Re: [PATCH v4 23/36] superh: Implement the new page table range API

From: John Paul Adrian Glaubitz
Date: Wed Mar 15 2023 - 03:38:59 EST


Hi Matthew!

On Wed, 2023-03-15 at 05:14 +0000, Matthew Wilcox (Oracle) wrote:
> Add PFN_PTE_SHIFT, update_mmu_cache_range(), flush_dcache_folio() and
> flush_icache_pages(). Change the PG_dcache_clean flag from being
> per-page to per-folio. Flush the entire folio containing the pages in
> flush_icache_pages() for ease of implementation.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
> Cc: Rich Felker <dalias@xxxxxxxx>
> Cc: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
> Cc: linux-sh@xxxxxxxxxxxxxxx
> ---
> arch/sh/include/asm/cacheflush.h | 21 ++++++++-----
> arch/sh/include/asm/pgtable.h | 6 ++--
> arch/sh/include/asm/pgtable_32.h | 5 ++-
> arch/sh/mm/cache-j2.c | 4 +--
> arch/sh/mm/cache-sh4.c | 26 +++++++++++-----
> arch/sh/mm/cache-sh7705.c | 26 ++++++++++------
> arch/sh/mm/cache.c | 52 ++++++++++++++++++--------------
> arch/sh/mm/kmap.c | 3 +-
> 8 files changed, 88 insertions(+), 55 deletions(-)
>
> diff --git a/arch/sh/include/asm/cacheflush.h b/arch/sh/include/asm/cacheflush.h
> index 481a664287e2..9fceef6f3e00 100644
> --- a/arch/sh/include/asm/cacheflush.h
> +++ b/arch/sh/include/asm/cacheflush.h
> @@ -13,9 +13,9 @@
> * - flush_cache_page(mm, vmaddr, pfn) flushes a single page
> * - flush_cache_range(vma, start, end) flushes a range of pages
> *
> - * - flush_dcache_page(pg) flushes(wback&invalidates) a page for dcache
> + * - flush_dcache_folio(folio) flushes(wback&invalidates) a folio for dcache
> * - flush_icache_range(start, end) flushes(invalidates) a range for icache
> - * - flush_icache_page(vma, pg) flushes(invalidates) a page for icache
> + * - flush_icache_pages(vma, pg, nr) flushes(invalidates) pages for icache
> * - flush_cache_sigtramp(vaddr) flushes the signal trampoline
> */
> extern void (*local_flush_cache_all)(void *args);
> @@ -23,9 +23,9 @@ extern void (*local_flush_cache_mm)(void *args);
> extern void (*local_flush_cache_dup_mm)(void *args);
> extern void (*local_flush_cache_page)(void *args);
> extern void (*local_flush_cache_range)(void *args);
> -extern void (*local_flush_dcache_page)(void *args);
> +extern void (*local_flush_dcache_folio)(void *args);
> extern void (*local_flush_icache_range)(void *args);
> -extern void (*local_flush_icache_page)(void *args);
> +extern void (*local_flush_icache_folio)(void *args);
> extern void (*local_flush_cache_sigtramp)(void *args);
>
> static inline void cache_noop(void *args) { }
> @@ -42,11 +42,18 @@ extern void flush_cache_page(struct vm_area_struct *vma,
> extern void flush_cache_range(struct vm_area_struct *vma,
> unsigned long start, unsigned long end);
> #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
> +static inline void flush_dcache_page(struct page *page)
> +{
> + flush_dcache_folio(page_folio(page));
> +}
> +
> extern void flush_icache_range(unsigned long start, unsigned long end);
> #define flush_icache_user_range flush_icache_range
> -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)
> extern void flush_cache_sigtramp(unsigned long address);
>
> struct flusher_data {
> diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h
> index 3ce30becf6df..1a8fdc3bc363 100644
> --- a/arch/sh/include/asm/pgtable.h
> +++ b/arch/sh/include/asm/pgtable.h
> @@ -102,13 +102,15 @@ extern void __update_cache(struct vm_area_struct *vma,
> extern void __update_tlb(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 *ptep)
> +static inline void update_mmu_cache_range(struct vm_area_struct *vma,
> + unsigned long address, pte_t *ptep, unsigned int nr)
> {
> pte_t pte = *ptep;
> __update_cache(vma, address, pte);
> __update_tlb(vma, address, pte);
> }
> +#define update_mmu_cache(vma, addr, ptep) \
> + update_mmu_cache_range(vma, addr, ptep, 1)
>
> extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
> extern void paging_init(void);
> diff --git a/arch/sh/include/asm/pgtable_32.h b/arch/sh/include/asm/pgtable_32.h
> index 21952b094650..676f3d4ef6ce 100644
> --- a/arch/sh/include/asm/pgtable_32.h
> +++ b/arch/sh/include/asm/pgtable_32.h
> @@ -307,14 +307,13 @@ static inline void set_pte(pte_t *ptep, pte_t pte)
> #define set_pte(pteptr, pteval) (*(pteptr) = pteval)
> #endif
>
> -#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.)
