pgtable.h

来自「Linux Kernel 2.6.9 for OMAP1710」· C头文件 代码 · 共 738 行 · 第 1/2 页

 * so to write-protect kernel memory we must turn on user access */
#define _PAGE_KERNEL_RO	(_PAGE_BASE | _PAGE_SHARED | _PAGE_USER)
#else
#define _PAGE_KERNEL_RO	(_PAGE_BASE | _PAGE_SHARED)
#endif

#define _PAGE_IO	(_PAGE_KERNEL | _PAGE_NO_CACHE | _PAGE_GUARDED)
#define _PAGE_RAM	(_PAGE_KERNEL | _PAGE_HWEXEC)

#if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH)
/* We want the debuggers to be able to set breakpoints anywhere, so
 * don't write protect the kernel text */
#define _PAGE_RAM_TEXT	_PAGE_RAM
#else
#define _PAGE_RAM_TEXT	(_PAGE_KERNEL_RO | _PAGE_HWEXEC)
#endif

#define PAGE_NONE	__pgprot(_PAGE_BASE)
#define PAGE_READONLY	__pgprot(_PAGE_BASE | _PAGE_USER)
#define PAGE_READONLY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
#define PAGE_SHARED	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
#define PAGE_SHARED_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC)
#define PAGE_COPY	__pgprot(_PAGE_BASE | _PAGE_USER)
#define PAGE_COPY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)

#define PAGE_KERNEL		__pgprot(_PAGE_RAM)
#define PAGE_KERNEL_NOCACHE	__pgprot(_PAGE_IO)

/*
 * The PowerPC can only do execute protection on a segment (256MB) basis,
 * not on a page basis.  So we consider execute permission the same as read.
 * Also, write permissions imply read permissions.
 * This is the closest we can get..
 */
#define __P000	PAGE_NONE
#define __P001	PAGE_READONLY_X
#define __P010	PAGE_COPY
#define __P011	PAGE_COPY_X
#define __P100	PAGE_READONLY
#define __P101	PAGE_READONLY_X
#define __P110	PAGE_COPY
#define __P111	PAGE_COPY_X

#define __S000	PAGE_NONE
#define __S001	PAGE_READONLY_X
#define __S010	PAGE_SHARED
#define __S011	PAGE_SHARED_X
#define __S100	PAGE_READONLY
#define __S101	PAGE_READONLY_X
#define __S110	PAGE_SHARED
#define __S111	PAGE_SHARED_X

#ifndef __ASSEMBLY__
/* Make sure we get a link error if PMD_PAGE_SIZE is ever called on a
 * kernel without large page PMD support */
extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);

/*
 * Conversions between PTE values and page frame numbers.
 */

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

#define pfn_pte(pfn, prot)	__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
#define mk_pte(page, prot)	pfn_pte(page_to_pfn(page), prot)

/*
 * ZERO_PAGE is a global shared page that is always zero: used
 * for zero-mapped memory areas etc..
 */
extern unsigned long empty_zero_page[1024];
#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))

#endif /* __ASSEMBLY__ */

#define pte_none(pte)		((pte_val(pte) & ~_PTE_NONE_MASK) == 0)
#define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
#define pte_clear(ptep)		do { set_pte((ptep), __pte(0)); } while (0)

#define pmd_none(pmd)		(!pmd_val(pmd))
#define	pmd_bad(pmd)		(pmd_val(pmd) & _PMD_BAD)
#define	pmd_present(pmd)	(pmd_val(pmd) & _PMD_PRESENT_MASK)
#define	pmd_clear(pmdp)		do { pmd_val(*(pmdp)) = 0; } while (0)

#ifndef __ASSEMBLY__
/*
 * The "pgd_xxx()" functions here are trivial for a folded two-level
 * setup: the pgd is never bad, and a pmd always exists (as it's folded
 * into the pgd entry)
 */
static inline int pgd_none(pgd_t pgd)		{ return 0; }
static inline int pgd_bad(pgd_t pgd)		{ return 0; }
static inline int pgd_present(pgd_t pgd)	{ return 1; }
#define pgd_clear(xp)				do { } while (0)

#define pgd_page(pgd) \
	((unsigned long) __va(pgd_val(pgd) & PAGE_MASK))

