Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1135 insertions, 0 deletions

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
new file mode 100644
index 0000000000..6ac0afae0c
--- /dev/null
+++ b/drivers/pci/controller/vmd.c
@@ -0,0 +1,1135 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Volume Management Device driver
+ * Copyright (c) 2015, Intel Corporation.
+ */
+
+#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/pci-acpi.h>
+#include <linux/pci-ecam.h>
+#include <linux/srcu.h>
+#include <linux/rculist.h>
+#include <linux/rcupdate.h>
+
+#include <asm/irqdomain.h>
+
+#define VMD_CFGBAR	0
+#define VMD_MEMBAR1	2
+#define VMD_MEMBAR2	4
+
+#define PCI_REG_VMCAP		0x40
+#define BUS_RESTRICT_CAP(vmcap)	(vmcap & 0x1)
+#define PCI_REG_VMCONFIG	0x44
+#define BUS_RESTRICT_CFG(vmcfg)	((vmcfg >> 8) & 0x3)
+#define VMCONFIG_MSI_REMAP	0x2
+#define PCI_REG_VMLOCK		0x70
+#define MB2_SHADOW_EN(vmlock)	(vmlock & 0x2)
+
+#define MB2_SHADOW_OFFSET	0x2000
+#define MB2_SHADOW_SIZE		16
+
+enum vmd_features {
+	/*
+	 * Device may contain registers which hint the physical location of the
+	 * membars, in order to allow proper address translation during
+	 * resource assignment to enable guest virtualization
+	 */
+	VMD_FEAT_HAS_MEMBAR_SHADOW		= (1 << 0),
+
+	/*
+	 * Device may provide root port configuration information which limits
+	 * bus numbering
+	 */
+	VMD_FEAT_HAS_BUS_RESTRICTIONS		= (1 << 1),
+
+	/*
+	 * Device contains physical location shadow registers in
+	 * vendor-specific capability space
+	 */
+	VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP	= (1 << 2),
+
+	/*
+	 * Device may use MSI-X vector 0 for software triggering and will not
+	 * be used for MSI remapping
+	 */
+	VMD_FEAT_OFFSET_FIRST_VECTOR		= (1 << 3),
+
+	/*
+	 * Device can bypass remapping MSI-X transactions into its MSI-X table,
+	 * avoiding the requirement of a VMD MSI domain for child device
+	 * interrupt handling.
+	 */
+	VMD_FEAT_CAN_BYPASS_MSI_REMAP		= (1 << 4),
+
+	/*
+	 * Enable ASPM on the PCIE root ports and set the default LTR of the
+	 * storage devices on platforms where these values are not configured by
+	 * BIOS. This is needed for laptops, which require these settings for
+	 * proper power management of the SoC.
+	 */
+	VMD_FEAT_BIOS_PM_QUIRK		= (1 << 5),
+};
+
+#define VMD_BIOS_PM_QUIRK_LTR	0x1003	/* 3145728 ns */
+
+#define VMD_FEATS_CLIENT	(VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |	\
+				 VMD_FEAT_HAS_BUS_RESTRICTIONS |	\
+				 VMD_FEAT_OFFSET_FIRST_VECTOR |		\
+				 VMD_FEAT_BIOS_PM_QUIRK)
+
+static DEFINE_IDA(vmd_instance_ida);
+
+/*
+ * 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.
+ * @irq:	back pointer to parent.
+ * @enabled:	true if driver enabled IRQ
+ * @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 vmd_irq_list	*irq;
+	bool			enabled;
+	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.
+ * @srcu:	SRCU struct for local synchronization.
+ * @count:	number of child IRQs assigned to this vector; used to track
+ *		sharing.
