Re: [PATCH] mm/special: Create generic fallbacks for pte_special() and pte_mkspecial()

From: Guo Ren
Date: Sun Mar 01 2020 - 23:49:11 EST

Acked with csky part.

On Mon, Mar 2, 2020 at 9:56 AM Anshuman Khandual
<anshuman.khandual@xxxxxxx> wrote:
>
> Currently there are many platforms that dont enable HAVE_ARCH_PTE_SPECIAL
> but required to define quite similar fallback stubs for special page table
> entry helpers such as pte_special() and pte_mkspecial(), as they get build
> in generic MM without a config check. This creates two generic fallback
> stub definitions for these helpers, eliminating much code duplication.
>
> mips platform has a special case where pte_special() and pte_mkspecial()
> visibility is wider than what HAVE_ARCH_PTE_SPECIAL enablement requires.
> This restricts those symbol visibility in order to avoid redefinitions
> which is now exposed through this new generic stubs and subsequent build
> failure. arm platform set_pte_at() definition needs to be moved into a C
> file just to prevent a build failure.
>
> Cc: Richard Henderson <rth@xxxxxxxxxxx>
> Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
> Cc: Matt Turner <mattst88@xxxxxxxxx>
> Cc: Russell King <linux@xxxxxxxxxxxxxxx>
> Cc: Guo Ren <guoren@xxxxxxxxxx>
> Cc: Brian Cain <bcain@xxxxxxxxxxxxxx>
> Cc: Tony Luck <tony.luck@xxxxxxxxx>
> Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> Cc: Sam Creasey <sammy@xxxxxxxxx>
> Cc: Michal Simek <monstr@xxxxxxxxx>
> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> Cc: Paul Burton <paulburton@xxxxxxxxxx>
> Cc: Nick Hu <nickhu@xxxxxxxxxxxxx>
> Cc: Greentime Hu <green.hu@xxxxxxxxx>
> Cc: Vincent Chen <deanbo422@xxxxxxxxx>
> Cc: Ley Foon Tan <ley.foon.tan@xxxxxxxxx>
> Cc: Jonas Bonn <jonas@xxxxxxxxxxxx>
> Cc: Stefan Kristiansson <stefan.kristiansson@xxxxxxxxxxxxx>
> Cc: Stafford Horne <shorne@xxxxxxxxx>
> Cc: "James E.J. Bottomley" <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
> Cc: Helge Deller <deller@xxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Jeff Dike <jdike@xxxxxxxxxxx>
> Cc: Richard Weinberger <richard@xxxxxx>
> Cc: Anton Ivanov <anton.ivanov@xxxxxxxxxxxxxxxxxx>
> Cc: Guan Xuetao <gxt@xxxxxxxxxx>
> Cc: Chris Zankel <chris@xxxxxxxxxx>
> Cc: Max Filippov <jcmvbkbc@xxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: linux-alpha@xxxxxxxxxxxxxxx
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-csky@xxxxxxxxxxxxxxx
> Cc: linux-hexagon@xxxxxxxxxxxxxxx
> Cc: linux-ia64@xxxxxxxxxxxxxxx
> Cc: linux-m68k@xxxxxxxxxxxxxxxxxxxx
> Cc: linux-mips@xxxxxxxxxxxxxxx
> Cc: nios2-dev@xxxxxxxxxxxxxxxxxxxxxx
> Cc: openrisc@xxxxxxxxxxxxxxxxxxxx
> Cc: linux-parisc@xxxxxxxxxxxxxxx
> Cc: sparclinux@xxxxxxxxxxxxxxx
> Cc: linux-um@xxxxxxxxxxxxxxxxxxx
> Cc: linux-xtensa@xxxxxxxxxxxxxxxx
> Cc: linux-arch@xxxxxxxxxxxxxxx
> Cc: linux-mm@xxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> ---
> Build tested on multiple platforms but boot tested only for arm64.
