media: atomisp: hmm_bo: Drop PFN code path from alloc_user_pages()

alloc_user_pages() is only ever called on qbuf for USERPTR buffers which
always hits the get_user_pages_fast() path, so the pin_user_pages() path
can be removed.

Getting the vma then also is no longer necessary since that is only
done to determine which path to use.

And this also removes the only users of the mem_type struct hmm_bo member,
so remove that as well.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/staging/media/atomisp/include/hmm/hmm_bo.h

@@ -86,8 +86,6 @@ enum hmm_bo_type {
 #define	HMM_BO_VMAPED		0x10
 #define	HMM_BO_VMAPED_CACHED	0x20
 #define	HMM_BO_ACTIVE		0x1000
-#define	HMM_BO_MEM_TYPE_USER     0x1
-#define	HMM_BO_MEM_TYPE_PFN      0x2
 
 struct hmm_bo_device {
 	struct isp_mmu		mmu;
@@ -123,7 +121,6 @@ struct hmm_buffer_object {
 	enum hmm_bo_type	type;
 	int		mmap_count;
 	int		status;
-	int		mem_type;
 	void		*vmap_addr; /* kernel virtual address by vmap */
 
 	struct rb_node	node;

drivers/staging/media/atomisp/pci/hmm/hmm_bo.c

@@ -656,12 +656,8 @@ static void free_user_pages(struct hmm_buffer_object *bo,
 {
 	int i;
 
-	if (bo->mem_type == HMM_BO_MEM_TYPE_PFN) {
-		unpin_user_pages(bo->pages, page_nr);
-	} else {
-		for (i = 0; i < page_nr; i++)
-			put_page(bo->pages[i]);
-	}
+	for (i = 0; i < page_nr; i++)
+		put_page(bo->pages[i]);
 }
 
 /*
@@ -671,43 +667,13 @@ static int alloc_user_pages(struct hmm_buffer_object *bo,
 			    const void __user *userptr)
 {
 	int page_nr;
-	struct vm_area_struct *vma;
-
-	mutex_unlock(&bo->mutex);
-	mmap_read_lock(current->mm);
-	vma = find_vma(current->mm, (unsigned long)userptr);
-	mmap_read_unlock(current->mm);
-	if (!vma) {
-		dev_err(atomisp_dev, "find_vma failed\n");
-		mutex_lock(&bo->mutex);
-		return -EFAULT;
-	}
-	mutex_lock(&bo->mutex);
-	/*
-	 * Handle frame buffer allocated in other kerenl space driver
-	 * and map to user space
-	 */
 
 	userptr = untagged_addr(userptr);
 
-	if (vma->vm_flags & (VM_IO | VM_PFNMAP)) {
-		page_nr = pin_user_pages((unsigned long)userptr, bo->pgnr,
-					 FOLL_LONGTERM | FOLL_WRITE,
-					 bo->pages, NULL);
-		bo->mem_type = HMM_BO_MEM_TYPE_PFN;
-	} else {
-		/*Handle frame buffer allocated in user space*/
-		mutex_unlock(&bo->mutex);
-		page_nr = get_user_pages_fast((unsigned long)userptr,
-					      (int)(bo->pgnr), 1, bo->pages);
-		mutex_lock(&bo->mutex);
-		bo->mem_type = HMM_BO_MEM_TYPE_USER;
-	}
-
-	dev_dbg(atomisp_dev, "%s: %d %s pages were allocated as 0x%08x\n",
-		__func__,
-		bo->pgnr,
-		bo->mem_type == HMM_BO_MEM_TYPE_USER ? "user" : "pfn", page_nr);
+	/* Handle frame buffer allocated in user space */
+	mutex_unlock(&bo->mutex);
+	page_nr = get_user_pages_fast((unsigned long)userptr, bo->pgnr, 1, bo->pages);
+	mutex_lock(&bo->mutex);
 
 	/* can be written by caller, not forced */
 	if (page_nr != bo->pgnr) {