Merge branch 'pci/host-vmd' into next

* pci/host-vmd:
  x86/PCI: Add driver for Intel Volume Management Device (VMD)
  PCI/AER: Use 32 bit PCI domain numbers
  x86/PCI: Allow DMA ops specific to a PCI domain
  irqdomain: Export irq_domain_set_info() for module use
  genirq/MSI: Relax msi_domain_alloc() to support parentless MSI irqdomains

10 files changed, 811 insertions, 11 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 9ea78171b43c..94544db33000 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8216,6 +8216,12 @@ S:	Maintained
 F:      Documentation/devicetree/bindings/pci/host-generic-pci.txt
 F:      drivers/pci/host/pci-host-generic.c
 
+PCI DRIVER FOR INTEL VOLUME MANAGEMENT DEVICE (VMD)
+M:      Keith Busch <keith.busch@intel.com>
+L:      linux-pci@vger.kernel.org
+S:      Supported
+F:      arch/x86/pci/vmd.c
+
 PCIE DRIVER FOR ST SPEAR13XX
 M:      Pratyush Anand <pratyush.anand@gmail.com>
 L:      linux-pci@vger.kernel.org
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index db3622f22b61..3e6aca822295 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2665,6 +2665,19 @@ config PMC_ATOM
         def_bool y
         depends on PCI
 
+config VMD
+        depends on PCI_MSI
+        tristate "Volume Management Device Driver"
+        default N
+        ---help---
+          Adds support for the Intel Volume Management Device (VMD). VMD is a
+          secondary PCI host bridge that allows PCI Express root ports,
+          and devices attached to them, to be removed from the default
+          PCI domain and placed within the VMD domain. This provides
+          more bus resources than are otherwise possible with a
+          single domain. If you know your system provides one of these and
+          has devices attached to it, say Y; if you are not sure, say N.
+
 source "net/Kconfig"
 
 source "drivers/Kconfig"
diff --git a/arch/x86/include/asm/device.h b/arch/x86/include/asm/device.h
index 03dd72957d2f..684ed6c3aa67 100644
--- a/arch/x86/include/asm/device.h
+++ b/arch/x86/include/asm/device.h
@@ -10,6 +10,16 @@ struct dev_archdata {
 #endif
 };
 
+#if defined(CONFIG_X86_DEV_DMA_OPS) && defined(CONFIG_PCI_DOMAINS)
+struct dma_domain {
+        struct list_head node;
+        struct dma_map_ops *dma_ops;
+        int domain_nr;
+};
+void add_dma_domain(struct dma_domain *domain);
+void del_dma_domain(struct dma_domain *domain);
+#endif
+
 struct pdev_archdata {
 };
 
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index 1e3408e88604..1815b736269d 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -130,6 +130,11 @@ struct irq_alloc_info {
                         char            *uv_name;
                 };
 #endif
+#if IS_ENABLED(CONFIG_VMD)
+                struct {
+                        struct msi_desc *desc;
+                };
+#endif
         };
 };
 
diff --git a/arch/x86/pci/Makefile b/arch/x86/pci/Makefile
index 5c6fc3577a49..97062a635b77 100644
--- a/arch/x86/pci/Makefile
+++ b/arch/x86/pci/Makefile
@@ -23,6 +23,8 @@ obj-y				+= bus_numa.o
 obj-$(CONFIG_AMD_NB)            += amd_bus.o
 obj-$(CONFIG_PCI_CNB20LE_QUIRK) += broadcom_bus.o
 
+obj-$(CONFIG_VMD) += vmd.o
+
 ifeq ($(CONFIG_PCI_DEBUG),y)
 EXTRA_CFLAGS += -DDEBUG
 endif
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index eccd4d99e6a4..2879efc73a96 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -641,6 +641,43 @@ unsigned int pcibios_assign_all_busses(void)
         return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;
 }
 
