text: #ifndef _IPXE_PCI_IO_H
  #define _IPXE_PCI_IO_H
  
  /** @file
   *
   * PCI I/O API
   *
   */
  
  FILE_LICENCE ( GPL2_OR_LATER );
  
  #include <stdint.h>
  #include <ipxe/api.h>
  #include <config/ioapi.h>
  
  /**
   * Calculate static inline PCI I/O API function name
   *
   * @v _prefix		Subsystem prefix
   * @v _api_func		API function
   * @ret _subsys_func	Subsystem API function
   */
  #define PCIAPI_INLINE( _subsys, _api_func ) \
  	SINGLE_API_INLINE ( PCIAPI_PREFIX_ ## _subsys, _api_func )
  
  /**
   * Provide a PCI I/O API implementation
   *
   * @v _prefix		Subsystem prefix
   * @v _api_func		API function
   * @v _func		Implementing function
   */
  #define PROVIDE_PCIAPI( _subsys, _api_func, _func ) \
  	PROVIDE_SINGLE_API ( PCIAPI_PREFIX_ ## _subsys, _api_func, _func )
  
  /**
   * Provide a static inline PCI I/O API implementation
   *
   * @v _prefix		Subsystem prefix
   * @v _api_func		API function
   */
  #define PROVIDE_PCIAPI_INLINE( _subsys, _api_func ) \
  	PROVIDE_SINGLE_API_INLINE ( PCIAPI_PREFIX_ ## _subsys, _api_func )
  
  /* Include all architecture-independent I/O API headers */
  #include <ipxe/efi/efi_pci_api.h>
  #include <ipxe/linux/linux_pci.h>
  
  /* Include all architecture-dependent I/O API headers */
  #include <bits/pci_io.h>
  
  /**
   * Determine number of PCI buses within system
   *
   * @ret num_bus		Number of buses
   */
  int pci_num_bus ( void );
  
  /**
   * Read byte from PCI configuration space
   *
   * @v pci	PCI device
   * @v where	Location within PCI configuration space
   * @v value	Value read
   * @ret rc	Return status code
   */
  int pci_read_config_byte ( struct pci_device *pci, unsigned int where,
  			   uint8_t *value );
  
  /**
   * Read 16-bit word from PCI configuration space
   *
   * @v pci	PCI device
   * @v where	Location within PCI configuration space
   * @v value	Value read
   * @ret rc	Return status code
   */
  int pci_read_config_word ( struct pci_device *pci, unsigned int where,
  			   uint16_t *value );
  
  /**
   * Read 32-bit dword from PCI configuration space
   *
   * @v pci	PCI device
   * @v where	Location within PCI configuration space
   * @v value	Value read
   * @ret rc	Return status code
   */
  int pci_read_config_dword ( struct pci_device *pci, unsigned int where,
  			    uint32_t *value );
  
  /**
   * Write byte to PCI configuration space
   *
   * @v pci	PCI device
   * @v where	Location within PCI configuration space
   * @v value	Value to be written
   * @ret rc	Return status code
   */
  int pci_write_config_byte ( struct pci_device *pci, unsigned int where,
  			    uint8_t value );
  
  /**
   * Write 16-bit word to PCI configuration space
   *
   * @v pci	PCI device
   * @v where	Location within PCI configuration space
   * @v value	Value to be written
   * @ret rc	Return status code
   */
  int pci_write_config_word ( struct pci_device *pci, unsigned int where,
  			    uint16_t value );
  
  /**
   * Write 32-bit dword to PCI configuration space
   *
   * @v pci	PCI device
   * @v where	Location within PCI configuration space
   * @v value	Value to be written
   * @ret rc	Return status code
   */
  int pci_write_config_dword ( struct pci_device *pci, unsigned int where,
  			     uint32_t value );
  
  #endif /* _IPXE_PCI_IO_H */
  