Staging: sxg: Make SXG driver use MSI-X interrupts if possible

Make Sahara SXG driver use MSI-X interrupts instead of line based interrupts
if possible. In case of problems in getting MSI-X vectors or MSI-X not being
supported, driver will fall back to use previous line based interrupts.

Signed-off-by: LinSysSoft Sahara Team <saharaproj@linsyssoft.com>
Signed-off-by: Mithlesh Thukral <mithlesh@linsyssoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/sxg/sxg.c b/drivers/staging/sxg/sxg.c
index 75c4982..287edb7 100644 (file)
--- a/drivers/staging/sxg/sxg.c
+++ b/drivers/staging/sxg/sxg.c
@@ -132,6 +132,9 @@ void sxg_free_sgl_buffers(struct adapter_t *adapter);
 void sxg_unmap_resources(struct adapter_t *adapter);
 void sxg_free_mcast_addrs(struct adapter_t *adapter);
 void sxg_collect_statistics(struct adapter_t *adapter);
+static int sxg_register_interrupt(struct adapter_t *adapter);
+static void sxg_remove_isr(struct adapter_t *adapter);
+static irqreturn_t sxg_isr(int irq, void *dev_id);
 
 #define XXXTODO 0
 
@@ -250,6 +253,131 @@ static struct sxg_trace_buffer LSxgTraceBuffer;
 #endif /* ATKDBG */
 static struct sxg_trace_buffer *SxgTraceBuffer = NULL;
 
+/*
+ * MSI Related API's
+ */
+int sxg_register_intr(struct adapter_t *adapter);
+int sxg_enable_msi_x(struct adapter_t *adapter);
+int sxg_add_msi_isr(struct adapter_t *adapter);
+void sxg_remove_msix_isr(struct adapter_t *adapter);
+int sxg_set_interrupt_capability(struct adapter_t *adapter);
+
+int sxg_set_interrupt_capability(struct adapter_t *adapter)
+{
+       int ret;
+
+       ret = sxg_enable_msi_x(adapter);
+       if (ret != STATUS_SUCCESS) {
+               adapter->msi_enabled = FALSE;
+               DBG_ERROR("sxg_set_interrupt_capability MSI-X Disable\n");
+       } else {
+               adapter->msi_enabled = TRUE;
+               DBG_ERROR("sxg_set_interrupt_capability MSI-X Enable\n");
+       }
+       return ret;
+}
+
+int sxg_register_intr(struct adapter_t *adapter)
+{
+       int ret = 0;
+
+       if (adapter->msi_enabled) {
+               ret = sxg_add_msi_isr(adapter);
+       }
+       else {
+               DBG_ERROR("MSI-X Enable Failed. Using Pin INT\n");
+               ret = sxg_register_interrupt(adapter);
+               if (ret != STATUS_SUCCESS) {
+                       DBG_ERROR("sxg_register_interrupt Failed\n");
+               }
+       }
+       return ret;
+}
+
+int sxg_enable_msi_x(struct adapter_t *adapter)
+{
+       int ret;
+
+       adapter->nr_msix_entries = 1;
+       adapter->msi_entries =  kmalloc(adapter->nr_msix_entries *
+                                       sizeof(struct msix_entry),GFP_KERNEL);
+       if (!adapter->msi_entries) {
+               DBG_ERROR("%s:MSI Entries memory allocation Failed\n",__func__);
+               return -ENOMEM;
+       }
+       memset(adapter->msi_entries, 0, adapter->nr_msix_entries *
+               sizeof(struct msix_entry));
+
+       ret = pci_enable_msix(adapter->pcidev, adapter->msi_entries,
+                               adapter->nr_msix_entries);
+       if (ret) {
+               DBG_ERROR("Enabling MSI-X with %d vectors failed\n",
+                               adapter->nr_msix_entries);
+               /*Should try with less vector returned.*/
+               kfree(adapter->msi_entries);
+               return STATUS_FAILURE; /*MSI-X Enable failed.*/
+       }
+       return (STATUS_SUCCESS);
+}
+
+int sxg_add_msi_isr(struct adapter_t *adapter)
+{
+       int ret,i;
+
+       if (!adapter->intrregistered) {
+               for (i=0; i<adapter->nr_msix_entries; i++) {
+                       ret = request_irq (adapter->msi_entries[i].vector,
+                                       sxg_isr,
+                                       IRQF_SHARED,
+                                       adapter->netdev->name,
+                                       adapter->netdev);
+                       if (ret) {
+                               DBG_ERROR("sxg: MSI-X request_irq (%s) "
+                                       "FAILED [%x]\n", adapter->netdev->name,
+                                        ret);
+                               return (ret);
+                       }
+               }
+       }
+       adapter->msi_enabled = TRUE;
+       adapter->intrregistered = 1;
+       adapter->IntRegistered = TRUE;
+       return (STATUS_SUCCESS);
+}
+
+void sxg_remove_msix_isr(struct adapter_t *adapter)
+{
+       int i,vector;
+       struct net_device *netdev = adapter->netdev;
+
+       for(i=0; i< adapter->nr_msix_entries;i++)
+       {
+               vector = adapter->msi_entries[i].vector;
+               DBG_ERROR("%s : Freeing IRQ vector#%d\n",__FUNCTION__,vector);
+               free_irq(vector,netdev);
+       }
+}
+
+
+static void sxg_remove_isr(struct adapter_t *adapter)
+{
+       struct net_device *netdev = adapter->netdev;
+       if (adapter->msi_enabled)
+               sxg_remove_msix_isr(adapter);
+       else
+               free_irq(adapter->netdev->irq, netdev);
+}
+
+void sxg_reset_interrupt_capability(struct adapter_t *adapter)
+{
+       if (adapter->msi_enabled) {
+               pci_disable_msix(adapter->pcidev);
+               kfree(adapter->msi_entries);
+               adapter->msi_entries = NULL;
+       }
+       return;
+}
+
 /*
  * sxg_download_microcode
  *
@@ -462,7 +590,7 @@ static int sxg_allocate_resources(struct adapter_t *adapter)
        /* Windows tells us how many CPUs it plans to use for */
        /* RSS */
        RssIds = SXG_RSS_CPU_COUNT(adapter);
-       IsrCount = adapter->MsiEnabled ? RssIds : 1;
+       IsrCount = adapter->msi_enabled ? RssIds : 1;
 