+#if defined(CONFIG_X86_DEV_DMA_OPS) && defined(CONFIG_PCI_DOMAINS)
+static LIST_HEAD(dma_domain_list);
+static DEFINE_SPINLOCK(dma_domain_list_lock);
+
+void add_dma_domain(struct dma_domain *domain)
+{
+        spin_lock(&dma_domain_list_lock);
+        list_add(&domain->node, &dma_domain_list);
+        spin_unlock(&dma_domain_list_lock);
+}
+EXPORT_SYMBOL_GPL(add_dma_domain);
+
+void del_dma_domain(struct dma_domain *domain)
+{
+        spin_lock(&dma_domain_list_lock);
+        list_del(&domain->node);
+        spin_unlock(&dma_domain_list_lock);
+}
+EXPORT_SYMBOL_GPL(del_dma_domain);
+
+static void set_dma_domain_ops(struct pci_dev *pdev)
+{
+        struct dma_domain *domain;
+
+        spin_lock(&dma_domain_list_lock);
+        list_for_each_entry(domain, &dma_domain_list, node) {
+                if (pci_domain_nr(pdev->bus) == domain->domain_nr) {
+                        pdev->dev.archdata.dma_ops = domain->dma_ops;
+                        break;
+                }
+        }
+        spin_unlock(&dma_domain_list_lock);
+}
+#else
+static void set_dma_domain_ops(struct pci_dev *pdev) {}
+#endif
+
 int pcibios_add_device(struct pci_dev *dev)
 {
         struct setup_data *data;
@@ -670,6 +707,7 @@ int pcibios_add_device(struct pci_dev *dev)
                 pa_data = data->next;
                 iounmap(data);
         }
+        set_dma_domain_ops(dev);
         return 0;
 }
 
