Memory errors are an expected occurrence on systems with high memory
density. Generally, errors within a small number of unique physical
locations are acceptable, based on manufacturer and/or admin policy.
During run time, memory with errors may be retired so it is no longer
used by the system. This is done in mm through page poisoning, and the
effect will remain until the system is restarted.
If a memory location is consistently faulty, then the same run time
error handling may occur in the next reboot cycle, leading to
terminating jobs due to that already known bad memory. This could be
prevented if information from the previous boot was not lost.
Some add-in cards with driver-managed memory have on-board persistent
storage. Their driver saves memory error information to the persistent
storage during run time. The information is then restored after reset,
and known bad memory will be retired before the hardware is used.
A running log of bad memory locations is kept across multiple resets.
A similar solution is desirable for CPUs. However, this solution should
leverage industry-standard components as much as possible, rather than
a bespoke platform driver.
Two components are needed: a record format and a persistent storage
interface.
Implement a new module to manage the record formats on persistent
storage. Use the requirements for an AMD MI300-based system to start.
Vendor- and platform-specific details can be abstracted later as needed.
[ bp: Massage commit message and code, squash 30-ish more fixes from
Yazen and me. ]
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Co-developed-by: <naveenkrishna.chatradhi@amd.com>
Signed-off-by: <naveenkrishna.chatradhi@amd.com>
Co-developed-by: <muralidhara.mk@amd.com>
Signed-off-by: <muralidhara.mk@amd.com>
Tested-by: <sathyapriya.k@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240214033516.1344948-3-yazen.ghannam@amd.com
AMD Zen-based systems report memory errors through Machine Check banks
representing Unified Memory Controllers (UMCs). The address value
reported for DRAM ECC errors is a "normalized address" that is relative
to the UMC. This normalized address must be converted to a system
physical address to be usable by the OS.
Support for this address translation was introduced to the MCA subsystem
with Zen1 systems. The code was later moved to the AMD64 EDAC module,
since this was the only user of the code at the time.
However, there are uses for this translation outside of EDAC. The system
physical address can be used in MCA for preemptive page offlining as done
in some MCA notifier functions. Also, this translation is needed as the
basis of similar functionality needed for some CXL configurations on AMD
systems.
Introduce a common address translation library that can be used for
multiple subsystems including MCA, EDAC, and CXL.
Include support for UMC normalized to system physical address
translation for current CPU systems.
The Data Fabric Indirect register access offsets and one of the register
fields were changed. Default to the current offsets and register field
definition. And fallback to the older values if running on a "legacy"
system.
Provide built-in code to facilitate the loading and unloading of the
library module without affecting other modules or built-in code.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240123041401.79812-2-yazen.ghannam@amd.com
In addition, the 0day bot reported this build error:
>> drivers/ras/debugfs.c:10:5: error: redefinition of 'ras_userspace_consumers'
int ras_userspace_consumers(void)
^~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/ras/debugfs.c:3:0:
include/linux/ras.h:14:19: note: previous definition of 'ras_userspace_consumers' was here
static inline int ras_userspace_consumers(void) { return 0; }
^~~~~~~~~~~~~~~~~~~~~~~
for a riscv-specific .config where CONFIG_DEBUG_FS is not set. Fix all
that by making debugfs.o depend on that define.
[ bp: Rewrite commit message. ]
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac@vger.kernel.org
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/7053.1565218556@turing-police
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce a simple data structure for collecting correctable errors
along with accessors. More detailed description in the code itself.
The error decoding is done with the decoding chain now and
mce_first_notifier() gets to see the error first and the CEC decides
whether to log it and then the rest of the chain doesn't hear about it -
basically the main reason for the CE collector - or to continue running
the notifiers.
When the CEC hits the action threshold, it will try to soft-offine the
page containing the ECC and then the whole decoding chain gets to see
the error.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20170327093304.10683-5-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Implement a new debugfs interface for RAS susbsystem.
A file named daemon_active is added there accordingly.
This file is used to track if user space daemon accesses
perf/trace interface or not. One can track which daemon
opens it via "lsof /path/to/debugfs/ras/daemon_active".
Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/1402475691-30045-5-git-send-email-gong.chen@linux.intel.com
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
To avoid confuision and conflict of usage for RAS related trace event,
add an unified RAS trace event stub.
Start a RAS subsystem menu which will be fleshed out in time, when more
features get added to it.
Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/1402475691-30045-2-git-send-email-gong.chen@linux.intel.com
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
