<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/edac/amd64_edac.c, branch v6.11</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>EDAC/amd64: Check return value of amd_smn_read()</title>
<updated>2024-06-12T09:33:45+00:00</updated>
<author>
<name>Yazen Ghannam</name>
<email>yazen.ghannam@amd.com</email>
</author>
<published>2024-06-06T16:12:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5ac6293047cf5de6daca662347c19347e856c2a5'/>
<id>5ac6293047cf5de6daca662347c19347e856c2a5</id>
<content type='text'>
Check the return value of amd_smn_read() before saving a value. This
ensures invalid values aren't saved. The struct umc instance is
initialized to 0 during memory allocation. Therefore, a bad read will
keep the value as 0 providing the expected Read-as-Zero behavior.

Signed-off-by: Yazen Ghannam &lt;yazen.ghannam@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Link: https://lore.kernel.org/r/20240606-fix-smn-bad-read-v4-2-ffde21931c3f@amd.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Check the return value of amd_smn_read() before saving a value. This
ensures invalid values aren't saved. The struct umc instance is
initialized to 0 during memory allocation. Therefore, a bad read will
keep the value as 0 providing the expected Read-as-Zero behavior.

Signed-off-by: Yazen Ghannam &lt;yazen.ghannam@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Link: https://lore.kernel.org/r/20240606-fix-smn-bad-read-v4-2-ffde21931c3f@amd.com
</pre>
</div>
</content>
</entry>
<entry>
<title>EDAC/amd64: Remove unused register accesses</title>
<updated>2024-06-12T09:33:45+00:00</updated>
<author>
<name>Yazen Ghannam</name>
<email>yazen.ghannam@amd.com</email>
</author>
<published>2024-06-06T16:12:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f97a8b9170a0524c5432791cd5852bf797934af4'/>
<id>f97a8b9170a0524c5432791cd5852bf797934af4</id>
<content type='text'>
A number of UMC registers are read only for the purpose of debug printing. They
are not used in any calculations. Nor do they have any specific debug value.

Remove them.

Signed-off-by: Yazen Ghannam &lt;yazen.ghannam@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Link: https://lore.kernel.org/r/20240606-fix-smn-bad-read-v4-1-ffde21931c3f@amd.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A number of UMC registers are read only for the purpose of debug printing. They
are not used in any calculations. Nor do they have any specific debug value.

Remove them.

Signed-off-by: Yazen Ghannam &lt;yazen.ghannam@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Link: https://lore.kernel.org/r/20240606-fix-smn-bad-read-v4-1-ffde21931c3f@amd.com
</pre>
</div>
</content>
</entry>
<entry>
<title>EDAC/amd64: Convert PCIBIOS_* return codes to errnos</title>
<updated>2024-06-04T09:24:16+00:00</updated>
<author>
<name>Ilpo Järvinen</name>
<email>ilpo.jarvinen@linux.intel.com</email>
</author>
<published>2024-05-27T13:22:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3ec8ebd8a5b782d56347ae884de880af26f93996'/>
<id>3ec8ebd8a5b782d56347ae884de880af26f93996</id>
<content type='text'>
gpu_get_node_map() uses pci_read_config_dword() that returns PCIBIOS_*
codes. The return code is then returned all the way into the module
init function amd64_edac_init() that returns it as is. The module init
functions, however, should return normal errnos.

Convert PCIBIOS_* returns code using pcibios_err_to_errno() into normal
errno before returning it from gpu_get_node_map().

For consistency, convert also the other similar cases which return
PCIBIOS_* codes even if they do not have any bugs at the moment.

Fixes: 4251566ebc1c ("EDAC/amd64: Cache and use GPU node map")
Signed-off-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240527132236.13875-1-ilpo.jarvinen@linux.intel.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
gpu_get_node_map() uses pci_read_config_dword() that returns PCIBIOS_*
codes. The return code is then returned all the way into the module
init function amd64_edac_init() that returns it as is. The module init
functions, however, should return normal errnos.

Convert PCIBIOS_* returns code using pcibios_err_to_errno() into normal
errno before returning it from gpu_get_node_map().