diff --git a/arch/x86/pci/vmd.c b/arch/x86/pci/vmd.c
new file mode 100644
index 000000000000..d57e48016f15
--- /dev/null
+++ b/arch/x86/pci/vmd.c
@@ -0,0 +1,723 @@
+/*
+ * Volume Management Device driver
+ * Copyright (c) 2015, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/pci.h>
+#include <linux/rculist.h>
+#include <linux/rcupdate.h>
+
+#include <asm/irqdomain.h>
+#include <asm/device.h>
+#include <asm/msi.h>
+#include <asm/msidef.h>
+
+#define VMD_CFGBAR      0
+#define VMD_MEMBAR1     2
+#define VMD_MEMBAR2     4
+
+/*
+ * Lock for manipulating VMD IRQ lists.
+ */
+static DEFINE_RAW_SPINLOCK(list_lock);
+
+/**
+ * struct vmd_irq - private data to map driver IRQ to the VMD shared vector
+ * @node:       list item for parent traversal.
+ * @rcu:        RCU callback item for freeing.
+ * @irq:        back pointer to parent.
+ * @virq:       the virtual IRQ value provided to the requesting driver.
+ *
+ * Every MSI/MSI-X IRQ requested for a device in a VMD domain will be mapped to
+ * a VMD IRQ using this structure.
+ */
+struct vmd_irq {
+        struct list_head        node;
+        struct rcu_head         rcu;
+        struct vmd_irq_list     *irq;
+        unsigned int            virq;
+};
+
+/**
+ * struct vmd_irq_list - list of driver requested IRQs mapping to a VMD vector
+ * @irq_list:   the list of irq's the VMD one demuxes to.
+ * @vmd_vector: the h/w IRQ assigned to the VMD.
+ * @index:      index into the VMD MSI-X table; used for message routing.
+ * @count:      number of child IRQs assigned to this vector; used to track
+ *              sharing.
+ */
+struct vmd_irq_list {
+        struct list_head        irq_list;
+        struct vmd_dev          *vmd;
+        unsigned int            vmd_vector;
+        unsigned int            index;
+        unsigned int            count;
+};
+
+struct vmd_dev {
+        struct pci_dev          *dev;
+
+        spinlock_t              cfg_lock;
+        char __iomem            *cfgbar;
+
+        int msix_count;
+        struct msix_entry       *msix_entries;
+        struct vmd_irq_list     *irqs;
+
+        struct pci_sysdata      sysdata;
+        struct resource         resources[3];
+        struct irq_domain       *irq_domain;
+        struct pci_bus          *bus;
+
+#ifdef CONFIG_X86_DEV_DMA_OPS
+        struct dma_map_ops      dma_ops;
+        struct dma_domain       dma_domain;
+#endif
+};
+
+static inline struct vmd_dev *vmd_from_bus(struct pci_bus *bus)
+{
+        return container_of(bus->sysdata, struct vmd_dev, sysdata);
+}
+
+/*
+ * Drivers managing a device in a VMD domain allocate their own IRQs as before,
+ * but the MSI entry for the hardware it's driving will be programmed with a
+ * destination ID for the VMD MSI-X table.  The VMD muxes interrupts in its
+ * domain into one of its own, and the VMD driver de-muxes these for the
+ * handlers sharing that VMD IRQ.  The vmd irq_domain provides the operations
+ * and irq_chip to set this up.
+ */
+static void vmd_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+        struct vmd_irq *vmdirq = data->chip_data;
+        struct vmd_irq_list *irq = vmdirq->irq;
+
+        msg->address_hi = MSI_ADDR_BASE_HI;
+        msg->address_lo = MSI_ADDR_BASE_LO | MSI_ADDR_DEST_ID(irq->index);
+        msg->data = 0;
+}
+
+/*
+ * We rely on MSI_FLAG_USE_DEF_CHIP_OPS to set the IRQ mask/unmask ops.
+ */
+static void vmd_irq_enable(struct irq_data *data)
+{
+        struct vmd_irq *vmdirq = data->chip_data;
+
+        raw_spin_lock(&list_lock);
+        list_add_tail_rcu(&vmdirq->node, &vmdirq->irq->irq_list);
+        raw_spin_unlock(&list_lock);
+
+        data->chip->irq_unmask(data);
+}
+
+static void vmd_irq_disable(struct irq_data *data)
+{
+        struct vmd_irq *vmdirq = data->chip_data;
+
+        data->chip->irq_mask(data);
+
+        raw_spin_lock(&list_lock);
+        list_del_rcu(&vmdirq->node);
+        raw_spin_unlock(&list_lock);
+}
+
+/*
+ * XXX: Stubbed until we develop acceptable way to not create conflicts with
+ * other devices sharing the same vector.
+ */
+static int vmd_irq_set_affinity(struct irq_data *data,
+                                const struct cpumask *dest, bool force)
+{
+        return -EINVAL;
+}
+
+static struct irq_chip vmd_msi_controller = {
+        .name                   = "VMD-MSI",
+        .irq_enable             = vmd_irq_enable,
+        .irq_disable            = vmd_irq_disable,
+        .irq_compose_msi_msg    = vmd_compose_msi_msg,
+        .irq_set_affinity       = vmd_irq_set_affinity,
+};
+
+static irq_hw_number_t vmd_get_hwirq(struct msi_domain_info *info,
+                                     msi_alloc_info_t *arg)
+{
+        return 0;
+}
+
+/*
+ * XXX: We can be even smarter selecting the best IRQ once we solve the
+ * affinity problem.
+ */
+static struct vmd_irq_list *vmd_next_irq(struct vmd_dev *vmd)
+{
+        int i, best = 0;
+
+        raw_spin_lock(&list_lock);
+        for (i = 1; i < vmd->msix_count; i++)
+                if (vmd->irqs[i].count < vmd->irqs[best].count)
+                        best = i;
+        vmd->irqs[best].count++;
+        raw_spin_unlock(&list_lock);
+
+        return &vmd->irqs[best];
+}
+
+static int vmd_msi_init(struct irq_domain *domain, struct msi_domain_info *info,
+                        unsigned int virq, irq_hw_number_t hwirq,
+                        msi_alloc_info_t *arg)
+{
+        struct vmd_dev *vmd = vmd_from_bus(msi_desc_to_pci_dev(arg->desc)->bus);
+        struct vmd_irq *vmdirq = kzalloc(sizeof(*vmdirq), GFP_KERNEL);
+
+        if (!vmdirq)
+                return -ENOMEM;
+
+        INIT_LIST_HEAD(&vmdirq->node);
+        vmdirq->irq = vmd_next_irq(vmd);
+        vmdirq->virq = virq;
+
+        irq_domain_set_info(domain, virq, vmdirq->irq->vmd_vector, info->chip,
+                            vmdirq, handle_simple_irq, vmd, NULL);
+        return 0;
