Re: [PATCH 2/2] nds32: fix build failure caused by page table folding updates

[Greentime Hu]

Mike Rapoport <rppt@xxxxxxxxxx> æ 2019å12æ23æ éä äå7:00åéï
>
> From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
>
> The commit 7c2763c42326 ("nds32: use pgtable-nopmd instead of
> 4level-fixup") missed the pmd_off_k() macro which caused the following
> build error:
>
>   CC      arch/nds32/mm/highmem.o
> In file included from arch/nds32/include/asm/page.h:57,
>                  from include/linux/mm_types_task.h:16,
>                  from include/linux/mm_types.h:5,
>                  from include/linux/mmzone.h:21,
>                  from include/linux/gfp.h:6,
>                  from include/linux/xarray.h:14,
>                  from include/linux/radix-tree.h:18,
>                  from include/linux/fs.h:15,
>                  from include/linux/highmem.h:5,
>                  from arch/nds32/mm/highmem.c:5:
> arch/nds32/mm/highmem.c: In function 'kmap_atomic':
> arch/nds32/include/asm/pgtable.h:360:44: error: passing argument 1 of 'pmd_offset' from incompatible pointer type [-Werror=incompatible-pointer-types]
>  #define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
>                                  ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
> arch/nds32/include/asm/memory.h:33:29: note: in definition of macro '__phys_to_virt'
>  #define __phys_to_virt(x) ((x) - PHYS_OFFSET + PAGE_OFFSET)
>                              ^
> arch/nds32/include/asm/pgtable.h:193:55: note: in expansion of macro '__va'
>  #define pmd_page_kernel(pmd)         ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
>                                                        ^~~~
> include/asm-generic/pgtable-nop4d.h:41:24: note: in expansion of macro 'pgd_val'
>  #define p4d_val(x)    (pgd_val((x).pgd))
>                         ^~~~~~~
> include/asm-generic/pgtable-nopud.h:50:24: note: in expansion of macro 'p4d_val'
>  #define pud_val(x)    (p4d_val((x).p4d))
>                         ^~~~~~~
> include/asm-generic/pgtable-nopmd.h:49:24: note: in expansion of macro 'pud_val'
>  #define pmd_val(x)    (pud_val((x).pud))
>                         ^~~~~~~
> arch/nds32/include/asm/pgtable.h:193:60: note: in expansion of macro 'pmd_val'
>  #define pmd_page_kernel(pmd)         ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
>                                                             ^~~~~~~
> arch/nds32/include/asm/pgtable.h:190:56: note: in expansion of macro 'pmd_page_kernel'
>  #define pte_offset_kernel(dir, address)      ((pte_t *)pmd_page_kernel(*(dir)) + pte_index(address))
>                                                         ^~~~~~~~~~~~~~~
> arch/nds32/mm/highmem.c:52:9: note: in expansion of macro 'pte_offset_kernel'
>   ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
>          ^~~~~~~~~~~~~~~~~
> arch/nds32/include/asm/pgtable.h:362:33: note: in expansion of macro 'pgd_offset'
>  #define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
>                                  ^~~~~~~~~~
> arch/nds32/include/asm/pgtable.h:198:39: note: in expansion of macro 'pgd_offset_k'
>  #define pmd_off_k(address) pmd_offset(pgd_offset_k(address), address)
>                                        ^~~~~~~~~~~~
> arch/nds32/mm/highmem.c:52:27: note: in expansion of macro 'pmd_off_k'
>   ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
>                            ^~~~~~~~~
> In file included from arch/nds32/include/asm/pgtable.h:7,
>                  from include/linux/mm.h:99,
>                  from include/linux/highmem.h:8,
>                  from arch/nds32/mm/highmem.c:5:
> include/asm-generic/pgtable-nopmd.h:44:42: note: expected 'pud_t *' {aka 'struct <anonymous> *'} but argument is of type 'pgd_t *' {aka 'long unsigned int *'}
>  static inline pmd_t * pmd_offset(pud_t * pud, unsigned long address)
>                                   ~~~~~~~~^~~
> In file included from arch/nds32/include/asm/page.h:57,
>                  from include/linux/mm_types_task.h:16,
>                  from include/linux/mm_types.h:5,
>                  from include/linux/mmzone.h:21,
>                  from include/linux/gfp.h:6,
>                  from include/linux/xarray.h:14,
>                  from include/linux/radix-tree.h:18,
>                  from include/linux/fs.h:15,
>                  from include/linux/highmem.h:5,
>                  from arch/nds32/mm/highmem.c:5:
>
> Updating the pmd_off_k() macro to use the correct page table unfolding
> fixes the issue.
>
> Fixes: 7c2763c42326 ("nds32: use pgtable-nopmd instead of 4level-fixup")
> Link: https://lore.kernel.org/lkml/201912212139.yptX8CsV%25lkp@xxxxxxxxx/
> Reported-by: kbuild test robot <lkp@xxxxxxxxx>
> Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> ---
>  arch/nds32/include/asm/pgtable.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/nds32/include/asm/pgtable.h b/arch/nds32/include/asm/pgtable.h
> index 0214e4150539..6abc58ac406d 100644
> --- a/arch/nds32/include/asm/pgtable.h
> +++ b/arch/nds32/include/asm/pgtable.h
> @@ -195,7 +195,7 @@ extern void paging_init(void);
>  #define pte_unmap(pte)         do { } while (0)
>  #define pte_unmap_nested(pte)  do { } while (0)
>
> -#define pmd_off_k(address)     pmd_offset(pgd_offset_k(address), address)
> +#define pmd_off_k(address)     pmd_offset(pud_offset(p4d_offset(pgd_offset_k(address), (address)), (address)), (address))
>
>  #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
>  /*

Thank you, Mike.
Reviewed-by: Greentime Hu <green.hu@xxxxxxxxx>