RE: [PATCH 1/3] blk-mq: Allow PCI vector offset for mapping queues

2018-03-28 Thread Don Brace 
> -Original Message-
> From: linux-scsi-ow...@vger.kernel.org [mailto:linux-scsi-
> ow...@vger.kernel.org] On Behalf Of Keith Busch
> Sent: Tuesday, March 27, 2018 10:39 AM
> To: Linux NVMe <linux-n...@lists.infradead.org>; Linux Block  bl...@vger.kernel.org>
> Cc: Christoph Hellwig <h...@lst.de>; Sagi Grimberg <s...@grimberg.me>;
> Jianchao Wang <jianchao.w.w...@oracle.com>; Ming Lei
> <ming@redhat.com>; Jens Axboe <ax...@kernel.dk>; Keith Busch
> <keith.bu...@intel.com>; Don Brace <don.br...@microsemi.com>; qla2xxx-
> upstr...@qlogic.com; linux-s...@vger.kernel.org
> Subject: [PATCH 1/3] blk-mq: Allow PCI vector offset for mapping queues
> 
> EXTERNAL EMAIL
> 
> 
> The PCI interrupt vectors intended to be associated with a queue may
> not start at 0; a driver may allocate pre_vectors for special use. This
> patch adds an offset parameter so blk-mq may find the intended affinity
> mask and updates all drivers using this API accordingly.
> 
> Cc: Don Brace <don.br...@microsemi.com>
> Cc: <qla2xxx-upstr...@qlogic.com>
> Cc: <linux-s...@vger.kernel.org>
> Signed-off-by: Keith Busch <keith.bu...@intel.com>
> ---
> v1 -> v2:
> 
>   Update blk-mq API directly instead of chaining a default parameter to
>   a new API, and update all drivers accordingly.
> 
>  block/blk-mq-pci.c| 6 --
>  drivers/nvme/host/pci.c   | 2 +-
>  drivers/scsi/qla2xxx/qla_os.c | 2 +-
>  drivers/scsi/smartpqi/smartpqi_init.c | 2 +-
>  include/linux/blk-mq-pci.h| 3 ++-
>  5 files changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/scsi/smartpqi/smartpqi_init.c
> b/drivers/scsi/smartpqi/smartpqi_init.c
> index b2880c7709e6..10c94011c8a8 100644
> --- a/drivers/scsi/smartpqi/smartpqi_init.c
> +++ b/drivers/scsi/smartpqi/smartpqi_init.c
> @@ -5348,7 +5348,7 @@ static int pqi_map_queues(struct Scsi_Host *shost)
>  {
> struct pqi_ctrl_info *ctrl_info = shost_to_hba(shost);
> 
> -   return blk_mq_pci_map_queues(>tag_set, ctrl_info->pci_dev);
> +   return blk_mq_pci_map_queues(>tag_set, ctrl_info->pci_dev, 0);
>  }
> 

Acked-by: Don Brace <don.br...@microsemi.com>

Re: [PATCH 1/3] blk-mq: Allow PCI vector offset for mapping queues

2018-03-27 Thread Jens Axboe 
On 3/27/18 9:39 AM, Keith Busch wrote:
> The PCI interrupt vectors intended to be associated with a queue may
> not start at 0; a driver may allocate pre_vectors for special use. This
> patch adds an offset parameter so blk-mq may find the intended affinity
> mask and updates all drivers using this API accordingly.

Looks good to me, I'll queue it up for 4.17.

