tg3: Add MSI-X support

This patch adds MSI-X support.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 81 insertions, 27 deletions

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 7717eae1221d..12ead83bd06f 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -160,6 +160,7 @@ MODULE_FIRMWARE(FIRMWARE_TG3);
 MODULE_FIRMWARE(FIRMWARE_TG3TSO);
 MODULE_FIRMWARE(FIRMWARE_TG3TSO5);
 
+#define TG3_RSS_MIN_NUM_MSIX_VECS       2
 
 static int tg3_debug = -1;      /* -1 == use TG3_DEF_MSG_ENABLE as value */
 module_param(tg3_debug, int, 0);
@@ -7767,7 +7768,7 @@ static int tg3_request_irq(struct tg3 *tp, int irq_num)
                 name[IFNAMSIZ-1] = 0;
         }
 
-        if (tp->tg3_flags2 & TG3_FLG2_USING_MSI) {
+        if (tp->tg3_flags2 & TG3_FLG2_USING_MSI_OR_MSIX) {
                 fn = tg3_msi;
                 if (tp->tg3_flags2 & TG3_FLG2_1SHOT_MSI)
                         fn = tg3_msi_1shot;
@@ -7928,34 +7929,81 @@ static int tg3_request_firmware(struct tg3 *tp)
         return 0;
 }
 
+static bool tg3_enable_msix(struct tg3 *tp)
+{
+        int i, rc, cpus = num_online_cpus();
+        struct msix_entry msix_ent[tp->irq_max];
+
+        if (cpus == 1)
+                /* Just fallback to the simpler MSI mode. */
+                return false;
+
+        /*
+         * We want as many rx rings enabled as there are cpus.
+         * The first MSIX vector only deals with link interrupts, etc,
+         * so we add one to the number of vectors we are requesting.
+         */
+        tp->irq_cnt = min_t(unsigned, cpus + 1, tp->irq_max);
+
+        for (i = 0; i < tp->irq_max; i++) {
+                msix_ent[i].entry  = i;
+                msix_ent[i].vector = 0;
+        }
+
+        rc = pci_enable_msix(tp->pdev, msix_ent, tp->irq_cnt);
+        if (rc != 0) {
+                if (rc < TG3_RSS_MIN_NUM_MSIX_VECS)
+                        return false;
+                if (pci_enable_msix(tp->pdev, msix_ent, rc))
+                        return false;
+                printk(KERN_NOTICE
+                       "%s: Requested %d MSI-X vectors, received %d\n",
+                       tp->dev->name, tp->irq_cnt, rc);
+                tp->irq_cnt = rc;
+        }
+
+        for (i = 0; i < tp->irq_max; i++)
+                tp->napi[i].irq_vec = msix_ent[i].vector;
+
+        return true;
+}
+
 static void tg3_ints_init(struct tg3 *tp)
 {
-        if (tp->tg3_flags & TG3_FLAG_SUPPORT_MSI) {
+        if ((tp->tg3_flags & TG3_FLAG_SUPPORT_MSI_OR_MSIX) &&
+            !(tp->tg3_flags & TG3_FLAG_TAGGED_STATUS)) {
                 /* All MSI supporting chips should support tagged
                  * status.  Assert that this is the case.
                  */
-                if (!(tp->tg3_flags & TG3_FLAG_TAGGED_STATUS)) {
-                        printk(KERN_WARNING PFX "%s: MSI without TAGGED? "
-                               "Not using MSI.\n", tp->dev->name);
-                } else if (pci_enable_msi(tp->pdev) == 0) {
-                        u32 msi_mode;
-
-                        msi_mode = tr32(MSGINT_MODE);
-                        tw32(MSGINT_MODE, msi_mode | MSGINT_MODE_ENABLE);
-                        tp->tg3_flags2 |= TG3_FLG2_USING_MSI;
-                }
+                printk(KERN_WARNING PFX "%s: MSI without TAGGED? "
+                       "Not using MSI.\n", tp->dev->name);
+                goto defcfg;
         }
 
