1
0
Fork 0
mirror of https://github.com/Atmosphere-NX/Atmosphere.git synced 2024-11-08 21:21:48 +00:00
Atmosphere/libraries/libmesosphere/source/kern_k_address_arbiter.cpp
2020-12-18 13:31:01 -08:00

315 lines
11 KiB
C++

/*
* Copyright (c) 2018-2020 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <mesosphere.hpp>
namespace ams::kern {
namespace {
ALWAYS_INLINE bool ReadFromUser(s32 *out, KProcessAddress address) {
return UserspaceAccess::CopyMemoryFromUserSize32Bit(out, GetVoidPointer(address));
}
ALWAYS_INLINE bool DecrementIfLessThan(s32 *out, KProcessAddress address, s32 value) {
KScopedInterruptDisable di;
if (!cpu::CanAccessAtomic(address)) {
return false;
}
return UserspaceAccess::DecrementIfLessThanAtomic(out, GetPointer<s32>(address), value);
}
ALWAYS_INLINE bool UpdateIfEqual(s32 *out, KProcessAddress address, s32 value, s32 new_value) {
KScopedInterruptDisable di;
if (!cpu::CanAccessAtomic(address)) {
return false;
}
return UserspaceAccess::UpdateIfEqualAtomic(out, GetPointer<s32>(address), value, new_value);
}
}
Result KAddressArbiter::Signal(uintptr_t addr, s32 count) {
/* Perform signaling. */
s32 num_waiters = 0;
{
KScopedSchedulerLock sl;
auto it = m_tree.nfind_light({ addr, -1 });
while ((it != m_tree.end()) && (count <= 0 || num_waiters < count) && (it->GetAddressArbiterKey() == addr)) {
KThread *target_thread = std::addressof(*it);
target_thread->SetSyncedObject(nullptr, ResultSuccess());
AMS_ASSERT(target_thread->IsWaitingForAddressArbiter());
target_thread->Wakeup();
it = m_tree.erase(it);
target_thread->ClearAddressArbiter();
++num_waiters;
}
}
return ResultSuccess();
}
Result KAddressArbiter::SignalAndIncrementIfEqual(uintptr_t addr, s32 value, s32 count) {
/* Perform signaling. */
s32 num_waiters = 0;
{
KScopedSchedulerLock sl;
/* Check the userspace value. */
s32 user_value;
R_UNLESS(UpdateIfEqual(std::addressof(user_value), addr, value, value + 1), svc::ResultInvalidCurrentMemory());
R_UNLESS(user_value == value, svc::ResultInvalidState());
auto it = m_tree.nfind_light({ addr, -1 });
while ((it != m_tree.end()) && (count <= 0 || num_waiters < count) && (it->GetAddressArbiterKey() == addr)) {
KThread *target_thread = std::addressof(*it);
target_thread->SetSyncedObject(nullptr, ResultSuccess());
AMS_ASSERT(target_thread->IsWaitingForAddressArbiter());
target_thread->Wakeup();
it = m_tree.erase(it);
target_thread->ClearAddressArbiter();
++num_waiters;
}
}
return ResultSuccess();
}
Result KAddressArbiter::SignalAndModifyByWaitingCountIfEqual(uintptr_t addr, s32 value, s32 count) {
/* Perform signaling. */
s32 num_waiters = 0;
{
KScopedSchedulerLock sl;
auto it = m_tree.nfind_light({ addr, -1 });
/* Determine the updated value. */
s32 new_value;
if (GetTargetFirmware() >= TargetFirmware_7_0_0) {
if (count <= 0) {
if ((it != m_tree.end()) && (it->GetAddressArbiterKey() == addr)) {
new_value = value - 2;
} else {
new_value = value + 1;
}
} else {
if ((it != m_tree.end()) && (it->GetAddressArbiterKey() == addr)) {
auto tmp_it = it;
s32 tmp_num_waiters = 0;
while ((++tmp_it != m_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;
}
}
} else {
if (count <= 0) {
if ((it != m_tree.end()) && (it->GetAddressArbiterKey() == addr)) {
new_value = value - 1;
} else {
new_value = value + 1;
}
} else {
auto tmp_it = it;
s32 tmp_num_waiters = 0;
while ((tmp_it != m_tree.end()) && (tmp_it->GetAddressArbiterKey() == addr) && (tmp_num_waiters < count + 1)) {
++tmp_num_waiters;
++tmp_it;
}
if (tmp_num_waiters == 0) {
new_value = value + 1;
} else if (tmp_num_waiters <= count) {
new_value = value - 1;
} else {
new_value = value;
}
}
}
/* Check the userspace value. */
s32 user_value;
bool succeeded;
if (value != new_value) {
succeeded = UpdateIfEqual(std::addressof(user_value), addr, value, new_value);
