* Mark Rutland <mark.rutl...@arm.com> wrote:
> From: Peter Zijlstra <pet...@infradead.org> > > Mark found ldsem_cmpxchg() needed an (atomic_long_t *) cast to keep > working after making the atomic_long interface type safe. > > Needing casts is bad form, which made me look at the code. There are no > ld_semaphore::count users outside of these functions so there is no > reason why it can not be an atomic_long_t in the first place, obviating > the need for this cast. > > That also ensures the loads use atomic_long_read(), which implies (at > least) READ_ONCE() in order to guarantee single-copy-atomic loads. > > When using atomic_long_try_cmpxchg() the ldsem_cmpxchg() wrapper gets > very thin (the only difference is not changing *old on success, which > most callers don't seem to care about). > > So rework the whole thing to use atomic_long_t and its accessors > directly. > > While there, fixup all the horrible comment styles. > > Cc: Peter Hurley <pe...@hurleysoftware.com> > Acked-by: Will Deacon <will.dea...@arm.com> > Reported-by: Mark Rutland <mark.rutl...@arm.com> > Reviewed-by: Andy Shevchenko <andy.shevche...@gmail.com> > Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> > Signed-off-by: Mark Rutland <mark.rutl...@arm.com> > Cc: Ingo Molnar <mi...@kernel.org> > --- > drivers/tty/tty_ldsem.c | 82 > ++++++++++++++++++++--------------------------- > include/linux/tty_ldisc.h | 4 +-- > 2 files changed, 37 insertions(+), 49 deletions(-) > > Note: Greg has queued this via the in the tty tree for v4.19, which can be > seen at: > > https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git/commit/?h=tty-next&id=5fd691afdf929061c391d897fa627822c3b2fd5a Can this patch be skipped, or do the others depend on it? Thanks, Ingo
