Re: [PATCH v3 16/34] nios2: Implement the new page table range API

From: Mike Rapoport
Date: Fri Mar 03 2023 - 07:50:34 EST


On Tue, Feb 28, 2023 at 09:37:19PM +0000, Matthew Wilcox (Oracle) wrote:
> Add set_ptes(), update_mmu_cache_range(), flush_icache_pages() and
> flush_dcache_folio(). Change the PG_arch_1 (aka PG_dcache_dirty) flag
> from being per-page to per-folio.

This failed for me with

CC arch/nios2/mm/cacheflush.o
arch/nios2/mm/cacheflush.c: In function 'flush_dcache_folio':
arch/nios2/mm/cacheflush.c:195:48: error: passing argument 2 of 'flush_aliases' from incompatible pointer type [-Werror=incompatible-pointer-types]
195 | flush_aliases(mapping, folio);
| ^~~~~
| |
| struct folio *
arch/nios2/mm/cacheflush.c:74:71: note: expected 'struct page *' but argument is of type 'struct folio *'
74 | static void flush_aliases(struct address_space *mapping, struct page *page)
| ~~~~~~~~~~~~~^~~~
In file included from arch/nios2/mm/cacheflush.c:10:
arch/nios2/mm/cacheflush.c: At top level:
include/linux/export.h:57:43: error: redefinition of '__ksymtab_flush_dcache_folio'
57 | static const struct kernel_symbol __ksymtab_##sym \
| ^~~~~~~~~~
include/linux/export.h:96:9: note: in expansion of macro '__KSYMTAB_ENTRY'
96 | __KSYMTAB_ENTRY(sym, sec)
| ^~~~~~~~~~~~~~~
include/linux/export.h:140:41: note: in expansion of macro '___EXPORT_SYMBOL'
140 | #define __EXPORT_SYMBOL(sym, sec, ns) ___EXPORT_SYMBOL(sym, sec, ns)
| ^~~~~~~~~~~~~~~~
include/linux/export.h:147:41: note: in expansion of macro '__EXPORT_SYMBOL'
147 | #define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, "")
| ^~~~~~~~~~~~~~~
include/linux/export.h:150:41: note: in expansion of macro '_EXPORT_SYMBOL'
150 | #define EXPORT_SYMBOL(sym) _EXPORT_SYMBOL(sym, "")
| ^~~~~~~~~~~~~~
arch/nios2/mm/cacheflush.c:207:1: note: in expansion of macro 'EXPORT_SYMBOL'
207 | EXPORT_SYMBOL(flush_dcache_folio);
| ^~~~~~~~~~~~~
include/linux/export.h:57:43: note: previous definition of '__ksymtab_flush_dcache_folio' with type 'const struct kernel_symbol'
57 | static const struct kernel_symbol __ksymtab_##sym \
| ^~~~~~~~~~
include/linux/export.h:96:9: note: in expansion of macro '__KSYMTAB_ENTRY'
96 | __KSYMTAB_ENTRY(sym, sec)
| ^~~~~~~~~~~~~~~
include/linux/export.h:140:41: note: in expansion of macro '___EXPORT_SYMBOL'
140 | #define __EXPORT_SYMBOL(sym, sec, ns) ___EXPORT_SYMBOL(sym, sec, ns)
| ^~~~~~~~~~~~~~~~
include/linux/export.h:147:41: note: in expansion of macro '__EXPORT_SYMBOL'
147 | #define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, "")
| ^~~~~~~~~~~~~~~
include/linux/export.h:150:41: note: in expansion of macro '_EXPORT_SYMBOL'
150 | #define EXPORT_SYMBOL(sym) _EXPORT_SYMBOL(sym, "")
| ^~~~~~~~~~~~~~
arch/nios2/mm/cacheflush.c:201:1: note: in expansion of macro 'EXPORT_SYMBOL'
201 | EXPORT_SYMBOL(flush_dcache_folio);
| ^~~~~~~~~~~~~
arch/nios2/mm/cacheflush.c: In function 'update_mmu_cache_range':
arch/nios2/mm/cacheflush.c:235:40: error: passing argument 2 of 'flush_aliases' from incompatible pointer type [-Werror=incompatible-pointer-types]
235 | flush_aliases(mapping, folio);
| ^~~~~
| |
| struct folio *
arch/nios2/mm/cacheflush.c:74:71: note: expected 'struct page *' but argument is of type 'struct folio *'
74 | static void flush_aliases(struct address_space *mapping, struct page *page)
| ~~~~~~~~~~~~~^~~~
cc1: some warnings being treated as errors
make[4]: *** [scripts/Makefile.build:252: arch/nios2/mm/cacheflush.o] Error 1
make[3]: *** [scripts/Makefile.build:494: arch/nios2/mm] Error 2
make[2]: *** [scripts/Makefile.build:494: arch/nios2] Error 2
make[1]: *** [Makefile:2028: .] Error 2
make[1]: Leaving directory '/home/mike/build/cross/nios2/defconfig'
make: *** [Makefile:226: __sub-make] Error 2


> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Cc: Dinh Nguyen <dinguyen@xxxxxxxxxx>
> ---
> arch/nios2/include/asm/cacheflush.h | 6 ++-
> arch/nios2/include/asm/pgtable.h | 27 +++++++++----
> arch/nios2/mm/cacheflush.c | 61 ++++++++++++++++-------------
> 3 files changed, 58 insertions(+), 36 deletions(-)
>
> diff --git a/arch/nios2/include/asm/cacheflush.h b/arch/nios2/include/asm/cacheflush.h
> index d0b71dd71287..8624ca83cffe 100644
> --- a/arch/nios2/include/asm/cacheflush.h
> +++ b/arch/nios2/include/asm/cacheflush.h
> @@ -29,9 +29,13 @@ extern void flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
> unsigned long pfn);
> #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
> void flush_dcache_page(struct page *page);
> +void flush_dcache_folio(struct folio *folio);
> +#define flush_dcache_folio flush_dcache_folio
>
> extern void flush_icache_range(unsigned long start, unsigned long end);
> -extern void flush_icache_page(struct vm_area_struct *vma, struct page *page);
> +void flush_icache_pages(struct vm_area_struct *vma, struct page *page,
> + unsigned int nr);
> +#define flush_icache_page(vma, page) flush_icache_pages(vma, page, 1);
>
> #define flush_cache_vmap(start, end) flush_dcache_range(start, end)
> #define flush_cache_vunmap(start, end) flush_dcache_range(start, end)
> diff --git a/arch/nios2/include/asm/pgtable.h b/arch/nios2/include/asm/pgtable.h
> index 0f5c2564e9f5..8a77821a17a5 100644
> --- a/arch/nios2/include/asm/pgtable.h
> +++ b/arch/nios2/include/asm/pgtable.h
> @@ -178,15 +178,23 @@ static inline void set_pte(pte_t *ptep, pte_t pteval)
> *ptep = pteval;
> }
>
> -static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pteval)
> +static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pte, unsigned int nr)
> {
> - unsigned long paddr = (unsigned long)page_to_virt(pte_page(pteval));
> -
> - flush_dcache_range(paddr, paddr + PAGE_SIZE);
> - set_pte(ptep, pteval);
> + unsigned long paddr = (unsigned long)page_to_virt(pte_page(pte));
> +
> + flush_dcache_range(paddr, paddr + nr * PAGE_SIZE);
> + for (;;) {
> + set_pte(ptep, pte);
> + if (--nr == 0)
> + break;
> + ptep++;
> + pte_val(pte) += 1;
> + }
> }
>
> +#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
> +
> static inline int pmd_none(pmd_t pmd)
> {
> return (pmd_val(pmd) ==
> @@ -273,7 +281,10 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte)
> extern void __init paging_init(void);
> extern void __init mmu_init(void);
>
> -extern void update_mmu_cache(struct vm_area_struct *vma,
> - unsigned long address, pte_t *pte);
> +void update_mmu_cache_range(struct vm_area_struct *vma, unsigned long address,
> + pte_t *ptep, unsigned int nr);
> +
> +#define update_mmu_cache(vma, addr, ptep) \
> + update_mmu_cache_range(vma, addr, ptep, 1)
>
> #endif /* _ASM_NIOS2_PGTABLE_H */
> diff --git a/arch/nios2/mm/cacheflush.c b/arch/nios2/mm/cacheflush.c
> index 6aa9257c3ede..471485a84b2c 100644
> --- a/arch/nios2/mm/cacheflush.c
> +++ b/arch/nios2/mm/cacheflush.c
> @@ -138,10 +138,11 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
> __flush_icache(start, end);
> }
>
> -void flush_icache_page(struct vm_area_struct *vma, struct page *page)
> +void flush_icache_pages(struct vm_area_struct *vma, struct page *page,
> + unsigned int nr)
> {
> unsigned long start = (unsigned long) page_address(page);
> - unsigned long end = start + PAGE_SIZE;
> + unsigned long end = start + nr * PAGE_SIZE;
>