        DBG_ERROR("%s Setup the spinlocks\n", __func__);
 
@@ -950,6 +1078,9 @@ static int sxg_entry_probe(struct pci_dev *pcidev,
        netdev->get_stats = sxg_get_stats;
        netdev->set_multicast_list = sxg_mcast_set_list;
        SET_ETHTOOL_OPS(netdev, &sxg_nic_ethtool_ops);
+       err = sxg_set_interrupt_capability(adapter);
+       if (err != STATUS_SUCCESS)
+               DBG_ERROR("Cannot enable MSI-X capability\n");
 
        strcpy(netdev->name, "eth%d");
        /*  strcpy(netdev->name, pci_name(pcidev)); */
@@ -1025,7 +1156,6 @@ static void sxg_disable_interrupt(struct adapter_t *adapter)
                  adapter, adapter->InterruptsEnabled, 0, 0);
        /* For now, RSS is disabled with line based interrupts */
        ASSERT(adapter->RssEnabled == FALSE);
-       ASSERT(adapter->MsiEnabled == FALSE);
        /* Turn off interrupts by writing to the icr register. */
        WRITE_REG(adapter->UcodeRegs[0].Icr, SXG_ICR(0, SXG_ICR_DISABLE), TRUE);
 
@@ -1053,7 +1183,6 @@ static void sxg_enable_interrupt(struct adapter_t *adapter)
                  adapter, adapter->InterruptsEnabled, 0, 0);
        /* For now, RSS is disabled with line based interrupts */
        ASSERT(adapter->RssEnabled == FALSE);
-       ASSERT(adapter->MsiEnabled == FALSE);
        /* Turn on interrupts by writing to the icr register. */
        WRITE_REG(adapter->UcodeRegs[0].Icr, SXG_ICR(0, SXG_ICR_ENABLE), TRUE);
 
@@ -1154,7 +1283,6 @@ static void sxg_handle_interrupt(struct adapter_t *adapter, int *work_done,
                  adapter, adapter->IsrCopy[0], 0, 0);
        /* For now, RSS is disabled with line based interrupts */
        ASSERT(adapter->RssEnabled == FALSE);
-       ASSERT(adapter->MsiEnabled == FALSE);
 
        adapter->IsrCopy[0] = adapter->Isr[0];
        adapter->Isr[0] = 0;
@@ -1197,7 +1325,6 @@ static int sxg_poll(struct napi_struct *napi, int budget)
                netif_rx_complete(napi);
                WRITE_REG(adapter->UcodeRegs[0].Isr, 0, TRUE);
        }
-
        return work_done;
 }
 
@@ -1845,7 +1972,6 @@ static int sxg_register_interrupt(struct adapter_t *adapter)
                adapter->intrregistered = 1;
                adapter->IntRegistered = TRUE;
                /* Disable RSS with line-based interrupts */
-               adapter->MsiEnabled = FALSE;
                adapter->RssEnabled = FALSE;
                DBG_ERROR("sxg: %s AllocAdaptRsrcs adapter[%p] dev->irq[%x]\n",
                          __func__, adapter, adapter->netdev->irq);
@@ -1919,9 +2045,9 @@ static int sxg_if_init(struct adapter_t *adapter)
                }
                DBG_ERROR("\n");
        }
-       status = sxg_register_interrupt(adapter);
+       status = sxg_register_intr(adapter);
        if (status != STATUS_SUCCESS) {
-               DBG_ERROR("sxg_if_init: sxg_register_interrupt FAILED %x\n",
+               DBG_ERROR("sxg_if_init: sxg_register_intr FAILED %x\n",
                          status);
                sxg_deregister_interrupt(adapter);
                return (status);
@@ -2081,8 +2207,8 @@ int sxg_second_open(struct net_device * dev)
         SXG_ENABLE_ALL_INTERRUPTS(adapter);
 
        netif_carrier_on(dev);
-        spin_unlock_irqrestore(&sxg_global.driver_lock, sxg_global.flags);
         sxg_register_interrupt(adapter);
+       spin_unlock_irqrestore(&sxg_global.driver_lock, sxg_global.flags);
        return (STATUS_SUCCESS);
 