+ * @virq:	The underlying VMD Linux interrupt number
+ */
+struct vmd_irq_list {
+	struct list_head	irq_list;
+	struct srcu_struct	srcu;
+	unsigned int		count;
+	unsigned int		virq;
+};
+
+struct vmd_dev {
+	struct pci_dev		*dev;
+
+	spinlock_t		cfg_lock;
+	void __iomem		*cfgbar;
+
+	int msix_count;
+	struct vmd_irq_list	*irqs;
+
+	struct pci_sysdata	sysdata;
+	struct resource		resources[3];
+	struct irq_domain	*irq_domain;
+	struct pci_bus		*bus;
+	u8			busn_start;
+	u8			first_vec;
+	char			*name;
+	int			instance;
+};
+
+static inline struct vmd_dev *vmd_from_bus(struct pci_bus *bus)
+{
+	return container_of(bus->sysdata, struct vmd_dev, sysdata);
+}
+
+static inline unsigned int index_from_irqs(struct vmd_dev *vmd,
+					   struct vmd_irq_list *irqs)
+{
+	return irqs - vmd->irqs;
+}
+
+/*
+ * 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;
+	struct vmd_dev *vmd = irq_data_get_irq_handler_data(data);
+
+	memset(msg, 0, sizeof(*msg));
+	msg->address_hi = X86_MSI_BASE_ADDRESS_HIGH;
+	msg->arch_addr_lo.base_address = X86_MSI_BASE_ADDRESS_LOW;
+	msg->arch_addr_lo.destid_0_7 = index_from_irqs(vmd, irq);
+}
+
+/*
+ * 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;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&list_lock, flags);
+	WARN_ON(vmdirq->enabled);
+	list_add_tail_rcu(&vmdirq->node, &vmdirq->irq->irq_list);
+	vmdirq->enabled = true;
+	raw_spin_unlock_irqrestore(&list_lock, flags);
+
+	data->chip->irq_unmask(data);
+}
+
+static void vmd_irq_disable(struct irq_data *data)
+{
+	struct vmd_irq *vmdirq = data->chip_data;
+	unsigned long flags;
+
+	data->chip->irq_mask(data);
+
+	raw_spin_lock_irqsave(&list_lock, flags);
+	if (vmdirq->enabled) {
+		list_del_rcu(&vmdirq->node);
+		vmdirq->enabled = false;
+	}
+	raw_spin_unlock_irqrestore(&list_lock, flags);
+}
+
+/*
+ * 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, struct msi_desc *desc)
+{
+	unsigned long flags;
+	int i, best;
+
+	if (vmd->msix_count == 1 + vmd->first_vec)
+		return &vmd->irqs[vmd->first_vec];
+
+	/*
+	 * White list for fast-interrupt handlers. All others will share the
+	 * "slow" interrupt vector.
+	 */
+	switch (msi_desc_to_pci_dev(desc)->class) {
+	case PCI_CLASS_STORAGE_EXPRESS:
+		break;
+	default:
+		return &vmd->irqs[vmd->first_vec];
+	}
+
+	raw_spin_lock_irqsave(&list_lock, flags);
+	best = vmd->first_vec + 1;
+	for (i = best; i < vmd->msix_count; i++)
+		if (vmd->irqs[i].count < vmd->irqs[best].count)
+			best = i;
+	vmd->irqs[best].count++;
+	raw_spin_unlock_irqrestore(&list_lock, flags);
+
+	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 msi_desc *desc = arg->desc;
+	struct vmd_dev *vmd = vmd_from_bus(msi_desc_to_pci_dev(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, desc);
+	vmdirq->virq = virq;
+
+	irq_domain_set_info(domain, virq, vmdirq->irq->virq, info->chip, vmdirq,
+			    handle_untracked_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);
+	unsigned long flags;
+
+	synchronize_srcu(&vmdirq->irq->srcu);
+
+	/* XXX: Potential optimization to rebalance */
+	raw_spin_lock_irqsave(&list_lock, flags);
+	vmdirq->irq->count--;
+	raw_spin_unlock_irqrestore(&list_lock, flags);
+
+	kfree(vmdirq);
+}
+
+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,
+};
+
+static void vmd_set_msi_remapping(struct vmd_dev *vmd, bool enable)
+{
+	u16 reg;
+
+	pci_read_config_word(vmd->dev, PCI_REG_VMCONFIG, &reg);
+	reg = enable ? (reg & ~VMCONFIG_MSI_REMAP) :
+		       (reg | VMCONFIG_MSI_REMAP);
+	pci_write_config_word(vmd->dev, PCI_REG_VMCONFIG, reg);
+}
+
+static int vmd_create_irq_domain(struct vmd_dev *vmd)
+{
+	struct fwnode_handle *fn;
+
+	fn = irq_domain_alloc_named_id_fwnode("VMD-MSI", vmd->sysdata.domain);
+	if (!fn)
+		return -ENODEV;
+
+	vmd->irq_domain = pci_msi_create_irq_domain(fn, &vmd_msi_domain_info, NULL);
+	if (!vmd->irq_domain) {
+		irq_domain_free_fwnode(fn);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static void vmd_remove_irq_domain(struct vmd_dev *vmd)
+{
+	/*
+	 * Some production BIOS won't enable remapping between soft reboots.
