[efi] Split efi_usb_path() out to a separate function

Provide efi_usb_path() as a standalone function, to allow for reuse by
the USB mass storage driver.

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

4 files changed, 89 insertions, 54 deletions

diff --git a/src/include/ipxe/efi/efi_path.h b/src/include/ipxe/efi/efi_path.h
index 0d5b902e5..c1d53e764 100644
--- a/src/include/ipxe/efi/efi_path.h
+++ b/src/include/ipxe/efi/efi_path.h
@@ -13,9 +13,12 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <ipxe/efi/efi.h>
 #include <ipxe/efi/Protocol/DevicePath.h>
 
+struct usb_function;
+
 extern EFI_DEVICE_PATH_PROTOCOL *
 efi_path_end ( EFI_DEVICE_PATH_PROTOCOL *path );
 extern size_t efi_path_len ( EFI_DEVICE_PATH_PROTOCOL *path );
+extern EFI_DEVICE_PATH_PROTOCOL * efi_usb_path ( struct usb_function *func );
 
 extern EFI_DEVICE_PATH_PROTOCOL * efi_describe ( struct interface *interface );
 #define efi_describe_TYPE( object_type ) \
diff --git a/src/include/ipxe/efi/efi_usb.h b/src/include/ipxe/efi/efi_usb.h
index 41d9cc665..06baff529 100644
--- a/src/include/ipxe/efi/efi_usb.h
+++ b/src/include/ipxe/efi/efi_usb.h
@@ -17,10 +17,8 @@
 struct efi_usb_device {
 	/** Name */
 	const char *name;
-	/** The underlying USB device */
-	struct usb_device *usb;
-	/** The underlying EFI device */
-	struct efi_device *efidev;
+	/** The underlying USB function */
+	struct usb_function *func;
 	/** Configuration descriptor */
 	struct usb_configuration_descriptor *config;
 	/** Supported languages */
diff --git a/src/interface/efi/efi_path.c b/src/interface/efi/efi_path.c
index fa4306020..162400a0f 100644
--- a/src/interface/efi/efi_path.c
+++ b/src/interface/efi/efi_path.c
@@ -17,7 +17,11 @@
  * 02110-1301, USA.
  */
 
+#include <stdlib.h>
+#include <string.h>
+#include <ipxe/usb.h>
 #include <ipxe/efi/efi.h>
+#include <ipxe/efi/efi_driver.h>
 #include <ipxe/efi/efi_path.h>
 
 /** @file
@@ -57,6 +61,62 @@ size_t efi_path_len ( EFI_DEVICE_PATH_PROTOCOL *path ) {
 }
 
 /**
+ * Construct EFI device path for USB function
+ *
+ * @v func		USB function
+ * @ret path		EFI device path, or NULL on error
+ *
+ * The caller is responsible for eventually calling free() on the
+ * allocated device path.
+ */
+EFI_DEVICE_PATH_PROTOCOL * efi_usb_path ( struct usb_function *func ) {
+	struct usb_device *usb = func->usb;
+	struct efi_device *efidev;
+	EFI_DEVICE_PATH_PROTOCOL *path;
+	EFI_DEVICE_PATH_PROTOCOL *end;
+	USB_DEVICE_PATH *usbpath;
+	unsigned int count;
+	size_t prefix_len;
+	size_t len;
+
+	/* Sanity check */
+	assert ( func->desc.count >= 1 );
+
+	/* Find parent EFI device */
+	efidev = efidev_parent ( &func->dev );
+	if ( ! efidev )
+		return NULL;
+
+	/* Calculate device path length */
+	count = ( usb_depth ( usb ) + 1 );
+	prefix_len = efi_path_len ( efidev->path );
+	len = ( prefix_len + ( count * sizeof ( *usbpath ) ) +
+		sizeof ( *end ) );
+
+	/* Allocate device path */
+	path = zalloc ( len );
+	if ( ! path )
+		return NULL;
+
+	/* Construct device path */
+	memcpy ( path, efidev->path, prefix_len );
+	end = ( ( ( void * ) path ) + len - sizeof ( *end ) );
+	end->Type = END_DEVICE_PATH_TYPE;
+	end->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
+	end->Length[0] = sizeof ( *end );
+	usbpath = ( ( ( void * ) end ) - sizeof ( *usbpath ) );
+	usbpath->InterfaceNumber = func->interface[0];
+	for ( ; usb ; usbpath--, usb = usb->port->hub->usb ) {
+		usbpath->Header.Type = MESSAGING_DEVICE_PATH;
+		usbpath->Header.SubType = MSG_USB_DP;
+		usbpath->Header.Length[0] = sizeof ( *usbpath );
+		usbpath->ParentPortNumber = ( usb->port->address - 1 );
+	}
+
+	return path;
+}
+
+/**
  * Describe object as an EFI device path
  *
  * @v intf		Interface
diff --git a/src/interface/efi/efi_usb.c b/src/interface/efi/efi_usb.c
index 7ffeb7ffa..55b5bc880 100644
--- a/src/interface/efi/efi_usb.c
+++ b/src/interface/efi/efi_usb.c
@@ -73,10 +73,10 @@ static const char * efi_usb_direction_name ( EFI_USB_DATA_DIRECTION direction ){
 static VOID EFIAPI efi_usb_timer ( EFI_EVENT event __unused,
 				   VOID *context ) {
 	struct efi_usb_endpoint *usbep = context;
-	struct usb_bus *bus = usbep->usbintf->usbdev->usb->port->hub->bus;
+	struct usb_function *func = usbep->usbintf->usbdev->func;
 
