[v5,24/38] sh: Implement the new page table range API

  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@infradead.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: linux-sh@vger.kernel.org
---
 arch/sh/include/asm/cacheflush.h | 21 ++++++++-----
 arch/sh/include/asm/pgtable.h    |  7 +++--
 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, 89 insertions(+), 55 deletions(-)
  

Hi Matthew!

On Mon, 2023-07-10 at 21:43 +0100, 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@infradead.org>
> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
> Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
> Cc: Rich Felker <dalias@libc.org>
> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
> Cc: linux-sh@vger.kernel.org
> ---
>  arch/sh/include/asm/cacheflush.h | 21 ++++++++-----
>  arch/sh/include/asm/pgtable.h    |  7 +++--
>  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, 89 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..729f5c6225fb 100644
> --- a/arch/sh/include/asm/pgtable.h
> +++ b/arch/sh/include/asm/pgtable.h
> @@ -102,13 +102,16 @@ 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_fault *vmf,
> +		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(NULL, 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();

What's the best way to test this? Just build Andrew's kernel?

I would like to give it a go on my SH7785LCR to be sure nothing breaks.

Adrian
  

On 7/11/2023 12:00 PM, John Paul Adrian Glaubitz wrote:
> What's the best way to test this? Just build Andrew's kernel?
I didn't see the patchset shown on:
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git/log/?h=mm-unstable
yet. I believe the patchset will be in mm-unstable soon.

From the cover letter:
The point of all this is better performance, and Fengwei Yin has
measured improvement on x86.  I suspect you'll see improvement on
your architecture too.  Try the new will-it-scale test mentioned here:
https://lore.kernel.org/linux-mm/20230206140639.538867-5-fengwei.yin@intel.com/
You'll need to run it on an XFS filesystem and have
CONFIG_TRANSPARENT_HUGEPAGE set.

It's for performance testing. For functionality, I used:
   - System boot/reboot.
   - Using browser to access internet, Thunderbird to check email.
   - Build kernel.


Regards
Yin, Fengwei

> 
> I would like to give it a go on my SH7785LCR to be sure nothing breaks.