--- //depot/projects/smpng/sys/dev/pci/pci.c	2006/12/12 19:41:57
+++ //depot/user/jhb/msi/dev/pci/pci.c	2006/12/12 19:59:13
@@ -165,6 +165,7 @@
 	uint32_t devid;	/* Vendor/device of the card */
 	int	type;
 #define PCI_QUIRK_MAP_REG	1 /* PCI map register in weird place */
+#define	PCI_QUIRK_DISABLE_MSI	2 /* MSI/MSI-X doesn't work */
 	int	arg1;
 	int	arg2;
 };
@@ -176,6 +177,24 @@
 	/* As does the Serverworks OSB4 (the SMBus mapping register) */
 	{ 0x02001166, PCI_QUIRK_MAP_REG,	0x90,	 0 },
 
+	/*
+	 * MSI doesn't work with the Intel E7500 chipset, at least on
+	 * the XXXX system.
+	 */
+	{ 0x25408086, PCI_QUIRK_DISABLE_MSI,	0,	0 },
+
+	/*
+	 * MSI doesn't work with the Intel E7501 chipset, at least on
+	 * the Tyan 2721 motherboard.
+	 */
+	{ 0x254c8086, PCI_QUIRK_DISABLE_MSI,	0,	0 },
+
+	/*
+	 * MSI doesn't work with devices behind the AMD 8131 HT-PCIX
+	 * bridge.
+	 */
+	{ 0x74501022, PCI_QUIRK_DISABLE_MSI,	0,	0 },
+
 	{ 0 }
 };
 
@@ -224,6 +243,11 @@
 SYSCTL_INT(_hw_pci, OID_AUTO, enable_msix, CTLFLAG_RW, &pci_do_msix, 1,
     "Enable support for MSI-X interrupts");
 
+static int pci_honor_msi_blacklist = 1;
+TUNABLE_INT("hw.pci.honor_msi_blacklist", &pci_honor_msi_blacklist);
+SYSCTL_INT(_hw_pci, OID_AUTO, honor_msi_blacklist, CTLFLAG_RD,
+    &pci_honor_msi_blacklist, 1, "Honor chipset blacklist for MSI");
+
 /* Find a device_t by bus/slot/function */
 
 device_t
@@ -1195,6 +1225,47 @@
 }
 
 /*
+ * Returns true if the specified device is blacklisted because MSI
+ * doesn't work.
+ */
+int
+pci_msi_device_blacklisted(device_t dev)
+{
+	struct pci_quirk *q;
+
+	if (!pci_honor_msi_blacklist)
+		return (0);
+
+	for (q = &pci_quirks[0]; q->devid; q++) {
+		if (q->devid == pci_get_devid(dev) &&
+		    q->type == PCI_QUIRK_DISABLE_MSI)
+			return (1);
+	}
+	return (0);
+}
+
+/*
+ * Determine if MSI is blacklisted globally on this sytem.  Currently,
+ * we just check for blacklisted chipsets as represented by the
+ * host-PCI bridge at device 0:0:0.  In the future, it may become
+ * necessary to check other system attributes, such as the kenv values
+ * that give the motherboard manufacturer and model number.
+ */
+static int
+pci_msi_blacklisted(void)
+{
+	device_t dev;
+
+	if (!pci_honor_msi_blacklist)
+		return (0);
+
+	dev = pci_find_bsf(0, 0, 0);
+	if (dev != NULL)
+		return (pci_msi_device_blacklisted(dev));
+	return (0);
+}
+
+/*
  * Attempt to allocate *count MSI messages.  The actual number allocated is
  * returned in *count.  After this function returns, each message will be
  * available to the driver as SYS_RES_IRQ resources starting at a rid 1.
@@ -1217,6 +1288,10 @@
 	if (rle != NULL && rle->res != NULL)
 		return (ENXIO);
 
+	/* If MSI is blacklisted for this system, fail. */
+	if (pci_msi_blacklisted())
+		return (ENXIO);
+
 	/* Try MSI-X first. */
 	error = pci_alloc_msix(dev, child, count);
 	if (error != ENODEV)
--- //depot/projects/smpng/sys/dev/pci/pci_pci.c	2006/11/13 22:08:01
+++ //depot/user/jhb/msi/dev/pci/pci_pci.c	2006/12/12 17:52:17
@@ -240,6 +240,9 @@
 	}
     }
 
+    if (pci_msi_device_blacklisted(dev))
+	sc->flags |= PCIB_DISABLE_MSI;
+
     /*
      * Intel 815, 845 and other chipsets say they are PCI-PCI bridges,
      * but have a ProgIF of 0x80.  The 82801 family (AA, AB, BAM/CAM,
@@ -547,8 +550,11 @@
 int
 pcib_alloc_msi(device_t pcib, device_t dev, int count, int maxcount, int *irqs)
 {
+	struct pcib_softc *sc = device_get_softc(dev);
 	device_t bus;
 
+	if (sc->flags & PCIB_DISABLE_MSI)
+		return (ENXIO);
 	bus = device_get_parent(pcib);
 	return (PCIB_ALLOC_MSI(device_get_parent(bus), dev, count, maxcount,
 	    irqs));
@@ -568,8 +574,11 @@
 int
 pcib_alloc_msix(device_t pcib, device_t dev, int index, int *irq)
 {
+	struct pcib_softc *sc = device_get_softc(dev);
 	device_t bus;
 
+	if (sc->flags & PCIB_DISABLE_MSI)
+		return (ENXIO);
 	bus = device_get_parent(pcib);
 	return (PCIB_ALLOC_MSIX(device_get_parent(bus), dev, index, irq));
 }
--- //depot/projects/smpng/sys/dev/pci/pcib_private.h	2006/11/13 22:08:01
+++ //depot/user/jhb/msi/dev/pci/pcib_private.h	2006/11/29 21:34:00
@@ -46,6 +46,7 @@
     device_t	dev;
     uint32_t	flags;		/* flags */
 #define PCIB_SUBTRACTIVE	0x1
+#define	PCIB_DISABLE_MSI	0x2
     uint16_t	command;	/* command register */
     uint8_t	secbus;		/* secondary bus number */
     uint8_t	subbus;		/* subordinate bus number */
--- //depot/projects/smpng/sys/dev/pci/pcivar.h	2006/11/15 21:39:52
+++ //depot/user/jhb/msi/dev/pci/pcivar.h	2006/12/12 17:52:17
@@ -417,6 +417,7 @@
 void	pci_mask_msix(device_t dev, u_int index);
 int	pci_pending_msix(device_t dev, u_int index);
 void	pci_unmask_msix(device_t dev, u_int index);
+int	pci_msi_device_blacklisted(device_t dev);
 
 #endif	/* _SYS_BUS_H_ */