From d03fcf50ba56f4479685b951506422eeca230853 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 11 Jul 2025 16:49:32 -0700 Subject: cxl: Convert to ACQUIRE() for conditional rwsem locking Use ACQUIRE() to cleanup conditional locking paths in the CXL driver The ACQUIRE() macro and its associated ACQUIRE_ERR() helpers, like scoped_cond_guard(), arrange for scoped-based conditional locking. Unlike scoped_cond_guard(), these macros arrange for an ERR_PTR() to be retrieved representing the state of the conditional lock. The goal of this conversion is to complete the removal of all explicit unlock calls in the subsystem. I.e. the methods to acquire a lock are solely via guard(), scoped_guard() (for limited cases), or ACQUIRE(). All unlock is implicit / scope-based. In order to make sure all lock sites are converted, the existing rwsem's are consolidated and renamed in 'struct cxl_rwsem'. While that makes the patch noisier it gives a clean cut-off between old-world (explicit unlock allowed), and new world (explicit unlock deleted). Cc: David Lechner Cc: Peter Zijlstra Cc: Linus Torvalds Cc: Ingo Molnar Cc: Fabio M. De Francesco Cc: Davidlohr Bueso Cc: Jonathan Cameron Cc: Dave Jiang Cc: Alison Schofield Cc: Vishal Verma Cc: Ira Weiny Cc: Shiju Jose Acked-by: Peter Zijlstra (Intel) Signed-off-by: Dan Williams Reviewed-by: Jonathan Cameron Reviewed-by: Fabio M. De Francesco Reviewed-by: Dave Jiang Tested-by: Shiju Jose Link: https://patch.msgid.link/20250711234932.671292-9-dan.j.williams@intel.com Signed-off-by: Dave Jiang --- include/linux/rwsem.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index c810deb88d13..cbafdc12e743 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -244,6 +244,7 @@ DEFINE_GUARD_COND(rwsem_read, _intr, down_read_interruptible(_T), _RET == 0) DEFINE_GUARD(rwsem_write, struct rw_semaphore *, down_write(_T), up_write(_T)) DEFINE_GUARD_COND(rwsem_write, _try, down_write_trylock(_T)) +DEFINE_GUARD_COND(rwsem_write, _kill, down_write_killable(_T), _RET == 0) /* * downgrade write lock to read lock -- cgit v1.2.3