1 files changed, 136 insertions, 52 deletions

diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index 13cd0929e766..c1e88da973ce 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -11,12 +11,9 @@
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 
-#include "iommu-sva.h"
+#include "iommu-priv.h"
 
-enum iommu_page_response_code
-iommu_sva_handle_mm(struct iommu_fault *fault, struct mm_struct *mm);
-
-static void iopf_free_group(struct iopf_group *group)
+void iopf_free_group(struct iopf_group *group)
 {
 	struct iopf_fault *iopf, *next;
 
@@ -27,44 +24,7 @@ static void iopf_free_group(struct iopf_group *group)
 
 	kfree(group);
 }
-
-static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf,
-			       enum iommu_page_response_code status)
-{
-	struct iommu_page_response resp = {
-		.pasid			= iopf->fault.prm.pasid,
-		.grpid			= iopf->fault.prm.grpid,
-		.code			= status,
-	};
-
-	if ((iopf->fault.prm.flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID) &&
-	    (iopf->fault.prm.flags & IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID))
-		resp.flags = IOMMU_PAGE_RESP_PASID_VALID;
-
-	return iommu_page_response(dev, &resp);
-}
-
-static void iopf_handler(struct work_struct *work)
-{
-	struct iopf_fault *iopf;
-	struct iopf_group *group;
-	enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS;
-
-	group = container_of(work, struct iopf_group, work);
-	list_for_each_entry(iopf, &group->faults, list) {
-		/*
-		 * For the moment, errors are sticky: don't handle subsequent
-		 * faults in the group if there is an error.
-		 */
-		if (status != IOMMU_PAGE_RESP_SUCCESS)
-			break;
-
-		status = iommu_sva_handle_mm(&iopf->fault, group->domain->mm);
-	}
-
-	iopf_complete_group(group->dev, &group->last_fault, status);
-	iopf_free_group(group);
-}
+EXPORT_SYMBOL_GPL(iopf_free_group);
 
 static struct iommu_domain *get_domain_for_iopf(struct device *dev,
 						struct iommu_fault *fault)
@@ -91,7 +51,7 @@ static struct iommu_domain *get_domain_for_iopf(struct device *dev,
 }
 
 /**
- * iommu_queue_iopf - IO Page Fault handler
+ * iommu_handle_iopf - IO Page Fault handler
  * @fault: fault event
  * @dev: struct device.
  *
@@ -130,7 +90,7 @@ static struct iommu_domain *get_domain_for_iopf(struct device *dev,
  *
  * Return: 0 on success and <0 on error.
  */
-int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
+static int iommu_handle_iopf(struct iommu_fault *fault, struct device *dev)
 {
 	int ret;
 	struct iopf_group *group;
@@ -212,18 +172,117 @@ cleanup_partial:
 	}
 	return ret;
 }
-EXPORT_SYMBOL_GPL(iommu_queue_iopf);
 
-int iommu_sva_handle_iopf(struct iopf_group *group)
+/**
+ * iommu_report_device_fault() - Report fault event to device driver
+ * @dev: the device
+ * @evt: fault event data
+ *
+ * Called by IOMMU drivers when a fault is detected, typically in a threaded IRQ
+ * handler. When this function fails and the fault is recoverable, it is the
+ * caller's responsibility to complete the fault.
+ *
+ * Return 0 on success, or an error.
+ */
+int iommu_report_device_fault(struct device *dev, struct iopf_fault *evt)
 {
-	struct iommu_fault_param *fault_param = group->dev->iommu->fault_param;
+	struct dev_iommu *param = dev->iommu;
+	struct iopf_fault *evt_pending = NULL;
+	struct iommu_fault_param *fparam;
+	int ret = 0;
 
-	INIT_WORK(&group->work, iopf_handler);
-	if (!queue_work(fault_param->queue->wq, &group->work))
-		return -EBUSY;
+	if (!param || !evt)
+		return -EINVAL;
 
