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efi/dev-path-parser: Add struct definition for vendor type device pat…
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…h 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>
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Ard Biesheuvel committed Feb 23, 2020
1 parent a570b06 commit db8952e
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Showing 3 changed files with 52 additions and 42 deletions.
8 changes: 4 additions & 4 deletions drivers/firmware/efi/apple-properties.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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)) {
Expand All @@ -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;
Expand Down
38 changes: 19 additions & 19 deletions drivers/firmware/efi/dev-path-parser.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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",
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
}

/**
Expand Down Expand Up @@ -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;
Expand All @@ -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;
Expand All @@ -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)
Expand Down
48 changes: 29 additions & 19 deletions include/linux/efi.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)
{
Expand Down

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