[ndctl PATCH v7 0/7] Add error injection support

[Ben Cheatham <Benjamin.Cheatham@amd.com>]

v7 Changes:
	- Use PATH_MAX instead of strlen(ctx->cxl_debugfs) for debugfs paths (Dave)
	- Add goto for error paths to memdev poison functions in patch 3/7 (Dave)
	- Add Dave's Reviewed-by tags

v6 Changes:
	- Rebase to pending branch (Alison)
	- Drop const for ctx->debugfs (Alison)
	- Rename get_debugfs_dir() to get_cxl_debugfs_dir() and return cxl directory in debugfs
	(i.e. "/sys/kernel/debug" -> "/sys/kernel/debug/cxl")
	- Rename ctx->debugfs to ctx->cxl_debugfs
	- Fix missing free of einj path (Alison)
	- Add protocol errors in order to perrors list (Alison)
	- Use hex constants instead of BIT() for protocol errors (Alison)
	- Add symbols to LIBCXL_11 instead of LIBCXL_10 (Alison)
	- Update commit message to reflect util_cxl_dport_filter() behavior (Alison)
	- Remove EINJ_TYPES_BUF_SIZE #ifdef (Alison)
	- Fix type mismatch of addr in poison_action() (Alison)
	- Fix inject_action() to catch missing 'type' option (Alison)
	- Remove '-N' option and show the information behind that option by default when
	CXL debugfs is present (Alison)
	- Add 'protocol_injectable' attribute for dports (Alison)
	- Update inject-error man page with port injection example (Alison)
	- Add warning to inject-error man page (Alison)

v5 Changes:
	- Use setmntent()/getmntent() instead of open-coding getting the
	  debugfs path (Dave)
	- Use correct return code for sysfs_read_attr() (Dave)

v4 Changes:
	- Variable renames for clarity (Dave)
	- Use errno instead of rc for access() calls (Dave)
	- Check returns for snprintf() (Dave)
	- Add util_cxl_dport_filter() (Dave)
	- Replace printf() calls with log_info() (Dave)
	- Write correct value to debugfs during protocol error injection
	(BIT(error) vs. error)

v3 Changes:
	- Rebase on v83 release
	- Fix whitespace errors (Alison)

This series adds support for injecting CXL protocol (CXL.cache/mem)
errors[1] into CXL RCH Downstream ports and VH root ports[2] and
poison into CXL memory devices through the CXL debugfs. Errors are
injected using a new 'inject-error' command. Device poison can be
cleared using the 'clear-error' command. The 'inject-error' and
'clear-error' commands require access to the CXL driver's debugfs.

The documentation for the new cxl-inject-error command shows both usage
and the possible device/error types, as well as how to retrieve them
using cxl-list. cxl-list has been updated to include the possible error
types for protocol error injection (under the "bus" object) and which CXL
dports and memory devices support injection.

[1]: ACPI v6.5 spec, section 18.6.4
[2]: ACPI v6.5 spec, table 18.31

Ben Cheatham (7):
  libcxl: Add debugfs path to CXL context
  libcxl: Add CXL protocol errors
  libcxl: Add poison injection support
  cxl: Add inject-error command
  cxl: Add clear-error command
  cxl/list: Add injectable errors in output
  Documentation: Add docs for inject/clear-error commands

 Documentation/cxl/cxl-clear-error.txt  |  69 ++++++
 Documentation/cxl/cxl-inject-error.txt | 161 ++++++++++++
 Documentation/cxl/meson.build          |   2 +
 cxl/builtin.h                          |   2 +
 cxl/cxl.c                              |   2 +
 cxl/filter.c                           |  26 ++
 cxl/filter.h                           |   2 +
 cxl/inject-error.c                     | 248 +++++++++++++++++++
 cxl/json.c                             |  38 +++
 cxl/lib/libcxl.c                       | 327 +++++++++++++++++++++++++
 cxl/lib/libcxl.sym                     |  10 +
 cxl/lib/private.h                      |  14 ++
 cxl/libcxl.h                           |  18 ++
 cxl/meson.build                        |   1 +
 14 files changed, 920 insertions(+)
 create mode 100644 Documentation/cxl/cxl-clear-error.txt
 create mode 100644 Documentation/cxl/cxl-inject-error.txt
 create mode 100644 cxl/inject-error.c

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2.52.0