>
> arch/alpha/include/asm/pgtable.h | 2 --
> arch/arm/include/asm/pgtable-2level.h | 2 --
> arch/arm/include/asm/pgtable.h | 15 ++------
> arch/arm/mm/mmu.c | 14 ++++++++
> arch/csky/include/asm/pgtable.h | 3 --
> arch/hexagon/include/asm/pgtable.h | 2 --
> arch/ia64/include/asm/pgtable.h | 2 --
> arch/m68k/include/asm/mcf_pgtable.h | 10 ------
> arch/m68k/include/asm/motorola_pgtable.h | 2 --
> arch/m68k/include/asm/sun3_pgtable.h | 2 --
> arch/microblaze/include/asm/pgtable.h | 4 ---
> arch/mips/include/asm/pgtable.h | 44 ++++++++++++++++--------
> arch/nds32/include/asm/pgtable.h | 9 -----
> arch/nios2/include/asm/pgtable.h | 3 --
> arch/openrisc/include/asm/pgtable.h | 2 --
> arch/parisc/include/asm/pgtable.h | 2 --
> arch/sparc/include/asm/pgtable_32.h | 7 ----
> arch/um/include/asm/pgtable.h | 10 ------
> arch/unicore32/include/asm/pgtable.h | 3 --
> arch/xtensa/include/asm/pgtable.h | 3 --
> include/linux/mm.h | 12 +++++++
> 21 files changed, 58 insertions(+), 95 deletions(-)
>
> diff --git a/arch/alpha/include/asm/pgtable.h b/arch/alpha/include/asm/pgtable.h
> index 299791ce14b6..0267aa8a4f86 100644
> --- a/arch/alpha/include/asm/pgtable.h
> +++ b/arch/alpha/include/asm/pgtable.h
> @@ -268,7 +268,6 @@ extern inline void pud_clear(pud_t * pudp) { pud_val(*pudp) = 0; }
> extern inline int pte_write(pte_t pte) { return !(pte_val(pte) & _PAGE_FOW); }
> extern inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
> extern inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
> -extern inline int pte_special(pte_t pte) { return 0; }
>
> extern inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) |= _PAGE_FOW; return pte; }
> extern inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~(__DIRTY_BITS); return pte; }
> @@ -276,7 +275,6 @@ extern inline pte_t pte_mkold(pte_t pte) { pte_val(pte) &= ~(__ACCESS_BITS); ret
> extern inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) &= ~_PAGE_FOW; return pte; }
> extern inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) |= __DIRTY_BITS; return pte; }
> extern inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) |= __ACCESS_BITS; return pte; }
> -extern inline pte_t pte_mkspecial(pte_t pte) { return pte; }
>
> #define PAGE_DIR_OFFSET(tsk,address) pgd_offset((tsk),(address))
>
> diff --git a/arch/arm/include/asm/pgtable-2level.h b/arch/arm/include/asm/pgtable-2level.h
> index 0d3ea35c97fe..9e084a464a97 100644
> --- a/arch/arm/include/asm/pgtable-2level.h
> +++ b/arch/arm/include/asm/pgtable-2level.h
> @@ -211,8 +211,6 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
> #define pmd_addr_end(addr,end) (end)
>
> #define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,pte,ext)
> -#define pte_special(pte) (0)
> -static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
>
> /*
> * We don't have huge page support for short descriptors, for the moment
> diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
> index eabcb48a7840..556468240ba5 100644
> --- a/arch/arm/include/asm/pgtable.h
> +++ b/arch/arm/include/asm/pgtable.h
> @@ -252,19 +252,8 @@ static inline void __sync_icache_dcache(pte_t pteval)
> extern void __sync_icache_dcache(pte_t pteval);
> #endif
>
> -static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pteval)
> -{
> - unsigned long ext = 0;
> -
> - if (addr < TASK_SIZE && pte_valid_user(pteval)) {
> - if (!pte_special(pteval))
> - __sync_icache_dcache(pteval);
> - ext |= PTE_EXT_NG;
> - }
> -
> - set_pte_ext(ptep, pteval, ext);
> -}
> +void set_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pteval);
>
> static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
> {
> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