For consistency, convert also the other similar cases which return
PCIBIOS_* codes even if they do not have any bugs at the moment.

Fixes: 4251566ebc1c ("EDAC/amd64: Cache and use GPU node map")
Signed-off-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240527132236.13875-1-ilpo.jarvinen@linux.intel.com
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'edac_updates_for_v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras</title>
<updated>2024-03-12T01:14:06+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-03-12T01:14:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b0402403e54ae9eb94ce1cbb53c7def776e97426'/>
<id>b0402403e54ae9eb94ce1cbb53c7def776e97426</id>
<content type='text'>
Pull EDAC updates from Borislav Petkov:

 - Add a FRU (Field Replaceable Unit) memory poison manager which
   collects and manages previously encountered hw errors in order to
   save them to persistent storage across reboots. Previously recorded
   errors are "replayed" upon reboot in order to poison memory which has
   caused said errors in the past.

   The main use case is stacked, on-chip memory which cannot simply be
   replaced so poisoning faulty areas of it and thus making them
   inaccessible is the only strategy to prolong its lifetime.

 - Add an AMD address translation library glue which converts the
   reported addresses of hw errors into system physical addresses in
   order to be used by other subsystems like memory failure, for
   example. Add support for MI300 accelerators to that library.

 - igen6: Add support for Alder Lake-N SoC

 - i10nm: Add Grand Ridge support

 - The usual fixlets and cleanups

* tag 'edac_updates_for_v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
  EDAC/versal: Convert to platform remove callback returning void
  RAS/AMD/FMPM: Fix off by one when unwinding on error
  RAS/AMD/FMPM: Add debugfs interface to print record entries
  RAS/AMD/FMPM: Save SPA values
  RAS: Export helper to get ras_debugfs_dir
  RAS/AMD/ATL: Fix bit overflow in denorm_addr_df4_np2()
  RAS: Introduce a FRU memory poison manager
  RAS/AMD/ATL: Add MI300 row retirement support
  Documentation: Move RAS section to admin-guide
  EDAC/versal: Make the bit position of injected errors configurable
  EDAC/i10nm: Add Intel Grand Ridge micro-server support
  EDAC/igen6: Add one more Intel Alder Lake-N SoC support
  RAS/AMD/ATL: Add MI300 DRAM to normalized address translation support
  RAS/AMD/ATL: Fix array overflow in get_logical_coh_st_fabric_id_mi300()
  RAS/AMD/ATL: Add MI300 support
  Documentation: RAS: Add index and address translation section
  EDAC/amd64: Use new AMD Address Translation Library
  RAS: Introduce AMD Address Translation Library
  EDAC/synopsys: Convert to devm_platform_ioremap_resource()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull EDAC updates from Borislav Petkov:

 - Add a FRU (Field Replaceable Unit) memory poison manager which
   collects and manages previously encountered hw errors in order to
   save them to persistent storage across reboots. Previously recorded
   errors are "replayed" upon reboot in order to poison memory which has
   caused said errors in the past.

   The main use case is stacked, on-chip memory which cannot simply be
   replaced so poisoning faulty areas of it and thus making them
   inaccessible is the only strategy to prolong its lifetime.

 - Add an AMD address translation library glue which converts the
   reported addresses of hw errors into system physical addresses in
   order to be used by other subsystems like memory failure, for
   example. Add support for MI300 accelerators to that library.

