arch/x86/hyperv/irqdomain.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 /*
   4  * Irqdomain for Linux to run as the root partition on Microsoft Hypervisor.
   5  *
   6  * Authors:
   7  *  Sunil Muthuswamy <sunilmut@microsoft.com>
   8  *  Wei Liu <wei.liu@kernel.org>
   9  */
  10
  11 #include <linux/pci.h>
  12 #include <linux/irq.h>
  13 #include <asm/mshyperv.h>
  14
  15 static int hv_map_interrupt(union hv_device_id device_id, bool level,
  16                 int cpu, int vector, struct hv_interrupt_entry *entry)
  17 {
  18         struct hv_input_map_device_interrupt *input;
  19         struct hv_output_map_device_interrupt *output;
  20         struct hv_device_interrupt_descriptor *intr_desc;
  21         unsigned long flags;
  22         u64 status;
  23         int nr_bank, var_size;
  24
  25         local_irq_save(flags);
  26
  27         input = *this_cpu_ptr(hyperv_pcpu_input_arg);
  28         output = *this_cpu_ptr(hyperv_pcpu_output_arg);
  29
  30         intr_desc = &input->interrupt_descriptor;
  31         memset(input, 0, sizeof(*input));
  32         input->partition_id = hv_current_partition_id;
  33         input->device_id = device_id.as_uint64;
  34         intr_desc->interrupt_type = HV_X64_INTERRUPT_TYPE_FIXED;
  35         intr_desc->vector_count = 1;
  36         intr_desc->target.vector = vector;
  37
  38         if (level)
  39                 intr_desc->trigger_mode = HV_INTERRUPT_TRIGGER_MODE_LEVEL;
  40         else
  41                 intr_desc->trigger_mode = HV_INTERRUPT_TRIGGER_MODE_EDGE;
  42
  43         intr_desc->target.vp_set.valid_bank_mask = 0;
  44         intr_desc->target.vp_set.format = HV_GENERIC_SET_SPARSE_4K;
  45         nr_bank = cpumask_to_vpset(&(intr_desc->target.vp_set), cpumask_of(cpu));
  46         if (nr_bank < 0) {
  47                 local_irq_restore(flags);
  48                 pr_err("%s: unable to generate VP set\n", __func__);
  49                 return EINVAL;
  50         }
  51         intr_desc->target.flags = HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET;
  52
  53         /*
  54          * var-sized hypercall, var-size starts after vp_mask (thus
  55          * vp_set.format does not count, but vp_set.valid_bank_mask
  56          * does).
  57          */
  58         var_size = nr_bank + 1;
  59
  60         status = hv_do_rep_hypercall(HVCALL_MAP_DEVICE_INTERRUPT, 0, var_size,
  61                         input, output);
  62         *entry = output->interrupt_entry;
  63
  64         local_irq_restore(flags);
  65
  66         if (!hv_result_success(status))
  67                 pr_err("%s: hypercall failed, status %lld\n", __func__, status);
  68
  69         return hv_result(status);
  70 }
  71
  72 static int hv_unmap_interrupt(u64 id, struct hv_interrupt_entry *old_entry)
  73 {
  74         unsigned long flags;
  75         struct hv_input_unmap_device_interrupt *input;
  76         struct hv_interrupt_entry *intr_entry;
  77         u64 status;
  78
  79         local_irq_save(flags);
  80         input = *this_cpu_ptr(hyperv_pcpu_input_arg);
  81
  82         memset(input, 0, sizeof(*input));
  83         intr_entry = &input->interrupt_entry;
  84         input->partition_id = hv_current_partition_id;
  85         input->device_id = id;
  86         *intr_entry = *old_entry;
  87
  88         status = hv_do_hypercall(HVCALL_UNMAP_DEVICE_INTERRUPT, input, NULL);
  89         local_irq_restore(flags);
  90
  91         return hv_result(status);
  92 }
  93
  94 #ifdef CONFIG_PCI_MSI
  95 struct rid_data {
  96         struct pci_dev *bridge;
  97         u32 rid;
  98 };
  99
 100 static int get_rid_cb(struct pci_dev *pdev, u16 alias, void *data)
 101 {
 102         struct rid_data *rd = data;
 103         u8 bus = PCI_BUS_NUM(rd->rid);
 104
 105         if (pdev->bus->number != bus || PCI_BUS_NUM(alias) != bus) {
 106                 rd->bridge = pdev;
 107                 rd->rid = alias;
 108         }
 109
 110         return 0;
 111 }
 112
 113 static union hv_device_id hv_build_pci_dev_id(struct pci_dev *dev)
 114 {
 115         union hv_device_id dev_id;
 116         struct rid_data data = {
 117                 .bridge = NULL,
 118                 .rid = PCI_DEVID(dev->bus->number, dev->devfn)
 119         };
 120
 121         pci_for_each_dma_alias(dev, get_rid_cb, &data);
 122
 123         dev_id.as_uint64 = 0;
 124         dev_id.device_type = HV_DEVICE_TYPE_PCI;
 125         dev_id.pci.segment = pci_domain_nr(dev->bus);
 126
 127         dev_id.pci.bdf.bus = PCI_BUS_NUM(data.rid);
 128         dev_id.pci.bdf.device = PCI_SLOT(data.rid);
 129         dev_id.pci.bdf.function = PCI_FUNC(data.rid);
 130         dev_id.pci.source_shadow = HV_SOURCE_SHADOW_NONE;
 131
 132         if (data.bridge) {
 133                 int pos;
 134
 135                 /*
 136                  * Microsoft Hypervisor requires a bus range when the bridge is
 137                  * running in PCI-X mode.