> */
> #define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval)
>
> +#define PFN_PTE_SHIFT PAGE_SHIFT
> #define pfn_pte(pfn, prot) \
> __pte(((unsigned long long)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
> #define pfn_pmd(pfn, prot) \
> @@ -323,7 +322,7 @@ static inline void set_pte(pte_t *ptep, pte_t pte)
> #define pte_none(x) (!pte_val(x))
> #define pte_present(x) ((x).pte_low & (_PAGE_PRESENT | _PAGE_PROTNONE))
>
> -#define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)
> +#define pte_clear(mm, addr, ptep) set_pte(ptep, __pte(0))
>
> #define pmd_none(x) (!pmd_val(x))
> #define pmd_present(x) (pmd_val(x))
> diff --git a/arch/sh/mm/cache-j2.c b/arch/sh/mm/cache-j2.c
> index f277862a11f5..9ac960214380 100644
> --- a/arch/sh/mm/cache-j2.c
> +++ b/arch/sh/mm/cache-j2.c
> @@ -55,9 +55,9 @@ void __init j2_cache_init(void)
> local_flush_cache_dup_mm = j2_flush_both;
> local_flush_cache_page = j2_flush_both;
> local_flush_cache_range = j2_flush_both;
> - local_flush_dcache_page = j2_flush_dcache;
> + local_flush_dcache_folio = j2_flush_dcache;
> local_flush_icache_range = j2_flush_icache;
> - local_flush_icache_page = j2_flush_icache;
> + local_flush_icache_folio = j2_flush_icache;
> local_flush_cache_sigtramp = j2_flush_icache;
>
> pr_info("Initial J2 CCR is %.8x\n", __raw_readl(j2_ccr_base));
> diff --git a/arch/sh/mm/cache-sh4.c b/arch/sh/mm/cache-sh4.c
> index 72c2e1b46c08..862046f26981 100644
> --- a/arch/sh/mm/cache-sh4.c
> +++ b/arch/sh/mm/cache-sh4.c
> @@ -107,19 +107,29 @@ static inline void flush_cache_one(unsigned long start, unsigned long phys)
> * Write back & invalidate the D-cache of the page.
