efi/dev-path-parser: Add struct definition for vendor type device path nodes

In preparation of adding support for loading the initrd via a special
device path, add the struct definition of a vendor GUIDed device path
node to efi.h.

Since we will be producing these data structures rather than just
consumsing the ones instantiated by the firmware, refactor the various
device path node definitions so we can take the size of each node using
sizeof() rather than having to resort to opaque arithmetic in the static
initializers.

While at it, drop the #if IS_ENABLED() check for the declaration of
efi_get_device_by_path(), which is unnecessary, and constify its first
argument as well.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

1 files changed, 19 insertions, 19 deletions

diff --git a/drivers/firmware/efi/dev-path-parser.c b/drivers/firmware/efi/dev-path-parser.c
index 20123384271c..5c9625e552f4 100644
--- a/drivers/firmware/efi/dev-path-parser.c
+++ b/drivers/firmware/efi/dev-path-parser.c
@@ -31,13 +31,13 @@ static int __init match_acpi_dev(struct device *dev, const void *data)
 		return !strcmp("0", hid_uid.uid);
 }
 
-static long __init parse_acpi_path(struct efi_dev_path *node,
+static long __init parse_acpi_path(const struct efi_dev_path *node,
 				   struct device *parent, struct device **child)
 {
 	struct acpi_hid_uid hid_uid = {};
 	struct device *phys_dev;
 
-	if (node->length != 12)
+	if (node->header.length != 12)
 		return -EINVAL;
 
 	sprintf(hid_uid.hid[0].id, "%c%c%c%04X",
@@ -69,12 +69,12 @@ static int __init match_pci_dev(struct device *dev, void *data)
 	return dev_is_pci(dev) && to_pci_dev(dev)->devfn == devfn;
 }
 
-static long __init parse_pci_path(struct efi_dev_path *node,
+static long __init parse_pci_path(const struct efi_dev_path *node,
 				  struct device *parent, struct device **child)
 {
 	unsigned int devfn;
 
-	if (node->length != 6)
+	if (node->header.length != 6)
 		return -EINVAL;
 	if (!parent)
 		return -EINVAL;
@@ -105,19 +105,19 @@ static long __init parse_pci_path(struct efi_dev_path *node,
  * search for a device.
  */
 
-static long __init parse_end_path(struct efi_dev_path *node,
+static long __init parse_end_path(const struct efi_dev_path *node,
 				  struct device *parent, struct device **child)
 {
-	if (node->length != 4)
+	if (node->header.length != 4)
 		return -EINVAL;
-	if (node->sub_type != EFI_DEV_END_INSTANCE &&
-	    node->sub_type != EFI_DEV_END_ENTIRE)
+	if (node->header.sub_type != EFI_DEV_END_INSTANCE &&
+	    node->header.sub_type != EFI_DEV_END_ENTIRE)
 		return -EINVAL;
 	if (!parent)
 		return -ENODEV;
 
 	*child = get_device(parent);
-	return node->sub_type;
+	return node->header.sub_type;
 }
 
 /**
@@ -156,7 +156,7 @@ static long __init parse_end_path(struct efi_dev_path *node,
  *	%ERR_PTR(-EINVAL) if a node is malformed or exceeds @len,
  *	%ERR_PTR(-ENOTSUPP) if support for a node type is not yet implemented.
  */
-struct device * __init efi_get_device_by_path(struct efi_dev_path **node,
+struct device * __init efi_get_device_by_path(const struct efi_dev_path **node,
 					      size_t *len)
 {
 	struct device *parent = NULL, *child;
@@ -166,16 +166,16 @@ struct device * __init efi_get_device_by_path(struct efi_dev_path **node,
 		return NULL;
 
 	while (!ret) {
-		if (*len < 4 || *len < (*node)->length)
+		if (*len < 4 || *len < (*node)->header.length)
 			ret = -EINVAL;
-		else if ((*node)->type     == EFI_DEV_ACPI &&
-			 (*node)->sub_type == EFI_DEV_BASIC_ACPI)
+		else if ((*node)->header.type		== EFI_DEV_ACPI &&
+			 (*node)->header.sub_type	== EFI_DEV_BASIC_ACPI)
 			ret = parse_acpi_path(*node, parent, &child);
-		else if ((*node)->type     == EFI_DEV_HW &&
-			 (*node)->sub_type == EFI_DEV_PCI)
+		else if ((*node)->header.type		== EFI_DEV_HW &&
+			 (*node)->header.sub_type	== EFI_DEV_PCI)
 			ret = parse_pci_path(*node, parent, &child);
-		else if (((*node)->type    == EFI_DEV_END_PATH ||
-			  (*node)->type    == EFI_DEV_END_PATH2))
+		else if (((*node)->header.type		== EFI_DEV_END_PATH ||
+			  (*node)->header.type		== EFI_DEV_END_PATH2))
 			ret = parse_end_path(*node, parent, &child);
 		else
 			ret = -ENOTSUPP;
@@ -185,8 +185,8 @@ struct device * __init efi_get_device_by_path(struct efi_dev_path **node,
 			return ERR_PTR(ret);
 
 		parent = child;
-		*node  = (void *)*node + (*node)->length;
-		*len  -= (*node)->length;
+		*node  = (void *)*node + (*node)->header.length;
+		*len  -= (*node)->header.length;
 	}
 
 	if (ret == EFI_DEV_END_ENTIRE)