From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tim Hockin <thockin-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH v1 2/5] firmware: Basic dmi-sysfs support
Date: Thu, 17 Feb 2011 13:42:45 -0800
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To: Mike Waychison <mikew-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Cc: Greg KH <greg-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>, Olof Johansson <olofj-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>, Andi Kleen <andi-Vw/NltI1exuRpAAqCnN02g@public.gmane.org>, Alan Cox <alan-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org>, Robert Lippert <rlippert-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, Jon Mayer <jonmayer-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, Duncan Laurie <dlaurie-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, Aaron Durbin <adurbin-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, David Hendrix <dhendrix-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
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On Thu, Feb 17, 2011 at 1:28 PM, Mike Waychison <mikew-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> wrot=
e:
> Introduce a new module "dmi-sysfs" that exports the broken out entrie=
s
> of the DMI table through sysfs.
>
> Entries are enumerated via dmi_walk() on module load, and are populat=
ed
> as kobjects rooted at /sys/firmware/dmi/entries.
>
> Entries are named "<type>-<instance>", where:
> =A0 <type> =A0 =A0 =A0 : is the type of the entry, and
> =A0 <instance> =A0 : is the ordinal count within the DMI table of tha=
t
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0entry type. =A0This instance is us=
ed in lieu the DMI
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0entry's handle as no assurances ar=
e made by the kernel
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0that handles are unique.
>
> All entries export the following attributes:
> =A0 length =A0 =A0 =A0 : The length of the formatted portion of the e=
ntry
> =A0 handle =A0 =A0 =A0 : The handle given to this entry by the firmwa=
re
> =A0 raw =A0 =A0 =A0 =A0 =A0: The raw bytes of the entire entry, inclu=
ding the
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0formatted portion, the unformatted=
 (strings) portion,
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0and the two terminating nul charac=
ters.

Is it worth dropping another file here for type (and maybe one for
ordinal)?  I know they are in the dir name, but something nags at me
that they would be useful here.

>
> Entries in dmi-sysfs are kobject backed members called "struct
> dmi_sysfs_entry" and belong to dmi_kset. =A0They are threaded through
> entry_list (protected by entry_list_lock) so that we can find them at
> cleanup time.
>
> Signed-off-by: Mike Waychison <mikew-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
> ---
> =A0drivers/firmware/Kconfig =A0 =A0 | =A0 11 +
> =A0drivers/firmware/Makefile =A0 =A0| =A0 =A01
> =A0drivers/firmware/dmi-sysfs.c | =A0362 ++++++++++++++++++++++++++++=
++++++++++++++
> =A03 files changed, 374 insertions(+), 0 deletions(-)
> =A0create mode 100644 drivers/firmware/dmi-sysfs.c
>
> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
> index e710424..959175d 100644
> --- a/drivers/firmware/Kconfig
> +++ b/drivers/firmware/Kconfig
> @@ -113,6 +113,17 @@ config DMIID
> =A0 =A0 =A0 =A0 =A0information from userspace through /sys/class/dmi/=
id/ or if you want
> =A0 =A0 =A0 =A0 =A0DMI-based module auto-loading.
>
> +config DMI_SYSFS
> + =A0 =A0 =A0 tristate "DMI table support in sysfs"
> + =A0 =A0 =A0 depends on SYSFS && DMI
> + =A0 =A0 =A0 default X86
> + =A0 =A0 =A0 help
> + =A0 =A0 =A0 =A0 Say Y or M here to enable the exporting of the raw =
DMI table
> + =A0 =A0 =A0 =A0 data via sysfs. =A0This is useful for consuming the=
 data without
> + =A0 =A0 =A0 =A0 requiring any access to /dev/mem at all. =A0Tables =
are found
> + =A0 =A0 =A0 =A0 under /sys/firmware/dmi when this option is enabled=
 and
> + =A0 =A0 =A0 =A0 loaded.
> +
> =A0config ISCSI_IBFT_FIND
> =A0 =A0 =A0 =A0bool "iSCSI Boot Firmware Table Attributes"
> =A0 =A0 =A0 =A0depends on X86
> diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
> index 1c3c173..20c17fc 100644
> --- a/drivers/firmware/Makefile
> +++ b/drivers/firmware/Makefile
> @@ -2,6 +2,7 @@
> =A0# Makefile for the linux kernel.