 	/* Poll bus */
-	usb_poll ( bus );
+	usb_poll ( func->usb->port->hub->bus );
 
 	/* Refill endpoint */
 	if ( usbep->ep.open )
@@ -179,7 +179,7 @@ static int efi_usb_open ( struct efi_usb_interface *usbintf,
 	}
 
 	/* Allocate and initialise structure */
-	usb_endpoint_init ( &usbep->ep, usbdev->usb, driver );
+	usb_endpoint_init ( &usbep->ep, usbdev->func->usb, driver );
 	usb_endpoint_describe ( &usbep->ep, endpoint, attributes, mtu, 0,
 				( interval << 3 /* microframes */ ) );
 
@@ -354,7 +354,7 @@ static int efi_usb_sync_transfer ( struct efi_usb_interface *usbintf,
 	for ( i = 0 ; ( ( timeout == 0 ) || ( i < timeout ) ) ; i++ ) {
 
 		/* Poll bus */
-		usb_poll ( usbdev->usb->port->hub->bus );
+		usb_poll ( usbdev->func->usb->port->hub->bus );
 
 		/* Check for completion */
 		if ( usbep->rc != -EINPROGRESS ) {
@@ -594,7 +594,7 @@ efi_usb_control_transfer ( EFI_USB_IO_PROTOCOL *usbio,
 		efi_usb_close_all ( usbintf );
 
 	/* Issue control transfer */
-	if ( ( rc = usb_control ( usbdev->usb, request, value, index,
+	if ( ( rc = usb_control ( usbdev->func->usb, request, value, index,
 				  data, len ) ) != 0 ) {
 		DBGC ( usbdev, "USBDEV %s control %04x:%04x:%04x:%04x %p+%zx "
 		       "failed: %s\n", usbintf->name, request, value, index,
@@ -841,7 +841,7 @@ efi_usb_get_device_descriptor ( EFI_USB_IO_PROTOCOL *usbio,
 	DBGC2 ( usbdev, "USBDEV %s get device descriptor\n", usbintf->name );
 
 	/* Copy cached device descriptor */
-	memcpy ( efidesc, &usbdev->usb->device, sizeof ( *efidesc ) );
+	memcpy ( efidesc, &usbdev->func->usb->device, sizeof ( *efidesc ) );
 
 	return 0;
 }
@@ -972,8 +972,9 @@ efi_usb_get_string_descriptor ( EFI_USB_IO_PROTOCOL *usbio, UINT16 language,
 	saved_tpl = bs->RaiseTPL ( TPL_CALLBACK );
 
 	/* Read descriptor header */
-	if ( ( rc = usb_get_descriptor ( usbdev->usb, 0, USB_STRING_DESCRIPTOR,
-					 index, language, &header,
+	if ( ( rc = usb_get_descriptor ( usbdev->func->usb, 0,
+					 USB_STRING_DESCRIPTOR, index,
+					 language, &header,
 					 sizeof ( header ) ) ) != 0 ) {
 		DBGC ( usbdev, "USBDEV %s could not get string %d:%d "
 		       "descriptor header: %s\n", usbintf->name, language,
@@ -996,9 +997,9 @@ efi_usb_get_string_descriptor ( EFI_USB_IO_PROTOCOL *usbio, UINT16 language,
 	}
 
 	/* Read whole descriptor */
-	if ( ( rc = usb_get_descriptor ( usbdev->usb, 0, USB_STRING_DESCRIPTOR,
-					 index, language, buffer,
-					 len ) ) != 0 ) {
+	if ( ( rc = usb_get_descriptor ( usbdev->func->usb, 0,
+					 USB_STRING_DESCRIPTOR, index,
+					 language, buffer, len ) ) != 0 ) {
 		DBGC ( usbdev, "USBDEV %s could not get string %d:%d "
 		       "descriptor: %s\n", usbintf->name, language,
 		       index, strerror ( rc ) );
@@ -1107,25 +1108,13 @@ static EFI_USB_IO_PROTOCOL efi_usb_io_protocol = {
 static int efi_usb_install ( struct efi_usb_device *usbdev,
 			     unsigned int interface ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-	struct efi_device *efidev = usbdev->efidev;
+	struct usb_function *func = usbdev->func;
 	struct efi_usb_interface *usbintf;
-	struct usb_device *usb;
-	EFI_DEVICE_PATH_PROTOCOL *path_end;
-	USB_DEVICE_PATH *usbpath;
-	unsigned int path_count;
-	size_t path_prefix_len;
-	size_t path_len;
 	EFI_STATUS efirc;
 	int rc;
 
