The optional type 15 entry of the DMI table describes a non-volatile
storage-backed system event log.
In preparation for the next commit which exposes the raw bits of the
event log to userland, create a new sub-directory within the dmi entry
called "system_event_log" and expose attribute files that describe the
event log itself.
Currently, only a single child object is permitted within a
dmi_sysfs_entry. We simply point at this child from the dmi_sysfs_entry
if it exists.
Signed-off-by: Mike Waychison <mikew@xxxxxxxxxx>
---
drivers/firmware/dmi-sysfs.c | 159 ++++++++++++++++++++++++++++++++++++++++++
1 files changed, 159 insertions(+), 0 deletions(-)
diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysfs.c
index adcd604..3f49042 100644
--- a/drivers/firmware/dmi-sysfs.c
+++ b/drivers/firmware/dmi-sysfs.c
@@ -34,6 +34,7 @@ struct dmi_sysfs_entry {
struct kobject kobj;
int instance;
struct list_head list;
+ struct kobject *child;
};
/*
@@ -76,6 +77,10 @@ struct dmi_sysfs_mapped_attribute dmi_sysfs_attr_##_entry##_##_name = { \
/*************************************************
* Generic DMI entry support.
*************************************************/
+static void dmi_entry_free(struct kobject *kobj)
+{
+ kfree(kobj);
+}
static struct dmi_sysfs_entry *to_entry(struct kobject *kobj)
{
@@ -179,6 +184,146 @@ static size_t dmi_entry_length(const struct dmi_header *dh)
}
/*************************************************
+ * Support bits for specialized DMI entry support
+ *************************************************/
+struct dmi_entry_attr_show_data {
+ struct attribute *attr;
+ char *buf;
+};
+
+static ssize_t dmi_entry_attr_show_helper(struct dmi_sysfs_entry *entry,
+ const struct dmi_header *dh,
+ void *_data)
+{
+ struct dmi_entry_attr_show_data *data = _data;
+ struct dmi_sysfs_mapped_attribute *attr;
+
+ attr = container_of(data->attr,
+ struct dmi_sysfs_mapped_attribute, attr);
+ return attr->show(entry, dh, data->buf);
+}
+
+static ssize_t dmi_entry_attr_show(struct kobject *kobj,
+ struct attribute *attr,
+ char *buf)
+{
+ struct dmi_entry_attr_show_data data = {
+ .attr = attr,
+ .buf = buf,
+ };
+ /* Find the entry according to our parent and call the
+ * normalized show method hanging off of the attribute */
+ return find_dmi_entry(to_entry(kobj->parent),
+ dmi_entry_attr_show_helper, &data);
+}
+
+static const struct sysfs_ops dmi_sysfs_specialize_attr_ops = {
+ .show = dmi_entry_attr_show,
+};
+
+/*************************************************
+ * Specialized DMI entry support.
+ *************************************************/
+
+/*** Type 15 - System Event Table ***/
+
+#define DMI_SEL_ACCESS_METHOD_IO8 0x00
+#define DMI_SEL_ACCESS_METHOD_IO2x8 0x01
+#define DMI_SEL_ACCESS_METHOD_IO16 0x02
+#define DMI_SEL_ACCESS_METHOD_PHYS32 0x03
+#define DMI_SEL_ACCESS_METHOD_GPNV 0x04
+
+struct dmi_system_event_log {
+ struct dmi_header header;
+ u16 area_length;
+ u16 header_start_offset;
+ u16 data_start_offset;
+ u8 access_method;
+ u8 status;
+ u32 change_token;
+ union {
+ struct {
+ u16 index_addr;
+ u16 data_addr;
+ } io;
+ u32 phys_addr32;
+ u16 gpnv_handle;
+ u32 access_method_address;
+ };
+ u8 header_format;
+ u8 type_descriptors_supported_count;
