RE: [BK PATCH] add SMBIOS tables to sysfs

RE: [BK PATCH] add SMBIOS tables to sysfs

[Michael_E_Brown]

> -----Original Message-----
> From: Greg KH [mailto:greg@kroah.com] 
> 
> Ok, here are 2 patches.  The first small one is on top of your latest
> version.  It gets rid of the extra subdirectory, and removes the
> unneeded kobject from your static structure (NEVER USE A KOBJECT IN A
> STATIC STRUCTURE!!!!)

Ok, thanks for the guidance here. I was not aware of this limitation. 

> The secone one is against a clean 2.6.6-rc3 kernel that has 
> your latest
> version + my changes.
> 
> If you approve of my changes, I'd be glad to add the driver to my bk
> trees to have it show up in the next -mm release, and I will 
> push it off
> to Linus after 2.6.6 is out.  Sound ok?

This looks good. I'll do a quick compile/boot check. I would really 
appreciate your help in getting this in. (although I was hoping to get
it into 2.6.6, I guess it can wait for 2.6.7 :-)
--
Michael

Re: [BK PATCH] add SMBIOS tables to sysfs

[Greg KH]

On Wed, Apr 28, 2004 at 12:18:21PM -0500, Michael_E_Brown@Dell.com wrote:
> > -----Original Message-----
> > From: Greg KH [mailto:greg@kroah.com] 
> > 
> > Ok, here are 2 patches.  The first small one is on top of your latest
> > version.  It gets rid of the extra subdirectory, and removes the
> > unneeded kobject from your static structure (NEVER USE A KOBJECT IN A
> > STATIC STRUCTURE!!!!)
> 
> Ok, thanks for the guidance here. I was not aware of this limitation. 

{sigh} I think I need to update the documentation...

> > The secone one is against a clean 2.6.6-rc3 kernel that has 
> > your latest
> > version + my changes.
> > 
> > If you approve of my changes, I'd be glad to add the driver to my bk
> > trees to have it show up in the next -mm release, and I will 
> > push it off
> > to Linus after 2.6.6 is out.  Sound ok?
> 
> This looks good. I'll do a quick compile/boot check. I would really 
> appreciate your help in getting this in. (although I was hoping to get
> it into 2.6.6, I guess it can wait for 2.6.7 :-)

Yes, 2.6.6 is too late, sorry.

Let me know if the patch works for you and then I'll add it to my trees.
It worked for me on my box :)

thanks,

greg k-h

RE: [BK PATCH] add SMBIOS tables to sysfs

[Michael_E_Brown]

Looks good. You can go ahead and add it to your tree. 

I do have one question, though. Here:

> +static struct kobj_type ktype_smbios = {
> +	.sysfs_ops	= &smbios_attr_ops,
> +	.default_attrs	= def_attrs,
> +	/* statically allocated, no release method necessary */
> +};

I have no .release method because I have not kmalloc'ed any 
instances of this struct. Do I need to re-add a release
method here?
--
Michael

Re: [BK PATCH] add SMBIOS tables to sysfs

[Greg KH]

On Wed, Apr 28, 2004 at 12:37:19PM -0500, Michael_E_Brown@Dell.com wrote:
> Looks good. You can go ahead and add it to your tree. 

Ok, will do, thanks for testing.

> I do have one question, though. Here:
> 
> > +static struct kobj_type ktype_smbios = {
> > +	.sysfs_ops	= &smbios_attr_ops,
> > +	.default_attrs	= def_attrs,
> > +	/* statically allocated, no release method necessary */
> > +};
> 
> I have no .release method because I have not kmalloc'ed any 
> instances of this struct. Do I need to re-add a release
> method here?

No, you are ok here.  Static kobj_type structures are ok for 2.6.  For
2.7 we will probably fix up all of this properly, we've learned a lot in
the past few years :)

thanks,

greg k-h

[BK PATCH] add SMBIOS tables to sysfs

[Michael Brown]

Andrew,
	Below is a short patch to add SMBIOS data to sysfs. It it against latest
bitkeeper 2.6.6-rc (specifically, it applies after the efivars patch that
recently went in) but should apply to any recent kernel with only minor 
reject on drivers/firmware/Makefile. A version for 2.4 (using /proc) will
follow tomorrow.

	--Rationale--

	In the past, systems management applications that wanted to parse the 
SMBIOS tables used the /dev/mem interface to directly read the table 
header + data from physical memory. The spec says that the table header 
(sometimes referred to as the table entry point) should be somewhere in memory 
between 0xF0000 and 0xFFFFF. The table header contains a 32-bit pointer to the 
table proper. Up until this point, most BIOS implementations put the actual 
table in F-block as well.

