(new_value))) { + // If we failed to store, try again. + UpdateIfEqual(system, out, address, value, new_value); + } + } else { + // Otherwise, clear our exclusive hold and finish. + monitor.ClearExclusive(); + } + + // We're done. + *out = current_value; + return true; +} + +} // namespace + +ResultCode KAddressArbiter::Signal(VAddr addr, s32 count) { + // Perform signaling. + s32 num_waiters{}; + { + KScopedSchedulerLock sl(kernel); + + auto it = thread_tree.nfind_light({addr, -1}); + while ((it != thread_tree.end()) && (count <= 0 || num_waiters < count) && + (it->GetAddressArbiterKey() == addr)) { + KThread* target_thread = std::addressof(*it); + target_thread->SetSyncedObject(nullptr, RESULT_SUCCESS); + + ASSERT(target_thread->IsWaitingForAddressArbiter()); + target_thread->Wakeup(); + + it = thread_tree.erase(it); + target_thread->ClearAddressArbiter(); + ++num_waiters; + } + } + return RESULT_SUCCESS; +} + +ResultCode KAddressArbiter::SignalAndIncrementIfEqual(VAddr addr, s32 value, s32 count) { + // Perform signaling. + s32 num_waiters{}; + { + KScopedSchedulerLock sl(kernel); + + // Check the userspace value. + s32 user_value{}; + if (!UpdateIfEqual(system, &user_value, addr, value, value + 1)) { + LOG_ERROR(Kernel, "Invalid current memory!"); + return ResultInvalidCurrentMemory; + } + if (user_value != value) { + return ResultInvalidState; + } + + auto it = thread_tree.nfind_light({addr, -1}); + while ((it != thread_tree.end()) && (count <= 0 || num_waiters < count) && + (it->GetAddressArbiterKey() == addr)) { + KThread* target_thread = std::addressof(*it); + target_thread->SetSyncedObject(nullptr, RESULT_SUCCESS); + + ASSERT(target_thread->IsWaitingForAddressArbiter()); + target_thread->Wakeup(); + + it = thread_tree.erase(it); + target_thread->ClearAddressArbiter(); + ++num_waiters; + } + } + return RESULT_SUCCESS; +} + +ResultCode KAddressArbiter::SignalAndModifyByWaitingCountIfEqual(VAddr addr, s32 value, s32 count) { + // Perform signaling. + s32 num_waiters{}; + { + [[maybe_unused]] const KScopedSchedulerLock sl(kernel); + + auto it = thread_tree.nfind_light({addr, -1}); + // Determine the updated value. + s32 new_value{}; + if (count <= 0) { + if (it != thread_tree.end() && it->GetAddressArbiterKey() == addr) { + new_value = value - 2; + } else { + new_value = value + 1; + } + } else { + if (it != thread_tree.end() && it->GetAddressArbiterKey() == addr) { + auto tmp_it = it; + s32 tmp_num_waiters{}; + while (++tmp_it != thread_tree.end() && tmp_it->GetAddressArbiterKey() == addr) { + if (tmp_num_waiters++ >= count) { + break; + } + } + + if (tmp_num_waiters < count) { + new_value = value - 1; + } else { + new_value = value; + } + } else { + new_value = value + 1; + } + } + + // Check the userspace value. + s32 user_value{}; + bool succeeded{}; + if (value != new_value) { + succeeded = UpdateIfEqual(system, &user_value, addr, value, new_value); + } else { + succeeded = ReadFromUser(system, &user_value, addr); + } + + if (!succeeded) { + LOG_ERROR(Kernel, "Invalid current memory!"); + return ResultInvalidCurrentMemory; + } + if (user_value != value) { + return ResultInvalidState; + } + + while ((it != thread_tree.end()) && (count <= 0 || num_waiters < count) && + (it->GetAddressArbiterKey() == addr)) { + KThread* target_thread = std::addressof(*it); + target_thread->SetSyncedObject(nullptr, RESULT_SUCCESS); + + ASSERT(target_thread->IsWaitingForAddressArbiter()); + target_thread->Wakeup(); + + it = thread_tree.erase(it); + target_thread->ClearAddressArbiter(); + ++num_waiters; + } + } + return RESULT_SUCCESS; +} + +ResultCode KAddressArbiter::WaitIfLessThan(VAddr addr, s32 value, bool decrement, s64 timeout) { + // Prepare to wait. + KThread* cur_thread = kernel.CurrentScheduler()->GetCurrentThread(); + + { + KScopedSchedulerLockAndSleep slp{kernel, cur_thread, timeout}; + + // Check that the thread isn't terminating. + if (cur_thread->IsTerminationRequested()) { + slp.CancelSleep(); + return ResultTerminationRequested; + } + + // Set the synced object. + cur_thread->SetSyncedObject(nullptr, ResultTimedOut); + + // Read the value from userspace. + s32 user_value{}; + bool succeeded{}; + if (decrement) { + succeeded = DecrementIfLessThan(system, &user_value, addr, value); + } else { + succeeded = ReadFromUser(system, &user_value, addr); + } + + if (!succeeded) { + slp.CancelSleep(); + return ResultInvalidCurrentMemory; + } + + // Check that the value is less than the specified one. + if (user_value >= value) { + slp.CancelSleep(); + return ResultInvalidState; + } + + // Check that the timeout is non-zero. + if (timeout == 0) { + slp.CancelSleep(); + return ResultTimedOut; + } + + // Set the arbiter. + cur_thread->SetAddressArbiter(&thread_tree, addr); + thread_tree.insert(*cur_thread); + cur_thread->SetState(ThreadState::Waiting); + cur_thread->SetWaitReasonForDebugging(ThreadWaitReasonForDebugging::Arbitration); + } + + // Cancel the timer wait. + kernel.TimeManager().UnscheduleTimeEvent(cur_thread); + + // Remove from the address arbiter. + { + KScopedSchedulerLock sl(kernel); + + if (cur_thread->IsWaitingForAddressArbiter()) { + thread_tree.erase(thread_tree.iterator_to(*cur_thread)); + cur_thread->ClearAddressArbiter(); + } + } + + // Get the result. + KSynchronizationObject* dummy{}; + return cur_thread->GetWaitResult(&dummy); +} + +ResultCode KAddressArbiter::WaitIfEqual(VAddr addr, s32 value, s64 timeout) { + // Prepare to wait. + KThread* cur_thread = kernel.CurrentScheduler()->GetCurrentThread(); + + { + KScopedSchedulerLockAndSleep slp{kernel, cur_thread, timeout}; + + // Check that the thread isn't terminating. + if (cur_thread->IsTerminationRequested()) { + slp.CancelSleep(); + return ResultTerminationRequested; + } + + // Set the synced object. + cur_thread->SetSyncedObject(nullptr, ResultTimedOut); + + // Read the value from userspace. + s32 user_value{}; + if (!ReadFromUser(system, &user_value, addr)) { + slp.CancelSleep(); + return ResultInvalidCurrentMemory; + } + + // Check that the value is equal. + if (value != user_value) { + slp.CancelSleep(); + return ResultInvalidState; + } + + // Check that the timeout is non-zero. + if (timeout == 0) { + slp.CancelSleep(); + return ResultTimedOut; + } + + // Set the arbiter. + cur_thread->SetAddressArbiter(&thread_tree, addr); + thread_tree.insert(*cur_thread); + cur_thread->SetState(ThreadState::Waiting); + cur_thread->SetWaitReasonForDebugging(ThreadWaitReasonForDebugging::Arbitration); + } + + // Cancel the timer wait. + kernel.TimeManager().UnscheduleTimeEvent(cur_thread); + + // Remove from the address arbiter. + { + KScopedSchedulerLock sl(kernel); + + if (cur_thread->IsWaitingForAddressArbiter()) { + thread_tree.erase(thread_tree.iterator_to(*cur_thread)); + cur_thread->ClearAddressArbiter(); + } + } + + // Get the result. + KSynchronizationObject* dummy{}; + return cur_thread->GetWaitResult(&dummy); +} + +} // namespace Kernel |