1 files changed, 571 insertions, 0 deletions

diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
new file mode 100644
index 000000000000..f567965c0620
--- /dev/null
+++ b/arch/x86/pci/xen.c
@@ -0,0 +1,571 @@
+/*
+ * Xen PCI Frontend Stub - puts some "dummy" functions in to the Linux
+ *                         x86 PCI core to support the Xen PCI Frontend
+ *
+ *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/acpi.h>
+
+#include <linux/io.h>
+#include <asm/io_apic.h>
+#include <asm/pci_x86.h>
+
+#include <asm/xen/hypervisor.h>
+
+#include <xen/features.h>
+#include <xen/events.h>
+#include <asm/xen/pci.h>
+
+#ifdef CONFIG_ACPI
+static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
+                                 int trigger, int polarity)
+{
+        int rc, irq;
+        struct physdev_map_pirq map_irq;
+        int shareable = 0;
+        char *name;
+
+        if (!xen_hvm_domain())
+                return -1;
+
+        map_irq.domid = DOMID_SELF;
+        map_irq.type = MAP_PIRQ_TYPE_GSI;
+        map_irq.index = gsi;
+        map_irq.pirq = -1;
+
+        rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
+        if (rc) {
+                printk(KERN_WARNING "xen map irq failed %d\n", rc);
+                return -1;
+        }
+
+        if (trigger == ACPI_EDGE_SENSITIVE) {
+                shareable = 0;
+                name = "ioapic-edge";
+        } else {
+                shareable = 1;
+                name = "ioapic-level";
+        }
+
+        irq = xen_bind_pirq_gsi_to_irq(gsi, map_irq.pirq, shareable, name);
+
+        printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
+
+        return irq;
+}
+#endif
+
+#if defined(CONFIG_PCI_MSI)
+#include <linux/msi.h>
+#include <asm/msidef.h>
+
+struct xen_pci_frontend_ops *xen_pci_frontend;
+EXPORT_SYMBOL_GPL(xen_pci_frontend);
+
+#define XEN_PIRQ_MSI_DATA  (MSI_DATA_TRIGGER_EDGE | \
+                MSI_DATA_LEVEL_ASSERT | (3 << 8) | MSI_DATA_VECTOR(0))
+
+static void xen_msi_compose_msg(struct pci_dev *pdev, unsigned int pirq,
+                struct msi_msg *msg)
+{
+        /* We set vector == 0 to tell the hypervisor we don't care about it,
+         * but we want a pirq setup instead.
+         * We use the dest_id field to pass the pirq that we want. */
+        msg->address_hi = MSI_ADDR_BASE_HI | MSI_ADDR_EXT_DEST_ID(pirq);
+        msg->address_lo =
+                MSI_ADDR_BASE_LO |
+                MSI_ADDR_DEST_MODE_PHYSICAL |
+                MSI_ADDR_REDIRECTION_CPU |
+                MSI_ADDR_DEST_ID(pirq);
+
+        msg->data = XEN_PIRQ_MSI_DATA;
+}
+
+static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+        int irq, pirq;
+        struct msi_desc *msidesc;
+        struct msi_msg msg;
+
+        list_for_each_entry(msidesc, &dev->msi_list, list) {
+                __read_msi_msg(msidesc, &msg);
+                pirq = MSI_ADDR_EXT_DEST_ID(msg.address_hi) |
+                        ((msg.address_lo >> MSI_ADDR_DEST_ID_SHIFT) & 0xff);
+                if (msg.data != XEN_PIRQ_MSI_DATA ||
+                    xen_irq_from_pirq(pirq) < 0) {
+                        pirq = xen_allocate_pirq_msi(dev, msidesc);
+                        if (pirq < 0)
+                                goto error;
+                        xen_msi_compose_msg(dev, pirq, &msg);
+                        __write_msi_msg(msidesc, &msg);
+                        dev_dbg(&dev->dev, "xen: msi bound to pirq=%d\n", pirq);
+                } else {
+                        dev_dbg(&dev->dev,
+                                "xen: msi already bound to pirq=%d\n", pirq);
+                }
+                irq = xen_bind_pirq_msi_to_irq(dev, msidesc, pirq, 0,
+                                               (type == PCI_CAP_ID_MSIX) ?