	This is changing. Many systems want to do dynamic SMBIOS tables, and some 
systems are running out of memory in F-block to store the table. On these 
systems, the actual SMBIOS table is typically in high memory somewhere in an 
E820 reserved section. The normal /dev/mem driver will not allow access to 
these regions.

	Next, in Red Hat 2.6 kernels, the /dev/mem interface has been restricted 
so that it will only allow access to the first 1MB of RAM for security purposes. 

	And last, access to /dev/mem is allowed only to users with CAP_SYS_RAWIO.

	So, to get around these restrictions here is a small SMBIOS driver that 
presents existing SMBIOS information as files in sysfs. It creates 
/sys/firmware/smbios/smbios/table_entry_point, and 
/sys/firmware/smbios/smbios/table. These files are binary-mode files that 
contain the raw contents of the table entry point and table, respectively. 
These files can easily be parsed by userspace apps.

--
Michael Brown


# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
#   2004/04/27 20:27:21-05:00 mebrown@michaels-house.net 
#   Add sysfs driver to present SMBIOS data
# 
# drivers/firmware/smbios.h
#   2004/04/27 20:25:16-05:00 mebrown@michaels-house.net +53 -0
# 
# drivers/firmware/smbios.h
#   2004/04/27 20:25:16-05:00 mebrown@michaels-house.net +0 -0
#   BitKeeper file /home/michael_e_brown/kernel/bk/subtrees/smbios-driver-work2/drivers/firmware/smbios.h
# 
# drivers/firmware/smbios.c
#   2004/04/27 20:25:15-05:00 mebrown@michaels-house.net +266 -0
# 
# drivers/firmware/smbios.c
#   2004/04/27 20:25:15-05:00 mebrown@michaels-house.net +0 -0
#   BitKeeper file /home/michael_e_brown/kernel/bk/subtrees/smbios-driver-work2/drivers/firmware/smbios.c
# 
# drivers/firmware/Makefile
#   2004/04/27 20:25:15-05:00 mebrown@michaels-house.net +1 -0
#   add SMBIOS to build system
# 
# drivers/firmware/Kconfig
#   2004/04/27 20:25:15-05:00 mebrown@michaels-house.net +8 -0
#   Add SMBIOS sysfs config option
# 
diff -Nru a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
--- a/drivers/firmware/Kconfig	Tue Apr 27 20:28:39 2004
+++ b/drivers/firmware/Kconfig	Tue Apr 27 20:28:39 2004
@@ -34,4 +34,12 @@
 	  Subsequent efibootmgr releases may be found at:
 	  http://linux.dell.com/efibootmgr
 
