Re: [PATCH v4 18/36] openrisc: Implement the new page table range API

[Mike Rapoport]

On Wed, Mar 15, 2023 at 05:14:26AM +0000, Matthew Wilcox (Oracle) wrote:
> Add PFN_PTE_SHIFT, update_mmu_cache_range() and flush_dcache_folio().
> Change the PG_arch_1 (aka PG_dcache_dirty) flag from being per-page
> to per-folio.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Cc: Jonas Bonn <jonas@xxxxxxxxxxxx>
> Cc: Stefan Kristiansson <stefan.kristiansson@xxxxxxxxxxxxx>
> Cc: Stafford Horne <shorne@xxxxxxxxx>
> Cc: linux-openrisc@xxxxxxxxxxxxxxx

Acked-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>

> ---
>  arch/openrisc/include/asm/cacheflush.h |  8 +++++++-
>  arch/openrisc/include/asm/pgtable.h    | 14 +++++++++-----
>  arch/openrisc/mm/cache.c               | 12 ++++++++----
>  3 files changed, 24 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/openrisc/include/asm/cacheflush.h b/arch/openrisc/include/asm/cacheflush.h
> index eeac40d4a854..984c331ff5f4 100644
> --- a/arch/openrisc/include/asm/cacheflush.h
> +++ b/arch/openrisc/include/asm/cacheflush.h
> @@ -56,10 +56,16 @@ static inline void sync_icache_dcache(struct page *page)
>   */
>  #define PG_dc_clean                  PG_arch_1
>  
> +static inline void flush_dcache_folio(struct folio *folio)
> +{
> +	clear_bit(PG_dc_clean, &folio->flags);
> +}
> +#define flush_dcache_folio flush_dcache_folio
> +
>  #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
>  static inline void flush_dcache_page(struct page *page)
>  {
> -	clear_bit(PG_dc_clean, &page->flags);
> +	flush_dcache_folio(page_folio(page));
>  }
>  
>  #define flush_icache_user_page(vma, page, addr, len)	\
> diff --git a/arch/openrisc/include/asm/pgtable.h b/arch/openrisc/include/asm/pgtable.h
> index 3eb9b9555d0d..2f42a12c40ab 100644
> --- a/arch/openrisc/include/asm/pgtable.h
> +++ b/arch/openrisc/include/asm/pgtable.h
> @@ -46,7 +46,7 @@ extern void paging_init(void);
>   * hook is made available.
>   */
>  #define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval))
> -#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
> +
>  /*
>   * (pmds are folded into pgds so this doesn't get actually called,
>   * but the define is needed for a generic inline function.)
> @@ -357,6 +357,7 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd)
>  #define __pmd_offset(address) \
>  	(((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
>  
> +#define PFN_PTE_SHIFT		PAGE_SHIFT
>  #define pte_pfn(x)		((unsigned long)(((x).pte)) >> PAGE_SHIFT)
>  #define pfn_pte(pfn, prot)  __pte((((pfn) << PAGE_SHIFT)) | pgprot_val(prot))
>  
> @@ -379,13 +380,16 @@ static inline void update_tlb(struct vm_area_struct *vma,
>  extern void update_cache(struct vm_area_struct *vma,
>  	unsigned long address, pte_t *pte);
>  
> -static inline void update_mmu_cache(struct vm_area_struct *vma,
> -	unsigned long address, pte_t *pte)
> +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, pte);
> -	update_cache(vma, address, pte);
> +	update_tlb(vma, address, ptep);
> +	update_cache(vma, address, ptep);
>  }
>  
> +#define update_mmu_cache(vma, addr, ptep) \
> +	update_mmu_cache_range(vma, addr, ptep, 1)
> +
>  /* __PHX__ FIXME, SWAP, this probably doesn't work */
>  
>  /*
> diff --git a/arch/openrisc/mm/cache.c b/arch/openrisc/mm/cache.c
> index 534a52ec5e66..eb43b73f3855 100644
> --- a/arch/openrisc/mm/cache.c
> +++ b/arch/openrisc/mm/cache.c
> @@ -43,15 +43,19 @@ void update_cache(struct vm_area_struct *vma, unsigned long address,
>  	pte_t *pte)
>  {
>  	unsigned long pfn = pte_val(*pte) >> PAGE_SHIFT;
> -	struct page *page = pfn_to_page(pfn);
> -	int dirty = !test_and_set_bit(PG_dc_clean, &page->flags);
> +	struct folio *folio = page_folio(pfn_to_page(pfn));
> +	int dirty = !test_and_set_bit(PG_dc_clean, &folio->flags);
>  
>  	/*
>  	 * Since icaches do not snoop for updated data on OpenRISC, we
>  	 * must write back and invalidate any dirty pages manually. We
>  	 * can skip data pages, since they will not end up in icaches.
>  	 */
> -	if ((vma->vm_flags & VM_EXEC) && dirty)
> -		sync_icache_dcache(page);
> +	if ((vma->vm_flags & VM_EXEC) && dirty) {
> +		unsigned int nr = folio_nr_pages(folio);
> +
> +		while (nr--)
> +			sync_icache_dcache(folio_page(folio, nr));
> +	}
>  }
>  
> -- 
> 2.39.2
> 
> 

-- 
Sincerely yours,
Mike.