+	 * Ensure remapping is restored before unloading the driver.
+	 */
+	if (!vmd->msix_count)
+		vmd_set_msi_remapping(vmd, true);
+
+	if (vmd->irq_domain) {
+		struct fwnode_handle *fn = vmd->irq_domain->fwnode;
+
+		irq_domain_remove(vmd->irq_domain);
+		irq_domain_free_fwnode(fn);
+	}
+}
+
+static void __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct pci_bus *bus,
+				  unsigned int devfn, int reg, int len)
+{
+	unsigned int busnr_ecam = bus->number - vmd->busn_start;
+	u32 offset = PCIE_ECAM_OFFSET(busnr_ecam, devfn, reg);
+
+	if (offset + len >= resource_size(&vmd->dev->resource[VMD_CFGBAR]))
+		return NULL;
+
+	return vmd->cfgbar + offset;
+}
+
+/*
+ * 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);
+	void __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);
+	void __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,
+};
+
+#ifdef CONFIG_ACPI
+static struct acpi_device *vmd_acpi_find_companion(struct pci_dev *pci_dev)
+{
+	struct pci_host_bridge *bridge;
+	u32 busnr, addr;
+
+	if (pci_dev->bus->ops != &vmd_ops)
+		return NULL;
+
+	bridge = pci_find_host_bridge(pci_dev->bus);
+	busnr = pci_dev->bus->number - bridge->bus->number;
+	/*
+	 * The address computation below is only applicable to relative bus
+	 * numbers below 32.
+	 */
+	if (busnr > 31)
+		return NULL;
+
+	addr = (busnr << 24) | ((u32)pci_dev->devfn << 16) | 0x8000FFFFU;
+
+	dev_dbg(&pci_dev->dev, "Looking for ACPI companion (address 0x%x)\n",
+		addr);
+
+	return acpi_find_child_device(ACPI_COMPANION(bridge->dev.parent), addr,
+				      false);
+}
+
+static bool hook_installed;
+
+static void vmd_acpi_begin(void)
+{
+	if (pci_acpi_set_companion_lookup_hook(vmd_acpi_find_companion))
+		return;
+
+	hook_installed = true;
+}
+
+static void vmd_acpi_end(void)
+{
+	if (!hook_installed)
+		return;
+
+	pci_acpi_clear_companion_lookup_hook();
+	hook_installed = false;
+}
+#else
+static inline void vmd_acpi_begin(void) { }
+static inline void vmd_acpi_end(void) { }
+#endif /* CONFIG_ACPI */
+
+static void vmd_domain_reset(struct vmd_dev *vmd)
+{
+	u16 bus, max_buses = resource_size(&vmd->resources[0]);
+	u8 dev, functions, fn, hdr_type;
+	char __iomem *base;
+
+	for (bus = 0; bus < max_buses; bus++) {
+		for (dev = 0; dev < 32; dev++) {
+			base = vmd->cfgbar + PCIE_ECAM_OFFSET(bus,
+						PCI_DEVFN(dev, 0), 0);
+
+			hdr_type = readb(base + PCI_HEADER_TYPE);
+
+			functions = (hdr_type & 0x80) ? 8 : 1;
+			for (fn = 0; fn < functions; fn++) {
+				base = vmd->cfgbar + PCIE_ECAM_OFFSET(bus,
+						PCI_DEVFN(dev, fn), 0);
+
+				hdr_type = readb(base + PCI_HEADER_TYPE) &
+						PCI_HEADER_TYPE_MASK;
+
+				if (hdr_type != PCI_HEADER_TYPE_BRIDGE ||
+				    (readw(base + PCI_CLASS_DEVICE) !=
+				     PCI_CLASS_BRIDGE_PCI))
+					continue;
+
+				/*
+				 * Temporarily disable the I/O range before updating
+				 * PCI_IO_BASE.