> * (To avoid "alias" issues)
> */
> -static void sh4_flush_dcache_page(void *arg)
> +static void sh4_flush_dcache_folio(void *arg)
> {
> - struct page *page = arg;
> - unsigned long addr = (unsigned long)page_address(page);
> + struct folio *folio = arg;
> #ifndef CONFIG_SMP
> - struct address_space *mapping = page_mapping_file(page);
> + struct address_space *mapping = folio_flush_mapping(folio);
>
> if (mapping && !mapping_mapped(mapping))
> - clear_bit(PG_dcache_clean, &page->flags);
> + clear_bit(PG_dcache_clean, &folio->flags);
> else
> #endif
> - flush_cache_one(CACHE_OC_ADDRESS_ARRAY |
> - (addr & shm_align_mask), page_to_phys(page));
> + {
> + unsigned long pfn = folio_pfn(folio);
> + unsigned long addr = (unsigned long)folio_address(folio);
> + unsigned int i, nr = folio_nr_pages(folio);
> +
> + for (i = 0; i < nr; i++) {
> + flush_cache_one(CACHE_OC_ADDRESS_ARRAY |
> + (addr & shm_align_mask),
> + pfn * PAGE_SIZE);
> + addr += PAGE_SIZE;
> + pfn++;
> + }
> + }
>
> wmb();
> }
> @@ -379,7 +389,7 @@ void __init sh4_cache_init(void)
> __raw_readl(CCN_PRR));
>
> local_flush_icache_range = sh4_flush_icache_range;
> - local_flush_dcache_page = sh4_flush_dcache_page;
> + local_flush_dcache_folio = sh4_flush_dcache_folio;
> local_flush_cache_all = sh4_flush_cache_all;
> local_flush_cache_mm = sh4_flush_cache_mm;
> local_flush_cache_dup_mm = sh4_flush_cache_mm;
> diff --git a/arch/sh/mm/cache-sh7705.c b/arch/sh/mm/cache-sh7705.c
> index 9b63a53a5e46..b509a407588f 100644
> --- a/arch/sh/mm/cache-sh7705.c
> +++ b/arch/sh/mm/cache-sh7705.c
> @@ -132,15 +132,20 @@ static void __flush_dcache_page(unsigned long phys)
> * Write back & invalidate the D-cache of the page.
> * (To avoid "alias" issues)
> */
> -static void sh7705_flush_dcache_page(void *arg)
> +static void sh7705_flush_dcache_folio(void *arg)
> {
> - struct page *page = arg;
> - struct address_space *mapping = page_mapping_file(page);
> + struct folio *folio = arg;
> + struct address_space *mapping = folio_flush_mapping(folio);
>
> if (mapping && !mapping_mapped(mapping))
> - clear_bit(PG_dcache_clean, &page->flags);
> - else
> - __flush_dcache_page(__pa(page_address(page)));
> + clear_bit(PG_dcache_clean, &folio->flags);
> + else {
> + unsigned long pfn = folio_pfn(folio);
> + unsigned int i, nr = folio_nr_pages(folio);
> +
> + for (i = 0; i < nr; i++)
> + __flush_dcache_page((pfn + i) * PAGE_SIZE);
> + }
> }
>
> static void sh7705_flush_cache_all(void *args)
> @@ -176,19 +181,20 @@ static void sh7705_flush_cache_page(void *args)
> * Not entirely sure why this is necessary on SH3 with 32K cache but
> * without it we get occasional "Memory fault" when loading a program.
