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Commit 5614dd92 authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390/mm: implement soft-dirty bits for user memory change tracking 



Use bit 2**1 of the pte and bit 2**14 of the pmd for the soft dirty
bit. The fault mechanism to do dirty tracking is already in place.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent a7b76174

arch/s390/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -118,6 +118,7 @@ config S390 
	select HAVE_ARCH_EARLY_PFN_TO_NID

	select HAVE_ARCH_JUMP_LABEL

	select HAVE_ARCH_SECCOMP_FILTER

	select HAVE_ARCH_SOFT_DIRTY

	select HAVE_ARCH_TRACEHOOK

	select HAVE_ARCH_TRANSPARENT_HUGEPAGE

	select HAVE_BPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES

arch/s390/include/asm/pgtable.h

+55 −4
Original line number Diff line number Diff line
@@ -193,9 +193,15 @@ static inline int is_module_addr(void *addr) 
#define _PAGE_UNUSED	0x080		/* SW bit for pgste usage state */

#define __HAVE_ARCH_PTE_SPECIAL



#ifdef CONFIG_MEM_SOFT_DIRTY

#define _PAGE_SOFT_DIRTY 0x002		/* SW pte soft dirty bit */

#else

#define _PAGE_SOFT_DIRTY 0x000

#endif



/* Set of bits not changed in pte_modify */

#define _PAGE_CHG_MASK		(PAGE_MASK | _PAGE_SPECIAL | _PAGE_DIRTY | \

				 _PAGE_YOUNG)

				 _PAGE_YOUNG | _PAGE_SOFT_DIRTY)



/*

 * handle_pte_fault uses pte_present and pte_none to find out the pte type
@@ -285,6 +291,12 @@ static inline int is_module_addr(void *addr) 
#define _SEGMENT_ENTRY_READ	0x0002	/* SW segment read bit */

#define _SEGMENT_ENTRY_WRITE	0x0001	/* SW segment write bit */



#ifdef CONFIG_MEM_SOFT_DIRTY

#define _SEGMENT_ENTRY_SOFT_DIRTY 0x4000 /* SW segment soft dirty bit */

#else

#define _SEGMENT_ENTRY_SOFT_DIRTY 0x0000 /* SW segment soft dirty bit */

#endif



/*

 * Segment table entry encoding (R = read-only, I = invalid, y = young bit):

 *				dy..R...I...wr
@@ -589,6 +601,43 @@ static inline int pmd_protnone(pmd_t pmd) 
}

#endif



static inline int pte_soft_dirty(pte_t pte)

{

	return pte_val(pte) & _PAGE_SOFT_DIRTY;

}

#define pte_swp_soft_dirty pte_soft_dirty



static inline pte_t pte_mksoft_dirty(pte_t pte)

{

	pte_val(pte) |= _PAGE_SOFT_DIRTY;

	return pte;

}

#define pte_swp_mksoft_dirty pte_mksoft_dirty



static inline pte_t pte_clear_soft_dirty(pte_t pte)

{

	pte_val(pte) &= ~_PAGE_SOFT_DIRTY;

	return pte;

}

#define pte_swp_clear_soft_dirty pte_clear_soft_dirty



static inline int pmd_soft_dirty(pmd_t pmd)

{

	return pmd_val(pmd) & _SEGMENT_ENTRY_SOFT_DIRTY;

}



static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)

{

	pmd_val(pmd) |= _SEGMENT_ENTRY_SOFT_DIRTY;

	return pmd;

}



static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)

{

	pmd_val(pmd) &= ~_SEGMENT_ENTRY_SOFT_DIRTY;

	return pmd;

}



static inline pgste_t pgste_get_lock(pte_t *ptep)

{

	unsigned long new = 0;
@@ -889,7 +938,7 @@ static inline pte_t pte_mkclean(pte_t pte) 


static inline pte_t pte_mkdirty(pte_t pte)

{

	pte_val(pte) |= _PAGE_DIRTY;

	pte_val(pte) |= _PAGE_DIRTY | _PAGE_SOFT_DIRTY;

	if (pte_val(pte) & _PAGE_WRITE)

		pte_val(pte) &= ~_PAGE_PROTECT;

	return pte;
@@ -1340,7 +1389,8 @@ static inline pmd_t pmd_mkclean(pmd_t pmd) 
static inline pmd_t pmd_mkdirty(pmd_t pmd)

{

	if (pmd_large(pmd)) {

		pmd_val(pmd) |= _SEGMENT_ENTRY_DIRTY;

		pmd_val(pmd) |= _SEGMENT_ENTRY_DIRTY |

				_SEGMENT_ENTRY_SOFT_DIRTY;

		if (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE)

			pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT;

	}
@@ -1371,7 +1421,8 @@ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) 
	if (pmd_large(pmd)) {

		pmd_val(pmd) &= _SEGMENT_ENTRY_ORIGIN_LARGE |

			_SEGMENT_ENTRY_DIRTY | _SEGMENT_ENTRY_YOUNG |

			_SEGMENT_ENTRY_LARGE | _SEGMENT_ENTRY_SPLIT;

			_SEGMENT_ENTRY_LARGE | _SEGMENT_ENTRY_SPLIT |

			_SEGMENT_ENTRY_SOFT_DIRTY;

		pmd_val(pmd) |= massage_pgprot_pmd(newprot);

		if (!(pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY))

			pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;

arch/s390/mm/hugetlbpage.c

+2 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ static inline pmd_t __pte_to_pmd(pte_t pte) 
		pmd_val(pmd) |= (pte_val(pte) & _PAGE_PROTECT);

		pmd_val(pmd) |= (pte_val(pte) & _PAGE_DIRTY) << 10;

		pmd_val(pmd) |= (pte_val(pte) & _PAGE_YOUNG) << 10;

		pmd_val(pmd) |= (pte_val(pte) & _PAGE_SOFT_DIRTY) << 13;

	} else

		pmd_val(pmd) = _SEGMENT_ENTRY_INVALID;

	return pmd;
@@ -78,6 +79,7 @@ static inline pte_t __pmd_to_pte(pmd_t pmd) 
		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT);

		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY) >> 10;

		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) >> 10;

		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_SOFT_DIRTY) >> 13;

	} else

		pte_val(pte) = _PAGE_INVALID;

	return pte;