diff mbox

PCI/MSI: Only disable affinity settings if pre and post vector count is equal to max_vecs and not min_vecs

Message ID 1487883699-3528-1-git-send-email-himanshu.madhani@cavium.com
State Superseded
Headers show

Commit Message

Madhani, Himanshu Feb. 23, 2017, 9:01 p.m. UTC 
From: Michael Hernandez <michael.hernandez@cavium.com>

min_vecs is the minimum amount of vectors needed to operate in MSI-X mode
which may just include the vectors that don't need affinity.

Disabling affinity settings causes the qla2xxx driver scsi_add_host
to fail when blk_mq is enabled as the blk_mq_pci_map_queues expects
affinity masks on each vector.

v1 --> v2

o Moved the check from pci_alloc_irq_vectors_affinity() to
  __pci_enable_{msi|msix}_range()

Fixes: dfef358 ("PCI/MSI: Don't apply affinity if there aren't enough vectors left")
Signed-off-by: Michael Hernandez <michael.hernandez@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
---
 drivers/pci/msi.c |   32 ++++++++++++++++++++++----------
 1 files changed, 22 insertions(+), 10 deletions(-)

Comments

Madhani, Himanshu Feb. 28, 2017, 10:05 p.m. UTC | #1 
Hi Christoph, Bjorn, 

Does this updated patch looks good. Please review. 

Thanks,
Himanshu


> -----Original Message-----
> From: Himanshu Madhani [mailto:himanshu.madhani@cavium.com]
> Sent: Thursday, February 23, 2017 1:02 PM
> To: bhelgaas@google.com; linux-pci@vger.kernel.org; hch@lst.de
> Cc: Madhani, Himanshu <Himanshu.Madhani@cavium.com>
> Subject: [PATCH] PCI/MSI: Only disable affinity settings if pre and post vector
> count is equal to max_vecs and not min_vecs
> 
> From: Michael Hernandez <michael.hernandez@cavium.com>
> 
> min_vecs is the minimum amount of vectors needed to operate in MSI-X
> mode which may just include the vectors that don't need affinity.
> 
> Disabling affinity settings causes the qla2xxx driver scsi_add_host to fail
> when blk_mq is enabled as the blk_mq_pci_map_queues expects affinity
> masks on each vector.
> 
> v1 --> v2
> 
> o Moved the check from pci_alloc_irq_vectors_affinity() to
>   __pci_enable_{msi|msix}_range()
> 
> Fixes: dfef358 ("PCI/MSI: Don't apply affinity if there aren't enough vectors
> left")
> Signed-off-by: Michael Hernandez <michael.hernandez@cavium.com>
> Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: stable@vger.kernel.org
> ---
>  drivers/pci/msi.c |   32 ++++++++++++++++++++++----------
>  1 files changed, 22 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 7f73bac..c61039b
> 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -1091,6 +1091,17 @@ static int __pci_enable_msi_range(struct pci_dev
> *dev, int minvec, int maxvec,
> 
>  	for (;;) {
>  		if (affd) {
> +			if (affd->pre_vectors + affd->post_vectors > nvec)
> +				return -EINVAL;
> +			/*
> +			 * If there aren't any vectors left after applying the
> +			 * pre/post vectors don't bother with assigning
> +			 * affinity.
> +			 */
> +			if (affd->pre_vectors + affd->post_vectors == nvec)
> +				affd = NULL;
> +		}
> +		if (affd) {
>  			nvec = irq_calc_affinity_vectors(nvec, affd);
>  			if (nvec < minvec)
>  				return -ENOSPC;
> @@ -1138,6 +1149,17 @@ static int __pci_enable_msix_range(struct pci_dev
> *dev,
> 
>  	for (;;) {
>  		if (affd) {
> +			if (affd->pre_vectors + affd->post_vectors > nvec)
> +				return -EINVAL;
> +			/*
> +			 * If there aren't any vectors left after applying the
> +			 * pre/post vectors don't bother with assigning
> +			 * affinity.
> +			 */
> +			if (affd->pre_vectors + affd->post_vectors == nvec)
> +				affd = NULL;
> +		}
> +		if (affd) {
>  			nvec = irq_calc_affinity_vectors(nvec, affd);
>  			if (nvec < minvec)
>  				return -ENOSPC;
> @@ -1206,16 +1228,6 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev
> *dev, unsigned int min_vecs,
>  	if (flags & PCI_IRQ_AFFINITY) {
>  		if (!affd)
>  			affd = &msi_default_affd;
> -
> -		if (affd->pre_vectors + affd->post_vectors > min_vecs)
> -			return -EINVAL;
> -
> -		/*
> -		 * If there aren't any vectors left after applying the pre/post
> -		 * vectors don't bother with assigning affinity.
> -		 */
> -		if (affd->pre_vectors + affd->post_vectors == min_vecs)
> -			affd = NULL;
>  	} else {
>  		if (WARN_ON(affd))
>  			affd = NULL;
> --
> 1.7.1
Christoph Hellwig March 1, 2017, 3:20 p.m. UTC | #2 
> @@ -1206,16 +1228,6 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
>  	if (flags & PCI_IRQ_AFFINITY) {
>  		if (!affd)
>  			affd = &msi_default_affd;
> -
> -		if (affd->pre_vectors + affd->post_vectors > min_vecs)
> -			return -EINVAL;

