linux/drivers/iommu/irq_remapping.c
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   1#include <linux/seq_file.h>
   2#include <linux/cpumask.h>
   3#include <linux/kernel.h>
   4#include <linux/string.h>
   5#include <linux/errno.h>
   6#include <linux/msi.h>
   7#include <linux/irq.h>
   8#include <linux/pci.h>
   9
  10#include <asm/hw_irq.h>
  11#include <asm/irq_remapping.h>
  12#include <asm/processor.h>
  13#include <asm/x86_init.h>
  14#include <asm/apic.h>
  15
  16#include "irq_remapping.h"
  17
  18int irq_remapping_enabled;
  19
  20int disable_irq_remap;
  21int irq_remap_broken;
  22int disable_sourceid_checking;
  23int no_x2apic_optout;
  24
  25static struct irq_remap_ops *remap_ops;
  26
  27static int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec);
  28static int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
  29                                  int index, int sub_handle);
  30static int set_remapped_irq_affinity(struct irq_data *data,
  31                                     const struct cpumask *mask,
  32                                     bool force);
  33
  34static bool irq_remapped(struct irq_cfg *cfg)
  35{
  36        return (cfg->remapped == 1);
  37}
  38
  39static void irq_remapping_disable_io_apic(void)
  40{
  41        /*
  42         * With interrupt-remapping, for now we will use virtual wire A
  43         * mode, as virtual wire B is little complex (need to configure
  44         * both IOAPIC RTE as well as interrupt-remapping table entry).
  45         * As this gets called during crash dump, keep this simple for
  46         * now.
  47         */
  48        if (cpu_has_apic || apic_from_smp_config())
  49                disconnect_bsp_APIC(0);
  50}
  51
  52static int do_setup_msi_irqs(struct pci_dev *dev, int nvec)
  53{
  54        int node, ret, sub_handle, index = 0;
  55        unsigned int irq;
  56        struct msi_desc *msidesc;
  57
  58        nvec = __roundup_pow_of_two(nvec);
  59
  60        WARN_ON(!list_is_singular(&dev->msi_list));
  61        msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
  62        WARN_ON(msidesc->irq);
  63        WARN_ON(msidesc->msi_attrib.multiple);
  64
  65        node = dev_to_node(&dev->dev);
  66        irq = __create_irqs(get_nr_irqs_gsi(), nvec, node);
  67        if (irq == 0)
  68                return -ENOSPC;
  69
  70        msidesc->msi_attrib.multiple = ilog2(nvec);
  71        for (sub_handle = 0; sub_handle < nvec; sub_handle++) {
  72                if (!sub_handle) {
  73                        index = msi_alloc_remapped_irq(dev, irq, nvec);
  74                        if (index < 0) {
  75                                ret = index;
  76                                goto error;
  77                        }
  78                } else {
  79                        ret = msi_setup_remapped_irq(dev, irq + sub_handle,
  80                                                     index, sub_handle);
  81                        if (ret < 0)
  82                                goto error;
  83                }
  84                ret = setup_msi_irq(dev, msidesc, irq, sub_handle);
  85                if (ret < 0)
  86                        goto error;
  87        }
  88        return 0;
  89
  90error:
  91        destroy_irqs(irq, nvec);
  92
  93        /*
  94         * Restore altered MSI descriptor fields and prevent just destroyed
  95         * IRQs from tearing down again in default_teardown_msi_irqs()
  96         */
  97        msidesc->irq = 0;
  98        msidesc->msi_attrib.multiple = 0;
  99
 100        return ret;
 101}
 102
 103static int do_setup_msix_irqs(struct pci_dev *dev, int nvec)
 104{
 105        int node, ret, sub_handle, index = 0;
 106        struct msi_desc *msidesc;
 107        unsigned int irq;
 108
 109        node            = dev_to_node(&dev->dev);
 110        irq             = get_nr_irqs_gsi();
 111        sub_handle      = 0;
 112
 113        list_for_each_entry(msidesc, &dev->msi_list, list) {
 114
 115                irq = create_irq_nr(irq, node);
 116                if (irq == 0)
 117                        return -1;
 118
 119                if (sub_handle == 0)
 120                        ret = index = msi_alloc_remapped_irq(dev, irq, nvec);
 121                else
 122                        ret = msi_setup_remapped_irq(dev, irq, index, sub_handle);
 123
 124                if (ret < 0)
 125                        goto error;
 126
 127                ret = setup_msi_irq(dev, msidesc, irq, 0);
 128                if (ret < 0)
 129                        goto error;
 130
 131                sub_handle += 1;
 132                irq        += 1;
 133        }
 134
 135        return 0;
 136
 137error:
 138        destroy_irq(irq);
 139        return ret;
 140}
 141
 142static int irq_remapping_setup_msi_irqs(struct pci_dev *dev,
 143                                        int nvec, int type)
 144{
 145        if (type == PCI_CAP_ID_MSI)
 146                return do_setup_msi_irqs(dev, nvec);
 147        else
 148                return do_setup_msix_irqs(dev, nvec);
 149}
 150
 151void eoi_ioapic_pin_remapped(int apic, int pin, int vector)
 152{
 153        /*
 154         * Intr-remapping uses pin number as the virtual vector
 155         * in the RTE. Actual vector is programmed in
 156         * intr-remapping table entry. Hence for the io-apic
 157         * EOI we use the pin number.
