Commit 78e7c5af authored by Anshuman Khandual's avatar Anshuman Khandual Committed by Linus Torvalds
Browse files

mm/special: create generic fallbacks for pte_special() and pte_mkspecial() 

Currently there are many platforms that dont enable ARCH_HAS_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 ARCH_HAS_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.

[anshuman.khandual@arm.com: use defined(CONFIG_ARCH_HAS_PTE_SPECIAL) in mips per Thomas]
  Link: http://lkml.kernel.org/r/1583851924-21603-1-git-send-email-anshuman.khandual@arm.com


Signed-off-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Acked-by: Guo Ren <guoren@kernel.org>			[csky]
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Acked-by: Stafford Horne <shorne@gmail.com>		[openrisc]
Acked-by: Helge Deller <deller@gmx.de>			[parisc]
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Sam Creasey <sammy@sammy.net>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Link: http://lkml.kernel.org/r/1583802551-15406-1-git-send-email-anshuman.khandual@arm.com


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6cb4d9a2

arch/alpha/include/asm/pgtable.h

+0 −2
Original line number Diff line number Diff line
@@ -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))

arch/arm/include/asm/pgtable-2level.h

+0 −2
Original line number Diff line number Diff line
@@ -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

arch/arm/include/asm/pgtable.h

+2 −13
Original line number Diff line number Diff line
@@ -243,19 +243,8 @@ 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)

{

arch/arm/mm/mmu.c

+14 −0
Original line number Diff line number Diff line
@@ -1646,3 +1646,17 @@ 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);

}

arch/csky/include/asm/pgtable.h

+0 −3
Original line number Diff line number Diff line
@@ -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;

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