text: /*
   * Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
   *
   * SPDX-License-Identifier: BSD-2-Clause
   */
  
  #include <Kernel/Debug.h>
  #include <Kernel/IO.h>
  #include <Kernel/PCI/IOAccess.h>
  
  namespace Kernel {
  namespace PCI {
  
  UNMAP_AFTER_INIT void IOAccess::initialize()
  {
      if (!Access::is_initialized()) {
          new IOAccess();
          dbgln_if(PCI_DEBUG, "PCI: IO access initialised.");
      }
  }
  
  UNMAP_AFTER_INIT IOAccess::IOAccess()
  {
      dmesgln("PCI: Using I/O instructions for PCI configuration space access");
      enumerate_hardware([&](const Address& address, ID id) {
          m_physical_ids.append({ address, id, get_capabilities(address) });
      });
  }
  
  u8 IOAccess::read8_field(Address address, u32 field)
  {
      dbgln_if(PCI_DEBUG, "PCI: IO Reading 8-bit field {:#08x} for {}", field, address);
      return Access::early_read8_field(address, field);
  }
  
  u16 IOAccess::read16_field(Address address, u32 field)
  {
      dbgln_if(PCI_DEBUG, "PCI: IO Reading 16-bit field {:#08x} for {}", field, address);
      return Access::early_read16_field(address, field);
  }
  
  u32 IOAccess::read32_field(Address address, u32 field)
  {
      dbgln_if(PCI_DEBUG, "PCI: IO Reading 32-bit field {:#08x} for {}", field, address);
      return Access::early_read32_field(address, field);
  }
  
  void IOAccess::write8_field(Address address, u32 field, u8 value)
  {
      dbgln_if(PCI_DEBUG, "PCI: IO Writing to 8-bit field {:#08x}, value={:#02x} for {}", field, value, address);
      IO::out32(PCI_ADDRESS_PORT, address.io_address_for_field(field));
      IO::out8(PCI_VALUE_PORT + (field & 3), value);
  }
  void IOAccess::write16_field(Address address, u32 field, u16 value)
  {
      dbgln_if(PCI_DEBUG, "PCI: IO Writing to 16-bit field {:#08x}, value={:#02x} for {}", field, value, address);
      IO::out32(PCI_ADDRESS_PORT, address.io_address_for_field(field));
      IO::out16(PCI_VALUE_PORT + (field & 2), value);
  }
  void IOAccess::write32_field(Address address, u32 field, u32 value)
  {
      dbgln_if(PCI_DEBUG, "PCI: IO Writing to 32-bit field {:#08x}, value={:#02x} for {}", field, value, address);
      IO::out32(PCI_ADDRESS_PORT, address.io_address_for_field(field));
      IO::out32(PCI_VALUE_PORT, value);
  }
  
  void IOAccess::enumerate_hardware(Function<void(Address, ID)> callback)
  {
  #if PCI_DEBUG
      dbgln("PCI: IO enumerating hardware");
  #endif
      // Single PCI host controller.
      if ((read8_field(Address(), PCI_HEADER_TYPE) & 0x80) == 0) {
          enumerate_bus(-1, 0, callback, true);
          return;
      }
  
      // Multiple PCI host controllers.
      for (int bus = 0; bus < 256; ++bus) {
          if (read16_field(Address(0, 0, 0, bus), PCI_VENDOR_ID) == PCI_NONE)
              break;
          enumerate_bus(-1, bus, callback, false);
      }
  }
  
  }
  }
  