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authorLu Baolu <baolu.lu@linux.intel.com>2022-10-31 08:59:09 +0800
committerJoerg Roedel <jroedel@suse.de>2022-11-03 15:47:47 +0100
commit16603704559c7a68718059c4f75287886c01b20f (patch)
tree111f52cb8fc1cd151eb1554c22f798b44495efbd /drivers/iommu/iommu.c
parent201007ef707a8bb5592cd07dd46fc9222c48e0b9 (diff)
downloadlinux-16603704559c7a68718059c4f75287886c01b20f.tar.bz2
iommu: Add attach/detach_dev_pasid iommu interfaces
Attaching an IOMMU domain to a PASID of a device is a generic operation for modern IOMMU drivers which support PASID-granular DMA address translation. Currently visible usage scenarios include (but not limited): - SVA (Shared Virtual Address) - kernel DMA with PASID - hardware-assist mediated device This adds the set_dev_pasid domain ops for setting the domain onto a PASID of a device and remove_dev_pasid iommu ops for removing any setup on a PASID of device. This also adds interfaces for device drivers to attach/detach/retrieve a domain for a PASID of a device. If multiple devices share a single group, it's fine as long the fabric always routes every TLP marked with a PASID to the host bridge and only the host bridge. For example, ACS achieves this universally and has been checked when pci_enable_pasid() is called. As we can't reliably tell the source apart in a group, all the devices in a group have to be considered as the same source, and mapped to the same PASID table. The DMA ownership is about the whole device (more precisely, iommu group), including the RID and PASIDs. When the ownership is converted, the pasid array must be empty. This also adds necessary checks in the DMA ownership interfaces. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Yi Liu <yi.l.liu@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org> Tested-by: Tony Zhu <tony.zhu@intel.com> Link: https://lore.kernel.org/r/20221031005917.45690-6-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/iommu.c')
-rw-r--r--drivers/iommu/iommu.c141
1 files changed, 137 insertions, 4 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index a94ec648c88b..bf22992beb98 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -43,6 +43,7 @@ struct iommu_group {
struct kobject kobj;
struct kobject *devices_kobj;
struct list_head devices;
+ struct xarray pasid_array;
struct mutex mutex;
void *iommu_data;
void (*iommu_data_release)(void *iommu_data);
@@ -723,6 +724,7 @@ struct iommu_group *iommu_group_alloc(void)
mutex_init(&group->mutex);
INIT_LIST_HEAD(&group->devices);
INIT_LIST_HEAD(&group->entry);
+ xa_init(&group->pasid_array);
ret = ida_alloc(&iommu_group_ida, GFP_KERNEL);
if (ret < 0) {
@@ -3106,7 +3108,8 @@ int iommu_device_use_default_domain(struct device *dev)
mutex_lock(&group->mutex);
if (group->owner_cnt) {
- if (group->owner || !iommu_is_default_domain(group)) {
+ if (group->owner || !iommu_is_default_domain(group) ||
+ !xa_empty(&group->pasid_array)) {
ret = -EBUSY;
goto unlock_out;
}
@@ -3137,7 +3140,7 @@ void iommu_device_unuse_default_domain(struct device *dev)
return;
mutex_lock(&group->mutex);
- if (!WARN_ON(!group->owner_cnt))
+ if (!WARN_ON(!group->owner_cnt || !xa_empty(&group->pasid_array)))
group->owner_cnt--;
mutex_unlock(&group->mutex);
@@ -3185,7 +3188,8 @@ int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner)
ret = -EPERM;
goto unlock_out;
} else {
- if (group->domain && group->domain != group->default_domain) {
+ if ((group->domain && group->domain != group->default_domain) ||
+ !xa_empty(&group->pasid_array)) {
ret = -EBUSY;
goto unlock_out;
}
@@ -3219,7 +3223,8 @@ void iommu_group_release_dma_owner(struct iommu_group *group)
int ret;
mutex_lock(&group->mutex);
- if (WARN_ON(!group->owner_cnt || !group->owner))
+ if (WARN_ON(!group->owner_cnt || !group->owner ||
+ !xa_empty(&group->pasid_array)))
goto unlock_out;
group->owner_cnt = 0;
@@ -3250,3 +3255,131 @@ bool iommu_group_dma_owner_claimed(struct iommu_group *group)
return user;
}
EXPORT_SYMBOL_GPL(iommu_group_dma_owner_claimed);
+
+static int __iommu_set_group_pasid(struct iommu_domain *domain,
+ struct iommu_group *group, ioasid_t pasid)
+{
+ struct group_device *device;
+ int ret = 0;
+
+ list_for_each_entry(device, &group->devices, list) {
+ ret = domain->ops->set_dev_pasid(domain, device->dev, pasid);
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+
+static void __iommu_remove_group_pasid(struct iommu_group *group,
+ ioasid_t pasid)
+{
+ struct group_device *device;
+ const struct iommu_ops *ops;
+
+ list_for_each_entry(device, &group->devices, list) {
+ ops = dev_iommu_ops(device->dev);
+ ops->remove_dev_pasid(device->dev, pasid);
+ }
+}
+
+/*
+ * iommu_attach_device_pasid() - Attach a domain to pasid of device
+ * @domain: the iommu domain.
