Merge branch 'pci/msi' into next

* pci/msi:
  PCI/MSI: Remove unnecessary temporary variable
  PCI/MSI: Use __write_msi_msg() instead of write_msi_msg()
  MSI/powerpc: Use __read_msi_msg() instead of read_msi_msg()
  PCI/MSI: Use __get_cached_msi_msg() instead of get_cached_msi_msg()
  PCI/MSI: Add "msi_bus" sysfs MSI/MSI-X control for endpoints
  PCI/MSI: Remove "pos" from the struct msi_desc msi_attrib
  PCI/MSI: Remove unused kobject from struct msi_desc
  PCI/MSI: Rename pci_msi_check_device() to pci_msi_supported()
  PCI/MSI: Move D0 check into pci_msi_check_device()
  PCI/MSI: Remove arch_msi_check_device()
  irqchip: armada-370-xp: Remove arch_msi_check_device()
  PCI/MSI/PPC: Remove arch_msi_check_device()

Conflicts:
	drivers/pci/host/pcie-designware.c

Documentation/ABI/testing/sysfs-bus-pci

@@ -65,6 +65,16 @@ Description:
 		force a rescan of all PCI buses in the system, and
 		re-discover previously removed devices.
 
+What:		/sys/bus/pci/devices/.../msi_bus
+Date:		September 2014
+Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
+Description:
+		Writing a zero value to this attribute disallows MSI and
+		MSI-X for any future drivers of the device.  If the device
+		is a bridge, MSI and MSI-X will be disallowed for future
+		drivers of all child devices under the bridge.  Drivers
+		must be reloaded for the new setting to take effect.
+
 What:		/sys/bus/pci/devices/.../msi_irqs/
 Date:		September, 2011
 Contact:	Neil Horman <nhorman@tuxdriver.com>

arch/ia64/kernel/msi_ia64.c

@@ -23,7 +23,7 @@ static int ia64_set_msi_irq_affinity(struct irq_data *idata,
 	if (irq_prepare_move(irq, cpu))
 		return -1;
 
-	get_cached_msi_msg(irq, &msg);
+	__get_cached_msi_msg(idata->msi_desc, &msg);
 
 	addr = msg.address_lo;
 	addr &= MSI_ADDR_DEST_ID_MASK;

arch/ia64/sn/kernel/msi_sn.c

@@ -175,7 +175,7 @@ static int sn_set_msi_irq_affinity(struct irq_data *data,
 	 * Release XIO resources for the old MSI PCI address
 	 */
 
-	get_cached_msi_msg(irq, &msg);
+	__get_cached_msi_msg(data->msi_desc, &msg);
 	sn_pdev = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
 	pdev = sn_pdev->pdi_linux_pcidev;
 	provider = SN_PCIDEV_BUSPROVIDER(pdev);

arch/mips/pci/msi-octeon.c

@@ -73,8 +73,7 @@ int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
 	 * wants.  Most devices only want 1, which will give
 	 * configured_private_bits and request_private_bits equal 0.
 	 */
-	pci_read_config_word(dev, desc->msi_attrib.pos + PCI_MSI_FLAGS,
+	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
-			     &control);
 
 	/*
 	 * If the number of private bits has been configured then use
@@ -176,8 +175,7 @@ msi_irq_allocated:
 	/* Update the number of IRQs the device has available to it */
 	control &= ~PCI_MSI_FLAGS_QSIZE;
 	control |= request_private_bits << 4;
-	pci_write_config_word(dev, desc->msi_attrib.pos + PCI_MSI_FLAGS,
+	pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
-			      control);
 
 	irq_set_msi_desc(irq, desc);
 	write_msi_msg(irq, &msg);

arch/powerpc/include/asm/machdep.h

@@ -136,8 +136,6 @@ struct machdep_calls {
 	int		(*pci_setup_phb)(struct pci_controller *host);
 
