The NTB .peer_db_set() callback may be invoked from atomic context.
pci-epf-vntb currently calls pci_epc_raise_irq() directly, but
pci_epc_raise_irq() may sleep (it takes epc->lock).

Avoid sleeping in atomic context by coalescing doorbell bits into an
atomic64 pending mask and raising MSIs from a work item. Limit the
amount of work per run to avoid monopolizing the workqueue under a
doorbell storm.

Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
Signed-off-by: Koichiro Den <den@valinux.co.jp>
---
Changes since v1:
  - No functional changes.
  - Updated comment in vntb_epf_peer_db_work().

 drivers/pci/endpoint/functions/pci-epf-vntb.c | 106 +++++++++++++-----
 1 file changed, 78 insertions(+), 28 deletions(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
index 83372aba5106..e2c0b6dba793 100644
--- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
@@ -69,6 +69,9 @@ static struct workqueue_struct *kpcintb_workqueue;
 #define MAX_DB_COUNT			32
 #define MAX_MW				4
 
+/* Limit per-work execution to avoid monopolizing kworker on doorbell storms. */
+#define VNTB_PEER_DB_WORK_BUDGET	5
+
 enum epf_ntb_bar {
 	BAR_CONFIG,
 	BAR_DB,
@@ -129,6 +132,8 @@ struct epf_ntb {
 	u32 spad_count;
 	u64 mws_size[MAX_MW];
 	atomic64_t db;
+	atomic64_t peer_db_pending;
+	struct work_struct peer_db_work;
 	u32 vbus_number;
 	u16 vntb_pid;
 	u16 vntb_vid;
@@ -933,6 +938,8 @@ static int epf_ntb_epc_init(struct epf_ntb *ntb)
 	INIT_DELAYED_WORK(&ntb->cmd_handler, epf_ntb_cmd_handler);
 	queue_work(kpcintb_workqueue, &ntb->cmd_handler.work);
 
+	enable_work(&ntb->peer_db_work);
+
 	return 0;
 
 err_write_header:
@@ -955,6 +962,7 @@ static int epf_ntb_epc_init(struct epf_ntb *ntb)
  */
 static void epf_ntb_epc_cleanup(struct epf_ntb *ntb)
 {
+	disable_work_sync(&ntb->peer_db_work);
 	epf_ntb_mw_bar_clear(ntb, ntb->num_mws);
 	epf_ntb_db_bar_clear(ntb);
 	epf_ntb_config_sspad_bar_clear(ntb);
@@ -1369,41 +1377,79 @@ static int vntb_epf_peer_spad_write(struct ntb_dev *ndev, int pidx, int idx, u32
 	return 0;
 }
 
+static void vntb_epf_peer_db_work(struct work_struct *work)
+{
+	struct epf_ntb *ntb = container_of(work, struct epf_ntb, peer_db_work);
+	struct pci_epf *epf = ntb->epf;
+	unsigned int budget = VNTB_PEER_DB_WORK_BUDGET;
+	u8 func_no, vfunc_no;
+	u32 interrupt_num;
+	u64 db_bits;
+	int ret;
+
+	if (!epf || !epf->epc)
+		return;
+
+	func_no = epf->func_no;
+	vfunc_no = epf->vfunc_no;
+
+	/*
+	 * Drain doorbells from peer_db_pending in snapshots (atomic64_xchg()).
+	 * Limit the number of snapshots handled per run so we don't monopolize
+	 * the workqueue under a doorbell storm.
+	 */
+	while (budget--) {
+		db_bits = atomic64_xchg(&ntb->peer_db_pending, 0);
+		if (!db_bits)
+			return;
+
+		while (db_bits) {
+			/*
+			 * pci_epc_raise_irq() for MSI expects a 1-based
+			 * interrupt number. ffs() returns a 1-based index (bit
+			 * 0 -> 1). We historically add +2 to compute
+			 * interrupt_num.
+			 *
+			 * Legacy mapping (kept for compatibility):
+			 *
+			 *   MSI #1 : link event (reserved)
+			 *   MSI #2 : unused (historical offset)
+			 *   MSI #3 : doorbell bit 0 (DB#0)
+			 *   MSI #4 : doorbell bit 1 (DB#1)
+			 *   ...
+			 *
+			 * Do not change this mapping to avoid breaking
+			 * interoperability with older peers.
+			 */
+			interrupt_num = ffs(db_bits) + 2;
+			db_bits &= db_bits - 1;
+
+			ret = pci_epc_raise_irq(epf->epc, func_no, vfunc_no,
+						PCI_IRQ_MSI, interrupt_num);
+			if (ret)
+				dev_err(&ntb->ntb.dev,
+					"Failed to raise IRQ for interrupt_num %u: %d\n",
+					interrupt_num, ret);
+		}
+	}
+
+	if (atomic64_read(&ntb->peer_db_pending))
+		queue_work(kpcintb_workqueue, &ntb->peer_db_work);
+}
+
 static int vntb_epf_peer_db_set(struct ntb_dev *ndev, u64 db_bits)
 {
-	u32 interrupt_num = ffs(db_bits) + 1;
 	struct epf_ntb *ntb = ntb_ndev(ndev);
-	u8 func_no, vfunc_no;
-	int ret;
-
-	func_no = ntb->epf->func_no;
-	vfunc_no = ntb->epf->vfunc_no;
 
