[v3,0/3] Add interconnect debugfs client

Message

Mike Tipton Aug. 7, 2023, 2:29 p.m. UTC

This series introduces interconnect debugfs files that support voting
for any path the framework supports.

We've historically relied on an out-of-tree module for this, which used
the old icc_get() that was recently removed in [0]. The old icc_get()
took integer endpoint IDs, which made identifying paths in our old
implementation non-intuitive. The logical node names typically don't
change much chip-to-chip, but the raw integer IDs do. Take this
opportunity to introduce an icc_get() that uses string names instead,
which allows for a more intuitive and generic debugfs interface.

We rely on this support for debug, test, and verification. Hopefully
it'll be useful for other vendors as well.

[0] commit 7dcdad6f32c9 ("interconnect: drop unused icc_get() interface")

Changes in v3:
- Use GFP_ATOMIC when allocating with the rcu lock held.

Changes in v2:
- Make icc_get() an internal interface.
- RCU-protect src_node and dst_node.
- Replace PLATFORM_DEVID_AUTO with PLATFORM_DEVID_NONE.
- Remove unnecessary #include.
- Add debugfs client documentation.

Mike Tipton (3):
  debugfs: Add write support to debugfs_create_str()
  interconnect: Reintroduce icc_get()
  interconnect: Add debugfs test client

 Documentation/driver-api/interconnect.rst |  25 ++++
 drivers/interconnect/Makefile             |   2 +-
 drivers/interconnect/core.c               |  66 +++++++++
 drivers/interconnect/debugfs-client.c     | 168 ++++++++++++++++++++++
 drivers/interconnect/internal.h           |   3 +
 fs/debugfs/file.c                         |  48 ++++++-
 6 files changed, 309 insertions(+), 3 deletions(-)
 create mode 100644 drivers/interconnect/debugfs-client.c