[pci] Modularise PCI device support

Some operating environments require (or at least prefer) that we do
not perform our own PCI bus scan, but deal only with specified
devices.  Modularise the PCI core to allow for this.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/bus/pci.c

 }
 
 /**
- * Probe a PCI device
+ * Read PCI device configuration
  *
  * @v pci		PCI device
  * @ret rc		Return status code
+ */
+int pci_read_config ( struct pci_device *pci ) {
+	uint32_t tmp;
+
+	/* Check for physical device presence */
+	pci_read_config_dword ( pci, PCI_VENDOR_ID, &tmp );
+	if ( ( tmp == 0xffffffff ) || ( tmp == 0 ) )
+		return -ENODEV;
+
+	/* Populate struct pci_device */
+	pci->vendor = ( tmp & 0xffff );
+	pci->device = ( tmp >> 16 );
+	pci_read_config_dword ( pci, PCI_REVISION, &tmp );
+	pci->class = ( tmp >> 8 );
+	pci_read_config_byte ( pci, PCI_INTERRUPT_LINE, &pci->irq );
+	pci_read_bases ( pci );
+
+	/* Initialise generic device component */
+	snprintf ( pci->dev.name, sizeof ( pci->dev.name ),
+		   "PCI%02x:%02x.%x", PCI_BUS ( pci->busdevfn ),
+		   PCI_SLOT ( pci->busdevfn ), PCI_FUNC ( pci->busdevfn ) );
+	pci->dev.desc.bus_type = BUS_TYPE_PCI;
+	pci->dev.desc.location = pci->busdevfn;
+	pci->dev.desc.vendor = pci->vendor;
+	pci->dev.desc.device = pci->device;
+	pci->dev.desc.class = pci->class;
+	pci->dev.desc.ioaddr = pci->ioaddr;
+	pci->dev.desc.irq = pci->irq;
+	INIT_LIST_HEAD ( &pci->dev.siblings );
+	INIT_LIST_HEAD ( &pci->dev.children );
+
+	return 0;
+}
+
+/**
+ * Find driver for PCI device
  *
- * Searches for a driver for the PCI device.  If a driver is found,
- * its probe() routine is called.
+ * @v pci		PCI device
+ * @ret rc		Return status code
  */
-static int pci_probe ( struct pci_device *pci ) {
+int pci_find_driver ( struct pci_device *pci ) {
 	struct pci_driver *driver;
 	struct pci_device_id *id;
 	unsigned int i;
-	int rc;
-
-	DBGC ( pci, PCI_FMT " is %04x:%04x mem %lx io %lx irq %d\n",
-	       PCI_ARGS ( pci ), pci->vendor, pci->device, pci->membase,
-	       pci->ioaddr, pci->irq );
 
 	for_each_table_entry ( driver, PCI_DRIVERS ) {
 		for ( i = 0 ; i < driver->id_count ; i++ ) {
 			if ( ( id->device != PCI_ANY_ID ) &&
 			     ( id->device != pci->device ) )
 				continue;
-			pci->driver = driver;
-			pci->id = id;
-			DBGC ( pci, "...using driver %s\n", pci->id->name );
-			if ( ( rc = driver->probe ( pci ) ) != 0 ) {
-				DBGC ( pci, "......probe failed: %s\n",
-				       strerror ( rc ) );
-				continue;
-			}
-			DBGC ( pci, PCI_FMT " added\n", PCI_ARGS ( pci ) );
+			pci_set_driver ( pci, driver, id );
 			return 0;
 		}
 	}
+	return -ENOENT;
+}
 
-	DBGC ( pci, "...no driver found\n" );
-	return -ENOTTY;
+/**
+ * Probe a PCI device
+ *
+ * @v pci		PCI device
+ * @ret rc		Return status code
+ *
+ * Searches for a driver for the PCI device.  If a driver is found,
+ * its probe() routine is called.
+ */
+int pci_probe ( struct pci_device *pci ) {
+	int rc;
+
+	DBGC ( pci, PCI_FMT " (%04x:%04x) has driver \"%s\"\n",
+	       PCI_ARGS ( pci ), pci->vendor, pci->device, pci->id->name );
+	DBGC ( pci, PCI_FMT " has mem %lx io %lx irq %d\n",
+	       PCI_ARGS ( pci ), pci->membase, pci->ioaddr, pci->irq );
+
+	if ( ( rc = pci->driver->probe ( pci ) ) != 0 ) {
+		DBGC ( pci, PCI_FMT " probe failed: %s\n",
+		       PCI_ARGS ( pci ), strerror ( rc ) );
+		return rc;
+	}
+
+	return 0;
 }
 
