drivers/firmware/efi/apple-properties.c

Source file repositories/reference/linux-study-clean/drivers/firmware/efi/apple-properties.c

File Facts

System
Linux kernel
Corpus path
drivers/firmware/efi/apple-properties.c
Extension
.c
Size
6102 bytes
Lines
237
Domain
Driver Families
Bucket
drivers/firmware
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct dev_header {
	u32 len;
	u32 prop_count;
	struct efi_dev_path path[];
	/*
	 * followed by key/value pairs, each key and value preceded by u32 len,
	 * len includes itself, value may be empty (in which case its len is 4)
	 */
};

struct properties_header {
	u32 len;
	u32 version;
	u32 dev_count;
	struct dev_header dev_header[];
};

static void __init unmarshal_key_value_pairs(struct dev_header *dev_header,
					     struct device *dev, const void *ptr,
					     struct property_entry entry[])
{
	int i;

	for (i = 0; i < dev_header->prop_count; i++) {
		int remaining = dev_header->len - (ptr - (void *)dev_header);
		u32 key_len, val_len, entry_len;
		const u8 *entry_data;
		char *key;

		if (sizeof(key_len) > remaining)
			break;

		key_len = *(typeof(key_len) *)ptr;
		if (key_len + sizeof(val_len) > remaining ||
		    key_len < sizeof(key_len) + sizeof(efi_char16_t) ||
		    *(efi_char16_t *)(ptr + sizeof(key_len)) == 0) {
			dev_err(dev, "invalid property name len at %#zx\n",
				ptr - (void *)dev_header);
			break;
		}

		val_len = *(typeof(val_len) *)(ptr + key_len);
		if (key_len + val_len > remaining ||
		    val_len < sizeof(val_len)) {
			dev_err(dev, "invalid property val len at %#zx\n",
				ptr - (void *)dev_header + key_len);
			break;
		}

		/* 4 bytes to accommodate UTF-8 code points + null byte */
		key = kzalloc((key_len - sizeof(key_len)) * 4 + 1, GFP_KERNEL);
		if (!key) {
			dev_err(dev, "cannot allocate property name\n");
			break;
		}
		ucs2_as_utf8(key, ptr + sizeof(key_len),
			     key_len - sizeof(key_len));

		entry_data = ptr + key_len + sizeof(val_len);
		entry_len = val_len - sizeof(val_len);
		if (entry_len)
			entry[i] = PROPERTY_ENTRY_U8_ARRAY_LEN(key, entry_data,
							       entry_len);
		else
			entry[i] = PROPERTY_ENTRY_BOOL(key);

		if (dump_properties) {
			dev_info(dev, "property: %s\n", key);
			print_hex_dump(KERN_INFO, pr_fmt(), DUMP_PREFIX_OFFSET,
				16, 1, entry_data, entry_len, true);
		}

		ptr += key_len + val_len;
	}

	if (i != dev_header->prop_count) {
		dev_err(dev, "got %d device properties, expected %u\n", i,
			dev_header->prop_count);
		print_hex_dump(KERN_ERR, pr_fmt(), DUMP_PREFIX_OFFSET,
			16, 1, dev_header, dev_header->len, true);
		return;
	}

	dev_info(dev, "assigning %d device properties\n", i);
}

static int __init unmarshal_devices(struct properties_header *properties)
{
	size_t offset = offsetof(struct properties_header, dev_header[0]);

Annotation

Implementation Notes