 #ifdef CONFIG_PCI_MSI
-	int		(*msi_check_device)(struct pci_dev* dev,
-					    int nvec, int type);
 	int		(*setup_msi_irqs)(struct pci_dev *dev,
 					  int nvec, int type);
 	void		(*teardown_msi_irqs)(struct pci_dev *dev);

arch/powerpc/kernel/msi.c

@@ -13,7 +13,7 @@
 
 #include <asm/machdep.h>
 
-int arch_msi_check_device(struct pci_dev* dev, int nvec, int type)
+int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 {
 	if (!ppc_md.setup_msi_irqs || !ppc_md.teardown_msi_irqs) {
 		pr_debug("msi: Platform doesn't provide MSI callbacks.\n");
@@ -24,16 +24,6 @@ int arch_msi_check_device(struct pci_dev* dev, int nvec, int type)
 	if (type == PCI_CAP_ID_MSI && nvec > 1)
 		return 1;
 
-	if (ppc_md.msi_check_device) {
-		pr_debug("msi: Using platform check routine.\n");
-		return ppc_md.msi_check_device(dev, nvec, type);
-	}
-
-        return 0;
-}
-
-int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
-{
 	return ppc_md.setup_msi_irqs(dev, nvec, type);
 }
 

arch/powerpc/platforms/cell/axon_msi.c

@@ -199,14 +199,6 @@ out_error:
 	return msic;
 }
 
-static int axon_msi_check_device(struct pci_dev *dev, int nvec, int type)
-{
-	if (!find_msi_translator(dev))
-		return -ENODEV;
-
-	return 0;
-}
-
 static int setup_msi_msg_address(struct pci_dev *dev, struct msi_msg *msg)
 {
 	struct device_node *dn;
@@ -416,7 +408,6 @@ static int axon_msi_probe(struct platform_device *device)
 
 	ppc_md.setup_msi_irqs = axon_msi_setup_msi_irqs;
 	ppc_md.teardown_msi_irqs = axon_msi_teardown_msi_irqs;
-	ppc_md.msi_check_device = axon_msi_check_device;
 
 	axon_msi_debug_setup(dn, msic);
 

arch/powerpc/platforms/powernv/pci.c

@@ -46,29 +46,21 @@
 //#define cfg_dbg(fmt...)	printk(fmt)
 
 #ifdef CONFIG_PCI_MSI
-static int pnv_msi_check_device(struct pci_dev* pdev, int nvec, int type)
-{
-	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
-	struct pnv_phb *phb = hose->private_data;
-	struct pci_dn *pdn = pci_get_pdn(pdev);
-
-	if (pdn && pdn->force_32bit_msi && !phb->msi32_support)
-		return -ENODEV;
-
-	return (phb && phb->msi_bmp.bitmap) ? 0 : -ENODEV;
-}
-
 static int pnv_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 {
 	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
 	struct pnv_phb *phb = hose->private_data;
+	struct pci_dn *pdn = pci_get_pdn(pdev);
 	struct msi_desc *entry;
 	struct msi_msg msg;
 	int hwirq;
 	unsigned int virq;
 	int rc;
 
-	if (WARN_ON(!phb))
+	if (WARN_ON(!phb) || !phb->msi_bmp.bitmap)
+		return -ENODEV;
+
+	if (pdn && pdn->force_32bit_msi && !phb->msi32_support)
 		return -ENODEV;
 
 	list_for_each_entry(entry, &pdev->msi_list, list) {
@@ -860,7 +852,6 @@ void __init pnv_pci_init(void)
 
