[Denali] Move signaling out of the command class.

sys/denali/ahci/ahci_controller.cpp

@@ -243,12 +243,8 @@ glcr::ErrorCode AhciController::LoadDevices() {
     }
 
     devices_[i] = new AhciPort(reinterpret_cast<AhciPortHba*>(port_addr));
-
-    if (devices_[i]->IsSata()) {
-      IdentifyDeviceCommand identify(devices_[i].get());
-      devices_[i]->IssueCommand(&identify);
-      identify.WaitComplete();
-    }
+    // TODO: Maybe continue to the next device if this fails.
+    RET_ERR(devices_[i]->Identify());
   }
   return glcr::OK;
 }

sys/denali/ahci/ahci_port.cpp

@@ -28,6 +28,7 @@ AhciPort::AhciPort(AhciPortHba* port) : port_struct_(port) {
   command_tables_ = glcr::ArrayView(
       reinterpret_cast<CommandTable*>(command_structures_.vaddr() + 0x500), 32);
 
+  command_signals_ = glcr::Array<mmth::Semaphore>(32);
   for (uint64_t i = 0; i < 32; i++) {
     // This leaves space for 2 prdt entries.
     command_list_->command_headers[i].command_table_base_addr =
@@ -41,7 +42,17 @@ AhciPort::AhciPort(AhciPortHba* port) : port_struct_(port) {
   port_struct_->command |= kCommand_Start;
 }
 
-glcr::ErrorCode AhciPort::IssueCommand(Command* command) {
+glcr::ErrorCode AhciPort::Identify() {
+  if (IsSata()) {
+    IdentifyDeviceCommand identify(this);
+    ASSIGN_OR_RETURN(auto* sem, IssueCommand(&identify));
+    sem->Wait();
+    identify.OnComplete();
+  }
+  return glcr::OK;
+}
+
+glcr::ErrorOr<mmth::Semaphore*> AhciPort::IssueCommand(Command* command) {
   uint64_t slot;
   for (slot = 0; slot < 32; slot++) {
     if (commands_[slot] == nullptr) {
@@ -65,7 +76,7 @@ glcr::ErrorCode AhciPort::IssueCommand(Command* command) {
   commands_issued_ |= (1 << slot);
   port_struct_->command_issue |= (1 << slot);
 
-  return glcr::OK;
+  return &command_signals_[slot];
 }
 
 void AhciPort::DumpInfo() {
@@ -152,7 +163,7 @@ void AhciPort::HandleIrq() {
     if (commands_finished & (1 << i)) {
       commands_issued_ &= ~(1 << i);
       // FIXME: Pass error codes to the callback.
-      commands_[i]->SignalComplete();
+      command_signals_[i].Signal();
       commands_[i] = nullptr;
     }
   }

sys/denali/ahci/ahci_port.h

@@ -1,7 +1,9 @@
 #pragma once
 
+#include <glacier/container/array.h>
 #include <glacier/container/array_view.h>
 #include <glacier/status/error.h>
+#include <glacier/status/error_or.h>
 #include <mammoth/util/memory_region.h>
 #include <ztypes.h>
 
@@ -19,7 +21,9 @@ class AhciPort {
   bool IsSata() { return port_struct_->signature == 0x101; }
   bool IsInit() { return port_struct_ != nullptr && command_structures_; }
 
-  glcr::ErrorCode IssueCommand(Command* command);
+  glcr::ErrorCode Identify();
+
+  glcr::ErrorOr<mmth::Semaphore*> IssueCommand(Command* command);
 
   void HandleIrq();
 
@@ -35,5 +39,6 @@ class AhciPort {
   glcr::ArrayView<CommandTable> command_tables_;
 
   Command* commands_[32];
+  glcr::Array<mmth::Semaphore> command_signals_;
   uint32_t commands_issued_ = 0;
 };

sys/denali/ahci/command.cpp

@@ -19,12 +19,6 @@ void* memcpy(void* dest, const void* src, uint64_t count) {
 
 Command::~Command() {}
 
-void Command::SignalComplete() {
-  OnComplete();
-  callback_semaphore_.Signal();
-}
-void Command::WaitComplete() { callback_semaphore_.Wait(); }
-
 void IdentifyDeviceCommand::PopulateFis(uint8_t* command_fis) {
   HostToDeviceRegisterFis fis __attribute__((aligned(16))){
       .fis_type = FIS_TYPE_REG_H2D,

sys/denali/ahci/command.h

@@ -14,15 +14,6 @@ class Command {
   virtual ~Command();
   virtual void PopulateFis(uint8_t* command_fis) = 0;
   virtual void PopulatePrdt(PhysicalRegionDescriptor* prdt) = 0;
-  void WaitComplete();
-  void SignalComplete();
-
-  virtual void OnComplete() {}
-
- private:
-  // TODO: Make this owned by the device so that we don't have to create a new
-  // one with the kernel every time a command is issued.
-  mmth::Semaphore callback_semaphore_;
 };
 
 class IdentifyDeviceCommand : public Command {
@@ -31,7 +22,7 @@ class IdentifyDeviceCommand : public Command {
   virtual void PopulateFis(uint8_t* command_fis) override;
   virtual void PopulatePrdt(PhysicalRegionDescriptor* prdt) override;
 
-  virtual void OnComplete() override;
+  void OnComplete();
 
  private:
   AhciPort* port_;

sys/denali/denali_server.cpp

@@ -21,9 +21,8 @@ glcr::Status DenaliServer::HandleRead(const ReadRequest& req,
       mmth::OwnedMemoryRegion::ContiguousPhysical(req.size() * 512, &paddr);
 
   DmaReadCommand command(req.lba(), req.size(), paddr);
-  device->IssueCommand(&command);
-
-  command.WaitComplete();
+  ASSIGN_OR_RETURN(auto semaphore, device->IssueCommand(&command));
+  semaphore->Wait();
 
   resp.set_device_id(req.device_id());
   resp.set_size(req.size());
@@ -51,8 +50,8 @@ glcr::Status DenaliServer::HandleReadMany(const ReadManyRequest& req,
     uint64_t lba = req.lba().at(i);
     uint64_t size = req.sector_cnt().at(i);
     DmaReadCommand command(lba, size, region_paddr);
-    device->IssueCommand(&command);
-    command.WaitComplete();
+    ASSIGN_OR_RETURN(auto semaphore, device->IssueCommand(&command));
+    semaphore->Wait();
 
     region_paddr += size * 512;
   }