Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755356AbbDTScf (ORCPT ); Mon, 20 Apr 2015 14:32:35 -0400 Received: from mail-la0-f50.google.com ([209.85.215.50]:34570 "EHLO mail-la0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753860AbbDTSc3 (ORCPT ); Mon, 20 Apr 2015 14:32:29 -0400 MIME-Version: 1.0 In-Reply-To: <1429525187-3376-3-git-send-email-ivan.khoronzhuk@globallogic.com> References: <1429525187-3376-1-git-send-email-ivan.khoronzhuk@globallogic.com> <1429525187-3376-3-git-send-email-ivan.khoronzhuk@globallogic.com> Date: Mon, 20 Apr 2015 11:32:28 -0700 Message-ID: Subject: Re: [Patch v2 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, Mike Waychison , 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: 10219 Lines: 271 On Mon, Apr 20, 2015 at 3:19 AM, 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. > > Signed-off-by: Ivan Khoronzhuk Tested-by: Roy Franz Tested with dmidecode w/patches to read tables from sysfs. The dmidecode patches are posted on dmidecode-devel and should be commited upstream soon. Thanks, Roy > --- > .../ABI/testing/sysfs-firmware-dmi-tables | 22 ++++++ > drivers/firmware/dmi-sysfs.c | 17 +++-- > drivers/firmware/dmi_scan.c | 82 ++++++++++++++++++++++ > include/linux/dmi.h | 2 + > 4 files changed, 114 insertions(+), 9 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..ff3cac8 > --- /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 and 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 binary attributes and are accessible via: > + > + /sys/firmware/dmi/tables/smbios_entry_point > + /sys/firmware/dmi/tables/DMI > + > + The complete DMI information can be obtained using these two > + tables. > diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysfs.c > index e0f1cb3..ef76e5e 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 */ > @@ -648,17 +647,20 @@ static void cleanup_entry_list(void) > > static int __init dmi_sysfs_init(void) > { > - int error = -ENOMEM; > + int error; > 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 = -ENODATA; > goto err; > + } > > dmi_kset = kset_create_and_add("entries", NULL, dmi_kobj); > - if (!dmi_kset) > + if (!dmi_kset) { > + error = -ENOMEM; > goto err; > + } > > val = 0; > error = dmi_walk(dmi_sysfs_register_handle, &val); > @@ -675,7 +677,6 @@ static int __init dmi_sysfs_init(void) > err: > cleanup_entry_list(); > kset_unregister(dmi_kset); > - kobject_put(dmi_kobj); > return error; > } > > @@ -685,8 +686,6 @@ 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 a864a6b..9705be2 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(): > */ > @@ -478,6 +484,8 @@ 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) { > @@ -512,6 +520,9 @@ static int __init dmi_present(const u8 *buf) > pr_info("SMBIOS %d.%d present.\n", > dmi_ver >> 8, dmi_ver & 0xFF); > } else { > + smbios_entry_point_size = 15; > + memcpy(smbios_entry_point, buf, > + smbios_entry_point_size); > pr_info("Legacy DMI %d.%d present.\n", > dmi_ver >> 8, dmi_ver & 0xFF); > } > @@ -538,6 +549,8 @@ static int __init dmi_smbios3_present(const u8 *buf) > dmi_num = 0; /* No longer specified */ > 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); > > if (dmi_walk_early(dmi_decode) == 0) { > pr_info("SMBIOS %d.%d.%d present.\n", > @@ -629,6 +642,75 @@ 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); > +static BIN_ATTR(DMI, S_IRUSR, raw_table_read, NULL, 0); > + > +static int __init dmi_init(void) > +{ > + int ret; > + u8 *dmi_table = NULL; > + struct kobject *tables_kobj = NULL; > + > + if (!dmi_available) { > + ret = -ENODATA; > + goto err; > + } > + > + /* > + * Set up dmi directory at /sys/firmware/dmi. This entry should stay > + * even after farther error, as it can be used by other modules like > + * dmi-sysfs. > + */ > + dmi_kobj = kobject_create_and_add("dmi", firmware_kobj); > + tables_kobj = kobject_create_and_add("tables", dmi_kobj); > + if (!(dmi_kobj && tables_kobj)) { > + ret = -ENOMEM; > + 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) { > + ret = -ENOMEM; > + goto err; > + } > + > + bin_attr_DMI.size = dmi_len; > + bin_attr_DMI.private = dmi_table; > + ret = sysfs_create_bin_file(tables_kobj, &bin_attr_DMI); > + if (!ret) > + 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); > + } > + > + if (dmi_table) > + dmi_unmap(dmi_table); > + > + 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..2f9f988 100644 > --- a/include/linux/dmi.h > +++ b/include/linux/dmi.h > @@ -2,6 +2,7 @@ > #define __DMI_H__ > > #include > +#include > #include > > /* enum dmi_field is in mod_devicetable.h */ > @@ -93,6 +94,7 @@ 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); > -- > 1.9.1 > -- 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/