> =A0#
> =A0obj-$(CONFIG_DMI) =A0 =A0 =A0 =A0 =A0 =A0 =A0+=3D dmi_scan.o
> +obj-$(CONFIG_DMI_SYSFS) =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0+=3D dmi-sysf=
s.o
> =A0obj-$(CONFIG_EDD) =A0 =A0 =A0 =A0 =A0 =A0 =A0+=3D edd.o
> =A0obj-$(CONFIG_EFI_VARS) =A0 =A0 =A0 =A0 +=3D efivars.o
> =A0obj-$(CONFIG_EFI_PCDP) =A0 =A0 =A0 =A0 +=3D pcdp.o
> diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysf=
s.c
> new file mode 100644
> index 0000000..adcd604
> --- /dev/null
> +++ b/drivers/firmware/dmi-sysfs.c
> @@ -0,0 +1,362 @@
> +/*
> + * dmi-sysfs.c
> + *
> + * This module exports the DMI tables read-only to userspace through=
 the
> + * sysfs file system.
> + *
> + * Data is currently found below
> + * =A0 =A0/sys/firmware/dmi/...
> + *
> + * DMI attributes are presented in attribute files with names
> + * formatted using %d-%d, so that the first integer indicates the
> + * structure type (0-255), and the second field is the instance of t=
hat
> + * entry.
> + *
> + * Copyright 2010 Google, Inc.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/types.h>
> +#include <linux/kobject.h>
> +#include <linux/dmi.h>
> +#include <linux/capability.h>
> +#include <linux/slab.h>
> +#include <linux/list.h>
> +#include <linux/io.h>
> +
> +#define MAX_ENTRY_TYPE 255 /* Most of these aren't used, but we cons=
ider
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 the top ent=
ry type is only 8 bits */
> +
> +struct dmi_sysfs_entry {
> + =A0 =A0 =A0 struct dmi_header dh;
> + =A0 =A0 =A0 struct kobject kobj;
> + =A0 =A0 =A0 int instance;
> + =A0 =A0 =A0 struct list_head list;
> +};
> +
> +/*
> + * Global list of dmi_sysfs_entry. =A0Even though this should only b=
e
> + * manipulated at setup and teardown, the lazy nature of the kobject
> + * system means we get lazy removes.
> + */
> +static LIST_HEAD(entry_list);
> +static DEFINE_SPINLOCK(entry_list_lock);
> +
> +/* dmi_sysfs_attribute - Top level attribute. used by all entries. *=
/
> +struct dmi_sysfs_attribute {
> + =A0 =A0 =A0 struct attribute attr;
> + =A0 =A0 =A0 ssize_t (*show)(struct dmi_sysfs_entry *entry, char *bu=
f);
> +};
> +
> +#define DMI_SYSFS_ATTR(_entry, _name) \
> +struct dmi_sysfs_attribute dmi_sysfs_attr_##_entry##_##_name =3D { \
> + =A0 =A0 =A0 .attr =3D {.name =3D __stringify(_name), .mode =3D 0400=
}, \
> + =A0 =A0 =A0 .show =3D dmi_sysfs_##_entry##_##_name, \
> +}
> +
> +/*
> + * dmi_sysfs_mapped_attribute - Attribute where we require the entry=
 be
> + * mapped in. =A0Use in conjunction with dmi_sysfs_specialize_attr_o=
ps.
> + */
> +struct dmi_sysfs_mapped_attribute {
> + =A0 =A0 =A0 struct attribute attr;
> + =A0 =A0 =A0 ssize_t (*show)(struct dmi_sysfs_entry *entry,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 const struct dmi_header=
 *dh,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 char *buf);
> +};
> +
> +#define DMI_SYSFS_MAPPED_ATTR(_entry, _name) \
> +struct dmi_sysfs_mapped_attribute dmi_sysfs_attr_##_entry##_##_name =
=3D { \
> + =A0 =A0 =A0 .attr =3D {.name =3D __stringify(_name), .mode =3D 0400=
}, \
> + =A0 =A0 =A0 .show =3D dmi_sysfs_##_entry##_##_name, \
> +}
> +
> +/*************************************************
> + * Generic DMI entry support.