+}
+
+static void vmd_msi_free(struct irq_domain *domain,
+                        struct msi_domain_info *info, unsigned int virq)
+{
+        struct vmd_irq *vmdirq = irq_get_chip_data(virq);
+
+        /* XXX: Potential optimization to rebalance */
+        raw_spin_lock(&list_lock);
+        vmdirq->irq->count--;
+        raw_spin_unlock(&list_lock);
+
+        kfree_rcu(vmdirq, rcu);
+}
+
+static int vmd_msi_prepare(struct irq_domain *domain, struct device *dev,
+                           int nvec, msi_alloc_info_t *arg)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct vmd_dev *vmd = vmd_from_bus(pdev->bus);
+
+        if (nvec > vmd->msix_count)
+                return vmd->msix_count;
+
+        memset(arg, 0, sizeof(*arg));
+        return 0;
+}
+
+static void vmd_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
+{
+        arg->desc = desc;
+}
+
+static struct msi_domain_ops vmd_msi_domain_ops = {
+        .get_hwirq      = vmd_get_hwirq,
+        .msi_init       = vmd_msi_init,
+        .msi_free       = vmd_msi_free,
+        .msi_prepare    = vmd_msi_prepare,
+        .set_desc       = vmd_set_desc,
+};
+
+static struct msi_domain_info vmd_msi_domain_info = {
+        .flags          = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+                          MSI_FLAG_PCI_MSIX,
+        .ops            = &vmd_msi_domain_ops,
+        .chip           = &vmd_msi_controller,
+};
+
+#ifdef CONFIG_X86_DEV_DMA_OPS
+/*
+ * VMD replaces the requester ID with its own.  DMA mappings for devices in a
+ * VMD domain need to be mapped for the VMD, not the device requiring
+ * the mapping.
+ */
+static struct device *to_vmd_dev(struct device *dev)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct vmd_dev *vmd = vmd_from_bus(pdev->bus);
+
+        return &vmd->dev->dev;
+}
+
+static struct dma_map_ops *vmd_dma_ops(struct device *dev)
+{
+        return to_vmd_dev(dev)->archdata.dma_ops;
+}
+
+static void *vmd_alloc(struct device *dev, size_t size, dma_addr_t *addr,
+                       gfp_t flag, struct dma_attrs *attrs)
+{
+        return vmd_dma_ops(dev)->alloc(to_vmd_dev(dev), size, addr, flag,
+                                       attrs);
+}
+
+static void vmd_free(struct device *dev, size_t size, void *vaddr,
+                     dma_addr_t addr, struct dma_attrs *attrs)
+{
+        return vmd_dma_ops(dev)->free(to_vmd_dev(dev), size, vaddr, addr,
+                                      attrs);
+}
+
+static int vmd_mmap(struct device *dev, struct vm_area_struct *vma,
+                    void *cpu_addr, dma_addr_t addr, size_t size,
+                    struct dma_attrs *attrs)
+{
+        return vmd_dma_ops(dev)->mmap(to_vmd_dev(dev), vma, cpu_addr, addr,
+                                      size, attrs);
+}
+
+static int vmd_get_sgtable(struct device *dev, struct sg_table *sgt,
+                           void *cpu_addr, dma_addr_t addr, size_t size,
+                           struct dma_attrs *attrs)
+{
+        return vmd_dma_ops(dev)->get_sgtable(to_vmd_dev(dev), sgt, cpu_addr,
+                                             addr, size, attrs);
+}
+
+static dma_addr_t vmd_map_page(struct device *dev, struct page *page,
+                               unsigned long offset, size_t size,
+                               enum dma_data_direction dir,
+                               struct dma_attrs *attrs)
+{
+        return vmd_dma_ops(dev)->map_page(to_vmd_dev(dev), page, offset, size,
+                                          dir, attrs);
+}
+
+static void vmd_unmap_page(struct device *dev, dma_addr_t addr, size_t size,
+                           enum dma_data_direction dir, struct dma_attrs *attrs)
+{
+        vmd_dma_ops(dev)->unmap_page(to_vmd_dev(dev), addr, size, dir, attrs);
+}
+
+static int vmd_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+                      enum dma_data_direction dir, struct dma_attrs *attrs)
+{
+        return vmd_dma_ops(dev)->map_sg(to_vmd_dev(dev), sg, nents, dir, attrs);
+}
+
+static void vmd_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
+                         enum dma_data_direction dir, struct dma_attrs *attrs)
+{
+        vmd_dma_ops(dev)->unmap_sg(to_vmd_dev(dev), sg, nents, dir, attrs);
+}
+
+static void vmd_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
+                                    size_t size, enum dma_data_direction dir)
+{
+        vmd_dma_ops(dev)->sync_single_for_cpu(to_vmd_dev(dev), addr, size, dir);
+}
+
+static void vmd_sync_single_for_device(struct device *dev, dma_addr_t addr,
+                                       size_t size, enum dma_data_direction dir)
+{
+        vmd_dma_ops(dev)->sync_single_for_device(to_vmd_dev(dev), addr, size,
+                                                 dir);
+}
+
+static void vmd_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
+                                int nents, enum dma_data_direction dir)
+{
+        vmd_dma_ops(dev)->sync_sg_for_cpu(to_vmd_dev(dev), sg, nents, dir);
+}
+
+static void vmd_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
+                                   int nents, enum dma_data_direction dir)
+{
+        vmd_dma_ops(dev)->sync_sg_for_device(to_vmd_dev(dev), sg, nents, dir);
+}
+
+static int vmd_mapping_error(struct device *dev, dma_addr_t addr)
+{
+        return vmd_dma_ops(dev)->mapping_error(to_vmd_dev(dev), addr);
+}
+
+static int vmd_dma_supported(struct device *dev, u64 mask)
+{
+        return vmd_dma_ops(dev)->dma_supported(to_vmd_dev(dev), mask);
+}
+
+#ifdef ARCH_HAS_DMA_GET_REQUIRED_MASK
+static u64 vmd_get_required_mask(struct device *dev)
+{
+        return vmd_dma_ops(dev)->get_required_mask(to_vmd_dev(dev));
+}
+#endif
+
+static void vmd_teardown_dma_ops(struct vmd_dev *vmd)
+{
+        struct dma_domain *domain = &vmd->dma_domain;
+
+        if (vmd->dev->dev.archdata.dma_ops)
