From 0cbf768ef834c810d1eab205f21a434b9356d329 Mon Sep 17 00:00:00 2001 From: "Stephen M. Cameron" Date: Fri, 14 Nov 2014 17:27:09 -0600 Subject: [PATCH] hpsa: use atomics for commands_outstanding Use atomics for commands_outstanding instead of protecting with spin locks. Signed-off-by: Don Brace Signed-off-by: Stephen M. Cameron Reviewed-by: Joe Handzik Signed-off-by: Christoph Hellwig --- drivers/scsi/hpsa.c | 26 +++++++++----------------- drivers/scsi/hpsa.h | 27 +++++++-------------------- 2 files changed, 16 insertions(+), 37 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 diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h index 80fa9a99b692..8e06d9e280ec 100644 --- a/drivers/scsi/hpsa.h +++ b/drivers/scsi/hpsa.h @@ -118,7 +118,7 @@ struct ctlr_info { struct CfgTable __iomem *cfgtable; int interrupts_enabled; int max_commands; - int commands_outstanding; + atomic_t commands_outstanding; # define PERF_MODE_INT 0 # define DOORBELL_INT 1 # define SIMPLE_MODE_INT 2 @@ -395,7 +395,7 @@ static void SA5_performant_intr_mask(struct ctlr_info *h, unsigned long val) static unsigned long SA5_performant_completed(struct ctlr_info *h, u8 q) { struct reply_queue_buffer *rq = &h->reply_queue[q]; - unsigned long flags, register_value = FIFO_EMPTY; + unsigned long register_value = FIFO_EMPTY; /* msi auto clears the interrupt pending bit. */ if (!(h->msi_vector || h->msix_vector)) { @@ -413,9 +413,7 @@ static unsigned long SA5_performant_completed(struct ctlr_info *h, u8 q) if ((rq->head[rq->current_entry] & 1) == rq->wraparound) { register_value = 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 { register_value = FIFO_EMPTY; } @@ -433,11 +431,7 @@ static unsigned long SA5_performant_completed(struct ctlr_info *h, u8 q) */ static unsigned long SA5_fifo_full(struct ctlr_info *h) { - if (h->commands_outstanding >= h->max_commands) - return 1; - else - return 0; - + return atomic_read(&h->commands_outstanding) >= h->max_commands; } /* * returns value read from hardware. @@ -448,13 +442,9 @@ static unsigned long SA5_completed(struct ctlr_info *h, { unsigned long register_value = readl(h->vaddr + SA5_REPLY_PORT_OFFSET); - unsigned long flags; - if (register_value != FIFO_EMPTY) { - spin_lock_irqsave(&h->lock, flags); - h->commands_outstanding--; - spin_unlock_irqrestore(&h->lock, flags); - } + if (register_value != FIFO_EMPTY) + atomic_dec(&h->commands_outstanding); #ifdef HPSA_DEBUG if (register_value != FIFO_EMPTY) @@ -510,7 +500,6 @@ static unsigned long SA5_ioaccel_mode1_completed(struct ctlr_info *h, u8 q) { u64 register_value; struct reply_queue_buffer *rq = &h->reply_queue[q]; - unsigned long flags; BUG_ON(q >= h->nreply_queues); @@ -528,9 +517,7 @@ static unsigned long SA5_ioaccel_mode1_completed(struct ctlr_info *h, u8 q) wmb(); writel((q << 24) | rq->current_entry, h->vaddr + IOACCEL_MODE1_CONSUMER_INDEX); - spin_lock_irqsave(&h->lock, flags); - h->commands_outstanding--; - spin_unlock_irqrestore(&h->lock, flags); + atomic_dec(&h->commands_outstanding); } return (unsigned long) register_value; } -- 2.30.2