From: Philip J Kelleher <pjk1...@linux.vnet.ibm.com>
The workqueue mechanism has been reworked to prevent soft
lockup issues from occuring by adding in mutex sychronization.
Signed-off-by: Philip J Kelleher <pjk1...@linux.vnet.ibm.com>
-------------------------------------------------------------------------------
diff -uprN -X linux-block-vanilla/Documentation/dontdiff
linux-block-vanilla/drivers/block/rsxx/dma.c
linux-block/drivers/block/rsxx/dma.c
--- linux-block-vanilla/drivers/block/rsxx/dma.c 2013-06-17
16:53:06.805154023 -0500
+++ linux-block/drivers/block/rsxx/dma.c 2013-06-17 16:53:37.564908059
-0500
@@ -381,15 +381,13 @@ static void dma_engine_stalled(unsigned
}
}
-static void rsxx_issue_dmas(struct work_struct *work)
+static void rsxx_issue_dmas(struct rsxx_dma_ctrl *ctrl)
{
- struct rsxx_dma_ctrl *ctrl;
struct rsxx_dma *dma;
int tag;
int cmds_pending = 0;
struct hw_cmd *hw_cmd_buf;
- ctrl = container_of(work, struct rsxx_dma_ctrl, issue_dma_work);
hw_cmd_buf = ctrl->cmd.buf;
if (unlikely(ctrl->card->halt) ||
@@ -469,9 +467,8 @@ static void rsxx_issue_dmas(struct work_
}
}
-static void rsxx_dma_done(struct work_struct *work)
+static void rsxx_dma_done(struct rsxx_dma_ctrl *ctrl)
{
- struct rsxx_dma_ctrl *ctrl;
struct rsxx_dma *dma;
unsigned long flags;
u16 count;
@@ -479,7 +476,6 @@ static void rsxx_dma_done(struct work_st
u8 tag;
struct hw_status *hw_st_buf;
- ctrl = container_of(work, struct rsxx_dma_ctrl, dma_done_work);
hw_st_buf = ctrl->status.buf;
if (unlikely(ctrl->card->halt) ||
@@ -555,6 +551,28 @@ static void rsxx_dma_done(struct work_st
spin_unlock_bh(&ctrl->queue_lock);
}
+static void rsxx_schedule_issue(struct work_struct *work)
+{
+ struct rsxx_dma_ctrl *ctrl;
+
+ ctrl = container_of(work, struct rsxx_dma_ctrl, issue_dma_work);
+
+ mutex_lock(&ctrl->work_lock);
+ rsxx_issue_dmas(ctrl);
+ mutex_unlock(&ctrl->work_lock);
+}
+
+static void rsxx_schedule_done(struct work_struct *work)
+{
+ struct rsxx_dma_ctrl *ctrl;
+
+ ctrl = container_of(work, struct rsxx_dma_ctrl, dma_done_work);
+
+ mutex_lock(&ctrl->work_lock);
+ rsxx_dma_done(ctrl);
+ mutex_unlock(&ctrl->work_lock);
+}
+
static int rsxx_queue_discard(struct rsxx_cardinfo *card,
struct list_head *q,
unsigned int laddr,
@@ -789,6 +807,7 @@ static int rsxx_dma_ctrl_init(struct pci
spin_lock_init(&ctrl->trackers->lock);
spin_lock_init(&ctrl->queue_lock);
+ mutex_init(&ctrl->work_lock);
INIT_LIST_HEAD(&ctrl->queue);
setup_timer(&ctrl->activity_timer, dma_engine_stalled,
@@ -802,8 +821,8 @@ static int rsxx_dma_ctrl_init(struct pci
if (!ctrl->done_wq)
return -ENOMEM;
- INIT_WORK(&ctrl->issue_dma_work, rsxx_issue_dmas);
- INIT_WORK(&ctrl->dma_done_work, rsxx_dma_done);
+ INIT_WORK(&ctrl->issue_dma_work, rsxx_schedule_issue);
+ INIT_WORK(&ctrl->dma_done_work, rsxx_schedule_done);
st = rsxx_hw_buffers_init(dev, ctrl);
if (st)
diff -uprN -X linux-block-vanilla/Documentation/dontdiff
linux-block-vanilla/drivers/block/rsxx/rsxx_priv.h
linux-block/drivers/block/rsxx/rsxx_priv.h
--- linux-block-vanilla/drivers/block/rsxx/rsxx_priv.h 2013-06-17
16:53:06.812153024 -0500
+++ linux-block/drivers/block/rsxx/rsxx_priv.h 2013-06-17 16:53:37.572905400
-0500
@@ -115,6 +115,7 @@ struct rsxx_dma_ctrl {
struct timer_list activity_timer;
struct dma_tracker_list *trackers;
struct rsxx_dma_stats stats;
+ struct mutex work_lock;
};
struct rsxx_cardinfo {
--
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