Patchwork [RFC,55/77] ntb: Update MSI/MSI-X interrupts enablement code

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Submitter Alexander Gordeev
Date Oct. 2, 2013, 10:49 a.m.
Message ID <49eb592e15aaec804f9c11ca132d2b85c516aefa.1380703263.git.agordeev@redhat.com>
Download mbox | patch
Permalink /patch/279948/
State RFC
Headers show

Comments

Alexander Gordeev - Oct. 2, 2013, 10:49 a.m.
As result of recent re-design of the MSI/MSI-X interrupts enabling
pattern this driver has to be updated to use the new technique to
obtain a optimal number of MSI/MSI-X interrupts required.

Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
---
 drivers/ntb/ntb_hw.c |   41 +++++++++++++----------------------------
 drivers/ntb/ntb_hw.h |    2 --
 2 files changed, 13 insertions(+), 30 deletions(-)
Jon Mason - Oct. 3, 2013, 1:02 a.m.
On Wed, Oct 02, 2013 at 12:49:11PM +0200, Alexander Gordeev wrote:
> As result of recent re-design of the MSI/MSI-X interrupts enabling
> pattern this driver has to be updated to use the new technique to
> obtain a optimal number of MSI/MSI-X interrupts required.
> 
> Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
> ---
>  drivers/ntb/ntb_hw.c |   41 +++++++++++++----------------------------
>  drivers/ntb/ntb_hw.h |    2 --
>  2 files changed, 13 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/ntb/ntb_hw.c b/drivers/ntb/ntb_hw.c
> index eccd5e5..7776429 100644
> --- a/drivers/ntb/ntb_hw.c
> +++ b/drivers/ntb/ntb_hw.c
> @@ -1032,23 +1032,26 @@ static int ntb_setup_msix(struct ntb_device *ndev)
>  	struct msix_entry *msix;
>  	int msix_entries;
>  	int rc, i;
> -	u16 val;
>  
> -	if (!pdev->msix_cap) {
> -		rc = -EIO;
> +	rc = pci_msix_table_size(pdev);
> +	if (rc < 0)
>  		goto err;
> -	}
>  
> -	rc = pci_read_config_word(pdev, pdev->msix_cap + PCI_MSIX_FLAGS, &val);
> -	if (rc)
> +	/*
> +	 * On SNB, the link interrupt is always tied to 4th vector.  If
> +	 * we can't get all 4, then we can't use MSI-X.
> +	 */
> +	if ((rc < SNB_MSIX_CNT) && (ndev->hw_type != BWD_HW)) {

Please check for the HW type first, and then compare to
ndev->limits.msix_cnt (which will be SNB_MSIX_CNT on SNB HW).  Also,
put the comment inside the if statement and remove the unecessary "()"
around the comparisons.  OCD on my part, but I like it that way.  

> +		rc = -ENOSPC;
>  		goto err;
> -
> -	msix_entries = msix_table_size(val);
> -	if (msix_entries > ndev->limits.msix_cnt) {
> +	}

else if...

> +	if (rc > ndev->limits.msix_cnt) {
>  		rc = -EINVAL;
>  		goto err;
>  	}
>  
> +	msix_entries = rc;
> +
>  	ndev->msix_entries = kmalloc(sizeof(struct msix_entry) * msix_entries,
>  				     GFP_KERNEL);
>  	if (!ndev->msix_entries) {
> @@ -1060,26 +1063,8 @@ static int ntb_setup_msix(struct ntb_device *ndev)
>  		ndev->msix_entries[i].entry = i;
>  
>  	rc = pci_enable_msix(pdev, ndev->msix_entries, msix_entries);
> -	if (rc < 0)
> +	if (rc)
>  		goto err1;
> -	if (rc > 0) {
> -		/* On SNB, the link interrupt is always tied to 4th vector.  If
> -		 * we can't get all 4, then we can't use MSI-X.
> -		 */
> -		if ((rc < SNB_MSIX_CNT) && (ndev->hw_type != BWD_HW)) {
> -			rc = -EIO;
> -			goto err1;
> -		}
> -
> -		dev_warn(&pdev->dev,
> -			 "Only %d MSI-X vectors.  Limiting the number of queues to that number.\n",
> -			 rc);
> -		msix_entries = rc;
> -
> -		rc = pci_enable_msix(pdev, ndev->msix_entries, msix_entries);
> -		if (rc)
> -			goto err1;
> -	}
>  
>  	for (i = 0; i < msix_entries; i++) {
>  		msix = &ndev->msix_entries[i];
> diff --git a/drivers/ntb/ntb_hw.h b/drivers/ntb/ntb_hw.h
> index 0a31ced..50bd760 100644
> --- a/drivers/ntb/ntb_hw.h
> +++ b/drivers/ntb/ntb_hw.h
> @@ -60,8 +60,6 @@
>  #define PCI_DEVICE_ID_INTEL_NTB_SS_HSX		0x2F0F
>  #define PCI_DEVICE_ID_INTEL_NTB_B2B_BWD		0x0C4E
>  
> -#define msix_table_size(control)	((control & PCI_MSIX_FLAGS_QSIZE)+1)