+                del_dma_domain(domain);
+}
+
+#define ASSIGN_VMD_DMA_OPS(source, dest, fn)    \
+        do {                                    \
+                if (source->fn)                 \
+                        dest->fn = vmd_##fn;    \
+        } while (0)
+
+static void vmd_setup_dma_ops(struct vmd_dev *vmd)
+{
+        const struct dma_map_ops *source = vmd->dev->dev.archdata.dma_ops;
+        struct dma_map_ops *dest = &vmd->dma_ops;
+        struct dma_domain *domain = &vmd->dma_domain;
+
+        domain->domain_nr = vmd->sysdata.domain;
+        domain->dma_ops = dest;
+
+        if (!source)
+                return;
+        ASSIGN_VMD_DMA_OPS(source, dest, alloc);
+        ASSIGN_VMD_DMA_OPS(source, dest, free);
+        ASSIGN_VMD_DMA_OPS(source, dest, mmap);
+        ASSIGN_VMD_DMA_OPS(source, dest, get_sgtable);
+        ASSIGN_VMD_DMA_OPS(source, dest, map_page);
+        ASSIGN_VMD_DMA_OPS(source, dest, unmap_page);
+        ASSIGN_VMD_DMA_OPS(source, dest, map_sg);
+        ASSIGN_VMD_DMA_OPS(source, dest, unmap_sg);
+        ASSIGN_VMD_DMA_OPS(source, dest, sync_single_for_cpu);
+        ASSIGN_VMD_DMA_OPS(source, dest, sync_single_for_device);
+        ASSIGN_VMD_DMA_OPS(source, dest, sync_sg_for_cpu);
+        ASSIGN_VMD_DMA_OPS(source, dest, sync_sg_for_device);
+        ASSIGN_VMD_DMA_OPS(source, dest, mapping_error);
+        ASSIGN_VMD_DMA_OPS(source, dest, dma_supported);
+#ifdef ARCH_HAS_DMA_GET_REQUIRED_MASK
+        ASSIGN_VMD_DMA_OPS(source, dest, get_required_mask);
+#endif
+        add_dma_domain(domain);
+}
+#undef ASSIGN_VMD_DMA_OPS
+#else
+static void vmd_teardown_dma_ops(struct vmd_dev *vmd) {}
+static void vmd_setup_dma_ops(struct vmd_dev *vmd) {}
+#endif
+
+static char __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct pci_bus *bus,
+                                  unsigned int devfn, int reg, int len)
+{
+        char __iomem *addr = vmd->cfgbar +
+                             (bus->number << 20) + (devfn << 12) + reg;
+
+        if ((addr - vmd->cfgbar) + len >=
+            resource_size(&vmd->dev->resource[VMD_CFGBAR]))
+                return NULL;
+
+        return addr;
+}
+
+/*
+ * CPU may deadlock if config space is not serialized on some versions of this
+ * hardware, so all config space access is done under a spinlock.
+ */
+static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg,
+                        int len, u32 *value)
+{
+        struct vmd_dev *vmd = vmd_from_bus(bus);
+        char __iomem *addr = vmd_cfg_addr(vmd, bus, devfn, reg, len);
+        unsigned long flags;
+        int ret = 0;
+
+        if (!addr)
+                return -EFAULT;
+
+        spin_lock_irqsave(&vmd->cfg_lock, flags);
+        switch (len) {
+        case 1:
+                *value = readb(addr);
+                break;
+        case 2:
+                *value = readw(addr);
+                break;
+        case 4:
+                *value = readl(addr);
+                break;
+        default:
+                ret = -EINVAL;
+                break;
+        }
+        spin_unlock_irqrestore(&vmd->cfg_lock, flags);
+        return ret;
+}
+
+/*
+ * VMD h/w converts non-posted config writes to posted memory writes. The
+ * read-back in this function forces the completion so it returns only after
+ * the config space was written, as expected.
+ */
+static int vmd_pci_write(struct pci_bus *bus, unsigned int devfn, int reg,
+                         int len, u32 value)
+{
+        struct vmd_dev *vmd = vmd_from_bus(bus);
+        char __iomem *addr = vmd_cfg_addr(vmd, bus, devfn, reg, len);
+        unsigned long flags;
+        int ret = 0;
+
+        if (!addr)
+                return -EFAULT;
+
+        spin_lock_irqsave(&vmd->cfg_lock, flags);
+        switch (len) {
+        case 1:
+                writeb(value, addr);
+                readb(addr);
+                break;
+        case 2:
+                writew(value, addr);
+                readw(addr);
+                break;
+        case 4:
+                writel(value, addr);
+                readl(addr);
+                break;
+        default:
+                ret = -EINVAL;
+                break;
+        }
+        spin_unlock_irqrestore(&vmd->cfg_lock, flags);
+        return ret;
+}
+
+static struct pci_ops vmd_ops = {
+        .read           = vmd_pci_read,
+        .write          = vmd_pci_write,
+};
+
+/*
+ * VMD domains start at 0x1000 to not clash with ACPI _SEG domains.
+ */
+static int vmd_find_free_domain(void)
+{
+        int domain = 0xffff;
+        struct pci_bus *bus = NULL;
+
+        while ((bus = pci_find_next_bus(bus)) != NULL)
+                domain = max_t(int, domain, pci_domain_nr(bus));
+        return domain + 1;
+}
+
+static int vmd_enable_domain(struct vmd_dev *vmd)
+{
+        struct pci_sysdata *sd = &vmd->sysdata;
+        struct resource *res;
+        u32 upper_bits;
+        unsigned long flags;
+        LIST_HEAD(resources);
+
+        res = &vmd->dev->resource[VMD_CFGBAR];
+        vmd->resources[0] = (struct resource) {
+                .name  = "VMD CFGBAR",
+                .start = res->start,
+                .end   = (resource_size(res) >> 20) - 1,
+                .flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED,
+        };
+
+        res = &vmd->dev->resource[VMD_MEMBAR1];
+        upper_bits = upper_32_bits(res->end);
+        flags = res->flags & ~IORESOURCE_SIZEALIGN;
+        if (!upper_bits)
+                flags &= ~IORESOURCE_MEM_64;
+        vmd->resources[1] = (struct resource) {
+                .name  = "VMD MEMBAR1",
+                .start = res->start,
+                .end   = res->end,
+                .flags = flags,
+        };
+
+        res = &vmd->dev->resource[VMD_MEMBAR2];
+        upper_bits = upper_32_bits(res->end);
+        flags = res->flags & ~IORESOURCE_SIZEALIGN;