 	/* Configure MSIs */
 #ifdef CONFIG_PCI_MSI
-	ppc_md.msi_check_device = pnv_msi_check_device;
 	ppc_md.setup_msi_irqs = pnv_setup_msi_irqs;
 	ppc_md.teardown_msi_irqs = pnv_teardown_msi_irqs;
 #endif

arch/powerpc/platforms/pseries/msi.c

@@ -336,26 +336,6 @@ out:
 	return request;
 }
 
-static int rtas_msi_check_device(struct pci_dev *pdev, int nvec, int type)
-{
-	int quota, rc;
-
-	if (type == PCI_CAP_ID_MSIX)
-		rc = check_req_msix(pdev, nvec);
-	else
-		rc = check_req_msi(pdev, nvec);
-
-	if (rc)
-		return rc;
-
-	quota = msi_quota_for_device(pdev, nvec);
-
-	if (quota && quota < nvec)
-		return quota;
-
-	return 0;
-}
-
 static int check_msix_entries(struct pci_dev *pdev)
 {
 	struct msi_desc *entry;
@@ -397,15 +377,24 @@ static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev)
 static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type)
 {
 	struct pci_dn *pdn;
-	int hwirq, virq, i, rc;
+	int hwirq, virq, i, quota, rc;
 	struct msi_desc *entry;
 	struct msi_msg msg;
 	int nvec = nvec_in;
 	int use_32bit_msi_hack = 0;
 
-	pdn = pci_get_pdn(pdev);
+	if (type == PCI_CAP_ID_MSIX)
-	if (!pdn)
+		rc = check_req_msix(pdev, nvec);
-		return -ENODEV;
+	else
+		rc = check_req_msi(pdev, nvec);
+
+	if (rc)
+		return rc;
+
+	quota = msi_quota_for_device(pdev, nvec);
+
+	if (quota && quota < nvec)
+		return quota;
 
 	if (type == PCI_CAP_ID_MSIX && check_msix_entries(pdev))
 		return -EINVAL;
@@ -416,12 +405,14 @@ static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type)
 	 */
 	if (type == PCI_CAP_ID_MSIX) {
 		int m = roundup_pow_of_two(nvec);
-		int quota = msi_quota_for_device(pdev, m);
+		quota = msi_quota_for_device(pdev, m);
 
 		if (quota >= m)
 			nvec = m;
 	}
 
+	pdn = pci_get_pdn(pdev);
+
 	/*
 	 * Try the new more explicit firmware interface, if that fails fall
 	 * back to the old interface. The old interface is known to never
@@ -485,7 +476,7 @@ again:
 		irq_set_msi_desc(virq, entry);
 
 		/* Read config space back so we can restore after reset */
-		read_msi_msg(virq, &msg);
+		__read_msi_msg(entry, &msg);
 		entry->msg = msg;
 	}
 
@@ -526,7 +517,6 @@ static int rtas_msi_init(void)
 	WARN_ON(ppc_md.setup_msi_irqs);
 	ppc_md.setup_msi_irqs = rtas_setup_msi_irqs;
 	ppc_md.teardown_msi_irqs = rtas_teardown_msi_irqs;
-	ppc_md.msi_check_device = rtas_msi_check_device;
 
 	WARN_ON(ppc_md.pci_irq_fixup);
 	ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup;

arch/powerpc/sysdev/fsl_msi.c

@@ -109,14 +109,6 @@ static int fsl_msi_init_allocator(struct fsl_msi *msi_data)
 	return 0;
 }
 
-static int fsl_msi_check_device(struct pci_dev *pdev, int nvec, int type)
-{
-	if (type == PCI_CAP_ID_MSIX)
-		pr_debug("fslmsi: MSI-X untested, trying anyway.\n");
-
-	return 0;
-}
-
 static void fsl_teardown_msi_irqs(struct pci_dev *pdev)
 {
 	struct msi_desc *entry;
@@ -173,6 +165,9 @@ static int fsl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 	struct msi_msg msg;
 	struct fsl_msi *msi_data;
 
