Commit b2787370 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Linus Torvalds
Browse files

mips, thp: remove infrastructure for handling splitting PMDs 



With new refcounting we don't need to mark PMDs splitting.  Let's drop
code to handle this.

pmdp_splitting_flush() is not needed too: on splitting PMD we will do
pmdp_clear_flush() + set_pte_at().  pmdp_clear_flush() will do IPI as
needed for fast_gup.

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0ebd7446

arch/mips/include/asm/pgtable-bits.h

+4 −6
Original line number Diff line number Diff line
@@ -131,14 +131,12 @@ 
/* Huge TLB page */

#define _PAGE_HUGE_SHIFT	(_PAGE_MODIFIED_SHIFT + 1)

#define _PAGE_HUGE		(1 << _PAGE_HUGE_SHIFT)

#define _PAGE_SPLITTING_SHIFT	(_PAGE_HUGE_SHIFT + 1)

#define _PAGE_SPLITTING		(1 << _PAGE_SPLITTING_SHIFT)

#endif	/* CONFIG_64BIT && CONFIG_MIPS_HUGE_TLB_SUPPORT */



#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)

/* XI - page cannot be executed */

#ifdef _PAGE_SPLITTING_SHIFT

#define _PAGE_NO_EXEC_SHIFT	(_PAGE_SPLITTING_SHIFT + 1)

#ifdef _PAGE_HUGE_SHIFT

#define _PAGE_NO_EXEC_SHIFT	(_PAGE_HUGE_SHIFT + 1)

#else

#define _PAGE_NO_EXEC_SHIFT	(_PAGE_MODIFIED_SHIFT + 1)

#endif
@@ -153,8 +151,8 @@ 


#if defined(_PAGE_NO_READ_SHIFT)

#define _PAGE_GLOBAL_SHIFT	(_PAGE_NO_READ_SHIFT + 1)

#elif defined(_PAGE_SPLITTING_SHIFT)

#define _PAGE_GLOBAL_SHIFT	(_PAGE_SPLITTING_SHIFT + 1)

#elif defined(_PAGE_HUGE_SHIFT)

#define _PAGE_GLOBAL_SHIFT	(_PAGE_HUGE_SHIFT + 1)

#else

#define _PAGE_GLOBAL_SHIFT	(_PAGE_MODIFIED_SHIFT + 1)

#endif

arch/mips/include/asm/pgtable.h

+0 −18
Original line number Diff line number Diff line
@@ -482,27 +482,9 @@ static inline pmd_t pmd_mkhuge(pmd_t pmd) 
	return pmd;

}



static inline int pmd_trans_splitting(pmd_t pmd)

{

	return !!(pmd_val(pmd) & _PAGE_SPLITTING);

}



static inline pmd_t pmd_mksplitting(pmd_t pmd)

{

	pmd_val(pmd) |= _PAGE_SPLITTING;



	return pmd;

}



extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,

		       pmd_t *pmdp, pmd_t pmd);



#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH

/* Extern to avoid header file madness */

extern void pmdp_splitting_flush(struct vm_area_struct *vma,

					unsigned long address,

					pmd_t *pmdp);



#define __HAVE_ARCH_PMD_WRITE

static inline int pmd_write(pmd_t pmd)

{

arch/mips/mm/gup.c

+1 −12
Original line number Diff line number Diff line
@@ -107,18 +107,7 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end, 
		pmd_t pmd = *pmdp;



		next = pmd_addr_end(addr, end);

		/*

		 * The pmd_trans_splitting() check below explains why

		 * pmdp_splitting_flush has to flush the tlb, to stop

		 * this gup-fast code from running while we set the

		 * splitting bit in the pmd. Returning zero will take

		 * the slow path that will call wait_split_huge_page()

		 * if the pmd is still in splitting state. gup-fast

		 * can't because it has irq disabled and

		 * wait_split_huge_page() would never return as the

		 * tlb flush IPI wouldn't run.

		 */

		if (pmd_none(pmd) || pmd_trans_splitting(pmd))

		if (pmd_none(pmd))

			return 0;

		if (unlikely(pmd_huge(pmd))) {

			if (!gup_huge_pmd(pmd, addr, next, write, pages,nr))

arch/mips/mm/pgtable-64.c

+0 −14
Original line number Diff line number Diff line
@@ -62,20 +62,6 @@ void pmd_init(unsigned long addr, unsigned long pagetable) 
}

#endif



#ifdef CONFIG_TRANSPARENT_HUGEPAGE



void pmdp_splitting_flush(struct vm_area_struct *vma,

			 unsigned long address,

			 pmd_t *pmdp)

{

	if (!pmd_trans_splitting(*pmdp)) {

		pmd_t pmd = pmd_mksplitting(*pmdp);

		set_pmd_at(vma->vm_mm, address, pmdp, pmd);

	}

}



#endif



pmd_t mk_pmd(struct page *page, pgprot_t prot)

{

	pmd_t pmd;

arch/mips/mm/tlbex.c

+0 −1
Original line number Diff line number Diff line
@@ -240,7 +240,6 @@ static void output_pgtable_bits_defines(void) 
	pr_define("_PAGE_MODIFIED_SHIFT %d\n", _PAGE_MODIFIED_SHIFT);

#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT

	pr_define("_PAGE_HUGE_SHIFT %d\n", _PAGE_HUGE_SHIFT);

	pr_define("_PAGE_SPLITTING_SHIFT %d\n", _PAGE_SPLITTING_SHIFT);

#endif

#ifdef CONFIG_CPU_MIPSR2

	if (cpu_has_rixi) {

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