+        if (!upper_bits)
+                flags &= ~IORESOURCE_MEM_64;
+        vmd->resources[2] = (struct resource) {
+                .name  = "VMD MEMBAR2",
+                .start = res->start + 0x2000,
+                .end   = res->end,
+                .flags = flags,
+        };
+
+        sd->domain = vmd_find_free_domain();
+        if (sd->domain < 0)
+                return sd->domain;
+
+        sd->node = pcibus_to_node(vmd->dev->bus);
+
+        vmd->irq_domain = pci_msi_create_irq_domain(NULL, &vmd_msi_domain_info,
+                                                    NULL);
+        if (!vmd->irq_domain)
+                return -ENODEV;
+
+        pci_add_resource(&resources, &vmd->resources[0]);
+        pci_add_resource(&resources, &vmd->resources[1]);
+        pci_add_resource(&resources, &vmd->resources[2]);
+        vmd->bus = pci_create_root_bus(&vmd->dev->dev, 0, &vmd_ops, sd,
+                                       &resources);
+        if (!vmd->bus) {
+                pci_free_resource_list(&resources);
+                irq_domain_remove(vmd->irq_domain);
+                return -ENODEV;
+        }
+
+        vmd_setup_dma_ops(vmd);
+        dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain);
+        pci_rescan_bus(vmd->bus);
+
+        WARN(sysfs_create_link(&vmd->dev->dev.kobj, &vmd->bus->dev.kobj,
+                               "domain"), "Can't create symlink to domain\n");
+        return 0;
+}
+
+static irqreturn_t vmd_irq(int irq, void *data)
+{
+        struct vmd_irq_list *irqs = data;
+        struct vmd_irq *vmdirq;
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(vmdirq, &irqs->irq_list, node)
+                generic_handle_irq(vmdirq->virq);
+        rcu_read_unlock();
+
+        return IRQ_HANDLED;
+}
+
+static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+        struct vmd_dev *vmd;
+        int i, err;
+
+        if (resource_size(&dev->resource[VMD_CFGBAR]) < (1 << 20))
+                return -ENOMEM;
+
+        vmd = devm_kzalloc(&dev->dev, sizeof(*vmd), GFP_KERNEL);
+        if (!vmd)
+                return -ENOMEM;
+
+        vmd->dev = dev;
+        err = pcim_enable_device(dev);
+        if (err < 0)
+                return err;
+
+        vmd->cfgbar = pcim_iomap(dev, VMD_CFGBAR, 0);
+        if (!vmd->cfgbar)
+                return -ENOMEM;
+
+        pci_set_master(dev);
+        if (dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(64)) &&
+            dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32)))
+                return -ENODEV;
+
+        vmd->msix_count = pci_msix_vec_count(dev);
+        if (vmd->msix_count < 0)
+                return -ENODEV;
+
+        vmd->irqs = devm_kcalloc(&dev->dev, vmd->msix_count, sizeof(*vmd->irqs),
+                                 GFP_KERNEL);
+        if (!vmd->irqs)
+                return -ENOMEM;
+
+        vmd->msix_entries = devm_kcalloc(&dev->dev, vmd->msix_count,
+                                         sizeof(*vmd->msix_entries),
+                                         GFP_KERNEL);
+        if (!vmd->msix_entries)
+                return -ENOMEM;
+        for (i = 0; i < vmd->msix_count; i++)
+                vmd->msix_entries[i].entry = i;
+
+        vmd->msix_count = pci_enable_msix_range(vmd->dev, vmd->msix_entries, 1,
+                                                vmd->msix_count);
+        if (vmd->msix_count < 0)
+                return vmd->msix_count;
+
+        for (i = 0; i < vmd->msix_count; i++) {
+                INIT_LIST_HEAD(&vmd->irqs[i].irq_list);
+                vmd->irqs[i].vmd_vector = vmd->msix_entries[i].vector;
+                vmd->irqs[i].index = i;
+
+                err = devm_request_irq(&dev->dev, vmd->irqs[i].vmd_vector,
+                                       vmd_irq, 0, "vmd", &vmd->irqs[i]);
+                if (err)
+                        return err;
+        }
+
+        spin_lock_init(&vmd->cfg_lock);
+        pci_set_drvdata(dev, vmd);
+        err = vmd_enable_domain(vmd);
+        if (err)
+                return err;
+
+        dev_info(&vmd->dev->dev, "Bound to PCI domain %04x\n",
+                 vmd->sysdata.domain);
+        return 0;
+}
+
+static void vmd_remove(struct pci_dev *dev)
+{
+        struct vmd_dev *vmd = pci_get_drvdata(dev);
+
+        pci_set_drvdata(dev, NULL);
+        sysfs_remove_link(&vmd->dev->dev.kobj, "domain");
+        pci_stop_root_bus(vmd->bus);
+        pci_remove_root_bus(vmd->bus);
+        vmd_teardown_dma_ops(vmd);
+        irq_domain_remove(vmd->irq_domain);
+}
+
+#ifdef CONFIG_PM
+static int vmd_suspend(struct device *dev)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+
+        pci_save_state(pdev);
+        return 0;
+}
+
+static int vmd_resume(struct device *dev)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+
+        pci_restore_state(pdev);
+        return 0;
+}
+#endif
+static SIMPLE_DEV_PM_OPS(vmd_dev_pm_ops, vmd_suspend, vmd_resume);
+
+static const struct pci_device_id vmd_ids[] = {
+        {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x201d),},
+        {0,}
+};
+MODULE_DEVICE_TABLE(pci, vmd_ids);
+
+static struct pci_driver vmd_drv = {
+        .name           = "vmd",
+        .id_table       = vmd_ids,
+        .probe          = vmd_probe,
+        .remove         = vmd_remove,
+        .driver         = {
+                .pm     = &vmd_dev_pm_ops,
+        },
+};
+module_pci_driver(vmd_drv);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION("0.6");
diff --git a/drivers/pci/pcie/aer/aer_inject.c b/drivers/pci/pcie/aer/aer_inject.c
index 182224acedbe..20db790465dd 100644
--- a/drivers/pci/pcie/aer/aer_inject.c
+++ b/drivers/pci/pcie/aer/aer_inject.c
@@ -41,12 +41,12 @@ struct aer_error_inj {
         u32 header_log1;
         u32 header_log2;
         u32 header_log3;
-        u16 domain;
+        u32 domain;
 };
 
