Re: [PATCH 13/7] loongson: Implement the new page table range API

Matthew Wilcox
2023-02-26T04:35:02Z

On Wed, Feb 15, 2023 at 12:04:46AM +0000, Matthew Wilcox (Oracle) wrote:
> Add set_ptes() and update_mmu_cache_range().
>
> THIS PATCH IS INCOMPLETE. I DO NOT KNOW WHAT TO DO IN __update_tlb()

Help? This is the only remaining architecture to fix; I have all the
others converted now.

> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
> arch/loongarch/include/asm/cacheflush.h | 2 ++
> arch/loongarch/include/asm/pgtable.h | 30 ++++++++++++++++---------
> arch/loongarch/mm/tlb.c | 4 +++-
> 3 files changed, 25 insertions(+), 11 deletions(-)
>
> diff --git a/arch/loongarch/include/asm/cacheflush.h b/arch/loongarch/include/asm/cacheflush.h
> index 0681788eb474..7907eb42bfbd 100644
> --- a/arch/loongarch/include/asm/cacheflush.h
> +++ b/arch/loongarch/include/asm/cacheflush.h
> @@ -47,8 +47,10 @@ void local_flush_icache_range(unsigned long start, unsigned long end);
> #define flush_cache_vmap(start, end) do { } while (0)
> #define flush_cache_vunmap(start, end) do { } while (0)
> #define flush_icache_page(vma, page) do { } while (0)
> +#define flush_icache_pages(vma, page) do { } while (0)
> #define flush_icache_user_page(vma, page, addr, len) do { } while (0)
> #define flush_dcache_page(page) do { } while (0)
> +#define flush_dcache_folio(folio) do { } while (0)
> #define flush_dcache_mmap_lock(mapping) do { } while (0)
> #define flush_dcache_mmap_unlock(mapping) do { } while (0)
>
> diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h
> index d28fb9dbec59..0f5fa7c40c52 100644
> --- a/arch/loongarch/include/asm/pgtable.h
> +++ b/arch/loongarch/include/asm/pgtable.h
> @@ -334,12 +334,20 @@ static inline void set_pte(pte_t *ptep, pte_t pteval)
> }
> }
>
> -static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pteval)
> -{
> - set_pte(ptep, pteval);
> +static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pte, unsigned int nr)
> +{
> + for (;;) {
> + set_pte(ptep, pte);
> + if (--nr == 0)
> + break;
> + ptep++;
> + pte_val(pte) += 1 << _PFN_SHIFT;
> + }
> }
>
> +#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
> +
> static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
> {
> /* Preserve global status for the pair */
> @@ -442,14 +450,16 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
> (pgprot_val(newprot) & ~_PAGE_CHG_MASK));
> }
>
> -extern void __update_tlb(struct vm_area_struct *vma,
> - unsigned long address, pte_t *ptep);
> +extern void __update_tlb(struct vm_area_struct *vma, unsigned long address,
> + pte_t *ptep, unsigned int nr);
>
> -static inline void update_mmu_cache(struct vm_area_struct *vma,
> - unsigned long address, pte_t *ptep)
> +static inline void update_mmu_cache_range(struct vm_area_struct *vma,
> + unsigned long address, pte_t *ptep, unsigned int nr)
> {
> - __update_tlb(vma, address, ptep);
> + __update_tlb(vma, address, ptep, nr);
> }
> +#define update_mmu_cache(vma, addr, ptep) \
> + update_mmu_cache_range(vma, addr, ptep, 1)
>
> #define __HAVE_ARCH_UPDATE_MMU_TLB
> #define update_mmu_tlb update_mmu_cache
> @@ -457,7 +467,7 @@ static inline void update_mmu_cache(struct vm_area_struct *vma,
> static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
> unsigned long address, pmd_t *pmdp)
> {
> - __update_tlb(vma, address, (pte_t *)pmdp);
> + __update_tlb(vma, address, (pte_t *)pmdp, 1);
> }
>
> static inline unsigned long pmd_pfn(pmd_t pmd)
> diff --git a/arch/loongarch/mm/tlb.c b/arch/loongarch/mm/tlb.c
> index 8bad6b0cff59..ac0b19dbd1dc 100644
> --- a/arch/loongarch/mm/tlb.c
> +++ b/arch/loongarch/mm/tlb.c
> @@ -162,7 +162,8 @@ static void __update_hugetlb(struct vm_area_struct *vma, unsigned long address,
> #endif
> }
>
> -void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
> +void __update_tlb(struct vm_area_struct *vma, unsigned long address,
> + pte_t *ptep, unsigned int nr)
> {
> int idx;
> unsigned long flags;
> @@ -187,6 +188,7 @@ void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep
> write_csr_entryhi(address);
> tlb_probe();
> idx = read_csr_tlbidx();
> +// I have no idea what to do here
> write_csr_pagesize(PS_DEFAULT_SIZE);
> write_csr_entrylo0(pte_val(*ptep++));
> write_csr_entrylo1(pte_val(*ptep));
> --
> 2.39.1
>