 	/*
-	 * pci_epc_raise_irq() for MSI expects a 1-based interrupt number.
-	 * ffs() returns a 1-based index (bit 0 -> 1). interrupt_num has already
-	 * been computed as ffs(db_bits) + 1 above. Adding one more +1 when
-	 * calling pci_epc_raise_irq() therefore results in:
-	 *
-	 *   doorbell bit 0 -> MSI #3
-	 *
-	 * Legacy mapping (kept for compatibility):
-	 *
-	 *   MSI #1 : link event (reserved)
-	 *   MSI #2 : unused (historical offset)
-	 *   MSI #3 : doorbell bit 0 (DB#0)
-	 *   MSI #4 : doorbell bit 1 (DB#1)
-	 *   ...
-	 *
-	 * Do not change this mapping to avoid breaking interoperability with
-	 * older peers.
+	 * .peer_db_set() may be called from atomic context. pci_epc_raise_irq()
+	 * can sleep (it takes epc->lock), so defer MSI raising to process
+	 * context. Doorbell requests are coalesced in peer_db_pending.
 	 */
-	ret = pci_epc_raise_irq(ntb->epf->epc, func_no, vfunc_no,
-				PCI_IRQ_MSI, interrupt_num + 1);
-	if (ret)
-		dev_err(&ntb->ntb.dev, "Failed to raise IRQ\n");
+	atomic64_or(db_bits, &ntb->peer_db_pending);
+	queue_work(kpcintb_workqueue, &ntb->peer_db_work);
 
-	return ret;
+	return 0;
 }
 
 static u64 vntb_epf_db_read(struct ntb_dev *ndev)
@@ -1645,6 +1691,10 @@ static int epf_ntb_probe(struct pci_epf *epf,
 	ntb->epf = epf;
 	ntb->vbus_number = 0xff;
 
+	INIT_WORK(&ntb->peer_db_work, vntb_epf_peer_db_work);
+	disable_work(&ntb->peer_db_work);
+	atomic64_set(&ntb->peer_db_pending, 0);
+
 	/* Initially, no bar is assigned */
 	for (i = 0; i < VNTB_BAR_NUM; i++)
 		ntb->epf_ntb_bar[i] = NO_BAR;
-- 
2.51.0

