Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964817AbbDOET1 (ORCPT ); Wed, 15 Apr 2015 00:19:27 -0400 Received: from mail-lb0-f175.google.com ([209.85.217.175]:36280 "EHLO mail-lb0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964798AbbDOETT (ORCPT ); Wed, 15 Apr 2015 00:19:19 -0400 MIME-Version: 1.0 In-Reply-To: <551E5F0B.6050709@globallogic.com> References: <1427979423-22767-1-git-send-email-ivan.khoronzhuk@globallogic.com> <1427979423-22767-3-git-send-email-ivan.khoronzhuk@globallogic.com> <551E5F0B.6050709@globallogic.com> Date: Tue, 14 Apr 2015 21:19:17 -0700 Message-ID: Subject: Re: [Patch 2/3] firmware: dmi_scan: add SBMIOS entry and DMI tables From: Roy Franz To: "Ivan.khoronzhuk" Cc: Linux Kernel Mailing List , Matt Fleming , Jean Delvare , Ard Biesheuvel , Grant Likely , linux-api@vger.kernel.org, linux-doc@vger.kernel.org, mikew@google.com, dmidecode-devel@nongnu.org, Leif Lindholm , Mark Salter Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10462 Lines: 267 On Fri, Apr 3, 2015 at 2:36 AM, Ivan.khoronzhuk wrote: > > > On 02.04.15 15:57, Ivan Khoronzhuk wrote: >> >> Some utils, like dmidecode and smbios, need to access SMBIOS entry >> table area in order to get information like SMBIOS version, size, etc. >> Currently it's done via /dev/mem. But for situation when /dev/mem >> usage is disabled, the utils have to use dmi sysfs instead, which >> doesn't represent SMBIOS entry and adds code/delay redundancy when direct >> access for table is needed. >> >> So this patch creates dmi/tables and adds SMBIOS entry point to allow >> utils in question to work correctly without /dev/mem. Also patch adds >> raw dmi table to simplify dmi table processing in user space, as >> proposed by Jean Delvare. >> I have made modifications to dmidecode to support this interface, and it works quite nicely for dmidecode. (changes posted to dmidecode-devel list) The only open issue I am aware of is how the SMBIOS v3 entry point will be handled, especially in cases where there is a v2 and a v3 entry point. In principal I think this a good change - are there any other open issues? Thanks, Roy >> Signed-off-by: Ivan Khoronzhuk >> --- >> .../ABI/testing/sysfs-firmware-dmi-tables | 22 ++++++ >> drivers/firmware/dmi-sysfs.c | 11 ++- >> drivers/firmware/dmi_scan.c | 80 >> ++++++++++++++++++++++ >> include/linux/dmi.h | 1 + >> 4 files changed, 107 insertions(+), 7 deletions(-) >> create mode 100644 Documentation/ABI/testing/sysfs-firmware-dmi-tables >> >> diff --git a/Documentation/ABI/testing/sysfs-firmware-dmi-tables >> b/Documentation/ABI/testing/sysfs-firmware-dmi-tables >> new file mode 100644 >> index 0000000..f46158c >> --- /dev/null >> +++ b/Documentation/ABI/testing/sysfs-firmware-dmi-tables >> @@ -0,0 +1,22 @@ >> +What: /sys/firmware/dmi/tables/ >> +Date: April 2015 >> +Contact: Ivan Khoronzhuk >> +Description: >> + The firmware provides DMI structures as a packed list of >> + data referenced by a SMBIOS table entry point. The SMBIOS >> + entry point contains general information, like SMBIOS >> + version, DMI table size, etc. The structure, content and >> + size of SMBIOS entry point is dependent on SMBIOS version. >> + The