+                                               "msi-x" : "msi",
+                                               DOMID_SELF);
+                if (irq < 0)
+                        goto error;
+                dev_dbg(&dev->dev,
+                        "xen: msi --> pirq=%d --> irq=%d\n", pirq, irq);
+        }
+        return 0;
+
+error:
+        dev_err(&dev->dev,
+                "Xen PCI frontend has not registered MSI/MSI-X support!\n");
+        return -ENODEV;
+}
+
+/*
+ * For MSI interrupts we have to use drivers/xen/event.s functions to
+ * allocate an irq_desc and setup the right */
+
+
+static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+        int irq, ret, i;
+        struct msi_desc *msidesc;
+        int *v;
+
+        v = kzalloc(sizeof(int) * max(1, nvec), GFP_KERNEL);
+        if (!v)
+                return -ENOMEM;
+
+        if (type == PCI_CAP_ID_MSIX)
+                ret = xen_pci_frontend_enable_msix(dev, v, nvec);
+        else
+                ret = xen_pci_frontend_enable_msi(dev, v);
+        if (ret)
+                goto error;
+        i = 0;
+        list_for_each_entry(msidesc, &dev->msi_list, list) {
+                irq = xen_bind_pirq_msi_to_irq(dev, msidesc, v[i], 0,
+                                               (type == PCI_CAP_ID_MSIX) ?
+                                               "pcifront-msi-x" :
+                                               "pcifront-msi",
+                                                DOMID_SELF);
+                if (irq < 0)
+                        goto free;
+                i++;
+        }
+        kfree(v);
+        return 0;
+
+error:
+        dev_err(&dev->dev, "Xen PCI frontend has not registered MSI/MSI-X support!\n");
+free:
+        kfree(v);
+        return ret;
+}
+
+static void xen_teardown_msi_irqs(struct pci_dev *dev)
+{
+        struct msi_desc *msidesc;
+
+        msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
+        if (msidesc->msi_attrib.is_msix)
+                xen_pci_frontend_disable_msix(dev);
+        else
+                xen_pci_frontend_disable_msi(dev);
+
+        /* Free the IRQ's and the msidesc using the generic code. */
+        default_teardown_msi_irqs(dev);
+}
+
+static void xen_teardown_msi_irq(unsigned int irq)
+{
+        xen_destroy_irq(irq);
+}
+
+#ifdef CONFIG_XEN_DOM0
+static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+        int ret = 0;
+        struct msi_desc *msidesc;
+
+        list_for_each_entry(msidesc, &dev->msi_list, list) {
+                struct physdev_map_pirq map_irq;
+                domid_t domid;
+
+                domid = ret = xen_find_device_domain_owner(dev);
+                /* N.B. Casting int's -ENODEV to uint16_t results in 0xFFED,
+                 * hence check ret value for < 0. */
+                if (ret < 0)
+                        domid = DOMID_SELF;
+
+                memset(&map_irq, 0, sizeof(map_irq));
+                map_irq.domid = domid;
+                map_irq.type = MAP_PIRQ_TYPE_MSI;
+                map_irq.index = -1;
+                map_irq.pirq = -1;
+                map_irq.bus = dev->bus->number;
+                map_irq.devfn = dev->devfn;
+
+                if (type == PCI_CAP_ID_MSIX) {
+                        int pos;
+                        u32 table_offset, bir;
+
+                        pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
+
+                        pci_read_config_dword(dev, pos + PCI_MSIX_TABLE,
+                                              &table_offset);
+                        bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
+
+                        map_irq.table_base = pci_resource_start(dev, bir);
+                        map_irq.entry_nr = msidesc->msi_attrib.entry_nr;
+                }
+
+                ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
+                if (ret) {
+                        dev_warn(&dev->dev, "xen map irq failed %d for %d domain\n",
+                                 ret, domid);
+                        goto out;
+                }
+
+                ret = xen_bind_pirq_msi_to_irq(dev, msidesc,
+                                               map_irq.pirq, map_irq.index,
+                                               (type == PCI_CAP_ID_MSIX) ?