+config SMBIOS
+	tristate "BIOS SMBIOS table access driver."
+	help
+	  Say Y or M here if you want to enable access to the SMBIOS table
+	  via driverfs. It exposes /sys/firmware/smbios/ subdirectory tree
+	  containing a binary dump of the SMBIOS table header as well as the SMBIOS
+	  table.
+
 endmenu
diff -Nru a/drivers/firmware/Makefile b/drivers/firmware/Makefile
--- a/drivers/firmware/Makefile	Tue Apr 27 20:28:39 2004
+++ b/drivers/firmware/Makefile	Tue Apr 27 20:28:39 2004
@@ -3,3 +3,4 @@
 #
 obj-$(CONFIG_EDD)             	+= edd.o
 obj-$(CONFIG_EFI_VARS)		+= efivars.o
+obj-$(CONFIG_SMBIOS)            += smbios.o
diff -Nru a/drivers/firmware/smbios.c b/drivers/firmware/smbios.c
--- /dev/null	Wed Dec 31 16:00:00 1969
+++ b/drivers/firmware/smbios.c	Tue Apr 27 20:28:39 2004
@@ -0,0 +1,266 @@
+/*
+ * linux/drivers/firmware/smbios.c
+ *  Copyright (C) 2002, 2003, 2004 Dell Inc.
+ *  by Michael Brown <Michael_E_Brown@dell.com>
+ *  vim:noet:ts=8:sw=8:filetype=c:textwidth=80:
+ *
+ * BIOS SMBIOS Table access
+ * conformant to DMTF SMBIOS definition
+ *   at http://www.dmtf.org/standards/smbios
+ *
+ * This code takes information provided by SMBIOS tables
+ * and presents it in sysfs as:
+ *    /sys/firmware/smbios/smbios
+ *				|--> /table_entry_point
+ *				|--> /table
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License v2.0 as published by
+ * the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include "smbios.h"
+
+MODULE_AUTHOR("Michael Brown <Michael_E_Brown@Dell.com>");
+MODULE_DESCRIPTION("sysfs interface to SMBIOS information");
+MODULE_LICENSE("GPL");
+
+#define SMBIOS_VERSION "1.0 2004-04-19"
+
+struct smbios_device {
+	struct smbios_table_entry_point table_eps;
+	unsigned int smbios_table_real_length;
+	struct kobject kobj;
+};
+
+/* there shall be only one */
+static struct smbios_device the_smbios_device;
+
+#define to_smbios_device(obj) container_of(obj,struct smbios_device,kobj)
+
+/* don't currently have any "normal" attributes, so we don't need a way to
+ * show them. */
+static struct sysfs_ops smbios_attr_ops = { };
+
+static __init int
+checksum_eps(struct smbios_table_entry_point *table_eps)
+{
+	u8 *p = (u8 *)table_eps;
+	u8 checksum = 0;
+	int i=0;
+	for (i=0; i < table_eps->eps_length && i < sizeof(*table_eps); ++i) {
+		checksum += p[i];
+	}
+	return( checksum == 0 );
+}
+
+static __init int
+find_table_entry_point(struct smbios_device *sdev)
+{
+	struct smbios_table_entry_point *table_eps = &(sdev->table_eps);
+	u32 fp = 0xF0000;
+	while (fp < 0xFFFFF) {
+		isa_memcpy_fromio(table_eps, fp, sizeof(*table_eps));
+		if (memcmp(table_eps->anchor, "_SM_", 4)==0 &&
+					checksum_eps(table_eps)) {
+			return 0;
+		}
+		fp += 16;
+	}
+
+	printk(KERN_INFO "SMBIOS table entry point not found in "
+			"0xF0000 - 0xFFFFF\n");
+	return -ENODEV;
+}
+
+static __init int
+find_table_max_address(struct smbios_device *sdev)
+{
+	/* break out on one of three conditions:
+	 *   -- hit table_eps.table_length
+	 *   -- hit number of items that table claims we have
+	 *   -- hit structure type 127
+	 */
+
+	u8 *buf = ioremap(sdev->table_eps.table_address,
+			sdev->table_eps.table_length);
+	u8 *ptr = buf;
+	int count = 0, keep_going = 1;
+	int max_count = sdev->table_eps.table_num_structs;
+	int max_length = sdev->table_eps.table_length;
+	while(keep_going && ((ptr - buf) <= max_length) && count < max_count){
+		if( ptr[0] == 0x7F )   /* ptr[0] is type */
+			keep_going = 0;
+
+		ptr += ptr[1]; /* ptr[1] is length, skip structure */
+		/* skip strings at end of structure */
+		while((ptr-buf) < max_length && (ptr[0] || ptr[1]))
+			++ptr;
+
+		/* string area ends in double-null. skip it. */
+		ptr += 2;
+		++count;
+	}
+	sdev->smbios_table_real_length = (ptr - buf);
+	iounmap(buf);
+
+	if( count != max_count )
+		printk(KERN_INFO "Warning: SMBIOS table structure count"
+				" does not match count specified in the"
+				" table entry point.\n"
+				" Table entry point count: %d\n"
+				" Actual count: %d\n",
+				max_count, count );
+
+	if(keep_going != 0)
+		printk(KERN_INFO "Warning: SMBIOS table does not end with a"
+				" structure type 127. This may indicate a"
+				" truncated table.");
+
+	if(sdev->smbios_table_real_length != max_length)
+		printk(KERN_INFO "Warning: BIOS specified SMBIOS table length"
+				" does not match calculated length.\n"
+				" BIOS specified: %d\n"
