// SPDX-License-Identifier: GPL-2.0-only /* * dmi-sysfs.c * * This module exports the DMI tables read-only to userspace through the * sysfs file system. * * Data is currently found below * /sys/firmware/dmi/... * * DMI attributes are presented in attribute files with names * formatted using %d-%d, so that the first integer indicates the * structure type (0-255), and the second field is the instance of that * entry. * * Copyright 2011 Google, Inc. */ #include <linux/kernel.h> #include <linux/init.h> #include <linux/module.h> #include <linux/types.h> #include <linux/kobject.h> #include <linux/dmi.h> #include <linux/capability.h> #include <linux/slab.h> #include <linux/list.h> #include <linux/io.h> #include <asm/dmi.h> #define MAX_ENTRY_TYPE … struct dmi_sysfs_entry { … }; /* * Global list of dmi_sysfs_entry. Even though this should only be * manipulated at setup and teardown, the lazy nature of the kobject * system means we get lazy removes. */ static LIST_HEAD(entry_list); static DEFINE_SPINLOCK(entry_list_lock); /* dmi_sysfs_attribute - Top level attribute. used by all entries. */ struct dmi_sysfs_attribute { … }; #define DMI_SYSFS_ATTR(_entry, _name) … /* * dmi_sysfs_mapped_attribute - Attribute where we require the entry be * mapped in. Use in conjunction with dmi_sysfs_specialize_attr_ops. */ struct dmi_sysfs_mapped_attribute { … }; #define DMI_SYSFS_MAPPED_ATTR(_entry, _name) … /************************************************* * Generic DMI entry support. *************************************************/ static void dmi_entry_free(struct kobject *kobj) { … } static struct dmi_sysfs_entry *to_entry(struct kobject *kobj) { … } static struct dmi_sysfs_attribute *to_attr(struct attribute *attr) { … } static ssize_t dmi_sysfs_attr_show(struct kobject *kobj, struct attribute *_attr, char *buf) { … } static const struct sysfs_ops dmi_sysfs_attr_ops = …; dmi_callback; struct find_dmi_data { … }; static void find_dmi_entry_helper(const struct dmi_header *dh, void *_data) { … } /* State for passing the read parameters through dmi_find_entry() */ struct dmi_read_state { … }; static ssize_t find_dmi_entry(struct dmi_sysfs_entry *entry, dmi_callback callback, void *private) { … } /* * Calculate and return the byte length of the dmi entry identified by * dh. This includes both the formatted portion as well as the * unformatted string space, including the two trailing nul characters. */ static size_t dmi_entry_length(const struct dmi_header *dh) { … } /************************************************* * Support bits for specialized DMI entry support *************************************************/ struct dmi_entry_attr_show_data { … }; static ssize_t dmi_entry_attr_show_helper(struct dmi_sysfs_entry *entry, const struct dmi_header *dh, void *_data) { … } static ssize_t dmi_entry_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) { … } static const struct sysfs_ops dmi_sysfs_specialize_attr_ops = …; /************************************************* * Specialized DMI entry support. *************************************************/ /*** Type 15 - System Event Table ***/ #define DMI_SEL_ACCESS_METHOD_IO8 … #define DMI_SEL_ACCESS_METHOD_IO2x8 … #define DMI_SEL_ACCESS_METHOD_IO16 … #define DMI_SEL_ACCESS_METHOD_PHYS32 … #define DMI_SEL_ACCESS_METHOD_GPNV … struct dmi_system_event_log { … } __packed; #define DMI_SYSFS_SEL_FIELD(_field) … DMI_SYSFS_SEL_FIELD(…); DMI_SYSFS_SEL_FIELD(…); DMI_SYSFS_SEL_FIELD(…); DMI_SYSFS_SEL_FIELD(…); DMI_SYSFS_SEL_FIELD(…); DMI_SYSFS_SEL_FIELD(…); DMI_SYSFS_SEL_FIELD(…); DMI_SYSFS_SEL_FIELD(…); DMI_SYSFS_SEL_FIELD(…); DMI_SYSFS_SEL_FIELD(…); static struct attribute *dmi_sysfs_sel_attrs[] = …; ATTRIBUTE_GROUPS(…); static const struct kobj_type dmi_system_event_log_ktype = …; #ifdef CONFIG_HAS_IOPORT sel_io_reader; static DEFINE_MUTEX(io_port_lock); static u8 read_sel_8bit_indexed_io(const struct dmi_system_event_log *sel, loff_t offset) { … } static u8 read_sel_2x8bit_indexed_io(const struct dmi_system_event_log *sel, loff_t offset) { … } static u8 read_sel_16bit_indexed_io(const struct dmi_system_event_log *sel, loff_t offset) { … } static sel_io_reader sel_io_readers[] = …; static ssize_t dmi_sel_raw_read_io(struct dmi_sysfs_entry *entry, const struct dmi_system_event_log *sel, char *buf, loff_t pos, size_t count) { … } #endif static ssize_t dmi_sel_raw_read_phys32(struct dmi_sysfs_entry *entry, const struct dmi_system_event_log *sel, char *buf, loff_t pos, size_t count) { … } static ssize_t dmi_sel_raw_read_helper(struct dmi_sysfs_entry *entry, const struct dmi_header *dh, void *_state) { … } static ssize_t dmi_sel_raw_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t pos, size_t count) { … } static struct bin_attribute dmi_sel_raw_attr = …; static int dmi_system_event_log(struct dmi_sysfs_entry *entry) { … } /************************************************* * Generic DMI entry support. *************************************************/ static ssize_t dmi_sysfs_entry_length(struct dmi_sysfs_entry *entry, char *buf) { … } static ssize_t dmi_sysfs_entry_handle(struct dmi_sysfs_entry *entry, char *buf) { … } static ssize_t dmi_sysfs_entry_type(struct dmi_sysfs_entry *entry, char *buf) { … } static ssize_t dmi_sysfs_entry_instance(struct dmi_sysfs_entry *entry, char *buf) { … } static ssize_t dmi_sysfs_entry_position(struct dmi_sysfs_entry *entry, char *buf) { … } static DMI_SYSFS_ATTR(entry, length); static DMI_SYSFS_ATTR(entry, handle); static DMI_SYSFS_ATTR(entry, type); static DMI_SYSFS_ATTR(entry, instance); static DMI_SYSFS_ATTR(entry, position); static struct attribute *dmi_sysfs_entry_attrs[] = …; ATTRIBUTE_GROUPS(…); static ssize_t dmi_entry_raw_read_helper(struct dmi_sysfs_entry *entry, const struct dmi_header *dh, void *_state) { … } static ssize_t dmi_entry_raw_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t pos, size_t count) { … } static const struct bin_attribute dmi_entry_raw_attr = …; static void dmi_sysfs_entry_release(struct kobject *kobj) { … } static const struct kobj_type dmi_sysfs_entry_ktype = …; static struct kset *dmi_kset; /* Global count of all instances seen. Only for setup */ static int __initdata instance_counts[MAX_ENTRY_TYPE + 1]; /* Global positional count of all entries seen. Only for setup */ static int __initdata position_count; static void __init dmi_sysfs_register_handle(const struct dmi_header *dh, void *_ret) { … } static void cleanup_entry_list(void) { … } static int __init dmi_sysfs_init(void) { … } /* clean up everything. */ static void __exit dmi_sysfs_exit(void) { … } module_init(…) …; module_exit(dmi_sysfs_exit); MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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