Tweak the I/O page fault handling framework to route the page faults to
the domain and call the page fault handler retrieved from the domain.
This makes the I/O page fault handling framework possible to serve more
usage scenarios as long as they have an IOMMU domain and install a page
fault handler in it. Some unused functions are also removed to avoid
dead code.

Signed-off-by: Lu Baolu <baolu...@linux.intel.com>
---
 drivers/iommu/iommu-sva-lib.h |  1 -
 drivers/iommu/io-pgfault.c    | 69 ++++++-----------------------------
 drivers/iommu/iommu-sva-lib.c | 20 ----------
 3 files changed, 12 insertions(+), 78 deletions(-)

diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h
index 0f33472e5212..90d4bd3a61b1 100644
--- a/drivers/iommu/iommu-sva-lib.h
+++ b/drivers/iommu/iommu-sva-lib.h
@@ -8,7 +8,6 @@
 #include <linux/ioasid.h>
 #include <linux/mm_types.h>
 
-struct mm_struct *iommu_sva_find(ioasid_t pasid);
 struct mm_struct *iommu_sva_domain_mm(struct iommu_domain *domain);
 
 /* I/O Page fault */
diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index 1df8c1dcae77..fc1b2bdeedf8 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -69,62 +69,6 @@ static int iopf_complete_group(struct device *dev, struct 
iopf_fault *iopf,
        return iommu_page_response(dev, &resp);
 }
 
-static enum iommu_page_response_code
-iopf_handle_single(struct iopf_fault *iopf)
-{
-       vm_fault_t ret;
-       struct mm_struct *mm;
-       struct vm_area_struct *vma;
-       unsigned int access_flags = 0;
-       unsigned int fault_flags = FAULT_FLAG_REMOTE;
-       struct iommu_fault_page_request *prm = &iopf->fault.prm;
-       enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID;
-
-       if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID))
-               return status;
-
-       mm = iommu_sva_find(prm->pasid);
-       if (IS_ERR_OR_NULL(mm))
-               return status;
-
-       mmap_read_lock(mm);
-
-       vma = find_extend_vma(mm, prm->addr);
-       if (!vma)
-               /* Unmapped area */
-               goto out_put_mm;
-
-       if (prm->perm & IOMMU_FAULT_PERM_READ)
-               access_flags |= VM_READ;
-
-       if (prm->perm & IOMMU_FAULT_PERM_WRITE) {
-               access_flags |= VM_WRITE;
-               fault_flags |= FAULT_FLAG_WRITE;
-       }
-
-       if (prm->perm & IOMMU_FAULT_PERM_EXEC) {
-               access_flags |= VM_EXEC;
-               fault_flags |= FAULT_FLAG_INSTRUCTION;
-       }
-
-       if (!(prm->perm & IOMMU_FAULT_PERM_PRIV))
-               fault_flags |= FAULT_FLAG_USER;
-
-       if (access_flags & ~vma->vm_flags)
-               /* Access fault */
-               goto out_put_mm;
-
-       ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL);
-       status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID :
-               IOMMU_PAGE_RESP_SUCCESS;
-
-out_put_mm:
-       mmap_read_unlock(mm);
-       mmput(mm);
-
-       return status;
-}
-
 static void iopf_handle_group(struct work_struct *work)
 {
        struct iopf_group *group;
@@ -134,12 +78,23 @@ static void iopf_handle_group(struct work_struct *work)
        group = container_of(work, struct iopf_group, work);
 
        list_for_each_entry_safe(iopf, next, &group->faults, list) {
+               struct iommu_domain *domain;
+
+               domain = iommu_get_domain_for_dev_pasid_async(group->dev,
+                               iopf->fault.prm.pasid);
+               if (!domain || !domain->iopf_handler)
+                       status = IOMMU_PAGE_RESP_INVALID;
+
                /*
                 * 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)
-                       status = iopf_handle_single(iopf);
+                       status = domain->iopf_handler(&iopf->fault,
+                                                     domain->fault_data);
+
+               if (domain)
+                       iommu_domain_put_async(domain);
 
                if (!(iopf->fault.prm.flags &
                      IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE))
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
index 1024c61519dc..d84cffaeb331 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva-lib.c
@@ -69,26 +69,6 @@ static int iommu_sva_alloc_pasid(struct mm_struct *mm,
        return ret;
 }
 
-/* ioasid_find getter() requires a void * argument */
-static bool __mmget_not_zero(void *mm)
-{
-       return mmget_not_zero(mm);
-}
-
-/**
- * iommu_sva_find() - Find mm associated to the given PASID
- * @pasid: Process Address Space ID assigned to the mm
- *
- * On success a reference to the mm is taken, and must be released with 
mmput().
- *
- * Returns the mm corresponding to this PASID, or an error if not found.
- */
-struct mm_struct *iommu_sva_find(ioasid_t pasid)
-{
-       return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero);
-}
-EXPORT_SYMBOL_GPL(iommu_sva_find);
-
 /*
  * Get or put an ioas for a shared memory.
  */
-- 
2.25.1

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