> */
> -static void sh7705_flush_icache_page(void *page)
> +static void sh7705_flush_icache_folio(void *arg)
> {
> - __flush_purge_region(page_address(page), PAGE_SIZE);
> + struct folio *folio = arg;
> + __flush_purge_region(folio_address(folio), folio_size(folio));
> }
>
> void __init sh7705_cache_init(void)
> {
> local_flush_icache_range = sh7705_flush_icache_range;
> - local_flush_dcache_page = sh7705_flush_dcache_page;
> + local_flush_dcache_folio = sh7705_flush_dcache_folio;
> local_flush_cache_all = sh7705_flush_cache_all;
> local_flush_cache_mm = sh7705_flush_cache_all;
> local_flush_cache_dup_mm = sh7705_flush_cache_all;
> local_flush_cache_range = sh7705_flush_cache_all;
> local_flush_cache_page = sh7705_flush_cache_page;
> - local_flush_icache_page = sh7705_flush_icache_page;
> + local_flush_icache_folio = sh7705_flush_icache_folio;
> }
> diff --git a/arch/sh/mm/cache.c b/arch/sh/mm/cache.c
> index 3aef78ceb820..9bcaa5619eab 100644
> --- a/arch/sh/mm/cache.c
> +++ b/arch/sh/mm/cache.c
> @@ -20,9 +20,9 @@ void (*local_flush_cache_mm)(void *args) = cache_noop;
> void (*local_flush_cache_dup_mm)(void *args) = cache_noop;
> void (*local_flush_cache_page)(void *args) = cache_noop;
> void (*local_flush_cache_range)(void *args) = cache_noop;
> -void (*local_flush_dcache_page)(void *args) = cache_noop;
> +void (*local_flush_dcache_folio)(void *args) = cache_noop;
> void (*local_flush_icache_range)(void *args) = cache_noop;
> -void (*local_flush_icache_page)(void *args) = cache_noop;
> +void (*local_flush_icache_folio)(void *args) = cache_noop;
> void (*local_flush_cache_sigtramp)(void *args) = cache_noop;
>
> void (*__flush_wback_region)(void *start, int size);
> @@ -61,15 +61,17 @@ void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
> unsigned long vaddr, void *dst, const void *src,
> unsigned long len)
> {
> - if (boot_cpu_data.dcache.n_aliases && page_mapcount(page) &&
> - test_bit(PG_dcache_clean, &page->flags)) {
> + struct folio *folio = page_folio(page);
> +
> + if (boot_cpu_data.dcache.n_aliases && folio_mapped(folio) &&
> + test_bit(PG_dcache_clean, &folio->flags)) {
> void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
> memcpy(vto, src, len);
> kunmap_coherent(vto);
> } else {
> memcpy(dst, src, len);
> if (boot_cpu_data.dcache.n_aliases)
> - clear_bit(PG_dcache_clean, &page->flags);
> + clear_bit(PG_dcache_clean, &folio->flags);
> }
>
> if (vma->vm_flags & VM_EXEC)
> @@ -80,27 +82,30 @@ void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
> unsigned long vaddr, void *dst, const void *src,
> unsigned long len)
> {
> + struct folio *folio = page_folio(page);
> +
> if (boot_cpu_data.dcache.n_aliases && page_mapcount(page) &&
> - test_bit(PG_dcache_clean, &page->flags)) {
> + test_bit(PG_dcache_clean, &folio->flags)) {
> void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
> memcpy(dst, vfrom, len);
> kunmap_coherent(vfrom);
> } else {
> memcpy(dst, src, len);
> if (boot_cpu_data.dcache.n_aliases)
> - clear_bit(PG_dcache_clean, &page->flags);
> + clear_bit(PG_dcache_clean, &folio->flags);
> }
> }
>
> void copy_user_highpage(struct page *to, struct page *from,
> unsigned long vaddr, struct vm_area_struct *vma)
> {
> + struct folio *src = page_folio(from);
> void *vfrom, *vto;
>
> vto = kmap_atomic(to);
>
> - if (boot_cpu_data.dcache.n_aliases && page_mapcount(from) &&
> - test_bit(PG_dcache_clean, &from->flags)) {
> + if (boot_cpu_data.dcache.n_aliases && folio_mapped(src) &&
> + test_bit(PG_dcache_clean, &src->flags)) {
> vfrom = kmap_coherent(from, vaddr);
> copy_page(vto, vfrom);
> kunmap_coherent(vfrom);
> @@ -136,27 +141,28 @@ EXPORT_SYMBOL(clear_user_highpage);
