On Tue, Aug 10, 2021 at 05:42:49PM -0700, Vineet Gupta wrote:
> Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxx>
> ---
> arch/arc/include/asm/page.h | 30 ++++++++++++++++--------------
> arch/arc/include/asm/pgalloc.h | 7 ++++++-
> 2 files changed, 22 insertions(+), 15 deletions(-)
>
> diff --git a/arch/arc/include/asm/page.h b/arch/arc/include/asm/page.h
> index c4ac827379cd..313e6f543d2d 100644
> --- a/arch/arc/include/asm/page.h
> +++ b/arch/arc/include/asm/page.h
> @@ -34,6 +34,13 @@ void copy_user_highpage(struct page *to, struct page *from,
> unsigned long u_vaddr, struct vm_area_struct *vma);
> void clear_user_page(void *to, unsigned long u_vaddr, struct page *page);
>
> +typedef struct {
> + unsigned long pgd;
> +} pgd_t;
> +
> +#define pgd_val(x) ((x).pgd)
> +#define __pgd(x) ((pgd_t) { (x) })
> +
> typedef struct {
> #ifdef CONFIG_ARC_HAS_PAE40
> unsigned long long pte;
> @@ -41,22 +48,17 @@ typedef struct {
> unsigned long pte;
> #endif
> } pte_t;
> -typedef struct {
> - unsigned long pgd;
> -} pgd_t;
> +
> +#define pte_val(x) ((x).pte)
> +#define __pte(x) ((pte_t) { (x) })
> +
> typedef struct {
> unsigned long pgprot;
> } pgprot_t;
>
> -#define pte_val(x) ((x).pte)
> -#define pgd_val(x) ((x).pgd)
> -#define pgprot_val(x) ((x).pgprot)
> -
> -#define __pte(x) ((pte_t) { (x) })
> -#define __pgd(x) ((pgd_t) { (x) })
> -#define __pgprot(x) ((pgprot_t) { (x) })
> -
> -#define pte_pgprot(x) __pgprot(pte_val(x))
> +#define pgprot_val(x) ((x).pgprot)
> +#define __pgprot(x) ((pgprot_t) { (x) })
> +#define pte_pgprot(x) __pgprot(pte_val(x))
>
> typedef pte_t * pgtable_t;
>
> @@ -96,8 +98,8 @@ extern int pfn_valid(unsigned long pfn);
> * virt here means link-address/program-address as embedded in object code.
> * And for ARC, link-addr = physical address
> */
> -#define __pa(vaddr) ((unsigned long)(vaddr))
> -#define __va(paddr) ((void *)((unsigned long)(paddr)))
> +#define __pa(vaddr) ((unsigned long)(vaddr))
> +#define __va(paddr) ((void *)((unsigned long)(paddr)))
>
> #define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr))
> #define virt_addr_valid(kaddr) pfn_valid(virt_to_pfn(kaddr))
> diff --git a/arch/arc/include/asm/pgalloc.h b/arch/arc/include/asm/pgalloc.h
> index 356237b9c537..0cf73431eb89 100644
> --- a/arch/arc/include/asm/pgalloc.h
> +++ b/arch/arc/include/asm/pgalloc.h
> @@ -29,6 +29,11 @@
> #ifndef _ASM_ARC_PGALLOC_H
> #define _ASM_ARC_PGALLOC_H
>
> +/*
> + * For ARC, pgtable_t is not struct page *, but pte_t * (to avoid
> + * extraneous page_address() calculations) hence can't use
> + * use asm-generic/pgalloc.h which assumes it being struct page *
> + */
Another reason to leave ARC without asm-generic/pgalloc.h was
__get_order_pte() that other arches don't have.
So this and pgtable_t aliased to pte_t * seemed to me too much to bother
then, but probably it's worth reconsidering with addition of 3rd and 4th
levels.
> #include <linux/mm.h>
> #include <linux/log2.h>
>
> @@ -36,7 +41,7 @@ static inline void
> pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
> {
> /*
> - * The cast to long below is OK even when pte is long long (PAE40)
> + * The cast to long below is OK in 32-bit PAE40 regime with long long pte
> * Despite "wider" pte, the pte table needs to be in non-PAE low memory
> * as all higher levels can only hold long pointers.
> *
> --
> 2.25.1
>
--
Sincerely yours,
Mike.