+	if (type == PCI_CAP_ID_MSIX)
+		pr_debug("fslmsi: MSI-X untested, trying anyway.\n");
+
 	/*
 	 * If the PCI node has an fsl,msi property, then we need to use it
 	 * to find the specific MSI.
@@ -527,7 +522,6 @@ static int fsl_of_msi_probe(struct platform_device *dev)
 	if (!ppc_md.setup_msi_irqs) {
 		ppc_md.setup_msi_irqs = fsl_setup_msi_irqs;
 		ppc_md.teardown_msi_irqs = fsl_teardown_msi_irqs;
-		ppc_md.msi_check_device = fsl_msi_check_device;
 	} else if (ppc_md.setup_msi_irqs != fsl_setup_msi_irqs) {
 		dev_err(&dev->dev, "Different MSI driver already installed!\n");
 		err = -ENODEV;

arch/powerpc/sysdev/mpic_pasemi_msi.c

@@ -63,14 +63,6 @@ static struct irq_chip mpic_pasemi_msi_chip = {
 	.name			= "PASEMI-MSI",
 };
 
-static int pasemi_msi_check_device(struct pci_dev *pdev, int nvec, int type)
-{
-	if (type == PCI_CAP_ID_MSIX)
-		pr_debug("pasemi_msi: MSI-X untested, trying anyway\n");
-
-	return 0;
-}
-
 static void pasemi_msi_teardown_msi_irqs(struct pci_dev *pdev)
 {
 	struct msi_desc *entry;
@@ -97,6 +89,8 @@ static int pasemi_msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 	struct msi_msg msg;
 	int hwirq;
 
+	if (type == PCI_CAP_ID_MSIX)
+		pr_debug("pasemi_msi: MSI-X untested, trying anyway\n");
 	pr_debug("pasemi_msi_setup_msi_irqs, pdev %p nvec %d type %d\n",
 		 pdev, nvec, type);
 
@@ -169,7 +163,6 @@ int mpic_pasemi_msi_init(struct mpic *mpic)
 	WARN_ON(ppc_md.setup_msi_irqs);
 	ppc_md.setup_msi_irqs = pasemi_msi_setup_msi_irqs;
 	ppc_md.teardown_msi_irqs = pasemi_msi_teardown_msi_irqs;
-	ppc_md.msi_check_device = pasemi_msi_check_device;
 
 	return 0;
 }

arch/powerpc/sysdev/mpic_u3msi.c

@@ -105,22 +105,6 @@ static u64 find_u4_magic_addr(struct pci_dev *pdev, unsigned int hwirq)
 	return 0;
 }
 
-static int u3msi_msi_check_device(struct pci_dev *pdev, int nvec, int type)
-{
-	if (type == PCI_CAP_ID_MSIX)
-		pr_debug("u3msi: MSI-X untested, trying anyway.\n");
-
-	/* If we can't find a magic address then MSI ain't gonna work */
-	if (find_ht_magic_addr(pdev, 0) == 0 &&
-	    find_u4_magic_addr(pdev, 0) == 0) {
-		pr_debug("u3msi: no magic address found for %s\n",
-			 pci_name(pdev));
-		return -ENXIO;
-	}
-
-	return 0;
-}
-
 static void u3msi_teardown_msi_irqs(struct pci_dev *pdev)
 {
 	struct msi_desc *entry;
@@ -146,6 +130,17 @@ static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 	u64 addr;
 	int hwirq;
 
+	if (type == PCI_CAP_ID_MSIX)
+		pr_debug("u3msi: MSI-X untested, trying anyway.\n");
+
+	/* If we can't find a magic address then MSI ain't gonna work */
+	if (find_ht_magic_addr(pdev, 0) == 0 &&
+	    find_u4_magic_addr(pdev, 0) == 0) {
+		pr_debug("u3msi: no magic address found for %s\n",
+			 pci_name(pdev));
+		return -ENXIO;
+	}
+
 	list_for_each_entry(entry, &pdev->msi_list, list) {
 		hwirq = msi_bitmap_alloc_hwirqs(&msi_mpic->msi_bitmap, 1);
 		if (hwirq < 0) {
@@ -202,7 +197,6 @@ int mpic_u3msi_init(struct mpic *mpic)
 	WARN_ON(ppc_md.setup_msi_irqs);
 	ppc_md.setup_msi_irqs = u3msi_setup_msi_irqs;
 	ppc_md.teardown_msi_irqs = u3msi_teardown_msi_irqs;
-	ppc_md.msi_check_device = u3msi_msi_check_device;
 
 	return 0;
 }

arch/powerpc/sysdev/ppc4xx_hsta_msi.c

@@ -44,6 +44,12 @@ static int hsta_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 	int irq, hwirq;
 	u64 addr;
 
