diff options
Diffstat (limited to 'drivers/acpi/acpi_configfs.c')
| -rw-r--r-- | drivers/acpi/acpi_configfs.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/drivers/acpi/acpi_configfs.c b/drivers/acpi/acpi_configfs.c new file mode 100644 index 000000000..c970792b1 --- /dev/null +++ b/drivers/acpi/acpi_configfs.c @@ -0,0 +1,286 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ACPI configfs support + * + * Copyright (c) 2016 Intel Corporation + */ + +#define pr_fmt(fmt) "ACPI configfs: " fmt + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/configfs.h> +#include <linux/acpi.h> +#include <linux/security.h> + +static struct config_group *acpi_table_group; + +struct acpi_table { + struct config_item cfg; + struct acpi_table_header *header; + u32 index; +}; + +static ssize_t acpi_table_aml_write(struct config_item *cfg, + const void *data, size_t size) +{ + const struct acpi_table_header *header = data; + struct acpi_table *table; + int ret = security_locked_down(LOCKDOWN_ACPI_TABLES); + + if (ret) + return ret; + + table = container_of(cfg, struct acpi_table, cfg); + + if (table->header) { + pr_err("table already loaded\n"); + return -EBUSY; + } + + if (header->length != size) { + pr_err("invalid table length\n"); + return -EINVAL; + } + + if (memcmp(header->signature, ACPI_SIG_SSDT, 4)) { + pr_err("invalid table signature\n"); + return -EINVAL; + } + + table = container_of(cfg, struct acpi_table, cfg); + + table->header = kmemdup(header, header->length, GFP_KERNEL); + if (!table->header) + return -ENOMEM; + + ret = acpi_load_table(table->header, &table->index); + if (ret) { + kfree(table->header); + table->header = NULL; + } + + return ret; +} + +static inline struct acpi_table_header *get_header(struct config_item *cfg) +{ + struct acpi_table *table = container_of(cfg, struct acpi_table, cfg); + + if (!table->header) + pr_err("table not loaded\n"); + + return table->header ?: ERR_PTR(-EINVAL); +} + +static ssize_t acpi_table_aml_read(struct config_item *cfg, + void *data, size_t size) +{ + struct acpi_table_header *h = get_header(cfg); + + if (IS_ERR(h)) + return PTR_ERR(h); + + if (data) + memcpy(data, h, h->length); + + return h->length; +} + +#define MAX_ACPI_TABLE_SIZE (128 * 1024) + +CONFIGFS_BIN_ATTR(acpi_table_, aml, NULL, MAX_ACPI_TABLE_SIZE); + +static struct configfs_bin_attribute *acpi_table_bin_attrs[] = { + &acpi_table_attr_aml, + NULL, +}; + +static ssize_t acpi_table_signature_show(struct config_item *cfg, char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (IS_ERR(h)) + return PTR_ERR(h); + + return sysfs_emit(str, "%.*s\n", ACPI_NAMESEG_SIZE, h->signature); +} + +static ssize_t acpi_table_length_show(struct config_item *cfg, char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (IS_ERR(h)) + return PTR_ERR(h); + + return sysfs_emit(str, "%d\n", h->length); +} + +static ssize_t acpi_table_revision_show(struct config_item *cfg, char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (IS_ERR(h)) + return PTR_ERR(h); + + return sysfs_emit(str, "%d\n", h->revision); +} + +static ssize_t acpi_table_oem_id_show(struct config_item *cfg, char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (IS_ERR(h)) + return PTR_ERR(h); + + return sysfs_emit(str, "%.*s\n", ACPI_OEM_ID_SIZE, h->oem_id); +} + +static ssize_t acpi_table_oem_table_id_show(struct config_item *cfg, char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (IS_ERR(h)) + return PTR_ERR(h); + + return sysfs_emit(str, "%.