Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754483AbbBJJvw (ORCPT ); Tue, 10 Feb 2015 04:51:52 -0500 Received: from mail-pa0-f45.google.com ([209.85.220.45]:47675 "EHLO mail-pa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753220AbbBJJvs (ORCPT ); Tue, 10 Feb 2015 04:51:48 -0500 Message-ID: <54D9D4B0.7020803@linaro.org> Date: Tue, 10 Feb 2015 11:51:44 +0200 From: Ivan Khoronzhuk User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: matt@codeblueprint.co.uk, Grant Likely , Ard Biesheuvel CC: "linux-kernel@vger.kernel.org" , linux-api@vger.kernel.org, linux-doc@vger.kernel.org, Leif Lindholm , Mark Salter Subject: Re: [Patch v4] firmware: dmi-sysfs: add SMBIOS entry point area attribute References: <1423069563-26467-1-git-send-email-ivan.khoronzhuk@linaro.org> In-Reply-To: <1423069563-26467-1-git-send-email-ivan.khoronzhuk@linaro.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8160 Lines: 228 Hi Matt, On 02/04/2015 07:06 PM, 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. So this patch adds SMBIOS area to > dmi-sysfs in order to allow utils in question to work correctly with > dmi sysfs interface. > > Reviewed-by: Ard Biesheuvel > Signed-off-by: Ivan Khoronzhuk > --- > > v1: https://lkml.org/lkml/2015/1/23/643 > v2: https://lkml.org/lkml/2015/1/26/345 > v3: https://lkml.org/lkml/2015/1/28/768 > > v4..v2: > firmware: dmi_scan: add symbol to get SMBIOS entry area > - used u8 type for smbios_header var > firmware: dmi-sysfs: add SMBIOS entry point area attribute > - replaced -ENODATA on -EINVAL > > v3..v2: > firmware: dmi_scan: add symbol to get SMBIOS entry area > firmware: dmi-sysfs: add SMBIOS entry point area attribute > - combined in one patch > - added SMBIOS information to ABI sysfs-dmi documentaton > > v2..v1: > firmware: dmi_scan: add symbol to get SMBIOS entry area > - used additional static var to hold SMBIOS raw table size > - changed format of get_smbios_entry_area symbol > returned pointer on const smbios table > > firmware: dmi-sysfs: add SMBIOS entry point area attribute > - adopted to updated get_smbios_entry_area symbol > - removed redundant array to save smbios table > > Documentation/ABI/testing/sysfs-firmware-dmi | 10 +++++++ > drivers/firmware/dmi-sysfs.c | 42 ++++++++++++++++++++++++++++ > drivers/firmware/dmi_scan.c | 26 +++++++++++++++++ > include/linux/dmi.h | 3 ++ > 4 files changed, 81 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-firmware-dmi b/Documentation/ABI/testing/sysfs-firmware-dmi > index c78f9ab..3a9ffe8 100644 > --- a/Documentation/ABI/testing/sysfs-firmware-dmi > +++ b/Documentation/ABI/testing/sysfs-firmware-dmi > @@ -12,6 +12,16 @@ Description: > cannot ensure that the data as exported to userland is > without error either. > > + 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. > + That's why SMBIOS entry point is represented in dmi sysfs > + like a raw attribute and is accessible via > + /sys/firmware/dmi/smbios_raw_header. The format of SMBIOS > + entry point header can be read in SMBIOS specification. > + > DMI is structured as a large table of entries, where > each entry has a common header indicating the type and > length of the entry, as well as a firmware-provided > diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysfs.c > index e0f1cb3..9b396d7 100644 > --- a/drivers/firmware/dmi-sysfs.c > +++ b/drivers/firmware/dmi-sysfs.c > @@ -29,6 +29,8 @@ > #define MAX_ENTRY_TYPE 255 /* Most of these aren't used, but we consider > the top entry type is only 8 bits */ > > +static const u8 *smbios_raw_header; > + > struct dmi_sysfs_entry { > struct dmi_header dh; > struct kobject kobj; > @@ -646,9 +648,37 @@ static void cleanup_entry_list(void) > } > } > > +static ssize_t smbios_entry_area_raw_read(struct file *filp, > + struct kobject *kobj, > + struct bin_attribute *bin_attr, > + char *buf, loff_t pos, size_t count) > +{ > + ssize_t size; > + > + size = bin_attr->size; > + > + if (size > pos) > + size -= pos; > + else > + return 0; > + > + if (count < size) > + size = count; > + > + memcpy(buf, &smbios_raw_header[pos], size); > + > + return size; > +} > + > +static struct bin_attribute smbios_raw_area_attr = { > + .read = smbios_entry_area_raw_read, > + .attr = {.name = "smbios_raw_header", .mode = 0400}, > +}; > + > static int __init dmi_sysfs_init(void) > { > int error = -ENOMEM; > + int size; > int val; > > /* Set up our directory */ > @@ -669,6 +699,18 @@ static int __init dmi_sysfs_init(void) > goto err; > } > > + smbios_raw_header = dmi_get_smbios_entry_area(&size); > + if (!smbios_raw_header) { > + pr_debug("dmi-sysfs: SMBIOS raw data is not available.\n"); > + error = -EINVAL; > + goto err; > + } > + > + /* Create the raw binary file to access the entry area */ > + smbios_raw_area_attr.size = size; > + if (sysfs_create_bin_file(dmi_kobj, &smbios_raw_area_attr)) > + goto err; > + > pr_debug("dmi-sysfs: loaded.\n"); > > return 0; > diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c > index 420c8d8..99c5f6c 100644 > --- a/drivers/firmware/dmi_scan.c > +++ b/drivers/firmware/dmi_scan.c > @@ -113,6 +113,8 @@ static void dmi_table(u8 *buf, int len, int num, > } > } > > +static u8 smbios_header[32]; > +static int smbios_header_size; > static phys_addr_t dmi_base; > static u16 dmi_len; > static u16 dmi_num; > @@ -474,6 +476,8 @@ 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_header_size = buf[5]; > + memcpy(smbios_header, buf, smbios_header_size); > > /* Some BIOS report weird SMBIOS version, fix that up */ > switch (smbios_ver) { > @@ -505,6 +509,8 @@ static int __init dmi_present(const u8 *buf) > pr_info("SMBIOS %d.%d present.\n", > dmi_ver >> 8, dmi_ver & 0xFF); > } else { > + smbios_header_size = 15; > + memcpy(smbios_header, buf, smbios_header_size); > dmi_ver = (buf[14] & 0xF0) << 4 | > (buf[14] & 0x0F); > pr_info("Legacy DMI %d.%d present.\n", > @@ -531,6 +537,8 @@ 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_header_size = buf[6]; > + memcpy(smbios_header, buf, smbios_header_size); > > /* > * The 64-bit SMBIOS 3.0 entry point no longer has a field > @@ -944,3 +952,21 @@ void dmi_memdev_name(u16 handle, const char **bank, const char **device) > } > } > EXPORT_SYMBOL_GPL(dmi_memdev_name); > + > +/** > + * dmi_get_smbios_entry_area - copy SMBIOS entry point area to array. > + * @size - pointer to assign actual size of SMBIOS entry point area. > + * > + * returns NULL if table is not available, otherwise returns pointer on > + * SMBIOS entry point area array. > + */ > +const u8 *dmi_get_smbios_entry_area(int *size) > +{ > + if (!smbios_header_size || !dmi_available) > + return NULL; > + > + *size = smbios_header_size; > + > + return smbios_header; > +} > +EXPORT_SYMBOL_GPL(dmi_get_smbios_entry_area); > diff --git a/include/linux/dmi.h b/include/linux/dmi.h > index f820f0a..8e1a28d 100644 > --- a/include/linux/dmi.h > +++ b/include/linux/dmi.h > @@ -109,6 +109,7 @@ extern int dmi_walk(void (*decode)(const struct dmi_header *, void *), > void *private_data); > extern bool dmi_match(enum dmi_field f, const char *str); > extern void dmi_memdev_name(u16 handle, const char **bank, const char **device); > +const u8 *dmi_get_smbios_entry_area(int *size); > > #else > > @@ -140,6 +141,8 @@ static inline void dmi_memdev_name(u16 handle, const char **bank, > const char **device) { } > static inline const struct dmi_system_id * > dmi_first_match(const struct dmi_system_id *list) { return NULL; } > +static inline const u8 *dmi_get_smbios_entry_area(int *size) > + { return NULL; } > > #endif > If you are Ok with this patch, could you please pickup it? 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