> __flush_dcache(start, end);
> __flush_icache(start, end);
> @@ -158,19 +159,19 @@ void flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
> __flush_icache(start, end);
> }
>
> -void __flush_dcache_page(struct address_space *mapping, struct page *page)
> +void __flush_dcache_folio(struct address_space *mapping, struct folio *folio)
> {
> /*
> * Writeback any data associated with the kernel mapping of this
> * page. This ensures that data in the physical page is mutually
> * coherent with the kernels mapping.
> */
> - unsigned long start = (unsigned long)page_address(page);
> + unsigned long start = (unsigned long)folio_address(folio);
>
> - __flush_dcache(start, start + PAGE_SIZE);
> + __flush_dcache(start, start + folio_size(folio));
> }
>
> -void flush_dcache_page(struct page *page)
> +void flush_dcache_folio(struct folio *folio)
> {
> struct address_space *mapping;
>
> @@ -178,32 +179,38 @@ void flush_dcache_page(struct page *page)
> * The zero page is never written to, so never has any dirty
> * cache lines, and therefore never needs to be flushed.
> */
> - if (page == ZERO_PAGE(0))
> + if (is_zero_pfn(folio_pfn(folio)))
> return;
>
> - mapping = page_mapping_file(page);
> + mapping = folio_flush_mapping(folio);
>
> /* Flush this page if there are aliases. */
> if (mapping && !mapping_mapped(mapping)) {
> - clear_bit(PG_dcache_clean, &page->flags);
> + clear_bit(PG_dcache_clean, &folio->flags);
> } else {
> - __flush_dcache_page(mapping, page);
> + __flush_dcache_folio(mapping, folio);
> if (mapping) {
> - unsigned long start = (unsigned long)page_address(page);
> - flush_aliases(mapping, page);
> - flush_icache_range(start, start + PAGE_SIZE);
> + unsigned long start = (unsigned long)folio_address(folio);
> + flush_aliases(mapping, folio);
> + flush_icache_range(start, start + folio_size(folio));
> }
> - set_bit(PG_dcache_clean, &page->flags);
> + set_bit(PG_dcache_clean, &folio->flags);
> }
> }
> -EXPORT_SYMBOL(flush_dcache_page);
> +EXPORT_SYMBOL(flush_dcache_folio);
> +
> +void flush_dcache_page(struct page *page)
> +{
> + flush_dcache_folio(page_folio(page));
> +}
> +EXPORT_SYMBOL(flush_dcache_folio);
>
> -void update_mmu_cache(struct vm_area_struct *vma,
> - unsigned long address, pte_t *ptep)
> +void update_mmu_cache_range(struct vm_area_struct *vma, unsigned long address,
> + pte_t *ptep, unsigned int nr)
> {
> pte_t pte = *ptep;
> unsigned long pfn = pte_pfn(pte);
> - struct page *page;
> + struct folio *folio;
> struct address_space *mapping;
>
> reload_tlb_page(vma, address, pte);
> @@ -215,19 +222,19 @@ void update_mmu_cache(struct vm_area_struct *vma,
> * The zero page is never written to, so never has any dirty
> * cache lines, and therefore never needs to be flushed.
> */
> - page = pfn_to_page(pfn);
> - if (page == ZERO_PAGE(0))
> + if (is_zero_pfn(pfn))
> return;
>
> - mapping = page_mapping_file(page);
> - if (!test_and_set_bit(PG_dcache_clean, &page->flags))
> - __flush_dcache_page(mapping, page);
> + folio = page_folio(pfn_to_page(pfn));
> + mapping = folio_flush_mapping(folio);
> + if (!test_and_set_bit(PG_dcache_clean, &folio->flags))
> + __flush_dcache_folio(mapping, folio);
>
> - if(mapping)
> - {
> - flush_aliases(mapping, page);
> + if (mapping) {
> + flush_aliases(mapping, folio);
> if (vma->vm_flags & VM_EXEC)
> - flush_icache_page(vma, page);
> + flush_icache_pages(vma, &folio->page,
> + folio_nr_pages(folio));
> }
> }
>
> --
> 2.39.1
>
>

--
Sincerely yours,
Mike.