+				 */
+				writel(0x0000ffff, base + PCI_IO_BASE_UPPER16);
+				/* Update lower 16 bits of I/O base/limit */
+				writew(0x00f0, base + PCI_IO_BASE);
+				/* Update upper 16 bits of I/O base/limit */
+				writel(0, base + PCI_IO_BASE_UPPER16);
+
+				/* MMIO Base/Limit */
+				writel(0x0000fff0, base + PCI_MEMORY_BASE);
+
+				/* Prefetchable MMIO Base/Limit */
+				writel(0, base + PCI_PREF_LIMIT_UPPER32);
+				writel(0x0000fff0, base + PCI_PREF_MEMORY_BASE);
+				writel(0xffffffff, base + PCI_PREF_BASE_UPPER32);
+			}
+		}
+	}
+}
+
+static void vmd_attach_resources(struct vmd_dev *vmd)
+{
+	vmd->dev->resource[VMD_MEMBAR1].child = &vmd->resources[1];
+	vmd->dev->resource[VMD_MEMBAR2].child = &vmd->resources[2];
+}
+
+static void vmd_detach_resources(struct vmd_dev *vmd)
+{
+	vmd->dev->resource[VMD_MEMBAR1].child = NULL;
+	vmd->dev->resource[VMD_MEMBAR2].child = NULL;
+}
+
+/*
+ * VMD domains start at 0x10000 to not clash with ACPI _SEG domains.
+ * Per ACPI r6.0, sec 6.5.6,  _SEG returns an integer, of which the lower
+ * 16 bits are the PCI Segment Group (domain) number.  Other bits are
+ * currently reserved.
+ */
+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_get_phys_offsets(struct vmd_dev *vmd, bool native_hint,
+				resource_size_t *offset1,
+				resource_size_t *offset2)
+{
+	struct pci_dev *dev = vmd->dev;
+	u64 phys1, phys2;
+
+	if (native_hint) {
+		u32 vmlock;
+		int ret;
+
+		ret = pci_read_config_dword(dev, PCI_REG_VMLOCK, &vmlock);
+		if (ret || PCI_POSSIBLE_ERROR(vmlock))
+			return -ENODEV;
+
+		if (MB2_SHADOW_EN(vmlock)) {
+			void __iomem *membar2;
+
+			membar2 = pci_iomap(dev, VMD_MEMBAR2, 0);
+			if (!membar2)
+				return -ENOMEM;
+			phys1 = readq(membar2 + MB2_SHADOW_OFFSET);
+			phys2 = readq(membar2 + MB2_SHADOW_OFFSET + 8);
+			pci_iounmap(dev, membar2);
+		} else
+			return 0;
+	} else {
+		/* Hypervisor-Emulated Vendor-Specific Capability */
+		int pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
+		u32 reg, regu;
+
+		pci_read_config_dword(dev, pos + 4, &reg);
+
+		/* "SHDW" */
+		if (pos && reg == 0x53484457) {
+			pci_read_config_dword(dev, pos + 8, &reg);
+			pci_read_config_dword(dev, pos + 12, &regu);
+			phys1 = (u64) regu << 32 | reg;
+
+			pci_read_config_dword(dev, pos + 16, &reg);
+			pci_read_config_dword(dev, pos + 20, &regu);
+			phys2 = (u64) regu << 32 | reg;
+		} else
+			return 0;
+	}
+
+	*offset1 = dev->resource[VMD_MEMBAR1].start -
+			(phys1 & PCI_BASE_ADDRESS_MEM_MASK);
+	*offset2 = dev->resource[VMD_MEMBAR2].start -
+			(phys2 & PCI_BASE_ADDRESS_MEM_MASK);
+
+	return 0;
+}
+
+static int vmd_get_bus_number_start(struct vmd_dev *vmd)
+{
+	struct pci_dev *dev = vmd->dev;
+	u16 reg;
+
+	pci_read_config_word(dev, PCI_REG_VMCAP, &reg);
+	if (BUS_RESTRICT_CAP(reg)) {
