diff options
Diffstat (limited to 'drivers/iommu/iommu.c')
| -rw-r--r-- | drivers/iommu/iommu.c | 160 |
1 files changed, 151 insertions, 9 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 9e1b444246f8..c8033ca66377 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -18,6 +18,7 @@ #include <linux/errno.h> #include <linux/host1x_context_bus.h> #include <linux/iommu.h> +#include <linux/iommufd.h> #include <linux/idr.h> #include <linux/err.h> #include <linux/pci.h> @@ -539,6 +540,13 @@ static void iommu_deinit_device(struct device *dev) dev_iommu_free(dev); } +static struct iommu_domain *pasid_array_entry_to_domain(void *entry) +{ + if (xa_pointer_tag(entry) == IOMMU_PASID_ARRAY_DOMAIN) + return xa_untag_pointer(entry); + return ((struct iommu_attach_handle *)xa_untag_pointer(entry))->domain; +} + DEFINE_MUTEX(iommu_probe_device_lock); static int __iommu_probe_device(struct device *dev, struct list_head *group_list) @@ -1973,8 +1981,10 @@ void iommu_set_fault_handler(struct iommu_domain *domain, iommu_fault_handler_t handler, void *token) { - BUG_ON(!domain); + if (WARN_ON(!domain || domain->cookie_type != IOMMU_COOKIE_NONE)) + return; + domain->cookie_type = IOMMU_COOKIE_FAULT_HANDLER; domain->handler = handler; domain->handler_token = token; } @@ -2044,9 +2054,19 @@ EXPORT_SYMBOL_GPL(iommu_paging_domain_alloc_flags); void iommu_domain_free(struct iommu_domain *domain) { - if (domain->type == IOMMU_DOMAIN_SVA) + switch (domain->cookie_type) { + case IOMMU_COOKIE_DMA_IOVA: + iommu_put_dma_cookie(domain); + break; + case IOMMU_COOKIE_DMA_MSI: + iommu_put_msi_cookie(domain); + break; + case IOMMU_COOKIE_SVA: mmdrop(domain->mm); - iommu_put_dma_cookie(domain); + break; + default: + break; + } if (domain->ops->free) domain->ops->free(domain); } @@ -3335,14 +3355,15 @@ static void iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid, } static int __iommu_set_group_pasid(struct iommu_domain *domain, - struct iommu_group *group, ioasid_t pasid) + struct iommu_group *group, ioasid_t pasid, + struct iommu_domain *old) { struct group_device *device, *last_gdev; int ret; for_each_group_device(group, device) { ret = domain->ops->set_dev_pasid(domain, device->dev, - pasid, NULL); + pasid, old); if (ret) goto err_revert; } @@ -3354,7 +3375,15 @@ err_revert: for_each_group_device(group, device) { if (device == last_gdev) break; - iommu_remove_dev_pasid(device->dev, pasid, domain); + /* + * If no old domain, undo the succeeded devices/pasid. + * Otherwise, rollback the succeeded devices/pasid to the old + * domain. And it is a driver bug to fail attaching with a + * previously good domain. + */ + if (!old || WARN_ON(old->ops->set_dev_pasid(old, device->dev, + pasid, domain))) + iommu_remove_dev_pasid(device->dev, pasid, domain); } return ret; } @@ -3376,6 +3405,9 @@ static void __iommu_remove_group_pasid(struct iommu_group *group, * @pasid: the pasid of the device. * @handle: the attach handle. * + * Caller should always provide a new handle to avoid race with the paths + * that have lockless reference to handle if it intends to pass a valid handle. + * * Return: 0 on success, or an error. */ int iommu_attach_device_pasid(struct iommu_domain *domain, @@ -3420,7 +3452,7 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, if (ret) goto out_unlock; - ret = __iommu_set_group_pasid(domain, group, pasid); + ret = __iommu_set_group_pasid(domain, group, pasid, NULL); if (ret) { xa_release(&group->pasid_array, pasid); goto out_unlock; @@ -3441,6 +3473,97 @@ out_unlock: } EXPORT_SYMBOL_GPL(iommu_attach_device_pasid); +/** + * iommu_replace_device_pasid - Replace the domain that a specific pasid + * of the device is attached to + * @domain: the new iommu domain + * @dev: the attached device. + * @pasid: the pasid of the device. + * @handle: the attach handle. + * + * This API