Kernel/AHCI: Use interrupts for IO operations

Instead of polling if the device ended the operation, we can just use
interrupts for signalling about end of IO operation.
In similar way, we use interrupts during device detection.

Also, we use the new Work Queue mechanism introduced by @tomuta to allow
better performance and stability :)

3 files changed, 132 insertions, 72 deletions

diff --git a/Kernel/Storage/AHCIController.h b/Kernel/Storage/AHCIController.h
index 73714c0e47..9fbef60410 100644
--- a/Kernel/Storage/AHCIController.h
+++ b/Kernel/Storage/AHCIController.h
@@ -37,9 +37,11 @@ namespace Kernel {
 
 class AsyncBlockDeviceRequest;
 class AHCIPortHandler;
+class AHCIPort;
 class AHCIController final : public StorageController
     , public PCI::DeviceController {
     friend class AHCIPortHandler;
+    friend class AHCIPort;
     AK_MAKE_ETERNAL
 public:
 public:
diff --git a/Kernel/Storage/AHCIPort.cpp b/Kernel/Storage/AHCIPort.cpp
index 3dd8dcbbe0..70670cba3d 100644
--- a/Kernel/Storage/AHCIPort.cpp
+++ b/Kernel/Storage/AHCIPort.cpp
@@ -32,6 +32,7 @@
 #include <Kernel/VM/AnonymousVMObject.h>
 #include <Kernel/VM/MemoryManager.h>
 #include <Kernel/VM/TypedMapping.h>
+#include <Kernel/WorkQueue.h>
 
 namespace Kernel {
 
@@ -96,17 +97,49 @@ void AHCIPort::handle_interrupt()
     if (m_interrupt_status.raw_value() == 0) {
         return;
     }
-    if (m_interrupt_status.is_set(AHCI::PortInterruptFlag::PRC) || m_interrupt_status.is_set(AHCI::PortInterruptFlag::PC)) {
-        reset();
-        return;
+    if (m_interrupt_status.is_set(AHCI::PortInterruptFlag::PRC) && m_interrupt_status.is_set(AHCI::PortInterruptFlag::PC)) {
+        clear_sata_error_register();
+        m_wait_connect_for_completion = true;
     }
     if (m_interrupt_status.is_set(AHCI::PortInterruptFlag::INF)) {
         reset();
         return;
     }
     if (m_interrupt_status.is_set(AHCI::PortInterruptFlag::IF) || m_interrupt_status.is_set(AHCI::PortInterruptFlag::TFE) || m_interrupt_status.is_set(AHCI::PortInterruptFlag::HBD) || m_interrupt_status.is_set(AHCI::PortInterruptFlag::HBF)) {
-        recover_from_fatal_error();
+        g_io_work->queue([this]() {
+            recover_from_fatal_error();
+        });
+        return;
+    }
+    if (m_interrupt_status.is_set(AHCI::PortInterruptFlag::DHR) || m_interrupt_status.is_set(AHCI::PortInterruptFlag::PS)) {
+        m_wait_for_completion = false;
+
+        // Now schedule reading/writing the buffer as soon as we leave the irq handler.
+        // This is important so that we can safely access the buffers, which could
+        // trigger page faults
+        if (!m_current_request) {
+            dbgln_if(AHCI_DEBUG, "AHCI Port {}: Request handled, probably identify request", representative_port_index());
+        } else {
+            g_io_work->queue([this]() {
+                dbgln_if(AHCI_DEBUG, "AHCI Port {}: Request handled", representative_port_index());
+                LOCKER(m_lock);
+                VERIFY(m_current_request);
+                VERIFY(m_current_scatter_list);
+                if (m_current_request->request_type() == AsyncBlockDeviceRequest::Read) {
+                    if (!m_current_request->write_to_buffer(m_current_request->buffer(), m_current_scatter_list->dma_region().as_ptr(), m_connected_device->block_size() * m_current_request->block_count())) {
+                        dbgln_if(AHCI_DEBUG, "AHCI Port {}: Request failure, memory fault occurred when reading in data.", representative_port_index());
+                        m_current_scatter_list = nullptr;
+                        complete_current_request(AsyncDeviceRequest::MemoryFault);
+                        return;
+                    }
+                }
+                m_current_scatter_list = nullptr;
+                dbgln_if(AHCI_DEBUG, "AHCI Port {}: Request success", representative_port_index());
+                complete_current_request(AsyncDeviceRequest::Success);
+            });
+        }
     }
+
     m_interrupt_status.clear();
 }
 