-- 
Jens Axboe

Re: [PATCH 1/3] blk-mq: Allow PCI vector offset for mapping queues

2018-03-27 Thread Ming Lei 
On Tue, Mar 27, 2018 at 09:39:06AM -0600, Keith Busch wrote:
> The PCI interrupt vectors intended to be associated with a queue may
> not start at 0; a driver may allocate pre_vectors for special use. This
> patch adds an offset parameter so blk-mq may find the intended affinity
> mask and updates all drivers using this API accordingly.
> 
> Cc: Don Brace 
> Cc: 
> Cc: 
> Signed-off-by: Keith Busch 
> ---
> v1 -> v2:
> 
>   Update blk-mq API directly instead of chaining a default parameter to
>   a new API, and update all drivers accordingly.
> 
>  block/blk-mq-pci.c| 6 --
>  drivers/nvme/host/pci.c   | 2 +-
>  drivers/scsi/qla2xxx/qla_os.c | 2 +-
>  drivers/scsi/smartpqi/smartpqi_init.c | 2 +-
>  include/linux/blk-mq-pci.h| 3 ++-
>  5 files changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/block/blk-mq-pci.c b/block/blk-mq-pci.c
> index 76944e3271bf..e233996bb76f 100644
> --- a/block/blk-mq-pci.c
> +++ b/block/blk-mq-pci.c
> @@ -21,6 +21,7 @@
>   * blk_mq_pci_map_queues - provide a default queue mapping for PCI device
>   * @set: tagset to provide the mapping for
>   * @pdev:PCI device associated with @set.
> + * @offset:  Offset to use for the pci irq vector
>   *
>   * This function assumes the PCI device @pdev has at least as many available
>   * interrupt vectors as @set has queues.  It will then query the vector
> @@ -28,13 +29,14 @@
>   * that maps a queue to the CPUs that have irq affinity for the corresponding
>   * vector.
>   */
> -int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev)
> +int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev,
> + int offset)
>  {
>   const struct cpumask *mask;
>   unsigned int queue, cpu;
>  
>   for (queue = 0; queue < set->nr_hw_queues; queue++) {
> - mask = pci_irq_get_affinity(pdev, queue);
> + mask = pci_irq_get_affinity(pdev, queue + offset);
>   if (!mask)
>   goto fallback;
>  
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index cef5ce851a92..e3b9efca0571 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -414,7 +414,7 @@ static int nvme_pci_map_queues(struct blk_mq_tag_set *set)
>  {
>   struct nvme_dev *dev = set->driver_data;
>  
> - return blk_mq_pci_map_queues(set, to_pci_dev(dev->dev));
> + return blk_mq_pci_map_queues(set, to_pci_dev(dev->dev), 0);
>  }
>  
>  /**
> diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
> index 12ee6e02d146..2c705f3dd265 100644
> --- a/drivers/scsi/qla2xxx/qla_os.c
> +++ b/drivers/scsi/qla2xxx/qla_os.c
> @@ -6805,7 +6805,7 @@ static int qla2xxx_map_queues(struct Scsi_Host *shost)
>   if (USER_CTRL_IRQ(vha->hw))
>   rc = blk_mq_map_queues(>tag_set);
>   else
> - rc = blk_mq_pci_map_queues(>tag_set, vha->hw->pdev);
> + rc = blk_mq_pci_map_queues(>tag_set, vha->hw->pdev, 0);
>   return rc;
>  }
>  
> diff --git a/drivers/scsi/smartpqi/smartpqi_init.c 
> b/drivers/scsi/smartpqi/smartpqi_init.c
> index b2880c7709e6..10c94011c8a8 100644
> --- a/drivers/scsi/smartpqi/smartpqi_init.c
> +++ b/drivers/scsi/smartpqi/smartpqi_init.c
> @@ -5348,7 +5348,7 @@ static int pqi_map_queues(struct Scsi_Host *shost)
>  {
>   struct pqi_ctrl_info *ctrl_info = shost_to_hba(shost);
>  
> - return blk_mq_pci_map_queues(>tag_set, ctrl_info->pci_dev);
> + return blk_mq_pci_map_queues(>tag_set, ctrl_info->pci_dev, 0);
>  }
>  
>  static int pqi_getpciinfo_ioctl(struct pqi_ctrl_info *ctrl_info,
> diff --git a/include/linux/blk-mq-pci.h b/include/linux/blk-mq-pci.h
> index 6338551e0fb9..9f4c17f0d2d8 100644
> --- a/include/linux/blk-mq-pci.h
> +++ b/include/linux/blk-mq-pci.h
> @@ -5,6 +5,7 @@
>  struct blk_mq_tag_set;
>  struct pci_dev;
>  
> -int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev);
> +int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev,
> +   int offset);
>  
>  #endif /* _LINUX_BLK_MQ_PCI_H */
> -- 
> 2.14.3
> 

Reviewed-by: Ming Lei 

-- 
Ming

[PATCH 1/3] blk-mq: Allow PCI vector offset for mapping queues

2018-03-27 Thread Keith Busch 
The PCI interrupt vectors intended to be associated with a queue may
not start at 0; a driver may allocate pre_vectors for special use. This
patch adds an offset parameter so blk-mq may find the intended affinity
mask and updates all drivers using this API accordingly.