-	return 0;
+	/* we only report device fault if there is a handler registered */
+	mutex_lock(&param->lock);
+	fparam = param->fault_param;
+
+	if (evt->fault.type == IOMMU_FAULT_PAGE_REQ &&
+	    (evt->fault.prm.flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE)) {
+		evt_pending = kmemdup(evt, sizeof(struct iopf_fault),
+				      GFP_KERNEL);
+		if (!evt_pending) {
+			ret = -ENOMEM;
+			goto done_unlock;
+		}
+		mutex_lock(&fparam->lock);
+		list_add_tail(&evt_pending->list, &fparam->faults);
+		mutex_unlock(&fparam->lock);
+	}
+
+	ret = iommu_handle_iopf(&evt->fault, dev);
+	if (ret && evt_pending) {
+		mutex_lock(&fparam->lock);
+		list_del(&evt_pending->list);
+		mutex_unlock(&fparam->lock);
+		kfree(evt_pending);
+	}
+done_unlock:
+	mutex_unlock(&param->lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_report_device_fault);
+
+int iommu_page_response(struct device *dev,
+			struct iommu_page_response *msg)
+{
+	bool needs_pasid;
+	int ret = -EINVAL;
+	struct iopf_fault *evt;
+	struct iommu_fault_page_request *prm;
+	struct dev_iommu *param = dev->iommu;
+	const struct iommu_ops *ops = dev_iommu_ops(dev);
+	bool has_pasid = msg->flags & IOMMU_PAGE_RESP_PASID_VALID;
+
+	if (!ops->page_response)
+		return -ENODEV;
+
+	if (!param || !param->fault_param)
+		return -EINVAL;
+
+	/* Only send response if there is a fault report pending */
+	mutex_lock(&param->fault_param->lock);
+	if (list_empty(&param->fault_param->faults)) {
+		dev_warn_ratelimited(dev, "no pending PRQ, drop response\n");
+		goto done_unlock;
+	}
+	/*
+	 * Check if we have a matching page request pending to respond,
+	 * otherwise return -EINVAL
+	 */
+	list_for_each_entry(evt, &param->fault_param->faults, list) {
+		prm = &evt->fault.prm;
+		if (prm->grpid != msg->grpid)
+			continue;
+
+		/*
+		 * If the PASID is required, the corresponding request is
+		 * matched using the group ID, the PASID valid bit and the PASID
+		 * value. Otherwise only the group ID matches request and
+		 * response.
+		 */
+		needs_pasid = prm->flags & IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID;
+		if (needs_pasid && (!has_pasid || msg->pasid != prm->pasid))
+			continue;
+
+		if (!needs_pasid && has_pasid) {
+			/* No big deal, just clear it. */
+			msg->flags &= ~IOMMU_PAGE_RESP_PASID_VALID;
+			msg->pasid = 0;
+		}
+
+		ret = ops->page_response(dev, evt, msg);
+		list_del(&evt->list);
+		kfree(evt);
+		break;
+	}
+
+done_unlock:
+	mutex_unlock(&param->fault_param->lock);
+	return ret;
 }
+EXPORT_SYMBOL_GPL(iommu_page_response);
 
 /**
  * iopf_queue_flush_dev - Ensure that all queued faults have been processed
@@ -259,6 +318,31 @@ int iopf_queue_flush_dev(struct device *dev)
 EXPORT_SYMBOL_GPL(iopf_queue_flush_dev);
 
 /**
+ * iopf_group_response - Respond a group of page faults
+ * @group: the group of faults with the same group id
+ * @status: the response code
+ *
+ * Return 0 on success and <0 on error.
+ */
+int iopf_group_response(struct iopf_group *group,
+			enum iommu_page_response_code status)
+{
+	struct iopf_fault *iopf = &group->last_fault;
+	struct iommu_page_response resp = {
+		.pasid = iopf->fault.prm.pasid,
+		.grpid = iopf->fault.prm.grpid,
+		.code = status,
+	};
+
+	if ((iopf->fault.prm.flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID) &&
+	    (iopf->fault.prm.flags & IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID))
+		resp.flags = IOMMU_PAGE_RESP_PASID_VALID;
+
+	return iommu_page_response(group->dev, &resp);
+}
+EXPORT_SYMBOL_GPL(iopf_group_response);
+
+/**
  * iopf_queue_discard_partial - Remove all pending partial fault
  * @queue: the queue whose partial faults need to be discarded
  *