 158         */
 159        io_apic_eoi(apic, pin);
 160}
 161
 162static void __init irq_remapping_modify_x86_ops(void)
 163{
 164        x86_io_apic_ops.disable         = irq_remapping_disable_io_apic;
 165        x86_io_apic_ops.set_affinity    = set_remapped_irq_affinity;
 166        x86_io_apic_ops.setup_entry     = setup_ioapic_remapped_entry;
 167        x86_io_apic_ops.eoi_ioapic_pin  = eoi_ioapic_pin_remapped;
 168        x86_msi.setup_msi_irqs          = irq_remapping_setup_msi_irqs;
 169        x86_msi.setup_hpet_msi          = setup_hpet_msi_remapped;
 170        x86_msi.compose_msi_msg         = compose_remapped_msi_msg;
 171}
 172
 173static __init int setup_nointremap(char *str)
 174{
 175        disable_irq_remap = 1;
 176        return 0;
 177}
 178early_param("nointremap", setup_nointremap);
 179
 180static __init int setup_irqremap(char *str)
 181{
 182        if (!str)
 183                return -EINVAL;
 184
 185        while (*str) {
 186                if (!strncmp(str, "on", 2))
 187                        disable_irq_remap = 0;
 188                else if (!strncmp(str, "off", 3))
 189                        disable_irq_remap = 1;
 190                else if (!strncmp(str, "nosid", 5))
 191                        disable_sourceid_checking = 1;
 192                else if (!strncmp(str, "no_x2apic_optout", 16))
 193                        no_x2apic_optout = 1;
 194
 195                str += strcspn(str, ",");
 196                while (*str == ',')
 197                        str++;
 198        }
 199
 200        return 0;
 201}
 202early_param("intremap", setup_irqremap);
 203
 204void __init setup_irq_remapping_ops(void)
 205{
 206        remap_ops = &intel_irq_remap_ops;
 207
 208#ifdef CONFIG_AMD_IOMMU
 209        if (amd_iommu_irq_ops.prepare() == 0)
 210                remap_ops = &amd_iommu_irq_ops;
 211#endif
 212}
 213
 214void set_irq_remapping_broken(void)
 215{
 216        irq_remap_broken = 1;
 217}
 218
 219int irq_remapping_supported(void)
 220{
 221        if (disable_irq_remap)
 222                return 0;
 223
 224        if (!remap_ops || !remap_ops->supported)
 225                return 0;
 226
 227        return remap_ops->supported();
 228}
 229
 230int __init irq_remapping_prepare(void)
 231{
 232        if (!remap_ops || !remap_ops->prepare)
 233                return -ENODEV;
 234
 235        return remap_ops->prepare();
 236}
 237
 238int __init irq_remapping_enable(void)
 239{
 240        int ret;
 241
 242        if (!remap_ops || !remap_ops->enable)
 243                return -ENODEV;
 244
 245        ret = remap_ops->enable();
 246
 247        if (irq_remapping_enabled)
 248                irq_remapping_modify_x86_ops();
 249
 250        return ret;
 251}
 252
 253void irq_remapping_disable(void)
 254{
 255        if (!irq_remapping_enabled ||
 256            !remap_ops ||
 257            !remap_ops->disable)
 258                return;
 259
 260        remap_ops->disable();
 261}
 262
 263int irq_remapping_reenable(int mode)
 264{
 265        if (!irq_remapping_enabled ||
 266            !remap_ops ||
 267            !remap_ops->reenable)
 268                return 0;
 269
 270        return remap_ops->reenable(mode);
 271}
 272
 273int __init irq_remap_enable_fault_handling(void)
 274{
 275        if (!irq_remapping_enabled)
 276                return 0;
 277
 278        if (!remap_ops || !remap_ops->enable_faulting)
 279                return -ENODEV;
 280
 281        return remap_ops->enable_faulting();
 282}
 283
 284int setup_ioapic_remapped_entry(int irq,