 - igen6: Add support for Alder Lake-N SoC

 - i10nm: Add Grand Ridge support

 - The usual fixlets and cleanups

* tag 'edac_updates_for_v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
  EDAC/versal: Convert to platform remove callback returning void
  RAS/AMD/FMPM: Fix off by one when unwinding on error
  RAS/AMD/FMPM: Add debugfs interface to print record entries
  RAS/AMD/FMPM: Save SPA values
  RAS: Export helper to get ras_debugfs_dir
  RAS/AMD/ATL: Fix bit overflow in denorm_addr_df4_np2()
  RAS: Introduce a FRU memory poison manager
  RAS/AMD/ATL: Add MI300 row retirement support
  Documentation: Move RAS section to admin-guide
  EDAC/versal: Make the bit position of injected errors configurable
  EDAC/i10nm: Add Intel Grand Ridge micro-server support
  EDAC/igen6: Add one more Intel Alder Lake-N SoC support
  RAS/AMD/ATL: Add MI300 DRAM to normalized address translation support
  RAS/AMD/ATL: Fix array overflow in get_logical_coh_st_fabric_id_mi300()
  RAS/AMD/ATL: Add MI300 support
  Documentation: RAS: Add index and address translation section
  EDAC/amd64: Use new AMD Address Translation Library
  RAS: Introduce AMD Address Translation Library
  EDAC/synopsys: Convert to devm_platform_ioremap_resource()
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/cpu/amd: Provide a separate accessor for Node ID</title>
<updated>2024-02-15T21:07:37+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2024-02-13T21:04:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7e3ec6286753b404666af9a58d283690302c9321'/>
<id>7e3ec6286753b404666af9a58d283690302c9321</id>
<content type='text'>
AMD (ab)uses topology_die_id() to store the Node ID information and
topology_max_dies_per_pkg to store the number of nodes per package.

This collides with the proper processor die level enumeration which is
coming on AMD with CPUID 8000_0026, unless there is a correlation between
the two. There is zero documentation about that.

So provide new storage and new accessors which for now still access die_id
and topology_max_die_per_pkg(). Will be mopped up after AMD and HYGON are
converted over.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Tested-by: Juergen Gross &lt;jgross@suse.com&gt;
Tested-by: Sohil Mehta &lt;sohil.mehta@intel.com&gt;
Tested-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Tested-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
Tested-by: Wang Wendy &lt;wendy.wang@intel.com&gt;
Tested-by: K Prateek Nayak &lt;kprateek.nayak@amd.com&gt;
Link: https://lore.kernel.org/r/20240212153624.956116738@linutronix.de

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
AMD (ab)uses topology_die_id() to store the Node ID information and
topology_max_dies_per_pkg to store the number of nodes per package.

This collides with the proper processor die level enumeration which is
coming on AMD with CPUID 8000_0026, unless there is a correlation between
the two. There is zero documentation about that.

So provide new storage and new accessors which for now still access die_id
and topology_max_die_per_pkg(). Will be mopped up after AMD and HYGON are
converted over.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Tested-by: Juergen Gross &lt;jgross@suse.com&gt;
Tested-by: Sohil Mehta &lt;sohil.mehta@intel.com&gt;
Tested-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Tested-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
Tested-by: Wang Wendy &lt;wendy.wang@intel.com&gt;
Tested-by: K Prateek Nayak &lt;kprateek.nayak@amd.com&gt;
Link: https://lore.kernel.org/r/20240212153624.956116738@linutronix.de

</pre>
</div>
</content>
</entry>
<entry>
<title>EDAC/amd64: Use new AMD Address Translation Library</title>
<updated>2024-01-24T11:55:00+00:00</updated>
<author>
<name>Yazen Ghannam</name>
<email>yazen.ghannam@amd.com</email>
</author>
<published>2024-01-23T04:14:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6c9058f49084569d1d816e87185e0a4f9ab1a321'/>
<id>6c9058f49084569d1d816e87185e0a4f9ab1a321</id>
<content type='text'>
Remove old address translation code and use the new AMD Address
Translation Library.

Use "imply" in Kconfig so that the "AMD_ATL" config option takes the
value of "EDAC_AMD64" as its default.

Signed-off-by: Yazen Ghannam &lt;yazen.ghannam@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20240123041401.79812-3-yazen.ghannam@amd.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove old address translation code and use the new AMD Address
Translation Library.

Use "imply" in Kconfig so that the "AMD_ATL" config option takes the
value of "EDAC_AMD64" as its default.