allows the pasid to switch domains. The @pasid should have been + * attached. Otherwise, this fails. The pasid will keep the old configuration + * if replacement failed. + * + * Caller should always provide a new handle to avoid race with the paths + * that have lockless reference to handle if it intends to pass a valid handle. + * + * Return 0 on success, or an error. + */ +int iommu_replace_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid, + struct iommu_attach_handle *handle) +{ + /* Caller must be a probed driver on dev */ + struct iommu_group *group = dev->iommu_group; + struct iommu_attach_handle *entry; + struct iommu_domain *curr_domain; + void *curr; + int ret; + + if (!group) + return -ENODEV; + + if (!domain->ops->set_dev_pasid) + return -EOPNOTSUPP; + + if (dev_iommu_ops(dev) != domain->owner || + pasid == IOMMU_NO_PASID || !handle) + return -EINVAL; + + mutex_lock(&group->mutex); + entry = iommu_make_pasid_array_entry(domain, handle); + curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, + XA_ZERO_ENTRY, GFP_KERNEL); + if (xa_is_err(curr)) { + ret = xa_err(curr); + goto out_unlock; + } + + /* + * No domain (with or without handle) attached, hence not + * a replace case. + */ + if (!curr) { + xa_release(&group->pasid_array, pasid); + ret = -EINVAL; + goto out_unlock; + } + + /* + * Reusing handle is problematic as there are paths that refers + * the handle without lock. To avoid race, reject the callers that + * attempt it. + */ + if (curr == entry) { + WARN_ON(1); + ret = -EINVAL; + goto out_unlock; + } + + curr_domain = pasid_array_entry_to_domain(curr); + ret = 0; + + if (curr_domain != domain) { + ret = __iommu_set_group_pasid(domain, group, + pasid, curr_domain); + if (ret) + goto out_unlock; + } + + /* + * The above xa_cmpxchg() reserved the memory, and the + * group->mutex is held, this cannot fail. + */ + WARN_ON(xa_is_err(xa_store(&group->pasid_array, + pasid, entry, GFP_KERNEL))); + +out_unlock: + mutex_unlock(&group->mutex); + return ret; +} +EXPORT_SYMBOL_NS_GPL(iommu_replace_device_pasid, "IOMMUFD_INTERNAL"); + /* * iommu_detach_device_pasid() - Detach the domain from pasid of device * @domain: the iommu domain. @@ -3536,6 +3659,9 @@ EXPORT_SYMBOL_NS_GPL(iommu_attach_handle_get, "IOMMUFD_INTERNAL"); * This is a variant of iommu_attach_group(). It allows the caller to provide * an attach handle and use it when the domain is attached. This is currently * used by IOMMUFD to deliver the I/O page faults. + * + * Caller should always provide a new handle to avoid race with the paths + * that have lockless reference to handle. */ int iommu_attach_group_handle(struct iommu_domain *domain, struct iommu_group *group, @@ -3605,6 +3731,9 @@ EXPORT_SYMBOL_NS_GPL(iommu_detach_group_handle, "IOMMUFD_INTERNAL"); * * If the currently attached domain is a core domain (e.g. a default_domain), * it will act just like the iommu_attach_group_handle(). + * + * Caller should always provide a new handle to avoid race with the paths + * that have lockless reference to handle. */ int iommu_replace_group_handle(struct iommu_group *group, struct iommu_domain *new_domain, @@ -3662,8 +3791,21 @@ int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr) return 0; mutex_lock(&group->mutex); - if (group->domain && group->domain->sw_msi) - ret = group->domain->sw_msi(group->domain, desc, msi_addr); + /* An IDENTITY domain must pass through */ + if (group->domain && group->domain->type != IOMMU_DOMAIN_IDENTITY) { + switch (group->domain->cookie_type) { + case IOMMU_COOKIE_DMA_MSI: + case IOMMU_COOKIE_DMA_IOVA: + ret = iommu_dma_sw_msi(group->domain, desc, msi_addr); + break; + case IOMMU_COOKIE_IOMMUFD: + ret = iommufd_sw_msi(group->domain, desc, msi_addr); + break; + default: + ret = -EOPNOTSUPP; + break; + } + } mutex_unlock(&group->mutex); return ret; } |