On Mon, Jun 14, 2021 at 12:41:26PM +0200, Karel Zak wrote:
>
> CC: Masayoshi and Jeffrey,
>
> On Mon, Jun 14, 2021 at 09:48:45AM +0000, Huang Shijie wrote:
> > The patch :367c85c47286 ("lscpu: use SMBIOS tables on ARM for lscpu")
> > relies on the existence of "/sys/firmware/dmi/entries/4-0/raw",
> > which may not exist in standard linux kernel.
> >
> > But "/sys/firmware/dmi/tables/DMI" should exist and can provide the required
> > processor information.
>
> Good idea to add a fallback solution.
>
> > This patch uses "/sys/firmware/dmi/tables/DMI"
> > to get the processor information:
> > 1.) Use the DMI to provide more accurate "Model name" information.
>
> We've had a long discussion about data from DMI and we had a few
> attempts to implement it ;-) The conclusion is to differentiate
> between information decoded from IDs and information from BIOS, so now
> we have two fields ct->bios_modelname and ct->modelname (and
> ct->bios_vendor).
Okay.
I will the ct->bios_modelname/ct->modelname /ct->bios_vendor in next version.
>
> The reason is that in some cases the strings from DMI do not provide
> well-known CPU names and info by user.
>
> Vendor ID: ARM
> BIOS Vendor ID: https://www.mellanox.com
> Model: 0
> Model name: Cortex-A72
> BIOS Model name: Mellanox BlueField-2 [A0] A72(D08) r1p0
>
> "Cortex-A72" is pretty well-known, Mellanox BlueField is some
> marketing name, another example:
>
> Vendor ID: Cavium
> BIOS Vendor ID: CN8890-2000BG2601-AAP-PR-Y-G
> Model: 0
> Model name: ThunderX 88XX
> BIOS Model name: 2.0
>
> > After this patch, we can get the lscpu output
> > in Ampere Altra platform:
> > ---------------------------------------------
> > Architecture: aarch64
> > CPU op-mode(s): 32-bit, 64-bit
> > Byte Order: Little Endian
> > CPU(s): 160
> > On-line CPU(s) list: 0-159
> > Vendor ID: ARM
> > Model name: Ampere(R) Altra(R) Processor Q00-00 CPU @ 3.0GHz
>
> Should be
>
> Model name: Neoverse-N1
okay..
> BIOS Model name: Ampere(R) Altra(R) Processor Q00-00 CPU @ 3.0GHz
>
> > static void arm_decode(struct lscpu_cxt *cxt, struct lscpu_cputype *ct)
> > {
> > + /* dmi_decode_cputype may get more accurate information later */
> > + arm_ids_decode(ct);
> > +
> > /* use SMBIOS Type 4 data if available */
> > if (!cxt->noalive && access(_PATH_SYS_DMI_TYPE4, R_OK) == 0)
> > arm_smbios_decode(ct);
> > + else if (!cxt->noalive && access(_PATH_SYS_DMI, R_OK) == 0)
> > + dmi_decode_cputype(ct);
> >
> > - arm_ids_decode(ct);
>
> Please, do not move arm_ids_decode().
no problem.
>
> > +int dmi_decode_cputype(struct lscpu_cputype *ct)
> > +{
> > + static char const sys_fw_dmi_tables[] = _PATH_SYS_DMI;
> > + struct dmi_info di = { };
> > + struct stat st;
> > + uint8_t *data;
> > + int rc = 0;
> > + char buf[100] = { };
> > +
> > + if (stat(sys_fw_dmi_tables, &st))
> > + return rc;
> > +
> > + data = get_mem_chunk(0, st.st_size, sys_fw_dmi_tables);
> > + if (!data)
> > + return rc;
> > +
> > + rc = parse_dmi_table(st.st_size, st.st_size/4, data, &di);
> > + if (rc < 0) {
> > + free(data);
> > + return rc;
> > + }
> > +
> > + /* Get module name */
> > + sprintf(buf, "%s %s CPU @ %d.%dGHz", di.processor_version, di.part_num,
> > + di.current_speed/1000, (di.current_speed % 1000) / 100);
>
> So, it's not string from DMI, but it's composed from more information
> and it seems compatible to "model name:" from (x86) /proc/cpuinfo. I'm
> fine with it.
Thanks.
>
> > + free(ct->modelname);
> > + ct->modelname = xstrdup(buf);
>
> Please:
>
> ct->bios_modelname = xstrdup(buf);
okay.
>
>
> > + /* Get CPU family */
> > + memset(buf, 0, sizeof(buf));
> > + sprintf(buf, "%d", di.processor_family);
> > + free(ct->family);
> > + ct->family = xstrdup(buf);
>
> is there any difference between "cpu family" from /proc/cpuinfo and
> this DMI field? Do we need a new field ct->bios_family or overwrite
> the ct->family good enough? I don't know ;-)
>
In the arm platform, it seems it does not show the "cpu family" info in lscpu.
And I did not find the "cpu family" in the /proc/cpuinfo, only find "cpu architecture: 8".
Unfortunately, the "cpu architecture :8 " is hardcode, it will be changed for armv9 in future.
In the DMI, the "cpu family" shows 0x101 which means "arm v8".
Thanks
Huang Shijie