} else {
succeeded = ReadFromUser(std::addressof(user_value), addr);
}
R_UNLESS(succeeded, svc::ResultInvalidCurrentMemory());
R_UNLESS(user_value == value, svc::ResultInvalidState());
while ((it != m_tree.end()) && (count <= 0 || num_waiters < count) && (it->GetAddressArbiterKey() == addr)) {
KThread *target_thread = std::addressof(*it);
target_thread->SetSyncedObject(nullptr, ResultSuccess());
AMS_ASSERT(target_thread->IsWaitingForAddressArbiter());
target_thread->Wakeup();
it = m_tree.erase(it);
target_thread->ClearAddressArbiter();
++num_waiters;
}
}
return ResultSuccess();
}
Result KAddressArbiter::WaitIfLessThan(uintptr_t addr, s32 value, bool decrement, s64 timeout) {
/* Prepare to wait. */
KThread *cur_thread = GetCurrentThreadPointer();
KHardwareTimer *timer;
{
KScopedSchedulerLockAndSleep slp(std::addressof(timer), cur_thread, timeout);
/* Check that the thread isn't terminating. */
if (cur_thread->IsTerminationRequested()) {
slp.CancelSleep();
return svc::ResultTerminationRequested();
}
/* Set the synced object. */
cur_thread->SetSyncedObject(nullptr, ams::svc::ResultTimedOut());
/* Read the value from userspace. */
s32 user_value;
bool succeeded;
if (decrement) {
succeeded = DecrementIfLessThan(std::addressof(user_value), addr, value);
} else {
succeeded = ReadFromUser(std::addressof(user_value), addr);
}
if (!succeeded) {
slp.CancelSleep();
return svc::ResultInvalidCurrentMemory();
}
/* Check that the value is less than the specified one. */
if (user_value >= value) {
slp.CancelSleep();
return svc::ResultInvalidState();
}
/* Check that the timeout is non-zero. */
if (timeout == 0) {
slp.CancelSleep();
return svc::ResultTimedOut();
}
/* Set the arbiter. */
cur_thread->SetAddressArbiter(std::addressof(m_tree), addr);
m_tree.insert(*cur_thread);
cur_thread->SetState(KThread::ThreadState_Waiting);
}
/* Cancel the timer wait. */
if (timer != nullptr) {
timer->CancelTask(cur_thread);
}
/* Remove from the address arbiter. */
{
KScopedSchedulerLock sl;
if (cur_thread->IsWaitingForAddressArbiter()) {
m_tree.erase(m_tree.iterator_to(*cur_thread));
cur_thread->ClearAddressArbiter();
}
}
/* Get the result. */
KSynchronizationObject *dummy;
return cur_thread->GetWaitResult(std::addressof(dummy));
}
Result KAddressArbiter::WaitIfEqual(uintptr_t addr, s32 value, s64 timeout) {
/* Prepare to wait. */
KThread *cur_thread = GetCurrentThreadPointer();
KHardwareTimer *timer;
{
KScopedSchedulerLockAndSleep slp(std::addressof(timer), cur_thread, timeout);
/* Check that the thread isn't terminating. */
if (cur_thread->IsTerminationRequested()) {
slp.CancelSleep();
return svc::ResultTerminationRequested();
}
/* Set the synced object. */
cur_thread->SetSyncedObject(nullptr, ams::svc::ResultTimedOut());
/* Read the value from userspace. */
s32 user_value;
if (!ReadFromUser(std::addressof(user_value), addr)) {
slp.CancelSleep();
return svc::ResultInvalidCurrentMemory();
}
/* Check that the value is equal. */
if (value != user_value) {
slp.CancelSleep();
return svc::ResultInvalidState();
}
/* Check that the timeout is non-zero. */
if (timeout == 0) {
slp.CancelSleep();
return svc::ResultTimedOut();
}
/* Set the arbiter. */
cur_thread->SetAddressArbiter(std::addressof(m_tree), addr);
m_tree.insert(*cur_thread);
cur_thread->SetState(KThread::ThreadState_Waiting);
}
/* Cancel the timer wait. */
if (timer != nullptr) {
timer->CancelTask(cur_thread);
}
/* Remove from the address arbiter. */
{
KScopedSchedulerLock sl;
if (cur_thread->IsWaitingForAddressArbiter()) {
m_tree.erase(m_tree.iterator_to(*cur_thread));
cur_thread->ClearAddressArbiter();
}
}
/* Get the result. */
KSynchronizationObject *dummy;
return cur_thread->GetWaitResult(std::addressof(dummy));
}
}