Make the various driver MSIX setup routines fallback to MSI more

gracefully. This change was suggested by Marius Strobl, thank you.

PR: kern/181016
MFC after: ASAP

4 files changed, 50 insertions, 50 deletions

diff --git a/sys/dev/e1000/if_em.c b/sys/dev/e1000/if_em.c
index 140fc77..9499953 100644
--- a/sys/dev/e1000/if_em.c
+++ b/sys/dev/e1000/if_em.c
@@ -2750,7 +2750,7 @@ static int
 em_setup_msix(struct adapter *adapter)
 {
 	device_t dev = adapter->dev;
-	int val = 0;
+	int val;
 
 	/*
 	** Setup MSI/X for Hartwell: tests have shown
@@ -2764,17 +2764,17 @@ em_setup_msix(struct adapter *adapter)
 		int rid = PCIR_BAR(EM_MSIX_BAR);
 		adapter->msix_mem = bus_alloc_resource_any(dev,
 		    SYS_RES_MEMORY, &rid, RF_ACTIVE);
-       		if (!adapter->msix_mem) {
+       		if (adapter->msix_mem == NULL) {
 			/* May not be enabled */
                		device_printf(adapter->dev,
 			    "Unable to map MSIX table \n");
 			goto msi;
        		}
 		val = pci_msix_count(dev); 
-		/* We only need 3 vectors */
-		if (val > 3)
+		/* We only need/want 3 vectors */
+		if (val >= 3)
 			val = 3;
-		if ((val != 3) && (val != 5)) {
+		else {
 			bus_release_resource(dev, SYS_RES_MEMORY,
 			    PCIR_BAR(EM_MSIX_BAR), adapter->msix_mem);
 			adapter->msix_mem = NULL;
@@ -2787,14 +2787,13 @@ em_setup_msix(struct adapter *adapter)
 			device_printf(adapter->dev,
 			    "Using MSIX interrupts "
 			    "with %d vectors\n", val);
+			return (val);
 		}
-
-		return (val);
+		/* Fall through to MSI */
 	}
 msi:
-       	val = pci_msi_count(dev);
-       	if (val == 1 && pci_alloc_msi(dev, &val) == 0) {
-               	adapter->msix = 1;
+       	val = 1;
+       	if (pci_alloc_msi(dev, &val) == 0) {
                	device_printf(adapter->dev,"Using an MSI interrupt\n");
 		return (val);
 	} 
diff --git a/sys/dev/e1000/if_igb.c b/sys/dev/e1000/if_igb.c
index 4e8bd0f..d524832 100644
--- a/sys/dev/e1000/if_igb.c
+++ b/sys/dev/e1000/if_igb.c
@@ -2842,24 +2842,19 @@ igb_setup_msix(struct adapter *adapter)
 		goto msi;
 
 	/* First try MSI/X */
+	msgs = pci_msix_count(dev); 
+	if (msgs == 0)
+		goto msi;
 	rid = PCIR_BAR(IGB_MSIX_BAR);
 	adapter->msix_mem = bus_alloc_resource_any(dev,
 	    SYS_RES_MEMORY, &rid, RF_ACTIVE);
-       	if (!adapter->msix_mem) {
+       	if (adapter->msix_mem == NULL) {
 		/* May not be enabled */
 		device_printf(adapter->dev,
 		    "Unable to map MSIX table \n");
 		goto msi;
 	}
 
-	msgs = pci_msix_count(dev); 
-	if (msgs == 0) { /* system has msix disabled */
-		bus_release_resource(dev, SYS_RES_MEMORY,
-		    PCIR_BAR(IGB_MSIX_BAR), adapter->msix_mem);
-		adapter->msix_mem = NULL;
-		goto msi;
-	}
-
 	/* Figure out a reasonable auto config value */
 	queues = (mp_ncpus > (msgs-1)) ? (msgs-1) : mp_ncpus;
 
@@ -2902,20 +2897,27 @@ igb_setup_msix(struct adapter *adapter)
 		    "MSIX Configuration Problem, "
 		    "%d vectors configured, but %d queues wanted!\n",
 		    msgs, want);
-		return (0);
+		goto msi;
 	}
-	if ((msgs) && pci_alloc_msix(dev, &msgs) == 0) {
+	if (pci_alloc_msix(dev, &msgs) == 0) {
                	device_printf(adapter->dev,
 		    "Using MSIX interrupts with %d vectors\n", msgs);
 		adapter->num_queues = queues;
 		return (msgs);
 	}
+	/* Fallback to MSI configuration */
 msi:
-       	msgs = pci_msi_count(dev);
-	if (msgs == 1 && pci_alloc_msi(dev, &msgs) == 0) {
+       	if (adapter->msix_mem != NULL) {
+		bus_release_resource(dev, SYS_RES_MEMORY,
+		    PCIR_BAR(IGB_MSIX_BAR), adapter->msix_mem);
+		adapter->msix_mem = NULL;
+	}
+       	msgs = 1;
+	if (pci_alloc_msi(dev, &msgs) == 0) {
 		device_printf(adapter->dev," Using MSI interrupt\n");
 		return (msgs);
 	}
+	/* Default to a legacy interrupt */
 	return (0);
 }
 
diff --git a/sys/dev/ixgbe/ixgbe.c b/sys/dev/ixgbe/ixgbe.c
index 9ac585a..ca4aa66 100644
--- a/sys/dev/ixgbe/ixgbe.c
+++ b/sys/dev/ixgbe/ixgbe.c
@@ -2415,29 +2415,24 @@ ixgbe_setup_msix(struct adapter *adapter)
 		goto msi;
 
