From 48ed12788ed8aa099e463c2febcd3f06fb71c68c Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Tue, 21 Nov 2023 18:03:57 +0000 Subject: iommu: Factor out some helpers The pattern for picking the first device out of the group list is repeated a few times now, so it's clearly worth factoring out, which also helps hide the iommu_group_dev detail from places that don't need to know. Similarly, the safety check for dev_iommu_ops() at certain public interfaces starts looking a bit repetitive, and might not be completely obvious at first glance, so let's factor that out for clarity as well, in preparation for more uses of both. Reviewed-by: Lu Baolu Reviewed-by: Jason Gunthorpe Reviewed-by: Jerry Snitselaar Signed-off-by: Robin Murphy Link: https://lore.kernel.org/r/566cbd161546caa6aed49662c9b3e8f09dc9c3cf.1700589539.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel --- drivers/iommu/iommu.c | 56 ++++++++++++++++++++++++--------------------------- 1 file changed, 26 insertions(+), 30 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index f17a1113f3d6..5c555fc0d54c 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -368,6 +368,15 @@ static void dev_iommu_free(struct device *dev) kfree(param); } +/* + * Internal equivalent of device_iommu_mapped() for when we care that a device + * actually has API ops, and don't want false positives from VFIO-only groups. + */ +static bool dev_has_iommu(struct device *dev) +{ + return dev->iommu && dev->iommu->iommu_dev; +} + static u32 dev_iommu_get_max_pasids(struct device *dev) { u32 max_pasids = 0, bits = 0; @@ -620,7 +629,7 @@ static void __iommu_group_remove_device(struct device *dev) list_del(&device->list); __iommu_group_free_device(group, device); - if (dev->iommu && dev->iommu->iommu_dev) + if (dev_has_iommu(dev)) iommu_deinit_device(dev); else dev->iommu_group = NULL; @@ -819,7 +828,7 @@ int iommu_get_group_resv_regions(struct iommu_group *group, * Non-API groups still expose reserved_regions in sysfs, * so filter out calls that get here that way. */ - if (!device->dev->iommu) + if (!dev_has_iommu(device->dev)) break; INIT_LIST_HEAD(&dev_resv_regions); @@ -1225,6 +1234,12 @@ void iommu_group_remove_device(struct device *dev) } EXPORT_SYMBOL_GPL(iommu_group_remove_device); +static struct device *iommu_group_first_dev(struct iommu_group *group) +{ + lockdep_assert_held(&group->mutex); + return list_first_entry(&group->devices, struct group_device, list)->dev; +} + /** * iommu_group_for_each_dev - iterate over each device in the group * @group: the group @@ -1752,23 +1767,6 @@ __iommu_group_alloc_default_domain(struct iommu_group *group, int req_type) return __iommu_group_domain_alloc(group, req_type); } -/* - * Returns the iommu_ops for the devices in an iommu group. - * - * It is assumed that all devices in an iommu group are managed by a single - * IOMMU unit. Therefore, this returns the dev_iommu_ops of the first device - * in the group. - */ -static const struct iommu_ops *group_iommu_ops(struct iommu_group *group) -{ - struct group_device *device = - list_first_entry(&group->devices, struct group_device, list); - - lockdep_assert_held(&group->mutex); - - return dev_iommu_ops(device->dev); -} - /* * req_type of 0 means "auto" which means to select a domain based on * iommu_def_domain_type or what the driver actually supports. @@ -1776,7 +1774,7 @@ static const struct iommu_ops *group_iommu_ops(struct iommu_group *group) static struct iommu_domain * iommu_group_alloc_default_domain(struct iommu_group *group, int req_type) { - const struct iommu_ops *ops = group_iommu_ops(group); + const struct iommu_ops *ops = dev_iommu_ops(iommu_group_first_dev(group)); struct iommu_domain *dom; lockdep_assert_held(&group->mutex); @@ -1854,7 +1852,7 @@ static int iommu_bus_notifier(struct notifier_block *nb, static int iommu_get_def_domain_type(struct iommu_group *group, struct device *dev, int cur_type) { - const struct iommu_ops *ops = group_iommu_ops(group); + const struct iommu_ops *ops = dev_iommu_ops(dev); int type; if (!ops->def_domain_type) @@ -2021,7 +2019,7 @@ bool device_iommu_capable(struct device *dev, enum iommu_cap cap) { const struct iommu_ops *ops; - if (!dev->iommu || !dev->iommu->iommu_dev) + if (!dev_has_iommu(dev)) return false; ops = dev_iommu_ops(dev); @@ -2120,11 +2118,9 @@ static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops, static struct iommu_domain * __iommu_group_domain_alloc(struct iommu_group *group, unsigned int type) { - struct device *dev = - list_first_entry(&group->devices, struct group_device, list) - ->dev; + struct device *dev = iommu_group_first_dev(group); - return __iommu_domain_alloc(group_iommu_ops(group), dev, type); + return __iommu_domain_alloc(dev_iommu_ops(dev), dev, type); } struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus) @@ -2987,8 +2983,8 @@ EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids); */ int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat) { - if (dev->iommu && dev->iommu->iommu_dev) { - const struct iommu_ops *ops = dev->iommu->iommu_dev->ops; + if (dev_has_iommu(dev)) { + const struct iommu_ops *ops = dev_iommu_ops(dev); if (ops->dev_enable_feat) return ops->dev_enable_feat(dev, feat); @@ -3003,8 +2999,8 @@ EXPORT_SYMBOL_GPL(iommu_dev_enable_feature); */ int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat) { - if (dev->iommu && dev->iommu->iommu_dev) { - const struct iommu_ops *ops = dev->iommu->iommu_dev->ops; + if (dev_has_iommu(dev)) { + const struct iommu_ops *ops = dev_iommu_ops(dev); if (ops->dev_disable_feat) return ops->dev_disable_feat(dev, feat); -- cgit v1.2.3