 struct aer_error {
         struct list_head list;
-        u16 domain;
+        u32 domain;
         unsigned int bus;
         unsigned int devfn;
         int pos_cap_err;
@@ -74,7 +74,7 @@ static LIST_HEAD(pci_bus_ops_list);
 /* Protect einjected and pci_bus_ops_list */
 static DEFINE_SPINLOCK(inject_lock);
 
-static void aer_error_init(struct aer_error *err, u16 domain,
+static void aer_error_init(struct aer_error *err, u32 domain,
                            unsigned int bus, unsigned int devfn,
                            int pos_cap_err)
 {
@@ -86,7 +86,7 @@ static void aer_error_init(struct aer_error *err, u16 domain,
 }
 
 /* inject_lock must be held before calling */
-static struct aer_error *__find_aer_error(u16 domain, unsigned int bus,
+static struct aer_error *__find_aer_error(u32 domain, unsigned int bus,
                                           unsigned int devfn)
 {
         struct aer_error *err;
@@ -106,7 +106,7 @@ static struct aer_error *__find_aer_error_by_dev(struct pci_dev *dev)
         int domain = pci_domain_nr(dev->bus);
         if (domain < 0)
                 return NULL;
-        return __find_aer_error((u16)domain, dev->bus->number, dev->devfn);
+        return __find_aer_error(domain, dev->bus->number, dev->devfn);
 }
 
