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/io_apic.h>
  14 #include <asm/pci_x86.h>
  15
  16 #include <asm/xen/hypervisor.h>
  17
  18 #include <xen/features.h>
  19 #include <xen/events.h>
  20 #include <asm/xen/pci.h>
  21
  22 #ifdef CONFIG_ACPI
  23 static int xen_hvm_register_pirq(u32 gsi, int triggering)
  24 {
  25         int rc, irq;
  26         struct physdev_map_pirq map_irq;
  27         int shareable = 0;
  28         char *name;
  29
  30         if (!xen_hvm_domain())
  31                 return -1;
  32
  33         map_irq.domid = DOMID_SELF;
  34         map_irq.type = MAP_PIRQ_TYPE_GSI;
  35         map_irq.index = gsi;
  36         map_irq.pirq = -1;
  37
  38         rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
  39         if (rc) {
  40                 printk(KERN_WARNING "xen map irq failed %d\n", rc);
  41                 return -1;
  42         }
  43
  44         if (triggering == ACPI_EDGE_SENSITIVE) {
  45                 shareable = 0;
  46                 name = "ioapic-edge";
  47         } else {
  48                 shareable = 1;
  49                 name = "ioapic-level";
  50         }
  51
  52         irq = xen_map_pirq_gsi(map_irq.pirq, gsi, shareable, name);
  53
  54         printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
  55
  56         return irq;
  57 }
  58
  59 static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
  60                                  int trigger, int polarity)
  61 {
  62         return xen_hvm_register_pirq(gsi, trigger);
  63 }
  64 #endif
  65
  66 #if defined(CONFIG_PCI_MSI)
  67 #include <linux/msi.h>
  68 #include <asm/msidef.h>
  69
  70 struct xen_pci_frontend_ops *xen_pci_frontend;
  71 EXPORT_SYMBOL_GPL(xen_pci_frontend);
  72
  73 #define XEN_PIRQ_MSI_DATA  (MSI_DATA_TRIGGER_EDGE | \
  74                 MSI_DATA_LEVEL_ASSERT | (3 << 8) | MSI_DATA_VECTOR(0))
  75
  76 static void xen_msi_compose_msg(struct pci_dev *pdev, unsigned int pirq,
  77                 struct msi_msg *msg)
  78 {
  79         /* We set vector == 0 to tell the hypervisor we don't care about it,
  80          * but we want a pirq setup instead.
  81          * We use the dest_id field to pass the pirq that we want. */
  82         msg->address_hi = MSI_ADDR_BASE_HI | MSI_ADDR_EXT_DEST_ID(pirq);
  83         msg->address_lo =
  84                 MSI_ADDR_BASE_LO |
  85                 MSI_ADDR_DEST_MODE_PHYSICAL |
  86                 MSI_ADDR_REDIRECTION_CPU |
  87                 MSI_ADDR_DEST_ID(pirq);
  88
  89         msg->data = XEN_PIRQ_MSI_DATA;
  90 }
  91
  92 static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
  93 {
  94         int irq, pirq, ret = 0;
  95         struct msi_desc *msidesc;
  96         struct msi_msg msg;
  97
  98         list_for_each_entry(msidesc, &dev->msi_list, list) {
  99                 __read_msi_msg(msidesc, &msg);
 100                 pirq = MSI_ADDR_EXT_DEST_ID(msg.address_hi) |
 101                         ((msg.address_lo >> MSI_ADDR_DEST_ID_SHIFT) & 0xff);
 102                 if (xen_irq_from_pirq(pirq) >= 0 && msg.data == XEN_PIRQ_MSI_DATA) {
 103                         xen_allocate_pirq_msi((type == PCI_CAP_ID_MSIX) ?
 104                                         "msi-x" : "msi", &irq, &pirq, XEN_ALLOC_IRQ);
 105                         if (irq < 0)
 106                                 goto error;
 107                         ret = set_irq_msi(irq, msidesc);
 108                         if (ret < 0)
 109                                 goto error_while;
 110                         printk(KERN_DEBUG "xen: msi already setup: msi --> irq=%d"
 111                                         " pirq=%d\n", irq, pirq);
 112                         return 0;
 113                 }
 114                 xen_allocate_pirq_msi((type == PCI_CAP_ID_MSIX) ?