+                                               "msi-x" : "msi",
+                                                domid);
+                if (ret < 0)
+                        goto out;
+        }
+        ret = 0;
+out:
+        return ret;
+}
+#endif
+#endif
+
+static int xen_pcifront_enable_irq(struct pci_dev *dev)
+{
+        int rc;
+        int share = 1;
+        int pirq;
+        u8 gsi;
+
+        rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
+        if (rc < 0) {
+                dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
+                         rc);
+                return rc;
+        }
+
+        rc = xen_allocate_pirq_gsi(gsi);
+        if (rc < 0) {
+                dev_warn(&dev->dev, "Xen PCI: failed to allocate a PIRQ for GSI%d: %d\n",
+                         gsi, rc);
+                return rc;
+        }
+        pirq = rc;
+
+        if (gsi < NR_IRQS_LEGACY)
+                share = 0;
+
+        rc = xen_bind_pirq_gsi_to_irq(gsi, pirq, share, "pcifront");
+        if (rc < 0) {
+                dev_warn(&dev->dev, "Xen PCI: failed to bind GSI%d (PIRQ%d) to IRQ: %d\n",
+                         gsi, pirq, rc);
+                return rc;
+        }
+
+        dev->irq = rc;
+        dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);
+        return 0;
+}
+
+int __init pci_xen_init(void)
+{
+        if (!xen_pv_domain() || xen_initial_domain())
+                return -ENODEV;
+
+        printk(KERN_INFO "PCI: setting up Xen PCI frontend stub\n");
+
+        pcibios_set_cache_line_size();
+
+        pcibios_enable_irq = xen_pcifront_enable_irq;
+        pcibios_disable_irq = NULL;
+
+#ifdef CONFIG_ACPI
+        /* Keep ACPI out of the picture */
+        acpi_noirq = 1;
+#endif
+
+#ifdef CONFIG_PCI_MSI
+        x86_msi.setup_msi_irqs = xen_setup_msi_irqs;
+        x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
+        x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs;
+#endif
+        return 0;
+}
+
+int __init pci_xen_hvm_init(void)
+{
+        if (!xen_feature(XENFEAT_hvm_pirqs))
+                return 0;
+
+#ifdef CONFIG_ACPI
+        /*
+         * We don't want to change the actual ACPI delivery model,
+         * just how GSIs get registered.
+         */
+        __acpi_register_gsi = acpi_register_gsi_xen_hvm;
+#endif
+
+#ifdef CONFIG_PCI_MSI
+        x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs;
+        x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
+#endif
+        return 0;
+}
+
+#ifdef CONFIG_XEN_DOM0
+static int xen_register_pirq(u32 gsi, int gsi_override, int triggering)
+{
+        int rc, pirq, irq = -1;
+        struct physdev_map_pirq map_irq;
+        int shareable = 0;
+        char *name;
+
+        if (!xen_pv_domain())
+                return -1;
+
+        if (triggering == ACPI_EDGE_SENSITIVE) {
+                shareable = 0;
+                name = "ioapic-edge";
+        } else {
+                shareable = 1;
+                name = "ioapic-level";
+        }
+        pirq = xen_allocate_pirq_gsi(gsi);
+        if (pirq < 0)
+                goto out;
+
+        if (gsi_override >= 0)
+                irq = xen_bind_pirq_gsi_to_irq(gsi_override, pirq, shareable, name);
+        else
+                irq = xen_bind_pirq_gsi_to_irq(gsi, pirq, shareable, name);
+        if (irq < 0)
+                goto out;
+
+        printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d (gsi=%d)\n", pirq, irq, gsi);
+
+        map_irq.domid = DOMID_SELF;
+        map_irq.type = MAP_PIRQ_TYPE_GSI;
+        map_irq.index = gsi;
+        map_irq.pirq = pirq;
+
+        rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
+        if (rc) {
+                printk(KERN_WARNING "xen map irq failed %d\n", rc);
+                return -1;
+        }
+
+out:
+        return irq;
+}
+
+static int xen_register_gsi(u32 gsi, int gsi_override, int triggering, int polarity)
+{
+        int rc, irq;
+        struct physdev_setup_gsi setup_gsi;
+
+        if (!xen_pv_domain())
+                return -1;
+
+        printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n",
+                        gsi, triggering, polarity);
+
+        irq = xen_register_pirq(gsi, gsi_override, triggering);
+
+        setup_gsi.gsi = gsi;
+        setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1);
+        setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
+
+        rc = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
+        if (rc == -EEXIST)
+                printk(KERN_INFO "Already setup the GSI :%d\n", gsi);
+        else if (rc) {
+                printk(KERN_ERR "Failed to setup GSI :%d, err_code:%d\n",
+                                gsi, rc);
+        }
+
+        return irq;
+}
+
+static __init void xen_setup_acpi_sci(void)
+{
+        int rc;
+        int trigger, polarity;
+        int gsi = acpi_sci_override_gsi;
+        int irq = -1;
+        int gsi_override = -1;
+
+        if (!gsi)
+                return;
+
+        rc = acpi_get_override_irq(gsi, &trigger, &polarity);
+        if (rc) {
+                printk(KERN_WARNING "xen: acpi_get_override_irq failed for acpi"
+                                " sci, rc=%d\n", rc);
+                return;
+        }
+        trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
+        polarity = polarity ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
+        
+        printk(KERN_INFO "xen: sci override: global_irq=%d trigger=%d "
+                        "polarity=%d\n", gsi, trigger, polarity);
+
+        /* Before we bind the GSI to a Linux IRQ, check whether
+         * we need to override it with bus_irq (IRQ) value. Usually for
+         * IRQs below IRQ_LEGACY_IRQ this holds IRQ == GSI, as so:
+         *  ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 low level)
+         * but there are oddballs where the IRQ != GSI:
+         *  ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 20 low level)
+         * which ends up being: gsi_to_irq[9] == 20
+         * (which is what acpi_gsi_to_irq ends up calling when starting the
+         * the ACPI interpreter and keels over since IRQ 9 has not been
+         * setup as we had setup IRQ 20 for it).
