mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-23 16:08:49 -04:00
387aba39b7
Some driver components, like eudebug or ccs-mode, can't be used when VFs are enabled. Add functions to allow those components to block the PF from enabling VFs for the requested duration. Introduce trivial counter to allow lockdown or exclusive access that can be used in the scenarios where we can't follow the strict owner semantics as required by the rw_semaphore implementation. Before enabling VFs, the PF will try to arm the "vfs_enabling" guard for the exclusive access. This will fail if there are some lockdown requests already initiated by the other components. For testing purposes, add debugfs file which will call these new functions from the file's open/close hooks. Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Christoph Manszewski <christoph.manszewski@intel.com> Reviewed-by: Christoph Manszewski <christoph.manszewski@intel.com> Link: https://patch.msgid.link/20251109162451.4779-1-michal.wajdeczko@intel.com