[Denali] Add a simpler command method and use it to send identify.

sys/denali/ahci/ahci_port.cpp

@@ -44,10 +44,21 @@ AhciPort::AhciPort(AhciPortHba* port) : port_struct_(port) {
 
 glcr::ErrorCode AhciPort::Identify() {
   if (IsSata()) {
-    IdentifyDeviceCommand identify(this);
+    CommandInfo identify{
+        .command = kIdentifyDevice,
+        .lba = 0,
+        .sectors = 1,
+        .paddr = 0,
+    };
+    auto region =
+        mmth::OwnedMemoryRegion::ContiguousPhysical(0x200, &identify.paddr);
     ASSIGN_OR_RETURN(auto* sem, IssueCommand(identify));
     sem->Wait();
-    identify.OnComplete();
+    uint16_t* ident = reinterpret_cast<uint16_t*>(region.vaddr());
+    uint32_t* sector_size = reinterpret_cast<uint32_t*>(ident + 117);
+    dbgln("Sector size: {}", *sector_size);
+    uint64_t* lbas = reinterpret_cast<uint64_t*>(ident + 100);
+    dbgln("LBA Count: {}", *lbas);
   }
   return glcr::OK;
 }
@@ -77,6 +88,61 @@ glcr::ErrorOr<mmth::Semaphore*> AhciPort::IssueCommand(const Command& command) {
   return &command_signals_[slot];
 }
 
+glcr::ErrorOr<mmth::Semaphore*> AhciPort::IssueCommand(
+    const CommandInfo& command) {
+  uint64_t slot;
+  for (slot = 0; slot < 32; slot++) {
+    if (!(commands_issued_ & (1 << slot))) {
+      break;
+    }
+  }
+  if (slot == 32) {
+    dbgln("All slots full");
+    return glcr::INTERNAL;
+  }
+
+  auto* fis = reinterpret_cast<HostToDeviceRegisterFis*>(
+      command_tables_[slot].command_fis);
+  *fis = HostToDeviceRegisterFis{
+      .fis_type = FIS_TYPE_REG_H2D,
+      .pmp_and_c = 0x80,
+      .command = command.command,
+      .featurel = 0,
+
+      .lba0 = static_cast<uint8_t>(command.lba & 0xFF),
+      .lba1 = static_cast<uint8_t>((command.lba >> 8) & 0xFF),
+      .lba2 = static_cast<uint8_t>((command.lba >> 16) & 0xFF),
+      .device = (1 << 6),  // ATA LBA Mode
+
+      .lba3 = static_cast<uint8_t>((command.lba >> 24) & 0xFF),
+      .lba4 = static_cast<uint8_t>((command.lba >> 32) & 0xFF),
+      .lba5 = static_cast<uint8_t>((command.lba >> 40) & 0xFF),
+      .featureh = 0,
+
+      .count = command.sectors,
+      .icc = 0,
+      .control = 0,
+
+      .reserved = 0,
+  };
+
+  command_tables_[slot].prdt[0].region_address = command.paddr;
+  command_tables_[slot].prdt[0].byte_count = 512 * command.sectors;
+
+  command_list_->command_headers[slot].prd_table_length = 1;
+  command_list_->command_headers[slot].command =
+      (sizeof(HostToDeviceRegisterFis) / 2) & 0x1F;
+  // Set prefetch bit.
+  command_list_->command_headers[slot].command |= (1 << 7);
+
+  // TODO: Synchronization-wise we need to ensure this is set in the same
+  // critical section as where we select a slot.
+  commands_issued_ |= (1 << slot);
+  port_struct_->command_issue |= (1 << slot);
+
+  return &command_signals_[slot];
+}
+
 void AhciPort::DumpInfo() {
   dbgln("Comlist: {x}", port_struct_->command_list_base);
   dbgln("FIS: {x}", port_struct_->fis_base);

sys/denali/ahci/ahci_port.h

@@ -24,6 +24,7 @@ class AhciPort {
   glcr::ErrorCode Identify();
 
   glcr::ErrorOr<mmth::Semaphore*> IssueCommand(const Command& command);
+  glcr::ErrorOr<mmth::Semaphore*> IssueCommand(const CommandInfo& command);
 
   void HandleIrq();
 

sys/denali/ahci/command.cpp

@@ -19,37 +19,6 @@ void* memcpy(void* dest, const void* src, uint64_t count) {
 
 Command::~Command() {}
 
-void IdentifyDeviceCommand::PopulateFis(uint8_t* command_fis) const {
-  HostToDeviceRegisterFis fis __attribute__((aligned(16))){
-      .fis_type = FIS_TYPE_REG_H2D,
-      .pmp_and_c = 0x80,
-      .command = kIdentifyDevice,
-      .device = 0,
-  };
-
-  memcpy(command_fis, &fis, sizeof(fis));
-}
-
-void IdentifyDeviceCommand::PopulatePrdt(PhysicalRegionDescriptor* prdt) const {
-  prdt[0].region_address = paddr_;
-  prdt[0].byte_count = 0x200 - 1;
-  dbgln("paddr: {x}", paddr_);
-  uint16_t* ident = reinterpret_cast<uint16_t*>(identify_.vaddr());
-  dbgln("vaddr: {x}", identify_.vaddr());
-  for (uint32_t i = 0; i < 256; i++) {
-    ident[i] = 0;
-  }
-}
-
-void IdentifyDeviceCommand::OnComplete() {
-  uint16_t* ident = reinterpret_cast<uint16_t*>(identify_.vaddr());
-  uint32_t* sector_size = reinterpret_cast<uint32_t*>(ident + 117);
-  dbgln("Sector size: {}", *sector_size);
-  uint64_t* lbas = reinterpret_cast<uint64_t*>(ident + 100);
-  dbgln("LBA Count: {}", *lbas);
-  // TODO tell the port its sector size.
-}
-
 DmaReadCommand::DmaReadCommand(uint64_t lba, uint64_t sector_cnt,
                                uint64_t paddr)
     : lba_(lba), sector_cnt_(sector_cnt), paddr_(paddr) {}

sys/denali/ahci/command.h

@@ -8,6 +8,13 @@
 
 class AhciPort;
 
+struct CommandInfo {
+  uint8_t command;
+  uint64_t lba;
+  uint16_t sectors;
+  uint64_t paddr;
+};
+
 class Command {
  public:
   Command() = default;
@@ -16,21 +23,6 @@ class Command {
   virtual void PopulatePrdt(PhysicalRegionDescriptor* prdt) const = 0;
 };
 
-class IdentifyDeviceCommand : public Command {
- public:
-  IdentifyDeviceCommand(AhciPort* port) : port_(port) {}
-  virtual void PopulateFis(uint8_t* command_fis) const override;
-  virtual void PopulatePrdt(PhysicalRegionDescriptor* prdt) const override;
-
-  void OnComplete();
-
- private:
-  AhciPort* port_;
-  uint64_t paddr_;
-  mmth::OwnedMemoryRegion identify_ =
-      mmth::OwnedMemoryRegion::ContiguousPhysical(0x200, &paddr_);
-};
-
 class DmaReadCommand : public Command {
  public:
   DmaReadCommand(uint64_t lba, uint64_t sector_cnt, uint64_t dest_paddr);