+	/* We don't support MSI-X */
+	if (type == PCI_CAP_ID_MSIX) {
+		pr_debug("%s: MSI-X not supported.\n", __func__);
+		return -EINVAL;
+	}
+
 	list_for_each_entry(entry, &dev->msi_list, list) {
 		irq = msi_bitmap_alloc_hwirqs(&ppc4xx_hsta_msi.bmp, 1);
 		if (irq < 0) {
@@ -117,17 +123,6 @@ static void hsta_teardown_msi_irqs(struct pci_dev *dev)
 	}
 }
 
-static int hsta_msi_check_device(struct pci_dev *pdev, int nvec, int type)
-{
-	/* We don't support MSI-X */
-	if (type == PCI_CAP_ID_MSIX) {
-		pr_debug("%s: MSI-X not supported.\n", __func__);
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
 static int hsta_msi_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -178,7 +173,6 @@ static int hsta_msi_probe(struct platform_device *pdev)
 
 	ppc_md.setup_msi_irqs = hsta_setup_msi_irqs;
 	ppc_md.teardown_msi_irqs = hsta_teardown_msi_irqs;
-	ppc_md.msi_check_device = hsta_msi_check_device;
 	return 0;
 
 out2:

arch/powerpc/sysdev/ppc4xx_msi.c

@@ -85,8 +85,12 @@ static int ppc4xx_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 	struct msi_desc *entry;
 	struct ppc4xx_msi *msi_data = &ppc4xx_msi;
 
-	msi_data->msi_virqs = kmalloc((msi_irqs) * sizeof(int),
+	dev_dbg(&dev->dev, "PCIE-MSI:%s called. vec %x type %d\n",
-					    GFP_KERNEL);
+		__func__, nvec, type);
+	if (type == PCI_CAP_ID_MSIX)
+		pr_debug("ppc4xx msi: MSI-X untested, trying anyway.\n");
+
+	msi_data->msi_virqs = kmalloc((msi_irqs) * sizeof(int), GFP_KERNEL);
 	if (!msi_data->msi_virqs)
 		return -ENOMEM;
 
@@ -134,16 +138,6 @@ void ppc4xx_teardown_msi_irqs(struct pci_dev *dev)
 	}
 }
 
-static int ppc4xx_msi_check_device(struct pci_dev *pdev, int nvec, int type)
-{
-	dev_dbg(&pdev->dev, "PCIE-MSI:%s called. vec %x type %d\n",
-		__func__, nvec, type);
-	if (type == PCI_CAP_ID_MSIX)
-		pr_debug("ppc4xx msi: MSI-X untested, trying anyway.\n");
-
-	return 0;
-}
-
 static int ppc4xx_setup_pcieh_hw(struct platform_device *dev,
 				 struct resource res, struct ppc4xx_msi *msi)
 {
@@ -259,7 +253,6 @@ static int ppc4xx_msi_probe(struct platform_device *dev)
 
 	ppc_md.setup_msi_irqs = ppc4xx_setup_msi_irqs;
 	ppc_md.teardown_msi_irqs = ppc4xx_teardown_msi_irqs;
-	ppc_md.msi_check_device = ppc4xx_msi_check_device;
 	return err;
 
 error_out:

drivers/irqchip/irq-armada-370-xp.c

@@ -136,6 +136,10 @@ static int armada_370_xp_setup_msi_irq(struct msi_chip *chip,
 	struct msi_msg msg;
 	int virq, hwirq;
 
+	/* We support MSI, but not MSI-X */
+	if (desc->msi_attrib.is_msix)
+		return -EINVAL;
+
 	hwirq = armada_370_xp_alloc_msi();
 	if (hwirq < 0)
 		return hwirq;
@@ -166,15 +170,6 @@ static void armada_370_xp_teardown_msi_irq(struct msi_chip *chip,
 	armada_370_xp_free_msi(hwirq);
 }
 