> + *************************************************/
> +
> +static struct dmi_sysfs_entry *to_entry(struct kobject *kobj)
> +{
> + =A0 =A0 =A0 return container_of(kobj, struct dmi_sysfs_entry, kobj)=
;
> +}
> +
> +static struct dmi_sysfs_attribute *to_attr(struct attribute *attr)
> +{
> + =A0 =A0 =A0 return container_of(attr, struct dmi_sysfs_attribute, a=
ttr);
> +}
> +
> +static ssize_t dmi_sysfs_attr_show(struct kobject *kobj,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=
struct attribute *_attr, char *buf)
> +{
> + =A0 =A0 =A0 struct dmi_sysfs_entry *entry =3D to_entry(kobj);
> + =A0 =A0 =A0 struct dmi_sysfs_attribute *attr =3D to_attr(_attr);
> +
> + =A0 =A0 =A0 /* DMI stuff is only ever admin visible */
> + =A0 =A0 =A0 if (!capable(CAP_SYS_ADMIN))
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 return -EACCES;
> +
> + =A0 =A0 =A0 return attr->show(entry, buf);
> +}
> +
> +static const struct sysfs_ops dmi_sysfs_attr_ops =3D {
> + =A0 =A0 =A0 .show =3D dmi_sysfs_attr_show,
> +};
> +
> +typedef ssize_t (*dmi_callback)(struct dmi_sysfs_entry *,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 const s=
truct dmi_header *dh, void *);
> +
> +struct find_dmi_data {
> + =A0 =A0 =A0 struct dmi_sysfs_entry =A0*entry;
> + =A0 =A0 =A0 dmi_callback =A0 =A0 =A0 =A0 =A0 =A0callback;
> + =A0 =A0 =A0 void =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0*private;
> + =A0 =A0 =A0 int =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 instance_co=
untdown;
> + =A0 =A0 =A0 ssize_t =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ret;
> +};
> +
> +static void find_dmi_entry_helper(const struct dmi_header *dh,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 voi=
d *_data)
> +{
> + =A0 =A0 =A0 struct find_dmi_data *data =3D _data;
> + =A0 =A0 =A0 struct dmi_sysfs_entry *entry =3D data->entry;
> +
> + =A0 =A0 =A0 /* Is this the entry we want? */
> + =A0 =A0 =A0 if (dh->type !=3D entry->dh.type)
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 return;
> +
> + =A0 =A0 =A0 if (data->instance_countdown !=3D 0) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 /* try the next instance? */
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 data->instance_countdown--;
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 return;
> + =A0 =A0 =A0 }
> +
> + =A0 =A0 =A0 /* Found the entry */
> + =A0 =A0 =A0 data->ret =3D data->callback(entry, dh, data->private);
> +}
> +
> +/* State for passing the read parameters through dmi_find_entry() */
> +struct dmi_read_state {
> + =A0 =A0 =A0 char *buf;
> + =A0 =A0 =A0 loff_t pos;
> + =A0 =A0 =A0 size_t count;
> +};
> +
> +static ssize_t find_dmi_entry(struct dmi_sysfs_entry *entry,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 dmi_callbac=
k callback, void *private)
> +{
> + =A0 =A0 =A0 struct find_dmi_data data =3D {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 .entry =3D entry,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 .callback =3D callback,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 .private =3D private,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 .instance_countdown =3D entry->instance=
,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 .ret =3D -EIO, =A0/* To signal the entr=
y disappeared */
> + =A0 =A0 =A0 };
> + =A0 =A0 =A0 int ret;
> +
> + =A0 =A0 =A0 ret =3D dmi_walk(find_dmi_entry_helper, &data);
> + =A0 =A0 =A0 /* This shouldn't happen, but just in case. */
> + =A0 =A0 =A0 if (ret)
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 return -EINVAL;
> + =A0 =A0 =A0 return data.ret;
> +}
> +
> +/*
> + * Calculate and return the byte length of the dmi entry identified =
by
> + * dh. =A0This includes both the formatted portion as well as the
> + * unformatted string space, including the two trailing nul characte=
rs.
> + */
> +static size_t dmi_entry_length(const struct dmi_header *dh)
> +{
> + =A0 =A0 =A0 const char *p =3D (const char *)dh;
> +
> + =A0 =A0 =A0 p +=3D dh->length;
> +
> + =A0 =A0 =A0 while (p[0] || p[1])
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 p++;
> +
> + =A0 =A0 =A0 return 2 + p - (const char *)dh;
> +}
> +
> +/*************************************************
> + * Generic DMI entry support.
