diff options
Diffstat (limited to 'arch/s390/include/asm/pgtable.h')
-rw-r--r-- | arch/s390/include/asm/pgtable.h | 345 |
1 files changed, 197 insertions, 148 deletions
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 1d144b6f3ba2..9f215b40109e 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -226,8 +226,9 @@ extern unsigned long MODULES_END; #define _PAGE_TYPE 0x002 /* SW pte type bit */ #define _PAGE_YOUNG 0x004 /* SW pte young bit */ #define _PAGE_DIRTY 0x008 /* SW pte dirty bit */ -#define _PAGE_WRITE 0x010 /* SW pte write bit */ -#define _PAGE_SPECIAL 0x020 /* SW associated with special page */ +#define _PAGE_READ 0x010 /* SW pte read bit */ +#define _PAGE_WRITE 0x020 /* SW pte write bit */ +#define _PAGE_SPECIAL 0x040 /* SW associated with special page */ #define __HAVE_ARCH_PTE_SPECIAL /* Set of bits not changed in pte_modify */ @@ -243,19 +244,25 @@ extern unsigned long MODULES_END; * The following table gives the different possible bit combinations for * the pte hardware and software bits in the last 12 bits of a pte: * - * 842100000000 - * 000084210000 - * 000000008421 - * .IR....wdytp - * empty .10....00000 - * swap .10....xxx10 - * file .11....xxxx0 - * prot-none, clean .11....00x01 - * prot-none, dirty .10....01x01 - * read-only, clean .01....00x01 - * read-only, dirty .01....01x01 - * read-write, clean .01....10x01 - * read-write, dirty .00....11x01 + * 842100000000 + * 000084210000 + * 000000008421 + * .IR...wrdytp + * empty .10...000000 + * swap .10...xxxx10 + * file .11...xxxxx0 + * prot-none, clean, old .11...000001 + * prot-none, clean, young .11...000101 + * prot-none, dirty, old .10...001001 + * prot-none, dirty, young .10...001101 + * read-only, clean, old .11...010001 + * read-only, clean, young .01...010101 + * read-only, dirty, old .11...011001 + * read-only, dirty, young .01...011101 + * read-write, clean, old .11...110001 + * read-write, clean, young .01...110101 + * read-write, dirty, old .10...111001 + * read-write, dirty, young .00...111101 * * pte_present is true for the bit pattern .xx...xxxxx1, (pte & 0x001) == 0x001 * pte_none is true for the bit pattern .10...xxxx00, (pte & 0x603) == 0x400 @@ -273,15 +280,26 @@ extern unsigned long MODULES_END; #define _ASCE_TABLE_LENGTH 0x7f /* 128 x 64 entries = 8k */ /* Bits in the segment table entry */ +#define _SEGMENT_ENTRY_BITS 0x7fffffffUL /* Valid segment table bits */ #define _SEGMENT_ENTRY_ORIGIN 0x7fffffc0UL /* page table origin */ #define _SEGMENT_ENTRY_PROTECT 0x200 /* page protection bit */ #define _SEGMENT_ENTRY_INVALID 0x20 /* invalid segment table entry */ #define _SEGMENT_ENTRY_COMMON 0x10 /* common segment bit */ #define _SEGMENT_ENTRY_PTL 0x0f /* page table length */ +#define _SEGMENT_ENTRY_NONE _SEGMENT_ENTRY_PROTECT #define _SEGMENT_ENTRY (_SEGMENT_ENTRY_PTL) #define _SEGMENT_ENTRY_EMPTY (_SEGMENT_ENTRY_INVALID) +/* + * Segment table entry encoding (I = invalid, R = read-only bit): + * ..R...I..... + * prot-none ..1...1..... + * read-only ..1...0..... + * read-write ..0...0..... + * empty ..0...1..... + */ + /* Page status table bits for virtualization */ #define PGSTE_ACC_BITS 0xf0000000UL #define PGSTE_FP_BIT 0x08000000UL @@ -290,9 +308,7 @@ extern unsigned long MODULES_END; #define PGSTE_HC_BIT 0x00200000UL #define PGSTE_GR_BIT 0x00040000UL #define PGSTE_GC_BIT 0x00020000UL -#define PGSTE_UR_BIT 0x00008000UL -#define PGSTE_UC_BIT 0x00004000UL /* user dirty (migration) */ -#define PGSTE_IN_BIT 0x00002000UL /* IPTE notify bit */ +#define PGSTE_IN_BIT 0x00008000UL /* IPTE notify bit */ #else /* CONFIG_64BIT */ @@ -331,6 +347,8 @@ extern