 115                                 "msi-x" : "msi", &irq, &pirq, (XEN_ALLOC_IRQ | XEN_ALLOC_PIRQ));
 116                 if (irq < 0 || pirq < 0)
 117                         goto error;
 118                 printk(KERN_DEBUG "xen: msi --> irq=%d, pirq=%d\n", irq, pirq);
 119                 xen_msi_compose_msg(dev, pirq, &msg);
 120                 ret = set_irq_msi(irq, msidesc);
 121                 if (ret < 0)
 122                         goto error_while;
 123                 write_msi_msg(irq, &msg);
 124         }
 125         return 0;
 126
 127 error_while:
 128         unbind_from_irqhandler(irq, NULL);
 129 error:
 130         if (ret == -ENODEV)
 131                 dev_err(&dev->dev, "Xen PCI frontend has not registered" \
 132                                 " MSI/MSI-X support!\n");
 133
 134         return ret;
 135 }
 136
 137 /*
 138  * For MSI interrupts we have to use drivers/xen/event.s functions to
 139  * allocate an irq_desc and setup the right */
 140
 141
 142 static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 143 {
 144         int irq, ret, i;
 145         struct msi_desc *msidesc;
 146         int *v;
 147
 148         v = kzalloc(sizeof(int) * max(1, nvec), GFP_KERNEL);
 149         if (!v)
 150                 return -ENOMEM;
 151
 152         if (type == PCI_CAP_ID_MSIX)
 153                 ret = xen_pci_frontend_enable_msix(dev, &v, nvec);
 154         else
 155                 ret = xen_pci_frontend_enable_msi(dev, &v);
 156         if (ret)
 157                 goto error;
 158         i = 0;
 159         list_for_each_entry(msidesc, &dev->msi_list, list) {
 160                 irq = xen_allocate_pirq(v[i], 0, /* not sharable */
 161                         (type == PCI_CAP_ID_MSIX) ?
 162                         "pcifront-msi-x" : "pcifront-msi");
 163                 if (irq < 0) {
 164                         ret = -1;
 165                         goto free;
 166                 }
 167
 168                 ret = set_irq_msi(irq, msidesc);
 169                 if (ret)
 170                         goto error_while;
 171                 i++;
 172         }
 173         kfree(v);
 174         return 0;
 175
 176 error_while:
 177         unbind_from_irqhandler(irq, NULL);
 178 error:
 179         if (ret == -ENODEV)
 180                 dev_err(&dev->dev, "Xen PCI frontend has not registered" \
 181                         " MSI/MSI-X support!\n");
 182 free:
 183         kfree(v);
 184         return ret;
 185 }
 186
 187 static void xen_teardown_msi_irqs(struct pci_dev *dev)
 188 {
 189         struct msi_desc *msidesc;
 190
 191         msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
 192         if (msidesc->msi_attrib.is_msix)
 193                 xen_pci_frontend_disable_msix(dev);
 194         else
 195                 xen_pci_frontend_disable_msi(dev);
 196 }
 197
 198 static void xen_teardown_msi_irq(unsigned int irq)
 199 {
 200         xen_destroy_irq(irq);
 201 }
 202
 203 static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 204 {
 205         int irq, ret;
 206         struct msi_desc *msidesc;
 207
 208         list_for_each_entry(msidesc, &dev->msi_list, list) {
 209                 irq = xen_create_msi_irq(dev, msidesc, type);
 210                 if (irq < 0)
 211                         return -1;
 212
 213                 ret = set_irq_msi(irq, msidesc);
 214                 if (ret)
 215                         goto error;
 216         }
 217         return 0;
 218
 219 error:
 220         xen_destroy_irq(irq);
 221         return ret;
 222 }
 223 #endif
 224
 225 static int xen_pcifront_enable_irq(struct pci_dev *dev)
 226 {
 227         int rc;
 228         int share = 1;
 229
 230         dev_info(&dev->dev, "Xen PCI enabling IRQ: %d\n", dev->irq);
 231
 232         if (dev->irq < 0)
 233                 return -EINVAL;
 234
 235         if (dev->irq < NR_IRQS_LEGACY)
 236                 share = 0;
 237
 238         rc = xen_allocate_pirq(dev->irq, share, "pcifront");
 239         if (rc < 0) {
 240                 dev_warn(&dev->dev, "Xen PCI IRQ: %d, failed to register:%d\n",
 241                          dev->irq, rc);
 242                 return rc;
 243         }
 244         return 0;
 245 }
 246
 247 int __init pci_xen_init(void)
 248 {
 249         if (!xen_pv_domain() || xen_initial_domain())
 250                 return -ENODEV;
 251
 252         printk(KERN_INFO "PCI: setting up Xen PCI frontend stub\n");
 253
 254         pcibios_set_cache_line_size();
 255
 256         pcibios_enable_irq = xen_pcifront_enable_irq;
 257         pcibios_disable_irq = NULL;
 258
 259 #ifdef CONFIG_ACPI
 260         /* Keep ACPI out of the picture */
 261         acpi_noirq = 1;
 262 #endif
 263
 264 #ifdef CONFIG_PCI_MSI
 265         x86_msi.setup_msi_irqs = xen_setup_msi_irqs;
 266         x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
 267         x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs;
 268 #endif
 269         return 0;
 270 }
 271
 272 int __init pci_xen_hvm_init(void)
 273 {
 274         if (!xen_feature(XENFEAT_hvm_pirqs))
 275                 return 0;
 276
 277 #ifdef CONFIG_ACPI
 278         /*
 279          * We don't want to change the actual ACPI delivery model,
 280          * just how GSIs get registered.
