[S2IO]: Making MSIX as default intr_type

- Making MSIX as default intr_type
- Driver will test MSI-X by issuing test MSI-X vector and if fails it will
  fallback to INTA

Signed-off-by: Sivakumar Subramani <sivakumar.subramani@neterion.com>
Signed-off-by: Ramkrishna Vepa <ram.vepa@neterion.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 91 insertions, 2 deletions

diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index dd012322cdbe..588938204e20 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -37,7 +37,7 @@
  * tx_fifo_len: This too is an array of 8. Each element defines the number of
  * Tx descriptors that can be associated with each corresponding FIFO.
  * intr_type: This defines the type of interrupt. The values can be 0(INTA),
- *     2(MSI_X). Default value is '0(INTA)'
+ *     2(MSI_X). Default value is '2(MSI_X)'
  * lro: Specifies whether to enable Large Receive Offload (LRO) or not.
  *     Possible values '1' for enable '0' for disable. Default is '0'
  * lro_max_pkts: This parameter defines maximum number of packets can be
@@ -428,7 +428,7 @@ S2IO_PARM_INT(l3l4hdr_size, 128);
 /* Frequency of Rx desc syncs expressed as power of 2 */
 S2IO_PARM_INT(rxsync_frequency, 3);
 /* Interrupt type. Values can be 0(INTA), 2(MSI_X) */
-S2IO_PARM_INT(intr_type, 0);
+S2IO_PARM_INT(intr_type, 2);
 /* Large receive offload feature */
 S2IO_PARM_INT(lro, 0);
 /* Max pkts to be aggregated by LRO at one time. If not specified,
@@ -3773,6 +3773,59 @@ static int s2io_enable_msi_x(struct s2io_nic *nic)
         return 0;
 }
 
+/* Handle software interrupt used during MSI(X) test */
+static irqreturn_t __devinit s2io_test_intr(int irq, void *dev_id)
+{
+        struct s2io_nic *sp = dev_id;
+
+        sp->msi_detected = 1;
+        wake_up(&sp->msi_wait);
+
+        return IRQ_HANDLED;
+}
+
+/* Test interrupt path by forcing a a software IRQ */
+static int __devinit s2io_test_msi(struct s2io_nic *sp)
+{
+        struct pci_dev *pdev = sp->pdev;
+        struct XENA_dev_config __iomem *bar0 = sp->bar0;
+        int err;
+        u64 val64, saved64;
+
+        err = request_irq(sp->entries[1].vector, s2io_test_intr, 0,
+                        sp->name, sp);
+        if (err) {
+                DBG_PRINT(ERR_DBG, "%s: PCI %s: cannot assign irq %d\n",
+                       sp->dev->name, pci_name(pdev), pdev->irq);
+                return err;
+        }
+
+        init_waitqueue_head (&sp->msi_wait);
+        sp->msi_detected = 0;
+
+        saved64 = val64 = readq(&bar0->scheduled_int_ctrl);
+        val64 |= SCHED_INT_CTRL_ONE_SHOT;
+        val64 |= SCHED_INT_CTRL_TIMER_EN;
+        val64 |= SCHED_INT_CTRL_INT2MSI(1);
+        writeq(val64, &bar0->scheduled_int_ctrl);
+
+        wait_event_timeout(sp->msi_wait, sp->msi_detected, HZ/10);
+
+        if (!sp->msi_detected) {
+                /* MSI(X) test failed, go back to INTx mode */
+                DBG_PRINT(ERR_DBG, "%s: PCI %s: No interrupt was generated"
+                        "using MSI(X) during test\n", sp->dev->name,
+                        pci_name(pdev));
+
+                err = -EOPNOTSUPP;
+        }
+
+        free_irq(sp->entries[1].vector, sp);
+
+        writeq(saved64, &bar0->scheduled_int_ctrl);
+
+        return err;
+}
 /* ********************************************************* *
  * Functions defined below concern the OS part of the driver *
  * ********************************************************* */
@@ -3803,6 +3856,42 @@ static int s2io_open(struct net_device *dev)
 
         napi_enable(&sp->napi);
 
+        if (sp->intr_type == MSI_X) {
+                int ret = s2io_enable_msi_x(sp);
+
+                if (!ret) {
+                        u16 msi_control;
+
+                        ret = s2io_test_msi(sp);
+
+                        /* rollback MSI-X, will re-enable during add_isr() */
+                        kfree(sp->entries);
+                        sp->mac_control.stats_info->sw_stat.mem_freed +=
+                                (MAX_REQUESTED_MSI_X *
+                                sizeof(struct msix_entry));
+                        kfree(sp->s2io_entries);
+                        sp->mac_control.stats_info->sw_stat.mem_freed +=
+                                (MAX_REQUESTED_MSI_X *
+                                sizeof(struct s2io_msix_entry));
+                        sp->entries = NULL;
+                        sp->s2io_entries = NULL;
+
+                        pci_read_config_word(sp->pdev, 0x42, &msi_control);
+                        msi_control &= 0xFFFE; /* Disable MSI */
+                        pci_write_config_word(sp->pdev, 0x42, msi_control);
+
+                        pci_disable_msix(sp->pdev);
+
+                }
+                if (ret) {
+
+                        DBG_PRINT(ERR_DBG,
+                          "%s: MSI-X requested but failed to enable\n",
+                          dev->name);
+                        sp->intr_type = INTA;
+                }
+        }
+
         /* Initialize H/W and enable interrupts */
         err = s2io_card_up(sp);
         if (err) {