From c8a53736fe9139a202d17ed7f95389d33326cb61 Mon Sep 17 00:00:00 2001
From: jfv <jfv@FreeBSD.org>
Date: Mon, 12 Aug 2013 22:54:38 +0000
Subject: Improve the MSIX setup code in the drivers, thanks to Marius for the
 changes. Make sure that pci_alloc_msix() does give us the vectors we need and
 fall back to MSI when it doesn't, also release any that were allocated when
 insufficient.

MFC after: 3 days
---
 sys/dev/e1000/if_em.c  | 21 ++++++++++++++-------
 sys/dev/e1000/if_igb.c | 13 +++++++++----
 sys/dev/ixgbe/ixgbe.c  |  8 +++++++-
 sys/dev/ixgbe/ixv.c    |  4 +++-
 4 files changed, 33 insertions(+), 13 deletions(-)

(limited to 'sys/dev')

diff --git a/sys/dev/e1000/if_em.c b/sys/dev/e1000/if_em.c
index 9499953..b3327e8 100644
--- a/sys/dev/e1000/if_em.c
+++ b/sys/dev/e1000/if_em.c
@@ -2277,7 +2277,7 @@ em_local_timer(void *arg)
 
 	/* Mask to use in the irq trigger */
 	if (adapter->msix_mem)
-		trigger = rxr->ims; /* RX for 82574 */
+		trigger = rxr->ims;
 	else
 		trigger = E1000_ICS_RXDMT0;
 
@@ -2775,23 +2775,30 @@ em_setup_msix(struct adapter *adapter)
 		if (val >= 3)
 			val = 3;
 		else {
-			bus_release_resource(dev, SYS_RES_MEMORY,
-			    PCIR_BAR(EM_MSIX_BAR), adapter->msix_mem);
-			adapter->msix_mem = NULL;
                		device_printf(adapter->dev,
-			    "MSIX: incorrect vectors, using MSI\n");
+			    "MSIX: insufficient vectors, using MSI\n");
 			goto msi;
 		}
 
-		if (pci_alloc_msix(dev, &val) == 0) {
+		if ((pci_alloc_msix(dev, &val) == 0) && (val == 3)) {
 			device_printf(adapter->dev,
 			    "Using MSIX interrupts "
 			    "with %d vectors\n", val);
 			return (val);
 		}
-		/* Fall through to MSI */
+
+		/*
+		** If MSIX alloc failed or provided us with
+		** less than needed, free and fall through to MSI
+		*/
+		pci_release_msi(dev);
 	}
 msi:
+	if (adapter->msix_mem != NULL) {
+		bus_release_resource(dev, SYS_RES_MEMORY,
+		    PCIR_BAR(EM_MSIX_BAR), adapter->msix_mem);
+		adapter->msix_mem = NULL;
+	}
        	val = 1;
        	if (pci_alloc_msi(dev, &val) == 0) {
                	device_printf(adapter->dev,"Using an MSI interrupt\n");
diff --git a/sys/dev/e1000/if_igb.c b/sys/dev/e1000/if_igb.c
index d524832..cb079fa 100644
--- a/sys/dev/e1000/if_igb.c
+++ b/sys/dev/e1000/if_igb.c
@@ -2899,13 +2899,18 @@ igb_setup_msix(struct adapter *adapter)
 		    msgs, want);
 		goto msi;
 	}
-	if (pci_alloc_msix(dev, &msgs) == 0) {
+	if ((pci_alloc_msix(dev, &msgs) == 0) && (msgs == want)) {
                	device_printf(adapter->dev,
 		    "Using MSIX interrupts with %d vectors\n", msgs);
 		adapter->num_queues = queues;
 		return (msgs);
 	}
-	/* Fallback to MSI configuration */
+	/*
+	** If MSIX alloc failed or provided us with
+	** less than needed, free and fall through to MSI
+	*/
+	pci_release_msi(dev);
+
 msi:
        	if (adapter->msix_mem != NULL) {
 		bus_release_resource(dev, SYS_RES_MEMORY,
@@ -2914,10 +2919,10 @@ msi:
 	}
        	msgs = 1;
 	if (pci_alloc_msi(dev, &msgs) == 0) {
-		device_printf(adapter->dev," Using MSI interrupt\n");
+		device_printf(adapter->dev," Using an MSI interrupt\n");
 		return (msgs);
 	}
-	/* Default to a legacy interrupt */
+	device_printf(adapter->dev," Using a Legacy interrupt\n");
 	return (0);
 }
 
diff --git a/sys/dev/ixgbe/ixgbe.c b/sys/dev/ixgbe/ixgbe.c
index ca4aa66..e6dc239 100644
--- a/sys/dev/ixgbe/ixgbe.c
+++ b/sys/dev/ixgbe/ixgbe.c
@@ -2456,12 +2456,18 @@ ixgbe_setup_msix(struct adapter *adapter)
 		    msgs, want);
 		goto msi;
 	}
-	if (pci_alloc_msix(dev, &msgs) == 0) {
+	if ((pci_alloc_msix(dev, &msgs) == 0) && (msgs == want)) {
                	device_printf(adapter->dev,
 		    "Using MSIX interrupts with %d vectors\n", msgs);
 		adapter->num_queues = queues;
 		return (msgs);
 	}
+	/*
+	** If MSIX alloc failed or provided us with
+	** less than needed, free and fall through to MSI
+	*/
+	pci_release_msi(dev);
+
 msi:
        	if (adapter->msix_mem != NULL) {
 		bus_release_resource(dev, SYS_RES_MEMORY,
diff --git a/sys/dev/ixgbe/ixv.c b/sys/dev/ixgbe/ixv.c
index 20131aa..c0cd7ae 100644
--- a/sys/dev/ixgbe/ixv.c
+++ b/sys/dev/ixgbe/ixv.c
@@ -1704,11 +1704,13 @@ ixv_setup_msix(struct adapter *adapter)
 	** plus an additional for mailbox.
 	*/
 	want = 2;
-	if (pci_alloc_msix(dev, &want) == 0) {
+	if ((pci_alloc_msix(dev, &want) == 0) && (want == 2)) {
                	device_printf(adapter->dev,
 		    "Using MSIX interrupts with %d vectors\n", want);
 		return (want);
 	}
+	/* Release in case alloc was insufficient */
+	pci_release_msi(dev);
 out:
        	if (adapter->msix_mem != NULL) {
 		bus_release_resource(dev, SYS_RES_MEMORY,
-- 
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