From 60f3eac3a1dc127541817af8042b6711e63dc6e1 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Wed, 6 Sep 2017 19:05:29 +0200 Subject: [PATCH] s390/cmf: simplify cmb_copy_wait No need for refcounting - the data can be on stack. Also change the locking in this function to only use spin_lock_irq (the function waits, thus it's never called from IRQ context). Signed-off-by: Sebastian Ott Reviewed-by: Peter Oberparleiter Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/cmf.c | 72 ++++++++++++++---------------------------- 1 file changed, 23 insertions(+), 49 deletions(-) diff --git a/drivers/s390/cio/cmf.c b/drivers/s390/cio/cmf.c index a8e4c5e13ba8..7ed6c865501b 100644 --- a/drivers/s390/cio/cmf.c +++ b/drivers/s390/cio/cmf.c @@ -319,83 +319,57 @@ static int cmf_copy_block(struct ccw_device *cdev) struct copy_block_struct { wait_queue_head_t wait; int ret; - struct kref kref; }; -static void cmf_copy_block_release(struct kref *kref) -{ - struct copy_block_struct *copy_block; - - copy_block = container_of(kref, struct copy_block_struct, kref); - kfree(copy_block); -} - static int cmf_cmb_copy_wait(struct ccw_device *cdev) { - struct copy_block_struct *copy_block; - int ret; - unsigned long flags; + struct copy_block_struct copy_block; + int ret = -ENODEV; - spin_lock_irqsave(cdev->ccwlock, flags); - if (!cdev->private->cmb) { - ret = -ENODEV; - goto out; - } - copy_block = kzalloc(sizeof(struct copy_block_struct), GFP_ATOMIC); - if (!copy_block) { - ret = -ENOMEM; + spin_lock_irq(cdev->ccwlock); + if (!cdev->private->cmb) goto out; - } - init_waitqueue_head(©_block->wait); - kref_init(©_block->kref); ret = cmf_copy_block(cdev); if (ret != -EBUSY) - goto out_put; + goto out; - if (cdev->private->state != DEV_STATE_ONLINE) { - ret = -EBUSY; - goto out_put; - } + if (cdev->private->state != DEV_STATE_ONLINE) + goto out; + + init_waitqueue_head(©_block.wait); + copy_block.ret = CMF_PENDING; cdev->private->state = DEV_STATE_CMFUPDATE; - copy_block->ret = CMF_PENDING; - cdev->private->cmb_wait = copy_block; + cdev->private->cmb_wait = ©_block; + spin_unlock_irq(cdev->ccwlock); - spin_unlock_irqrestore(cdev->ccwlock, flags); - if (wait_event_interruptible(copy_block->wait, - copy_block->ret != CMF_PENDING)) { - spin_lock_irqsave(cdev->ccwlock, flags); - if (copy_block->ret == CMF_PENDING) { - copy_block->ret = -ERESTARTSYS; + ret = wait_event_interruptible(copy_block.wait, + copy_block.ret != CMF_PENDING); + spin_lock_irq(cdev->ccwlock); + if (ret) { + if (copy_block.ret == CMF_PENDING) { + copy_block.ret = -ERESTARTSYS; if (cdev->private->state == DEV_STATE_CMFUPDATE) cdev->private->state = DEV_STATE_ONLINE; } - spin_unlock_irqrestore(cdev->ccwlock, flags); } - spin_lock_irqsave(cdev->ccwlock, flags); cdev->private->cmb_wait = NULL; - ret = copy_block->ret; -out_put: - kref_put(©_block->kref, cmf_copy_block_release); + ret = copy_block.ret; out: - spin_unlock_irqrestore(cdev->ccwlock, flags); + spin_unlock_irq(cdev->ccwlock); return ret; } void cmf_retry_copy_block(struct ccw_device *cdev) { - struct copy_block_struct *copy_block; + struct copy_block_struct *copy_block = cdev->private->cmb_wait; - copy_block = cdev->private->cmb_wait; - if (!copy_block) { - WARN_ON(1); + if (!copy_block) return; - } - kref_get(©_block->kref); + copy_block->ret = cmf_copy_block(cdev); wake_up(©_block->wait); - kref_put(©_block->kref, cmf_copy_block_release); } static void cmf_generic_reset(struct ccw_device *cdev) -- 2.30.2