 138                  *
 139                  * To distinguish conventional vs PCI-X bridge, we can check
 140                  * the bridge's PCI-X Secondary Status Register, Secondary Bus
 141                  * Mode and Frequency bits. See PCI Express to PCI/PCI-X Bridge
 142                  * Specification Revision 1.0 5.2.2.1.3.
 143                  *
 144                  * Value zero means it is in conventional mode, otherwise it is
 145                  * in PCI-X mode.
 146                  */
 147
 148                 pos = pci_find_capability(data.bridge, PCI_CAP_ID_PCIX);
 149                 if (pos) {
 150                         u16 status;
 151
 152                         pci_read_config_word(data.bridge, pos +
 153                                         PCI_X_BRIDGE_SSTATUS, &status);
 154
 155                         if (status & PCI_X_SSTATUS_FREQ) {
 156                                 /* Non-zero, PCI-X mode */
 157                                 u8 sec_bus, sub_bus;
 158
 159                                 dev_id.pci.source_shadow = HV_SOURCE_SHADOW_BRIDGE_BUS_RANGE;
 160
 161                                 pci_read_config_byte(data.bridge, PCI_SECONDARY_BUS, &sec_bus);
 162                                 dev_id.pci.shadow_bus_range.secondary_bus = sec_bus;
 163                                 pci_read_config_byte(data.bridge, PCI_SUBORDINATE_BUS, &sub_bus);
 164                                 dev_id.pci.shadow_bus_range.subordinate_bus = sub_bus;
 165                         }
 166                 }
 167         }
 168
 169         return dev_id;
 170 }
 171
 172 static int hv_map_msi_interrupt(struct pci_dev *dev, int cpu, int vector,
 173                                 struct hv_interrupt_entry *entry)
 174 {
 175         union hv_device_id device_id = hv_build_pci_dev_id(dev);
 176
 177         return hv_map_interrupt(device_id, false, cpu, vector, entry);
 178 }
 179
 180 static inline void entry_to_msi_msg(struct hv_interrupt_entry *entry, struct msi_msg *msg)
 181 {
 182         /* High address is always 0 */
 183         msg->address_hi = 0;
 184         msg->address_lo = entry->msi_entry.address.as_uint32;
 185         msg->data = entry->msi_entry.data.as_uint32;
 186 }
 187
 188 static int hv_unmap_msi_interrupt(struct pci_dev *dev, struct hv_interrupt_entry *old_entry);
 189 static void hv_irq_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 190 {
 191         struct msi_desc *msidesc;
 192         struct pci_dev *dev;
 193         struct hv_interrupt_entry out_entry, *stored_entry;
 194         struct irq_cfg *cfg = irqd_cfg(data);
 195         cpumask_t *affinity;
 196         int cpu;
 197         u64 status;
 198
 199         msidesc = irq_data_get_msi_desc(data);
 200         dev = msi_desc_to_pci_dev(msidesc);
 201
 202         if (!cfg) {
 203                 pr_debug("%s: cfg is NULL", __func__);
 204                 return;
 205         }
 206
 207         affinity = irq_data_get_effective_affinity_mask(data);
 208         cpu = cpumask_first_and(affinity, cpu_online_mask);
 209
 210         if (data->chip_data) {
 211                 /*
 212                  * This interrupt is already mapped. Let's unmap first.
 213                  *
 214                  * We don't use retarget interrupt hypercalls here because
 215                  * Microsoft Hypervisor doens't allow root to change the vector
 216                  * or specify VPs outside of the set that is initially used
 217                  * during mapping.