Cc: Don Brace 
Cc: 
Cc: 
Signed-off-by: Keith Busch 
---
v1 -> v2:

  Update blk-mq API directly instead of chaining a default parameter to
  a new API, and update all drivers accordingly.

 block/blk-mq-pci.c| 6 --
 drivers/nvme/host/pci.c   | 2 +-
 drivers/scsi/qla2xxx/qla_os.c | 2 +-
 drivers/scsi/smartpqi/smartpqi_init.c | 2 +-
 include/linux/blk-mq-pci.h| 3 ++-
 5 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/block/blk-mq-pci.c b/block/blk-mq-pci.c
index 76944e3271bf..e233996bb76f 100644
--- a/block/blk-mq-pci.c
+++ b/block/blk-mq-pci.c
@@ -21,6 +21,7 @@
  * blk_mq_pci_map_queues - provide a default queue mapping for PCI device
  * @set:   tagset to provide the mapping for
  * @pdev:  PCI device associated with @set.
+ * @offset:Offset to use for the pci irq vector
  *
  * This function assumes the PCI device @pdev has at least as many available
  * interrupt vectors as @set has queues.  It will then query the vector
@@ -28,13 +29,14 @@
  * that maps a queue to the CPUs that have irq affinity for the corresponding
  * vector.
  */
-int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev)
+int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev,
+   int offset)
 {
const struct cpumask *mask;
unsigned int queue, cpu;
 
for (queue = 0; queue < set->nr_hw_queues; queue++) {
-   mask = pci_irq_get_affinity(pdev, queue);
+   mask = pci_irq_get_affinity(pdev, queue + offset);
if (!mask)
goto fallback;
 
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index cef5ce851a92..e3b9efca0571 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -414,7 +414,7 @@ static int nvme_pci_map_queues(struct blk_mq_tag_set *set)
 {
struct nvme_dev *dev = set->driver_data;
 
-   return blk_mq_pci_map_queues(set, to_pci_dev(dev->dev));
+   return blk_mq_pci_map_queues(set, to_pci_dev(dev->dev), 0);
 }
 
 /**
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 12ee6e02d146..2c705f3dd265 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -6805,7 +6805,7 @@ static int qla2xxx_map_queues(struct Scsi_Host *shost)
if (USER_CTRL_IRQ(vha->hw))
rc = blk_mq_map_queues(>tag_set);
else
-   rc = blk_mq_pci_map_queues(>tag_set, vha->hw->pdev);
+   rc = blk_mq_pci_map_queues(>tag_set, vha->hw->pdev, 0);
return rc;
 }
 
diff --git a/drivers/scsi/smartpqi/smartpqi_init.c 
b/drivers/scsi/smartpqi/smartpqi_init.c
index b2880c7709e6..10c94011c8a8 100644
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -5348,7 +5348,7 @@ static int pqi_map_queues(struct Scsi_Host *shost)
 {
struct pqi_ctrl_info *ctrl_info = shost_to_hba(shost);
 
-   return blk_mq_pci_map_queues(>tag_set, ctrl_info->pci_dev);
+   return blk_mq_pci_map_queues(>tag_set, ctrl_info->pci_dev, 0);
 }
 
 static int pqi_getpciinfo_ioctl(struct pqi_ctrl_info *ctrl_info,
diff --git a/include/linux/blk-mq-pci.h b/include/linux/blk-mq-pci.h
index 6338551e0fb9..9f4c17f0d2d8 100644
--- a/include/linux/blk-mq-pci.h
+++ b/include/linux/blk-mq-pci.h
@@ -5,6 +5,7 @@
 struct blk_mq_tag_set;
 struct pci_dev;
 
-int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev);
+int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev,
+ int offset);
 
 #endif /* _LINUX_BLK_MQ_PCI_H */
-- 
2.14.3

Re: [PATCH 1/3] blk-mq: Allow PCI vector offset for mapping queues

2018-03-27 Thread Christoph Hellwig 
On Fri, Mar 23, 2018 at 04:19:21PM -0600, Keith Busch wrote:
> The PCI interrupt vectors intended to be associated with a queue may
> not start at 0. This patch adds an offset parameter so blk-mq may find
> the intended affinity mask. The default value is 0 so existing drivers
> that don't care about this parameter don't need to change.
> 
> Signed-off-by: Keith Busch 
> ---
>  block/blk-mq-pci.c | 12 ++--
>  include/linux/blk-mq-pci.h |  2 ++
>  2 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/block/blk-mq-pci.c b/block/blk-mq-pci.c
> index 76944e3271bf..1040a7705c13 100644
> --- a/block/blk-mq-pci.c
> +++ b/block/blk-mq-pci.c
> @@ -21,6 +21,7 @@
>   * blk_mq_pci_map_queues - provide a default queue mapping for PCI device
>   * @set: tagset to provide the mapping for
>   * @pdev:PCI device associated with @set.
> + * @offset:  PCI irq starting vector offset
>   *
>   * This function assumes the PCI device @pdev has at least as many available
>   * interrupt vectors as @set has queues.  It will then query the vector
> @@ -28,13 +29,14 @@
>   * that maps a queue to the CPUs that have irq affinity for the corresponding
>   * vector.
>   */
> -int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev)
> +int __blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev,
> + int offset)

Can you just change the blk_mq_pci_map_queues prototype instead?