 	/* First try MSI/X */
+	msgs = pci_msix_count(dev); 
+	if (msgs == 0)
+		goto msi;
 	rid = PCIR_BAR(MSIX_82598_BAR);
 	adapter->msix_mem = bus_alloc_resource_any(dev,
 	    SYS_RES_MEMORY, &rid, RF_ACTIVE);
-       	if (!adapter->msix_mem) {
+       	if (adapter->msix_mem == NULL) {
 		rid += 4;	/* 82599 maps in higher BAR */
 		adapter->msix_mem = bus_alloc_resource_any(dev,
 		    SYS_RES_MEMORY, &rid, RF_ACTIVE);
 	}
-       	if (!adapter->msix_mem) {
+       	if (adapter->msix_mem == NULL) {
 		/* May not be enabled */
 		device_printf(adapter->dev,
 		    "Unable to map MSIX table \n");
 		goto msi;
 	}
 
-	msgs = pci_msix_count(dev); 
-	if (msgs == 0) { /* system has msix disabled */
-		bus_release_resource(dev, SYS_RES_MEMORY,
-		    rid, adapter->msix_mem);
-		adapter->msix_mem = NULL;
-		goto msi;
-	}
-
 	/* Figure out a reasonable auto config value */
 	queues = (mp_ncpus > (msgs-1)) ? (msgs-1) : mp_ncpus;
 
@@ -2459,21 +2454,27 @@ ixgbe_setup_msix(struct adapter *adapter)
 		    "MSIX Configuration Problem, "
 		    "%d vectors but %d queues wanted!\n",
 		    msgs, want);
-		return (0); /* Will go to Legacy setup */
+		goto msi;
 	}
-	if ((msgs) && pci_alloc_msix(dev, &msgs) == 0) {
+	if (pci_alloc_msix(dev, &msgs) == 0) {
                	device_printf(adapter->dev,
 		    "Using MSIX interrupts with %d vectors\n", msgs);
 		adapter->num_queues = queues;
 		return (msgs);
 	}
 msi:
-       	msgs = pci_msi_count(dev);
-       	if (msgs == 1 && pci_alloc_msi(dev, &msgs) == 0)
+       	if (adapter->msix_mem != NULL) {
+		bus_release_resource(dev, SYS_RES_MEMORY,
+		    rid, adapter->msix_mem);
+		adapter->msix_mem = NULL;
+	}
+       	msgs = 1;
+       	if (pci_alloc_msi(dev, &msgs) == 0) {
                	device_printf(adapter->dev,"Using an MSI interrupt\n");
-	else
-               	device_printf(adapter->dev,"Using a Legacy interrupt\n");
-	return (msgs);
+		return (msgs);
+	}
+	device_printf(adapter->dev,"Using a Legacy interrupt\n");
+	return (0);
 }
 
 
diff --git a/sys/dev/ixgbe/ixv.c b/sys/dev/ixgbe/ixv.c
index e51cdb3..20131aa 100644
--- a/sys/dev/ixgbe/ixv.c
+++ b/sys/dev/ixgbe/ixv.c
@@ -1686,37 +1686,35 @@ static int
 ixv_setup_msix(struct adapter *adapter)
 {
 	device_t dev = adapter->dev;
-	int rid, vectors, want = 2;
+	int rid, want;
 
 
 	/* First try MSI/X */
 	rid = PCIR_BAR(3);
 	adapter->msix_mem = bus_alloc_resource_any(dev,
 	    SYS_RES_MEMORY, &rid, RF_ACTIVE);
-       	if (!adapter->msix_mem) {
+       	if (adapter->msix_mem == NULL) {
 		device_printf(adapter->dev,
 		    "Unable to map MSIX table \n");
 		goto out;
 	}
 
-	vectors = pci_msix_count(dev); 
-	if (vectors < 2) {
-		bus_release_resource(dev, SYS_RES_MEMORY,
-		    rid, adapter->msix_mem);
-		adapter->msix_mem = NULL;
-		goto out;
-	}
-
 	/*
 	** Want two vectors: one for a queue,
 	** plus an additional for mailbox.
 	*/
+	want = 2;
 	if (pci_alloc_msix(dev, &want) == 0) {
                	device_printf(adapter->dev,
 		    "Using MSIX interrupts with %d vectors\n", want);
 		return (want);
 	}
 out:
+       	if (adapter->msix_mem != NULL) {
+		bus_release_resource(dev, SYS_RES_MEMORY,
+		    rid, adapter->msix_mem);
+		adapter->msix_mem = NULL;
+	}
 	device_printf(adapter->dev,"MSIX config error\n");
 	return (ENXIO);
 }