diff --git a/Documentation/ABI/testing/configfs-acpi b/Documentation/ABI/testing/configfs-acpi
index 17b19dc2822d4e48fe36a380482ce6495bcb0009..4ab4e99aa863e5054ff28abc5e5a75613d96f4de 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 c4b57badd0b77880431c6eda08bacfab2b03f3b5..5ae13f161ea2b98d924b5e688a8b75274778f0dd 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 44b463f6fca544735bc46256223c7b177dae3ea4..146a77fb762d5b3083d68fc1774ba01ae5f127a1 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);