+				" calculated length: %d\n",
+				max_length, sdev->smbios_table_real_length);
+
+	return sdev->smbios_table_real_length;
+}
+
+static ssize_t
+smbios_read_table_entry_point(struct kobject *kobj, char *buffer,
+				loff_t pos, size_t size)
+{
+	struct smbios_device *sdev = to_smbios_device(kobj);
+	const char *p = (const char *)&(sdev->table_eps);
+	unsigned int count =
+		size > sizeof(sdev->table_eps) ?
+			sizeof(sdev->table_eps) : size;
+	memcpy( buffer, p, count );
+	return count;
+}
+
+static ssize_t
+smbios_read_table(struct kobject *kobj, char *buffer,
+				loff_t pos, size_t size)
+{
+	struct smbios_device *sdev = to_smbios_device(kobj);
+	u8 *buf;
+	unsigned int count = sdev->smbios_table_real_length - pos;
+	int i = 0;
+	count = count < size ? count : size;
+
+	if (pos > sdev->smbios_table_real_length)
+		return 0;
+
+	buf = ioremap(sdev->table_eps.table_address, sdev->smbios_table_real_length);
+	if (buf == NULL)
+		return -ENXIO;
+
+	/* memcpy( buffer, buf+pos, count ); */
+	for (i = 0; i < count; ++i) {
+		buffer[i] = readb( buf+pos+i );
+	}
+
+	iounmap(buf);
+
+	return count;
+}
+
+static struct bin_attribute tep_attr = {
+	.attr = {.name = "table_entry_point", .owner = THIS_MODULE, .mode = 0444},
+	.size = sizeof(struct smbios_table_entry_point),
+	.read = smbios_read_table_entry_point,
+	/* not writeable */
+};
+
+static struct bin_attribute table_attr = {
+	.attr = { .name = "table", .owner = THIS_MODULE, .mode = 0444 },
+	/* size set later, we don't know it here. */
+	.read = smbios_read_table,
+	/* not writeable */
+};
+
+/* no default attributes yet. */
+static struct attribute * def_attrs[] = { NULL, };
+
+static struct kobj_type ktype_smbios = {
+	.sysfs_ops	= &smbios_attr_ops,
+	.default_attrs	= def_attrs,
+	/* statically allocated, no release method necessary */
+};
+
+static decl_subsys(smbios,&ktype_smbios,NULL);
+
+static inline void
+smbios_device_unregister(struct smbios_device *sdev)
+{
+	sysfs_remove_bin_file(&sdev->kobj, &tep_attr );
+	sysfs_remove_bin_file(&sdev->kobj, &table_attr );
+	kobject_unregister(&sdev->kobj);
+}
+
+static int
+smbios_device_register(struct smbios_device *sdev)
+{
+	int error;
+
+	if (!sdev)
+		return 1;
+
+	snprintf(sdev->kobj.name, 7, "smbios" );
+	kobj_set_kset_s(sdev,smbios_subsys);
+	error = kobject_register(&sdev->kobj);
+	if (!error){
+		sysfs_create_bin_file(&sdev->kobj, &tep_attr );
+		sysfs_create_bin_file(&sdev->kobj, &table_attr );
+	}
+	return error;
+}
+
+static int __init
+smbios_init(void)
+{
+	int rc=0;
+
+	printk(KERN_INFO "SMBIOS facility v%s\n", SMBIOS_VERSION );
+
+	rc = find_table_entry_point(&the_smbios_device);
+	if (rc)
+		return rc;
+
+	table_attr.size = find_table_max_address(&the_smbios_device);
+
+	rc = firmware_register(&smbios_subsys);
+	if (rc)
+		return rc;
+
+	rc = smbios_device_register(&the_smbios_device);
+
+	if (rc)
+		firmware_unregister(&smbios_subsys);
+
+	return rc;
+}
+
+static void __exit
+smbios_exit(void)
+{
+	smbios_device_unregister(&the_smbios_device);
+	firmware_unregister(&smbios_subsys);
+}
+
+late_initcall(smbios_init);
+module_exit(smbios_exit);
diff -Nru a/drivers/firmware/smbios.h b/drivers/firmware/smbios.h
--- /dev/null	Wed Dec 31 16:00:00 1969
+++ b/drivers/firmware/smbios.h	Tue Apr 27 20:28:39 2004
@@ -0,0 +1,53 @@
+/*
+ * linux/drivers/firmware/smbios.c
+ *  Copyright (C) 2002, 2003, 2004 Dell Inc.
+ *  by Michael Brown <Michael_E_Brown@dell.com>
+ *  vim:noet:ts=8:sw=8:filetype=c:textwidth=80:
+ *
+ * BIOS SMBIOS Table access 
+ * conformant to DMTF SMBIOS definition
+ *   at http://www.dmtf.org/standards/smbios
+ *
+ * This code takes information provided by SMBIOS tables
+ * and presents it in sysfs.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License v2.0 as published by
+ * the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _LINUX_SMBIOS_H
+#define _LINUX_SMBIOS_H
+
+#include <linux/types.h>
+
+struct smbios_table_entry_point {
+	u8 anchor[4];
+	u8 checksum;
+	u8 eps_length;
+	u8 major_ver;
+	u8 minor_ver;
+	u16 max_struct_size;
+	u8 revision;
+	u8 formatted_area[5];
+	u8 dmi_anchor[5];
+	u8 intermediate_checksum;
+	u16 table_length;
+	u32 table_address;
+	u16 table_num_structs;
+	u8 smbios_bcd_revision;
+} __attribute__ ((packed));
+
+struct smbios_structure_header {
+	u8 type;
+	u8 length;
+	u16 handle;
+} __attribute__ ((packed));
+
+#endif				/* _LINUX_SMBIOS_H */

