From 5307e2ad69ab3b0e0622fdf8b254c1d4565eb924 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Thu, 12 Oct 2017 12:40:10 +0200 Subject: bitops: Introduce assign_bit() A common idiom is to assign a value to a bit with: if (value) set_bit(nr, addr); else clear_bit(nr, addr); Likewise common is the one-line expression variant: value ? set_bit(nr, addr) : clear_bit(nr, addr); Commit 9a8ac3ae682e ("dm mpath: cleanup QUEUE_IF_NO_PATH bit manipulation by introducing assign_bit()") introduced assign_bit() to the md subsystem for brevity. Make it available to others, specifically gpiolib and the upcoming driver for Maxim MAX3191x industrial serializer chips. As requested by Peter Zijlstra, change the argument order to reflect traditional "dst = src" in C, hence "assign_bit(nr, addr, value)". Cc: Bart Van Assche Cc: Alasdair Kergon Cc: Mike Snitzer Cc: Linus Walleij Cc: Neil Brown Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Theodore Ts'o Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Denys Vlasenko Acked-by: Andrew Morton Signed-off-by: Lukas Wunner Signed-off-by: Linus Walleij --- drivers/md/dm-mpath.c | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-) (limited to 'drivers/md/dm-mpath.c') diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 11f273d2f018..0e211de9bc54 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -641,14 +641,6 @@ static void process_queued_bios(struct work_struct *work) blk_finish_plug(&plug); } -static void assign_bit(bool value, long nr, unsigned long *addr) -{ - if (value) - set_bit(nr, addr); - else - clear_bit(nr, addr); -} - /* * If we run out of usable paths, should we queue I/O or error it? */ @@ -658,11 +650,11 @@ static int queue_if_no_path(struct multipath *m, bool queue_if_no_path, unsigned long flags; spin_lock_irqsave(&m->lock, flags); - assign_bit((save_old_value && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) || - (!save_old_value && queue_if_no_path), - MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags); - assign_bit(queue_if_no_path || dm_noflush_suspending(m->ti), - MPATHF_QUEUE_IF_NO_PATH, &m->flags); + assign_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags, + (save_old_value && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) || + (!save_old_value && queue_if_no_path)); + assign_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags, + queue_if_no_path || dm_noflush_suspending(m->ti)); spin_unlock_irqrestore(&m->lock, flags); if (!queue_if_no_path) { @@ -1588,8 +1580,8 @@ static void multipath_resume(struct dm_target *ti) unsigned long flags; spin_lock_irqsave(&m->lock, flags); - assign_bit(test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags), - MPATHF_QUEUE_IF_NO_PATH, &m->flags); + assign_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags, + test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags)); spin_unlock_irqrestore(&m->lock, flags); } -- cgit v1.2.3