+         */
+        /* Check whether the GSI != IRQ */
+        if (acpi_gsi_to_irq(gsi, &irq) == 0) {
+                if (irq >= 0 && irq != gsi)
+                        /* Bugger, we MUST have that IRQ. */
+                        gsi_override = irq;
+        }
+
+        gsi = xen_register_gsi(gsi, gsi_override, trigger, polarity);
+        printk(KERN_INFO "xen: acpi sci %d\n", gsi);
+
+        return;
+}
+
+static int acpi_register_gsi_xen(struct device *dev, u32 gsi,
+                                 int trigger, int polarity)
+{
+        return xen_register_gsi(gsi, -1 /* no GSI override */, trigger, polarity);
+}
+
+static int __init pci_xen_initial_domain(void)
+{
+#ifdef CONFIG_PCI_MSI
+        x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs;
+        x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
+#endif
+        xen_setup_acpi_sci();
+        __acpi_register_gsi = acpi_register_gsi_xen;
+
+        return 0;
+}
+
+void __init xen_setup_pirqs(void)
+{
+        int pirq, irq;
+
+        pci_xen_initial_domain();
+
+        if (0 == nr_ioapics) {
+                for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
+                        pirq = xen_allocate_pirq_gsi(irq);
+                        if (WARN(pirq < 0,
+                                 "Could not allocate PIRQ for legacy interrupt\n"))
+                                break;
+                        irq = xen_bind_pirq_gsi_to_irq(irq, pirq, 0, "xt-pic");
+                }
+                return;
+        }
+
+        /* Pre-allocate legacy irqs */
+        for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
+                int trigger, polarity;
+
+                if (acpi_get_override_irq(irq, &trigger, &polarity) == -1)
+                        continue;
+
+                xen_register_pirq(irq, -1 /* no GSI override */,
+                        trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE);
+        }
+}
+#endif
+
+#ifdef CONFIG_XEN_DOM0
+struct xen_device_domain_owner {
+        domid_t domain;
+        struct pci_dev *dev;
+        struct list_head list;
+};
+
+static DEFINE_SPINLOCK(dev_domain_list_spinlock);
+static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list);
+
+static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
+{
+        struct xen_device_domain_owner *owner;
+
+        list_for_each_entry(owner, &dev_domain_list, list) {
+                if (owner->dev == dev)
+                        return owner;
+        }
+        return NULL;
+}
+
+int xen_find_device_domain_owner(struct pci_dev *dev)
+{
+        struct xen_device_domain_owner *owner;
+        int domain = -ENODEV;
+
+        spin_lock(&dev_domain_list_spinlock);
+        owner = find_device(dev);
+        if (owner)
+                domain = owner->domain;
+        spin_unlock(&dev_domain_list_spinlock);
+        return domain;
+}
+EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
+
+int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain)
+{
+        struct xen_device_domain_owner *owner;
+
+        owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL);
+        if (!owner)
+                return -ENODEV;
+
+        spin_lock(&dev_domain_list_spinlock);
+        if (find_device(dev)) {
+                spin_unlock(&dev_domain_list_spinlock);
+                kfree(owner);
+                return -EEXIST;
+        }
+        owner->domain = domain;
+        owner->dev = dev;
+        list_add_tail(&owner->list, &dev_domain_list);
+        spin_unlock(&dev_domain_list_spinlock);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
+
+int xen_unregister_device_domain_owner(struct pci_dev *dev)
+{
+        struct xen_device_domain_owner *owner;
+
+        spin_lock(&dev_domain_list_spinlock);
+        owner = find_device(dev);
+        if (!owner) {
+                spin_unlock(&dev_domain_list_spinlock);
+                return -ENODEV;
+        }
+        list_del(&owner->list);
+        spin_unlock(&dev_domain_list_spinlock);
+        kfree(owner);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);
+#endif