> index 5d0d0f86e790..16e9b041d7cf 100644
> --- a/arch/arm/mm/mmu.c
> +++ b/arch/arm/mm/mmu.c
> @@ -1672,3 +1672,17 @@ void __init early_mm_init(const struct machine_desc *mdesc)
> build_mem_type_table();
> early_paging_init(mdesc);
> }
> +
> +void set_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pteval)
> +{
> + unsigned long ext = 0;
> +
> + if (addr < TASK_SIZE && pte_valid_user(pteval)) {
> + if (!pte_special(pteval))
> + __sync_icache_dcache(pteval);
> + ext |= PTE_EXT_NG;
> + }
> +
> + set_pte_ext(ptep, pteval, ext);
> +}
> diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h
> index 9b7764cb7645..9ab4a445ad99 100644
> --- a/arch/csky/include/asm/pgtable.h
> +++ b/arch/csky/include/asm/pgtable.h
> @@ -110,9 +110,6 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
> extern void load_pgd(unsigned long pg_dir);
> extern pte_t invalid_pte_table[PTRS_PER_PTE];
>
> -static inline int pte_special(pte_t pte) { return 0; }
> -static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
> -
> static inline void set_pte(pte_t *p, pte_t pte)
> {
> *p = pte;
> diff --git a/arch/hexagon/include/asm/pgtable.h b/arch/hexagon/include/asm/pgtable.h
> index 2fec20ad939e..d383e8bea5b2 100644
> --- a/arch/hexagon/include/asm/pgtable.h
> +++ b/arch/hexagon/include/asm/pgtable.h
> @@ -158,8 +158,6 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* located in head.S */
>
> /* Seems to be zero even in architectures where the zero page is firewalled? */
> #define FIRST_USER_ADDRESS 0UL
> -#define pte_special(pte) 0
> -#define pte_mkspecial(pte) (pte)
>
> /* HUGETLB not working currently */
> #ifdef CONFIG_HUGETLB_PAGE
> diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h
> index d602e7c622db..0e7b645b76c6 100644
> --- a/arch/ia64/include/asm/pgtable.h
> +++ b/arch/ia64/include/asm/pgtable.h
> @@ -298,7 +298,6 @@ extern unsigned long VMALLOC_END;
> #define pte_exec(pte) ((pte_val(pte) & _PAGE_AR_RX) != 0)
> #define pte_dirty(pte) ((pte_val(pte) & _PAGE_D) != 0)
> #define pte_young(pte) ((pte_val(pte) & _PAGE_A) != 0)
> -#define pte_special(pte) 0
>
> /*
> * Note: we convert AR_RWX to AR_RX and AR_RW to AR_R by clearing the 2nd bit in the
> @@ -311,7 +310,6 @@ extern unsigned long VMALLOC_END;
> #define pte_mkclean(pte) (__pte(pte_val(pte) & ~_PAGE_D))
> #define pte_mkdirty(pte) (__pte(pte_val(pte) | _PAGE_D))
> #define pte_mkhuge(pte) (__pte(pte_val(pte)))
> -#define pte_mkspecial(pte) (pte)
>
> /*
> * Because ia64's Icache and Dcache is not coherent (on a cpu), we need to
> diff --git a/arch/m68k/include/asm/mcf_pgtable.h b/arch/m68k/include/asm/mcf_pgtable.h
> index b9f45aeded25..0031cd387b75 100644
> --- a/arch/m68k/include/asm/mcf_pgtable.h
> +++ b/arch/m68k/include/asm/mcf_pgtable.h
> @@ -235,11 +235,6 @@ static inline int pte_young(pte_t pte)
> return pte_val(pte) & CF_PAGE_ACCESSED;
> }
>
> -static inline int pte_special(pte_t pte)
> -{
> - return 0;
> -}
> -
> static inline pte_t pte_wrprotect(pte_t pte)
> {
> pte_val(pte) &= ~CF_PAGE_WRITABLE;
> @@ -312,11 +307,6 @@ static inline pte_t pte_mkcache(pte_t pte)
> return pte;
> }
>
> -static inline pte_t pte_mkspecial(pte_t pte)
> -{
> - return pte;
> -}
> -
> #define swapper_pg_dir kernel_pg_dir
> extern pgd_t kernel_pg_dir[PTRS_PER_PGD];
>
> diff --git a/arch/m68k/include/asm/motorola_pgtable.h b/arch/m68k/include/asm/motorola_pgtable.h
> index 62bedc61f110..a6f4b96d674e 100644
> --- a/arch/m68k/include/asm/motorola_pgtable.h
> +++ b/arch/m68k/include/asm/motorola_pgtable.h
> @@ -168,7 +168,6 @@ static inline void pud_set(pud_t *pudp, pmd_t *pmdp)
> static inline int pte_write(pte_t pte) { return !(pte_val(pte) & _PAGE_RONLY); }
