IB/hfi1: Assign npages earlier

Improve code clarity and enable earlier use of
tidbuf->npages by moving its assignment to
structure creation time.
Signed-off-by: Dean Luick <dean.luick@cornelisnetworks.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Link: https://lore.kernel.org/r/167329104884.1472990.4639750192433251493.stgit@awfm-02.cornelisnetworks.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/hw/hfi1/user_exp_rcv.c

@@ -152,16 +152,11 @@ static void unpin_rcv_pages(struct hfi1_filedata *fd,
 static int pin_rcv_pages(struct hfi1_filedata *fd, struct tid_user_buf *tidbuf)
 {
 	int pinned;
-	unsigned int npages;
+	unsigned int npages = tidbuf->npages;
 	unsigned long vaddr = tidbuf->vaddr;
 	struct page **pages = NULL;
 	struct hfi1_devdata *dd = fd->uctxt->dd;
 
-	/* Get the number of pages the user buffer spans */
-	npages = num_user_pages(vaddr, tidbuf->length);
-	if (!npages)
-		return -EINVAL;
-
 	if (npages > fd->uctxt->expected_count) {
 		dd_dev_err(dd, "Expected buffer too big\n");
 		return -EINVAL;
@@ -188,7 +183,6 @@ static int pin_rcv_pages(struct hfi1_filedata *fd, struct tid_user_buf *tidbuf)
 		return pinned;
 	}
 	tidbuf->pages = pages;
-	tidbuf->npages = npages;
 	fd->tid_n_pinned += pinned;
 	return pinned;
 }
@@ -262,6 +256,7 @@ int hfi1_user_exp_rcv_setup(struct hfi1_filedata *fd,
 
 	tidbuf->vaddr = tinfo->vaddr;
 	tidbuf->length = tinfo->length;
+	tidbuf->npages = num_user_pages(tidbuf->vaddr, tidbuf->length);
 	tidbuf->psets = kcalloc(uctxt->expected_count, sizeof(*tidbuf->psets),
 				GFP_KERNEL);
 	if (!tidbuf->psets) {