 /* inject_lock must be held before calling */
@@ -196,7 +196,7 @@ static int pci_read_aer(struct pci_bus *bus, unsigned int devfn, int where,
         domain = pci_domain_nr(bus);
         if (domain < 0)
                 goto out;
-        err = __find_aer_error((u16)domain, bus->number, devfn);
+        err = __find_aer_error(domain, bus->number, devfn);
         if (!err)
                 goto out;
 
@@ -228,7 +228,7 @@ static int pci_write_aer(struct pci_bus *bus, unsigned int devfn, int where,
         domain = pci_domain_nr(bus);
         if (domain < 0)
                 goto out;
-        err = __find_aer_error((u16)domain, bus->number, devfn);
+        err = __find_aer_error(domain, bus->number, devfn);
         if (!err)
                 goto out;
 
@@ -329,7 +329,7 @@ static int aer_inject(struct aer_error_inj *einj)
         u32 sever, cor_mask, uncor_mask, cor_mask_orig = 0, uncor_mask_orig = 0;
         int ret = 0;
 
-        dev = pci_get_domain_bus_and_slot((int)einj->domain, einj->bus, devfn);
+        dev = pci_get_domain_bus_and_slot(einj->domain, einj->bus, devfn);
         if (!dev)
                 return -ENODEV;
         rpdev = pcie_find_root_port(dev);
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 22aa9612ef7c..ca05cc841f00 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -1058,6 +1058,7 @@ void irq_domain_set_info(struct irq_domain *domain, unsigned int virq,
         __irq_set_handler(virq, handler, 0, handler_name);
         irq_set_handler_data(virq, handler_data);
 }
+EXPORT_SYMBOL(irq_domain_set_info);
 
 /**
  * irq_domain_reset_irq_data - Clear hwirq, chip and chip_data in @irq_data
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 6b0c0b74a2a1..5e15cb4b2f00 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -109,9 +109,11 @@ static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
         if (irq_find_mapping(domain, hwirq) > 0)
                 return -EEXIST;
 
-        ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
-        if (ret < 0)
-                return ret;
+        if (domain->parent) {
+                ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
+                if (ret < 0)
+                        return ret;
+        }
 
         for (i = 0; i < nr_irqs; i++) {
                 ret = ops->msi_init(domain, info, virq + i, hwirq + i, arg);