ChangeSet 1.1587.5.11, 2004/04/28 11:50:29-07:00, Michael_E_Brown@Dell.com [PATCH] add SMBIOS tables to sysfs -- UPDATED drivers/firmware/Kconfig | 8 + drivers/firmware/Makefile | 1 drivers/firmware/smbios.c | 266 ++++++++++++++++++++++++++++++++++++++++++++++ drivers/firmware/smbios.h | 53 +++++++++ 4 files changed, 328 insertions(+) diff -Nru a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig --- a/drivers/firmware/Kconfig Fri May 14 16:00:10 2004 +++ b/drivers/firmware/Kconfig Fri May 14 16:00:10 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 Fri May 14 16:00:10 2004 +++ b/drivers/firmware/Makefile Fri May 14 16:00:10 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 Fri May 14 16:00:10 2004 @@ -0,0 +1,266 @@ +/* + * linux/drivers/firmware/smbios.c + * Copyright (C) 2004 Dell Inc. + * by Michael Brown + * 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 +#include +#include +#include +#include +#include "smbios.h" + +MODULE_AUTHOR("Michael Brown "); +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; + + 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; +} + +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 Fri May 14 16:00:10 2004 @@ -0,0 +1,53 @@ +/* + * linux/drivers/firmware/smbios.c + * Copyright (C) 2002, 2003, 2004 Dell Inc. + * by Michael Brown + * 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 + +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 */