s390/gup: reduce code duplication between [__]get_user_pages_fast functions
Just call __get_user_pages_fast() from get_user_pages_fast() like powerpc.
This saves a lot of duplicated code.
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c
index 5d758db..d3a2b81 100644
--- a/arch/s390/mm/gup.c
+++ b/arch/s390/mm/gup.c
@@ -182,7 +182,13 @@
end = start + len;
if ((end < start) || (end > TASK_SIZE))
return 0;
-
+ /*
+ * local_irq_save() doesn't prevent pagetable teardown, but does
+ * prevent the pagetables from being freed on s390.
+ *
+ * So long as we atomically load page table pointers versus teardown,
+ * we can follow the address down to the the page and take a ref on it.
+ */
local_irq_save(flags);
pgdp = pgd_offset(mm, addr);
do {
@@ -219,63 +225,22 @@
struct page **pages)
{
struct mm_struct *mm = current->mm;
- unsigned long addr, len, end;
- unsigned long next;
- pgd_t *pgdp, pgd;
- int nr = 0;
+ int nr, ret;
start &= PAGE_MASK;
- addr = start;
- len = (unsigned long) nr_pages << PAGE_SHIFT;
- end = start + len;
- if ((end < start) || (end > TASK_SIZE))
- goto slow_irqon;
+ nr = __get_user_pages_fast(start, nr_pages, write, pages);
+ if (nr == nr_pages)
+ return nr;
- /*
- * local_irq_disable() doesn't prevent pagetable teardown, but does
- * prevent the pagetables from being freed on s390.
- *
- * So long as we atomically load page table pointers versus teardown,
- * we can follow the address down to the the page and take a ref on it.
- */
- local_irq_disable();
- pgdp = pgd_offset(mm, addr);
- do {
- pgd = *pgdp;
- barrier();
- next = pgd_addr_end(addr, end);
- if (pgd_none(pgd))
- goto slow;
- if (!gup_pud_range(pgdp, pgd, addr, next, write, pages, &nr))
- goto slow;
- } while (pgdp++, addr = next, addr != end);
- local_irq_enable();
-
- VM_BUG_ON(nr != (end - start) >> PAGE_SHIFT);
- return nr;
-
- {
- int ret;
-slow:
- local_irq_enable();
-slow_irqon:
- /* Try to get the remaining pages with get_user_pages */
- start += nr << PAGE_SHIFT;
- pages += nr;
-
- down_read(&mm->mmap_sem);
- ret = get_user_pages(current, mm, start,
- (end - start) >> PAGE_SHIFT, write, 0, pages, NULL);
- up_read(&mm->mmap_sem);
-
- /* Have to be a bit careful with return values */
- if (nr > 0) {
- if (ret < 0)
- ret = nr;
- else
- ret += nr;
- }
-
- return ret;
- }
+ /* Try to get the remaining pages with get_user_pages */
+ start += nr << PAGE_SHIFT;
+ pages += nr;
+ down_read(&mm->mmap_sem);
+ ret = get_user_pages(current, mm, start,
+ nr_pages - nr, write, 0, pages, NULL);
+ up_read(&mm->mmap_sem);
+ /* Have to be a bit careful with return values */
+ if (nr > 0)
+ ret = (ret < 0) ? nr : ret + nr;
+ return ret;
}