-static int armada_370_xp_check_msi_device(struct msi_chip *chip, struct pci_dev *dev,
-					  int nvec, int type)
-{
-	/* We support MSI, but not MSI-X */
-	if (type == PCI_CAP_ID_MSI)
-		return 0;
-	return -EINVAL;
-}
-
 static struct irq_chip armada_370_xp_msi_irq_chip = {
 	.name = "armada_370_xp_msi_irq",
 	.irq_enable = unmask_msi_irq,
@@ -213,7 +208,6 @@ static int armada_370_xp_msi_init(struct device_node *node,
 
 	msi_chip->setup_irq = armada_370_xp_setup_msi_irq;
 	msi_chip->teardown_irq = armada_370_xp_teardown_msi_irq;
-	msi_chip->check_device = armada_370_xp_check_msi_device;
 	msi_chip->of_node = node;
 
 	armada_370_xp_msi_domain =

drivers/pci/host/pcie-designware.c

@@ -343,8 +343,7 @@ static int dw_msi_setup_irq(struct msi_chip *chip, struct pci_dev *pdev,
 	struct msi_msg msg;
 	struct pcie_port *pp = sys_to_pcie(pdev->bus->sysdata);
 
-	pci_read_config_word(pdev, desc->msi_attrib.pos+PCI_MSI_FLAGS,
+	pci_read_config_word(pdev, pdev->msi_cap + PCI_MSI_FLAGS, &msg_ctr);
-				&msg_ctr);
 	msgvec = (msg_ctr & PCI_MSI_FLAGS_QSIZE) >> 4;
 	if (msgvec == 0)
 		msgvec = (msg_ctr & PCI_MSI_FLAGS_QMASK) >> 1;

drivers/pci/msi.c

@@ -56,16 +56,6 @@ void __weak arch_teardown_msi_irq(unsigned int irq)
 	chip->teardown_irq(chip, irq);
 }
 
-int __weak arch_msi_check_device(struct pci_dev *dev, int nvec, int type)
-{
-	struct msi_chip *chip = dev->bus->msi;
-
-	if (!chip || !chip->check_device)
-		return 0;
-
-	return chip->check_device(chip, dev, nvec, type);
-}
-
 int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 {
 	struct msi_desc *entry;
@@ -130,7 +120,7 @@ static void default_restore_msi_irq(struct pci_dev *dev, int irq)
 	}
 
 	if (entry)
-		write_msi_msg(irq, &entry->msg);
+		__write_msi_msg(entry, &entry->msg);
 }
 
 void __weak arch_restore_msi_irqs(struct pci_dev *dev)
@@ -384,17 +374,6 @@ static void free_msi_irqs(struct pci_dev *dev)
 				iounmap(entry->mask_base);
 		}
 
-		/*
-		 * Its possible that we get into this path
-		 * When populate_msi_sysfs fails, which means the entries
-		 * were not registered with sysfs.  In that case don't
-		 * unregister them.
-		 */
-		if (entry->kobj.parent) {
-			kobject_del(&entry->kobj);
-			kobject_put(&entry->kobj);
-		}
-
 		list_del(&entry->list);
 		kfree(entry);
 	}
@@ -595,7 +574,6 @@ static struct msi_desc *msi_setup_entry(struct pci_dev *dev)
 	entry->msi_attrib.entry_nr	= 0;
 	entry->msi_attrib.maskbit	= !!(control & PCI_MSI_FLAGS_MASKBIT);
 	entry->msi_attrib.default_irq	= dev->irq;	/* Save IOAPIC IRQ */
-	entry->msi_attrib.pos		= dev->msi_cap;
 	entry->msi_attrib.multi_cap	= (control & PCI_MSI_FLAGS_QMASK) >> 1;
 
