From f0731c1e48b5fcc4040fc3922524bdb6ba4af230 Mon Sep 17 00:00:00 2001
From: Sascha Wildner <saw@online.de>
Date: Sat, 21 Jul 2012 20:43:31 +0200
Subject: [PATCH] mpt(4): Use MSI on SAS adapters that support it.

The hw.mpt.msi.enable tunable can be used to override this behavior.

Tested-by: ftigeot
---
 share/man/man4/mpt.4       |  8 +++++++-
 sys/dev/disk/mpt/mpt.h     |  3 +++
 sys/dev/disk/mpt/mpt_pci.c | 23 +++++++++++------------
 3 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/share/man/man4/mpt.4 b/share/man/man4/mpt.4
index 3e8a052134..d7b420b363 100644
--- a/share/man/man4/mpt.4
+++ b/share/man/man4/mpt.4
@@ -35,7 +35,7 @@
 .\"
 .\" $FreeBSD: src/share/man/man4/mpt.4,v 1.22 2011/07/23 22:55:32 gjb Exp $
 .\"
-.Dd November 28, 2011
+.Dd July 21, 2012
 .Dt MPT 4
 .Os
 .Sh NAME
@@ -66,6 +66,12 @@ for the LSI Logic Fusion-MPT family of
 and
 .Tn SAS
 controllers.
+.Sh LOADER TUNABLES
+.Bl -tag -width indent
+.It Va hw.mpt.msi.enable
+This tunable specifies whether MSI will be used or not, provided the
+controller supports it.
+By default, the driver will use MSI for SAS adapters.
 .Sh HARDWARE
 The following controllers are supported by the
 .Nm
diff --git a/sys/dev/disk/mpt/mpt.h b/sys/dev/disk/mpt/mpt.h
index f8bff271c5..3f27ca581a 100644
--- a/sys/dev/disk/mpt/mpt.h
+++ b/sys/dev/disk/mpt/mpt.h
@@ -644,7 +644,10 @@ struct mpt_softc {
 	/*
 	 * PCI Hardware info
 	 */
+#ifdef OLD_MSI
 	int			pci_msi_count;
+#endif
+	int			irq_type;	/* Interrupt type */
 	struct resource *	pci_irq;	/* Interrupt map for chip */
 	void *			ih;		/* Interrupt handle */
 #if 0
diff --git a/sys/dev/disk/mpt/mpt_pci.c b/sys/dev/disk/mpt/mpt_pci.c
index cec8dc0432..ae8f8cade4 100644
--- a/sys/dev/disk/mpt/mpt_pci.c
+++ b/sys/dev/disk/mpt/mpt_pci.c
@@ -256,6 +256,7 @@ static void
 mpt_set_options(struct mpt_softc *mpt)
 {
 	int bitmap;
+	int tval;
 
 	bitmap = 0;
 	if (kgetenv_int("mpt_disable", &bitmap)) {
@@ -310,7 +311,12 @@ mpt_set_options(struct mpt_softc *mpt)
 		}
 		mpt->do_cfg_role = 1;
 	}
+	tval = 0;
 	mpt->msi_enable = 0;
+	if (mpt->is_sas)
+		mpt->msi_enable = 1;
+	if (kgetenv_int("hw.mpt.msi.enable", &tval))
+		mpt->msi_enable = tval;
 }
 
 static void
@@ -359,6 +365,7 @@ mpt_pci_attach(device_t dev)
 	int		  iqd;
 	uint32_t	  data, cmd;
 	int		  mpt_io_bar, mpt_mem_bar;
+	u_int		  irq_flags;
 
 	mpt  = (struct mpt_softc*)device_get_softc(dev);
 
@@ -519,18 +526,12 @@ mpt_pci_attach(device_t dev)
 				mpt->pci_msi_count = 0;
 			}
 		}
-		if (iqd == 0 && pci_msi_count(dev) == 1) {
-			mpt->pci_msi_count = 1;
-			if (pci_alloc_msi(dev, &mpt->pci_msi_count) == 0) {
-				iqd = 1;
-			} else {
-				mpt->pci_msi_count = 0;
-			}
-		}
 	}
 #endif
+	mpt->irq_type = pci_alloc_1intr(dev, mpt->msi_enable, &iqd,
+	    &irq_flags);
 	mpt->pci_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &iqd,
-	    RF_ACTIVE | (mpt->pci_msi_count ? 0 : RF_SHAREABLE));
+	    irq_flags);
 	if (mpt->pci_irq == NULL) {
 		device_printf(dev, "could not allocate interrupt\n");
 		goto bad;
@@ -626,10 +627,8 @@ mpt_free_bus_resources(struct mpt_softc *mpt)
 		mpt->pci_irq = NULL;
 	}
 
-	if (mpt->pci_msi_count) {
+	if (mpt->irq_type == PCI_INTR_TYPE_MSI)
 		pci_release_msi(mpt->dev);
-		mpt->pci_msi_count = 0;
-	}
 
 	if (mpt->pci_pio_reg) {
 		bus_release_resource(mpt->dev, SYS_RES_IOPORT,
-- 
2.41.0