-	/* Calculate device path length */
-	path_count = ( usb_depth ( usbdev->usb ) + 1 );
-	path_prefix_len = efi_path_len ( efidev->path );
-	path_len = ( path_prefix_len + ( path_count * sizeof ( *usbpath ) ) +
-		     sizeof ( *path_end ) );
-
 	/* Allocate and initialise structure */
-	usbintf = zalloc ( sizeof ( *usbintf ) + path_len );
+	usbintf = zalloc ( sizeof ( *usbintf ) );
 	if ( ! usbintf ) {
 		rc = -ENOMEM;
 		goto err_alloc;
@@ -1136,22 +1125,12 @@ static int efi_usb_install ( struct efi_usb_device *usbdev,
 	usbintf->interface = interface;
 	memcpy ( &usbintf->usbio, &efi_usb_io_protocol,
 		 sizeof ( usbintf->usbio ) );
-	usbintf->path = ( ( ( void * ) usbintf ) + sizeof ( *usbintf ) );
 
 	/* Construct device path */
-	memcpy ( usbintf->path, efidev->path, path_prefix_len );
-	path_end = ( ( ( void * ) usbintf->path ) + path_len -
-		     sizeof ( *path_end ) );
-	path_end->Type = END_DEVICE_PATH_TYPE;
-	path_end->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
-	path_end->Length[0] = sizeof ( *path_end );
-	usbpath = ( ( ( void * ) path_end ) - sizeof ( *usbpath ) );
-	usbpath->InterfaceNumber = interface;
-	for ( usb = usbdev->usb ; usb ; usbpath--, usb = usb->port->hub->usb ) {
-		usbpath->Header.Type = MESSAGING_DEVICE_PATH;
-		usbpath->Header.SubType = MSG_USB_DP;
-		usbpath->Header.Length[0] = sizeof ( *usbpath );
-		usbpath->ParentPortNumber = ( usb->port->address - 1 );
+	usbintf->path = efi_usb_path ( func );
+	if ( ! usbintf->path ) {
+		rc = -ENODEV;
+		goto err_path;
 	}
 
 	/* Add to list of interfaces */
@@ -1182,6 +1161,8 @@ static int efi_usb_install ( struct efi_usb_device *usbdev,
 	efi_usb_close_all ( usbintf );
 	efi_usb_free_all ( usbintf );
 	list_del ( &usbintf->list );
+	free ( usbintf->path );
+ err_path:
 	free ( usbintf );
  err_alloc:
 	return rc;
@@ -1219,6 +1200,9 @@ static void efi_usb_uninstall ( struct efi_usb_interface *usbintf ) {
 	/* Remove from list of interfaces */
 	list_del ( &usbintf->list );
 
+	/* Free device path */
+	free ( usbintf->path );
+
 	/* Free interface */
 	free ( usbintf );
 }
@@ -1252,7 +1236,6 @@ static int efi_usb_probe ( struct usb_function *func,
 	struct usb_device *usb = func->usb;
 	struct efi_usb_device *usbdev;
 	struct efi_usb_interface *usbintf;
-	struct efi_device *efidev;
 	struct usb_descriptor_header header;
 	struct usb_descriptor_header *lang;
 	size_t config_len;
@@ -1260,13 +1243,6 @@ static int efi_usb_probe ( struct usb_function *func,
 	unsigned int i;
 	int rc;
 
-	/* Find parent EFI device */
-	efidev = efidev_parent ( &func->dev );
-	if ( ! efidev ) {
-		rc = -ENOTTY;
-		goto err_no_efidev;
-	}
-
 	/* Get configuration length */
 	config_len = le16_to_cpu ( config->len );
 
@@ -1288,8 +1264,7 @@ static int efi_usb_probe ( struct usb_function *func,
 	}
 	usb_func_set_drvdata ( func, usbdev );
 	usbdev->name = func->name;
-	usbdev->usb = usb;
-	usbdev->efidev = efidev;
+	usbdev->func = func;
 	usbdev->config = ( ( ( void * ) usbdev ) + sizeof ( *usbdev ) );
 	memcpy ( usbdev->config, config, config_len );
 	lang = ( ( ( void * ) usbdev->config ) + config_len );
@@ -1325,7 +1300,6 @@ static int efi_usb_probe ( struct usb_function *func,
  err_get_languages:
 	free ( usbdev );
  err_alloc:
- err_no_efidev:
 	return rc;
 }