[PATCH v5 6/7] iommu/vt-d: Implement set_dev_pasid domain op

Jacob Pan
2023-04-27T17:46:11Z

Devices that use ENQCMDS to submit work on buffers mapped by DMA API
must attach a PASID to the default domain of the device. In preparation
for this use case, this patch implements set_dev_pasid() for the
default_domain_ops.

If the device context has not been set up prior to this call, this will
set up the device context in addition to PASID attachment.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
drivers/iommu/intel/iommu.c | 92 ++++++++++++++++++++++++++++++-------
1 file changed, 76 insertions(+), 16 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 388453a7415e..f9d6c31cdc8e 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -278,6 +278,8 @@ static LIST_HEAD(dmar_satc_units);
list_for_each_entry(rmrr, &dmar_rmrr_units, list)

static void device_block_translation(struct device *dev);
+static void intel_iommu_detach_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid);
static void intel_iommu_domain_free(struct iommu_domain *domain);

int dmar_disabled = !IS_ENABLED(CONFIG_INTEL_IOMMU_DEFAULT_ON);
@@ -4091,8 +4093,7 @@ static void device_block_translation(struct device *dev)
iommu_disable_pci_caps(info);
if (!dev_is_real_dma_subdevice(dev)) {
if (sm_supported(iommu))
- intel_pasid_tear_down_entry(iommu, dev,
- IOMMU_DEF_RID_PASID, false);
+ intel_iommu_detach_device_pasid(&info->domain->domain, dev, IOMMU_DEF_RID_PASID);
else
domain_context_clear(info);
}
@@ -4761,28 +4762,86 @@ static void intel_iommu_iotlb_sync_map(struct iommu_domain *domain,
__mapping_notify_one(info->iommu, dmar_domain, pfn, pages);
}

-static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
+static void intel_iommu_detach_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid)
{
- struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
- struct iommu_domain *domain;
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+ struct device_pasid_info *i, *dev_pasid = NULL;
+ struct intel_iommu *iommu = info->iommu;
+ unsigned long flags;

- /* Domain type specific cleanup: */
- domain = iommu_get_domain_for_dev_pasid(dev, pasid, 0);
- if (domain) {
- switch (domain->type) {
- case IOMMU_DOMAIN_SVA:
- intel_svm_remove_dev_pasid(dev, pasid);
- break;
- default:
- /* should never reach here */
- WARN_ON(1);
+ spin_lock_irqsave(&dmar_domain->lock, flags);
+ list_for_each_entry(i, &dmar_domain->dev_pasids, link_domain) {
+ if (i->dev == dev && i->pasid == pasid) {
+ list_del(&i->link_domain);
+ dev_pasid = i;
break;
}
}
+ spin_unlock_irqrestore(&dmar_domain->lock, flags);
+ if (WARN_ON(!dev_pasid))
+ return;
+
+ /* PASID entry already cleared during SVA unbind */
+ if (domain->type != IOMMU_DOMAIN_SVA)
+ intel_pasid_tear_down_entry(iommu, dev, pasid, false);
+
+ kfree(dev_pasid);
+}
+
+static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
+{
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct dmar_domain *dmar_domain;
+ struct iommu_domain *domain;
+
+ domain = iommu_get_domain_for_dev_pasid(dev, pasid, 0);
+ dmar_domain = to_dmar_domain(domain);
+
+ /*
+ * SVA Domain type specific cleanup: Not ideal but not until we have
+ * IOPF capable domain specific ops, we need this special case.
+ */
+ if (domain->type == IOMMU_DOMAIN_SVA)
+ return intel_svm_remove_dev_pasid(dev, pasid);

- intel_pasid_tear_down_entry(iommu, dev, pasid, false);
+ intel_iommu_detach_device_pasid(domain, dev, pasid);
+ domain_detach_iommu(dmar_domain, info->iommu);
}

+static int intel_iommu_attach_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid)
+{
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+ struct intel_iommu *iommu = info->iommu;
+ int ret;
+
+ if (!pasid_supported(iommu))
+ return -ENODEV;
+
+ ret = prepare_domain_attach_device(domain, dev);
+ if (ret)
+ return ret;
+
+ /*
+ * Most likely the device context has already been set up, will only
+ * take a domain ID reference. Otherwise, device context will be set
+ * up here.
+ * The upper layer APIs make no assumption about the ordering between
+ * device attachment and the PASID attachment.
+ */
+ ret = dmar_domain_attach_device(to_dmar_domain(domain), dev);
+ if (ret) {
+ dev_err(dev, "Attach device failed\n");
+ return ret;
+ }
+ return dmar_domain_attach_device_pasid(dmar_domain, iommu, dev, pasid);
+}
+
+
+
const struct iommu_ops intel_iommu_ops = {
.capable = intel_iommu_capable,
.domain_alloc = intel_iommu_domain_alloc,
@@ -4802,6 +4861,7 @@ const struct iommu_ops intel_iommu_ops = {
#endif
.default_domain_ops = &(const struct iommu_domain_ops) {
.attach_dev = intel_iommu_attach_device,
+ .set_dev_pasid = intel_iommu_attach_device_pasid,
.map_pages = intel_iommu_map_pages,
.unmap_pages = intel_iommu_unmap_pages,
.iotlb_sync_map = intel_iommu_iotlb_sync_map,
--
2.25.1