> static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
> static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
> -static inline int pte_special(pte_t pte) { return 0; }
>
> static inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) |= _PAGE_RONLY; return pte; }
> static inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~_PAGE_DIRTY; return pte; }
> @@ -186,7 +185,6 @@ static inline pte_t pte_mkcache(pte_t pte)
> pte_val(pte) = (pte_val(pte) & _CACHEMASK040) | m68k_supervisor_cachemode;
> return pte;
> }
> -static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
>
> #define PAGE_DIR_OFFSET(tsk,address) pgd_offset((tsk),(address))
>
> diff --git a/arch/m68k/include/asm/sun3_pgtable.h b/arch/m68k/include/asm/sun3_pgtable.h
> index bc4155264810..0caa18a08437 100644
> --- a/arch/m68k/include/asm/sun3_pgtable.h
> +++ b/arch/m68k/include/asm/sun3_pgtable.h
> @@ -155,7 +155,6 @@ static inline void pmd_clear (pmd_t *pmdp) { pmd_val (*pmdp) = 0; }
> static inline int pte_write(pte_t pte) { return pte_val(pte) & SUN3_PAGE_WRITEABLE; }
> static inline int pte_dirty(pte_t pte) { return pte_val(pte) & SUN3_PAGE_MODIFIED; }
> static inline int pte_young(pte_t pte) { return pte_val(pte) & SUN3_PAGE_ACCESSED; }
> -static inline int pte_special(pte_t pte) { return 0; }
>
> static inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) &= ~SUN3_PAGE_WRITEABLE; return pte; }
> static inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~SUN3_PAGE_MODIFIED; return pte; }
> @@ -168,7 +167,6 @@ static inline pte_t pte_mknocache(pte_t pte) { pte_val(pte) |= SUN3_PAGE_NOCACHE
> //static inline pte_t pte_mkcache(pte_t pte) { pte_val(pte) &= SUN3_PAGE_NOCACHE; return pte; }
> // until then, use:
> static inline pte_t pte_mkcache(pte_t pte) { return pte; }
> -static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
>
> extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
> extern pgd_t kernel_pg_dir[PTRS_PER_PGD];
> diff --git a/arch/microblaze/include/asm/pgtable.h b/arch/microblaze/include/asm/pgtable.h
> index 2def331f9e2c..db9bdfcf46b7 100644
> --- a/arch/microblaze/include/asm/pgtable.h
> +++ b/arch/microblaze/include/asm/pgtable.h
> @@ -80,10 +80,6 @@ extern pte_t *va_to_pte(unsigned long address);
> * Undefined behaviour if not..
> */
>
> -static inline int pte_special(pte_t pte) { return 0; }
> -
> -static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
> -
> /* Start and end of the vmalloc area. */
> /* Make sure to map the vmalloc area above the pinned kernel memory area
> of 32Mb. */
> diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
> index aef5378f909c..8e4e4be1ca00 100644
> --- a/arch/mips/include/asm/pgtable.h
> +++ b/arch/mips/include/asm/pgtable.h
> @@ -269,6 +269,36 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
> */
> extern pgd_t swapper_pg_dir[];
>
> +/*
> + * Platform specific pte_special() and pte_mkspecial() definitions
> + * are required only when ARCH_HAS_PTE_SPECIAL is enabled.
> + */
> +#if !defined(CONFIG_32BIT) && !defined(CONFIG_CPU_HAS_RIXI)
> +#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
> +static inline int pte_special(pte_t pte)
> +{
> + return pte.pte_low & _PAGE_SPECIAL;
> +}
> +
> +static inline pte_t pte_mkspecial(pte_t pte)
> +{
> + pte.pte_low |= _PAGE_SPECIAL;
> + return pte;
> +}
> +#else
> +static inline int pte_special(pte_t pte)
> +{
> + return pte_val(pte) & _PAGE_SPECIAL;
> +}
> +
> +static inline pte_t pte_mkspecial(pte_t pte)
> +{
> + pte_val(pte) |= _PAGE_SPECIAL;
> + return pte;
> +}
> +#endif
> +#endif
> +
> /*
> * The following only work if pte_present() is true.
> * Undefined behaviour if not..