+ * @dev: the attached device.
+ * @pasid: the pasid of the device.
+ *
+ * Return: 0 on success, or an error.
+ */
+int iommu_attach_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid)
+{
+ struct iommu_group *group;
+ void *curr;
+ int ret;
+
+ if (!domain->ops->set_dev_pasid)
+ return -EOPNOTSUPP;
+
+ group = iommu_group_get(dev);
+ if (!group)
+ return -ENODEV;
+
+ mutex_lock(&group->mutex);
+ curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, domain, GFP_KERNEL);
+ if (curr) {
+ ret = xa_err(curr) ? : -EBUSY;
+ goto out_unlock;
+ }
+
+ ret = __iommu_set_group_pasid(domain, group, pasid);
+ if (ret) {
+ __iommu_remove_group_pasid(group, pasid);
+ xa_erase(&group->pasid_array, pasid);
+ }
+out_unlock:
+ mutex_unlock(&group->mutex);
+ iommu_group_put(group);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_attach_device_pasid);
+
+/*
+ * iommu_detach_device_pasid() - Detach the domain from pasid of device
+ * @domain: the iommu domain.
+ * @dev: the attached device.
+ * @pasid: the pasid of the device.
+ *
+ * The @domain must have been attached to @pasid of the @dev with
+ * iommu_attach_device_pasid().
+ */
+void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev,
+ ioasid_t pasid)
+{
+ struct iommu_group *group = iommu_group_get(dev);
+
+ mutex_lock(&group->mutex);
+ __iommu_remove_group_pasid(group, pasid);
+ WARN_ON(xa_erase(&group->pasid_array, pasid) != domain);
+ mutex_unlock(&group->mutex);
+
+ iommu_group_put(group);
+}
+EXPORT_SYMBOL_GPL(iommu_detach_device_pasid);
+
+/*
+ * iommu_get_domain_for_dev_pasid() - Retrieve domain for @pasid of @dev
+ * @dev: the queried device
+ * @pasid: the pasid of the device
+ * @type: matched domain type, 0 for any match
+ *
+ * This is a variant of iommu_get_domain_for_dev(). It returns the existing
+ * domain attached to pasid of a device. Callers must hold a lock around this
+ * function, and both iommu_attach/detach_dev_pasid() whenever a domain of
+ * type is being manipulated. This API does not internally resolve races with
+ * attach/detach.
+ *
+ * Return: attached domain on success, NULL otherwise.
+ */
+struct iommu_domain *iommu_get_domain_for_dev_pasid(struct device *dev,
+ ioasid_t pasid,
+ unsigned int type)
+{
+ struct iommu_domain *domain;
+ struct iommu_group *group;
+
+ group = iommu_group_get(dev);
+ if (!group)
+ return NULL;
+
+ xa_lock(&group->pasid_array);
+ domain = xa_load(&group->pasid_array, pasid);
+ if (type && domain && domain->type != type)
+ domain = ERR_PTR(-EBUSY);
+ xa_unlock(&group->pasid_array);
+ iommu_group_put(group);
+
+ return domain;
+}
+EXPORT_SYMBOL_GPL(iommu_get_domain_for_dev_pasid);