*s\n", ACPI_OEM_TABLE_ID_SIZE, h->oem_table_id); +} + +static ssize_t acpi_table_oem_revision_show(struct config_item *cfg, char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (IS_ERR(h)) + return PTR_ERR(h); + + return sysfs_emit(str, "%d\n", h->oem_revision); +} + +static ssize_t acpi_table_asl_compiler_id_show(struct config_item *cfg, + char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (IS_ERR(h)) + return PTR_ERR(h); + + return sysfs_emit(str, "%.*s\n", ACPI_NAMESEG_SIZE, h->asl_compiler_id); +} + +static ssize_t acpi_table_asl_compiler_revision_show(struct config_item *cfg, + char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (IS_ERR(h)) + return PTR_ERR(h); + + return sysfs_emit(str, "%d\n", h->asl_compiler_revision); +} + +CONFIGFS_ATTR_RO(acpi_table_, signature); +CONFIGFS_ATTR_RO(acpi_table_, length); +CONFIGFS_ATTR_RO(acpi_table_, revision); +CONFIGFS_ATTR_RO(acpi_table_, oem_id); +CONFIGFS_ATTR_RO(acpi_table_, oem_table_id); +CONFIGFS_ATTR_RO(acpi_table_, oem_revision); +CONFIGFS_ATTR_RO(acpi_table_, asl_compiler_id); +CONFIGFS_ATTR_RO(acpi_table_, asl_compiler_revision); + +static struct configfs_attribute *acpi_table_attrs[] = { + &acpi_table_attr_signature, + &acpi_table_attr_length, + &acpi_table_attr_revision, + &acpi_table_attr_oem_id, + &acpi_table_attr_oem_table_id, + &acpi_table_attr_oem_revision, + &acpi_table_attr_asl_compiler_id, + &acpi_table_attr_asl_compiler_revision, + NULL, +}; + +static const struct config_item_type acpi_table_type = { + .ct_owner = THIS_MODULE, + .ct_bin_attrs = acpi_table_bin_attrs, + .ct_attrs = acpi_table_attrs, +}; + +static struct config_item *acpi_table_make_item(struct config_group *group, + const char *name) +{ + struct acpi_table *table; + + table = kzalloc(sizeof(*table), GFP_KERNEL); + if (!table) + return ERR_PTR(-ENOMEM); + + config_item_init_type_name(&table->cfg, name, &acpi_table_type); + return &table->cfg; +} + +static void acpi_table_drop_item(struct config_group *group, + struct config_item *cfg) +{ + struct acpi_table *table = container_of(cfg, struct acpi_table, cfg); + + pr_debug("Host-directed Dynamic ACPI Table Unload\n"); + acpi_unload_table(table->index); + config_item_put(cfg); +} + +static struct configfs_group_operations acpi_table_group_ops = { + .make_item = acpi_table_make_item, + .drop_item = acpi_table_drop_item, +}; + +static const struct config_item_type acpi_tables_type = { + .ct_owner = THIS_MODULE, + .ct_group_ops = &acpi_table_group_ops, +}; + +static const struct config_item_type acpi_root_group_type = { + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem acpi_configfs = { + .su_group = { + .cg_item = { + .ci_namebuf = "acpi", + .ci_type = &acpi_root_group_type, + }, + }, + .su_mutex = __MUTEX_INITIALIZER(acpi_configfs.su_mutex), +}; + +static int __init acpi_configfs_init(void) +{ + int ret; + struct config_group *root = &acpi_configfs.su_group; + + config_group_init(root); + + ret = configfs_register_subsystem(&acpi_configfs); + if (ret) + return ret; + + acpi_table_group = configfs_register_default_group(root, "table", + &acpi_tables_type); + if (IS_ERR(acpi_table_group)) { + configfs_unregister_subsystem(&acpi_configfs); + return PTR_ERR(acpi_table_group); + } + + return 0; +} +module_init(acpi_configfs_init); + +static void __exit acpi_configfs_exit(void) +{ + configfs_unregister_default_group(acpi_table_group); + configfs_unregister_subsystem(&acpi_configfs); +} +module_exit(acpi_configfs_exit); + +MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>"); +MODULE_DESCRIPTION("ACPI configfs support"); +MODULE_LICENSE("GPL v2"); |