linux-stable.git/drivers/ras, branch v6.9

RAS: Avoid build errors when CONFIG_DEBUG_FS=n

2024-03-26T20:48:21+00:00

A new helper was introduced for RAS modules to be able to get the RAS
subsystem debugfs root directory. The helper is defined in debugfs.c
which is only built when CONFIG_DEBUG_FS=y.

However, it's possible that the modules would include debugfs support
for optional functionality. One current example is the fmpm module. In
this case, a build error will occur when CONFIG_RAS_FMPM is selected and
CONFIG_DEBUG_FS=n.

Add an inline helper function stub for the CONFIG_DEBUG_FS=n case as the
fmpm module can function without the debugfs functionality too.

Fixes: 9d2b6fa09d15 ("RAS: Export helper to get ras_debugfs_dir")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218640
Reported-by: anthony s. knowles 
Signed-off-by: Yazen Ghannam 
Signed-off-by: Borislav Petkov (AMD) 
Tested-by: anthony s. knowles 
Link: https://lore.kernel.org/r/20240325183755.776-1-bp@alien8.de

RAS/AMD/FMPM: Safely handle saved records of various sizes

2024-03-25T18:00:44+00:00

Currently, the size of the locally cached FRU record structures is
based on the module parameter "max_nr_entries".

This creates issues when restoring records if a user changes the
parameter.

If the number of entries is reduced, then old, larger records will not
be restored. The opportunity to take action on the saved data is missed.
Also, new records will be created and written to storage, even as the old
records remain in storage, resulting in wasted space.

If the number of entries is increased, then the length of the old,
smaller records will not be adjusted. This causes a checksum failure
which leads to the old record being cleared from storage. Again this
results in another missed opportunity for action on the saved data.

Allocate the temporary record with the maximum possible size based on
the current maximum number of supported entries (255). This allows the
ERST read operation to succeed if max_nr_entries has been increased.

Warn the user if a saved record exceeds the expected size and fail to
load the module. This allows the user to adjust the module parameter
without losing data or the opportunity to restore larger records.

Increase the size of a saved record up to the current max_rec_len. The
checksum will be recalculated, and the updated record will be written to
storage.

Fixes: 6f15e617cc99 ("RAS: Introduce a FRU memory poison manager")
Signed-off-by: Yazen Ghannam 
Signed-off-by: Borislav Petkov (AMD) 
Tested-by: Muralidhara M K 
Link: https://lore.kernel.org/r/20240319113322.280096-3-yazen.ghannam@amd.com

RAS/AMD/FMPM: Avoid NULL ptr deref in get_saved_records()

2024-03-25T18:00:38+00:00

An old, invalid record should be cleared and skipped.

Currently, the record is cleared in ERST, but it is not skipped. This
leads to a NULL pointer dereference when attempting to copy the old
record to the new record.

Continue the loop after clearing an old, invalid record to skip it.

Fixes: 6f15e617cc99 ("RAS: Introduce a FRU memory poison manager")
Signed-off-by: Yazen Ghannam 
Signed-off-by: Borislav Petkov (AMD) 
Tested-by: Muralidhara M K 
Link: https://lore.kernel.org/r/20240319113322.280096-2-yazen.ghannam@amd.com

Merge tag 'edac_updates_for_v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras

2024-03-12T01:14:06+00:00

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()

RAS/AMD/FMPM: Fix off by one when unwinding on error

2024-03-06T09:22:19+00:00

Decrement the index variable i before the first iteration when freeing
the remaining elements on error. Depending on where this fails it could
free something from one element beyond the end of the fru_records[]
array.

  [ bp: Massage commit message. ]

Fixes: 6f15e617cc99 ("RAS: Introduce a FRU memory poison manager")
Signed-off-by: Dan Carpenter 
Signed-off-by: Borislav Petkov (AMD) 
Link: https://lore.kernel.org/r/6fdec71a-846b-4cd0-af69-e5f6cd12f4f6@moroto.mountain

RAS/AMD/FMPM: Add debugfs interface to print record entries

2024-03-01T15:55:24+00:00

It is helpful to see the saved record entries during run time in
human-readable format. This is useful for testing during module
development. It can also be used by system admins to quickly and easily
see the state of the system.

Provide a sequential file in debugfs to print fields of interest from
the FRU records and their entries.

Don't fail to load the module if the debugfs interface is not available.
This is a convenience feature which does not affect other module
functionality.

The new interface reads the record entries and should hold the mutex.
Expand the mutex code comment to clarify when it should be held.

Signed-off-by: Yazen Ghannam 
Signed-off-by: Borislav Petkov (AMD) 
Link: https://lore.kernel.org/r/20240301143748.854090-4-yazen.ghannam@amd.com

RAS/AMD/FMPM: Save SPA values

2024-03-01T15:55:18+00:00

The system physical address (SPA) of an error is not a stable value. It
will change depending on the location of the memory: parts can be
swapped. And it will change depending on memory topology: NUMA nodes
and/or interleaving can be adjusted.

Therefore, the SPA value is not part of the "FRU Memory Poison" record
format. And it will not be saved to persistent storage.

However, the SPA values can be helpful during debug and for system
admins during run time.

Save the SPA values in a separate structure. This is updated when
records are restored and when new errors are saved.

  [ bp: Make error messages more user friendly and add and correct
    comments. ]

Signed-off-by: Yazen Ghannam 
Signed-off-by: Borislav Petkov (AMD) 
Link: https://lore.kernel.org/r/20240301143748.854090-3-yazen.ghannam@amd.com

RAS: Export helper to get ras_debugfs_dir

2024-03-01T15:55:10+00:00

Export a getter instead of the debugfs node directly so that, other
in-tree-only RAS modules can use it.

Signed-off-by: Borislav Petkov (AMD) 
Signed-off-by: Yazen Ghannam 
Link: https://lore.kernel.org/r/20240301143748.854090-2-yazen.ghannam@amd.com

RAS/AMD/ATL: Fix bit overflow in denorm_addr_df4_np2()

2024-02-26T12:05:12+00:00

The hash_pa8 and hashed_bit values in denorm_addr_df4_np2() are
currently defined as u8 types. These variables represent single bits.

'hash_pa8' is set based on logical AND operations using masks with more
than 8 bits. So the calculated value will not fit in this variable. It
will always be '0'. The 'hash_pa8' check later in the function will fail
which produces incorrect results for some cases.

Change these variables to bool type. This clarifies that they are
single bit values. Also, this allows the compiler to ensure they hold
the proper results. Remove an unnecessary shift operation.

  [ bp: Remove the unnecessary brackets in the else-branch of the
        hash_pa8 assignment. ]

Fixes: 3f3174996be6 ("RAS: Introduce AMD Address Translation Library")
Signed-off-by: Yazen Ghannam 
Signed-off-by: Borislav Petkov (AMD) 
Link: https://lore.kernel.org/r/20240222165449.23582-1-yazen.ghannam@amd.com

RAS: Introduce a FRU memory poison manager

2024-02-20T17:56:15+00:00

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 
Co-developed-by: 
Signed-off-by: 
Co-developed-by: 
Signed-off-by: 
Tested-by: 
Signed-off-by: Borislav Petkov (AMD) 
Link: https://lore.kernel.org/r/20240214033516.1344948-3-yazen.ghannam@amd.com