Signed-off-by: Yazen Ghannam &lt;yazen.ghannam@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20240123041401.79812-3-yazen.ghannam@amd.com
</pre>
</div>
</content>
</entry>
<entry>
<title>EDAC/amd64: Add support for family 0x19, models 0x90-9f devices</title>
<updated>2023-11-29T10:21:05+00:00</updated>
<author>
<name>Muralidhara M K</name>
<email>muralidhara.mk@amd.com</email>
</author>
<published>2023-11-02T11:42:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=12f230c07a95d925d6af754485952515e7975127'/>
<id>12f230c07a95d925d6af754485952515e7975127</id>
<content type='text'>
AMD Models 90h-9fh are APUs. They have built-in HBM3 memory. ECC support
is enabled by default.

APU models have a single Data Fabric (DF) per Package. Each DF is
visible to the OS in the same way as chiplet-based systems like Zen2
CPUs and later. However, the Unified Memory Controllers (UMCs) are
arranged in the same way as GPU-based MI200 devices rather than
CPU-based systems.

Use the existing gpu_ops for hetergeneous systems to support enumeration
of nodes and memory topology with few fixups.

  [ bp: Massage comments. ]

Signed-off-by: Muralidhara M K &lt;muralidhara.mk@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20231102114225.2006878-5-muralimk@amd.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
AMD Models 90h-9fh are APUs. They have built-in HBM3 memory. ECC support
is enabled by default.

APU models have a single Data Fabric (DF) per Package. Each DF is
visible to the OS in the same way as chiplet-based systems like Zen2
CPUs and later. However, the Unified Memory Controllers (UMCs) are
arranged in the same way as GPU-based MI200 devices rather than
CPU-based systems.

Use the existing gpu_ops for hetergeneous systems to support enumeration
of nodes and memory topology with few fixups.

  [ bp: Massage comments. ]

Signed-off-by: Muralidhara M K &lt;muralidhara.mk@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20231102114225.2006878-5-muralimk@amd.com
</pre>
</div>
</content>
</entry>
<entry>
<title>EDAC/amd64: Add support for AMD family 1Ah models 00h-1Fh and 40h-4Fh</title>
<updated>2023-08-10T12:25:21+00:00</updated>
<author>
<name>Avadhut Naik</name>
<email>Avadhut.Naik@amd.com</email>
</author>
<published>2023-08-09T03:52:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c4d07c371283cb0453c8ce187551e4d064cc407e'/>
<id>c4d07c371283cb0453c8ce187551e4d064cc407e</id>
<content type='text'>
Add support for family 1Ah-based models 00h-1Fh and 40h-4Fh.

  [ bp: Simplify. ]

Signed-off-by: Avadhut Naik &lt;Avadhut.Naik@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20230809035244.2722455-4-avadhut.naik@amd.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add support for family 1Ah-based models 00h-1Fh and 40h-4Fh.

  [ bp: Simplify. ]

Signed-off-by: Avadhut Naik &lt;Avadhut.Naik@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20230809035244.2722455-4-avadhut.naik@amd.com
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'ras_core_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2023-06-26T22:09:18+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-06-26T22:09:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=aa35a4835e4f4c113c29bc7ea64cfecb951d51b8'/>
<id>aa35a4835e4f4c113c29bc7ea64cfecb951d51b8</id>
<content type='text'>
Pull RAS updates from Borislav Petkov:

 - Add initial support for RAS hardware found on AMD server GPUs (MI200).

   Those GPUs and CPUs are connected together through the coherent
   fabric and the GPU memory controllers report errors through x86's MCA
   so EDAC needs to support them. The amd64_edac driver supports now HBM
   (High Bandwidth Memory) and thus such heterogeneous memory controller
   systems

 - Other small cleanups and improvements

* tag 'ras_core_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  EDAC/amd64: Cache and use GPU node map
  EDAC/amd64: Add support for AMD heterogeneous Family 19h Model 30h-3Fh
  EDAC/amd64: Document heterogeneous system enumeration
  x86/MCE/AMD, EDAC/mce_amd: Decode UMC_V2 ECC errors
  x86/amd_nb: Re-sort and re-indent PCI defines
  x86/amd_nb: Add MI200 PCI IDs
  ras/debugfs: Fix error checking for debugfs_create_dir()
  x86/MCE: Check a hw error's address to determine proper recovery action
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull RAS updates from Borislav Petkov:

 - Add initial support for RAS hardware found on AMD server GPUs (MI200).

