pgtable.h

来自「Linux Kernel 2.6.9 for OMAP1710」· C头文件 代码 · 共 803 行 · 第 1/2 页

	/* A pte is neither clean nor dirty on s/390. The dirty bit
	 * is in the storage key. See page_test_and_clear_dirty for
	 * details.
	 */
	return 0;
}

extern inline int pte_young(pte_t pte)
{
	/* A pte is neither young nor old on s/390. The young bit
	 * is in the storage key. See page_test_and_clear_young for
	 * details.
	 */
	return 0;
}

/*
 * pgd/pmd/pte modification functions
 */

#ifndef __s390x__

extern inline void pgd_clear(pgd_t * pgdp)      { }

extern inline void pmd_clear(pmd_t * pmdp)
{
	pmd_val(pmdp[0]) = _PAGE_TABLE_INV;
	pmd_val(pmdp[1]) = _PAGE_TABLE_INV;
	pmd_val(pmdp[2]) = _PAGE_TABLE_INV;
	pmd_val(pmdp[3]) = _PAGE_TABLE_INV;
}

#else /* __s390x__ */

extern inline void pgd_clear(pgd_t * pgdp)
{
	pgd_val(*pgdp) = _PGD_ENTRY_INV | _PGD_ENTRY;
}

extern inline void pmd_clear(pmd_t * pmdp)
{
	pmd_val(*pmdp) = _PMD_ENTRY_INV | _PMD_ENTRY;
	pmd_val1(*pmdp) = _PMD_ENTRY_INV | _PMD_ENTRY;
}

#endif /* __s390x__ */

extern inline void pte_clear(pte_t *ptep)
{
	pte_val(*ptep) = _PAGE_INVALID_EMPTY;
}

/*
 * The following pte modification functions only work if
 * pte_present() is true. Undefined behaviour if not..
 */
extern inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
	pte_val(pte) &= PAGE_MASK;
	pte_val(pte) |= pgprot_val(newprot);
	return pte;
}

extern inline pte_t pte_wrprotect(pte_t pte)
{
	/* Do not clobber _PAGE_INVALID_NONE pages!  */
	if (!(pte_val(pte) & _PAGE_INVALID))
		pte_val(pte) |= _PAGE_RO;
	return pte;
}

extern inline pte_t pte_mkwrite(pte_t pte) 
{
	pte_val(pte) &= ~_PAGE_RO;
	return pte;
}

extern inline pte_t pte_mkclean(pte_t pte)
{
	/* The only user of pte_mkclean is the fork() code.
	   We must *not* clear the *physical* page dirty bit
	   just because fork() wants to clear the dirty bit in
	   *one* of the page's mappings.  So we just do nothing. */
	return pte;
}

extern inline pte_t pte_mkdirty(pte_t pte)
{
	/* We do not explicitly set the dirty bit because the
	 * sske instruction is slow. It is faster to let the
	 * next instruction set the dirty bit.
	 */
	return pte;
}

extern inline pte_t pte_mkold(pte_t pte)
{
	/* S/390 doesn't keep its dirty/referenced bit in the pte.
	 * There is no point in clearing the real referenced bit.
	 */
	return pte;
}

extern inline pte_t pte_mkyoung(pte_t pte)
{
	/* S/390 doesn't keep its dirty/referenced bit in the pte.
	 * There is no point in setting the real referenced bit.
	 */
	return pte;
}

static inline int ptep_test_and_clear_young(pte_t *ptep)
{
	return 0;
}

static inline int
ptep_clear_flush_young(struct vm_area_struct *vma,
			unsigned long address, pte_t *ptep)
{
	/* No need to flush TLB; bits are in storage key */
	return ptep_test_and_clear_young(ptep);
}

static inline int ptep_test_and_clear_dirty(pte_t *ptep)
{
	return 0;
}

static inline int
ptep_clear_flush_dirty(struct vm_area_struct *vma,
			unsigned long address, pte_t *ptep)
{
	/* No need to flush TLB; bits are in storage key */
	return ptep_test_and_clear_dirty(ptep);
}

static inline pte_t ptep_get_and_clear(pte_t *ptep)
{
	pte_t pte = *ptep;
	pte_clear(ptep);
	return pte;
}

