Re: [PATCH v4 05/13] m68k: mm: use pgtable-nopXd instead of 4level-fixup

Geert Uytterhoeven
2019-11-08T08:35:44Z

Hi Mike,

On Tue, Nov 5, 2019 at 8:16 AM Mike Rapoport <rppt@kernel.org> wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
>
> m68k has two or three levels of page tables and can use appropriate
> pgtable-nopXd and folding of the upper layers.
>
> Replace usage of include/asm-generic/4level-fixup.h and explicit
> definitions of __PAGETABLE_PxD_FOLDED in m68k with
> include/asm-generic/pgtable-nopmd.h for two-level configurations and with
> include/asm-generic/pgtable-nopud.h for three-lelve configurations and
> adjust page table manipulation macros and functions accordingly.
>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> Acked-by: Greg Ungerer <gerg@linux-m68k.org>

Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

One forgotten error message update below.

> --- a/arch/m68k/mm/kmap.c
> +++ b/arch/m68k/mm/kmap.c
> @@ -258,18 +265,23 @@ void __iounmap(void *addr, unsigned long size)
> {
> unsigned long virtaddr = (unsigned long)addr;
> pgd_t *pgd_dir;
> + p4d_t *p4d_dir;
> + pud_t *pud_dir;
> pmd_t *pmd_dir;
> pte_t *pte_dir;
>
> while ((long)size > 0) {
> pgd_dir = pgd_offset_k(virtaddr);
> - if (pgd_bad(*pgd_dir)) {
> - printk("iounmap: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
> - pgd_clear(pgd_dir);
> + p4d_dir = p4d_offset(pgd_dir, virtaddr);
> + pud_dir = pud_offset(p4d_dir, virtaddr);
> + if (pud_bad(*pud_dir)) {
> + printk("iounmap: bad pgd(%08lx)\n", pud_val(*pud_dir));

bad pud

> + pud_clear(pud_dir);
> return;
> }
> - pmd_dir = pmd_offset(pgd_dir, virtaddr);
> + pmd_dir = pmd_offset(pud_dir, virtaddr);
>
> +#if CONFIG_PGTABLE_LEVELS == 3
> if (CPU_IS_020_OR_030) {
> int pmd_off = (virtaddr/PTRTREESIZE) & 15;
> int pmd_type = pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK;

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds