diff options
Diffstat (limited to 'drivers/iommu/dmar.c')
| -rw-r--r-- | drivers/iommu/dmar.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c index 6e4d851991f1..bf6bfd1f69aa 100644 --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -194,6 +194,209 @@ void dmar_free_dev_scope(struct pci_dev __rcu ***devices, int *cnt) *cnt = 0; } +/* Optimize out kzalloc()/kfree() for normal cases */ +static char dmar_pci_notify_info_buf[64]; + +static struct dmar_pci_notify_info * +dmar_alloc_pci_notify_info(struct pci_dev *dev, unsigned long event) +{ + int level = 0; + size_t size; + struct pci_dev *tmp; + struct dmar_pci_notify_info *info; + + BUG_ON(dev->is_virtfn); + + /* Only generate path[] for device addition event */ + if (event == BUS_NOTIFY_ADD_DEVICE) + for (tmp = dev; tmp; tmp = tmp->bus->self) + level++; + + size = sizeof(*info) + level * sizeof(struct acpi_dmar_pci_path); + if (size <= sizeof(dmar_pci_notify_info_buf)) { + info = (struct dmar_pci_notify_info *)dmar_pci_notify_info_buf; + } else { + info = kzalloc(size, GFP_KERNEL); + if (!info) { + pr_warn("Out of memory when allocating notify_info " + "for %s.\n", pci_name(dev)); + return NULL; + } + } + + info->event = event; + info->dev = dev; + info->seg = pci_domain_nr(dev->bus); + info->level = level; + if (event == BUS_NOTIFY_ADD_DEVICE) { + for (tmp = dev, level--; tmp; tmp = tmp->bus->self) { + info->path[level].device = PCI_SLOT(tmp->devfn); + info->path[level].function = PCI_FUNC(tmp->devfn); + if (pci_is_root_bus(tmp->bus)) + info->bus = tmp->bus->number; + } + } + + return info; +} + +static inline void dmar_free_pci_notify_info(struct dmar_pci_notify_info *info) +{ + if ((void *)info != dmar_pci_notify_info_buf) + kfree(info); +} + +static bool dmar_match_pci_path(struct dmar_pci_notify_info *info, int bus, + struct acpi_dmar_pci_path *path, int count) +{ + int i; + + if (info->bus != bus) + return false; + if (info->level != count) + return false; + + for (i = 0; i < count; i++) { + if (path[i].device != info->path[i].device || + path[i].function != info->path[i].function) + return false; + } + + return true; +} + +/* Return: > 0 if match found, 0 if no match found, < 0 if error happens */ +int dmar_insert_dev_scope(struct dmar_pci_notify_info *info, + void *start, void*end, u16 segment, + struct pci_dev __rcu **devices, int devices_cnt) +{ + int i, level; + struct pci_dev *tmp, *dev = info->dev; + struct acpi_dmar_device_scope *scope; + struct acpi_dmar_pci_path *path; + + if (segment != info->seg) + return 0; + + for (; start < end; start += scope->length) { + scope = start; + if (scope->entry_type != ACPI_DMAR_SCOPE_TYPE_ENDPOINT && + scope->entry_type != ACPI_DMAR_SCOPE_TYPE_BRIDGE) + continue; + + path = (struct acpi_dmar_pci_path *)(scope + 1); + level = (scope->length - sizeof(*scope)) / sizeof(*path); + if (!dmar_match_pci_path(info, scope->bus, path, level)) + continue; + + if ((scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT) ^ + (dev->hdr_type == PCI_HEADER_TYPE_NORMAL)) { + pr_warn("Device scope type does not match for %s\n", + pci_name(dev)); + return -EINVAL; + } + + for_each_dev_scope(devices, devices_cnt, i, tmp) + if (tmp == NULL) { + rcu_assign_pointer(devices[i], + pci_dev_get(dev)); + return 1; + } + BUG_ON(i >= devices_cnt); + } + + return 0; +} + +int dmar_remove_dev_scope(struct dmar_pci_notify_info *info, u16 segment, + struct pci_dev __rcu **devices, int count) +{ + int index; + struct pci_dev *tmp; + + if (info->seg != segment) + return 0; + + for_each_active_dev_scope(devices, count, index, tmp) + if (tmp == info->dev) { + rcu_assign_pointer(devices[index], NULL); + synchronize_rcu(); + pci_dev_put(tmp); + return 1; + } + + return 0; +} + +static int dmar_pci_bus_add_dev(struct dmar_pci_notify_info *info) +{ + int ret = 0; + struct dmar_drhd_unit *dmaru; + struct acpi_dmar_hardware_unit *drhd; + + for_each_drhd_unit(dmaru) { + if (dmaru->include_all) + continue; + + drhd = container_of(dmaru->hdr, + struct acpi_dmar_hardware_unit, header); + ret = dmar_insert_dev_scope(info, (void *)(drhd + 1), + ((void *)drhd) + drhd->header.length, + dmaru->segment, + dmaru->devices, dmaru->devices_cnt); + if (ret != 0) + break; + } + if (ret >= 0) + ret = dmar_iommu_notify_scope_dev(info); + + return ret; +} + +static void dmar_pci_bus_del_dev(struct dmar_pci_notify_info *info) +{ + struct dmar_drhd_unit *dmaru; + + for_each_drhd_unit(dmaru) + if (dmar_remove_dev_scope(info, dmaru->segment, + dmaru->devices, dmaru->devices_cnt)) + break; + dmar_iommu_notify_scope_dev(info); +} + +static int dmar_pci_bus_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct pci_dev *pdev = to_pci_dev(data); + struct dmar_pci_notify_info *info; + + /* Only care about add/remove events for physical functions */ + if (pdev->is_virtfn) + return NOTIFY_DONE; + if (action != BUS_NOTIFY_ADD_DEVICE && action != BUS_NOTIFY_DEL_DEVICE) + return NOTIFY_DONE; + + info = dmar_alloc_pci_notify_info(pdev, action); + if (!info) + return NOTIFY_DONE; + + down_write(&dmar_global_lock); + if (action == BUS_NOTIFY_ADD_DEVICE) + dmar_pci_bus_add_dev(info); + else if (action == BUS_NOTIFY_DEL_DEVICE) + dmar_pci_bus_del_dev(info); + up_write(&dmar_global_lock); + + dmar_free_pci_notify_info(info); + + return NOTIFY_OK; +} + +static struct notifier_block dmar_pci_bus_nb = { + .notifier_call = dmar_pci_bus_notifier, + .priority = INT_MIN, +}; + /** * dmar_parse_one_drhd - parses exactly one DMA remapping hardware definition * structure which uniquely represent one DMA remapping hardware unit @@ -482,6 +685,8 @@ int __init dmar_dev_scope_init(void) if (ret) goto fail; + bus_register_notifier(&pci_bus_type, &dmar_pci_bus_nb); + dmar_dev_scope_initialized = 1; return 0; @@ -1412,6 +1617,8 @@ static int __init dmar_free_unused_resources(void) if (irq_remapping_enabled || intel_iommu_enabled) return 0; + bus_unregister_notifier(&pci_bus_type, &dmar_pci_bus_nb); + down_write(&dmar_global_lock); list_for_each_entry_safe(dmaru, dmaru_n, &dmar_drhd_units, list) { list_del(&dmaru->list); |