[PATCH v2 3/4] ntb: Split ntb_setup_msix() into separate BWD/SNB routines

From: Alexander Gordeev
Date: Fri Feb 21 2014 - 10:48:14 EST


This is an cleanup effort to make ntb_setup_msix() more
readable - use ntb_setup_bwd_msix() to init MSI-Xs on
BWD hardware and ntb_setup_snb_msix() - on SNB hardware.

Function ntb_setup_snb_msix() also initializes MSI-Xs the
way it should has been done - looping pci_enable_msix()
until success or failure.

Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxx>
Cc: Jon Mason <jon.mason@xxxxxxxxx>
Cc: linux-pci@xxxxxxxxxxxxxxx
---
drivers/ntb/ntb_hw.c | 170 +++++++++++++++++++++++++++++++-------------------
1 files changed, 106 insertions(+), 64 deletions(-)

diff --git a/drivers/ntb/ntb_hw.c b/drivers/ntb/ntb_hw.c
index 53468f4..0472045 100644
--- a/drivers/ntb/ntb_hw.c
+++ b/drivers/ntb/ntb_hw.c
@@ -1079,6 +1079,107 @@ static irqreturn_t ntb_interrupt(int irq, void *dev)
return IRQ_HANDLED;
}

+static int ntb_setup_snb_msix(struct ntb_device *ndev, int msix_entries)
+{
+ struct pci_dev *pdev = ndev->pdev;
+ struct msix_entry *msix;
+ int rc, i;
+
+ if (msix_entries < SNB_MSIX_CNT)
+ return -ENOSPC;
+
+ rc = pci_enable_msix(pdev, ndev->msix_entries, msix_entries);
+ if (rc < 0)
+ return rc;
+ else if (rc > 0)
+ return -ENOSPC;
+
+ for (i = 0; i < msix_entries; i++) {
+ msix = &ndev->msix_entries[i];
+ WARN_ON(!msix->vector);
+
+ if (i == msix_entries - 1) {
+ rc = request_irq(msix->vector,
+ xeon_event_msix_irq, 0,
+ "ntb-event-msix", ndev);
+ if (rc)
+ goto err;
+ } else {
+ rc = request_irq(msix->vector,
+ xeon_callback_msix_irq, 0,
+ "ntb-callback-msix",
+ &ndev->db_cb[i]);
+ if (rc)
+ goto err;
+ }
+ }
+
+ ndev->num_msix = msix_entries;
+ ndev->max_cbs = msix_entries - 1;
+
+ return 0;
+
+err:
+ while (--i >= 0) {
+ msix = &ndev->msix_entries[i];
+ WARN_ON(i == ndev->num_msix - 1);
+
+ if (i == ndev->num_msix - 1)
+ free_irq(msix->vector, ndev);
+ else
+ free_irq(msix->vector, &ndev->db_cb[i]);
+ }
+
+ pci_disable_msix(pdev);
+ ndev->num_msix = 0;
+
+ return rc;
+}
+
+static int ntb_setup_bwd_msix(struct ntb_device *ndev, int msix_entries)
+{
+ struct pci_dev *pdev = ndev->pdev;
+ struct msix_entry *msix;
+ int rc, i;
+
+retry:
+ rc = pci_enable_msix(pdev, ndev->msix_entries, msix_entries);
+ if (rc < 0)
+ return rc;
+ else if (rc > 0) {
+ dev_warn(&pdev->dev,
+ "Only %d MSI-X vectors. "
+ "Limiting the number of queues to that number.\n",
+ rc);
+ msix_entries = rc;
+ goto retry;
+ }
+
+ for (i = 0; i < msix_entries; i++) {
+ msix = &ndev->msix_entries[i];
+ WARN_ON(!msix->vector);
+
+ rc = request_irq(msix->vector, bwd_callback_msix_irq, 0,
+ "ntb-callback-msix", &ndev->db_cb[i]);
+ if (rc)
+ goto err;
+ }
+
+ ndev->num_msix = msix_entries;
+ ndev->max_cbs = msix_entries;
+
+ return 0;
+
+err:
+ while (--i >= 0)
+ free_irq(msix->vector, &ndev->db_cb[i]);
+
+ pci_disable_msix(pdev);
+ ndev->num_msix = 0;
+
+ return rc;
+}
+
static int ntb_setup_msix(struct ntb_device *ndev)
{
struct pci_dev *pdev = ndev->pdev;
@@ -1105,78 +1206,19 @@ static int ntb_setup_msix(struct ntb_device *ndev)
for (i = 0; i < msix_entries; i++)
ndev->msix_entries[i].entry = i;

- rc = pci_enable_msix(pdev, ndev->msix_entries, msix_entries);
- if (rc < 0)
- 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 (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];
- WARN_ON(!msix->vector);
-
- /* Use the last MSI-X vector for Link status */
- if (ndev->hw_type == BWD_HW) {
- rc = request_irq(msix->vector, bwd_callback_msix_irq, 0,
- "ntb-callback-msix", &ndev->db_cb[i]);
- if (rc)
- goto err2;
- } else {
- if (i == msix_entries - 1) {
- rc = request_irq(msix->vector,
- xeon_event_msix_irq, 0,
- "ntb-event-msix", ndev);
- if (rc)
- goto err2;
- } else {
- rc = request_irq(msix->vector,
- xeon_callback_msix_irq, 0,
- "ntb-callback-msix",
- &ndev->db_cb[i]);
- if (rc)
- goto err2;
- }
- }
- }
-
- ndev->num_msix = msix_entries;
if (ndev->hw_type == BWD_HW)
- ndev->max_cbs = msix_entries;
+ rc = ntb_setup_bwd_msix(ndev, msix_entries);
else
- ndev->max_cbs = msix_entries - 1;
+ rc = ntb_setup_snb_msix(ndev, msix_entries);
+ if (rc)
+ goto err1;

return 0;

-err2:
- while (--i >= 0) {
- msix = &ndev->msix_entries[i];
- if (ndev->hw_type != BWD_HW && i == ndev->num_msix - 1)
- free_irq(msix->vector, ndev);
- else
- free_irq(msix->vector, &ndev->db_cb[i]);
- }
- pci_disable_msix(pdev);
err1:
kfree(ndev->msix_entries);
- dev_err(&pdev->dev, "Error allocating MSI-X interrupt\n");
err:
- ndev->num_msix = 0;
+ dev_err(&pdev->dev, "Error allocating MSI-X interrupt\n");
return rc;
}

--
1.7.7.6

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