[efi] Include NII driver within "snp" and "snponly" build targets

End users almost certainly don't care whether the underlying interface
is SNP or NII/UNDI.  Try to minimise surprise and unnecessary
documentation by including the NII driver whenever the SNP driver is
requested.

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

src/drivers/net/efi/nii.c

 #include <ipxe/umalloc.h>
 #include <ipxe/efi/efi.h>
 #include <ipxe/efi/efi_driver.h>
-#include <ipxe/efi/efi_snp.h>
 #include <ipxe/efi/efi_pci.h>
 #include <ipxe/efi/efi_utils.h>
+#include <ipxe/efi/Protocol/NetworkInterfaceIdentifier.h>
 #include <ipxe/efi/IndustryStandard/Acpi10.h>
+#include "nii.h"
 
 /** @file
  *
 	.poll = nii_poll,
 };
 
-/**
- * Check to see if driver supports a device
- *
- * @v device		EFI device handle
- * @ret rc		Return status code
- */
-static int nii_supported ( EFI_HANDLE device ) {
-	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-	EFI_STATUS efirc;
-
-	/* Check that this is not a device we are providing ourselves */
-	if ( find_snpdev ( device ) != NULL ) {
-		DBGCP ( device, "NII %p %s is provided by this binary\n",
-			device, efi_handle_name ( device ) );
-		return -ENOTTY;
-	}
-
-	/* Test for presence of NII protocol */
-	if ( ( efirc = bs->OpenProtocol ( device,
-					  &efi_nii31_protocol_guid,
-					  NULL, efi_image_handle, device,
-					  EFI_OPEN_PROTOCOL_TEST_PROTOCOL))!=0){
-		DBGCP ( device, "NII %p %s is not an NII device\n",
-			device, efi_handle_name ( device ) );
-		return -EEFI ( efirc );
-	}
-	DBGC ( device, "NII %p %s is an NII device\n",
-	       device, efi_handle_name ( device ) );
-
-	return 0;
-}
-
 /**
  * Attach driver to device
  *
  * @v efidev		EFI device
  * @ret rc		Return status code
  */
-static int nii_start ( struct efi_device *efidev ) {
+int nii_start ( struct efi_device *efidev ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	EFI_HANDLE device = efidev->device;
 	struct net_device *netdev;
  *
  * @v efidev		EFI device
  */
-static void nii_stop ( struct efi_device *efidev ) {
+void nii_stop ( struct efi_device *efidev ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	struct net_device *netdev = efidev_get_drvdata ( efidev );
 	struct nii_nic *nii = netdev->priv;
 	netdev_nullify ( netdev );
 	netdev_put ( netdev );
 }
-
-/** EFI NII driver */
-struct efi_driver nii_driver __efi_driver ( EFI_DRIVER_NORMAL ) = {
-	.name = "NII",
-	.supported = nii_supported,
-	.start = nii_start,
-	.stop = nii_stop,
-};

src/drivers/net/efi/nii.h

+#ifndef _NII_H
+#define _NII_H
+
+/** @file
+ *
+ * NII driver
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+struct efi_device;
+
+extern int nii_start ( struct efi_device *efidev );
+extern void nii_stop ( struct efi_device *efidev );
+
+#endif /* _NII_H */

src/drivers/net/efi/snp.c

 #include <ipxe/efi/efi_driver.h>
 #include <ipxe/efi/efi_snp.h>
 #include "snpnet.h"
+#include "nii.h"
 
 /** @file
  *
 	return 0;
 }
 
+/**
+ * Check to see if driver supports a device
+ *
+ * @v device		EFI device handle
+ * @ret rc		Return status code
+ */
+static int nii_supported ( EFI_HANDLE device ) {
+	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
+	EFI_STATUS efirc;
+
+	/* Check that this is not a device we are providing ourselves */
+	if ( find_snpdev ( device ) != NULL ) {
+		DBGCP ( device, "NII %p %s is provided by this binary\n",
+			device, efi_handle_name ( device ) );
+		return -ENOTTY;
+	}
+
+	/* Test for presence of NII protocol */
+	if ( ( efirc = bs->OpenProtocol ( device,
+					  &efi_nii31_protocol_guid,
+					  NULL, efi_image_handle, device,
+					  EFI_OPEN_PROTOCOL_TEST_PROTOCOL))!=0){
+		DBGCP ( device, "NII %p %s is not an NII device\n",
+			device, efi_handle_name ( device ) );
+		return -EEFI ( efirc );
+	}
+	DBGC ( device, "NII %p %s is an NII device\n",
+	       device, efi_handle_name ( device ) );
+
+	return 0;
+}
+
 /** EFI SNP driver */
 struct efi_driver snp_driver __efi_driver ( EFI_DRIVER_NORMAL ) = {
 	.name = "SNP",
 	.start = snpnet_start,
 	.stop = snpnet_stop,
 };
+
+/** EFI NII driver */
+struct efi_driver nii_driver __efi_driver ( EFI_DRIVER_NORMAL ) = {
+	.name = "NII",
+	.supported = nii_supported,
+	.start = nii_start,
+	.stop = nii_stop,
+};

src/drivers/net/efi/snponly.c

 
 FILE_LICENCE ( GPL2_OR_LATER );
 