/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */
static inline int pte_read(pte_t pte)		{ return pte_val(pte) & _PAGE_USER; }
static inline int pte_write(pte_t pte)		{ return pte_val(pte) & _PAGE_RW; }
static inline int pte_exec(pte_t pte)		{ return pte_val(pte) & _PAGE_EXEC; }
static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
static inline int pte_file(pte_t pte)		{ return pte_val(pte) & _PAGE_FILE; }

static inline void pte_uncache(pte_t pte)       { pte_val(pte) |= _PAGE_NO_CACHE; }
static inline void pte_cache(pte_t pte)         { pte_val(pte) &= ~_PAGE_NO_CACHE; }

static inline pte_t pte_rdprotect(pte_t pte) {
	pte_val(pte) &= ~_PAGE_USER; return pte; }
static inline pte_t pte_wrprotect(pte_t pte) {
	pte_val(pte) &= ~(_PAGE_RW | _PAGE_HWWRITE); return pte; }
static inline pte_t pte_exprotect(pte_t pte) {
	pte_val(pte) &= ~_PAGE_EXEC; return pte; }
static inline pte_t pte_mkclean(pte_t pte) {
	pte_val(pte) &= ~(_PAGE_DIRTY | _PAGE_HWWRITE); return pte; }
static inline pte_t pte_mkold(pte_t pte) {
	pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }

static inline pte_t pte_mkread(pte_t pte) {
	pte_val(pte) |= _PAGE_USER; return pte; }
static inline pte_t pte_mkexec(pte_t pte) {
	pte_val(pte) |= _PAGE_USER | _PAGE_EXEC; return pte; }
static inline pte_t pte_mkwrite(pte_t pte) {
	pte_val(pte) |= _PAGE_RW; return pte; }
static inline pte_t pte_mkdirty(pte_t pte) {
	pte_val(pte) |= _PAGE_DIRTY; return pte; }
static inline pte_t pte_mkyoung(pte_t pte) {
	pte_val(pte) |= _PAGE_ACCESSED; return pte; }

static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
	pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot);
	return pte;
}

/*
 * Atomic PTE updates.
 *
 * pte_update clears and sets bit atomically, and returns
 * the old pte value.
 * The ((unsigned long)(p+1) - 4) hack is to get to the least-significant
 * 32 bits of the PTE regardless of whether PTEs are 32 or 64 bits.
 */
static inline unsigned long pte_update(pte_t *p, unsigned long clr,
				       unsigned long set)
{
	unsigned long old, tmp;

	__asm__ __volatile__("\
1:	lwarx	%0,0,%3\n\
	andc	%1,%0,%4\n\
	or	%1,%1,%5\n"
	PPC405_ERR77(0,%3)
"	stwcx.	%1,0,%3\n\
	bne-	1b"
	: "=&r" (old), "=&r" (tmp), "=m" (*p)
	: "r" ((unsigned long)(p+1) - 4), "r" (clr), "r" (set), "m" (*p)
	: "cc" );
	return old;
}

/*
 * set_pte stores a linux PTE into the linux page table.
 * On machines which use an MMU hash table we avoid changing the
 * _PAGE_HASHPTE bit.
 */
static inline void set_pte(pte_t *ptep, pte_t pte)
{
#if _PAGE_HASHPTE != 0
	pte_update(ptep, ~_PAGE_HASHPTE, pte_val(pte) & ~_PAGE_HASHPTE);
#else
	*ptep = pte;
#endif
}

extern void flush_hash_one_pte(pte_t *ptep);

/*
 * 2.6 calles this without flushing the TLB entry, this is wrong
 * for our hash-based implementation, we fix that up here
 */
static inline int ptep_test_and_clear_young(pte_t *ptep)
{
	unsigned long old;
	old = (pte_update(ptep, _PAGE_ACCESSED, 0) & _PAGE_ACCESSED);
#if _PAGE_HASHPTE != 0
	if (old & _PAGE_HASHPTE)
		flush_hash_one_pte(ptep);
#endif
	return old != 0;
}

static inline int ptep_test_and_clear_dirty(pte_t *ptep)
{
	return (pte_update(ptep, (_PAGE_DIRTY | _PAGE_HWWRITE), 0) & _PAGE_DIRTY) != 0;
}

static inline pte_t ptep_get_and_clear(pte_t *ptep)
{
	return __pte(pte_update(ptep, ~_PAGE_HASHPTE, 0));
}

static inline void ptep_set_wrprotect(pte_t *ptep)
{
	pte_update(ptep, (_PAGE_RW | _PAGE_HWWRITE), 0);
}

static inline void ptep_mkdirty(pte_t *ptep)
{
	pte_update(ptep, 0, _PAGE_DIRTY);
}

#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry, int dirty)
{
	unsigned long bits = pte_val(entry) &
		(_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW);
	pte_update(ptep, 0, bits);
}

#define  ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
	do {								   \
		__ptep_set_access_flags(__ptep, __entry, __dirty);	   \
		flush_tlb_page_nohash(__vma, __address);	       	   \
	} while(0)

/*
 * Macro to mark a page protection value as "uncacheable".
 */
#define pgprot_noncached(prot)	(__pgprot(pgprot_val(prot) | _PAGE_NO_CACHE | _PAGE_GUARDED))