> @@ -277,7 +307,6 @@ extern pgd_t swapper_pg_dir[];
> static inline int pte_write(pte_t pte) { return pte.pte_low & _PAGE_WRITE; }
> static inline int pte_dirty(pte_t pte) { return pte.pte_low & _PAGE_MODIFIED; }
> static inline int pte_young(pte_t pte) { return pte.pte_low & _PAGE_ACCESSED; }
> -static inline int pte_special(pte_t pte) { return pte.pte_low & _PAGE_SPECIAL; }
>
> static inline pte_t pte_wrprotect(pte_t pte)
> {
> @@ -338,17 +367,10 @@ static inline pte_t pte_mkyoung(pte_t pte)
> }
> return pte;
> }
> -
> -static inline pte_t pte_mkspecial(pte_t pte)
> -{
> - pte.pte_low |= _PAGE_SPECIAL;
> - return pte;
> -}
> #else
> static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; }
> static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_MODIFIED; }
> static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
> -static inline int pte_special(pte_t pte) { return pte_val(pte) & _PAGE_SPECIAL; }
>
> static inline pte_t pte_wrprotect(pte_t pte)
> {
> @@ -392,12 +414,6 @@ static inline pte_t pte_mkyoung(pte_t pte)
> return pte;
> }
>
> -static inline pte_t pte_mkspecial(pte_t pte)
> -{
> - pte_val(pte) |= _PAGE_SPECIAL;
> - return pte;
> -}
> -
> #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
> static inline int pte_huge(pte_t pte) { return pte_val(pte) & _PAGE_HUGE; }
>
> diff --git a/arch/nds32/include/asm/pgtable.h b/arch/nds32/include/asm/pgtable.h
> index 6abc58ac406d..476cc4dd1709 100644
> --- a/arch/nds32/include/asm/pgtable.h
> +++ b/arch/nds32/include/asm/pgtable.h
> @@ -286,15 +286,6 @@ PTE_BIT_FUNC(mkclean, &=~_PAGE_D);
> PTE_BIT_FUNC(mkdirty, |=_PAGE_D);
> PTE_BIT_FUNC(mkold, &=~_PAGE_YOUNG);
> PTE_BIT_FUNC(mkyoung, |=_PAGE_YOUNG);
> -static inline int pte_special(pte_t pte)
> -{
> - return 0;
> -}
> -
> -static inline pte_t pte_mkspecial(pte_t pte)
> -{
> - return pte;
> -}
>
> /*
> * Mark the prot value as uncacheable and unbufferable.
> diff --git a/arch/nios2/include/asm/pgtable.h b/arch/nios2/include/asm/pgtable.h
> index 99985d8b7166..f98b7f4519ba 100644
> --- a/arch/nios2/include/asm/pgtable.h
> +++ b/arch/nios2/include/asm/pgtable.h
> @@ -113,7 +113,6 @@ static inline int pte_dirty(pte_t pte) \
> { return pte_val(pte) & _PAGE_DIRTY; }
> static inline int pte_young(pte_t pte) \
> { return pte_val(pte) & _PAGE_ACCESSED; }
> -static inline int pte_special(pte_t pte) { return 0; }
>
> #define pgprot_noncached pgprot_noncached
>
> @@ -168,8 +167,6 @@ static inline pte_t pte_mkdirty(pte_t pte)
> return pte;
> }
>
> -static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
> -
> static inline pte_t pte_mkyoung(pte_t pte)
> {
> pte_val(pte) |= _PAGE_ACCESSED;
> diff --git a/arch/openrisc/include/asm/pgtable.h b/arch/openrisc/include/asm/pgtable.h
> index 248d22d8faa7..7f3fb9ceb083 100644
> --- a/arch/openrisc/include/asm/pgtable.h
> +++ b/arch/openrisc/include/asm/pgtable.h
> @@ -236,8 +236,6 @@ static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; }
> static inline int pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_EXEC; }
> static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
> static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
> -static inline int pte_special(pte_t pte) { return 0; }
> -static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
>
> static inline pte_t pte_wrprotect(pte_t pte)
> {
> diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
> index f0a365950536..9832c73a7021 100644
> --- a/arch/parisc/include/asm/pgtable.h
> +++ b/arch/parisc/include/asm/pgtable.h
> @@ -377,7 +377,6 @@ static inline void pud_clear(pud_t *pud) {
> static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
> static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
> static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; }
> -static inline int pte_special(pte_t pte) { return 0; }
>
> static inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~_PAGE_DIRTY; return pte; }
> static inline pte_t pte_mkold(pte_t pte) { pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
> @@ -385,7 +384,6 @@ static inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) &= ~_PAGE_WRITE; ret
> static inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) |= _PAGE_DIRTY; return pte; }
> static inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) |= _PAGE_ACCESSED; return pte; }
> static inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) |= _PAGE_WRITE; return pte; }
> -static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
>
> /*
> * Huge pte definitions.
