pci: change offset type to uint16 in config space API.

* The config space is larger than 255, we need to use an uint16 to access
offsets superior or equal to 256. The current API only proposes an uint8 for this.
This change switches the offset parameter to the uint16 type. Axel hinted that
the used values are the same with such a change (the doc says sign extended to 2 or
4 bytes).
I checked with GCC2 and it's indeed the case when inspecting the memory.
With GCC4, instructions are the same on function call.
* prints info about extended capabilities.
* struct pci_module_info and struct pci_device_module_info are extended with
pci_find_extended_capability().

headers/os/drivers/PCI.h

@@ -131,18 +131,18 @@ struct pci_module_info {
 						pci_info 	*info	/* caller-supplied buffer for info */
 					);
 	uint32			(*read_pci_config) (
-						uchar	bus,		/* bus number */
-						uchar	device,		/* device # on bus */
-						uchar	function,	/* function # in device */
-						uchar	offset,		/* offset in configuration space */
-						uchar	size		/* # bytes to read (1, 2 or 4) */
+						uint8	bus,		/* bus number */
+						uint8	device,		/* device # on bus */
+						uint8	function,	/* function # in device */
+						uint16	offset,		/* offset in configuration space */
+						uint8	size		/* # bytes to read (1, 2 or 4) */
 					);
 	void			(*write_pci_config) (
-						uchar	bus,		/* bus number */
-						uchar	device,		/* device # on bus */
-						uchar	function,	/* function # in device */
-						uchar	offset,		/* offset in configuration space */
-						uchar	size,		/* # bytes to write (1, 2 or 4) */
+						uint8	bus,		/* bus number */
+						uint8	device,		/* device # on bus */
+						uint8	function,	/* function # in device */
+						uint16	offset,		/* offset in configuration space */
+						uint8	size,		/* # bytes to write (1, 2 or 4) */
 						uint32	value		/* value to write */
 					);
 
@@ -174,6 +174,14 @@ struct pci_module_info {
 						uchar device,
 						uchar function,
 						uchar newInterruptLineValue);
+
+	status_t		(*find_pci_extended_capability) (
+						uint8	bus,
+						uint8	device,
+						uint8	function,
+						uint16	cap_id,
+						uint16	*offset
+					);
 };
 
 #define	B_PCI_MODULE_NAME		"bus_managers/pci/v1"

headers/os/drivers/bus/PCI.h

@@ -27,13 +27,15 @@ typedef struct pci_device_module_info {
 
 	void	*(*ram_address)(pci_device *device, const void *physicalAddress);
 
-	uint32	(*read_pci_config)(pci_device *device, uint8 offset,
+	uint32	(*read_pci_config)(pci_device *device, uint16 offset,
 				uint8 size);
-	void	(*write_pci_config)(pci_device *device, uint8 offset,
+	void	(*write_pci_config)(pci_device *device, uint16 offset,
 				uint8 size, uint32 value);
 	status_t (*find_pci_capability)(pci_device *device, uint8 capID,
 				uint8 *offset);
 	void 	(*get_pci_info)(pci_device *device, struct pci_info *info);
+	status_t (*find_pci_extended_capability)(pci_device *device, uint16 capID,
+				uint16 *offset);
 } pci_device_module_info;