Re: [PATCH 1/3] blk-mq: Allow PCI vector offset for mapping queues

2018-03-26 Thread Keith Busch 
On Mon, Mar 26, 2018 at 09:50:38AM +0800, Ming Lei wrote:
> 
> Given no many callers of blk_mq_pci_map_queues(), I suggest to add the
> parameter of 'offset' to this API directly, then people may keep the 
> '.pre_vectors' stuff in mind, and avoid to misuse it.

Yeah, I think I have to agree. I was trying really hard to not touch
other drivers, but the concept doesn't seem odd enough to justify hiding
it behind a default parameter. I'll send v2 tomorrow if there's no other
feedback.

Re: [PATCH 1/3] blk-mq: Allow PCI vector offset for mapping queues

2018-03-26 Thread Keith Busch 
On Sat, Mar 24, 2018 at 09:55:49PM +0800, jianchao.wang wrote:
> Maybe we could provide a callback parameter for __blk_mq_pci_map_queues which
> give the mapping from hctx queue num to device-relative interrupt vector 
> index.

If a driver's mapping is so complicated as to require a special per-hctx
callback, it'd be just as easy to implement the mapping in that driver's
blk_mq_ops' 'map_queues' directly.

Re: [PATCH 1/3] blk-mq: Allow PCI vector offset for mapping queues

2018-03-25 Thread Ming Lei 
On Fri, Mar 23, 2018 at 04:19:21PM -0600, Keith Busch wrote:
> The PCI interrupt vectors intended to be associated with a queue may
> not start at 0. This patch adds an offset parameter so blk-mq may find
> the intended affinity mask. The default value is 0 so existing drivers
> that don't care about this parameter don't need to change.
> 
> Signed-off-by: Keith Busch 
> ---
>  block/blk-mq-pci.c | 12 ++--
>  include/linux/blk-mq-pci.h |  2 ++
>  2 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/block/blk-mq-pci.c b/block/blk-mq-pci.c
> index 76944e3271bf..1040a7705c13 100644
> --- a/block/blk-mq-pci.c
> +++ b/block/blk-mq-pci.c
> @@ -21,6 +21,7 @@
>   * blk_mq_pci_map_queues - provide a default queue mapping for PCI device
>   * @set: tagset to provide the mapping for
>   * @pdev:PCI device associated with @set.
> + * @offset:  PCI irq starting vector offset
>   *
>   * This function assumes the PCI device @pdev has at least as many available
>   * interrupt vectors as @set has queues.  It will then query the vector
> @@ -28,13 +29,14 @@
>   * that maps a queue to the CPUs that have irq affinity for the corresponding
>   * vector.
>   */
> -int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev)
> +int __blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev,
> + int offset)
>  {
>   const struct cpumask *mask;
>   unsigned int queue, cpu;
>  
>   for (queue = 0; queue < set->nr_hw_queues; queue++) {
> - mask = pci_irq_get_affinity(pdev, queue);
> + mask = pci_irq_get_affinity(pdev, queue + offset);
>   if (!mask)
>   goto fallback;
>  
> @@ -50,4 +52,10 @@ int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, 
> struct pci_dev *pdev)
>   set->mq_map[cpu] = 0;
>   return 0;
>  }
> +EXPORT_SYMBOL_GPL(__blk_mq_pci_map_queues);
> +
> +int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev)
> +{
> + return __blk_mq_pci_map_queues(set, pdev, 0);
> +}
>  EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues);
> diff --git a/include/linux/blk-mq-pci.h b/include/linux/blk-mq-pci.h
> index 6338551e0fb9..5a92ecdbd78e 100644
> --- a/include/linux/blk-mq-pci.h
> +++ b/include/linux/blk-mq-pci.h
> @@ -5,6 +5,8 @@
>  struct blk_mq_tag_set;
>  struct pci_dev;
>  
> +int __blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev,
> + int offset);
>  int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev);
>  
>  #endif /* _LINUX_BLK_MQ_PCI_H */
> -- 
> 2.14.3
> 

Given no many callers of blk_mq_pci_map_queues(), I suggest to add the
parameter of 'offset' to this API directly, then people may keep the 
'.pre_vectors' stuff in mind, and avoid to misuse it.