format of SMBIOS entry point, equal as DMI structures >> + can be read in SMBIOS specification. >> + >> + The dmi/tables provides raw SMBIOS entry point and DMI >> tables >> + through sysfs as an alternative to utilities reading them >> + from /dev/mem. The raw SMBIOS entry point and DMI table >> are >> + presented as raw attributes and are accessible via: >> + >> + /sys/firmware/dmi/tables/smbios_entry_point >> + /sys/firmware/dmi/tables/DMI >> + >> + The complete DMI information can be taken using these two >> + tables. >> diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysfs.c >> index e0f1cb3..8e1a411 100644 >> --- a/drivers/firmware/dmi-sysfs.c >> +++ b/drivers/firmware/dmi-sysfs.c >> @@ -566,7 +566,6 @@ static struct kobj_type dmi_sysfs_entry_ktype = { >> .default_attrs = dmi_sysfs_entry_attrs, >> }; >> -static struct kobject *dmi_kobj; >> static struct kset *dmi_kset; >> /* Global count of all instances seen. Only for setup */ >> @@ -651,10 +650,11 @@ static int __init dmi_sysfs_init(void) >> int error = -ENOMEM; >> int val; >> - /* Set up our directory */ >> - dmi_kobj = kobject_create_and_add("dmi", firmware_kobj); >> - if (!dmi_kobj) >> + if (!dmi_kobj) { >> + pr_err("dmi-sysfs: dmi entry is absent.\n"); >> + error = -ENOSYS; >> goto err; >> + } >> dmi_kset = kset_create_and_add("entries", NULL, dmi_kobj); >> if (!dmi_kset) >> @@ -675,7 +675,6 @@ static int __init dmi_sysfs_init(void) >> err: >> cleanup_entry_list(); >> kset_unregister(dmi_kset); >> - kobject_put(dmi_kobj); >> return error; >> } >> @@ -685,8 +684,6 @@ static void __exit dmi_sysfs_exit(void) >> pr_debug("dmi-sysfs: unloading.\n"); >> cleanup_entry_list(); >> kset_unregister(dmi_kset); >> - kobject_del(dmi_kobj); >> - kobject_put(dmi_kobj); >> } >> module_init(dmi_sysfs_init); >> diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c >> index d3aae09..bb19f8b 100644 >> --- a/drivers/firmware/dmi_scan.c >> +++ b/drivers/firmware/dmi_scan.c >> @@ -10,6 +10,9 @@ >> #include >> #include >> +struct kobject *dmi_kobj; >> +EXPORT_SYMBOL_GPL(dmi_kobj); >> + >> /* >> * DMI stands for "Desktop Management Interface". It is part >> * of and an antecedent to, SMBIOS, which stands for System >> @@ -20,6 +23,9 @@ static const char dmi_empty_string[] = " "; >> static u32 dmi_ver __initdata; >> static u32 dmi_len; >> static u16 dmi_num; >> +static u8 smbios_entry_point[32]; >> +static int smbios_entry_point_size; >> + >> /* >> * Catch too early calls to dmi_check_system(): >> */ >> @@ -118,6 +124,7 @@ static void dmi_decode_table(u8 *buf, >> } >> static phys_addr_t dmi_base; >> +static u8 *dmi_table; >> static int __init dmi_walk_early(void (*decode)(const struct >> dmi_header *, >> void *)) >> @@ -476,6 +483,8 @@ static int __init dmi_present(const u8 *buf) >> if (memcmp(buf, "_SM_", 4) == 0 && >> buf[5] < 32 && dmi_checksum(buf, buf[5])) { >> smbios_ver = get_unaligned_be16(buf + 6); >> + smbios_entry_point_size = buf[5]; >> + memcpy(smbios_entry_point, buf, smbios_entry_point_size); >> /* Some BIOS report weird SMBIOS version, fix that up */ >> switch (smbios_ver) { >> @@ -508,6 +517,9 @@ static int __init dmi_present(const u8 *buf) >> dmi_ver >> 8, dmi_ver & 0xFF, >> (dmi_ver < 0x0300) ? "" : ".x"); >> } else { >> + smbios_entry_point_size = 15; >> + memcpy(smbios_entry_point, buf, >> + smbios_entry_point_size); >> dmi_ver = (buf[14] & 0xF0) << 4 | >> (buf[14] & 0x0F); >> pr_info("Legacy DMI %d.