From bdab18633a302c82b5e5d5dbc4e38b0baf9c0837 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 20 Sep 2026 08:15:23 -0700 Subject: Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull futex fix from Ingo Molnar: - Also allocate a default private futex hash on vfork() as well, to avoid races with (private) futex waiters (Peter Zijlstra) * tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Also allocate private hash on vfork() --- Documentation/ABI/testing/debugfs-driver-dcc | 127 +++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 Documentation/ABI/testing/debugfs-driver-dcc (limited to 'Documentation/ABI/testing/debugfs-driver-dcc') diff --git a/Documentation/ABI/testing/debugfs-driver-dcc b/Documentation/ABI/testing/debugfs-driver-dcc new file mode 100644 index 000000000..27ed5919d --- /dev/null +++ b/Documentation/ABI/testing/debugfs-driver-dcc @@ -0,0 +1,127 @@ +What: /sys/kernel/debug/dcc/.../ready +Date: December 2022 +Contact: Souradeep Chowdhury +Description: + This file is used to check the status of the dcc + hardware if it's ready to receive user configurations. + A 'Y' here indicates dcc is ready. + +What: /sys/kernel/debug/dcc/.../trigger +Date: December 2022 +Contact: Souradeep Chowdhury +Description: + This is the debugfs interface for manual software + triggers. The trigger can be invoked by writing '1' + to the file. + +What: /sys/kernel/debug/dcc/.../config_reset +Date: December 2022 +Contact: Souradeep Chowdhury +Description: + This file is used to reset the configuration of + a dcc driver to the default configuration. When '1' + is written to the file, all the previous addresses + stored in the driver gets removed and users need to + reconfigure addresses again. + +What: /sys/kernel/debug/dcc/.../[list-number]/config +Date: December 2022 +Contact: Souradeep Chowdhury +Description: + This stores the addresses of the registers which + can be read in case of a hardware crash or manual + software triggers. The input addresses type + can be one of following dcc instructions: read, + write, read-write, and loop type. The lists need to + be configured sequentially and not in a overlapping + manner; e.g. users can jump to list x only after + list y is configured and enabled. The input format for + each type is as follows: + + i) Read instruction + + :: + + echo R >/sys/kernel/debug/dcc/../[list-number]/config + + where: + + + The address to be read. + + + The addresses word count, starting from address <1>. + Each word is 32 bits (4 bytes). If omitted, defaulted + to 1. + + + The bus type, which can be either 'apb' or 'ahb'. + The default is 'ahb' if leaved out. + + ii) Write instruction + + :: + + echo W > /sys/kernel/debug/dcc/../[list-number]/config + + where: + + + The address to be written. + + + The value to be written at . + + + The bus type, which can be either 'apb' or 'ahb'. + + iii) Read-write instruction + + :: + + echo RW > /sys/kernel/debug/dcc/../[list-number]/config + + where: + + + The address to be read and written. + + + The value to be written at . + + + The value mask. + + iv) Loop instruction + + :: + + echo L
... > /sys/kernel/debug/dcc/../[list-number]/config + + where: + + + Number of iterations + +
+ total number of addresses to be written + +
+ Space-separated list of addresses. + +What: /sys/kernel/debug/dcc/.../[list-number]/enable +Date: December 2022 +Contact: Souradeep Chowdhury +Description: + This debugfs interface is used for enabling the + the dcc hardware. A file named "enable" is in the + directory list number where users can enable/disable + the specific list by writing boolean (1 or 0) to the + file. + + On enabling the dcc, all the addresses specified + by the user for the corresponding list is written + into dcc sram which is read by the dcc hardware + on manual or crash induced triggers. Lists must + be configured and enabled sequentially, e.g. list + 2 can only be enabled when list 1 have so. -- cgit v1.3.1