 	if (control & PCI_MSI_FLAGS_64BIT)
@@ -699,7 +677,6 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
 		entry->msi_attrib.is_64		= 1;
 		entry->msi_attrib.entry_nr	= entries[i].entry;
 		entry->msi_attrib.default_irq	= dev->irq;
-		entry->msi_attrib.pos		= dev->msix_cap;
 		entry->mask_base		= base;
 
 		list_add_tail(&entry->list, &dev->msi_list);
@@ -806,23 +783,24 @@ out_free:
 }
 
 /**
- * pci_msi_check_device - check whether MSI may be enabled on a device
+ * pci_msi_supported - check whether MSI may be enabled on a device
  * @dev: pointer to the pci_dev data structure of MSI device function
  * @nvec: how many MSIs have been requested ?
- * @type: are we checking for MSI or MSI-X ?
  *
  * Look at global flags, the device itself, and its parent buses
  * to determine if MSI/-X are supported for the device. If MSI/-X is
- * supported return 0, else return an error code.
+ * supported return 1, else return 0.
  **/
-static int pci_msi_check_device(struct pci_dev *dev, int nvec, int type)
+static int pci_msi_supported(struct pci_dev *dev, int nvec)
 {
 	struct pci_bus *bus;
-	int ret;
 
 	/* MSI must be globally enabled and supported by the device */
-	if (!pci_msi_enable || !dev || dev->no_msi)
+	if (!pci_msi_enable)
-		return -EINVAL;
+		return 0;
+
+	if (!dev || dev->no_msi || dev->current_state != PCI_D0)
+		return 0;
 
 	/*
 	 * You can't ask to have 0 or less MSIs configured.
@@ -830,7 +808,7 @@ static int pci_msi_check_device(struct pci_dev *dev, int nvec, int type)
 	 *  b) the list manipulation code assumes nvec >= 1.
 	 */
 	if (nvec < 1)
-		return -ERANGE;
+		return 0;
 
 	/*
 	 * Any bridge which does NOT route MSI transactions from its
@@ -841,13 +819,9 @@ static int pci_msi_check_device(struct pci_dev *dev, int nvec, int type)
 	 */
 	for (bus = dev->bus; bus; bus = bus->parent)
 		if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
-			return -EINVAL;
-
-	ret = arch_msi_check_device(dev, nvec, type);
-	if (ret)
-		return ret;
-
 			return 0;
+
+	return 1;
 }
 
 /**
@@ -946,15 +920,14 @@ EXPORT_SYMBOL(pci_msix_vec_count);
  **/
 int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
 {
-	int status, nr_entries;
+	int nr_entries;
 	int i, j;
 
-	if (!entries || !dev->msix_cap || dev->current_state != PCI_D0)
+	if (!pci_msi_supported(dev, nvec))
 		return -EINVAL;
 
-	status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSIX);
+	if (!entries)
-	if (status)
+		return -EINVAL;
-		return status;
 
 	nr_entries = pci_msix_vec_count(dev);
 	if (nr_entries < 0)
@@ -978,8 +951,7 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
 		dev_info(&dev->dev, "can't enable MSI-X (MSI IRQ already assigned)\n");
 		return -EINVAL;
 	}
-	status = msix_capability_init(dev, entries, nvec);
+	return msix_capability_init(dev, entries, nvec);
-	return status;
 }
 EXPORT_SYMBOL(pci_enable_msix);
 
@@ -1062,7 +1034,7 @@ int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec)
 	int nvec;
 	int rc;
 
-	if (dev->current_state != PCI_D0)
+	if (!pci_msi_supported(dev, minvec))
 		return -EINVAL;
 
 	WARN_ON(!!dev->msi_enabled);
@@ -1085,17 +1057,6 @@ int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec)
 	else if (nvec > maxvec)
 		nvec = maxvec;
 