Re: [BK PATCH] add SMBIOS tables to sysfs

[Greg KH]

On Tue, Apr 27, 2004 at 09:27:49PM -0500, Michael Brown wrote:
> Andrew,
> 	Below is a short patch to add SMBIOS data to sysfs. It it against latest
> bitkeeper 2.6.6-rc (specifically, it applies after the efivars patch that
> recently went in) but should apply to any recent kernel with only minor 
> reject on drivers/firmware/Makefile. A version for 2.4 (using /proc) will
> follow tomorrow.

Nice idea and patch.  A few minor comments:

> /sys/firmware/smbios/smbios/table_entry_point
> /sys/firmware/smbios/smbios/table

Why repeat the "smbios" directory?  Is this a limitation in the sysfs
interface right now?  Or are you going to put more files in the main
smbios directory some day?

> +	snprintf(sdev->kobj.name, 7, "smbios" );

Try using kobject_set_name() instead, it will do the proper thing if the
string is bigger than the base kobj.name field.

thanks,

greg k-h

Re: [BK PATCH] add SMBIOS tables to sysfs

[Michael Brown]

On Tue, 2004-04-27 at 22:30, Greg KH wrote:
> Nice idea and patch.  A few minor comments:

Thank you.

> 
> > /sys/firmware/smbios/smbios/table_entry_point
> > /sys/firmware/smbios/smbios/table
> 
> Why repeat the "smbios" directory?  Is this a limitation in the sysfs
> interface right now?  Or are you going to put more files in the main
> smbios directory some day?

>From what I could tell (please correct me if I am wrong), you can add
only subsystems to the firmware directory. The first "smbios" is for the
subsystem. Then, you can only add devices to the subsystem. The second
"smbios" is for the device.

I really would like to get rid of one myself, but it was not obvious to
me how to do this. No, I do not plan on adding new objects in there.

> 
> > +	snprintf(sdev->kobj.name, 7, "smbios" );
> 
> Try using kobject_set_name() instead, it will do the proper thing if the
> string is bigger than the base kobj.name field.

Ok, thanks.
Thanks,
Michael

Re: [BK PATCH] add SMBIOS tables to sysfs

[Greg KH]

On Tue, Apr 27, 2004 at 10:38:35PM -0500, Michael Brown wrote:
> On Tue, 2004-04-27 at 22:30, Greg KH wrote:
> > 
> > > /sys/firmware/smbios/smbios/table_entry_point
> > > /sys/firmware/smbios/smbios/table
> > 
> > Why repeat the "smbios" directory?  Is this a limitation in the sysfs
> > interface right now?  Or are you going to put more files in the main
> > smbios directory some day?
> 
> >From what I could tell (please correct me if I am wrong), you can add
> only subsystems to the firmware directory. The first "smbios" is for the
> subsystem. Then, you can only add devices to the subsystem. The second
> "smbios" is for the device.
> 
> I really would like to get rid of one myself, but it was not obvious to
> me how to do this. No, I do not plan on adding new objects in there.

Ok, here are 2 patches.  The first small one is on top of your latest
version.  It gets rid of the extra subdirectory, and removes the
unneeded kobject from your static structure (NEVER USE A KOBJECT IN A
STATIC STRUCTURE!!!!)

The secone one is against a clean 2.6.6-rc3 kernel that has your latest
version + my changes.

If you approve of my changes, I'd be glad to add the driver to my bk
trees to have it show up in the next -mm release, and I will push it off
to Linus after 2.6.6 is out.  Sound ok?

thanks,

greg k-h

----------------------------------
# My cleanups to the smbios driver.

diff -Nru a/drivers/firmware/smbios.c b/drivers/firmware/smbios.c
--- a/drivers/firmware/smbios.c	Wed Apr 28 09:45:59 2004
+++ b/drivers/firmware/smbios.c	Wed Apr 28 09:45:59 2004
@@ -10,9 +10,9 @@
  *
  * This code takes information provided by SMBIOS tables
  * and presents it in sysfs as:
- *    /sys/firmware/smbios/smbios
- *				|--> /table_entry_point
- *				|--> /table
+ *    /sys/firmware/smbios
+ *			|--> /table_entry_point
+ *			|--> /table
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License v2.0 as published by
@@ -42,7 +42,6 @@
 struct smbios_device {
 	struct smbios_table_entry_point table_eps;
 	unsigned int smbios_table_real_length;
-	struct kobject kobj;
 };
 
 /* there shall be only one */
@@ -143,7 +142,7 @@
 smbios_read_table_entry_point(struct kobject *kobj, char *buffer,
 				loff_t pos, size_t size)
 {
-	struct smbios_device *sdev = to_smbios_device(kobj);
+	struct smbios_device *sdev = &the_smbios_device;
 	const char *p = (const char *)&(sdev->table_eps);
 	unsigned int count =
 		size > sizeof(sdev->table_eps) ?
@@ -156,7 +155,7 @@
 smbios_read_table(struct kobject *kobj, char *buffer,
 				loff_t pos, size_t size)
 {
-	struct smbios_device *sdev = to_smbios_device(kobj);
+	struct smbios_device *sdev = &the_smbios_device;
 	u8 *buf;
 	unsigned int count = sdev->smbios_table_real_length - pos;
 	int i = 0;
@@ -204,30 +203,16 @@
 
 static decl_subsys(smbios,&ktype_smbios,NULL);
 
