+void gnttab_foreach_grant_in_range(struct page *page,
+ unsigned int offset,
+ unsigned int len,
+ xen_grant_fn_t fn,
+ void *data)
+{
+ unsigned int goffset;
+ unsigned int glen;
+ unsigned long xen_pfn;
+
+ len = min_t(unsigned int, PAGE_SIZE - offset, len);
+ goffset = xen_offset_in_page(offset);
+
+ xen_pfn = page_to_xen_pfn(page) + XEN_PFN_DOWN(offset);
+
+ while (len) {
+ glen = min_t(unsigned int, XEN_PAGE_SIZE - goffset, len);
+ fn(pfn_to_gfn(xen_pfn), goffset, glen, data);
+
+ goffset = 0;
+ xen_pfn++;
+ len -= glen;
+ }
+}
+EXPORT_SYMBOL_GPL(gnttab_foreach_grant_in_range);
+
+void gnttab_foreach_grant(struct page **pages,
+ unsigned int nr_grefs,
+ xen_grant_fn_t fn,
+ void *data)
+{
+ unsigned int goffset = 0;
+ unsigned long xen_pfn = 0;
+ unsigned int i;
+
+ for (i = 0; i < nr_grefs; i++) {
+ if ((i % XEN_PFN_PER_PAGE) == 0) {
+ xen_pfn = page_to_xen_pfn(pages[i / XEN_PFN_PER_PAGE]);
+ goffset = 0;
+ }
+
+ fn(pfn_to_gfn(xen_pfn), goffset, XEN_PAGE_SIZE, data);
+
+ goffset += XEN_PAGE_SIZE;
+ xen_pfn++;
+ }
+}
+