-	do {
-		rc = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSI);
-		if (rc < 0) {
-			return rc;
-		} else if (rc > 0) {
-			if (rc < minvec)
-				return -ENOSPC;
-			nvec = rc;
-		}
-	} while (rc);
-
 	do {
 		rc = msi_capability_init(dev, nvec);
 		if (rc < 0) {

drivers/pci/pci-sysfs.c

@@ -250,46 +250,45 @@ static ssize_t msi_bus_show(struct device *dev, struct device_attribute *attr,
 			    char *buf)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pci_bus *subordinate = pdev->subordinate;
 
-	if (!pdev->subordinate)
+	return sprintf(buf, "%u\n", subordinate ?
-		return 0;
+		       !(subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI)
-
+			   : !pdev->no_msi);
-	return sprintf(buf, "%u\n",
-		       !(pdev->subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI));
 }
 
 static ssize_t msi_bus_store(struct device *dev, struct device_attribute *attr,
 			     const char *buf, size_t count)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pci_bus *subordinate = pdev->subordinate;
 	unsigned long val;
 
 	if (kstrtoul(buf, 0, &val) < 0)
 		return -EINVAL;
 
-	/*
-	 * Bad things may happen if the no_msi flag is changed
-	 * while drivers are loaded.
-	 */
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
 	/*
-	 * Maybe devices without subordinate buses shouldn't have this
+	 * "no_msi" and "bus_flags" only affect what happens when a driver
-	 * attribute in the first place?
+	 * requests MSI or MSI-X.  They don't affect any drivers that have
+	 * already requested MSI or MSI-X.
 	 */
-	if (!pdev->subordinate)
+	if (!subordinate) {
+		pdev->no_msi = !val;
+		dev_info(&pdev->dev, "MSI/MSI-X %s for future drivers\n",
+			 val ? "allowed" : "disallowed");
 		return count;
-
-	/* Is the flag going to change, or keep the value it already had? */
-	if (!(pdev->subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI) ^
-	    !!val) {
-		pdev->subordinate->bus_flags ^= PCI_BUS_FLAGS_NO_MSI;
-
-		dev_warn(&pdev->dev, "forced subordinate bus to%s support MSI, bad things could happen\n",
-			 val ? "" : " not");
 	}
 
+	if (val)
+		subordinate->bus_flags &= ~PCI_BUS_FLAGS_NO_MSI;
+	else
+		subordinate->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
+
+	dev_info(&subordinate->dev, "MSI/MSI-X %s for future drivers of devices on this bus\n",
+		 val ? "allowed" : "disallowed");
 	return count;
 }
 static DEVICE_ATTR_RW(msi_bus);

include/linux/msi.h

@@ -29,7 +29,6 @@ struct msi_desc {
 		__u8	multi_cap : 3;	/* log2 num of messages supported */
 		__u8	maskbit	: 1;	/* mask-pending bit supported ? */
 		__u8	is_64	: 1;	/* Address size: 0=32bit 1=64bit */
-		__u8	pos;		/* Location of the msi capability */
 		__u16	entry_nr;	/* specific enabled entry */
 		unsigned default_irq;	/* default pre-assigned irq */
 	} msi_attrib;
@@ -47,8 +46,6 @@ struct msi_desc {
 
 	/* Last set MSI message */
 	struct msi_msg msg;
-
-	struct kobject kobj;
 };
 
 /*
@@ -60,7 +57,6 @@ int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc);
 void arch_teardown_msi_irq(unsigned int irq);
 int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);
 void arch_teardown_msi_irqs(struct pci_dev *dev);
-int arch_msi_check_device(struct pci_dev* dev, int nvec, int type);
 void arch_restore_msi_irqs(struct pci_dev *dev);
 
 void default_teardown_msi_irqs(struct pci_dev *dev);
@@ -77,8 +73,6 @@ struct msi_chip {
 	int (*setup_irq)(struct msi_chip *chip, struct pci_dev *dev,
 			 struct msi_desc *desc);
 	void (*teardown_irq)(struct msi_chip *chip, unsigned int irq);
-	int (*check_device)(struct msi_chip *chip, struct pci_dev *dev,
-			    int nvec, int type);
 };
 
 #endif /* LINUX_MSI_H */