   Those GPUs and CPUs are connected together through the coherent
   fabric and the GPU memory controllers report errors through x86's MCA
   so EDAC needs to support them. The amd64_edac driver supports now HBM
   (High Bandwidth Memory) and thus such heterogeneous memory controller
   systems

 - Other small cleanups and improvements

* tag 'ras_core_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  EDAC/amd64: Cache and use GPU node map
  EDAC/amd64: Add support for AMD heterogeneous Family 19h Model 30h-3Fh
  EDAC/amd64: Document heterogeneous system enumeration
  x86/MCE/AMD, EDAC/mce_amd: Decode UMC_V2 ECC errors
  x86/amd_nb: Re-sort and re-indent PCI defines
  x86/amd_nb: Add MI200 PCI IDs
  ras/debugfs: Fix error checking for debugfs_create_dir()
  x86/MCE: Check a hw error's address to determine proper recovery action
</pre>
</div>
</content>
</entry>
<entry>
<title>EDAC/amd64: Cache and use GPU node map</title>
<updated>2023-06-19T11:01:44+00:00</updated>
<author>
<name>Yazen Ghannam</name>
<email>yazen.ghannam@amd.com</email>
</author>
<published>2023-05-15T11:35:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4251566ebc1cf95ae26a1e5a24cdac1ac25e942f'/>
<id>4251566ebc1cf95ae26a1e5a24cdac1ac25e942f</id>
<content type='text'>
AMD systems have historically provided an "AMD Node ID" that is a unique
identifier for each die in a multi-die package. This was associated with
a unique instance of the AMD Northbridge on a legacy system. And now it
is associated with a unique instance of the AMD Data Fabric on modern
systems. Each instance is referred to as a "Node"; this is an
AMD-specific term not to be confused with NUMA nodes.

The data fabric provides a number of interfaces accessible through a set
of functions in a single PCI device. There is one PCI device per Data
Fabric (AMD Node), and multi-die systems will see multiple such PCI
devices. The AMD Node ID matches a Node's position in the PCI hierarchy.
For example, the Node 0 is accessed using the first PCI device, Node 1
is accessed using the second, and so on. A logical CPU can find its AMD
Node ID using CPUID. Furthermore, the AMD Node ID is used within the
hardware fabric, so it is not purely a logical value.

Heterogeneous AMD systems, with a CPU Data Fabric connected to GPU data
fabrics, follow a similar convention. Each CPU and GPU die has a unique
AMD Node ID value, and each Node ID corresponds to PCI devices in
sequential order.

However, there are two caveats:
1) GPUs are not x86, and they don't have CPUID to read their AMD Node ID
like on CPUs. This means the value is more implicit and based on PCI
enumeration and hardware-specifics.
2) There is a gap in the hardware values for AMD Node IDs. Values 0-7
are for CPUs and values 8-15 are for GPUs.

For example, a system with one CPU die and two GPUs dies will have the
following values:
  CPU0 -&gt; AMD Node 0
  GPU0 -&gt; AMD Node 8
  GPU1 -&gt; AMD Node 9

EDAC is the only subsystem where this has a practical effect. Memory
errors on AMD systems are commonly reported through MCA to a CPU on the
local AMD Node. The error information is passed along to EDAC where the
AMD EDAC modules use the AMD Node ID of reporting logical CPU to access
AMD Node information.

However, memory errors from a GPU die will be reported to the CPU die.
Therefore, the logical CPU's AMD Node ID can't be used since it won't
match the AMD Node ID of the GPU die. The AMD Node ID of the GPU die is
provided as part of the MCA information, and the value will match the
hardware enumeration (e.g. 8-15).

Handle this situation by discovering GPU dies the same way as CPU dies
in the AMD NB code. But do a "node id" fixup in AMD64 EDAC where it's
needed.