-static inline void
-smbios_device_unregister(struct smbios_device *sdev)
+static void smbios_device_unregister(void)
 {
-	sysfs_remove_bin_file(&sdev->kobj, &tep_attr );
-	sysfs_remove_bin_file(&sdev->kobj, &table_attr );
-	kobject_unregister(&sdev->kobj);
+	sysfs_remove_bin_file(&smbios_subsys.kset.kobj, &tep_attr );
+	sysfs_remove_bin_file(&smbios_subsys.kset.kobj, &table_attr );
 }
 
-static int
-smbios_device_register(struct smbios_device *sdev)
+static void __init smbios_device_register(void)
 {
-	int error;
-
-	if (!sdev)
-		return 1;
-
-	kobject_set_name(&sdev->kobj, "smbios");
-	kobj_set_kset_s(sdev,smbios_subsys);
-	error = kobject_register(&sdev->kobj);
-	if (!error){
-		sysfs_create_bin_file(&sdev->kobj, &tep_attr );
-		sysfs_create_bin_file(&sdev->kobj, &table_attr );
-	}
-	return error;
+	sysfs_create_bin_file(&smbios_subsys.kset.kobj, &tep_attr );
+	sysfs_create_bin_file(&smbios_subsys.kset.kobj, &table_attr );
 }
 
 static int __init
@@ -247,10 +232,7 @@
 	if (rc)
 		return rc;
 
-	rc = smbios_device_register(&the_smbios_device);
-
-	if (rc)
-		firmware_unregister(&smbios_subsys);
+	smbios_device_register();
 
 	return rc;
 }
@@ -258,7 +240,7 @@
 static void __exit
 smbios_exit(void)
 {
-	smbios_device_unregister(&the_smbios_device);
+	smbios_device_unregister();
 	firmware_unregister(&smbios_subsys);
 }
 



----------------------------------

# Whole smbios driver with my cleanup in it.

diff -Nru a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
--- a/drivers/firmware/Kconfig	Wed Apr 28 09:39:53 2004
+++ b/drivers/firmware/Kconfig	Wed Apr 28 09:39:53 2004
@@ -34,4 +34,12 @@
 	  Subsequent efibootmgr releases may be found at:
 	  http://linux.dell.com/efibootmgr
 