> void __update_cache(struct vm_area_struct *vma,
> unsigned long address, pte_t pte)
> {
> - struct page *page;
> unsigned long pfn = pte_pfn(pte);
>
> if (!boot_cpu_data.dcache.n_aliases)
> return;
>
> - page = pfn_to_page(pfn);
> if (pfn_valid(pfn)) {
> - int dirty = !test_and_set_bit(PG_dcache_clean, &page->flags);
> + struct folio *folio = page_folio(pfn_to_page(pfn));
> + int dirty = !test_and_set_bit(PG_dcache_clean, &folio->flags);
> if (dirty)
> - __flush_purge_region(page_address(page), PAGE_SIZE);
> + __flush_purge_region(folio_address(folio),
> + folio_size(folio));
> }
> }
>
> void __flush_anon_page(struct page *page, unsigned long vmaddr)
> {
> + struct folio *folio = page_folio(page);
> unsigned long addr = (unsigned long) page_address(page);
>
> if (pages_do_alias(addr, vmaddr)) {
> - if (boot_cpu_data.dcache.n_aliases && page_mapcount(page) &&
> - test_bit(PG_dcache_clean, &page->flags)) {
> + if (boot_cpu_data.dcache.n_aliases && folio_mapped(folio) &&
> + test_bit(PG_dcache_clean, &folio->flags)) {
> void *kaddr;
>
> kaddr = kmap_coherent(page, vmaddr);
> @@ -164,7 +170,8 @@ void __flush_anon_page(struct page *page, unsigned long vmaddr)
> /* __flush_purge_region((void *)kaddr, PAGE_SIZE); */
> kunmap_coherent(kaddr);
> } else
> - __flush_purge_region((void *)addr, PAGE_SIZE);
> + __flush_purge_region(folio_address(folio),
> + folio_size(folio));
> }
> }
>
> @@ -215,11 +222,11 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
> }
> EXPORT_SYMBOL(flush_cache_range);
>
> -void flush_dcache_page(struct page *page)
> +void flush_dcache_folio(struct folio *folio)
> {
> - cacheop_on_each_cpu(local_flush_dcache_page, page, 1);
> + cacheop_on_each_cpu(local_flush_dcache_folio, folio, 1);
> }
> -EXPORT_SYMBOL(flush_dcache_page);
> +EXPORT_SYMBOL(flush_dcache_folio);
>
> void flush_icache_range(unsigned long start, unsigned long end)
> {
> @@ -233,10 +240,11 @@ void flush_icache_range(unsigned long start, unsigned long end)
> }
> EXPORT_SYMBOL(flush_icache_range);
>
> -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)
> {
> - /* Nothing uses the VMA, so just pass the struct page along */
> - cacheop_on_each_cpu(local_flush_icache_page, page, 1);
> + /* Nothing uses the VMA, so just pass the folio along */
> + cacheop_on_each_cpu(local_flush_icache_folio, page_folio(page), 1);
> }
>
> void flush_cache_sigtramp(unsigned long address)
> diff --git a/arch/sh/mm/kmap.c b/arch/sh/mm/kmap.c
> index 73fd7cc99430..fa50e8f6e7a9 100644
> --- a/arch/sh/mm/kmap.c
> +++ b/arch/sh/mm/kmap.c
> @@ -27,10 +27,11 @@ void __init kmap_coherent_init(void)
>
> void *kmap_coherent(struct page *page, unsigned long addr)
> {
> + struct folio *folio = page_folio(page);
> enum fixed_addresses idx;
> unsigned long vaddr;
>
> - BUG_ON(!test_bit(PG_dcache_clean, &page->flags));
> + BUG_ON(!test_bit(PG_dcache_clean, &folio->flags));
>
> preempt_disable();
> pagefault_disable();

Doesn't build for me with CONFIG_WERROR:

CC arch/sh/kernel/asm-offsets.s
In file included from ./include/linux/mm.h:29,
from arch/sh/kernel/asm-offsets.c:14:
./include/linux/pgtable.h: In function 'ptep_test_and_clear_young':
./include/linux/pgtable.h:217:17: error: implicit declaration of function 'set_pte_at'; did you mean 'set_pte'? [-Werror=implicit-function-
declaration]
217 | set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
| ^~~~~~~~~~
| set_pte
cc1: some warnings being treated as errors
make[1]: *** [scripts/Makefile.build:114: arch/sh/kernel/asm-offsets.s] Error 1
make: *** [Makefile:1287: prepare0] Error 2

Adrian

--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer
`. `' Physicist
`- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913