 218                  */
 219                 stored_entry = data->chip_data;
 220                 data->chip_data = NULL;
 221
 222                 status = hv_unmap_msi_interrupt(dev, stored_entry);
 223
 224                 kfree(stored_entry);
 225
 226                 if (status != HV_STATUS_SUCCESS) {
 227                         pr_debug("%s: failed to unmap, status %lld", __func__, status);
 228                         return;
 229                 }
 230         }
 231
 232         stored_entry = kzalloc(sizeof(*stored_entry), GFP_ATOMIC);
 233         if (!stored_entry) {
 234                 pr_debug("%s: failed to allocate chip data\n", __func__);
 235                 return;
 236         }
 237
 238         status = hv_map_msi_interrupt(dev, cpu, cfg->vector, &out_entry);
 239         if (status != HV_STATUS_SUCCESS) {
 240                 kfree(stored_entry);
 241                 return;
 242         }
 243
 244         *stored_entry = out_entry;
 245         data->chip_data = stored_entry;
 246         entry_to_msi_msg(&out_entry, msg);
 247
 248         return;
 249 }
 250
 251 static int hv_unmap_msi_interrupt(struct pci_dev *dev, struct hv_interrupt_entry *old_entry)
 252 {
 253         return hv_unmap_interrupt(hv_build_pci_dev_id(dev).as_uint64, old_entry);
 254 }
 255
 256 static void hv_teardown_msi_irq(struct pci_dev *dev, struct irq_data *irqd)
 257 {
 258         struct hv_interrupt_entry old_entry;
 259         struct msi_msg msg;
 260         u64 status;
 261
 262         if (!irqd->chip_data) {
 263                 pr_debug("%s: no chip data\n!", __func__);
 264                 return;
 265         }
 266
 267         old_entry = *(struct hv_interrupt_entry *)irqd->chip_data;
 268         entry_to_msi_msg(&old_entry, &msg);
 269
 270         kfree(irqd->chip_data);
 271         irqd->chip_data = NULL;
 272
 273         status = hv_unmap_msi_interrupt(dev, &old_entry);
 274
 275         if (status != HV_STATUS_SUCCESS)
 276                 pr_err("%s: hypercall failed, status %lld\n", __func__, status);
 277 }
 278
 279 static void hv_msi_free_irq(struct irq_domain *domain,
 280                             struct msi_domain_info *info, unsigned int virq)
 281 {
 282         struct irq_data *irqd = irq_get_irq_data(virq);
 283         struct msi_desc *desc;
 284
 285         if (!irqd)
 286                 return;
 287
 288         desc = irq_data_get_msi_desc(irqd);
 289         if (!desc || !desc->irq || WARN_ON_ONCE(!dev_is_pci(desc->dev)))
 290                 return;
 291
 292         hv_teardown_msi_irq(to_pci_dev(desc->dev), irqd);
 293 }
 294
 295 /*
 296  * IRQ Chip for MSI PCI/PCI-X/PCI-Express Devices,
 297  * which implement the MSI or MSI-X Capability Structure.
 298  */
 299 static struct irq_chip hv_pci_msi_controller = {
 300         .name                   = "HV-PCI-MSI",
 301         .irq_unmask             = pci_msi_unmask_irq,
 302         .irq_mask               = pci_msi_mask_irq,
 303         .irq_ack                = irq_chip_ack_parent,
 304         .irq_retrigger          = irq_chip_retrigger_hierarchy,
 305         .irq_compose_msi_msg    = hv_irq_compose_msi_msg,
 306         .irq_set_affinity       = msi_domain_set_affinity,
 307         .flags                  = IRQCHIP_SKIP_SET_WAKE,
 308 };
 309
 310 static struct msi_domain_ops pci_msi_domain_ops = {
 311         .msi_free               = hv_msi_free_irq,
 312         .msi_prepare            = pci_msi_prepare,
 313 };
 314
 315 static struct msi_domain_info hv_pci_msi_domain_info = {
 316         .flags          = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
 317                           MSI_FLAG_PCI_MSIX,
 318         .ops            = &pci_msi_domain_ops,
 319         .chip           = &hv_pci_msi_controller,
 320         .handler        = handle_edge_irq,
 321         .handler_name   = "edge",
 322 };
 323
 324 struct irq_domain * __init hv_create_pci_msi_domain(void)
 325 {
 326         struct irq_domain *d = NULL;
 327         struct fwnode_handle *fn;
 328
 329         fn = irq_domain_alloc_named_fwnode("HV-PCI-MSI");
 330         if (fn)
 331                 d = pci_msi_create_irq_domain(fn, &hv_pci_msi_domain_info, x86_vector_domain);
 332
 333         /* No point in going further if we can't get an irq domain */
 334         BUG_ON(!d);
 335
 336         return d;
 337 }
 338
 339 #endif /* CONFIG_PCI_MSI */
 340
 341 int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry)
 342 {
 343         union hv_device_id device_id;
 344
 345         device_id.as_uint64 = 0;
 346         device_id.device_type = HV_DEVICE_TYPE_IOAPIC;
 347         device_id.ioapic.ioapic_id = (u8)ioapic_id;
 348
 349         return hv_unmap_interrupt(device_id.as_uint64, entry);
 350 }
 351 EXPORT_SYMBOL_GPL(hv_unmap_ioapic_interrupt);
 352
 353 int hv_map_ioapic_interrupt(int ioapic_id, bool level, int cpu, int vector,
 354                 struct hv_interrupt_entry *entry)
 355 {
 356         union hv_device_id device_id;
 357
 358         device_id.as_uint64 = 0;
 359         device_id.device_type = HV_DEVICE_TYPE_IOAPIC;
 360         device_id.ioapic.ioapic_id = (u8)ioapic_id;
 361
 362         return hv_map_interrupt(device_id, level, cpu, vector, entry);
 363 }
 364 EXPORT_SYMBOL_GPL(hv_map_ioapic_interrupt);