drm/omap: fix tiled buffer stride calculations

[ Upstream commit cc8dd7661ccc2d8dc88921da8e6cc7c2fcdb0341 ]

omap_gem uses page alignment for buffer stride. The related calculations
are a bit off, though, as byte stride of 4096 gets aligned to 8192,
instead of 4096.

This patch changes the code to use DIV_ROUND_UP(), which fixes those
calculations and makes them more readable.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c
index 505dee0..ca91651 100644 (file)
--- a/drivers/gpu/drm/omapdrm/omap_gem.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem.c
@@ -195,7 +195,7 @@ static void evict_entry(struct drm_gem_object *obj,
        size_t size = PAGE_SIZE * n;
        loff_t off = mmap_offset(obj) +
                        (entry->obj_pgoff << PAGE_SHIFT);
-       const int m = 1 + ((omap_obj->width << fmt) / PAGE_SIZE);
+       const int m = DIV_ROUND_UP(omap_obj->width << fmt, PAGE_SIZE);
 
        if (m > 1) {
                int i;
@@ -442,7 +442,7 @@ static int fault_2d(struct drm_gem_object *obj,
         * into account in some of the math, so figure out virtual stride
         * in pages
         */
-       const int m = 1 + ((omap_obj->width << fmt) / PAGE_SIZE);
+       const int m = DIV_ROUND_UP(omap_obj->width << fmt, PAGE_SIZE);
 
        /* We don't use vmf->pgoff since that has the fake offset: */
        pgoff = ((unsigned long)vmf->virtual_address -