static inline pte_t
ptep_clear_flush(struct vm_area_struct *vma,
		 unsigned long address, pte_t *ptep)
{
	pte_t pte = *ptep;
#ifndef __s390x__
	if (!(pte_val(pte) & _PAGE_INVALID)) {
		/* S390 has 1mb segments, we are emulating 4MB segments */
		pte_t *pto = (pte_t *) (((unsigned long) ptep) & 0x7ffffc00);
		__asm__ __volatile__ ("ipte %2,%3"
				      : "=m" (*ptep) : "m" (*ptep),
				        "a" (pto), "a" (address) );
	}
#else /* __s390x__ */
	if (!(pte_val(pte) & _PAGE_INVALID)) 
		__asm__ __volatile__ ("ipte %2,%3"
				      : "=m" (*ptep) : "m" (*ptep),
				        "a" (ptep), "a" (address) );
#endif /* __s390x__ */
	pte_clear(ptep);
	return pte;
}

static inline void ptep_set_wrprotect(pte_t *ptep)
{
	pte_t old_pte = *ptep;
	set_pte(ptep, pte_wrprotect(old_pte));
}

static inline void ptep_mkdirty(pte_t *ptep)
{
	pte_mkdirty(*ptep);
}

static inline void
ptep_establish(struct vm_area_struct *vma, 
	       unsigned long address, pte_t *ptep,
	       pte_t entry)
{
	ptep_clear_flush(vma, address, ptep);
	set_pte(ptep, entry);
}

#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
	ptep_establish(__vma, __address, __ptep, __entry)

/*
 * Test and clear dirty bit in storage key.
 * We can't clear the changed bit atomically. This is a potential
 * race against modification of the referenced bit. This function
 * should therefore only be called if it is not mapped in any
 * address space.
 */
#define page_test_and_clear_dirty(_page)				  \
({									  \
	struct page *__page = (_page);					  \
	unsigned long __physpage = __pa((__page-mem_map) << PAGE_SHIFT);  \
	int __skey = page_get_storage_key(__physpage);			  \
	if (__skey & _PAGE_CHANGED)					  \
		page_set_storage_key(__physpage, __skey & ~_PAGE_CHANGED);\
	(__skey & _PAGE_CHANGED);					  \
})

/*
 * Test and clear referenced bit in storage key.
 */
#define page_test_and_clear_young(page)					  \
({									  \
	struct page *__page = (page);					  \
	unsigned long __physpage = __pa((__page-mem_map) << PAGE_SHIFT);  \
	int __ccode;							  \
	asm volatile ("rrbe 0,%1\n\t"					  \
		      "ipm  %0\n\t"					  \
		      "srl  %0,28\n\t" 					  \
                      : "=d" (__ccode) : "a" (__physpage) : "cc" );	  \
	(__ccode & 2);							  \
})

/*
 * Conversion functions: convert a page and protection to a page entry,
 * and a page entry and page directory to the page they refer to.
 */
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;
}

#define mk_pte(pg, pgprot)                                                \
({                                                                        \
	struct page *__page = (pg);                                       \
	pgprot_t __pgprot = (pgprot);					  \
	unsigned long __physpage = __pa((__page-mem_map) << PAGE_SHIFT);  \
	pte_t __pte = mk_pte_phys(__physpage, __pgprot);                  \
	__pte;                                                            \
})

#define pfn_pte(pfn, pgprot)                                              \
({                                                                        \
	pgprot_t __pgprot = (pgprot);					  \
	unsigned long __physpage = __pa((pfn) << PAGE_SHIFT);             \
	pte_t __pte = mk_pte_phys(__physpage, __pgprot);                  \
	__pte;                                                            \
})

#define SetPageUptodate(_page) \
	do {								      \
		struct page *__page = (_page);				      \
		if (!test_and_set_bit(PG_uptodate, &__page->flags))	      \
			page_test_and_clear_dirty(_page);		      \
	} while (0)

#ifdef __s390x__

#define pfn_pmd(pfn, pgprot)                                              \
({                                                                        \
	pgprot_t __pgprot = (pgprot);                                     \
	unsigned long __physpage = __pa((pfn) << PAGE_SHIFT);             \
	pmd_t __pmd = __pmd(__physpage + pgprot_val(__pgprot));           \
	__pmd;                                                            \
})

#endif /* __s390x__ */

#define pte_pfn(x) (pte_val(x) >> PAGE_SHIFT)
#define pte_page(x) pfn_to_page(pte_pfn(x))

#define pmd_page_kernel(pmd) (pmd_val(pmd) & PAGE_MASK)

#define pmd_page(pmd) (mem_map+(pmd_val(pmd) >> PAGE_SHIFT))

#define pgd_page_kernel(pgd) (pgd_val(pgd) & PAGE_MASK)

/* 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))

/* to find an entry in a kernel page-table-directory */
#define pgd_offset_k(address) pgd_offset(&init_mm, address)