Good riddance!  :-)

> -
>  #ifndef readq
>  static inline u64 readq(void __iomem *addr)
>  {
> -- 
> 1.7.7.6
> 
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Patch

diff --git a/drivers/ntb/ntb_hw.c b/drivers/ntb/ntb_hw.c
index eccd5e5..7776429 100644
--- a/drivers/ntb/ntb_hw.c
+++ b/drivers/ntb/ntb_hw.c
@@ -1032,23 +1032,26 @@  static int ntb_setup_msix(struct ntb_device *ndev)
 	struct msix_entry *msix;
 	int msix_entries;
 	int rc, i;
-	u16 val;
 
-	if (!pdev->msix_cap) {
-		rc = -EIO;
+	rc = pci_msix_table_size(pdev);
+	if (rc < 0)
 		goto err;
-	}
 
-	rc = pci_read_config_word(pdev, pdev->msix_cap + PCI_MSIX_FLAGS, &val);
-	if (rc)
+	/*
+	 * On SNB, the link interrupt is always tied to 4th vector.  If
+	 * we can't get all 4, then we can't use MSI-X.
+	 */
+	if ((rc < SNB_MSIX_CNT) && (ndev->hw_type != BWD_HW)) {
+		rc = -ENOSPC;
 		goto err;
-
-	msix_entries = msix_table_size(val);
-	if (msix_entries > ndev->limits.msix_cnt) {
+	}
+	if (rc > ndev->limits.msix_cnt) {
 		rc = -EINVAL;
 		goto err;
 	}
 
+	msix_entries = rc;
+
 	ndev->msix_entries = kmalloc(sizeof(struct msix_entry) * msix_entries,
 				     GFP_KERNEL);
 	if (!ndev->msix_entries) {
@@ -1060,26 +1063,8 @@  static int ntb_setup_msix(struct ntb_device *ndev)
 		ndev->msix_entries[i].entry = i;
 
 	rc = pci_enable_msix(pdev, ndev->msix_entries, msix_entries);
-	if (rc < 0)
+	if (rc)
 		goto err1;
-	if (rc > 0) {
-		/* On SNB, the link interrupt is always tied to 4th vector.  If
-		 * we can't get all 4, then we can't use MSI-X.
-		 */
-		if ((rc < SNB_MSIX_CNT) && (ndev->hw_type != BWD_HW)) {
-			rc = -EIO;
-			goto err1;
-		}
-
-		dev_warn(&pdev->dev,
-			 "Only %d MSI-X vectors.  Limiting the number of queues to that number.\n",
-			 rc);
-		msix_entries = rc;
-
-		rc = pci_enable_msix(pdev, ndev->msix_entries, msix_entries);
-		if (rc)
-			goto err1;
-	}
 
 	for (i = 0; i < msix_entries; i++) {
 		msix = &ndev->msix_entries[i];
diff --git a/drivers/ntb/ntb_hw.h b/drivers/ntb/ntb_hw.h
index 0a31ced..50bd760 100644
--- a/drivers/ntb/ntb_hw.h
+++ b/drivers/ntb/ntb_hw.h
@@ -60,8 +60,6 @@ 
 #define PCI_DEVICE_ID_INTEL_NTB_SS_HSX		0x2F0F
 #define PCI_DEVICE_ID_INTEL_NTB_B2B_BWD		0x0C4E
 
-#define msix_table_size(control)	((control & PCI_MSIX_FLAGS_QSIZE)+1)
-
 #ifndef readq
 static inline u64 readq(void __iomem *addr)
 {