From 0b57075deb3c082db6fbf528f3f6a3854b81bd83 Mon Sep 17 00:00:00 2001 From: "Stephen M. Cameron" Date: Thu, 29 May 2014 10:53:28 -0500 Subject: [PATCH] hpsa: Rearrange start_io to avoid one unlock/lock sequence in main io path Signed-off-by: Stephen M. Cameron Reviewed-by: Joe Handzik Signed-off-by: Christoph Hellwig --- drivers/scsi/hpsa.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index 3e501df02e35..0a30cc23e718 100644 --- a/drivers/scsi/hpsa.c +++ b/drivers/scsi/hpsa.c @@ -194,7 +194,8 @@ static int number_of_controllers; static irqreturn_t do_hpsa_intr_intx(int irq, void *dev_id); static irqreturn_t do_hpsa_intr_msi(int irq, void *dev_id); static int hpsa_ioctl(struct scsi_device *dev, int cmd, void *arg); -static void start_io(struct ctlr_info *h); +static void lock_and_start_io(struct ctlr_info *h); +static void start_io(struct ctlr_info *h, unsigned long *flags); #ifdef CONFIG_COMPAT static int hpsa_compat_ioctl(struct scsi_device *dev, int cmd, void *arg); @@ -845,8 +846,8 @@ static void enqueue_cmd_and_start_io(struct ctlr_info *h, spin_lock_irqsave(&h->lock, flags); addQ(&h->reqQ, c); h->Qdepth++; + start_io(h, &flags); spin_unlock_irqrestore(&h->lock, flags); - start_io(h); } static inline void removeQ(struct CommandList *c) @@ -5459,13 +5460,12 @@ static void __iomem *remap_pci_mem(ulong base, ulong size) /* Takes cmds off the submission queue and sends them to the hardware, * then puts them on the queue of cmds waiting for completion. + * Assumes h->lock is held */ -static void start_io(struct ctlr_info *h) +static void start_io(struct ctlr_info *h, unsigned long *flags) { struct CommandList *c; - unsigned long flags; - spin_lock_irqsave(&h->lock, flags); while (!list_empty(&h->reqQ)) { c = list_entry(h->reqQ.next, struct CommandList, list); /* can't do anything if fifo is full */ @@ -5490,10 +5490,18 @@ static void start_io(struct ctlr_info *h) h->commands_outstanding++; /* Tell the controller execute command */ - spin_unlock_irqrestore(&h->lock, flags); + spin_unlock_irqrestore(&h->lock, *flags); h->access.submit_command(h, c); - spin_lock_irqsave(&h->lock, flags); + spin_lock_irqsave(&h->lock, *flags); } +} + +static void lock_and_start_io(struct ctlr_info *h) +{ + unsigned long flags; + + spin_lock_irqsave(&h->lock, flags); + start_io(h, &flags); spin_unlock_irqrestore(&h->lock, flags); } @@ -5561,7 +5569,7 @@ static inline void finish_cmd(struct CommandList *c) else if (c->cmd_type == CMD_IOCTL_PEND) complete(c->waiting); if (unlikely(io_may_be_stalled)) - start_io(h); + lock_and_start_io(h); } static inline u32 hpsa_tag_contains_index(u32 tag) -- 2.34.1