diff options
| -rw-r--r-- | drivers/firmware/google/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/firmware/google/Makefile | 3 | ||||
| -rw-r--r-- | drivers/firmware/google/vpd.c | 332 |
3 files changed, 342 insertions, 0 deletions
diff --git a/drivers/firmware/google/Kconfig b/drivers/firmware/google/Kconfig index 00000e0376b9..f16b381a569c 100644 --- a/drivers/firmware/google/Kconfig +++ b/drivers/firmware/google/Kconfig @@ -64,4 +64,11 @@ config GOOGLE_MEMCONSOLE_COREBOOT the coreboot table. If found, this log is exported to userland in the file /sys/firmware/log. +config GOOGLE_VPD + tristate "Vital Product Data" + depends on GOOGLE_COREBOOT_TABLE + help + This option enables the kernel to expose the content of Google VPD + under /sys/firmware/vpd. + endif # GOOGLE_FIRMWARE diff --git a/drivers/firmware/google/Makefile b/drivers/firmware/google/Makefile index bb952c686d3b..bc4de02202ad 100644 --- a/drivers/firmware/google/Makefile +++ b/drivers/firmware/google/Makefile @@ -6,3 +6,6 @@ obj-$(CONFIG_GOOGLE_COREBOOT_TABLE_OF) += coreboot_table-of.o obj-$(CONFIG_GOOGLE_MEMCONSOLE) += memconsole.o obj-$(CONFIG_GOOGLE_MEMCONSOLE_COREBOOT) += memconsole-coreboot.o obj-$(CONFIG_GOOGLE_MEMCONSOLE_X86_LEGACY) += memconsole-x86-legacy.o + +vpd-sysfs-y := vpd.o vpd_decode.o +obj-$(CONFIG_GOOGLE_VPD) += vpd-sysfs.o diff --git a/drivers/firmware/google/vpd.c b/drivers/firmware/google/vpd.c new file mode 100644 index 000000000000..619f4bae474f --- /dev/null +++ b/drivers/firmware/google/vpd.c @@ -0,0 +1,332 @@ +/* + * vpd.c + * + * Driver for exporting VPD content to sysfs. + * + * Copyright 2017 Google Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License v2.0 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/ctype.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/kobject.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/sysfs.h> + +#include "coreboot_table.h" +#include "vpd_decode.h" + +#define CB_TAG_VPD 0x2c +#define VPD_CBMEM_MAGIC 0x43524f53 + +static struct kobject *vpd_kobj; + +struct vpd_cbmem { + u32 magic; + u32 version; + u32 ro_size; + u32 rw_size; + u8 blob[0]; +}; + +struct vpd_section { + bool enabled; + const char *name; + char *raw_name; /* the string name_raw */ + struct kobject *kobj; /* vpd/name directory */ + char *baseaddr; + struct bin_attribute bin_attr; /* vpd/name_raw bin_attribute */ + struct list_head attribs; /* key/value in vpd_attrib_info list */ +}; + +struct vpd_attrib_info { + char *key; + const char *value; + struct bin_attribute bin_attr; + struct list_head list; +}; + +static struct vpd_section ro_vpd; +static struct vpd_section rw_vpd; + +static ssize_t vpd_attrib_read(struct file *filp, struct kobject *kobp, + struct bin_attribute *bin_attr, char *buf, + loff_t pos, size_t count) +{ + struct vpd_attrib_info *info = bin_attr->private; + + return memory_read_from_buffer(buf, count, &pos, info->value, + info->bin_attr.size); +} + +/* + * vpd_section_check_key_name() + * + * The VPD specification supports only [a-zA-Z0-9_]+ characters in key names but + * old firmware versions may have entries like "S/N" which are problematic when + * exporting them as sysfs attributes. These keys present in old firmwares are + * ignored. + * + * Returns VPD_OK for a valid key name, VPD_FAIL otherwise. + * + * @key: The key name to check + * @key_len: key name length + */ +static int vpd_section_check_key_name(const u8 *key, s32 key_len) +{ + int c; + + while (key_len-- > 0) { + c = *key++; + + if (!isalnum(c) && c != '_') + return VPD_FAIL; + } + + return VPD_OK; +} + +static int vpd_section_attrib_add(const u8 *key, s32 key_len, + const u8 *value, s32 value_len, + void *arg) +{ + int ret; + struct vpd_section *sec = arg; + struct vpd_attrib_info *info; + + /* + * Return VPD_OK immediately to decode next entry if the current key + * name contains invalid characters. + */ + if (vpd_section_check_key_name(key, key_len) != VPD_OK) + return VPD_OK; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + info->key = kzalloc(key_len + 1, GFP_KERNEL); + if (!info->key) + return -ENOMEM; + + memcpy(info->key, key, key_len); + + sysfs_bin_attr_init(&info->bin_attr); + info->bin_attr.attr.name = info->key; + info->bin_attr.attr.mode = 0444; + info->bin_attr.size = value_len; + info->bin_attr.read = vpd_attrib_read; + info->bin_attr.private = info; + + info->value = value; + + INIT_LIST_HEAD(&info->list); + list_add_tail(&info->list, &sec->attribs); + + ret = sysfs_create_bin_file(sec->kobj, &info->bin_attr); + if (ret) { + kfree(info->key); + return ret; + } + + return 0; +} + +static void vpd_section_attrib_destroy(struct vpd_section *sec) +{ + struct vpd_attrib_info *info; + struct vpd_attrib_info *temp; + + list_for_each_entry_safe(info, temp, &sec->attribs, list) { + kfree(info->key); + sysfs_remove_bin_file(sec->kobj, &info->bin_attr); + kfree(info); + } +} + +static ssize_t vpd_section_read(struct file *filp, struct kobject *kobp, + struct bin_attribute *bin_attr, char *buf, + loff_t pos, size_t count) +{ + struct vpd_section *sec = bin_attr->private; + + return memory_read_from_buffer(buf, count, &pos, sec->baseaddr, + sec->bin_attr.size); +} + +static int vpd_section_create_attribs(struct vpd_section *sec) +{ + s32 consumed; + int ret; + + consumed = 0; + do { + ret = vpd_decode_string(sec->bin_attr.size, sec->baseaddr, + &consumed, vpd_section_attrib_add, sec); + } while (ret == VPD_OK); + + return 0; +} + +static int vpd_section_init(const char *name, struct vpd_section *sec, + phys_addr_t physaddr, size_t size) +{ + int ret; + int raw_len; + + sec->baseaddr = memremap(physaddr, size, MEMREMAP_WB); + if (!sec->baseaddr) + return -ENOMEM; + + sec->name = name; + + /* We want to export the raw partion with name ${name}_raw */ + raw_len = strlen(name) + 5; + sec->raw_name = kzalloc(raw_len, GFP_KERNEL); + strncpy(sec->raw_name, name, raw_len); + strncat(sec->raw_name, "_raw", raw_len); + + sysfs_bin_attr_init(&sec->bin_attr); + sec->bin_attr.attr.name = sec->raw_name; + sec->bin_attr.attr.mode = 0444; + sec->bin_attr.size = size; + sec->bin_attr.read = vpd_section_read; + sec->bin_attr.private = sec; + + ret = sysfs_create_bin_file(vpd_kobj, &sec->bin_attr); + if (ret) + goto free_sec; + + sec->kobj = kobject_create_and_add(name, vpd_kobj); + if (!sec->kobj) { + ret = -EINVAL; + goto sysfs_remove; + } + + INIT_LIST_HEAD(&sec->attribs); + vpd_section_create_attribs(sec); + + sec->enabled = true; + + return 0; + +sysfs_remove: + sysfs_remove_bin_file(vpd_kobj, &sec->bin_attr); + +free_sec: + kfree(sec->raw_name); + iounmap(sec->baseaddr); + + return ret; +} + +static int vpd_section_destroy(struct vpd_section *sec) +{ + if (sec->enabled) { + vpd_section_attrib_destroy(sec); + kobject_del(sec->kobj); + sysfs_remove_bin_file(vpd_kobj, &sec->bin_attr); + kfree(sec->raw_name); + iounmap(sec->baseaddr); + } + + return 0; +} + +static int vpd_sections_init(phys_addr_t physaddr) +{ + struct vpd_cbmem __iomem *temp; + struct vpd_cbmem header; + int ret = 0; + + temp = memremap(physaddr, sizeof(struct vpd_cbmem), MEMREMAP_WB); + if (!temp) + return -ENOMEM; + + memcpy_fromio(&header, temp, sizeof(struct vpd_cbmem)); + iounmap(temp); + + if (header.magic != VPD_CBMEM_MAGIC) + return -ENODEV; + + if (header.ro_size) { + ret = vpd_section_init("ro", &ro_vpd, + physaddr + sizeof(struct vpd_cbmem), + header.ro_size); + if (ret) + return ret; + } + + if (header.rw_size) { + ret = vpd_section_init("rw", &rw_vpd, + physaddr + sizeof(struct vpd_cbmem) + + header.ro_size, header.rw_size); + if (ret) + return ret; + } + + return 0; +} + +static int vpd_probe(struct platform_device *pdev) +{ + int ret; + struct lb_cbmem_ref entry; + + ret = coreboot_table_find(CB_TAG_VPD, &entry, sizeof(entry)); + if (ret) + return ret; + + return vpd_sections_init(entry.cbmem_addr); +} + +static struct platform_driver vpd_driver = { + .probe = vpd_probe, + .driver = { + .name = "vpd", + }, +}; + +static int __init vpd_platform_init(void) +{ + struct platform_device *pdev; + + pdev = platform_device_register_simple("vpd", -1, NULL, 0); + if (!pdev) + return -ENODEV; + + vpd_kobj = kobject_create_and_add("vpd", firmware_kobj); + if (!vpd_kobj) + return -ENOMEM; + + memset(&ro_vpd, 0, sizeof(ro_vpd)); + memset(&rw_vpd, 0, sizeof(rw_vpd)); + + platform_driver_register(&vpd_driver); + + return 0; +} + +static void __exit vpd_platform_exit(void) +{ + vpd_section_destroy(&ro_vpd); + vpd_section_destroy(&rw_vpd); + kobject_del(vpd_kobj); +} + +module_init(vpd_platform_init); +module_exit(vpd_platform_exit); + +MODULE_AUTHOR("Google, Inc."); +MODULE_LICENSE("GPL"); |