@@ -117,8 +150,10 @@ bool AHCIPort::is_interrupts_enabled() const
 
 void AHCIPort::recover_from_fatal_error()
 {
-    ScopedSpinLock lock(m_lock);
+    LOCKER(m_lock);
+    ScopedSpinLock lock(m_hard_lock);
     dmesgln("{}: AHCI Port {} fatal error, shutting down!", m_parent_handler->hba_controller()->pci_address(), representative_port_index());
+    dmesgln("{}: AHCI Port {} fatal error, SError {}", m_parent_handler->hba_controller()->pci_address(), representative_port_index(), (u32)m_port_registers.serr);
     stop_command_list_processing();
     stop_fis_receiving();
     m_interrupt_enable.clear();
@@ -192,8 +227,6 @@ void AHCIPort::eject()
             try_disambiguate_sata_error();
             VERIFY_NOT_REACHED();
         }
-        if ((m_port_registers.ci & (1 << unused_command_header.value())) == 0)
-            break;
     }
     dbgln("AHCI Port {}: Eject Drive", representative_port_index());
     return;
@@ -201,7 +234,8 @@ void AHCIPort::eject()
 
 bool AHCIPort::reset()
 {
-    ScopedSpinLock lock(m_lock);
+    LOCKER(m_lock);
+    ScopedSpinLock lock(m_hard_lock);
 
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Resetting", representative_port_index());
 
@@ -217,20 +251,21 @@ bool AHCIPort::reset()
     full_memory_barrier();
     clear_sata_error_register();
     full_memory_barrier();
-    if (!initiate_sata_reset()) {
+    if (!initiate_sata_reset(lock)) {
         return false;
     }
-    return initialize();
+    return initialize(lock);
 }
 
 bool AHCIPort::initialize_without_reset()
 {
-    ScopedSpinLock lock(m_lock);
+    LOCKER(m_lock);
+    ScopedSpinLock lock(m_hard_lock);
     dmesgln("AHCI Port {}: {}", representative_port_index(), try_disambiguate_sata_status());
-    return initialize();
+    return initialize(lock);
 }
 
-bool AHCIPort::initialize()
+bool AHCIPort::initialize(ScopedSpinLock<SpinLock<u8>>& main_lock)
 {
     VERIFY(m_lock.is_locked());
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Initialization. Signature = 0x{:08x}", representative_port_index(), static_cast<u32>(m_port_registers.sig));
@@ -255,7 +290,7 @@ bool AHCIPort::initialize()
     size_t logical_sector_size = 512;
     size_t physical_sector_size = 512;
     u64 max_addressable_sector = 0;
-    if (identify_device()) {
+    if (identify_device(main_lock)) {
         auto identify_block = map_typed<ATAIdentifyBlock>(m_parent_handler->get_identify_metadata_physical_region(m_port_index));
         // Check if word 106 is valid before using it!
         if ((identify_block->physical_sector_size_to_logical_sector_size >> 14) == 1) {
@@ -361,6 +396,7 @@ void AHCIPort::try_disambiguate_sata_error()
 void AHCIPort::rebase()
 {
     VERIFY(m_lock.is_locked());
+    VERIFY(m_hard_lock.is_locked());
     VERIFY(!m_command_list_page.is_null() && !m_fis_receive_page.is_null());
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Rebasing.", representative_port_index());
     full_memory_barrier();
@@ -394,6 +430,7 @@ bool AHCIPort::is_operable() const
 void AHCIPort::set_active_state() const
 {
     VERIFY(m_lock.is_locked());
+    VERIFY(m_hard_lock.is_locked());
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Switching to active state.", representative_port_index());
     m_port_registers.cmd = (m_port_registers.cmd & 0x0ffffff) | (1 << 28);
 }
@@ -401,6 +438,7 @@ void AHCIPort::set_active_state() const
 void AHCIPort::set_sleep_state() const
 {
     VERIFY(m_lock.is_locked());
+    VERIFY(m_hard_lock.is_locked());
     m_port_registers.cmd = (m_port_registers.cmd & 0x0ffffff) | (0b1000 << 28);
 }
 