+		pci_read_config_word(dev, PCI_REG_VMCONFIG, &reg);
+
+		switch (BUS_RESTRICT_CFG(reg)) {
+		case 0:
+			vmd->busn_start = 0;
+			break;
+		case 1:
+			vmd->busn_start = 128;
+			break;
+		case 2:
+			vmd->busn_start = 224;
+			break;
+		default:
+			pci_err(dev, "Unknown Bus Offset Setting (%d)\n",
+				BUS_RESTRICT_CFG(reg));
+			return -ENODEV;
+		}
+	}
+
+	return 0;
+}
+
+static irqreturn_t vmd_irq(int irq, void *data)
+{
+	struct vmd_irq_list *irqs = data;
+	struct vmd_irq *vmdirq;
+	int idx;
+
+	idx = srcu_read_lock(&irqs->srcu);
+	list_for_each_entry_rcu(vmdirq, &irqs->irq_list, node)
+		generic_handle_irq(vmdirq->virq);
+	srcu_read_unlock(&irqs->srcu, idx);
+
+	return IRQ_HANDLED;
+}
+
+static int vmd_alloc_irqs(struct vmd_dev *vmd)
+{
+	struct pci_dev *dev = vmd->dev;
+	int i, err;
+
+	vmd->msix_count = pci_msix_vec_count(dev);
+	if (vmd->msix_count < 0)
+		return -ENODEV;
+
+	vmd->msix_count = pci_alloc_irq_vectors(dev, vmd->first_vec + 1,
+						vmd->msix_count, PCI_IRQ_MSIX);
+	if (vmd->msix_count < 0)
+		return vmd->msix_count;
+
+	vmd->irqs = devm_kcalloc(&dev->dev, vmd->msix_count, sizeof(*vmd->irqs),
+				 GFP_KERNEL);
+	if (!vmd->irqs)
+		return -ENOMEM;
+
+	for (i = 0; i < vmd->msix_count; i++) {
+		err = init_srcu_struct(&vmd->irqs[i].srcu);
+		if (err)
+			return err;
+
+		INIT_LIST_HEAD(&vmd->irqs[i].irq_list);
+		vmd->irqs[i].virq = pci_irq_vector(dev, i);
+		err = devm_request_irq(&dev->dev, vmd->irqs[i].virq,
+				       vmd_irq, IRQF_NO_THREAD,
+				       vmd->name, &vmd->irqs[i]);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+/*
+ * Since VMD is an aperture to regular PCIe root ports, only allow it to
+ * control features that the OS is allowed to control on the physical PCI bus.
+ */
+static void vmd_copy_host_bridge_flags(struct pci_host_bridge *root_bridge,
+				       struct pci_host_bridge *vmd_bridge)
+{
+	vmd_bridge->native_pcie_hotplug = root_bridge->native_pcie_hotplug;
+	vmd_bridge->native_shpc_hotplug = root_bridge->native_shpc_hotplug;
+	vmd_bridge->native_aer = root_bridge->native_aer;
+	vmd_bridge->native_pme = root_bridge->native_pme;
+	vmd_bridge->native_ltr = root_bridge->native_ltr;
+	vmd_bridge->native_dpc = root_bridge->native_dpc;
+}
+
+/*
+ * Enable ASPM and LTR settings on devices that aren't configured by BIOS.
+ */
+static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata)
+{
+	unsigned long features = *(unsigned long *)userdata;
+	u16 ltr = VMD_BIOS_PM_QUIRK_LTR;
+	u32 ltr_reg;
+	int pos;
+
+	if (!(features & VMD_FEAT_BIOS_PM_QUIRK))
+		return 0;
+
+	pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL);
+
+	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR);
+	if (!pos)
+		return 0;
+
+	/*
+	 * Skip if the max snoop LTR is non-zero, indicating BIOS has set it
+	 * so the LTR quirk is not needed.
