Redefined nents_last, which means # of gref in the last page of lvl2 table in any situation even if it is same as REFS_PER_PAGE. With this, loop can be simplified with less condition check.
Signed-off-by: Dongwon Kim dongwon.kim@intel.com --- drivers/xen/hyper_dmabuf/xen/hyper_dmabuf_xen_shm.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/xen/hyper_dmabuf/xen/hyper_dmabuf_xen_shm.c b/drivers/xen/hyper_dmabuf/xen/hyper_dmabuf_xen_shm.c index cc9860b..cb5b86f 100644 --- a/drivers/xen/hyper_dmabuf/xen/hyper_dmabuf_xen_shm.c +++ b/drivers/xen/hyper_dmabuf/xen/hyper_dmabuf_xen_shm.c @@ -184,8 +184,10 @@ struct page ** hyper_dmabuf_xen_map_shared_pages(int lvl3_gref, int domid, int n struct gnttab_map_grant_ref *data_map_ops; struct gnttab_unmap_grant_ref *data_unmap_ops;
- int nents_last = nents % REFS_PER_PAGE; - int n_lvl2_grefs = (nents / REFS_PER_PAGE) + ((nents_last > 0) ? 1 : 0); + /* # of grefs in the last page of lvl2 table */ + int nents_last = (nents - 1) % REFS_PER_PAGE + 1; + int n_lvl2_grefs = (nents / REFS_PER_PAGE) + ((nents_last > 0) ? 1 : 0) - + (nents_last == REFS_PER_PAGE); int i, j, k;
dev_dbg(hyper_dmabuf_private.device, "%s entry\n", __func__); @@ -270,7 +272,7 @@ struct page ** hyper_dmabuf_xen_map_shared_pages(int lvl3_gref, int domid, int n
k = 0;
- for (i = 0; i < (nents_last ? n_lvl2_grefs - 1 : n_lvl2_grefs); i++) { + for (i = 0; i < n_lvl2_grefs - 1; i++) { lvl2_table = pfn_to_kaddr(page_to_pfn(lvl2_table_pages[i])); for (j = 0; j < REFS_PER_PAGE; j++) { gnttab_set_map_op(&data_map_ops[k],