Commit 925a1da7 authored by Mike Waychison's avatar Mike Waychison Committed by Greg Kroah-Hartman
Browse files

firmware: Break out system_event_log in dmi-sysfs 



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: default avatarMike Waychison <mikew@google.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 948af1f0

drivers/firmware/dmi-sysfs.c

+159 −0
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ struct dmi_sysfs_entry { 
	int instance;

	int position;

	struct list_head list;

	struct kobject *child;

};



/*
@@ -77,6 +78,10 @@ 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)

{
@@ -185,6 +190,146 @@ static size_t dmi_entry_length(const struct dmi_header *dh) 
	return 2 + p - (const char *)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.

 *************************************************/
@@ -325,6 +470,18 @@ 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)
@@ -332,6 +489,7 @@ static void __init dmi_sysfs_register_handle(const struct dmi_header *dh, 


	return;

out_err:

	kobject_put(entry->child);

	kobject_put(&entry->kobj);

	return;

}
@@ -342,6 +500,7 @@ 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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