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author | Stephen M. Cameron <stephenmcameron@gmail.com> | 2014-11-15 00:27:09 +0100 |
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committer | Christoph Hellwig <hch@lst.de> | 2014-11-20 09:11:25 +0100 |
commit | 0cbf768ef834c810d1eab205f21a434b9356d329 (patch) | |
tree | 874822da5ceeb78fc03bebd59e2b0ee545cc23e2 /drivers/scsi/hpsa.c | |
parent | hpsa: get rid of type/attribute/direction bit field where possible (diff) | |
download | linux-0cbf768ef834c810d1eab205f21a434b9356d329.tar.xz linux-0cbf768ef834c810d1eab205f21a434b9356d329.zip |
hpsa: use atomics for commands_outstanding
Use atomics for commands_outstanding instead of protecting with spin locks.
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Stephen M. Cameron <stephenmcameron@gmail.com>
Reviewed-by: Joe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/scsi/hpsa.c')
-rw-r--r-- | drivers/scsi/hpsa.c | 26 |
1 files changed, 9 insertions, 17 deletions
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index f028ae4a04be..c079bb94f86b 100644 --- a/drivers/scsi/hpsa.c +++ b/drivers/scsi/hpsa.c @@ -394,7 +394,8 @@ static ssize_t host_show_commands_outstanding(struct device *dev, struct Scsi_Host *shost = class_to_shost(dev); struct ctlr_info *h = shost_to_hba(shost); - return snprintf(buf, 20, "%d\n", h->commands_outstanding); + return snprintf(buf, 20, "%d\n", + atomic_read(&h->commands_outstanding)); } static ssize_t host_show_transport_mode(struct device *dev, @@ -700,7 +701,6 @@ static inline u32 next_command(struct ctlr_info *h, u8 q) { u32 a; struct reply_queue_buffer *rq = &h->reply_queue[q]; - unsigned long flags; if (h->transMethod & CFGTBL_Trans_io_accel1) return h->access.command_completed(h, q); @@ -711,9 +711,7 @@ static inline u32 next_command(struct ctlr_info *h, u8 q) if ((rq->head[rq->current_entry] & 1) == rq->wraparound) { a = rq->head[rq->current_entry]; rq->current_entry++; - spin_lock_irqsave(&h->lock, flags); - h->commands_outstanding--; - spin_unlock_irqrestore(&h->lock, flags); + atomic_dec(&h->commands_outstanding); } else { a = FIFO_EMPTY; } @@ -5445,15 +5443,9 @@ static void start_io(struct ctlr_info *h, unsigned long *flags) /* Put job onto the completed Q */ addQ(&h->cmpQ, c); - - /* Must increment commands_outstanding before unlocking - * and submitting to avoid race checking for fifo full - * condition. - */ - h->commands_outstanding++; - - /* Tell the controller execute command */ + atomic_inc(&h->commands_outstanding); spin_unlock_irqrestore(&h->lock, *flags); + /* Tell the controller execute command */ h->access.submit_command(h, c); spin_lock_irqsave(&h->lock, *flags); } @@ -5499,6 +5491,7 @@ static inline void finish_cmd(struct CommandList *c) unsigned long flags; int io_may_be_stalled = 0; struct ctlr_info *h = c->h; + int count; spin_lock_irqsave(&h->lock, flags); removeQ(c); @@ -5519,11 +5512,10 @@ static inline void finish_cmd(struct CommandList *c) * want to get in a cycle where we call start_io every time * through here. */ - if (unlikely(h->fifo_recently_full) && - h->commands_outstanding < 5) - io_may_be_stalled = 1; - + count = atomic_read(&h->commands_outstanding); spin_unlock_irqrestore(&h->lock, flags); + if (unlikely(h->fifo_recently_full) && count < 5) + io_may_be_stalled = 1; dial_up_lockup_detection_on_fw_flash_complete(c->h, c); if (likely(c->cmd_type == CMD_IOACCEL1 || c->cmd_type == CMD_SCSI |