On Fri, Feb 27, 2026 at 05:49:47PM +0900, Koichiro Den wrote:
> The NTB .peer_db_set() callback may be invoked from atomic context.
> pci-epf-vntb currently calls pci_epc_raise_irq() directly, but
> pci_epc_raise_irq() may sleep (it takes epc->lock).
>
> Avoid sleeping in atomic context by coalescing doorbell bits into an
> atomic64 pending mask and raising MSIs from a work item. Limit the
> amount of work per run to avoid monopolizing the workqueue under a
> doorbell storm.
>
> Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
> Signed-off-by: Koichiro Den <den@valinux.co.jp>
> ---
> Changes since v1:
>   - No functional changes.
>   - Updated comment in vntb_epf_peer_db_work().
>
>  drivers/pci/endpoint/functions/pci-epf-vntb.c | 106 +++++++++++++-----
>  1 file changed, 78 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> index 83372aba5106..e2c0b6dba793 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> @@ -69,6 +69,9 @@ static struct workqueue_struct *kpcintb_workqueue;
>  #define MAX_DB_COUNT			32
>  #define MAX_MW				4
>
> +/* Limit per-work execution to avoid monopolizing kworker on doorbell storms. */
> +#define VNTB_PEER_DB_WORK_BUDGET	5
> +
>  enum epf_ntb_bar {
>  	BAR_CONFIG,
>  	BAR_DB,
> @@ -129,6 +132,8 @@ struct epf_ntb {
>  	u32 spad_count;
>  	u64 mws_size[MAX_MW];
>  	atomic64_t db;
> +	atomic64_t peer_db_pending;
> +	struct work_struct peer_db_work;
>  	u32 vbus_number;
>  	u16 vntb_pid;
>  	u16 vntb_vid;
> @@ -933,6 +938,8 @@ static int epf_ntb_epc_init(struct epf_ntb *ntb)
>  	INIT_DELAYED_WORK(&ntb->cmd_handler, epf_ntb_cmd_handler);
>  	queue_work(kpcintb_workqueue, &ntb->cmd_handler.work);
>
> +	enable_work(&ntb->peer_db_work);
> +
>  	return 0;
>
>  err_write_header:
> @@ -955,6 +962,7 @@ static int epf_ntb_epc_init(struct epf_ntb *ntb)
>   */
>  static void epf_ntb_epc_cleanup(struct epf_ntb *ntb)
>  {
> +	disable_work_sync(&ntb->peer_db_work);
>  	epf_ntb_mw_bar_clear(ntb, ntb->num_mws);
>  	epf_ntb_db_bar_clear(ntb);
>  	epf_ntb_config_sspad_bar_clear(ntb);
> @@ -1369,41 +1377,79 @@ static int vntb_epf_peer_spad_write(struct ntb_dev *ndev, int pidx, int idx, u32
>  	return 0;
>  }
>
> +static void vntb_epf_peer_db_work(struct work_struct *work)
> +{
> +	struct epf_ntb *ntb = container_of(work, struct epf_ntb, peer_db_work);
> +	struct pci_epf *epf = ntb->epf;
> +	unsigned int budget = VNTB_PEER_DB_WORK_BUDGET;
> +	u8 func_no, vfunc_no;
> +	u32 interrupt_num;
> +	u64 db_bits;
> +	int ret;
> +
> +	if (!epf || !epf->epc)
> +		return;
> +
> +	func_no = epf->func_no;
> +	vfunc_no = epf->vfunc_no;
> +
> +	/*
> +	 * Drain doorbells from peer_db_pending in snapshots (atomic64_xchg()).
> +	 * Limit the number of snapshots handled per run so we don't monopolize
> +	 * the workqueue under a doorbell storm.
> +	 */
> +	while (budget--) {
> +		db_bits = atomic64_xchg(&ntb->peer_db_pending, 0);