 /**
  *
  * @v pci		PCI device
  */
-static void pci_remove ( struct pci_device *pci ) {
+void pci_remove ( struct pci_device *pci ) {
 	pci->driver->remove ( pci );
 	DBGC ( pci, PCI_FMT " removed\n", PCI_ARGS ( pci ) );
 }
 	unsigned int num_bus;
 	unsigned int busdevfn;
 	uint8_t hdrtype = 0;
-	uint32_t tmp;
 	int rc;
 
 	num_bus = pci_num_bus();
 			goto err;
 		}
 		memset ( pci, 0, sizeof ( *pci ) );
-		pci->busdevfn = busdevfn;
+		pci_init ( pci, busdevfn );
 			
 		/* Skip all but the first function on
 		 * non-multifunction cards
 			continue;
 		}
 
-		/* Check for physical device presence */
-		pci_read_config_dword ( pci, PCI_VENDOR_ID, &tmp );
-		if ( ( tmp == 0xffffffff ) || ( tmp == 0 ) )
+		/* Read device configuration */
+		if ( ( rc = pci_read_config ( pci ) ) != 0 )
 			continue;
-			
-		/* Populate struct pci_device */
-		pci->vendor = ( tmp & 0xffff );
-		pci->device = ( tmp >> 16 );
-		pci_read_config_dword ( pci, PCI_REVISION, &tmp );
-		pci->class = ( tmp >> 8 );
-		pci_read_config_byte ( pci, PCI_INTERRUPT_LINE,
-				       &pci->irq );
-		pci_read_bases ( pci );
+
+		/* Look for a driver */
+		if ( ( rc = pci_find_driver ( pci ) ) != 0 ) {
+			DBGC ( pci, PCI_FMT " (%04x:%04x) has no driver\n",
+			       PCI_ARGS ( pci ), pci->vendor, pci->device );
+			continue;
+		}
 
 		/* Add to device hierarchy */
-		snprintf ( pci->dev.name, sizeof ( pci->dev.name ),
-			   "PCI%02x:%02x.%x", PCI_BUS ( busdevfn ),
-			   PCI_SLOT ( busdevfn ), PCI_FUNC ( busdevfn ) );
-		pci->dev.desc.bus_type = BUS_TYPE_PCI;
-		pci->dev.desc.location = pci->busdevfn;
-		pci->dev.desc.vendor = pci->vendor;
-		pci->dev.desc.device = pci->device;
-		pci->dev.desc.class = pci->class;
-		pci->dev.desc.ioaddr = pci->ioaddr;
-		pci->dev.desc.irq = pci->irq;
 		pci->dev.parent = &rootdev->dev;
 		list_add ( &pci->dev.siblings, &rootdev->dev.children);
-		INIT_LIST_HEAD ( &pci->dev.children );
 
 		/* Look for a driver */
-		if ( pci_probe ( pci ) == 0 ) {
+		if ( ( rc = pci_probe ( pci ) ) == 0 ) {
 			/* pcidev registered, we can drop our ref */
 			pci = NULL;
 		} else {

src/include/ipxe/pci.h

 extern void adjust_pci_device ( struct pci_device *pci );
 extern unsigned long pci_bar_start ( struct pci_device *pci,
 				     unsigned int reg );
+extern int pci_read_config ( struct pci_device *pci );
+extern int pci_find_driver ( struct pci_device *pci );
+extern int pci_probe ( struct pci_device *pci );
+extern void pci_remove ( struct pci_device *pci );
 extern int pci_find_capability ( struct pci_device *pci, int capability );
 extern unsigned long pci_bar_size ( struct pci_device *pci, unsigned int reg );
 
+/**
+ * Initialise PCI device
+ *
+ * @v pci		PCI device
+ * @v busdevfn		PCI bus:dev.fn address
+ */
+static inline void pci_init ( struct pci_device *pci, unsigned int busdevfn ) {
+	pci->busdevfn = busdevfn;
+}
+
+/**
+ * Set PCI driver
+ *
+ * @v pci		PCI device
+ * @v driver		PCI driver
+ * @v id		PCI device ID
+ */
+static inline void pci_set_driver ( struct pci_device *pci,
+				    struct pci_driver *driver,
+				    struct pci_device_id *id ) {
+	pci->driver = driver;
+	pci->id = id;
+}
+
 /**
  * Set PCI driver-private data
  *