> diff --git a/arch/sparc/include/asm/pgtable_32.h b/arch/sparc/include/asm/pgtable_32.h
> index 6d6f44c0cad9..0de659ae0ba4 100644
> --- a/arch/sparc/include/asm/pgtable_32.h
> +++ b/arch/sparc/include/asm/pgtable_32.h
> @@ -223,11 +223,6 @@ static inline int pte_young(pte_t pte)
> return pte_val(pte) & SRMMU_REF;
> }
>
> -static inline int pte_special(pte_t pte)
> -{
> - return 0;
> -}
> -
> static inline pte_t pte_wrprotect(pte_t pte)
> {
> return __pte(pte_val(pte) & ~SRMMU_WRITE);
> @@ -258,8 +253,6 @@ static inline pte_t pte_mkyoung(pte_t pte)
> return __pte(pte_val(pte) | SRMMU_REF);
> }
>
> -#define pte_mkspecial(pte) (pte)
> -
> #define pfn_pte(pfn, prot) mk_pte(pfn_to_page(pfn), prot)
>
> static inline unsigned long pte_pfn(pte_t pte)
> diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h
> index 2daa58df2190..b5ddf5d98bd5 100644
> --- a/arch/um/include/asm/pgtable.h
> +++ b/arch/um/include/asm/pgtable.h
> @@ -167,11 +167,6 @@ static inline int pte_newprot(pte_t pte)
> return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
> }
>
> -static inline int pte_special(pte_t pte)
> -{
> - return 0;
> -}
> -
> /*
> * =================================
> * Flags setting section.
> @@ -247,11 +242,6 @@ static inline pte_t pte_mknewpage(pte_t pte)
> return(pte);
> }
>
> -static inline pte_t pte_mkspecial(pte_t pte)
> -{
> - return(pte);
> -}
> -
> static inline void set_pte(pte_t *pteptr, pte_t pteval)
> {
> pte_copy(*pteptr, pteval);
> diff --git a/arch/unicore32/include/asm/pgtable.h b/arch/unicore32/include/asm/pgtable.h
> index c8f7ba12f309..3b8731b3a937 100644
> --- a/arch/unicore32/include/asm/pgtable.h
> +++ b/arch/unicore32/include/asm/pgtable.h
> @@ -177,7 +177,6 @@ extern struct page *empty_zero_page;
> #define pte_dirty(pte) (pte_val(pte) & PTE_DIRTY)
> #define pte_young(pte) (pte_val(pte) & PTE_YOUNG)
> #define pte_exec(pte) (pte_val(pte) & PTE_EXEC)
> -#define pte_special(pte) (0)
>
> #define PTE_BIT_FUNC(fn, op) \
> static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
> @@ -189,8 +188,6 @@ PTE_BIT_FUNC(mkdirty, |= PTE_DIRTY);
> PTE_BIT_FUNC(mkold, &= ~PTE_YOUNG);
> PTE_BIT_FUNC(mkyoung, |= PTE_YOUNG);
>
> -static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
> -
> /*
> * Mark the prot value as uncacheable.
> */
> diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h
> index 27ac17c9da09..8be0c0568c50 100644
> --- a/arch/xtensa/include/asm/pgtable.h
> +++ b/arch/xtensa/include/asm/pgtable.h
> @@ -266,7 +266,6 @@ static inline void paging_init(void) { }
> static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITABLE; }
> static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
> static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
> -static inline int pte_special(pte_t pte) { return 0; }
>
> static inline pte_t pte_wrprotect(pte_t pte)
> { pte_val(pte) &= ~(_PAGE_WRITABLE | _PAGE_HW_WRITE); return pte; }
> @@ -280,8 +279,6 @@ static inline pte_t pte_mkyoung(pte_t pte)
> { pte_val(pte) |= _PAGE_ACCESSED; return pte; }
> static inline pte_t pte_mkwrite(pte_t pte)
> { pte_val(pte) |= _PAGE_WRITABLE; return pte; }
> -static inline pte_t pte_mkspecial(pte_t pte)
> - { return pte; }
>
> #define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) & ~_PAGE_CA_MASK))
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 52269e56c514..79ed4ad2a954 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -1720,6 +1720,18 @@ static inline void sync_mm_rss(struct mm_struct *mm)
> }
> #endif
>
> +#ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
> +static inline int pte_special(pte_t pte)
> +{
> + return 0;
> +}
> +
> +static inline pte_t pte_mkspecial(pte_t pte)
> +{
> + return pte;
> +}
> +#endif
> +
> #ifndef CONFIG_ARCH_HAS_PTE_DEVMAP
> static inline int pte_devmap(pte_t pte)
> {
> --
> 2.20.1
>


--
Best Regards
Guo Ren

ML: https://lore.kernel.org/linux-csky/