+	 */
+	pci_read_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, &ltr_reg);
+	if (!!(ltr_reg & (PCI_LTR_VALUE_MASK | PCI_LTR_SCALE_MASK)))
+		return 0;
+
+	/*
+	 * Set the default values to the maximum required by the platform to
+	 * allow the deepest power management savings. Write as a DWORD where
+	 * the lower word is the max snoop latency and the upper word is the
+	 * max non-snoop latency.
+	 */
+	ltr_reg = (ltr << 16) | ltr;
+	pci_write_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, ltr_reg);
+	pci_info(pdev, "VMD: Default LTR value set by driver\n");
+
+	return 0;
+}
+
+static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
+{
+	struct pci_sysdata *sd = &vmd->sysdata;
+	struct resource *res;
+	u32 upper_bits;
+	unsigned long flags;
+	LIST_HEAD(resources);
+	resource_size_t offset[2] = {0};
+	resource_size_t membar2_offset = 0x2000;
+	struct pci_bus *child;
+	struct pci_dev *dev;
+	int ret;
+
+	/*
+	 * Shadow registers may exist in certain VMD device ids which allow
+	 * guests to correctly assign host physical addresses to the root ports
+	 * and child devices. These registers will either return the host value
+	 * or 0, depending on an enable bit in the VMD device.
+	 */
+	if (features & VMD_FEAT_HAS_MEMBAR_SHADOW) {
+		membar2_offset = MB2_SHADOW_OFFSET + MB2_SHADOW_SIZE;
+		ret = vmd_get_phys_offsets(vmd, true, &offset[0], &offset[1]);
+		if (ret)
+			return ret;
+	} else if (features & VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP) {
+		ret = vmd_get_phys_offsets(vmd, false, &offset[0], &offset[1]);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * Certain VMD devices may have a root port configuration option which
+	 * limits the bus range to between 0-127, 128-255, or 224-255
+	 */
+	if (features & VMD_FEAT_HAS_BUS_RESTRICTIONS) {
+		ret = vmd_get_bus_number_start(vmd);
+		if (ret)
+			return ret;
+	}
+
+	res = &vmd->dev->resource[VMD_CFGBAR];
+	vmd->resources[0] = (struct resource) {
+		.name  = "VMD CFGBAR",
+		.start = vmd->busn_start,
+		.end   = vmd->busn_start + (resource_size(res) >> 20) - 1,
+		.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED,
+	};
+
+	/*
+	 * If the window is below 4GB, clear IORESOURCE_MEM_64 so we can
+	 * put 32-bit resources in the window.
+	 *
+	 * There's no hardware reason why a 64-bit window *couldn't*
+	 * contain a 32-bit resource, but pbus_size_mem() computes the
+	 * bridge window size assuming a 64-bit window will contain no
+	 * 32-bit resources.  __pci_assign_resource() enforces that
+	 * artificial restriction to make sure everything will fit.
+	 *
+	 * The only way we could use a 64-bit non-prefetchable MEMBAR is
+	 * if its address is <4GB so that we can convert it to a 32-bit
+	 * resource.  To be visible to the host OS, all VMD endpoints must
+	 * be initially configured by platform BIOS, which includes setting
+	 * up these resources.  We can assume the device is configured
+	 * according to the platform needs.
+	 */
+	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,
+		.parent = res,
+	};
+
+	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 + membar2_offset,
+		.end   = res->end,
+		.flags = flags,
+		.parent = res,
+	};
+
+	sd->vmd_dev = vmd->dev;
+	sd->domain = vmd_find_free_domain();
+	if (sd->domain < 0)
+		return sd->domain;
+
+	sd->node = pcibus_to_node(vmd->dev->bus);
+
+	/*
+	 * Currently MSI remapping must be enabled in guest passthrough mode
+	 * due to some missing interrupt remapping plumbing. This is probably
+	 * acceptable because the guest is usually CPU-limited and MSI
+	 * remapping doesn't become a performance bottleneck.
