arch/x86/pci/xen.c

   1 /*
   2  * Xen PCI Frontend Stub - puts some "dummy" functions in to the Linux
   3  *                         x86 PCI core to support the Xen PCI Frontend
   4  *
   5  *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
   6  */
   7 #include <linux/module.h>
   8 #include <linux/init.h>
   9 #include <linux/pci.h>
  10 #include <linux/acpi.h>
  11
  12 #include <linux/io.h>
  13 #include <asm/pci_x86.h>
  14
  15 #include <asm/xen/hypervisor.h>
  16
  17 #include <xen/events.h>
  18 #include <asm/xen/pci.h>
  19
  20 #ifdef CONFIG_ACPI
  21 static int xen_hvm_register_pirq(u32 gsi, int triggering)
  22 {
  23         int rc, irq;
  24         struct physdev_map_pirq map_irq;
  25         int shareable = 0;
  26         char *name;
  27
  28         if (!xen_hvm_domain())
  29                 return -1;
  30
  31         map_irq.domid = DOMID_SELF;
  32         map_irq.type = MAP_PIRQ_TYPE_GSI;
  33         map_irq.index = gsi;
  34         map_irq.pirq = -1;
  35
  36         rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
  37         if (rc) {
  38                 printk(KERN_WARNING "xen map irq failed %d\n", rc);
  39                 return -1;
  40         }
  41
  42         if (triggering == ACPI_EDGE_SENSITIVE) {
  43                 shareable = 0;
  44                 name = "ioapic-edge";
  45         } else {
  46                 shareable = 1;
  47                 name = "ioapic-level";
  48         }
  49
  50         irq = xen_map_pirq_gsi(map_irq.pirq, gsi, shareable, name);
  51
  52         printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
  53
  54         return irq;
  55 }
  56
  57 static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
  58                                  int trigger, int polarity)
  59 {
  60         return xen_hvm_register_pirq(gsi, trigger);
  61 }
  62 #endif
  63
  64 #if defined(CONFIG_PCI_MSI)
  65 #include <linux/msi.h>
  66
  67 struct xen_pci_frontend_ops *xen_pci_frontend;
  68 EXPORT_SYMBOL_GPL(xen_pci_frontend);
  69
  70 /*
  71  * For MSI interrupts we have to use drivers/xen/event.s functions to
  72  * allocate an irq_desc and setup the right */
  73
  74
  75 static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
  76 {
  77         int irq, ret, i;
  78         struct msi_desc *msidesc;
  79         int *v;
  80
  81         v = kzalloc(sizeof(int) * max(1, nvec), GFP_KERNEL);
  82         if (!v)
  83                 return -ENOMEM;
  84
  85         if (!xen_initial_domain()) {
  86                 if (type == PCI_CAP_ID_MSIX)
  87                         ret = xen_pci_frontend_enable_msix(dev, &v, nvec);
  88                 else
  89                         ret = xen_pci_frontend_enable_msi(dev, &v);
  90                 if (ret)
  91                         goto error;
  92         }
  93         i = 0;
  94         list_for_each_entry(msidesc, &dev->msi_list, list) {
  95                 irq = xen_allocate_pirq(v[i], 0, /* not sharable */
  96                         (type == PCI_CAP_ID_MSIX) ?
  97                         "pcifront-msi-x" : "pcifront-msi");
  98                 if (irq < 0)
  99                         return -1;
 100
 101                 ret = set_irq_msi(irq, msidesc);
 102                 if (ret)
 103                         goto error_while;
 104                 i++;
 105         }
 106         kfree(v);
 107         return 0;
 108
 109 error_while:
 110         unbind_from_irqhandler(irq, NULL);
 111 error:
 112         if (ret == -ENODEV)
 113                 dev_err(&dev->dev, "Xen PCI frontend has not registered" \
 114                         " MSI/MSI-X support!\n");
 115
 116         kfree(v);
 117         return ret;
 118 }
 119
 120 static void xen_teardown_msi_irqs(struct pci_dev *dev)
 121 {
 122         /* Only do this when were are in non-privileged mode.*/
 123         if (!xen_initial_domain()) {
 124                 struct msi_desc *msidesc;
 125
 126                 msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
 127                 if (msidesc->msi_attrib.is_msix)
 128                         xen_pci_frontend_disable_msix(dev);
 129                 else
 130                         xen_pci_frontend_disable_msi(dev);
 131         }
 132
 133 }
 134
 135 static void xen_teardown_msi_irq(unsigned int irq)
 136 {
 137         xen_destroy_irq(irq);
 138 }
 139 #endif
 140
 141 static int xen_pcifront_enable_irq(struct pci_dev *dev)
 142 {
 143         int rc;
 144         int share = 1;
 145
 146         dev_info(&dev->dev, "Xen PCI enabling IRQ: %d\n", dev->irq);
 147
 148         if (dev->irq < 0)
 149                 return -EINVAL;
 150
 151         if (dev->irq < NR_IRQS_LEGACY)
 152                 share = 0;
 153
 154         rc = xen_allocate_pirq(dev->irq, share, "pcifront");
 155         if (rc < 0) {
 156                 dev_warn(&dev->dev, "Xen PCI IRQ: %d, failed to register:%d\n",
 157                          dev->irq, rc);
 158                 return rc;
 159         }
 160         return 0;
 161 }
 162
 163 int __init pci_xen_init(void)
 164 {
 165         if (!xen_pv_domain() || xen_initial_domain())
 166                 return -ENODEV;
 167
 168         printk(KERN_INFO "PCI: setting up Xen PCI frontend stub\n");
 169
 170         pcibios_set_cache_line_size();
 171
 172         pcibios_enable_irq = xen_pcifront_enable_irq;
 173         pcibios_disable_irq = NULL;
 174
 175 #ifdef CONFIG_ACPI
 176         /* Keep ACPI out of the picture */
 177         acpi_noirq = 1;
 178 #endif
 179
 180 #ifdef CONFIG_PCI_MSI
 181         x86_msi.setup_msi_irqs = xen_setup_msi_irqs;
 182         x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
 183         x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs;
 184 #endif
 185         return 0;
 186 }