Actually I think we can leave this check here.

> -
> -		/*
> -		 * If there aren't any vectors left after applying the pre/post
> -		 * vectors don't bother with assigning affinity.
> -		 */
> -		if (affd->pre_vectors + affd->post_vectors == min_vecs)
> -			affd = NULL;

And only move this one down into the allocator helpers.
Madhani, Himanshu March 1, 2017, 11:27 p.m. UTC | #3 
> -----Original Message-----
> From: Christoph Hellwig [mailto:hch@lst.de]
> Sent: Wednesday, March 1, 2017 7:21 AM
> To: Madhani, Himanshu <Himanshu.Madhani@cavium.com>
> Cc: bhelgaas@google.com; linux-pci@vger.kernel.org; hch@lst.de
> Subject: Re: [PATCH] PCI/MSI: Only disable affinity settings if pre and post
> vector count is equal to max_vecs and not min_vecs
> 
> > @@ -1206,16 +1228,6 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev
> *dev, unsigned int min_vecs,
> >  	if (flags & PCI_IRQ_AFFINITY) {
> >  		if (!affd)
> >  			affd = &msi_default_affd;
> > -
> > -		if (affd->pre_vectors + affd->post_vectors > min_vecs)
> > -			return -EINVAL;
> 
> Actually I think we can leave this check here.
> 
> > -
> > -		/*
> > -		 * If there aren't any vectors left after applying the pre/post
> > -		 * vectors don't bother with assigning affinity.
> > -		 */
> > -		if (affd->pre_vectors + affd->post_vectors == min_vecs)
> > -			affd = NULL;
> 
> And only move this one down into the allocator helpers.

Will send out update soon. 

Thanks,
Himanshu
diff mbox

Patch

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 7f73bac..c61039b 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1091,6 +1091,17 @@  static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
 
 	for (;;) {
 		if (affd) {
+			if (affd->pre_vectors + affd->post_vectors > nvec)
+				return -EINVAL;
+			/*
+			 * If there aren't any vectors left after applying the
+			 * pre/post vectors don't bother with assigning
+			 * affinity.
+			 */
+			if (affd->pre_vectors + affd->post_vectors == nvec)
+				affd = NULL;
+		}
+		if (affd) {
 			nvec = irq_calc_affinity_vectors(nvec, affd);
 			if (nvec < minvec)
 				return -ENOSPC;
@@ -1138,6 +1149,17 @@  static int __pci_enable_msix_range(struct pci_dev *dev,
 
 	for (;;) {
 		if (affd) {
+			if (affd->pre_vectors + affd->post_vectors > nvec)
+				return -EINVAL;
+			/*
+			 * If there aren't any vectors left after applying the
+			 * pre/post vectors don't bother with assigning
+			 * affinity.
+			 */
+			if (affd->pre_vectors + affd->post_vectors == nvec)
+				affd = NULL;
+		}
+		if (affd) {
 			nvec = irq_calc_affinity_vectors(nvec, affd);
 			if (nvec < minvec)
 				return -ENOSPC;
@@ -1206,16 +1228,6 @@  int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
 	if (flags & PCI_IRQ_AFFINITY) {
 		if (!affd)
 			affd = &msi_default_affd;
-
-		if (affd->pre_vectors + affd->post_vectors > min_vecs)
-			return -EINVAL;
-
-		/*
-		 * If there aren't any vectors left after applying the pre/post
-		 * vectors don't bother with assigning affinity.
-		 */
-		if (affd->pre_vectors + affd->post_vectors == min_vecs)
-			affd = NULL;
 	} else {
 		if (WARN_ON(affd))
 			affd = NULL;