[PATCH] dmaengine: idxd: device cmd should use dedicated lock

[Dave Jiang <dave.jiang@xxxxxxxxx>]

Create a dedicated lock for device command operations. Put the device
command operation under finer grained locking instead of using the
idxd->dev_lock.

Suggested-by: Sanjay Kumar <sanjay.k.kumar@xxxxxxxxx>
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
---
 drivers/dma/idxd/device.c |   18 +++++++++---------
 drivers/dma/idxd/idxd.h   |    1 +
 drivers/dma/idxd/init.c   |    1 +
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 3934e660d951..420b93fe5feb 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -465,13 +465,13 @@ int idxd_device_init_reset(struct idxd_device *idxd)
 	memset(&cmd, 0, sizeof(cmd));
 	cmd.cmd = IDXD_CMD_RESET_DEVICE;
 	dev_dbg(dev, "%s: sending reset for init.\n", __func__);
-	spin_lock_irqsave(&idxd->dev_lock, flags);
+	spin_lock_irqsave(&idxd->cmd_lock, flags);
 	iowrite32(cmd.bits, idxd->reg_base + IDXD_CMD_OFFSET);
 
 	while (ioread32(idxd->reg_base + IDXD_CMDSTS_OFFSET) &
 	       IDXD_CMDSTS_ACTIVE)
 		cpu_relax();
-	spin_unlock_irqrestore(&idxd->dev_lock, flags);
+	spin_unlock_irqrestore(&idxd->cmd_lock, flags);
 	return 0;
 }
 
@@ -494,10 +494,10 @@ static void idxd_cmd_exec(struct idxd_device *idxd, int cmd_code, u32 operand,
 	cmd.operand = operand;
 	cmd.int_req = 1;
 
-	spin_lock_irqsave(&idxd->dev_lock, flags);
+	spin_lock_irqsave(&idxd->cmd_lock, flags);
 	wait_event_lock_irq(idxd->cmd_waitq,
 			    !test_bit(IDXD_FLAG_CMD_RUNNING, &idxd->flags),
-			    idxd->dev_lock);
+			    idxd->cmd_lock);
 
 	dev_dbg(&idxd->pdev->dev, "%s: sending cmd: %#x op: %#x\n",
 		__func__, cmd_code, operand);
@@ -511,9 +511,9 @@ static void idxd_cmd_exec(struct idxd_device *idxd, int cmd_code, u32 operand,
 	 * After command submitted, release lock and go to sleep until
 	 * the command completes via interrupt.
 	 */
-	spin_unlock_irqrestore(&idxd->dev_lock, flags);
+	spin_unlock_irqrestore(&idxd->cmd_lock, flags);
 	wait_for_completion(&done);
-	spin_lock_irqsave(&idxd->dev_lock, flags);
+	spin_lock_irqsave(&idxd->cmd_lock, flags);
 	if (status) {
 		*status = ioread32(idxd->reg_base + IDXD_CMDSTS_OFFSET);
 		idxd->cmd_status = *status & GENMASK(7, 0);
@@ -522,7 +522,7 @@ static void idxd_cmd_exec(struct idxd_device *idxd, int cmd_code, u32 operand,
 	__clear_bit(IDXD_FLAG_CMD_RUNNING, &idxd->flags);
 	/* Wake up other pending commands */
 	wake_up(&idxd->cmd_waitq);
-	spin_unlock_irqrestore(&idxd->dev_lock, flags);
+	spin_unlock_irqrestore(&idxd->cmd_lock, flags);
 }
 
 int idxd_device_enable(struct idxd_device *idxd)
@@ -667,13 +667,13 @@ int idxd_device_release_int_handle(struct idxd_device *idxd, int handle,
 
 	dev_dbg(dev, "cmd: %u operand: %#x\n", IDXD_CMD_RELEASE_INT_HANDLE, operand);
 
-	spin_lock_irqsave(&idxd->dev_lock, flags);
+	spin_lock_irqsave(&idxd->cmd_lock, flags);
 	iowrite32(cmd.bits, idxd->reg_base + IDXD_CMD_OFFSET);
 
 	while (ioread32(idxd->reg_base + IDXD_CMDSTS_OFFSET) & IDXD_CMDSTS_ACTIVE)
 		cpu_relax();
 	status = ioread32(idxd->reg_base + IDXD_CMDSTS_OFFSET);
-	spin_unlock_irqrestore(&idxd->dev_lock, flags);
+	spin_unlock_irqrestore(&idxd->cmd_lock, flags);
 
 	if ((status & IDXD_CMDSTS_ERR_MASK) != IDXD_CMDSTS_SUCCESS) {
 		dev_dbg(dev, "release int handle failed: %#x\n", status);
diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index 7237f3e15a5e..97c96ca6ab70 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -204,6 +204,7 @@ struct idxd_device {
 	void __iomem *reg_base;
 
 	spinlock_t dev_lock;	/* spinlock for device */
+	spinlock_t cmd_lock;	/* spinlock for device commands */
 	struct completion *cmd_done;
 	struct idxd_group **groups;
 	struct idxd_wq **wqs;
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index 36b33eef5aa2..8003f8a25fff 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -449,6 +449,7 @@ static struct idxd_device *idxd_alloc(struct pci_dev *pdev, struct idxd_driver_d
 	}
 
 	spin_lock_init(&idxd->dev_lock);
+	spin_lock_init(&idxd->cmd_lock);
 
 	return idxd;
 }