+ u8 per_log_type_descriptor_length;
+ u8 supported_log_type_descriptos[0];
+} __packed;
+
+static const struct dmi_system_event_log *to_sel(const struct dmi_header *dh)
+{
+ return (const struct dmi_system_event_log *)dh;
+}
+
+#define DMI_SYSFS_SEL_FIELD(_field) \
+static ssize_t dmi_sysfs_sel_##_field(struct dmi_sysfs_entry *entry, \
+ const struct dmi_header *dh, \
+ char *buf) \
+{ \
+ const struct dmi_system_event_log *sel = to_sel(dh); \
+ if (sizeof(*sel) > dmi_entry_length(dh)) \
+ return -EIO; \
+ return sprintf(buf, "%u\n", sel->_field); \
+} \
+static DMI_SYSFS_MAPPED_ATTR(sel, _field)
+
+DMI_SYSFS_SEL_FIELD(area_length);
+DMI_SYSFS_SEL_FIELD(header_start_offset);
+DMI_SYSFS_SEL_FIELD(data_start_offset);
+DMI_SYSFS_SEL_FIELD(access_method);
+DMI_SYSFS_SEL_FIELD(status);
+DMI_SYSFS_SEL_FIELD(change_token);
+DMI_SYSFS_SEL_FIELD(access_method_address);
+DMI_SYSFS_SEL_FIELD(header_format);
+DMI_SYSFS_SEL_FIELD(type_descriptors_supported_count);
+DMI_SYSFS_SEL_FIELD(per_log_type_descriptor_length);
+
+static struct attribute *dmi_sysfs_sel_attrs[] = {
+ &dmi_sysfs_attr_sel_area_length.attr,
+ &dmi_sysfs_attr_sel_header_start_offset.attr,
+ &dmi_sysfs_attr_sel_data_start_offset.attr,
+ &dmi_sysfs_attr_sel_access_method.attr,
+ &dmi_sysfs_attr_sel_status.attr,
+ &dmi_sysfs_attr_sel_change_token.attr,
+ &dmi_sysfs_attr_sel_access_method_address.attr,
+ &dmi_sysfs_attr_sel_header_format.attr,
+ &dmi_sysfs_attr_sel_type_descriptors_supported_count.attr,
+ &dmi_sysfs_attr_sel_per_log_type_descriptor_length.attr,
+ NULL,
+};
+
+
+static struct kobj_type dmi_system_event_log_ktype = {
+ .release = dmi_entry_free,
+ .sysfs_ops = &dmi_sysfs_specialize_attr_ops,
+ .default_attrs = dmi_sysfs_sel_attrs,
+};
+
+static int dmi_system_event_log(struct dmi_sysfs_entry *entry)
+{
+ int ret;
+
+ entry->child = kzalloc(sizeof(*entry->child), GFP_KERNEL);
+ if (!entry->child)
+ return -ENOMEM;
+ ret = kobject_init_and_add(entry->child,
+ &dmi_system_event_log_ktype,
+ &entry->kobj,
+ "system_event_log");
+ if (ret)
+ goto out_free;
+out_free:
+ kfree(entry->child);
+ return ret;
+}
+
+/*************************************************
* Generic DMI entry support.
*************************************************/
@@ -291,6 +436,18 @@ static void __init dmi_sysfs_register_handle(const struct dmi_header *dh,
list_add_tail(&entry->list, &entry_list);
spin_unlock(&entry_list_lock);
+ /* Handle specializations by type */
+ switch (dh->type) {
+ case DMI_ENTRY_SYSTEM_EVENT_LOG:
+ *ret = dmi_system_event_log(entry);
+ break;
+ default:
+ /* No specialization */
+ break;
+ }
+ if (*ret)
+ goto out_err;
+
/* Create the raw binary file to access the entry */
*ret = sysfs_create_bin_file(&entry->kobj, &dmi_entry_raw_attr);
if (*ret)
@@ -298,6 +455,7 @@ static void __init dmi_sysfs_register_handle(const struct dmi_header *dh,
return;
out_err:
+ kobject_put(entry->child);
kobject_put(&entry->kobj);
return;
}
@@ -308,6 +466,7 @@ static void cleanup_entry_list(void)
/* No locks, we are on our way out */
list_for_each_entry_safe(entry, next, &entry_list, list) {
+ kobject_put(entry->child);
kobject_put(&entry->kobj);
}
}
--
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