@@ -433,40 +471,35 @@ Optional<AsyncDeviceRequest::RequestResult> AHCIPort::prepare_and_set_scatter_li
 
 void AHCIPort::start_request(AsyncBlockDeviceRequest& request)
 {
-    ScopedSpinLock lock(m_lock);
-    VERIFY(!m_current_scatter_list);
+    LOCKER(m_lock);
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Request start", representative_port_index());
+    VERIFY(!m_current_request);
+    VERIFY(!m_current_scatter_list);
+
+    m_current_request = request;
 
     auto result = prepare_and_set_scatter_list(request);
     if (result.has_value()) {
         dbgln_if(AHCI_DEBUG, "AHCI Port {}: Request failure.", representative_port_index());
-        request.complete(result.value());
+        m_lock.unlock();
+        complete_current_request(result.value());
         return;
     }
 
     auto success = access_device(request.request_type(), request.block_index(), request.block_count());
     if (!success) {
         dbgln_if(AHCI_DEBUG, "AHCI Port {}: Request failure.", representative_port_index());
-        request.complete(AsyncDeviceRequest::Failure);
+        m_lock.unlock();
+        complete_current_request(AsyncDeviceRequest::Failure);
         return;
     }
-
-    if (request.request_type() == AsyncBlockDeviceRequest::Read) {
-        if (!request.write_to_buffer(request.buffer(), m_current_scatter_list->dma_region().as_ptr(), m_connected_device->block_size() * request.block_count())) {
-            dbgln_if(AHCI_DEBUG, "AHCI Port {}: Request failure, memory fault occurred when reading in data.", representative_port_index());
-            request.complete(AsyncDeviceRequest::MemoryFault);
-            m_current_scatter_list = nullptr;
-            return;
-        }
-    }
-    m_current_scatter_list = nullptr;
-    dbgln_if(AHCI_DEBUG, "AHCI Port {}: Request success", representative_port_index());
-    request.complete(AsyncDeviceRequest::Success);
 }
 
-void AHCIPort::complete_current_request(AsyncDeviceRequest::RequestResult)
+void AHCIPort::complete_current_request(AsyncDeviceRequest::RequestResult result)
 {
-    VERIFY(m_lock.is_locked());
+    VERIFY(m_current_request);
+    m_current_request->complete(result);
+    m_current_request.clear();
 }
 
 bool AHCIPort::spin_until_ready() const
@@ -490,7 +523,9 @@ bool AHCIPort::access_device(AsyncBlockDeviceRequest::RequestType direction, u64
     VERIFY(m_lock.is_locked());
     VERIFY(m_connected_device);
     VERIFY(is_operable());
+    VERIFY(m_lock.is_locked());
     VERIFY(m_current_scatter_list);
+    ScopedSpinLock lock(m_hard_lock);
 
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Do a {}, lba {}, block count {}", representative_port_index(), direction == AsyncBlockDeviceRequest::RequestType::Write ? "write" : "read", lba, block_count);
     if (!spin_until_ready())
@@ -528,6 +563,7 @@ bool AHCIPort::access_device(AsyncBlockDeviceRequest::RequestType direction, u64
         command_table.descriptors[scatter_entry_index].byte_count = PAGE_SIZE - 1;
         scatter_entry_index++;
     }
+    command_table.descriptors[scatter_entry_index].byte_count = (PAGE_SIZE - 1) | (1 << 31);
 
     memset(const_cast<u8*>(command_table.atapi_command), 0, 32);
 
@@ -561,20 +597,14 @@ bool AHCIPort::access_device(AsyncBlockDeviceRequest::RequestType direction, u64
         return false;
 
     full_memory_barrier();
-    start_command_list_processing();
-    full_memory_barrier();
     mark_command_header_ready_to_process(unused_command_header.value());
     full_memory_barrier();
 
-    while (1) {
-        if ((m_port_registers.ci & (1 << unused_command_header.value())) == 0)
-            break;
-    }
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Do a {}, lba {}, block count {} @ {}, ended", representative_port_index(), direction == AsyncBlockDeviceRequest::RequestType::Write ? "write" : "read", lba, block_count, m_dma_buffers[0].paddr());
     return true;
 }
 
-bool AHCIPort::identify_device()
+bool AHCIPort::identify_device(ScopedSpinLock<SpinLock<u8>>& main_lock)
 {
     VERIFY(m_lock.is_locked());
     VERIFY(is_operable());
@@ -609,25 +639,35 @@ bool AHCIPort::identify_device()
     if (!spin_until_ready())
         return false;
 