 }
@@ -2099,6 +2225,7 @@ static void __devexit sxg_entry_remove(struct pci_dev *pcidev)
 
        /* Deallocate Resources */
        unregister_netdev(dev);
+       sxg_reset_interrupt_capability(adapter);
        sxg_free_resources(adapter);
 
        ASSERT(adapter);
@@ -2133,7 +2260,7 @@ static int sxg_entry_halt(struct net_device *dev)
        unsigned long flags;
 
        RssIds = SXG_RSS_CPU_COUNT(adapter);
-       IsrCount = adapter->MsiEnabled ? RssIds : 1;
+       IsrCount = adapter->msi_enabled ? RssIds : 1;
 
        napi_disable(&adapter->napi);
        spin_lock_irqsave(&sxg_global.driver_lock, sxg_global.flags);
@@ -2147,9 +2274,6 @@ static int sxg_entry_halt(struct net_device *dev)
        DBG_ERROR("sxg: %s (%s) set adapter[%p] state to ADAPT_DOWN(%d)\n",
                  __func__, dev->name, adapter, adapter->state);
 
-       DBG_ERROR("sxg: %s (%s) EXIT\n", __func__, dev->name);
-       DBG_ERROR("sxg: %s EXIT\n", __func__);
-
        /* Disable interrupts */
        SXG_DISABLE_ALL_INTERRUPTS(adapter);
 
@@ -2196,11 +2320,13 @@ static int sxg_entry_halt(struct net_device *dev)
        memset(adapter->XmtRingZeroIndex, 0, sizeof(u32));
        spin_unlock_irqrestore(&adapter->XmtZeroLock, flags);
 
-
        for (i = 0; i < SXG_MAX_RSS; i++) {
                adapter->NextEvent[i] = 0;
        }
        atomic_set(&adapter->pending_allocations, 0);
+       adapter->intrregistered = 0;
+       sxg_remove_isr(adapter);
+       DBG_ERROR("sxg: %s (%s) EXIT\n", __FUNCTION__, dev->name);
        return (STATUS_SUCCESS);
 }
 
@@ -3451,9 +3577,8 @@ void sxg_unmap_resources(struct adapter_t *adapter)
 void sxg_free_resources(struct adapter_t *adapter)
 {
        u32 RssIds, IsrCount;
-       struct net_device *netdev = adapter->netdev;
        RssIds = SXG_RSS_CPU_COUNT(adapter);
-       IsrCount = adapter->MsiEnabled ? RssIds : 1;
+       IsrCount = adapter->msi_enabled ? RssIds : 1;
 
        if (adapter->BasicAllocations == FALSE) {
                /*
@@ -3463,9 +3588,6 @@ void sxg_free_resources(struct adapter_t *adapter)
                return;
        }
 
-       /* Free Irq */
-       free_irq(adapter->netdev->irq, netdev);
-
        if (!(IsListEmpty(&adapter->AllRcvBlocks))) {
                sxg_free_rcvblocks(adapter);
        }
@@ -3877,7 +3999,7 @@ static int sxg_initialize_adapter(struct adapter_t *adapter)
                  adapter, 0, 0, 0);
 
        RssIds = 1;             /*  XXXTODO  SXG_RSS_CPU_COUNT(adapter); */
-       IsrCount = adapter->MsiEnabled ? RssIds : 1;
+       IsrCount = adapter->msi_enabled ? RssIds : 1;
 
        /*
         * Sanity check SXG_UCODE_REGS structure definition to

diff --git a/drivers/staging/sxg/sxg.h b/drivers/staging/sxg/sxg.h
index e937d4b..7bf0a43 100644 (file)
--- a/drivers/staging/sxg/sxg.h
+++ b/drivers/staging/sxg/sxg.h
@@ -676,7 +676,7 @@ struct adapter_t {
        u32             DumpCmdRunning:1;       /* Dump command in progress */
        u32             DebugRunning:1;         /* AGDB debug in progress */
        u32             JumboEnabled:1;         /* Jumbo frames enabled */
-       u32             MsiEnabled:1;           /* MSI interrupt enabled */
+       u32             msi_enabled:1;          /* MSI interrupt enabled */
        u32             RssEnabled:1;           /* RSS Enabled */
        u32             FailOnBadEeprom:1;      /* Fail on Bad Eeprom */
        u32             DiagStart:1;            /* Init adapter for diagnostic start */
@@ -709,6 +709,9 @@ struct adapter_t {
        /*      PSXG_DUMP_CMD   DumpBuffer; */                  /* 68k - Cmd and Buffer */
        /*      dma_addr_t      PDumpBuffer; */         /* Physical address */
        /*#endif */ /* SXG_FAILURE_DUMP */
+       /*MSI-X related data elements*/
+       u32 nr_msix_entries;
+       struct msix_entry *msi_entries;
 };
 
 #if SLIC_DUMP_ENABLED