233 строки
5.9 KiB
C
233 строки
5.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* apple-properties.c - EFI device properties on Macs
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* Copyright (C) 2016 Lukas Wunner <lukas@wunner.de>
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*
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* Note, all properties are considered as u8 arrays.
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* To get a value of any of them the caller must use device_property_read_u8_array().
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*/
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#define pr_fmt(fmt) "apple-properties: " fmt
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#include <linux/memblock.h>
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#include <linux/efi.h>
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#include <linux/io.h>
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#include <linux/platform_data/x86/apple.h>
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#include <linux/property.h>
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#include <linux/slab.h>
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#include <linux/ucs2_string.h>
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#include <asm/setup.h>
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static bool dump_properties __initdata;
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static int __init dump_properties_enable(char *arg)
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{
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dump_properties = true;
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return 0;
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}
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__setup("dump_apple_properties", dump_properties_enable);
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struct dev_header {
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u32 len;
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u32 prop_count;
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struct efi_dev_path path[];
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/*
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* followed by key/value pairs, each key and value preceded by u32 len,
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* len includes itself, value may be empty (in which case its len is 4)
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*/
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};
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struct properties_header {
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u32 len;
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u32 version;
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u32 dev_count;
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struct dev_header dev_header[];
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};
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static void __init unmarshal_key_value_pairs(struct dev_header *dev_header,
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struct device *dev, const void *ptr,
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struct property_entry entry[])
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{
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int i;
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for (i = 0; i < dev_header->prop_count; i++) {
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int remaining = dev_header->len - (ptr - (void *)dev_header);
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u32 key_len, val_len, entry_len;
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const u8 *entry_data;
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char *key;
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if (sizeof(key_len) > remaining)
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break;
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key_len = *(typeof(key_len) *)ptr;
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if (key_len + sizeof(val_len) > remaining ||
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key_len < sizeof(key_len) + sizeof(efi_char16_t) ||
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*(efi_char16_t *)(ptr + sizeof(key_len)) == 0) {
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dev_err(dev, "invalid property name len at %#zx\n",
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ptr - (void *)dev_header);
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break;
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}
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val_len = *(typeof(val_len) *)(ptr + key_len);
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if (key_len + val_len > remaining ||
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val_len < sizeof(val_len)) {
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dev_err(dev, "invalid property val len at %#zx\n",
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ptr - (void *)dev_header + key_len);
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break;
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}
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/* 4 bytes to accommodate UTF-8 code points + null byte */
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key = kzalloc((key_len - sizeof(key_len)) * 4 + 1, GFP_KERNEL);
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if (!key) {
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dev_err(dev, "cannot allocate property name\n");
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break;
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}
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ucs2_as_utf8(key, ptr + sizeof(key_len),
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key_len - sizeof(key_len));
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entry_data = ptr + key_len + sizeof(val_len);
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entry_len = val_len - sizeof(val_len);
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entry[i] = PROPERTY_ENTRY_U8_ARRAY_LEN(key, entry_data,
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entry_len);
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if (dump_properties) {
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dev_info(dev, "property: %s\n", key);
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print_hex_dump(KERN_INFO, pr_fmt(), DUMP_PREFIX_OFFSET,
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16, 1, entry_data, entry_len, true);
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}
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ptr += key_len + val_len;
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}
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if (i != dev_header->prop_count) {
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dev_err(dev, "got %d device properties, expected %u\n", i,
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dev_header->prop_count);
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print_hex_dump(KERN_ERR, pr_fmt(), DUMP_PREFIX_OFFSET,
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16, 1, dev_header, dev_header->len, true);
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return;
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}
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dev_info(dev, "assigning %d device properties\n", i);
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}
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static int __init unmarshal_devices(struct properties_header *properties)
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{
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size_t offset = offsetof(struct properties_header, dev_header[0]);
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while (offset + sizeof(struct dev_header) < properties->len) {
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struct dev_header *dev_header = (void *)properties + offset;
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struct property_entry *entry = NULL;
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const struct efi_dev_path *ptr;
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struct device *dev;
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size_t len;
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int ret, i;
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if (offset + dev_header->len > properties->len ||
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dev_header->len <= sizeof(*dev_header)) {
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pr_err("invalid len in dev_header at %#zx\n", offset);
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return -EINVAL;
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}
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ptr = dev_header->path;
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len = dev_header->len - sizeof(*dev_header);
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dev = efi_get_device_by_path(&ptr, &len);
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if (IS_ERR(dev)) {
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pr_err("device path parse error %ld at %#zx:\n",
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PTR_ERR(dev), (void *)ptr - (void *)dev_header);
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print_hex_dump(KERN_ERR, pr_fmt(), DUMP_PREFIX_OFFSET,
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16, 1, dev_header, dev_header->len, true);
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dev = NULL;
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goto skip_device;
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}
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entry = kcalloc(dev_header->prop_count + 1, sizeof(*entry),
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GFP_KERNEL);
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if (!entry) {
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dev_err(dev, "cannot allocate properties\n");
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goto skip_device;
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}
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unmarshal_key_value_pairs(dev_header, dev, ptr, entry);
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if (!entry[0].name)
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goto skip_device;
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ret = device_add_properties(dev, entry); /* makes deep copy */
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if (ret)
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dev_err(dev, "error %d assigning properties\n", ret);
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for (i = 0; entry[i].name; i++)
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kfree(entry[i].name);
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skip_device:
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kfree(entry);
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put_device(dev);
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offset += dev_header->len;
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}
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return 0;
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}
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static int __init map_properties(void)
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{
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struct properties_header *properties;
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struct setup_data *data;
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u32 data_len;
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u64 pa_data;
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int ret;
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if (!x86_apple_machine)
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return 0;
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pa_data = boot_params.hdr.setup_data;
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while (pa_data) {
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data = memremap(pa_data, sizeof(*data), MEMREMAP_WB);
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if (!data) {
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pr_err("cannot map setup_data header\n");
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return -ENOMEM;
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}
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if (data->type != SETUP_APPLE_PROPERTIES) {
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pa_data = data->next;
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memunmap(data);
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continue;
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}
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data_len = data->len;
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memunmap(data);
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data = memremap(pa_data, sizeof(*data) + data_len, MEMREMAP_WB);
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if (!data) {
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pr_err("cannot map setup_data payload\n");
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return -ENOMEM;
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}
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properties = (struct properties_header *)data->data;
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if (properties->version != 1) {
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pr_err("unsupported version:\n");
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print_hex_dump(KERN_ERR, pr_fmt(), DUMP_PREFIX_OFFSET,
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16, 1, properties, data_len, true);
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ret = -ENOTSUPP;
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} else if (properties->len != data_len) {
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pr_err("length mismatch, expected %u\n", data_len);
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print_hex_dump(KERN_ERR, pr_fmt(), DUMP_PREFIX_OFFSET,
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16, 1, properties, data_len, true);
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ret = -EINVAL;
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} else
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ret = unmarshal_devices(properties);
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/*
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* Can only free the setup_data payload but not its header
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* to avoid breaking the chain of ->next pointers.
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*/
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data->len = 0;
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memunmap(data);
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memblock_free_late(pa_data + sizeof(*data), data_len);
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return ret;
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}
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return 0;
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}
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fs_initcall(map_properties);
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