 281          */
 282         __acpi_register_gsi = acpi_register_gsi_xen_hvm;
 283 #endif
 284
 285 #ifdef CONFIG_PCI_MSI
 286         x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs;
 287         x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
 288 #endif
 289         return 0;
 290 }
 291
 292 #ifdef CONFIG_XEN_DOM0
 293 static int xen_register_pirq(u32 gsi, int triggering)
 294 {
 295         int rc, irq;
 296         struct physdev_map_pirq map_irq;
 297         int shareable = 0;
 298         char *name;
 299
 300         if (!xen_pv_domain())
 301                 return -1;
 302
 303         if (triggering == ACPI_EDGE_SENSITIVE) {
 304                 shareable = 0;
 305                 name = "ioapic-edge";
 306         } else {
 307                 shareable = 1;
 308                 name = "ioapic-level";
 309         }
 310
 311         irq = xen_allocate_pirq(gsi, shareable, name);
 312
 313         printk(KERN_DEBUG "xen: --> irq=%d\n", irq);
 314
 315         if (irq < 0)
 316                 goto out;
 317
 318         map_irq.domid = DOMID_SELF;
 319         map_irq.type = MAP_PIRQ_TYPE_GSI;
 320         map_irq.index = gsi;
 321         map_irq.pirq = irq;
 322
 323         rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
 324         if (rc) {
 325                 printk(KERN_WARNING "xen map irq failed %d\n", rc);
 326                 return -1;
 327         }
 328
 329 out:
 330         return irq;
 331 }
 332
 333 static int xen_register_gsi(u32 gsi, int triggering, int polarity)
 334 {
 335         int rc, irq;
 336         struct physdev_setup_gsi setup_gsi;
 337
 338         if (!xen_pv_domain())
 339                 return -1;
 340
 341         printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n",
 342                         gsi, triggering, polarity);
 343
 344         irq = xen_register_pirq(gsi, triggering);
 345
 346         setup_gsi.gsi = gsi;
 347         setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1);
 348         setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
 349
 350         rc = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
 351         if (rc == -EEXIST)
 352                 printk(KERN_INFO "Already setup the GSI :%d\n", gsi);
 353         else if (rc) {
 354                 printk(KERN_ERR "Failed to setup GSI :%d, err_code:%d\n",
 355                                 gsi, rc);
 356         }
 357
 358         return irq;
 359 }
 360
 361 static __init void xen_setup_acpi_sci(void)
 362 {
 363         int rc;
 364         int trigger, polarity;
 365         int gsi = acpi_sci_override_gsi;
 366
 367         if (!gsi)
 368                 return;
 369
 370         rc = acpi_get_override_irq(gsi, &trigger, &polarity);
 371         if (rc) {
 372                 printk(KERN_WARNING "xen: acpi_get_override_irq failed for acpi"
 373                                 " sci, rc=%d\n", rc);
 374                 return;
 375         }
 376         trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
 377         polarity = polarity ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
 378
 379         printk(KERN_INFO "xen: sci override: global_irq=%d trigger=%d "
 380                         "polarity=%d\n", gsi, trigger, polarity);
 381
 382         gsi = xen_register_gsi(gsi, trigger, polarity);
 383         printk(KERN_INFO "xen: acpi sci %d\n", gsi);
 384
 385         return;
 386 }
 387
 388 static int acpi_register_gsi_xen(struct device *dev, u32 gsi,
 389                                  int trigger, int polarity)
 390 {
 391         return xen_register_gsi(gsi, trigger, polarity);
 392 }
 393
 394 static int __init pci_xen_initial_domain(void)
 395 {
 396 #ifdef CONFIG_PCI_MSI
 397         x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs;
 398         x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
 399 #endif
 400         xen_setup_acpi_sci();
 401         __acpi_register_gsi = acpi_register_gsi_xen;
 402
 403         return 0;
 404 }
 405
 406 void __init xen_setup_pirqs(void)
 407 {
 408         int irq;
 409
 410         pci_xen_initial_domain();
 411
 412         if (0 == nr_ioapics) {
 413                 for (irq = 0; irq < NR_IRQS_LEGACY; irq++)
 414                         xen_allocate_pirq(irq, 0, "xt-pic");
 415                 return;
 416         }
 417
 418         /* Pre-allocate legacy irqs */
 419         for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
 420                 int trigger, polarity;
 421
 422                 if (acpi_get_override_irq(irq, &trigger, &polarity) == -1)
 423                         continue;
 424
 425                 xen_register_pirq(irq,
 426                         trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE);
 427         }
 428 }
 429 #endif