#define pte_same(A,B)	(((pte_val(A) ^ pte_val(B)) & ~_PAGE_HASHPTE) == 0)

/*
 * Note that on Book E processors, the pmd contains the kernel virtual
 * (lowmem) address of the pte page.  The physical address is less useful
 * because everything runs with translation enabled (even the TLB miss
 * handler).  On everything else the pmd contains the physical address
 * of the pte page.  -- paulus
 */
#ifndef CONFIG_BOOKE
#define pmd_page_kernel(pmd)	\
	((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
#define pmd_page(pmd)		\
	(mem_map + (pmd_val(pmd) >> PAGE_SHIFT))
#else
#define pmd_page_kernel(pmd)	\
	((unsigned long) (pmd_val(pmd) & PAGE_MASK))
#define pmd_page(pmd)		\
	(mem_map + (__pa(pmd_val(pmd)) >> PAGE_SHIFT))
#endif

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

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

/* Find an entry in the third-level page table.. */
#define pte_index(address)		\
	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
#define pte_offset_kernel(dir, addr)	\
	((pte_t *) pmd_page_kernel(*(dir)) + pte_index(addr))
#define pte_offset_map(dir, addr)		\
	((pte_t *) kmap_atomic(pmd_page(*(dir)), KM_PTE0) + pte_index(addr))
#define pte_offset_map_nested(dir, addr)	\
	((pte_t *) kmap_atomic(pmd_page(*(dir)), KM_PTE1) + pte_index(addr))

#define pte_unmap(pte)		kunmap_atomic(pte, KM_PTE0)
#define pte_unmap_nested(pte)	kunmap_atomic(pte, KM_PTE1)

extern pgd_t swapper_pg_dir[PTRS_PER_PGD];

extern void paging_init(void);

/*
 * When flushing the tlb entry for a page, we also need to flush the hash
 * table entry.  flush_hash_pages is assembler (for speed) in hashtable.S.
 */
extern int flush_hash_pages(unsigned context, unsigned long va,
			    unsigned long pmdval, int count);

/* Add an HPTE to the hash table */
extern void add_hash_page(unsigned context, unsigned long va,
			  unsigned long pmdval);

/*
 * Encode and decode a swap entry.
 * Note that the bits we use in a PTE for representing a swap entry
 * must not include the _PAGE_PRESENT bit, the _PAGE_FILE bit, or the
 *_PAGE_HASHPTE bit (if used).  -- paulus
 */
#define __swp_type(entry)		((entry).val & 0x1f)
#define __swp_offset(entry)		((entry).val >> 5)
#define __swp_entry(type, offset)	((swp_entry_t) { (type) | ((offset) << 5) })
#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) >> 3 })
#define __swp_entry_to_pte(x)		((pte_t) { (x).val << 3 })

/* Encode and decode a nonlinear file mapping entry */
#define PTE_FILE_MAX_BITS	29
#define pte_to_pgoff(pte)	(pte_val(pte) >> 3)
#define pgoff_to_pte(off)	((pte_t) { ((off) << 3) | _PAGE_FILE })

/* CONFIG_APUS */
/* For virtual address to physical address conversion */
extern void cache_clear(__u32 addr, int length);
extern void cache_push(__u32 addr, int length);
extern int mm_end_of_chunk (unsigned long addr, int len);
extern unsigned long iopa(unsigned long addr);
extern unsigned long mm_ptov(unsigned long addr) __attribute_const__;

/* Values for nocacheflag and cmode */
/* These are not used by the APUS kernel_map, but prevents
   compilation errors. */
#define	KERNELMAP_FULL_CACHING		0
#define	KERNELMAP_NOCACHE_SER		1
#define	KERNELMAP_NOCACHE_NONSER	2
#define	KERNELMAP_NO_COPYBACK		3

/*
 * Map some physical address range into the kernel address space.
 */
extern unsigned long kernel_map(unsigned long paddr, unsigned long size,
				int nocacheflag, unsigned long *memavailp );

/*
 * Set cache mode of (kernel space) address range.
 */
extern void kernel_set_cachemode (unsigned long address, unsigned long size,
                                 unsigned int cmode);

/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
#define kern_addr_valid(addr)	(1)

#define io_remap_page_range remap_page_range

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

extern int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep);

#endif /* !__ASSEMBLY__ */

#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
#define __HAVE_ARCH_PTEP_SET_WRPROTECT
#define __HAVE_ARCH_PTEP_MKDIRTY
#define __HAVE_ARCH_PTE_SAME
#include <asm-generic/pgtable.h>

#endif /* _PPC_PGTABLE_H */
#endif /* __KERNEL__ */