Kernel: Protect PCI access with spinlock instead of mutex

2 files changed, 11 insertions, 12 deletions

diff --git a/Kernel/Bus/PCI/Access.cpp b/Kernel/Bus/PCI/Access.cpp
index 01f60168a0..bd4ee02a18 100644
--- a/Kernel/Bus/PCI/Access.cpp
+++ b/Kernel/Bus/PCI/Access.cpp
@@ -110,7 +110,7 @@ UNMAP_AFTER_INIT bool Access::initialize_for_one_pci_domain()
 
 void Access::add_host_controller_and_enumerate_attached_devices(NonnullOwnPtr<HostController> controller, Function<void(DeviceIdentifier const&)> callback)
 {
-    MutexLocker locker(m_access_lock);
+    SpinlockLocker locker(m_access_lock);
     SpinlockLocker scan_locker(m_scan_lock);
     auto domain_number = controller->domain_number();
 
@@ -137,7 +137,7 @@ UNMAP_AFTER_INIT Access::Access()
 
 UNMAP_AFTER_INIT void Access::rescan_hardware()
 {
-    MutexLocker locker(m_access_lock);
+    SpinlockLocker locker(m_access_lock);
     SpinlockLocker scan_locker(m_scan_lock);
     VERIFY(m_device_identifiers.is_empty());
     for (auto it = m_host_controllers.begin(); it != m_host_controllers.end(); ++it) {
@@ -149,7 +149,7 @@ UNMAP_AFTER_INIT void Access::rescan_hardware()
 
 void Access::fast_enumerate(Function<void(DeviceIdentifier const&)>& callback) const
 {
-    MutexLocker locker(m_access_lock);
+    SpinlockLocker locker(m_access_lock);
     VERIFY(!m_device_identifiers.is_empty());
     for (auto const& device_identifier : m_device_identifiers) {
         callback(device_identifier);
@@ -171,21 +171,21 @@ DeviceIdentifier Access::get_device_identifier(Address address) const
 
 void Access::write8_field(Address address, u32 field, u8 value)
 {
-    MutexLocker lock(m_access_lock);
+    SpinlockLocker locker(m_access_lock);
     VERIFY(m_host_controllers.contains(address.domain()));
     auto& controller = *m_host_controllers.get(address.domain()).value();
     controller.write8_field(address.bus(), address.device(), address.function(), field, value);
 }
 void Access::write16_field(Address address, u32 field, u16 value)
 {
-    MutexLocker lock(m_access_lock);
+    SpinlockLocker locker(m_access_lock);
     VERIFY(m_host_controllers.contains(address.domain()));
     auto& controller = *m_host_controllers.get(address.domain()).value();
     controller.write16_field(address.bus(), address.device(), address.function(), field, value);
 }
 void Access::write32_field(Address address, u32 field, u32 value)
 {
-    MutexLocker lock(m_access_lock);
+    SpinlockLocker locker(m_access_lock);
     VERIFY(m_host_controllers.contains(address.domain()));
     auto& controller = *m_host_controllers.get(address.domain()).value();
     controller.write32_field(address.bus(), address.device(), address.function(), field, value);
@@ -202,21 +202,21 @@ u16 Access::read16_field(Address address, RegisterOffset field)
 
 u8 Access::read8_field(Address address, u32 field)
 {
-    MutexLocker lock(m_access_lock);
+    SpinlockLocker locker(m_access_lock);
     VERIFY(m_host_controllers.contains(address.domain()));
     auto& controller = *m_host_controllers.get(address.domain()).value();
     return controller.read8_field(address.bus(), address.device(), address.function(), field);
 }
 u16 Access::read16_field(Address address, u32 field)
 {
-    MutexLocker lock(m_access_lock);
+    SpinlockLocker locker(m_access_lock);
     VERIFY(m_host_controllers.contains(address.domain()));
     auto& controller = *m_host_controllers.get(address.domain()).value();
     return controller.read16_field(address.bus(), address.device(), address.function(), field);
 }
 u32 Access::read32_field(Address address, u32 field)
 {
-    MutexLocker lock(m_access_lock);
+    SpinlockLocker locker(m_access_lock);
     VERIFY(m_host_controllers.contains(address.domain()));
     auto& controller = *m_host_controllers.get(address.domain()).value();
     return controller.read32_field(address.bus(), address.device(), address.function(), field);
diff --git a/Kernel/Bus/PCI/Access.h b/Kernel/Bus/PCI/Access.h
index 0c9be8c064..f5c42c625c 100644
--- a/Kernel/Bus/PCI/Access.h
+++ b/Kernel/Bus/PCI/Access.h
@@ -36,7 +36,7 @@ public:
     DeviceIdentifier get_device_identifier(Address address) const;
 
     Spinlock const& scan_lock() const { return m_scan_lock; }
-    Mutex const& access_lock() const { return m_access_lock; }
+    RecursiveSpinlock const& access_lock() const { return m_access_lock; }
 
     void add_host_controller_and_enumerate_attached_devices(NonnullOwnPtr<HostController>, Function<void(DeviceIdentifier const&)> callback);
 
@@ -51,8 +51,7 @@ private:
     Vector<Capability> get_capabilities(Address);
     Optional<u8> get_capabilities_pointer(Address address);
 
-    // General Data-members
-    mutable Mutex m_access_lock;
+    mutable RecursiveSpinlock m_access_lock;
     mutable Spinlock m_scan_lock;
 
     HashMap<u32, NonnullOwnPtr<HostController>> m_host_controllers;