MIPS: highmem: ensure that we don't use more than one page for PTEs

All PTEs used by PKMAP should be allocated in a contiguous memory area,
but we do not currently have a mechanism to enforce that, so ensure that
we don't try to allocate more entries than would fit in a single page.

Current fixed value of 1024 would not work with XPA enabled when
sizeof(pte_t)==8 and we need two pages to store pte tables.

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15949/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Marcin Nowakowski 2017-04-11 09:00:35 +02:00 committed by Ralf Baechle
parent 71eb989ab5
commit 725a269b3d
1 changed files with 5 additions and 0 deletions

View File

@ -35,7 +35,12 @@ extern pte_t *pkmap_page_table;
* easily, subsequent pte tables have to be allocated in one physical
* chunk of RAM.
*/
#ifdef CONFIG_PHYS_ADDR_T_64BIT
#define LAST_PKMAP 512
#else
#define LAST_PKMAP 1024
#endif
#define LAST_PKMAP_MASK (LAST_PKMAP-1)
#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)
#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))