unsigned long MODULES_END; #define _REGION3_ENTRY_CO 0x100 /* change-recording override */ /* Bits in the segment table entry */ +#define _SEGMENT_ENTRY_BITS 0xfffffffffffffe33UL +#define _SEGMENT_ENTRY_BITS_LARGE 0xfffffffffff1ff33UL #define _SEGMENT_ENTRY_ORIGIN_LARGE ~0xfffffUL /* large page address */ #define _SEGMENT_ENTRY_ORIGIN ~0x7ffUL/* segment table origin */ #define _SEGMENT_ENTRY_PROTECT 0x200 /* page protection bit */ @@ -342,6 +360,21 @@ extern unsigned long MODULES_END; #define _SEGMENT_ENTRY_LARGE 0x400 /* STE-format control, large page */ #define _SEGMENT_ENTRY_CO 0x100 /* change-recording override */ #define _SEGMENT_ENTRY_SPLIT 0x001 /* THP splitting bit */ +#define _SEGMENT_ENTRY_YOUNG 0x002 /* SW segment young bit */ +#define _SEGMENT_ENTRY_NONE _SEGMENT_ENTRY_YOUNG + +/* + * Segment table entry encoding (R = read-only, I = invalid, y = young bit): + * ..R...I...y. + * prot-none, old ..0...1...1. + * prot-none, young ..1...1...1. + * read-only, old ..1...1...0. + * read-only, young ..1...0...1. + * read-write, old ..0...1...0. + * read-write, young ..0...0...1. + * The segment table origin is used to distinguish empty (origin==0) from + * read-write, old segment table entries (origin!=0) + */ #define _SEGMENT_ENTRY_SPLIT_BIT 0 /* THP splitting bit number */ @@ -357,9 +390,7 @@ extern unsigned long MODULES_END; #define PGSTE_HC_BIT 0x0020000000000000UL #define PGSTE_GR_BIT 0x0004000000000000UL #define PGSTE_GC_BIT 0x0002000000000000UL -#define PGSTE_UR_BIT 0x0000800000000000UL -#define PGSTE_UC_BIT 0x0000400000000000UL /* user dirty (migration) */ -#define PGSTE_IN_BIT 0x0000200000000000UL /* IPTE notify bit */ +#define PGSTE_IN_BIT 0x0000800000000000UL /* IPTE notify bit */ #endif /* CONFIG_64BIT */ @@ -375,12 +406,17 @@ extern unsigned long MODULES_END; * Page protection definitions. */ #define PAGE_NONE __pgprot(_PAGE_PRESENT | _PAGE_INVALID) -#define PAGE_READ __pgprot(_PAGE_PRESENT | _PAGE_PROTECT) -#define PAGE_WRITE __pgprot(_PAGE_PRESENT | _PAGE_WRITE | _PAGE_PROTECT) - -#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_WRITE | _PAGE_DIRTY) -#define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_WRITE | _PAGE_DIRTY) -#define PAGE_KERNEL_RO __pgprot(_PAGE_PRESENT | _PAGE_PROTECT) +#define PAGE_READ __pgprot(_PAGE_PRESENT | _PAGE_READ | \ + _PAGE_INVALID | _PAGE_PROTECT) +#define PAGE_WRITE __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \ + _PAGE_INVALID | _PAGE_PROTECT) + +#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \ + _PAGE_YOUNG | _PAGE_DIRTY) +#define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \ + _PAGE_YOUNG | _PAGE_DIRTY) +#define PAGE_KERNEL_RO __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_YOUNG | \ + _PAGE_PROTECT) /* * On s390 the page table entry has an invalid bit and a read-only bit. @@ -410,9 +446,10 @@ extern unsigned long MODULES_END; * Segment entry (large page) protection definitions. */ #define SEGMENT_NONE __pgprot(_SEGMENT_ENTRY_INVALID | \ + _SEGMENT_ENTRY_NONE) +#define SEGMENT_READ __pgprot(_SEGMENT_ENTRY_INVALID | \ _SEGMENT_ENTRY_PROTECT) -#define SEGMENT_READ __pgprot(_SEGMENT_ENTRY_PROTECT) -#define SEGMENT_WRITE __pgprot(0) +#define SEGMENT_WRITE __pgprot(_SEGMENT_ENTRY_INVALID) static inline int mm_has_pgste(struct mm_struct *mm) { @@ -520,10 +557,19 @@ static inline int pmd_large(pmd_t pmd) #endif } +static inline int pmd_prot_none(pmd_t pmd) +{ + return (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) && + (pmd_val(pmd) & _SEGMENT_ENTRY_NONE); +} + static inline int pmd_bad(pmd_t pmd) { - unsigned long mask = ~_SEGMENT_ENTRY_ORIGIN & ~_SEGMENT_ENTRY_INVALID; - return (pmd_val(pmd) & mask) != _SEGMENT_ENTRY; +#ifdef CONFIG_64BIT + if (pmd_large(pmd)) + return (pmd_val(pmd) & ~_SEGMENT_ENTRY_BITS_LARGE) != 0; +#endif + return (pmd_val(pmd) & ~_SEGMENT_ENTRY_BITS) != 0; } #define __HAVE_ARCH_PMDP_SPLITTING_FLUSH @@ -542,12 +588,21 @@ extern int pmdp_clear_flush_young(struct vm_area_struct *vma, #define __HAVE_ARCH_PMD_WRITE static inline int pmd_write(pmd_t pmd) { + if (pmd_prot_none(pmd)) + return 0; return (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT) == 0; } static inline int pmd_young(pmd_t pmd) { - return 0; + int young = 0; +#ifdef CONFIG_64BIT + if (pmd_prot_none(pmd)) + young = (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT) != 0; + else + young = (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) != 0; +#endif + return young; } static inline int pte_present(pte_t pte) @@ -632,33 +687,28 @@ static inline void pgste_set(pte_t *ptep, pgste_t pgste) static inline pgste_t pgste_update_all(pte_t *ptep, pgste_t pgste) { #ifdef CONFIG_PGSTE - unsigned long address, bits; - unsigned char skey; + unsigned long address, bits, skey; if (pte_val(*ptep) & _PAGE_INVALID) return pgste; address = pte_val(*ptep) & PAGE_MASK; - skey = page_get_storage_key(address); + skey = (unsigned long) page_get_storage_key(address); bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED); - /* Clear page changed & referenced bit in the storage key */ - if (bits & _PAGE_CHANGED) + if (!(pgste_val(pgste) & PGSTE_HC_BIT) && (bits & _PAGE_CHANGED)) { + /* Transfer dirty + referenced bit to host bits in pgste */ + pgste_val(pgste) |= bits << 52; page_set_storage_key(address, skey ^ bits, 0); - else if (bits) + } else if (!(pgste_val(pgste) & PGSTE_HR_BIT) && + (bits & _PAGE_REFERENCED)) { + /* Transfer referenced bit to host bit in pgste */ + pgste_val(pgste) |= PGSTE_HR_BIT; page_reset_referenced(address); + } /* Transfer page changed & referenced bit to guest bits in pgste */ pgste_val(pgste) |= bits << 48; /* GR bit & GC bit */ - /* Get host changed & referenced bits from pgste */ - bits |= (pgste_val(pgste) & (PGSTE_HR_BIT | PGSTE_HC_BIT)) >> 52; - /* Transfer page changed & referenced bit to kvm user bits */ - pgste_val(pgste) |= bits << 45; /* PGSTE_UR_BIT & PGSTE_UC_BIT */ - /* Clear relevant host bits in pgste. */ - pgste_val(pgste) &= ~(PGSTE_HR_BIT | PGSTE_HC_BIT); - pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT); /* Copy page access key and fetch protection bit to pgste */ - pgste_val(pgste) |= - (unsigned long) (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56; - /* Transfer referenced bit to pte */ - pte_val(*ptep) |= (bits & _PAGE_REFERENCED) << 1; + pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT); + pgste_val(pgste) |= (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56; #endif return pgste; @@ -667,24 +717,11 @@ static inline pgste_t pgste_update_all(pte_t *ptep, pgste_t pgste) static inline pgste_t pgste_update_young(pte_t *ptep, pgste_t pgste) { #ifdef CONFIG_PGSTE - int young; - if (pte_val(*ptep) & _PAGE_INVALID) return pgste; /* Get referenced bit from storage key */ - young = page_reset_referenced(pte_val(*ptep) & PAGE_MASK); - if (young) - pgste_val(pgste) |= PGSTE_GR_BIT; - /* Get host referenced bit from pgste */ - if (pgste_val(pgste) & PGSTE_HR_BIT) { - pgste_val(pgste) &= ~PGSTE_HR_BIT; - young = 1; - } - /* Transfer referenced bit to kvm user bits and pte */ - if (young) { - pgste_val(pgste) |= PGSTE_UR_BIT; - pte_val(*ptep) |= _PAGE_YOUNG; - } + if (page_reset_referenced(pte_val(*ptep) & PAGE_MASK)) + pgste_val(pgste) |= PGSTE_HR_BIT | PGSTE_GR_BIT; #endif return pgste; } @@ -839,11 +876,7 @@ static inline int pte_dirty(pte_t pte) static inline int pte_young(pte_t pte) { -#ifdef CONFIG_PGSTE - if (pte_val(pte) & _PAGE_YOUNG) - return 1; -#endif - return 0; + return (pte_val(pte) & _PAGE_YOUNG) != 0; } /* @@ -884,6 +917,16 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { pte_val(pte) &= _PAGE_CHG_MASK; pte_val(pte) |= pgprot_val(newprot); + /* + * newprot for PAGE_NONE, PAGE_READ and PAGE_WRITE has the + * invalid bit set, clear it again for readable, young pages + */ + if ((pte_val(pte) & _PAGE_YOUNG) && (pte_val(pte) & _PAGE_READ)) + pte_val(pte) &= ~_PAGE_INVALID; + /* + * newprot for PAGE_READ and PAGE_WRITE has the page protection + * bit set, clear it again for writable, dirty pages + */ if ((pte_val(pte) & _PAGE_DIRTY) && (pte_val(pte) & _PAGE_WRITE)) pte_val(pte) &= ~_PAGE_PROTECT; return pte; @@ -921,14 +964,16 @@ static inline pte_t pte_mkdirty(pte_t pte) static inline pte_t pte_mkold(pte_t pte) { -#ifdef CONFIG_PGSTE pte_val(pte) &= ~_PAGE_YOUNG; -#endif + pte_val(pte) |= _PAGE_INVALID; return pte; } static inline pte_t pte_mkyoung(pte_t pte) { + pte_val(pte) |= _PAGE_YOUNG; + if (pte_val(pte) & _PAGE_READ) + pte_val(pte) &= ~_PAGE_INVALID; return pte; } @@ -958,8 +1003,8 @@ static inline int ptep_test_and_clear_user_dirty(struct mm_struct *mm, if (mm_has_pgste(mm)) { pgste = pgste_get_lock(ptep); pgste = pgste_update_all(ptep, pgste); - dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT); - pgste_val(pgste) &= ~PGSTE_UC_BIT; + dirty = !!(pgste_val(pgste) & PGSTE_HC_BIT); + pgste_val(pgste) &= ~PGSTE_HC_BIT; pgste_set_unlock(ptep, pgste); return dirty; } @@ -978,42 +1023,13 @@ static inline int ptep_test_and_clear_user_young(struct mm_struct *mm, if (mm_has_pgste(mm)) { pgste = pgste_get_lock(ptep); pgste = pgste_update_young(ptep, pgste); - young = !!(pgste_val(pgste) & PGSTE_UR_BIT); - pgste_val(pgste) &= ~PGSTE_UR_BIT; + young = !!(pgste_val(pgste) & PGSTE_HR_BIT); + pgste_val(pgste) &= ~PGSTE_HR_BIT; pgste_set_unlock(ptep, pgste); } return young; } -#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG -static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) -{ - pgste_t pgste; - pte_t pte; - - if (mm_has_pgste(vma->vm_mm)) { - pgste = pgste_get_lock(ptep); - pgste = pgste_update_young(ptep, pgste); - pte = *ptep; - *ptep = pte_mkold(pte); - pgste_set_unlock(ptep, pgste); - return pte_young(pte); - } - return 0; -} - -#define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH -static inline int ptep_clear_flush_young(struct vm_area_struct *vma, - unsigned long address, pte_t *ptep) -{ - /* No need to flush TLB - * On s390 reference bits are in storage key and never in TLB - * With virtualization we handle the reference bit, without we - * we can simply return */ - return ptep_test_and_clear_young(vma, address, ptep); -} - static inline void __ptep_ipte(unsigned long address, pte_t *ptep) { if (!(pte_val(*ptep) & _PAGE_INVALID)) { @@ -1042,6 +1058,40 @@ static inline void ptep_flush_lazy(struct mm_struct *mm, mm->context.flush_mm = 1; } +#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG +static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) +{ + pgste_t pgste; + pte_t pte; + int young; + + if (mm_has_pgste(vma->vm_mm)) { + pgste = pgste_get_lock(ptep); + pgste = pgste_ipte_notify(vma->vm_mm, addr, ptep, pgste); + } + + pte = *ptep; + __ptep_ipte(addr, ptep); + young = pte_young(pte); + pte = pte_mkold(pte); + + if (mm_has_pgste(vma->vm_mm)) { + pgste_set_pte(ptep, pte); + pgste_set_unlock(ptep, pgste); + } else + *ptep = pte; + + return young; +} + +#define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH +static inline int ptep_clear_flush_young(struct vm_area_struct *vma, + unsigned long address, pte_t *ptep) +{ + return ptep_test_and_clear_young(vma, address, ptep); +} + /* * This is hard to understand. ptep_get_and_clear and ptep_clear_flush * both clear the TLB for the unmapped pte. The reason is that @@ -1229,7 +1279,7 @@ static inline pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot) { pte_t __pte; pte_val(__pte) = physpage + pgprot_val(pgprot); - return __pte; + return pte_mkyoung(__pte); } static inline pte_t mk_pte(struct page *page, pgprot_t pgprot) @@ -1338,10 +1388,41 @@ static inline unsigned long massage_pgprot_pmd(pgprot_t pgprot) return pgprot_val(SEGMENT_WRITE); } +static inline pmd_t pmd_mkyoung(pmd_t pmd) +{ +#ifdef CONFIG_64BIT + if (pmd_prot_none(pmd)) { + pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT; + } else { + pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG; + pmd_val(pmd) &= ~_SEGMENT_ENTRY_INVALID; + } +#endif + return pmd; +} + +static inline pmd_t pmd_mkold(pmd_t pmd) +{ +#ifdef CONFIG_64BIT + if (pmd_prot_none(pmd)) { + pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT; + } else { + pmd_val(pmd) &= ~_SEGMENT_ENTRY_YOUNG; + pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID; + } +#endif + return pmd; +} + static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) { + int young; + + young = pmd_young(pmd); pmd_val(pmd) &= _SEGMENT_CHG_MASK; pmd_val(pmd) |= massage_pgprot_pmd(newprot); + if (young) + pmd = pmd_mkyoung(pmd); return pmd; } @@ -1349,13 +1430,13 @@ static inline pmd_t mk_pmd_phys(unsigned long physpage, pgprot_t pgprot) { pmd_t __pmd; pmd_val(__pmd) = physpage + massage_pgprot_pmd(pgprot); - return __pmd; + return pmd_mkyoung(__pmd); } static inline pmd_t pmd_mkwrite(pmd_t pmd) { - /* Do not clobber PROT_NONE pages! */ - if (!(pmd_val(pmd) & _SEGMENT_ENTRY_INVALID)) + /* Do not clobber PROT_NONE segments! */ + if (!pmd_prot_none(pmd)) pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT; return pmd; } @@ -1391,7 +1472,9 @@ static inline pmd_t pmd_mkhuge(pmd_t pmd) static inline pmd_t pmd_wrprotect(pmd_t pmd) { - pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT; + /* Do not clobber PROT_NONE segments! */ + if (!pmd_prot_none(pmd)) + pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT; return pmd; } @@ -1401,50 +1484,16 @@ static inline pmd_t pmd_mkdirty(pmd_t pmd) return pmd; } -static inline pmd_t pmd_mkold(pmd_t pmd) -{ - /* No referenced bit in the segment table entry. */ - return pmd; -} - -static inline pmd_t pmd_mkyoung(pmd_t pmd) -{ - /* No referenced bit in the segment table entry. */ - return pmd; -} - #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp) { - unsigned long pmd_addr = pmd_val(*pmdp) & HPAGE_MASK; - long tmp, rc; - int counter; + pmd_t pmd; - rc = 0; - if (MACHINE_HAS_RRBM) { - counter = PTRS_PER_PTE >> 6; - asm volatile( - "0: .insn rre,0xb9ae0000,%0,%3\n" /* rrbm */ - " ogr %1,%0\n" - " la %3,0(%4,%3)\n" - " brct %2,0b\n" - : "=&d" (tmp), "+&d" (rc), "+d" (counter), - "+a" (pmd_addr) - : "a" (64 * 4096UL) : "cc"); - rc = !!rc; - } else { - counter = PTRS_PER_PTE; - asm volatile( - "0: rrbe 0,%2\n" - " la %2,0(%3,%2)\n" - " brc 12,1f\n" - " lhi %0,1\n" - "1: brct %1,0b\n" - : "+d" (rc), "+d" (counter), "+a" (pmd_addr) - : "a" (4096UL) : "cc"); - } - return rc; + pmd = *pmdp; + __pmd_idte(address, pmdp); + *pmdp = pmd_mkold(pmd); + return pmd_young(pmd); } #define __HAVE_ARCH_PMDP_GET_AND_CLEAR |