-    full_memory_barrier();
-    mark_command_header_ready_to_process(unused_command_header.value());
-    full_memory_barrier();
-
-    while (1) {
-        if (m_port_registers.serr != 0) {
-            dbgln("AHCI Port {}: Identify failed, SError 0x{:08x}", representative_port_index(), (u32)m_port_registers.serr);
-            try_disambiguate_sata_error();
-            return false;
+    // FIXME: Find a better way to send IDENTIFY DEVICE and getting an interrupt!
+    {
+        main_lock.unlock();
+        VERIFY_INTERRUPTS_ENABLED();
+        full_memory_barrier();
+        m_wait_for_completion = true;
+        dbgln_if(AHCI_DEBUG, "AHCI Port {}: Marking command header at index {} as ready to identify device", representative_port_index(), unused_command_header.value());
+        m_port_registers.ci = 1 << unused_command_header.value();
+        full_memory_barrier();
+
+        while (1) {
+            if (m_port_registers.serr != 0) {
+                dbgln("AHCI Port {}: Identify failed, SError 0x{:08x}", representative_port_index(), (u32)m_port_registers.serr);
+                try_disambiguate_sata_error();
+                return false;
+            }
+            if (!m_wait_for_completion)
+                break;
         }
-        if ((m_port_registers.ci & (1 << unused_command_header.value())) == 0)
-            break;
+        main_lock.lock();
     }
+
     return true;
 }
 
 bool AHCIPort::shutdown()
 {
-    ScopedSpinLock lock(m_lock);
+    LOCKER(m_lock);
+    ScopedSpinLock lock(m_hard_lock);
     rebase();
     set_interface_state(AHCI::DeviceDetectionInitialization::DisableInterface);
     return true;
@@ -650,6 +690,7 @@ Optional<u8> AHCIPort::try_to_find_unused_command_header()
 void AHCIPort::start_command_list_processing() const
 {
     VERIFY(m_lock.is_locked());
+    VERIFY(m_hard_lock.is_locked());
     VERIFY(is_operable());
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Starting command list processing.", representative_port_index());
     m_port_registers.cmd = m_port_registers.cmd | 1;
@@ -658,7 +699,10 @@ void AHCIPort::start_command_list_processing() const
 void AHCIPort::mark_command_header_ready_to_process(u8 command_header_index) const
 {
     VERIFY(m_lock.is_locked());
+    VERIFY(m_hard_lock.is_locked());
     VERIFY(is_operable());
+    VERIFY(!m_wait_for_completion);
+    m_wait_for_completion = true;
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Marking command header at index {} as ready to process.", representative_port_index(), command_header_index);
     m_port_registers.ci = 1 << command_header_index;
 }
@@ -666,6 +710,7 @@ void AHCIPort::mark_command_header_ready_to_process(u8 command_header_index) con
 void AHCIPort::stop_command_list_processing() const
 {
     VERIFY(m_lock.is_locked());
+    VERIFY(m_hard_lock.is_locked());
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Stopping command list processing.", representative_port_index());
     m_port_registers.cmd = m_port_registers.cmd & 0xfffffffe;
 }
@@ -673,6 +718,7 @@ void AHCIPort::stop_command_list_processing() const
 void AHCIPort::start_fis_receiving() const
 {
     VERIFY(m_lock.is_locked());
+    VERIFY(m_hard_lock.is_locked());
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Starting FIS receiving.", representative_port_index());
     m_port_registers.cmd = m_port_registers.cmd | (1 << 4);
 }
@@ -680,6 +726,7 @@ void AHCIPort::start_fis_receiving() const
 void AHCIPort::power_on() const
 {
     VERIFY(m_lock.is_locked());
+    VERIFY(m_hard_lock.is_locked());
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Power on. Cold presence detection? {}", representative_port_index(), (bool)(m_port_registers.cmd & (1 << 20)));
     if (!(m_port_registers.cmd & (1 << 20)))
         return;
@@ -690,6 +737,7 @@ void AHCIPort::power_on() const
 void AHCIPort::spin_up() const
 {
     VERIFY(m_lock.is_locked());
+    VERIFY(m_hard_lock.is_locked());
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Spin up. Staggered spin up? {}", representative_port_index(), m_parent_handler->hba_capabilities().staggered_spin_up_supported);
     if (!m_parent_handler->hba_capabilities().staggered_spin_up_supported)
         return;
@@ -700,13 +748,15 @@ void AHCIPort::spin_up() const
 void AHCIPort::stop_fis_receiving() const
 {
     VERIFY(m_lock.is_locked());
+    VERIFY(m_hard_lock.is_locked());
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Stopping FIS receiving.", representative_port_index());
     m_port_registers.cmd = m_port_registers.cmd & 0xFFFFFFEF;
 }
 