+	 */
+	if (!(features & VMD_FEAT_CAN_BYPASS_MSI_REMAP) ||
+	    offset[0] || offset[1]) {
+		ret = vmd_alloc_irqs(vmd);
+		if (ret)
+			return ret;
+
+		vmd_set_msi_remapping(vmd, true);
+
+		ret = vmd_create_irq_domain(vmd);
+		if (ret)
+			return ret;
+
+		/*
+		 * Override the IRQ domain bus token so the domain can be
+		 * distinguished from a regular PCI/MSI domain.
+		 */
+		irq_domain_update_bus_token(vmd->irq_domain, DOMAIN_BUS_VMD_MSI);
+	} else {
+		vmd_set_msi_remapping(vmd, false);
+	}
+
+	pci_add_resource(&resources, &vmd->resources[0]);
+	pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);
+	pci_add_resource_offset(&resources, &vmd->resources[2], offset[1]);
+
+	vmd->bus = pci_create_root_bus(&vmd->dev->dev, vmd->busn_start,
+				       &vmd_ops, sd, &resources);
+	if (!vmd->bus) {
+		pci_free_resource_list(&resources);
+		vmd_remove_irq_domain(vmd);
+		return -ENODEV;
+	}
+
+	vmd_copy_host_bridge_flags(pci_find_host_bridge(vmd->dev->bus),
+				   to_pci_host_bridge(vmd->bus->bridge));
+
+	vmd_attach_resources(vmd);
+	if (vmd->irq_domain)
+		dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain);
+	else
+		dev_set_msi_domain(&vmd->bus->dev,
+				   dev_get_msi_domain(&vmd->dev->dev));
+
+	vmd_acpi_begin();
+
+	pci_scan_child_bus(vmd->bus);
+	vmd_domain_reset(vmd);
+
+	/* When Intel VMD is enabled, the OS does not discover the Root Ports
+	 * owned by Intel VMD within the MMCFG space. pci_reset_bus() applies
+	 * a reset to the parent of the PCI device supplied as argument. This
+	 * is why we pass a child device, so the reset can be triggered at
+	 * the Intel bridge level and propagated to all the children in the
+	 * hierarchy.
+	 */
+	list_for_each_entry(child, &vmd->bus->children, node) {
+		if (!list_empty(&child->devices)) {
+			dev = list_first_entry(&child->devices,
+					       struct pci_dev, bus_list);
+			ret = pci_reset_bus(dev);
+			if (ret)
+				pci_warn(dev, "can't reset device: %d\n", ret);
+
+			break;
+		}
+	}
+
+	pci_assign_unassigned_bus_resources(vmd->bus);
+
+	pci_walk_bus(vmd->bus, vmd_pm_enable_quirk, &features);
+
+	/*
+	 * VMD root buses are virtual and don't return true on pci_is_pcie()
+	 * and will fail pcie_bus_configure_settings() early. It can instead be
+	 * run on each of the real root ports.
