iommu: Separate SVA and IOPF

Add CONFIG_IOMMU_IOPF for page fault handling framework and select it
from its real consumer. Move iopf function declaration from iommu-sva.h
to iommu.h and remove iommu-sva.h as it's empty now.

Consolidate all SVA related code into iommu-sva.c:
- Move iommu_sva_domain_alloc() from iommu.c to iommu-sva.c.
- Move sva iopf handling code from io-pgfault.c to iommu-sva.c.

Consolidate iommu_report_device_fault() and iommu_page_response() into
io-pgfault.c.

Export iopf_free_group() and iopf_group_response() for iopf handlers
implemented in modules. Some functions are renamed with more meaningful
names. No other intentional functionality changes.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Longfang Liu <liulongfang@huawei.com>
Link: https://lore.kernel.org/r/20240212012227.119381-11-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 60 insertions, 8 deletions

diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index fcae7308fcb7..9de878e40413 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -7,7 +7,7 @@
 #include <linux/sched/mm.h>
 #include <linux/iommu.h>
 
-#include "iommu-sva.h"
+#include "iommu-priv.h"
 
 static DEFINE_MUTEX(iommu_sva_lock);
 
@@ -159,10 +159,21 @@ u32 iommu_sva_get_pasid(struct iommu_sva *handle)
 }
 EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
 
+void mm_pasid_drop(struct mm_struct *mm)
+{
+	struct iommu_mm_data *iommu_mm = mm->iommu_mm;
+
+	if (!iommu_mm)
+		return;
+
+	iommu_free_global_pasid(iommu_mm->pasid);
+	kfree(iommu_mm);
+}
+
 /*
  * I/O page fault handler for SVA
  */
-enum iommu_page_response_code
+static enum iommu_page_response_code
 iommu_sva_handle_mm(struct iommu_fault *fault, struct mm_struct *mm)
 {
 	vm_fault_t ret;
@@ -216,13 +227,54 @@ out_put_mm:
 	return status;
 }
 
-void mm_pasid_drop(struct mm_struct *mm)
+static void iommu_sva_handle_iopf(struct work_struct *work)
 {
-	struct iommu_mm_data *iommu_mm = mm->iommu_mm;
+	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);
+	}
 
-	if (!iommu_mm)
-		return;
+	iopf_group_response(group, status);
+	iopf_free_group(group);
+}
 
-	iommu_free_global_pasid(iommu_mm->pasid);
-	kfree(iommu_mm);
+static int iommu_sva_iopf_handler(struct iopf_group *group)
+{
+	struct iommu_fault_param *fault_param = group->dev->iommu->fault_param;
+
+	INIT_WORK(&group->work, iommu_sva_handle_iopf);
+	if (!queue_work(fault_param->queue->wq, &group->work))
+		return -EBUSY;
+
+	return 0;
+}
+
+struct iommu_domain *iommu_sva_domain_alloc(struct device *dev,
+					    struct mm_struct *mm)
+{
+	const struct iommu_ops *ops = dev_iommu_ops(dev);
+	struct iommu_domain *domain;
+
+	domain = ops->domain_alloc(IOMMU_DOMAIN_SVA);
+	if (!domain)
+		return NULL;
+
+	domain->type = IOMMU_DOMAIN_SVA;
+	mmgrab(mm);
+	domain->mm = mm;
+	domain->owner = ops;
+	domain->iopf_handler = iommu_sva_iopf_handler;
+
+	return domain;
 }