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>

diff --git a/drivers/firmware/efi/apple-properties.c b/drivers/firmware/efi/apple-properties.c
index 084942846f4d1cb5473ec429dc7dbe3f724b949a..34f53d898acb0f9f61c1ff3573d7428be52701df 100644 (file)
--- a/drivers/firmware/efi/apple-properties.c
+++ b/drivers/firmware/efi/apple-properties.c
@@ -46,7 +46,7 @@ struct properties_header {
 };
 
 static void __init unmarshal_key_value_pairs(struct dev_header *dev_header,
-                                            struct device *dev, void *ptr,
+                                            struct device *dev, const void *ptr,
                                             struct property_entry entry[])
 {
        int i;
@@ -117,10 +117,10 @@ static int __init unmarshal_devices(struct properties_header *properties)
        while (offset + sizeof(struct dev_header) < properties->len) {
                struct dev_header *dev_header = (void *)properties + offset;
                struct property_entry *entry = NULL;
+               const struct efi_dev_path *ptr;
                struct device *dev;
                size_t len;
                int ret, i;
-               void *ptr;
 
                if (offset + dev_header->len > properties->len ||
                    dev_header->len <= sizeof(*dev_header)) {
@@ -131,10 +131,10 @@ static int __init unmarshal_devices(struct properties_header *properties)
                ptr = dev_header->path;
                len = dev_header->len - sizeof(*dev_header);
 
-               dev = efi_get_device_by_path((struct efi_dev_path **)&ptr, &len);
+               dev = efi_get_device_by_path(&ptr, &len);
                if (IS_ERR(dev)) {
                        pr_err("device path parse error %ld at %#zx:\n",
-                              PTR_ERR(dev), ptr - (void *)dev_header);
+                              PTR_ERR(dev), (void *)ptr - (void *)dev_header);
                        print_hex_dump(KERN_ERR, pr_fmt(), DUMP_PREFIX_OFFSET,
                               16, 1, dev_header, dev_header->len, true);
                        dev = NULL;

diff --git a/drivers/firmware/efi/dev-path-parser.c b/drivers/firmware/efi/dev-path-parser.c
index 20123384271c8150e969471ee19ac090953207d6..5c9625e552f4f39dedc65deace9fcef051b54596 100644 (file)
--- 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)

diff --git a/include/linux/efi.h b/include/linux/efi.h
index 9ccf313fe9de5cd65f335fde24ae2781b491858d..0976e57b4caac9484eba08de08eabec722aceba8 100644 (file)
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -855,30 +855,40 @@ extern int efi_status_to_err(efi_status_t status);
 #define   EFI_DEV_END_ENTIRE                   0xFF
 
 struct efi_generic_dev_path {
-       u8 type;
-       u8 sub_type;
-       u16 length;
-} __attribute ((packed));
+       u8                              type;
+       u8                              sub_type;
+       u16                             length;
+} __packed;
+
+struct efi_acpi_dev_path {
+       struct efi_generic_dev_path     header;
+       u32                             hid;
+       u32                             uid;
+} __packed;
+
+struct efi_pci_dev_path {
+       struct efi_generic_dev_path     header;
+       u8                              fn;
+       u8                              dev;
+} __packed;
+
+struct efi_vendor_dev_path {
+       struct efi_generic_dev_path     header;
+       efi_guid_t                      vendorguid;
+       u8                              vendordata[];
+} __packed;
 
 struct efi_dev_path {
-       u8 type;        /* can be replaced with unnamed */
-       u8 sub_type;    /* struct efi_generic_dev_path; */
-       u16 length;     /* once we've moved to -std=c11 */
        union {
-               struct {
-                       u32 hid;
-                       u32 uid;
-               } acpi;
-               struct {
-                       u8 fn;
-                       u8 dev;
-               } pci;
+               struct efi_generic_dev_path     header;
+               struct efi_acpi_dev_path        acpi;
+               struct efi_pci_dev_path         pci;
+               struct efi_vendor_dev_path      vendor;
        };
-} __attribute ((packed));
+} __packed;
 
-#if IS_ENABLED(CONFIG_EFI_DEV_PATH_PARSER)
-struct device *efi_get_device_by_path(struct efi_dev_path **node, size_t *len);
-#endif
+struct device *efi_get_device_by_path(const struct efi_dev_path **node,
+                                     size_t *len);
 
 static inline void memrange_efi_to_native(u64 *addr, u64 *npages)
 {