[PATCH v3 0/3] ACPI: Add support for ACPI RAS2 feature table

[<shiju.jose@huawei.com>]

From: Shiju Jose <shiju.jose@huawei.com>

Add support for ACPI RAS2 feature table (RAS2) defined in the
ACPI 6.5 specification, section 5.2.21 and RAS2 HW based memory
scrubbing feature.

ACPI RAS2 patches were part of the EDAC series [1].

The code is based on ras.git: edac-cxl branch [2].

1. https://lore.kernel.org/linux-cxl/20250212143654.1893-1-shiju.jose@huawei.com/
2. https://web.git.kernel.org/pub/scm/linux/kernel/git/ras/ras.git/log/?h=edac-cxl

Changes
=======
v2 -> v3:
1. Rename RAS2 table structure and field names in 
   include/acpi/actbl2.h limited to only necessary
   for RAS2 scrub feature. Not for merging.
   Corresponding changes are merged in the acpica:
   https://github.com/acpica/acpica/commit/2c8a38f747de9d977491a494faf0dfaf799b777b
2. Changes for feedbacks from Jonathan on v2.
3. Daniel reported a known behaviour: when readback 'size' attribute after
   setting in, returns 0 before starting scrubbing via 'addr' attribute.
   Changes added to fix this.
4. Daniel reported that firmware cannot update status of demand scrubbing
   via the 'Actual Address Range (OUTPUT)', thus add workaround in the
   kernel to update sysfs 'addr' attribute with the status of demand
   scrubbing.
5. Optimized logic in ras2_check_pcc_chan() function
   (patch - ACPI:RAS2: Add ACPI RAS2 driver).
6. Add PCC channel lock to struct ras2_pcc_subspace and change
   lock in ras2_mem_ctx as a pointer to pcc channel lock to make sure
   writing to PCC subspace shared memory is protected from race conditions.
   
v1 -> v2:
1.  Changes for feedbacks from Borislav.
    - Shorten ACPI RAS2 structures and variables names.
    - Shorten some of the other variables in the RAS2 drivers.
    - Fixed few CamelCases.

2.  Changes for feedbacks from Yazen.
    - Added newline after number of '}' and return statements.
    - Changed return type for "ras2_add_aux_device() to 'int'.
    - Deleted a duplication of acpi_get_table("RAS2",...) in the ras2_acpi_parse_table().
    - Add "FW_WARN" to few error logs in the ras2_acpi_parse_table().
    - Rename ras2_acpi_init() to acpi_ras2_init() and modified to call acpi_ras2_init()
      function from the acpi_init().
    - Moved scrub related variables from the struct ras2_mem_ctx from  patch
      "ACPI:RAS2: Add ACPI RAS2 driver" to "ras: mem: Add memory ACPI RAS2 driver".  

Shiju Jose (3):
  ACPI: ACPI 6.5: RAS2: Rename RAS2 table structure and field names
  ACPI:RAS2: Add ACPI RAS2 driver
  ras: mem: Add memory ACPI RAS2 driver

 Documentation/edac/scrub.rst |  76 +++++++
 drivers/acpi/Kconfig         |  11 +
 drivers/acpi/Makefile        |   1 +
 drivers/acpi/bus.c           |   3 +
 drivers/acpi/ras2.c          | 420 +++++++++++++++++++++++++++++++++++
 drivers/ras/Kconfig          |  11 +
 drivers/ras/Makefile         |   1 +
 drivers/ras/acpi_ras2.c      | 406 +++++++++++++++++++++++++++++++++
 include/acpi/actbl2.h        |  16 +-
 include/acpi/ras2.h          |  51 +++++
 10 files changed, 988 insertions(+), 8 deletions(-)
 create mode 100644 drivers/acpi/ras2.c
 create mode 100644 drivers/ras/acpi_ras2.c
 create mode 100644 include/acpi/ras2.h

-- 
2.43.0