Commit 974b9b2c authored by Mike Rapoport's avatar Mike Rapoport Committed by Linus Torvalds
Browse files

mm: consolidate pte_index() and pte_offset_*() definitions 

All architectures define pte_index() as

	(address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)

and all architectures define pte_offset_kernel() as an entry in the array
of PTEs indexed by the pte_index().

For the most architectures the pte_offset_kernel() implementation relies
on the availability of pmd_page_vaddr() that converts a PMD entry value to
the virtual address of the page containing PTEs array.

Let's move x86 definitions of the PTE accessors to the generic place in
<linux/pgtable.h> and then simply drop the respective definitions from the
other architectures.

The architectures that didn't provide pmd_page_vaddr() are updated to have
that defined.

The generic implementation of pte_offset_kernel() can be overridden by an
architecture and alpha makes use of this because it has special ordering
requirements for its version of pte_offset_kernel().

[rppt@linux.ibm.com: v2]
  Link: http://lkml.kernel.org/r/20200514170327.31389-11-rppt@kernel.org
[rppt@linux.ibm.com: update]
  Link: http://lkml.kernel.org/r/20200514170327.31389-12-rppt@kernel.org
[rppt@linux.ibm.com: update]
  Link: http://lkml.kernel.org/r/20200514170327.31389-13-rppt@kernel.org
[akpm@linux-foundation.org: fix x86 warning]
[sfr@canb.auug.org.au: fix powerpc build]
  Link: http://lkml.kernel.org/r/20200607153443.GB738695@linux.ibm.com



Signed-off-by: default avatarMike Rapoport <rppt@linux.ibm.com>
Signed-off-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-10-rppt@kernel.org


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e05c7b1f

arch/alpha/include/asm/pgtable.h

+2 −12
Original line number Diff line number Diff line
@@ -276,15 +276,6 @@ extern inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) &= ~_PAGE_FOW; return 
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; }



#define PAGE_DIR_OFFSET(tsk,address) pgd_offset((tsk),(address))



/* to find an entry in a kernel page-table-directory */

#define pgd_offset_k(address) pgd_offset(&init_mm, (address))



/* to find an entry in a page-table-directory. */

#define pgd_index(address)	(((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))

#define pgd_offset(mm, address)	((mm)->pgd+pgd_index(address))



/*

 * The smp_read_barrier_depends() in the following functions are required to

 * order the load of *dir (the pointer in the top level page table) with any
@@ -305,6 +296,7 @@ extern inline pmd_t * pmd_offset(pud_t * dir, unsigned long address) 
	smp_read_barrier_depends(); /* see above */

	return ret;

}

#define pmd_offset pmd_offset



/* Find an entry in the third-level page table.. */

extern inline pte_t * pte_offset_kernel(pmd_t * dir, unsigned long address)
@@ -314,9 +306,7 @@ extern inline pte_t * pte_offset_kernel(pmd_t * dir, unsigned long address) 
	smp_read_barrier_depends(); /* see above */

	return ret;

}



#define pte_offset_map(dir,addr)	pte_offset_kernel((dir),(addr))

#define pte_unmap(pte)			do { } while (0)

#define pte_offset_kernel pte_offset_kernel



extern pgd_t swapper_pg_dir[1024];

arch/arc/include/asm/pgtable.h

+0 −22
Original line number Diff line number Diff line
@@ -248,9 +248,6 @@ 
extern char empty_zero_page[PAGE_SIZE];

#define ZERO_PAGE(vaddr)	(virt_to_page(empty_zero_page))



#define pte_unmap(pte)		do { } while (0)

#define pte_unmap_nested(pte)		do { } while (0)



#define set_pte(pteptr, pteval)	((*(pteptr)) = (pteval))

#define set_pmd(pmdptr, pmdval)	(*(pmdptr) = pmdval)
@@ -282,18 +279,6 @@ static inline void pmd_set(pmd_t *pmdp, pte_t *ptep) 


/* Don't use virt_to_pfn for macros below: could cause truncations for PAE40*/

#define pte_pfn(pte)		(pte_val(pte) >> PAGE_SHIFT)

#define __pte_index(addr)	(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))



/*

 * pte_offset gets a @ptr to PMD entry (PGD in our 2-tier paging system)

 * and returns ptr to PTE entry corresponding to @addr

 */

#define pte_offset(dir, addr) ((pte_t *)(pmd_page_vaddr(*dir)) +\

					 __pte_index(addr))



/* No mapping of Page Tables in high mem etc, so following same as above */

#define pte_offset_kernel(dir, addr)		pte_offset(dir, addr)

#define pte_offset_map(dir, addr)		pte_offset(dir, addr)



/* Zoo of pte_xxx function */

#define pte_read(pte)		(pte_val(pte) & _PAGE_READ)
@@ -331,13 +316,6 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, 
	set_pte(ptep, pteval);

}



/*

 * All kernel related VM pages are in init's mm.

 */

#define pgd_offset_k(address)	pgd_offset(&init_mm, address)

#define pgd_index(addr)		((addr) >> PGDIR_SHIFT)

#define pgd_offset(mm, addr)	(((mm)->pgd)+pgd_index(addr))



/*

 * Macro to quickly access the PGD entry, utlising the fact that some

 * arch may cache the pointer to Page Directory of "current" task

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

+1 −0
Original line number Diff line number Diff line
@@ -187,6 +187,7 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr) 
{

	return (pmd_t *)pud;

}

#define pmd_offset pmd_offset



#define pmd_large(pmd)		(pmd_val(pmd) & 2)

#define pmd_leaf(pmd)		(pmd_val(pmd) & 2)

arch/arm/include/asm/pgtable-3level.h

+0 −7
Original line number Diff line number Diff line
@@ -133,13 +133,6 @@ static inline pmd_t *pud_page_vaddr(pud_t pud) 
	return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK);

}



/* Find an entry in the second-level page table.. */

#define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))

static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)

{

	return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);

}



#define pmd_bad(pmd)		(!(pmd_val(pmd) & 2))



#define copy_pmd(pmdpd,pmdps)		\

arch/arm/include/asm/pgtable-nommu.h

+0 −1
Original line number Diff line number Diff line
@@ -22,7 +22,6 @@ 
#define pgd_bad(pgd)		(0)

#define pgd_clear(pgdp)

#define kern_addr_valid(addr)	(1)

#define	pmd_offset(a, b)	((void *)0)

/* FIXME */

/*

 * PMD_SHIFT determines the size of the area a second-level page table can map

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