+	 */
+	list_for_each_entry(child, &vmd->bus->children, node)
+		pcie_bus_configure_settings(child);
+
+	pci_bus_add_devices(vmd->bus);
+
+	vmd_acpi_end();
+
+	WARN(sysfs_create_link(&vmd->dev->dev.kobj, &vmd->bus->dev.kobj,
+			       "domain"), "Can't create symlink to domain\n");
+	return 0;
+}
+
+static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+	unsigned long features = (unsigned long) id->driver_data;
+	struct vmd_dev *vmd;
+	int 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;
+	vmd->instance = ida_simple_get(&vmd_instance_ida, 0, 0, GFP_KERNEL);
+	if (vmd->instance < 0)
+		return vmd->instance;
+
+	vmd->name = devm_kasprintf(&dev->dev, GFP_KERNEL, "vmd%d",
+				   vmd->instance);
+	if (!vmd->name) {
+		err = -ENOMEM;
+		goto out_release_instance;
+	}
+
+	err = pcim_enable_device(dev);
+	if (err < 0)
+		goto out_release_instance;
+
+	vmd->cfgbar = pcim_iomap(dev, VMD_CFGBAR, 0);
+	if (!vmd->cfgbar) {
+		err = -ENOMEM;
+		goto out_release_instance;
+	}
+
+	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))) {
+		err = -ENODEV;
+		goto out_release_instance;
+	}
+
+	if (features & VMD_FEAT_OFFSET_FIRST_VECTOR)
+		vmd->first_vec = 1;
+
+	spin_lock_init(&vmd->cfg_lock);
+	pci_set_drvdata(dev, vmd);
+	err = vmd_enable_domain(vmd, features);
+	if (err)
+		goto out_release_instance;
+
+	dev_info(&vmd->dev->dev, "Bound to PCI domain %04x\n",
+		 vmd->sysdata.domain);
+	return 0;
+
+ out_release_instance:
+	ida_simple_remove(&vmd_instance_ida, vmd->instance);
+	return err;
+}
+
+static void vmd_cleanup_srcu(struct vmd_dev *vmd)
+{
+	int i;
+
+	for (i = 0; i < vmd->msix_count; i++)
+		cleanup_srcu_struct(&vmd->irqs[i].srcu);
+}
+
+static void vmd_remove(struct pci_dev *dev)
+{
+	struct vmd_dev *vmd = pci_get_drvdata(dev);
+
+	sysfs_remove_link(&vmd->dev->dev.kobj, "domain");
+	pci_stop_root_bus(vmd->bus);
+	pci_remove_root_bus(vmd->bus);
+	vmd_cleanup_srcu(vmd);
+	vmd_detach_resources(vmd);
+	vmd_remove_irq_domain(vmd);
+	ida_simple_remove(&vmd_instance_ida, vmd->instance);
+}
+
+static void vmd_shutdown(struct pci_dev *dev)
+{
+        struct vmd_dev *vmd = pci_get_drvdata(dev);
+
+        vmd_remove_irq_domain(vmd);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int vmd_suspend(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct vmd_dev *vmd = pci_get_drvdata(pdev);
+	int i;
+
+	for (i = 0; i < vmd->msix_count; i++)
+		devm_free_irq(dev, vmd->irqs[i].virq, &vmd->irqs[i]);
+
+	return 0;
+}
+
+static int vmd_resume(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct vmd_dev *vmd = pci_get_drvdata(pdev);
+	int err, i;
+
+       if (vmd->irq_domain)
+               vmd_set_msi_remapping(vmd, true);
+       else
+               vmd_set_msi_remapping(vmd, false);
+
+	for (i = 0; i < vmd->msix_count; i++) {
+		err = devm_request_irq(dev, vmd->irqs[i].virq,
+				       vmd_irq, IRQF_NO_THREAD,
+				       vmd->name, &vmd->irqs[i]);
+		if (err)
+			return err;
+	}
+
+	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_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_201D),
+		.driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP,},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_28C0),
+		.driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW |
+				VMD_FEAT_HAS_BUS_RESTRICTIONS |
+				VMD_FEAT_CAN_BYPASS_MSI_REMAP,},
+	{PCI_VDEVICE(INTEL, 0x467f),
+		.driver_data = VMD_FEATS_CLIENT,},
+	{PCI_VDEVICE(INTEL, 0x4c3d),
+		.driver_data = VMD_FEATS_CLIENT,},
+	{PCI_VDEVICE(INTEL, 0xa77f),
+		.driver_data = VMD_FEATS_CLIENT,},
+	{PCI_VDEVICE(INTEL, 0x7d0b),
+		.driver_data = VMD_FEATS_CLIENT,},
+	{PCI_VDEVICE(INTEL, 0xad0b),
+		.driver_data = VMD_FEATS_CLIENT,},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_9A0B),
+		.driver_data = VMD_FEATS_CLIENT,},
+	{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,
+	.shutdown	= vmd_shutdown,
+	.driver		= {
+		.pm	= &vmd_dev_pm_ops,
+	},
+};
+module_pci_driver(vmd_drv);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION("0.6");