> +		if (!db_bits)
> +			return;
> +
> +		while (db_bits) {
> +			/*
> +			 * pci_epc_raise_irq() for MSI expects a 1-based
> +			 * interrupt number. ffs() returns a 1-based index (bit
> +			 * 0 -> 1). We historically add +2 to compute
> +			 * interrupt_num.
> +			 *
> +			 * Legacy mapping (kept for compatibility):
> +			 *
> +			 *   MSI #1 : link event (reserved)
> +			 *   MSI #2 : unused (historical offset)
> +			 *   MSI #3 : doorbell bit 0 (DB#0)
> +			 *   MSI #4 : doorbell bit 1 (DB#1)
> +			 *   ...
> +			 *
> +			 * Do not change this mapping to avoid breaking
> +			 * interoperability with older peers.
> +			 */
> +			interrupt_num = ffs(db_bits) + 2;
> +			db_bits &= db_bits - 1;
> +
> +			ret = pci_epc_raise_irq(epf->epc, func_no, vfunc_no,
> +						PCI_IRQ_MSI, interrupt_num);
> +			if (ret)
> +				dev_err(&ntb->ntb.dev,
> +					"Failed to raise IRQ for interrupt_num %u: %d\n",
> +					interrupt_num, ret);
> +		}
> +	}
> +
> +	if (atomic64_read(&ntb->peer_db_pending))
> +		queue_work(kpcintb_workqueue, &ntb->peer_db_work);
> +}
> +
>  static int vntb_epf_peer_db_set(struct ntb_dev *ndev, u64 db_bits)
>  {
> -	u32 interrupt_num = ffs(db_bits) + 1;
>  	struct epf_ntb *ntb = ntb_ndev(ndev);
> -	u8 func_no, vfunc_no;
> -	int ret;
> -
> -	func_no = ntb->epf->func_no;
> -	vfunc_no = ntb->epf->vfunc_no;
>
>  	/*
> -	 * pci_epc_raise_irq() for MSI expects a 1-based interrupt number.
> -	 * ffs() returns a 1-based index (bit 0 -> 1). interrupt_num has already
> -	 * been computed as ffs(db_bits) + 1 above. Adding one more +1 when
> -	 * calling pci_epc_raise_irq() therefore results in:
> -	 *
> -	 *   doorbell bit 0 -> MSI #3
> -	 *
> -	 * Legacy mapping (kept for compatibility):
> -	 *
> -	 *   MSI #1 : link event (reserved)
> -	 *   MSI #2 : unused (historical offset)
> -	 *   MSI #3 : doorbell bit 0 (DB#0)
> -	 *   MSI #4 : doorbell bit 1 (DB#1)
> -	 *   ...
> -	 *
> -	 * Do not change this mapping to avoid breaking interoperability with
> -	 * older peers.
> +	 * .peer_db_set() may be called from atomic context. pci_epc_raise_irq()
> +	 * can sleep (it takes epc->lock), so defer MSI raising to process
> +	 * context. Doorbell requests are coalesced in peer_db_pending.
>  	 */
> -	ret = pci_epc_raise_irq(ntb->epf->epc, func_no, vfunc_no,
> -				PCI_IRQ_MSI, interrupt_num + 1);
> -	if (ret)
> -		dev_err(&ntb->ntb.dev, "Failed to raise IRQ\n");
> +	atomic64_or(db_bits, &ntb->peer_db_pending);
> +	queue_work(kpcintb_workqueue, &ntb->peer_db_work);
>
> -	return ret;
> +	return 0;
>  }
>
>  static u64 vntb_epf_db_read(struct ntb_dev *ndev)
> @@ -1645,6 +1691,10 @@ static int epf_ntb_probe(struct pci_epf *epf,
>  	ntb->epf = epf;
>  	ntb->vbus_number = 0xff;
>
> +	INIT_WORK(&ntb->peer_db_work, vntb_epf_peer_db_work);
> +	disable_work(&ntb->peer_db_work);
> +	atomic64_set(&ntb->peer_db_pending, 0);
> +

