2  * dev-path-parser.c - EFI Device Path parser
35 	if (adev->pnp.unique_id)  in match_acpi_dev()
36 		return !strcmp(adev->pnp.unique_id, hid_uid.uid);  in match_acpi_dev()
41 static long __init parse_acpi_path(struct efi_dev_path *node,  in parse_acpi_path()  argument
42 				   struct device *parent, struct device **child)  in parse_acpi_path()  argument
47 	if (node->length != 12)  in parse_acpi_path()
48 		return -EINVAL;  in parse_acpi_path()
51 		'A' + ((node->acpi.hid >> 10) & 0x1f) - 1,  in parse_acpi_path()
52 		'A' + ((node->acpi.hid >>  5) & 0x1f) - 1,  in parse_acpi_path()
53 		'A' + ((node->acpi.hid >>  0) & 0x1f) - 1,  in parse_acpi_path()
54 			node->acpi.hid >> 16);  in parse_acpi_path()
55 	sprintf(hid_uid.uid, "%u", node->acpi.uid);  in parse_acpi_path()
57 	*child = bus_find_device(&acpi_bus_type, NULL, &hid_uid,  in parse_acpi_path()
59 	if (!*child)  in parse_acpi_path()
60 		return -ENODEV;  in parse_acpi_path()
62 	phys_dev = acpi_get_first_physical_node(to_acpi_device(*child));  in parse_acpi_path()
65 		put_device(*child);  in parse_acpi_path()
66 		*child = phys_dev;  in parse_acpi_path()
76 	return dev_is_pci(dev) && to_pci_dev(dev)->devfn == devfn;  in match_pci_dev()
79 static long __init parse_pci_path(struct efi_dev_path *node,  in parse_pci_path()  argument
80 				  struct device *parent, struct device **child)  in parse_pci_path()  argument
84 	if (node->length != 6)  in parse_pci_path()
85 		return -EINVAL;  in parse_pci_path()
87 		return -EINVAL;  in parse_pci_path()
89 	devfn = PCI_DEVFN(node->pci.dev, node->pci.fn);  in parse_pci_path()
91 	*child = device_find_child(parent, &devfn, match_pci_dev);  in parse_pci_path()
92 	if (!*child)  in parse_pci_path()
93 		return -ENODEV;  in parse_pci_path()
99  * Insert parsers for further node types here.
101  * Each parser takes a pointer to the @node and to the @parent (will be NULL
102  * for the first device path node). If a device corresponding to @node was
104  * device returned in @child.
111  * Be sure to validate the node length and contents before commencing the
115 static long __init parse_end_path(struct efi_dev_path *node,  in parse_end_path()  argument
116 				  struct device *parent, struct device **child)  in parse_end_path()  argument
118 	if (node->length != 4)  in parse_end_path()
119 		return -EINVAL;  in parse_end_path()
120 	if (node->sub_type != EFI_DEV_END_INSTANCE &&  in parse_end_path()
121 	    node->sub_type != EFI_DEV_END_ENTIRE)  in parse_end_path()
122 		return -EINVAL;  in parse_end_path()
124 		return -ENODEV;  in parse_end_path()
126 	*child = get_device(parent);  in parse_end_path()
127 	return node->sub_type;  in parse_end_path()
131  * efi_get_device_by_path - find device by EFI Device Path
132  * @node: EFI Device Path
135  * Parse a series of EFI Device Path nodes at @node and find the corresponding
138  * put_device() after use.  The @node pointer is updated to point to the
139  * location immediately after the "End of Hardware Device Path" node.
144  * If a Device Path node is malformed or its corresponding device is not found,
145  * @node is updated to point to this offending node and an ERR_PTR is returned.
150  *	while (!IS_ERR_OR_NULL(dev = efi_get_device_by_path(&node, &len))) {
162  *	%ERR_PTR(-ENODEV) if no device was found,
163  *	%ERR_PTR(-EINVAL) if a node is malformed or exceeds @len,
164  *	%ERR_PTR(-ENOTSUPP) if support for a node type is not yet implemented.
166 struct device * __init efi_get_device_by_path(struct efi_dev_path **node,  in efi_get_device_by_path()  argument
169 	struct device *parent = NULL, *child;  in efi_get_device_by_path()  local
176 		if (*len < 4 || *len < (*node)->length)  in efi_get_device_by_path()
177 			ret = -EINVAL;  in efi_get_device_by_path()
178 		else if ((*node)->type     == EFI_DEV_ACPI &&  in efi_get_device_by_path()
179 			 (*node)->sub_type == EFI_DEV_BASIC_ACPI)  in efi_get_device_by_path()
180 			ret = parse_acpi_path(*node, parent, &child);  in efi_get_device_by_path()
181 		else if ((*node)->type     == EFI_DEV_HW &&  in efi_get_device_by_path()
182 			 (*node)->sub_type == EFI_DEV_PCI)  in efi_get_device_by_path()
183 			ret = parse_pci_path(*node, parent, &child);  in efi_get_device_by_path()
184 		else if (((*node)->type    == EFI_DEV_END_PATH ||  in efi_get_device_by_path()
185 			  (*node)->type    == EFI_DEV_END_PATH2))  in efi_get_device_by_path()
186 			ret = parse_end_path(*node, parent, &child);  in efi_get_device_by_path()
188 			ret = -ENOTSUPP;  in efi_get_device_by_path()
194 		parent = child;  in efi_get_device_by_path()
195 		*node  = (void *)*node + (*node)->length;  in efi_get_device_by_path()
196 		*len  -= (*node)->length;  in efi_get_device_by_path()
202 	return child;  in efi_get_device_by_path()