[pci] Allow pci_find_next() to return non-zero PCI segments

Separate the return status code from the returned PCI bus:dev.fn
address, in order to allow pci_find_next() to be used to find devices
with a non-zero PCI segment number.

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

src/drivers/bus/pci.c

@@ -229,9 +229,10 @@ int pci_read_config ( struct pci_device *pci ) {
  *
  * @v pci		PCI device to fill in
  * @v busdevfn		Starting bus:dev.fn address
- * @ret busdevfn	Bus:dev.fn address of next PCI device, or negative error
+ * @ret busdevfn	Bus:dev.fn address of next PCI device
+ * @ret rc		Return status code
  */
-int pci_find_next ( struct pci_device *pci, unsigned int busdevfn ) {
+int pci_find_next ( struct pci_device *pci, uint32_t *busdevfn ) {
 	static unsigned int end;
 	unsigned int sub_end;
 	uint8_t hdrtype;
@@ -243,11 +244,11 @@ int pci_find_next ( struct pci_device *pci, unsigned int busdevfn ) {
 		end = PCI_BUSDEVFN ( 0, pci_num_bus(), 0, 0 );
 
 	/* Find next PCI device, if any */
-	for ( ; busdevfn < end ; busdevfn++ ) {
+	for ( ; *busdevfn < end ; (*busdevfn)++ ) {
 
 		/* Check for PCI device existence */
 		memset ( pci, 0, sizeof ( *pci ) );
-		pci_init ( pci, busdevfn );
+		pci_init ( pci, *busdevfn );
 		if ( ( rc = pci_read_config ( pci ) ) != 0 )
 			continue;
 
@@ -267,7 +268,7 @@ int pci_find_next ( struct pci_device *pci, unsigned int busdevfn ) {
 		}
 
 		/* Return this device */
-		return busdevfn;
+		return 0;
 	}
 
 	return -ENODEV;
@@ -348,7 +349,7 @@ void pci_remove ( struct pci_device *pci ) {
  */
 static int pcibus_probe ( struct root_device *rootdev ) {
 	struct pci_device *pci = NULL;
-	int busdevfn = 0;
+	uint32_t busdevfn = 0;
 	int rc;
 
 	for ( busdevfn = 0 ; 1 ; busdevfn++ ) {
@@ -362,8 +363,7 @@ static int pcibus_probe ( struct root_device *rootdev ) {
 		}
 
 		/* Find next PCI device, if any */
-		busdevfn = pci_find_next ( pci, busdevfn );
+		if ( ( rc = pci_find_next ( pci, &busdevfn ) ) != 0 )
-		if ( busdevfn < 0 )
 			break;
 
 		/* Look for a driver */

src/hci/commands/pci_cmd.c

@@ -58,7 +58,7 @@ static int pciscan_exec ( int argc, char **argv ) {
 	struct named_setting setting;
 	struct pci_device pci;
 	unsigned long prev;
-	int next;
+	uint32_t busdevfn;
 	int len;
 	int rc;
 
@@ -75,17 +75,15 @@ static int pciscan_exec ( int argc, char **argv ) {
 	if ( ( len = fetchn_setting ( setting.settings, &setting.setting,
 				      NULL, &setting.setting, &prev ) ) < 0 ) {
 		/* Setting not yet defined: start searching from 00:00.0 */
-		prev = 0;
+		busdevfn = 0;
 	} else {
 		/* Setting is defined: start searching from next location */
-		prev++;
+		busdevfn = ( prev + 1 );
 	}
 
 	/* Find next existent PCI device */
-	if ( ( next = pci_find_next ( &pci, prev ) ) < 0 ) {
+	if ( ( rc = pci_find_next ( &pci, &busdevfn ) ) != 0 )
-		rc = next;
 		goto err_find_next;
-	}
 
 	/* Apply default type if necessary.  Use ":uint16" rather than
 	 * ":busdevfn" to allow for easy inclusion within a
@@ -96,7 +94,7 @@ static int pciscan_exec ( int argc, char **argv ) {
 
 	/* Store setting */
 	if ( ( rc = storen_setting ( setting.settings, &setting.setting,
-				     next ) ) != 0 ) {
+				     busdevfn ) ) != 0 ) {
 		printf ( "Could not store \"%s\": %s\n",
 			 setting.setting.name, strerror ( rc ) );
 		goto err_store;

src/include/ipxe/pci.h

@@ -301,7 +301,7 @@ 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_next ( struct pci_device *pci, unsigned int busdevfn );
+extern int pci_find_next ( struct pci_device *pci, uint32_t *busdevfn );
 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 );