Thanks,
Ming

Re: [PATCH 1/3] blk-mq: Allow PCI vector offset for mapping queues

2018-03-24 Thread jianchao.wang 
Hi Keith

Thanks for your time and patch for this.

On 03/24/2018 06:19 AM, Keith Busch wrote:
> The PCI interrupt vectors intended to be associated with a queue may
> not start at 0. This patch adds an offset parameter so blk-mq may find
> the intended affinity mask. The default value is 0 so existing drivers
> that don't care about this parameter don't need to change.
> 
> Signed-off-by: Keith Busch 
> ---
>  block/blk-mq-pci.c | 12 ++--
>  include/linux/blk-mq-pci.h |  2 ++
>  2 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/block/blk-mq-pci.c b/block/blk-mq-pci.c
> index 76944e3271bf..1040a7705c13 100644
> --- a/block/blk-mq-pci.c
> +++ b/block/blk-mq-pci.c
> @@ -21,6 +21,7 @@
>   * blk_mq_pci_map_queues - provide a default queue mapping for PCI device
>   * @set: tagset to provide the mapping for
>   * @pdev:PCI device associated with @set.
> + * @offset:  PCI irq starting vector offset
>   *
>   * This function assumes the PCI device @pdev has at least as many available
>   * interrupt vectors as @set has queues.  It will then query the vector
> @@ -28,13 +29,14 @@
>   * that maps a queue to the CPUs that have irq affinity for the corresponding
>   * vector.
>   */
> -int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev)
> +int __blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev,
> + int offset)
>  {
>   const struct cpumask *mask;
>   unsigned int queue, cpu;
>  
>   for (queue = 0; queue < set->nr_hw_queues; queue++) {
> - mask = pci_irq_get_affinity(pdev, queue);
> + mask = pci_irq_get_affinity(pdev, queue + offset);
>   if (!mask)
>   goto fallback;
>  

Maybe we could provide a callback parameter for __blk_mq_pci_map_queues which
give the mapping from hctx queue num to device-relative interrupt vector index.

Thanks
Jianchao

[PATCH 1/3] blk-mq: Allow PCI vector offset for mapping queues

2018-03-23 Thread Keith Busch 
The PCI interrupt vectors intended to be associated with a queue may
not start at 0. This patch adds an offset parameter so blk-mq may find
the intended affinity mask. The default value is 0 so existing drivers
that don't care about this parameter don't need to change.

Signed-off-by: Keith Busch 
---
 block/blk-mq-pci.c | 12 ++--
 include/linux/blk-mq-pci.h |  2 ++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/block/blk-mq-pci.c b/block/blk-mq-pci.c
index 76944e3271bf..1040a7705c13 100644
--- a/block/blk-mq-pci.c
+++ b/block/blk-mq-pci.c
@@ -21,6 +21,7 @@
  * blk_mq_pci_map_queues - provide a default queue mapping for PCI device
  * @set:   tagset to provide the mapping for
  * @pdev:  PCI device associated with @set.
+ * @offset:PCI irq starting vector offset
  *
  * This function assumes the PCI device @pdev has at least as many available
  * interrupt vectors as @set has queues.  It will then query the vector
@@ -28,13 +29,14 @@
  * that maps a queue to the CPUs that have irq affinity for the corresponding
  * vector.
  */
-int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev)
+int __blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev,
+   int offset)
 {
const struct cpumask *mask;
unsigned int queue, cpu;
 
for (queue = 0; queue < set->nr_hw_queues; queue++) {
-   mask = pci_irq_get_affinity(pdev, queue);
+   mask = pci_irq_get_affinity(pdev, queue + offset);
if (!mask)
goto fallback;
 
@@ -50,4 +52,10 @@ int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct 
pci_dev *pdev)
set->mq_map[cpu] = 0;
return 0;
 }
+EXPORT_SYMBOL_GPL(__blk_mq_pci_map_queues);
+
+int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev)
+{
+   return __blk_mq_pci_map_queues(set, pdev, 0);
+}
 EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues);
diff --git a/include/linux/blk-mq-pci.h b/include/linux/blk-mq-pci.h
index 6338551e0fb9..5a92ecdbd78e 100644
--- a/include/linux/blk-mq-pci.h
+++ b/include/linux/blk-mq-pci.h
@@ -5,6 +5,8 @@
 struct blk_mq_tag_set;
 struct pci_dev;
 
+int __blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev,
+   int offset);
 int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev);
 
 #endif /* _LINUX_BLK_MQ_PCI_H */
-- 
2.14.3