diff options
| -rw-r--r-- | Documentation/ABI/testing/configfs-acpi | 29 | ||||
| -rw-r--r-- | Documentation/acpi/ssdt-overlays.txt | 14 | ||||
| -rw-r--r-- | drivers/acpi/configfs.c | 216 |
3 files changed, 258 insertions, 1 deletions
diff --git a/Documentation/ABI/testing/configfs-acpi b/Documentation/ABI/testing/configfs-acpi index 17b19dc2822d..4ab4e99aa863 100644 --- a/Documentation/ABI/testing/configfs-acpi +++ b/Documentation/ABI/testing/configfs-acpi @@ -5,3 +5,32 @@ Contact: linux-acpi@vger.kernel.org Description: This represents the ACPI subsystem entry point directory. It contains sub-groups corresponding to ACPI configurable options. + +What: /config/acpi/table +Date: July 2016 +KernelVersion: 4.8 +Description: + + This group contains the configuration for user defined ACPI + tables. The attributes of a user define table are: + + aml - a binary attribute that the user can use to + fill in the ACPI aml definitions. Once the aml + data is written to this file and the file is + closed the table will be loaded and ACPI devices + will be enumerated. To check if the operation is + successful the user must check the error code + for close(). If the operation is successful, + subsequent writes to this attribute will fail. + + The rest of the attributes are read-only and are valid only + after the table has been loaded by filling the aml entry: + + signature - ASCII table signature + length - length of table in bytes, including the header + revision - ACPI Specification minor version number + oem_id - ASCII OEM identification + oem_table_id - ASCII OEM table identification + oem_revision - OEM revision number + asl_compiler_id - ASCII ASL compiler vendor ID + asl_compiler_revision - ASL compiler version diff --git a/Documentation/acpi/ssdt-overlays.txt b/Documentation/acpi/ssdt-overlays.txt index c4b57badd0b7..5ae13f161ea2 100644 --- a/Documentation/acpi/ssdt-overlays.txt +++ b/Documentation/acpi/ssdt-overlays.txt @@ -156,3 +156,17 @@ tmp=$(mktemp) /bin/echo -ne "\007\000\000\000" | cat - $filename > $tmp dd if=$tmp of="$EFIVARFS/$name-$guid" bs=$(stat -c %s $tmp) rm $tmp + +== Loading ACPI SSDTs from configfs == + +This option allows loading of user defined SSDTs from userspace via the configfs +interface. The CONFIG_ACPI_CONFIGFS option must be select and configfs must be +mounted. In the following examples, we assume that configfs has been mounted in +/config. + +New tables can be loading by creating new directories in /config/acpi/table/ and +writing the SSDT aml code in the aml attribute: + +cd /config/acpi/table +mkdir my_ssdt +cat ~/ssdt.aml > my_ssdt/aml diff --git a/drivers/acpi/configfs.c b/drivers/acpi/configfs.c index 44b463f6fca5..146a77fb762d 100644 --- a/drivers/acpi/configfs.c +++ b/drivers/acpi/configfs.c @@ -8,11 +8,222 @@ * the Free Software Foundation. */ +#define pr_fmt(fmt) "ACPI configfs: " fmt + #include <linux/init.h> #include <linux/module.h> #include <linux/configfs.h> #include <linux/acpi.h> +static struct config_group *acpi_table_group; + +struct acpi_table { + struct config_item cfg; + struct acpi_table_header *header; +}; + +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; + + 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); + 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; +} + +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 (!h) + return -EINVAL; + + 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); + +struct configfs_bin_attribute *acpi_table_bin_attrs[] = { + &acpi_table_attr_aml, + NULL, +}; + +ssize_t acpi_table_signature_show(struct config_item *cfg, char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (!h) + return -EINVAL; + + return sprintf(str, "%.*s\n", ACPI_NAME_SIZE, h->signature); +} + +ssize_t acpi_table_length_show(struct config_item *cfg, char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (!h) + return -EINVAL; + + return sprintf(str, "%d\n", h->length); +} + +ssize_t acpi_table_revision_show(struct config_item *cfg, char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (!h) + return -EINVAL; + + return sprintf(str, "%d\n", h->revision); +} + +ssize_t acpi_table_oem_id_show(struct config_item *cfg, char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (!h) + return -EINVAL; + + return sprintf(str, "%.*s\n", ACPI_OEM_ID_SIZE, h->oem_id); +} + +ssize_t acpi_table_oem_table_id_show(struct config_item *cfg, char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (!h) + return -EINVAL; + + return sprintf(str, "%.*s\n", ACPI_OEM_TABLE_ID_SIZE, h->oem_table_id); +} + +ssize_t acpi_table_oem_revision_show(struct config_item *cfg, char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (!h) + return -EINVAL; + + return sprintf(str, "%d\n", h->oem_revision); +} + +ssize_t acpi_table_asl_compiler_id_show(struct config_item *cfg, char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (!h) + return -EINVAL; + + return sprintf(str, "%.*s\n", ACPI_NAME_SIZE, h->asl_compiler_id); +} + +ssize_t acpi_table_asl_compiler_revision_show(struct config_item *cfg, + char *str) +{ + struct acpi_table_header *h = get_header(cfg); + + if (!h) + return -EINVAL; + + return sprintf(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); + +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 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; +} + +struct configfs_group_operations acpi_table_group_ops = { + .make_item = acpi_table_make_item, +}; + +static struct config_item_type acpi_tables_type = { + .ct_owner = THIS_MODULE, + .ct_group_ops = &acpi_table_group_ops, +}; + static struct config_item_type acpi_root_group_type = { .ct_owner = THIS_MODULE, }; @@ -38,12 +249,15 @@ static int __init acpi_configfs_init(void) if (ret) return ret; - return 0; + acpi_table_group = configfs_register_default_group(root, "table", + &acpi_tables_type); + return PTR_ERR_OR_ZERO(acpi_table_group); } 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); |