Does it need call disable_work_sync() in unbind or remove() function?

Frank

>  	/* Initially, no bar is assigned */
>  	for (i = 0; i < VNTB_BAR_NUM; i++)
>  		ntb->epf_ntb_bar[i] = NO_BAR;
> --
> 2.51.0
>

On Fri, Feb 27, 2026 at 10:49:28AM -0500, Frank Li wrote:
> On Fri, Feb 27, 2026 at 05:49:47PM +0900, Koichiro Den wrote:
> > The NTB .peer_db_set() callback may be invoked from atomic context.
> > pci-epf-vntb currently calls pci_epc_raise_irq() directly, but
> > pci_epc_raise_irq() may sleep (it takes epc->lock).
> >
> > Avoid sleeping in atomic context by coalescing doorbell bits into an
> > atomic64 pending mask and raising MSIs from a work item. Limit the
> > amount of work per run to avoid monopolizing the workqueue under a
> > doorbell storm.
> >
> > Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
> > Signed-off-by: Koichiro Den <den@valinux.co.jp>
> > ---
> > Changes since v1:
> >   - No functional changes.
> >   - Updated comment in vntb_epf_peer_db_work().
> >
> >  drivers/pci/endpoint/functions/pci-epf-vntb.c | 106 +++++++++++++-----
> >  1 file changed, 78 insertions(+), 28 deletions(-)
> >
> > diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> > index 83372aba5106..e2c0b6dba793 100644
> > --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
> > +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> > @@ -69,6 +69,9 @@ static struct workqueue_struct *kpcintb_workqueue;
> >  #define MAX_DB_COUNT			32
> >  #define MAX_MW				4
> >
> > +/* Limit per-work execution to avoid monopolizing kworker on doorbell storms. */
> > +#define VNTB_PEER_DB_WORK_BUDGET	5
> > +
> >  enum epf_ntb_bar {
> >  	BAR_CONFIG,
> >  	BAR_DB,
> > @@ -129,6 +132,8 @@ struct epf_ntb {
> >  	u32 spad_count;
> >  	u64 mws_size[MAX_MW];
> >  	atomic64_t db;
> > +	atomic64_t peer_db_pending;
> > +	struct work_struct peer_db_work;
> >  	u32 vbus_number;
> >  	u16 vntb_pid;
> >  	u16 vntb_vid;
> > @@ -933,6 +938,8 @@ static int epf_ntb_epc_init(struct epf_ntb *ntb)
> >  	INIT_DELAYED_WORK(&ntb->cmd_handler, epf_ntb_cmd_handler);
> >  	queue_work(kpcintb_workqueue, &ntb->cmd_handler.work);
> >
> > +	enable_work(&ntb->peer_db_work);
> > +
> >  	return 0;
> >
> >  err_write_header:
> > @@ -955,6 +962,7 @@ static int epf_ntb_epc_init(struct epf_ntb *ntb)
> >   */
> >  static void epf_ntb_epc_cleanup(struct epf_ntb *ntb)
> >  {
> > +	disable_work_sync(&ntb->peer_db_work);
> >  	epf_ntb_mw_bar_clear(ntb, ntb->num_mws);
> >  	epf_ntb_db_bar_clear(ntb);
> >  	epf_ntb_config_sspad_bar_clear(ntb);
> > @@ -1369,41 +1377,79 @@ static int vntb_epf_peer_spad_write(struct ntb_dev *ndev, int pidx, int idx, u32
> >  	return 0;
> >  }
> >
> > +static void vntb_epf_peer_db_work(struct work_struct *work)
> > +{
> > +	struct epf_ntb *ntb = container_of(work, struct epf_ntb, peer_db_work);
> > +	struct pci_epf *epf = ntb->epf;
> > +	unsigned int budget = VNTB_PEER_DB_WORK_BUDGET;
> > +	u8 func_no, vfunc_no;
> > +	u32 interrupt_num;
> > +	u64 db_bits;
> > +	int ret;
> > +
> > +	if (!epf || !epf->epc)
> > +		return;
> > +
> > +	func_no = epf->func_no;
> > +	vfunc_no = epf->vfunc_no;
> > +
> > +	/*
> > +	 * Drain doorbells from peer_db_pending in snapshots (atomic64_xchg()).
> > +	 * Limit the number of snapshots handled per run so we don't monopolize
> > +	 * the workqueue under a doorbell storm.
> > +	 */
> > +	while (budget--) {
> > +		db_bits = atomic64_xchg(&ntb->peer_db_pending, 0);