#ifndef __s390x__

/* Find an entry in the second-level page table.. */
extern inline pmd_t * pmd_offset(pgd_t * dir, unsigned long address)
{
        return (pmd_t *) dir;
}

#else /* __s390x__ */

/* Find an entry in the second-level page table.. */
#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
#define pmd_offset(dir,addr) \
	((pmd_t *) pgd_page_kernel(*(dir)) + pmd_index(addr))

#endif /* __s390x__ */

/* Find an entry in the third-level page table.. */
#define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE-1))
#define pte_offset_kernel(pmd, address) \
	((pte_t *) pmd_page_kernel(*(pmd)) + pte_index(address))
#define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address)
#define pte_offset_map_nested(pmd, address) pte_offset_kernel(pmd, address)
#define pte_unmap(pte) do { } while (0)
#define pte_unmap_nested(pte) do { } while (0)

/*
 * 31 bit swap entry format:
 * A page-table entry has some bits we have to treat in a special way.
 * Bits 0, 20 and bit 23 have to be zero, otherwise an specification
 * exception will occur instead of a page translation exception. The
 * specifiation exception has the bad habit not to store necessary
 * information in the lowcore.
 * Bit 21 and bit 22 are the page invalid bit and the page protection
 * bit. We set both to indicate a swapped page.
 * Bit 30 and 31 are used to distinguish the different page types. For
 * a swapped page these bits need to be zero.
 * This leaves the bits 1-19 and bits 24-29 to store type and offset.
 * We use the 5 bits from 25-29 for the type and the 20 bits from 1-19
 * plus 24 for the offset.
 * 0|     offset        |0110|o|type |00|
 * 0 0000000001111111111 2222 2 22222 33
 * 0 1234567890123456789 0123 4 56789 01
 *
 * 64 bit swap entry format:
 * A page-table entry has some bits we have to treat in a special way.
 * Bits 52 and bit 55 have to be zero, otherwise an specification
 * exception will occur instead of a page translation exception. The
 * specifiation exception has the bad habit not to store necessary
 * information in the lowcore.
 * Bit 53 and bit 54 are the page invalid bit and the page protection
 * bit. We set both to indicate a swapped page.
 * Bit 62 and 63 are used to distinguish the different page types. For
 * a swapped page these bits need to be zero.
 * This leaves the bits 0-51 and bits 56-61 to store type and offset.
 * We use the 5 bits from 57-61 for the type and the 53 bits from 0-51
 * plus 56 for the offset.
 * |                      offset                        |0110|o|type |00|
 *  0000000000111111111122222222223333333333444444444455 5555 5 55566 66
 *  0123456789012345678901234567890123456789012345678901 2345 6 78901 23
 */
extern inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
{
	pte_t pte;
	pte_val(pte) = _PAGE_INVALID_SWAP | ((type & 0x1f) << 2) |
		((offset & 1) << 7) | ((offset & 0xffffe) << 11);
	return pte;
}

#define __swp_type(entry)	(((entry).val >> 2) & 0x1f)
#define __swp_offset(entry)	(((entry).val >> 11) | (((entry).val >> 7) & 1))
#define __swp_entry(type,offset) ((swp_entry_t) { pte_val(mk_swap_pte((type),(offset))) })

#define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
#define __swp_entry_to_pte(x)	((pte_t) { (x).val })

#ifndef __s390x__
# define PTE_FILE_MAX_BITS	26
#else /* __s390x__ */
# define PTE_FILE_MAX_BITS	59
#endif /* __s390x__ */

#define pte_to_pgoff(__pte) \
	((((__pte).pte >> 12) << 7) + (((__pte).pte >> 1) & 0x7f))

#define pgoff_to_pte(__off) \
	((pte_t) { ((((__off) & 0x7f) << 1) + (((__off) >> 7) << 12)) \
		   | _PAGE_INVALID_FILE })

#endif /* !__ASSEMBLY__ */

#define kern_addr_valid(addr)   (1)

/*
 * No page table caches to initialise
 */
#define pgtable_cache_init()	do { } while (0)

#define __HAVE_ARCH_PTEP_ESTABLISH
#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
#define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
#define __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
#define __HAVE_ARCH_PTEP_CLEAR_FLUSH
#define __HAVE_ARCH_PTEP_SET_WRPROTECT
#define __HAVE_ARCH_PTEP_MKDIRTY
#define __HAVE_ARCH_PTE_SAME
#define __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
#define __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
#include <asm-generic/pgtable.h>

#endif /* _S390_PAGE_H */