-bool AHCIPort::initiate_sata_reset()
+bool AHCIPort::initiate_sata_reset(ScopedSpinLock<SpinLock<u8>>& main_lock)
 {
     VERIFY(m_lock.is_locked());
+    VERIFY(m_hard_lock.is_locked());
     dbgln_if(AHCI_DEBUG, "AHCI Port {}: Initiate SATA reset", representative_port_index());
     stop_command_list_processing();
     full_memory_barrier();
@@ -725,17 +775,24 @@ bool AHCIPort::initiate_sata_reset()
     set_interface_state(AHCI::DeviceDetectionInitialization::PerformInterfaceInitializationSequence);
     // The AHCI specification says to wait now a 1 millisecond
     IO::delay(1000);
-    full_memory_barrier();
-    set_interface_state(AHCI::DeviceDetectionInitialization::NoActionRequested);
-    full_memory_barrier();
-
-    retry = 0;
-    while (retry < 5000) {
-        if (!((m_port_registers.ssts & 0xf) == 0))
-            break;
-
-        IO::delay(10);
-        retry++;
+    // FIXME: Find a better way to opt-out temporarily from Scoped locking!
+    {
+        main_lock.unlock();
+        VERIFY_INTERRUPTS_ENABLED();
+        full_memory_barrier();
+        set_interface_state(AHCI::DeviceDetectionInitialization::NoActionRequested);
+        full_memory_barrier();
+        if (m_wait_connect_for_completion) {
+            retry = 0;
+            while (retry < 100000) {
+                if (is_phy_enabled())
+                    break;
+
+                IO::delay(10);
+                retry++;
+            }
+        }
+        main_lock.lock();
     }
 
     dmesgln("AHCI Port {}: {}", representative_port_index(), try_disambiguate_sata_status());
@@ -747,7 +804,6 @@ bool AHCIPort::initiate_sata_reset()
 
 void AHCIPort::set_interface_state(AHCI::DeviceDetectionInitialization requested_action)
 {
-    VERIFY(m_lock.is_locked());
     switch (requested_action) {
     case AHCI::DeviceDetectionInitialization::NoActionRequested:
         m_port_registers.sctl = (m_port_registers.sctl & 0xfffffff0);
diff --git a/Kernel/Storage/AHCIPort.h b/Kernel/Storage/AHCIPort.h
index 929e1640f7..42ed9b4464 100644
--- a/Kernel/Storage/AHCIPort.h
+++ b/Kernel/Storage/AHCIPort.h
@@ -34,6 +34,7 @@
 #include <Kernel/Lock.h>
 #include <Kernel/PhysicalAddress.h>
 #include <Kernel/Random.h>
+#include <Kernel/SpinLock.h>
 #include <Kernel/Storage/AHCI.h>
 #include <Kernel/Storage/AHCIPortHandler.h>
 #include <Kernel/Storage/StorageDevice.h>
@@ -83,7 +84,7 @@ public:
 
 private:
     bool is_phy_enabled() const { return (m_port_registers.ssts & 0xf) == 3; }
-    bool initialize();
+    bool initialize(ScopedSpinLock<SpinLock<u8>>&);
 
     UNMAP_AFTER_INIT AHCIPort(const AHCIPortHandler&, volatile AHCI::PortRegisters&, u32 port_index);
 
@@ -94,7 +95,7 @@ private:
     const char* try_disambiguate_sata_status();
     void try_disambiguate_sata_error();
 
-    bool initiate_sata_reset();
+    bool initiate_sata_reset(ScopedSpinLock<SpinLock<u8>>&);
     void rebase();
     void recover_from_fatal_error();
     bool shutdown();
@@ -111,7 +112,7 @@ private:
 
     bool spin_until_ready() const;
 
-    bool identify_device();
+    bool identify_device(ScopedSpinLock<SpinLock<u8>>&);
 
     ALWAYS_INLINE void start_command_list_processing() const;
     ALWAYS_INLINE void mark_command_header_ready_to_process(u8 command_header_index) const;
@@ -132,11 +133,12 @@ private:
     // Data members
 
     EntropySource m_entropy_source;
-    AsyncBlockDeviceRequest* m_current_request { nullptr };
-    u32 m_current_request_block_index { 0 };
-    bool m_current_request_uses_dma { false };
-    bool m_current_request_flushing_cache { false };
-    SpinLock<u8> m_lock;
+    RefPtr<AsyncBlockDeviceRequest> m_current_request;
+    SpinLock<u8> m_hard_lock;
+    Lock m_lock { "AHCIPort" };
+
+    mutable bool m_wait_for_completion { false };
+    bool m_wait_connect_for_completion { false };
 
     NonnullRefPtrVector<PhysicalPage> m_dma_buffers;
     NonnullRefPtrVector<PhysicalPage> m_command_table_pages;