> > +		if (!db_bits)
> > +			return;
> > +
> > +		while (db_bits) {
> > +			/*
> > +			 * pci_epc_raise_irq() for MSI expects a 1-based
> > +			 * interrupt number. ffs() returns a 1-based index (bit
> > +			 * 0 -> 1). We historically add +2 to compute
> > +			 * interrupt_num.
> > +			 *
> > +			 * Legacy mapping (kept for compatibility):
> > +			 *
> > +			 *   MSI #1 : link event (reserved)
> > +			 *   MSI #2 : unused (historical offset)
> > +			 *   MSI #3 : doorbell bit 0 (DB#0)
> > +			 *   MSI #4 : doorbell bit 1 (DB#1)
> > +			 *   ...
> > +			 *
> > +			 * Do not change this mapping to avoid breaking
> > +			 * interoperability with older peers.
> > +			 */
> > +			interrupt_num = ffs(db_bits) + 2;
> > +			db_bits &= db_bits - 1;
> > +
> > +			ret = pci_epc_raise_irq(epf->epc, func_no, vfunc_no,
> > +						PCI_IRQ_MSI, interrupt_num);
> > +			if (ret)
> > +				dev_err(&ntb->ntb.dev,
> > +					"Failed to raise IRQ for interrupt_num %u: %d\n",
> > +					interrupt_num, ret);
> > +		}
> > +	}
> > +
> > +	if (atomic64_read(&ntb->peer_db_pending))
> > +		queue_work(kpcintb_workqueue, &ntb->peer_db_work);
> > +}
> > +
> >  static int vntb_epf_peer_db_set(struct ntb_dev *ndev, u64 db_bits)
> >  {
> > -	u32 interrupt_num = ffs(db_bits) + 1;
> >  	struct epf_ntb *ntb = ntb_ndev(ndev);
> > -	u8 func_no, vfunc_no;
> > -	int ret;
> > -
> > -	func_no = ntb->epf->func_no;
> > -	vfunc_no = ntb->epf->vfunc_no;
> >
> >  	/*
> > -	 * pci_epc_raise_irq() for MSI expects a 1-based interrupt number.
> > -	 * ffs() returns a 1-based index (bit 0 -> 1). interrupt_num has already
> > -	 * been computed as ffs(db_bits) + 1 above. Adding one more +1 when
> > -	 * calling pci_epc_raise_irq() therefore results in:
> > -	 *
> > -	 *   doorbell bit 0 -> MSI #3
> > -	 *
> > -	 * Legacy mapping (kept for compatibility):
> > -	 *
> > -	 *   MSI #1 : link event (reserved)
> > -	 *   MSI #2 : unused (historical offset)
> > -	 *   MSI #3 : doorbell bit 0 (DB#0)
> > -	 *   MSI #4 : doorbell bit 1 (DB#1)
> > -	 *   ...
> > -	 *
> > -	 * Do not change this mapping to avoid breaking interoperability with
> > -	 * older peers.
> > +	 * .peer_db_set() may be called from atomic context. pci_epc_raise_irq()
> > +	 * can sleep (it takes epc->lock), so defer MSI raising to process
> > +	 * context. Doorbell requests are coalesced in peer_db_pending.
> >  	 */
> > -	ret = pci_epc_raise_irq(ntb->epf->epc, func_no, vfunc_no,
> > -				PCI_IRQ_MSI, interrupt_num + 1);
> > -	if (ret)
> > -		dev_err(&ntb->ntb.dev, "Failed to raise IRQ\n");
> > +	atomic64_or(db_bits, &ntb->peer_db_pending);
> > +	queue_work(kpcintb_workqueue, &ntb->peer_db_work);
> >
> > -	return ret;
> > +	return 0;
> >  }
> >
> >  static u64 vntb_epf_db_read(struct ntb_dev *ndev)
> > @@ -1645,6 +1691,10 @@ static int epf_ntb_probe(struct pci_epf *epf,
> >  	ntb->epf = epf;
> >  	ntb->vbus_number = 0xff;
> >
> > +	INIT_WORK(&ntb->peer_db_work, vntb_epf_peer_db_work);
> > +	disable_work(&ntb->peer_db_work);
> > +	atomic64_set(&ntb->peer_db_pending, 0);
> > +
> 
> Does it need call disable_work_sync() in unbind or remove() function?

This patch (2/10) handles it. Please see the changes in epf_ntb_epc_cleanup().

Thanks,
Koichiro

> 
> Frank
> 
> >  	/* Initially, no bar is assigned */
> >  	for (i = 0; i < VNTB_BAR_NUM; i++)
> >  		ntb->epf_ntb_bar[i] = NO_BAR;
> > --
> > 2.51.0
> >