The GPU data fabrics provide a register with the base AMD Node ID for
their local "type", i.e. GPU data fabric. This value is the same for all
fabrics of the same type in a system.

Read and cache the base AMD Node ID from one of the GPU devices during
module initialization. Use this to fixup the "node id" when reporting
memory errors at runtime.

  [ bp: Squash a fix making gpu_node_map static as reported by
        Tom Rix &lt;trix@redhat.com&gt;.
    Link: https://lore.kernel.org/r/20230610210930.174074-1-trix@redhat.com ]

Signed-off-by: Yazen Ghannam &lt;yazen.ghannam@amd.com&gt;
Co-developed-by: Muralidhara M K &lt;muralidhara.mk@amd.com&gt;
Signed-off-by: Muralidhara M K &lt;muralidhara.mk@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20230515113537.1052146-6-muralimk@amd.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
AMD systems have historically provided an "AMD Node ID" that is a unique
identifier for each die in a multi-die package. This was associated with
a unique instance of the AMD Northbridge on a legacy system. And now it
is associated with a unique instance of the AMD Data Fabric on modern
systems. Each instance is referred to as a "Node"; this is an
AMD-specific term not to be confused with NUMA nodes.

The data fabric provides a number of interfaces accessible through a set
of functions in a single PCI device. There is one PCI device per Data
Fabric (AMD Node), and multi-die systems will see multiple such PCI
devices. The AMD Node ID matches a Node's position in the PCI hierarchy.
For example, the Node 0 is accessed using the first PCI device, Node 1
is accessed using the second, and so on. A logical CPU can find its AMD
Node ID using CPUID. Furthermore, the AMD Node ID is used within the
hardware fabric, so it is not purely a logical value.

Heterogeneous AMD systems, with a CPU Data Fabric connected to GPU data
fabrics, follow a similar convention. Each CPU and GPU die has a unique
AMD Node ID value, and each Node ID corresponds to PCI devices in
sequential order.

However, there are two caveats:
1) GPUs are not x86, and they don't have CPUID to read their AMD Node ID
like on CPUs. This means the value is more implicit and based on PCI
enumeration and hardware-specifics.
2) There is a gap in the hardware values for AMD Node IDs. Values 0-7
are for CPUs and values 8-15 are for GPUs.

For example, a system with one CPU die and two GPUs dies will have the
following values:
  CPU0 -&gt; AMD Node 0
  GPU0 -&gt; AMD Node 8
  GPU1 -&gt; AMD Node 9

EDAC is the only subsystem where this has a practical effect. Memory
errors on AMD systems are commonly reported through MCA to a CPU on the
local AMD Node. The error information is passed along to EDAC where the
AMD EDAC modules use the AMD Node ID of reporting logical CPU to access
AMD Node information.

However, memory errors from a GPU die will be reported to the CPU die.
Therefore, the logical CPU's AMD Node ID can't be used since it won't
match the AMD Node ID of the GPU die. The AMD Node ID of the GPU die is
provided as part of the MCA information, and the value will match the
hardware enumeration (e.g. 8-15).

Handle this situation by discovering GPU dies the same way as CPU dies
in the AMD NB code. But do a "node id" fixup in AMD64 EDAC where it's
needed.

The GPU data fabrics provide a register with the base AMD Node ID for
their local "type", i.e. GPU data fabric. This value is the same for all
fabrics of the same type in a system.

Read and cache the base AMD Node ID from one of the GPU devices during
module initialization. Use this to fixup the "node id" when reporting
memory errors at runtime.

  [ bp: Squash a fix making gpu_node_map static as reported by
        Tom Rix &lt;trix@redhat.com&gt;.
    Link: https://lore.kernel.org/r/20230610210930.174074-1-trix@redhat.com ]

Signed-off-by: Yazen Ghannam &lt;yazen.ghannam@amd.com&gt;
Co-developed-by: Muralidhara M K &lt;muralidhara.mk@amd.com&gt;
Signed-off-by: Muralidhara M K &lt;muralidhara.mk@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20230515113537.1052146-6-muralimk@amd.com
</pre>
</div>
</content>
</entry>
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