+#include <string.h>
 #include <errno.h>
 #include <ipxe/init.h>
 #include <ipxe/efi/efi.h>
 #include <ipxe/efi/efi_driver.h>
+#include <ipxe/efi/efi_utils.h>
 #include <ipxe/efi/Protocol/SimpleNetwork.h>
+#include <ipxe/efi/Protocol/NetworkInterfaceIdentifier.h>
 #include "snpnet.h"
+#include "nii.h"
 
 /** @file
  *
- * SNP chainloading-device-only driver
+ * EFI chainloaded-device-only driver
  *
  */
 
+/** A chainloaded protocol */
+struct chained_protocol {
+	/** Protocol GUID */
+	EFI_GUID *protocol;
+	/**
+	 * Protocol instance installed on the loaded image's device handle
+	 *
+	 * We match against the protocol instance (rather than simply
+	 * matching against the device handle itself) because some
+	 * systems load us via a child of the underlying device, with
+	 * a duplicate protocol installed on the child handle.
+	 */
+	void *interface;
+};
+
+/** Chainloaded SNP protocol */
+static struct chained_protocol chained_snp = {
+	.protocol = &efi_simple_network_protocol_guid,
+};
+
+/** Chainloaded NII protocol */
+static struct chained_protocol chained_nii = {
+	.protocol = &efi_nii31_protocol_guid,
+};
+
 /**
- * SNP protocol instance installed on the loaded image's device handle
+ * Locate chainloaded protocol instance
  *
- * We match against the SNP protocol instance (rather than simply
- * matching against the device handle itself) because some systems
- * load us via a child of the SNP device, with a duplicate SNP
- * protocol installed on the child handle.
+ * @v chained		Chainloaded protocol
+ * @ret rc		Return status code
  */
-static EFI_SIMPLE_NETWORK_PROTOCOL *snponly;
+static int chained_locate ( struct chained_protocol *chained ) {
+	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
+	EFI_HANDLE device = efi_loaded_image->DeviceHandle;
+	EFI_HANDLE parent;
+	EFI_STATUS efirc;
+	int rc;
+
+	/* Locate handle supporting this protocol */
+	if ( ( rc = efi_locate_device ( device, chained->protocol,
+					&parent ) ) != 0 ) {
+		DBGC ( device, "CHAINED %p %s does not support %s: %s\n",
+		       device, efi_handle_name ( device ),
+		       efi_guid_ntoa ( chained->protocol ), strerror ( rc ) );
+		goto err_locate_device;
+	}
+	DBGC ( device, "CHAINED %p %s found %s on ", device,
+	       efi_handle_name ( device ), efi_guid_ntoa ( chained->protocol ));
+	DBGC ( device, "%p %s\n", parent, efi_handle_name ( parent ) );
+
+	/* Get protocol instance */
+	if ( ( efirc = bs->OpenProtocol ( parent, chained->protocol,
+					  &chained->interface, efi_image_handle,
+					  device,
+					  EFI_OPEN_PROTOCOL_GET_PROTOCOL ))!=0){
+		rc = -EEFI ( efirc );
+		DBGC ( device, "CHAINED %p %s could not open %s on ",
+		       device, efi_handle_name ( device ),
+		       efi_guid_ntoa ( chained->protocol ) );
+		DBGC ( device, "%p %s: %s\n",
+		       parent, efi_handle_name ( parent ), strerror ( rc ) );
+		goto err_open_protocol;
+	}
+
+ err_locate_device:
+	bs->CloseProtocol ( parent, chained->protocol, efi_image_handle,
+			    device );
+ err_open_protocol:
+	return rc;
+}
 
 /**
  * Check to see if driver supports a device
  *
  * @v device		EFI device handle
+ * @v chained		Chainloaded protocol
  * @ret rc		Return status code
  */
-static int snponly_supported ( EFI_HANDLE device ) {
+static int chained_supported ( EFI_HANDLE device,
+			       struct chained_protocol *chained ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	EFI_STATUS efirc;
-	union {
-		EFI_SIMPLE_NETWORK_PROTOCOL *snp;
-		void *interface;
-	} snp;
+	void *interface;
 	int rc;
 