 285                                struct IO_APIC_route_entry *entry,
 286                                unsigned int destination, int vector,
 287                                struct io_apic_irq_attr *attr)
 288{
 289        if (!remap_ops || !remap_ops->setup_ioapic_entry)
 290                return -ENODEV;
 291
 292        return remap_ops->setup_ioapic_entry(irq, entry, destination,
 293                                             vector, attr);
 294}
 295
 296int set_remapped_irq_affinity(struct irq_data *data, const struct cpumask *mask,
 297                              bool force)
 298{
 299        if (!config_enabled(CONFIG_SMP) || !remap_ops ||
 300            !remap_ops->set_affinity)
 301                return 0;
 302
 303        return remap_ops->set_affinity(data, mask, force);
 304}
 305
 306void free_remapped_irq(int irq)
 307{
 308        struct irq_cfg *cfg = irq_get_chip_data(irq);
 309
 310        if (!remap_ops || !remap_ops->free_irq)
 311                return;
 312
 313        if (irq_remapped(cfg))
 314                remap_ops->free_irq(irq);
 315}
 316
 317void compose_remapped_msi_msg(struct pci_dev *pdev,
 318                              unsigned int irq, unsigned int dest,
 319                              struct msi_msg *msg, u8 hpet_id)
 320{
 321        struct irq_cfg *cfg = irq_get_chip_data(irq);
 322
 323        if (!irq_remapped(cfg))
 324                native_compose_msi_msg(pdev, irq, dest, msg, hpet_id);
 325        else if (remap_ops && remap_ops->compose_msi_msg)
 326                remap_ops->compose_msi_msg(pdev, irq, dest, msg, hpet_id);
 327}
 328
 329static int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec)
 330{
 331        if (!remap_ops || !remap_ops->msi_alloc_irq)
 332                return -ENODEV;
 333
 334        return remap_ops->msi_alloc_irq(pdev, irq, nvec);
 335}
 336
 337static int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
 338                                  int index, int sub_handle)
 339{
 340        if (!remap_ops || !remap_ops->msi_setup_irq)
 341                return -ENODEV;
 342
 343        return remap_ops->msi_setup_irq(pdev, irq, index, sub_handle);
 344}
 345
 346int setup_hpet_msi_remapped(unsigned int irq, unsigned int id)
 347{
 348        if (!remap_ops || !remap_ops->setup_hpet_msi)
 349                return -ENODEV;
 350
 351        return remap_ops->setup_hpet_msi(irq, id);
 352}
 353
 354void panic_if_irq_remap(const char *msg)
 355{
 356        if (irq_remapping_enabled)
 357                panic(msg);
 358}
 359
 360static void ir_ack_apic_edge(struct irq_data *data)
 361{
 362        ack_APIC_irq();
 363}
 364
 365static void ir_ack_apic_level(struct irq_data *data)
 366{
 367        ack_APIC_irq();
 368        eoi_ioapic_irq(data->irq, data->chip_data);
 369}
 370
 371static void ir_print_prefix(struct irq_data *data, struct seq_file *p)
 372{
 373        seq_printf(p, " IR-%s", data->chip->name);
 374}
 375
 376void irq_remap_modify_chip_defaults(struct irq_chip *chip)
 377{
 378        chip->irq_print_chip = ir_print_prefix;
 379        chip->irq_ack = ir_ack_apic_edge;
 380        chip->irq_eoi = ir_ack_apic_level;
 381        chip->irq_set_affinity = x86_io_apic_ops.set_affinity;
 382}
 383
 384bool setup_remapped_irq(int irq, struct irq_cfg *cfg, struct irq_chip *chip)
 385{
 386        if (!irq_remapped(cfg))
 387                return false;
 388        irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
 389        irq_remap_modify_chip_defaults(chip);
 390        return true;
 391}
 392
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