+config SMBIOS
+	tristate "BIOS SMBIOS table access driver."
+	help
+	  Say Y or M here if you want to enable access to the SMBIOS table
+	  via driverfs. It exposes /sys/firmware/smbios/ subdirectory tree
+	  containing a binary dump of the SMBIOS table header as well as the SMBIOS
+	  table.
+
 endmenu
diff -Nru a/drivers/firmware/Makefile b/drivers/firmware/Makefile
--- a/drivers/firmware/Makefile	Wed Apr 28 09:39:53 2004
+++ b/drivers/firmware/Makefile	Wed Apr 28 09:39:53 2004
@@ -3,3 +3,4 @@
 #
 obj-$(CONFIG_EDD)             	+= edd.o
 obj-$(CONFIG_EFI_VARS)		+= efivars.o
+obj-$(CONFIG_SMBIOS)            += smbios.o
diff -Nru a/drivers/firmware/smbios.c b/drivers/firmware/smbios.c
--- /dev/null	Wed Dec 31 16:00:00 1969
+++ b/drivers/firmware/smbios.c	Wed Apr 28 09:39:53 2004
@@ -0,0 +1,248 @@
+/*
+ * linux/drivers/firmware/smbios.c
+ *  Copyright (C) 2004 Dell Inc.
+ *  by Michael Brown <Michael_E_Brown@dell.com>
+ *  vim:noet:ts=8:sw=8:filetype=c:textwidth=80:
+ *
+ * BIOS SMBIOS Table access
+ * conformant to DMTF SMBIOS definition
+ *   at http://www.dmtf.org/standards/smbios
+ *
+ * This code takes information provided by SMBIOS tables
+ * and presents it in sysfs as:
+ *    /sys/firmware/smbios
+ *			|--> /table_entry_point
+ *			|--> /table
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License v2.0 as published by
+ * the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include "smbios.h"
+
+MODULE_AUTHOR("Michael Brown <Michael_E_Brown@Dell.com>");
+MODULE_DESCRIPTION("sysfs interface to SMBIOS information");
+MODULE_LICENSE("GPL");
+
+#define SMBIOS_VERSION "1.0 2004-04-19"
+
+struct smbios_device {
+	struct smbios_table_entry_point table_eps;
+	unsigned int smbios_table_real_length;
+};
+
+/* there shall be only one */
+static struct smbios_device the_smbios_device;
+
+#define to_smbios_device(obj) container_of(obj,struct smbios_device,kobj)
+
+/* don't currently have any "normal" attributes, so we don't need a way to
+ * show them. */
+static struct sysfs_ops smbios_attr_ops = { };
+
+static __init int
+checksum_eps(struct smbios_table_entry_point *table_eps)
+{
+	u8 *p = (u8 *)table_eps;
+	u8 checksum = 0;
+	int i=0;
+	for (i=0; i < table_eps->eps_length && i < sizeof(*table_eps); ++i) {
+		checksum += p[i];
+	}
+	return( checksum == 0 );
+}
+
+static __init int
+find_table_entry_point(struct smbios_device *sdev)
+{
+	struct smbios_table_entry_point *table_eps = &(sdev->table_eps);
+	u32 fp = 0xF0000;
+	while (fp < 0xFFFFF) {
+		isa_memcpy_fromio(table_eps, fp, sizeof(*table_eps));
+		if (memcmp(table_eps->anchor, "_SM_", 4)==0 &&
+					checksum_eps(table_eps)) {
+			return 0;
+		}
+		fp += 16;
+	}
+
+	printk(KERN_INFO "SMBIOS table entry point not found in "
+			"0xF0000 - 0xFFFFF\n");
+	return -ENODEV;
+}
+
+static __init int
+find_table_max_address(struct smbios_device *sdev)
+{
+	/* break out on one of three conditions:
+	 *   -- hit table_eps.table_length
+	 *   -- hit number of items that table claims we have
+	 *   -- hit structure type 127
+	 */
+
+	u8 *buf = ioremap(sdev->table_eps.table_address,
+			sdev->table_eps.table_length);
+	u8 *ptr = buf;
+	int count = 0, keep_going = 1;
+	int max_count = sdev->table_eps.table_num_structs;
+	int max_length = sdev->table_eps.table_length;
+	while(keep_going && ((ptr - buf) <= max_length) && count < max_count){
+		if( ptr[0] == 0x7F )   /* ptr[0] is type */
+			keep_going = 0;
+
+		ptr += ptr[1]; /* ptr[1] is length, skip structure */
+		/* skip strings at end of structure */
+		while((ptr-buf) < max_length && (ptr[0] || ptr[1]))
+			++ptr;
+
+		/* string area ends in double-null. skip it. */
+		ptr += 2;
+		++count;
+	}
+	sdev->smbios_table_real_length = (ptr - buf);
+	iounmap(buf);
+
+	if( count != max_count )
+		printk(KERN_INFO "Warning: SMBIOS table structure count"
+				" does not match count specified in the"
+				" table entry point.\n"
+				" Table entry point count: %d\n"
+				" Actual count: %d\n",
+				max_count, count );
+
+	if(keep_going != 0)
+		printk(KERN_INFO "Warning: SMBIOS table does not end with a"
+				" structure type 127. This may indicate a"
+				" truncated table.");
+
+	if(sdev->smbios_table_real_length != max_length)
+		printk(KERN_INFO "Warning: BIOS specified SMBIOS table length"
+				" does not match calculated length.\n"
+				" BIOS specified: %d\n"
+				" calculated length: %d\n",
+				max_length, sdev->smbios_table_real_length);
+
+	return sdev->smbios_table_real_length;
+}
+
+static ssize_t
+smbios_read_table_entry_point(struct kobject *kobj, char *buffer,
+				loff_t pos, size_t size)
+{
+	struct smbios_device *sdev = &the_smbios_device;
+	const char *p = (const char *)&(sdev->table_eps);
+	unsigned int count =
+		size > sizeof(sdev->table_eps) ?
+			sizeof(sdev->table_eps) : size;
+	memcpy( buffer, p, count );
+	return count;
+}
+
+static ssize_t
+smbios_read_table(struct kobject *kobj, char *buffer,
+				loff_t pos, size_t size)
+{
+	struct smbios_device *sdev = &the_smbios_device;
+	u8 *buf;
+	unsigned int count = sdev->smbios_table_real_length - pos;
+	int i = 0;
+	count = count < size ? count : size;
+
+	if (pos > sdev->smbios_table_real_length)
+		return 0;
+
+	buf = ioremap(sdev->table_eps.table_address, sdev->smbios_table_real_length);
+	if (buf == NULL)
+		return -ENXIO;
+
+	/* memcpy( buffer, buf+pos, count ); */
+	for (i = 0; i < count; ++i) {
+		buffer[i] = readb( buf+pos+i );
+	}
+
+	iounmap(buf);
+
+	return count;
+}
+
+static struct bin_attribute tep_attr = {
+	.attr = {.name = "table_entry_point", .owner = THIS_MODULE, .mode = 0444},
+	.size = sizeof(struct smbios_table_entry_point),
+	.read = smbios_read_table_entry_point,
+	/* not writeable */
+};
+
+static struct bin_attribute table_attr = {
+	.attr = { .name = "table", .owner = THIS_MODULE, .mode = 0444 },
+	/* size set later, we don't know it here. */
+	.read = smbios_read_table,
+	/* not writeable */
+};
+
+/* no default attributes yet. */
+static struct attribute * def_attrs[] = { NULL, };
+
+static struct kobj_type ktype_smbios = {
+	.sysfs_ops	= &smbios_attr_ops,
+	.default_attrs	= def_attrs,
+	/* statically allocated, no release method necessary */
+};
+
+static decl_subsys(smbios,&ktype_smbios,NULL);
+
+static void smbios_device_unregister(void)
+{
+	sysfs_remove_bin_file(&smbios_subsys.kset.kobj, &tep_attr );
+	sysfs_remove_bin_file(&smbios_subsys.kset.kobj, &table_attr );
+}
+
+static void __init smbios_device_register(void)
+{
+	sysfs_create_bin_file(&smbios_subsys.kset.kobj, &tep_attr );
+	sysfs_create_bin_file(&smbios_subsys.kset.kobj, &table_attr );
+}
+
+static int __init
+smbios_init(void)
+{
+	int rc=0;
+
+	printk(KERN_INFO "SMBIOS facility v%s\n", SMBIOS_VERSION );
+
+	rc = find_table_entry_point(&the_smbios_device);
+	if (rc)
+		return rc;
+
+	table_attr.size = find_table_max_address(&the_smbios_device);
+
+	rc = firmware_register(&smbios_subsys);
+	if (rc)
+		return rc;
+
+	smbios_device_register();
+
+	return rc;
+}
+
+static void __exit
+smbios_exit(void)
+{
+	smbios_device_unregister();
+	firmware_unregister(&smbios_subsys);
+}
+
+late_initcall(smbios_init);
+module_exit(smbios_exit);
diff -Nru a/drivers/firmware/smbios.h b/drivers/firmware/smbios.h
--- /dev/null	Wed Dec 31 16:00:00 1969
+++ b/drivers/firmware/smbios.h	Wed Apr 28 09:39:53 2004
@@ -0,0 +1,53 @@
+/*
+ * linux/drivers/firmware/smbios.c
+ *  Copyright (C) 2002, 2003, 2004 Dell Inc.
+ *  by Michael Brown <Michael_E_Brown@dell.com>
+ *  vim:noet:ts=8:sw=8:filetype=c:textwidth=80:
+ *
+ * BIOS SMBIOS Table access 
+ * conformant to DMTF SMBIOS definition
+ *   at http://www.dmtf.org/standards/smbios
+ *
+ * This code takes information provided by SMBIOS tables
+ * and presents it in sysfs.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License v2.0 as published by
+ * the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _LINUX_SMBIOS_H
+#define _LINUX_SMBIOS_H
+
+#include <linux/types.h>
+
+struct smbios_table_entry_point {
+	u8 anchor[4];
+	u8 checksum;
+	u8 eps_length;
+	u8 major_ver;
+	u8 minor_ver;
+	u16 max_struct_size;
+	u8 revision;
+	u8 formatted_area[5];
+	u8 dmi_anchor[5];
+	u8 intermediate_checksum;
+	u16 table_length;
+	u32 table_address;
+	u16 table_num_structs;
+	u8 smbios_bcd_revision;
+} __attribute__ ((packed));
+
+struct smbios_structure_header {
+	u8 type;
+	u8 length;
+	u16 handle;
+} __attribute__ ((packed));
+
+#endif				/* _LINUX_SMBIOS_H */

