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e0ceeae708
The Hygon family 18h multi-die processor platform supports 1, 2 or
4-Dies per socket. The topology looks like this:
System View (with 1-Die 2-Socket):
|------------|
------ -----
SOCKET0 | D0 | | D1 | SOCKET1
------ -----
System View (with 2-Die 2-socket):
--------------------
| -------------|------
| | | |
------------ ------------
SOCKET0 | D1 -- D0 | | D3 -- D2 | SOCKET1
------------ ------------
System View (with 4-Die 2-Socket) :
--------------------
| -------------|------
| | | |
------------ ------------
| D1 -- D0 | | D7 -- D6 |
| | \/ | | | | \/ | |
SOCKET0 | | /\ | | | | /\ | | SOCKET1
| D2 -- D3 | | D4 -- D5 |
------------ ------------
| | | |
------|------------| |
--------------------
Currently
phys_proc_id = initial_apicid >> bits
calculates the physical processor ID from the initial_apicid by shifting
*bits*.
However, this does not work for 1-Die and 2-Die 2-socket systems.
According to document [1] section 2.1.11.1, the bits is the value of
CPUID_Fn80000008_ECX[12:15]. The possible values are 4, 5 or 6 which
mean:
4 - 1 die
5 - 2 dies
6 - 3/4 dies.
Hygon programs the initial ApicId the same way as AMD. The ApicId is
read from CPUID_Fn00000001_EBX (see section 2.1.11.1 of referrence [1])
and the definition is as below (see section 2.1.10.2.1.3 of [1]):
-------------------------------------------------
Bit | 6 | 5 4 | 3 | 2 1 0 |
|-----------|---------|--------|----------------|
IDs | Socket ID | Node ID | CCX ID | Core/Thread ID |
-------------------------------------------------
So for 3/4-Die configurations, the bits variable is 6, which is the same
as the ApicID definition field.
For 1-Die and 2-Die configurations, bits is 4 or 5, which will cause the
right shifted result to not be exactly the value of socket ID.
However, the socket ID should be obtained from ApicId[6]. To fix the
problem and match the ApicID field definition, set the shift bits to 6
for all Hygon family 18h multi-die CPUs.
Because AMD doesn't have 2-Socket systems with 1-Die/2-Die processors
(see reference [2]), this doesn't need to be changed on the AMD side but
only for Hygon.
References:
[1] https://www.amd.com/system/files/TechDocs/54945_PPR_Family_17h_Models_00h-0Fh.pdf
[2] https://www.amd.com/en/products/specifications/processors
[bp: heavily massage commit message. ]
Signed-off-by: Pu Wen <puwen@hygon.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Lendacky <Thomas.Lendacky@amd.com>
Cc: Yazen Ghannam <yazen.ghannam@amd.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/1553355740-19999-1-git-send-email-puwen@hygon.cn
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.