-        tp->irq_cnt = 1;
-        tp->napi[0].irq_vec = tp->pdev->irq;
+        if ((tp->tg3_flags & TG3_FLAG_SUPPORT_MSIX) && tg3_enable_msix(tp))
+                tp->tg3_flags2 |= TG3_FLG2_USING_MSIX;
+        else if ((tp->tg3_flags & TG3_FLAG_SUPPORT_MSI) &&
+                 pci_enable_msi(tp->pdev) == 0)
+                tp->tg3_flags2 |= TG3_FLG2_USING_MSI;
+
+        if (tp->tg3_flags2 & TG3_FLG2_USING_MSI_OR_MSIX) {
+                u32 msi_mode = tr32(MSGINT_MODE);
+                tw32(MSGINT_MODE, msi_mode | MSGINT_MODE_ENABLE);
+        }
+defcfg:
+        if (!(tp->tg3_flags2 & TG3_FLG2_USING_MSIX)) {
+                tp->irq_cnt = 1;
+                tp->napi[0].irq_vec = tp->pdev->irq;
+        }
 }
 
 static void tg3_ints_fini(struct tg3 *tp)
 {
-                if (tp->tg3_flags2 & TG3_FLG2_USING_MSI) {
-                        pci_disable_msi(tp->pdev);
-                        tp->tg3_flags2 &= ~TG3_FLG2_USING_MSI;
-                }
+        if (tp->tg3_flags2 & TG3_FLG2_USING_MSIX)
+                pci_disable_msix(tp->pdev);
+        else if (tp->tg3_flags2 & TG3_FLG2_USING_MSI)
+                pci_disable_msi(tp->pdev);
+        tp->tg3_flags2 &= ~TG3_FLG2_USING_MSI_OR_MSIX;
 }
 
 static int tg3_open(struct net_device *dev)
@@ -7992,14 +8040,18 @@ static int tg3_open(struct net_device *dev)
 
         tg3_full_unlock(tp);
 
+        /*
+         * Setup interrupts first so we know how
+         * many NAPI resources to allocate
+         */
+        tg3_ints_init(tp);
+
         /* The placement of this call is tied
          * to the setup and use of Host TX descriptors.
          */
         err = tg3_alloc_consistent(tp);
         if (err)
-                return err;
-
-        tg3_ints_init(tp);
+                goto err_out1;
 
         napi_enable(&tp->napi[0].napi);
 
@@ -8014,7 +8066,7 @@ static int tg3_open(struct net_device *dev)
         }
 
         if (err)
-                goto err_out1;
+                goto err_out2;
 
         tg3_full_lock(tp, 0);
 
@@ -8043,7 +8095,7 @@ static int tg3_open(struct net_device *dev)
         tg3_full_unlock(tp);
 
         if (err)
-                goto err_out2;
+                goto err_out3;
 
         if (tp->tg3_flags2 & TG3_FLG2_USING_MSI) {
                 err = tg3_test_msi(tp);
@@ -8054,7 +8106,7 @@ static int tg3_open(struct net_device *dev)
                         tg3_free_rings(tp);
                         tg3_full_unlock(tp);
 
-                        goto err_out1;
+                        goto err_out2;
                 }
 
                 if (tp->tg3_flags2 & TG3_FLG2_USING_MSI) {
@@ -8081,16 +8133,18 @@ static int tg3_open(struct net_device *dev)
 
         return 0;
 
-err_out2:
+err_out3:
         for (i = tp->irq_cnt - 1; i >= 0; i--) {
                 struct tg3_napi *tnapi = &tp->napi[i];
                 free_irq(tnapi->irq_vec, tnapi);
         }
 
-err_out1:
+err_out2:
         napi_disable(&tp->napi[0].napi);
-        tg3_ints_fini(tp);
         tg3_free_consistent(tp);
+
+err_out1:
+        tg3_ints_fini(tp);
         return err;
 }