Re: [BK PATCH] add SMBIOS tables to sysfs

[Michael Brown]

On Tue, 2004-04-27 at 22:30, Greg KH wrote:
> > +	snprintf(sdev->kobj.name, 7, "smbios" );
> 
> Try using kobject_set_name() instead, it will do the proper thing if the
> string is bigger than the base kobj.name field.

Looks like this API was added in Aug03. A quick grep through the tree
shows only <10 users. Are there patches pending to convert others, or
are you just having new stuff do this? I know of at least one sysfs
driver (edd) that uses snprintf() that could be converted. I'll send an
updated patch shortly for smbios.c, just curious.

--
Michael

Re: [BK PATCH] add SMBIOS tables to sysfs

[Greg KH]

On Tue, Apr 27, 2004 at 10:55:52PM -0500, Michael Brown wrote:
> On Tue, 2004-04-27 at 22:30, Greg KH wrote:
> > > +	snprintf(sdev->kobj.name, 7, "smbios" );
> > 
> > Try using kobject_set_name() instead, it will do the proper thing if the
> > string is bigger than the base kobj.name field.
> 
> Looks like this API was added in Aug03. A quick grep through the tree
> shows only <10 users. Are there patches pending to convert others, or
> are you just having new stuff do this?

New stuff should use it, and if you want to convert any current code to
also use it, please feel free to, I'll gladly take those patches.

thanks,

greg k-h