> + *************************************************/
> +
> +static ssize_t dmi_sysfs_entry_length(struct dmi_sysfs_entry *entry,=
 char *buf)
> +{
> + =A0 =A0 =A0 return sprintf(buf, "%d\n", entry->dh.length);
> +}
> +
> +static ssize_t dmi_sysfs_entry_handle(struct dmi_sysfs_entry *entry,=
 char *buf)
> +{
> + =A0 =A0 =A0 return sprintf(buf, "%d\n", entry->dh.handle);
> +}
> +
> +static DMI_SYSFS_ATTR(entry, length);
> +static DMI_SYSFS_ATTR(entry, handle);
> +
> +static struct attribute *dmi_sysfs_entry_attrs[] =3D {
> + =A0 =A0 =A0 &dmi_sysfs_attr_entry_length.attr,
> + =A0 =A0 =A0 &dmi_sysfs_attr_entry_handle.attr,
> + =A0 =A0 =A0 NULL,
> +};
> +
> +static ssize_t dmi_entry_raw_read_helper(struct dmi_sysfs_entry *ent=
ry,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=
 =A0 =A0 =A0const struct dmi_header *dh,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=
 =A0 =A0 =A0void *_state)
> +{
> + =A0 =A0 =A0 struct dmi_read_state *state =3D _state;
> + =A0 =A0 =A0 size_t entry_length;
> +
> + =A0 =A0 =A0 entry_length =3D dmi_entry_length(dh);
> +
> + =A0 =A0 =A0 return memory_read_from_buffer(state->buf, state->count=
,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=
 =A0 =A0&state->pos, dh, entry_length);
> +}
> +
> +static ssize_t dmi_entry_raw_read(struct file *filp,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 str=
uct kobject *kobj,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 str=
uct bin_attribute *bin_attr,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 cha=
r *buf, loff_t pos, size_t count)
> +{
> + =A0 =A0 =A0 struct dmi_sysfs_entry *entry =3D to_entry(kobj);
> + =A0 =A0 =A0 struct dmi_read_state state =3D {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 .buf =3D buf,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 .pos =3D pos,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 .count =3D count,
> + =A0 =A0 =A0 };
> +
> + =A0 =A0 =A0 return find_dmi_entry(entry, dmi_entry_raw_read_helper,=
 &state);
> +}
> +
> +static const struct bin_attribute dmi_entry_raw_attr =3D {
> + =A0 =A0 =A0 .attr =3D {.name =3D "raw", .mode =3D 0400},
> + =A0 =A0 =A0 .read =3D dmi_entry_raw_read,
> +};
> +
> +static void dmi_sysfs_entry_release(struct kobject *kobj)
> +{
> + =A0 =A0 =A0 struct dmi_sysfs_entry *entry =3D to_entry(kobj);
> + =A0 =A0 =A0 sysfs_remove_bin_file(&entry->kobj, &dmi_entry_raw_attr=
);
> + =A0 =A0 =A0 spin_lock(&entry_list_lock);
> + =A0 =A0 =A0 list_del(&entry->list);
> + =A0 =A0 =A0 spin_unlock(&entry_list_lock);
> + =A0 =A0 =A0 kfree(entry);
> +}
> +
> +static struct kobj_type dmi_sysfs_entry_ktype =3D {
> + =A0 =A0 =A0 .release =3D dmi_sysfs_entry_release,
> + =A0 =A0 =A0 .sysfs_ops =3D &dmi_sysfs_attr_ops,
> + =A0 =A0 =A0 .default_attrs =3D dmi_sysfs_entry_attrs,
> +};
> +
> +static struct kobject *dmi_kobj;
> +static struct kset *dmi_kset;
> +
> +/* Global count of all instances seen. =A0Only for setup */
> +static int __initdata instance_counts[MAX_ENTRY_TYPE + 1];
> +
> +static void __init dmi_sysfs_register_handle(const struct dmi_header=
 *dh,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=
 =A0 =A0 =A0 =A0 =A0void *_ret)
> +{
> + =A0 =A0 =A0 struct dmi_sysfs_entry *entry;
> + =A0 =A0 =A0 int *ret =3D _ret;
> +
> + =A0 =A0 =A0 /* If a previous entry saw an error, short circuit */
> + =A0 =A0 =A0 if (*ret)
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 return;
