With dev_def_domain_type introduced, iommu default domain framework is now able to determine a proper default domain for a group. Let's use this to configure a group's default domain.
If unlikely a device requires a special default domain type other than that in use, iommu probe procedure will either allocate a new domain according to the specified domain type, or (if the group has other devices sitting in it) change the default domain. The vendor iommu driver which exposes the dev_def_domain_type callback should guarantee that there're no multiple devices belonging to a same group requires differnt types of default domain. Signed-off-by: Sai Praneeth Prakhya <[email protected]> Signed-off-by: Lu Baolu <[email protected]> --- drivers/iommu/iommu.c | 93 +++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 90 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 3e3528436e0b..095e0bc563c4 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1361,6 +1361,79 @@ struct iommu_group *fsl_mc_device_group(struct device *dev) } EXPORT_SYMBOL_GPL(fsl_mc_device_group); +/** + * Changes the default domain of a group + * + * @group: The group for which the default domain should be changed + * @type: The new default domain type + * + * The caller should hold the group->mutex before call into this function. + * Returns 0 on success and error code on failure. + */ +static int iommu_group_change_def_domain(struct iommu_group *group, int type) +{ + struct group_device *grp_dev, *temp; + struct iommu_domain *new, *old; + const struct iommu_ops *ops; + int ret = 0; + + if ((type != IOMMU_DOMAIN_IDENTITY && type != IOMMU_DOMAIN_DMA) || + !group->default_domain || type == group->default_domain->type || + !group->default_domain->ops) + return -EINVAL; + + if (group->domain != group->default_domain) + return -EBUSY; + + iommu_group_ref_get(group); + old = group->default_domain; + ops = group->default_domain->ops; + + /* Allocate a new domain of requested type. */ + new = ops->domain_alloc(type); + if (!new) { + ret = -ENOMEM; + goto domain_out; + } + new->type = type; + new->ops = ops; + new->pgsize_bitmap = group->default_domain->pgsize_bitmap; + + group->default_domain = new; + group->domain = new; + list_for_each_entry_safe(grp_dev, temp, &group->devices, list) { + struct device *dev; + + dev = grp_dev->dev; + if (device_is_bound(dev)) { + ret = -EINVAL; + goto device_out; + } + + iommu_group_create_direct_mappings(group, dev); + ret = __iommu_attach_device(group->domain, dev); + if (ret) + goto device_out; + + ret = ops->add_device(dev); + if (ret) + goto device_out; + } + + iommu_group_put(group); + iommu_domain_free(old); + + return 0; + +device_out: + group->default_domain = old; + __iommu_attach_group(old, group); + iommu_domain_free(new); +domain_out: + iommu_group_put(group); + return ret; +} + /** * iommu_group_get_for_dev - Find or create the IOMMU group for a device * @dev: target device @@ -1375,6 +1448,7 @@ struct iommu_group *iommu_group_get_for_dev(struct device *dev) { const struct iommu_ops *ops = dev->bus->iommu_ops; struct iommu_group *group; + int dev_def_type = 0; int ret; group = iommu_group_get(dev); @@ -1391,20 +1465,24 @@ struct iommu_group *iommu_group_get_for_dev(struct device *dev) if (IS_ERR(group)) return group; + if (ops->dev_def_domain_type) + dev_def_type = ops->dev_def_domain_type(dev); + /* * Try to allocate a default domain - needs support from the * IOMMU driver. */ if (!group->default_domain) { struct iommu_domain *dom; + int type = dev_def_type ? : iommu_def_domain_type; - dom = __iommu_domain_alloc(dev->bus, iommu_def_domain_type); - if (!dom && iommu_def_domain_type != IOMMU_DOMAIN_DMA) { + dom = __iommu_domain_alloc(dev->bus, type); + if (!dom && type != IOMMU_DOMAIN_DMA) { dom = __iommu_domain_alloc(dev->bus, IOMMU_DOMAIN_DMA); if (dom) { dev_warn(dev, "failed to allocate default IOMMU domain of type %u; falling back to IOMMU_DOMAIN_DMA", - iommu_def_domain_type); + type); } } @@ -1418,6 +1496,15 @@ struct iommu_group *iommu_group_get_for_dev(struct device *dev) DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE, &attr); } + } else if (dev_def_type && + dev_def_type != group->default_domain->type) { + mutex_lock(&group->mutex); + ret = iommu_group_change_def_domain(group, dev_def_type); + mutex_unlock(&group->mutex); + if (ret) { + iommu_group_put(group); + return ERR_PTR(ret); + } } ret = iommu_group_add_device(group, dev); -- 2.17.1 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