%d present.\n", >> @@ -535,6 +547,8 @@ static int __init dmi_smbios3_present(const u8 *buf) >> dmi_ver &= 0xFFFFFF; >> dmi_len = get_unaligned_le32(buf + 12); >> dmi_base = get_unaligned_le64(buf + 16); >> + smbios_entry_point_size = buf[6]; >> + memcpy(smbios_entry_point, buf, smbios_entry_point_size); >> /* >> * The 64-bit SMBIOS 3.0 entry point no longer has a field >> @@ -638,6 +652,72 @@ void __init dmi_scan_machine(void) >> dmi_initialized = 1; >> } >> +static ssize_t raw_table_read(struct file *file, struct kobject *kobj, >> + struct bin_attribute *attr, char *buf, >> + loff_t pos, size_t count) >> +{ >> + memcpy(buf, attr->private + pos, count); >> + return count; >> +} >> + >> +static BIN_ATTR(smbios_entry_point, S_IRUSR, raw_table_read, NULL, 0); >> +struct bin_attribute bin_attr_dmi_table = >> + __BIN_ATTR(DMI, S_IRUSR, raw_table_read, NULL, 0); > > > missed static here > > >> + >> +static int __init dmi_init(void) >> +{ >> + int ret = -ENOMEM; >> + struct kobject *tables_kobj = NULL; >> + >> + if (!dmi_available) { >> + ret = -ENOSYS; >> + goto err; >> + } >> + >> + /* Set up dmi directory at /sys/firmware/dmi */ >> + dmi_kobj = kobject_create_and_add("dmi", firmware_kobj); >> + if (!dmi_kobj) >> + goto err; >> + >> + tables_kobj = kobject_create_and_add("tables", dmi_kobj); >> + if (!tables_kobj) >> + goto err; >> + >> + bin_attr_smbios_entry_point.size = smbios_entry_point_size; >> + bin_attr_smbios_entry_point.private = smbios_entry_point; >> + ret = sysfs_create_bin_file(tables_kobj, >> &bin_attr_smbios_entry_point); >> + if (ret) >> + goto err; >> + >> + dmi_table = dmi_remap(dmi_base, dmi_len); >> + if (!dmi_table) >> + goto err; >> + >> + bin_attr_dmi_table.size = dmi_len; >> + bin_attr_dmi_table.private = dmi_table; >> + ret = sysfs_create_bin_file(tables_kobj, &bin_attr_dmi_table); >> + if (ret) { >> + dmi_unmap(dmi_table); >> + goto err; >> + } >> + >> + return 0; >> +err: >> + pr_err("dmi: Firmware registration failed.\n"); >> + >> + if (tables_kobj) >> + sysfs_remove_bin_file(tables_kobj, >> + &bin_attr_smbios_entry_point); >> + kobject_del(tables_kobj); >> + kobject_put(tables_kobj); >> + kobject_del(dmi_kobj); >> + kobject_put(dmi_kobj); >> + dmi_kobj = NULL; >> + >> + return ret; >> +} >> +subsys_initcall(dmi_init); >> + >> /** >> * dmi_set_dump_stack_arch_desc - set arch description for dump_stack() >> * >> diff --git a/include/linux/dmi.h b/include/linux/dmi.h >> index f820f0a..9f55f46 100644 >> --- a/include/linux/dmi.h >> +++ b/include/linux/dmi.h >> @@ -93,6 +93,7 @@ struct dmi_dev_onboard { >> int devfn; >> }; >> +extern struct kobject *dmi_kobj; >> extern int dmi_check_system(const struct dmi_system_id *list); >> const struct dmi_system_id *dmi_first_match(const struct dmi_system_id >> *list); >> extern const char * dmi_get_system_info(int field); > > > -- > Regards, > Ivan Khoronzhuk > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/