-	/* Get SNP protocol */
-	if ( ( efirc = bs->OpenProtocol ( device,
-					  &efi_simple_network_protocol_guid,
-					  &snp.interface, efi_image_handle,
-					  device,
+	/* Get protocol */
+	if ( ( efirc = bs->OpenProtocol ( device, chained->protocol, &interface,
+					  efi_image_handle, device,
 					  EFI_OPEN_PROTOCOL_GET_PROTOCOL ))!=0){
 		rc = -EEFI ( efirc );
-		DBGCP ( device, "SNPONLY %p %s is not an SNP device\n",
-			device, efi_handle_name ( device ) );
-		goto err_not_snp;
+		DBGCP ( device, "CHAINED %p %s is not a %s device\n",
+			device, efi_handle_name ( device ),
+			efi_guid_ntoa ( chained->protocol ) );
+		goto err_open_protocol;
 	}
 
 	/* Test for a match against the chainloading device */
-	if ( snp.snp != snponly ) {
-		DBGC ( device, "SNPONLY %p %s SNP %p is not the "
-		       "chainloading SNP\n", device,
-		       efi_handle_name ( device ), snp.snp );
+	if ( interface != chained->interface ) {
+		DBGC ( device, "CHAINED %p %s %p is not the chainloaded "
+		       "%s\n", device, efi_handle_name ( device ),
+		       interface, efi_guid_ntoa ( chained->protocol ) );
 		rc = -ENOTTY;
-		goto err_not_snponly;
+		goto err_no_match;
 	}
 
 	/* Success */
 	rc = 0;
-	DBGC ( device, "SNPONLY %p %s SNP %p is the chainloading SNP\n",
-	       device, efi_handle_name ( device ), snp.snp );
+	DBGC ( device, "CHAINED %p %s %p is the chainloaded %s\n",
+	       device, efi_handle_name ( device ), interface,
+	       efi_guid_ntoa ( chained->protocol ) );
 
- err_not_snponly:
-	bs->CloseProtocol ( device, &efi_simple_network_protocol_guid,
-			    efi_image_handle, device );
- err_not_snp:
+ err_no_match:
+	bs->CloseProtocol ( device, chained->protocol, efi_image_handle,
+			    device );
+ err_open_protocol:
 	return rc;
 }
 
-/** EFI chainloading-device-only driver */
+/**
+ * Check to see if driver supports a device
+ *
+ * @v device		EFI device handle
+ * @ret rc		Return status code
+ */
+static int snponly_supported ( EFI_HANDLE device ) {
+
+	return chained_supported ( device, &chained_snp );
+}
+
+/**
+ * Check to see if driver supports a device
+ *
+ * @v device		EFI device handle
+ * @ret rc		Return status code
+ */
+static int niionly_supported ( EFI_HANDLE device ) {
+
+	return chained_supported ( device, &chained_nii );
+}
+
+/** EFI SNP chainloading-device-only driver */
 struct efi_driver snponly_driver __efi_driver ( EFI_DRIVER_NORMAL ) = {
 	.name = "SNPONLY",
 	.supported = snponly_supported,
 	.stop = snpnet_stop,
 };
 
+/** EFI NII chainloading-device-only driver */
+struct efi_driver niionly_driver __efi_driver ( EFI_DRIVER_NORMAL ) = {
+	.name = "NIIONLY",
+	.supported = niionly_supported,
+	.start = nii_start,
+	.stop = nii_stop,
+};
+
 /**
- * Initialise EFI chainloading-device-only driver
+ * Initialise EFI chainloaded-device-only driver
  *
  */
-static void snponly_init ( void ) {
-	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-	EFI_HANDLE device = efi_loaded_image->DeviceHandle;
-	union {
-		EFI_SIMPLE_NETWORK_PROTOCOL *snp;
-		void *interface;
-	} snp;
-	EFI_STATUS efirc;
+static void chained_init ( void ) {
 
-	/* Look for SNP protocol on the loaded image's device handle */
-	if ( ( efirc = bs->OpenProtocol ( device,
-					  &efi_simple_network_protocol_guid,
-					  &snp.interface, efi_image_handle,
-					  device,
-					  EFI_OPEN_PROTOCOL_GET_PROTOCOL ))!=0){
-		DBGC ( device, "SNPONLY %p %s is not an SNP device\n",
-		       device, efi_handle_name ( device ) );
-		goto err_open_protocol;
-	}
-
-	/* Record SNP protocol instance */
-	snponly = snp.snp;
-	DBGC ( device, "SNPONLY %p %s found chainloading SNP %p\n",
-	       device, efi_handle_name ( device ), snponly );
-
- err_open_protocol:
-	bs->CloseProtocol ( device, &efi_simple_network_protocol_guid,
-			    efi_image_handle, device );
+	chained_locate ( &chained_snp );
+	chained_locate ( &chained_nii );
 }
 
-/** EFI chainloading-device-only initialisation function */
-struct init_fn snponly_init_fn __init_fn ( INIT_LATE ) = {
-	.initialise = snponly_init,
+/** EFI chainloaded-device-only initialisation function */
+struct init_fn chained_init_fn __init_fn ( INIT_LATE ) = {
+	.initialise = chained_init,
 };