> +
> + =A0 =A0 =A0 /* Allocate and register a new entry into the entries s=
et */
> + =A0 =A0 =A0 entry =3D kzalloc(sizeof(*entry), GFP_KERNEL);
> + =A0 =A0 =A0 if (!entry) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 *ret =3D -ENOMEM;
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 return;
> + =A0 =A0 =A0 }
> +
> + =A0 =A0 =A0 /* Set the key */
> + =A0 =A0 =A0 entry->dh =3D *dh;
> + =A0 =A0 =A0 entry->instance =3D instance_counts[dh->type]++;
> +
> + =A0 =A0 =A0 entry->kobj.kset =3D dmi_kset;
> + =A0 =A0 =A0 *ret =3D kobject_init_and_add(&entry->kobj, &dmi_sysfs_=
entry_ktype, NULL,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=
 "%d-%d", dh->type, entry->instance);
> +
> + =A0 =A0 =A0 if (*ret) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 kfree(entry);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 return;
> + =A0 =A0 =A0 }
> +
> + =A0 =A0 =A0 /* Thread on the global list for cleanup */
> + =A0 =A0 =A0 spin_lock(&entry_list_lock);
> + =A0 =A0 =A0 list_add_tail(&entry->list, &entry_list);
> + =A0 =A0 =A0 spin_unlock(&entry_list_lock);
> +
> + =A0 =A0 =A0 /* Create the raw binary file to access the entry */
> + =A0 =A0 =A0 *ret =3D sysfs_create_bin_file(&entry->kobj, &dmi_entry=
_raw_attr);
> + =A0 =A0 =A0 if (*ret)
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 goto out_err;
> +
> + =A0 =A0 =A0 return;
> +out_err:
> + =A0 =A0 =A0 kobject_put(&entry->kobj);
> + =A0 =A0 =A0 return;
> +}
> +
> +static void cleanup_entry_list(void)
> +{
> + =A0 =A0 =A0 struct dmi_sysfs_entry *entry, *next;
> +
> + =A0 =A0 =A0 /* No locks, we are on our way out */
> + =A0 =A0 =A0 list_for_each_entry_safe(entry, next, &entry_list, list=
) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 kobject_put(&entry->kobj);
> + =A0 =A0 =A0 }
> +}
> +
> +static int __init dmi_sysfs_init(void)
> +{
> + =A0 =A0 =A0 int error =3D -ENOMEM;
> + =A0 =A0 =A0 int val;
> +
> + =A0 =A0 =A0 /* Set up our directory */
> + =A0 =A0 =A0 dmi_kobj =3D kobject_create_and_add("dmi", firmware_kob=
j);
> + =A0 =A0 =A0 if (!dmi_kobj)
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 goto err;
> +
> + =A0 =A0 =A0 dmi_kset =3D kset_create_and_add("entries", NULL, dmi_k=
obj);
> + =A0 =A0 =A0 if (!dmi_kset)
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 goto err;
> +
> + =A0 =A0 =A0 val =3D 0;
> + =A0 =A0 =A0 error =3D dmi_walk(dmi_sysfs_register_handle, &val);
> + =A0 =A0 =A0 if (error)
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 goto err;
> + =A0 =A0 =A0 if (val) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 error =3D val;
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 goto err;
> + =A0 =A0 =A0 }
> +
> + =A0 =A0 =A0 pr_info("dmi-sysfs: loaded.\n");
> +
> + =A0 =A0 =A0 return 0;
> +err:
> + =A0 =A0 =A0 cleanup_entry_list();
> + =A0 =A0 =A0 kset_unregister(dmi_kset);
> + =A0 =A0 =A0 kobject_put(dmi_kobj);
> + =A0 =A0 =A0 return error;
> +}
> +
> +/* clean up everything. */
> +static void __exit dmi_sysfs_exit(void)
> +{
> + =A0 =A0 =A0 pr_info("dmi-sysfs: unloading.\n");
> + =A0 =A0 =A0 cleanup_entry_list();
> + =A0 =A0 =A0 kset_unregister(dmi_kset);
> + =A0 =A0 =A0 kobject_put(dmi_kobj);
> +}
> +
> +module_init(dmi_sysfs_init);
> +module_exit(dmi_sysfs_exit);
> +
> +MODULE_AUTHOR("Google, Inc.");
> +MODULE_DESCRIPTION("DMI sysfs support");
> +MODULE_LICENSE("GPL");
>
>