pgtable.h

来自「Linux Kernel 2.6.9 for OMAP1710」· C头文件 代码 · 共 523 行 · 第 1/2 页

#ifndef _PARISC_PGTABLE_H
#define _PARISC_PGTABLE_H

#include <linux/config.h>
#include <asm/fixmap.h>

#ifndef __ASSEMBLY__
/*
 * we simulate an x86-style page table for the linux mm code
 */

#include <linux/spinlock.h>
#include <asm/processor.h>
#include <asm/cache.h>
#include <asm/bitops.h>

/*
 * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
 * memory.  For the return value to be meaningful, ADDR must be >=
 * PAGE_OFFSET.  This operation can be relatively expensive (e.g.,
 * require a hash-, or multi-level tree-lookup or something of that
 * sort) but it guarantees to return TRUE only if accessing the page
 * at that address does not cause an error.  Note that there may be
 * addresses for which kern_addr_valid() returns FALSE even though an
 * access would not cause an error (e.g., this is typically true for
 * memory mapped I/O regions.
 *
 * XXX Need to implement this for parisc.
 */
#define kern_addr_valid(addr)	(1)

/* Certain architectures need to do special things when PTEs
 * within a page table are directly modified.  Thus, the following
 * hook is made available.
 */
#define set_pte(pteptr, pteval)                                 \
        do{                                                     \
                *(pteptr) = (pteval);                           \
        } while(0)

#endif /* !__ASSEMBLY__ */

#define pte_ERROR(e) \
	printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
#define pmd_ERROR(e) \
	printk("%s:%d: bad pmd %08lx.\n", __FILE__, __LINE__, (unsigned long)pmd_val(e))
#define pgd_ERROR(e) \
	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, (unsigned long)pgd_val(e))

 /* Note: If you change ISTACK_SIZE, you need to change the corresponding
  * values in vmlinux.lds and vmlinux64.lds (init_istack section). Also,
  * the "order" and size need to agree.
  */

#define  ISTACK_SIZE  32768 /* Interrupt Stack Size */
#define  ISTACK_ORDER 3

/* This is the size of the initially mapped kernel memory (i.e. currently
 * 0 to 1<<23 == 8MB */
#ifdef CONFIG_64BIT
#define KERNEL_INITIAL_ORDER	24
#else
#define KERNEL_INITIAL_ORDER	23
#endif
#define KERNEL_INITIAL_SIZE	(1 << KERNEL_INITIAL_ORDER)

#ifdef CONFIG_64BIT
#define PT_NLEVELS	3
#define PGD_ORDER	1 /* Number of pages per pgd */
#define PMD_ORDER	1 /* Number of pages per pmd */
#define PGD_ALLOC_ORDER	2 /* first pgd contains pmd */
#else
#define PT_NLEVELS	2
#define PGD_ORDER	1 /* Number of pages per pgd */
#define PGD_ALLOC_ORDER	PGD_ORDER
#endif

/* Definitions for 3rd level (we use PLD here for Page Lower directory
 * because PTE_SHIFT is used lower down to mean shift that has to be
 * done to get usable bits out of the PTE) */
#define PLD_SHIFT	PAGE_SHIFT
#define PLD_SIZE	PAGE_SIZE
#define BITS_PER_PTE	(PAGE_SHIFT - BITS_PER_PTE_ENTRY)
#define PTRS_PER_PTE    (1UL << BITS_PER_PTE)

/* Definitions for 2nd level */
#define pgtable_cache_init()	do { } while (0)

#define PMD_SHIFT       (PLD_SHIFT + BITS_PER_PTE)
#define PMD_SIZE	(1UL << PMD_SHIFT)
#define PMD_MASK	(~(PMD_SIZE-1))
#if PT_NLEVELS == 3
#define BITS_PER_PMD	(PAGE_SHIFT + PMD_ORDER - BITS_PER_PMD_ENTRY)
#else
#define BITS_PER_PMD	0
#endif
#define PTRS_PER_PMD    (1UL << BITS_PER_PMD)

/* Definitions for 1st level */
#define PGDIR_SHIFT	(PMD_SHIFT + BITS_PER_PMD)
#define BITS_PER_PGD	(PAGE_SHIFT + PGD_ORDER - BITS_PER_PGD_ENTRY)
#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
#define PGDIR_MASK	(~(PGDIR_SIZE-1))
#define PTRS_PER_PGD    (1UL << BITS_PER_PGD)
#define USER_PTRS_PER_PGD       PTRS_PER_PGD

#define MAX_ADDRBITS	(PGDIR_SHIFT + BITS_PER_PGD)
#define MAX_ADDRESS	(1UL << MAX_ADDRBITS)

#define SPACEID_SHIFT (MAX_ADDRBITS - 32)

/* This calculates the number of initial pages we need for the initial
 * page tables */
#define PT_INITIAL	(1 << (KERNEL_INITIAL_ORDER - PMD_SHIFT))

/*
 * pgd entries used up by user/kernel:
 */

#define FIRST_USER_PGD_NR	0

#ifndef __ASSEMBLY__
extern  void *vmalloc_start;
#define PCXL_DMA_MAP_SIZE   (8*1024*1024)
#define VMALLOC_START   ((unsigned long)vmalloc_start)
/* this is a fixmap remnant, see fixmap.h */
#define VMALLOC_END	(KERNEL_MAP_END)
#endif

/* NB: The tlb miss handlers make certain assumptions about the order */
/*     of the following bits, so be careful (One example, bits 25-31  */
/*     are moved together in one instruction).                        */

#define _PAGE_READ_BIT     31   /* (0x001) read access allowed */
#define _PAGE_WRITE_BIT    30   /* (0x002) write access allowed */
#define _PAGE_EXEC_BIT     29   /* (0x004) execute access allowed */
#define _PAGE_GATEWAY_BIT  28   /* (0x008) privilege promotion allowed */
#define _PAGE_DMB_BIT      27   /* (0x010) Data Memory Break enable (B bit) */
#define _PAGE_DIRTY_BIT    26   /* (0x020) Page Dirty (D bit) */
#define _PAGE_FILE_BIT	_PAGE_DIRTY_BIT	/* overload this bit */
#define _PAGE_REFTRAP_BIT  25   /* (0x040) Page Ref. Trap enable (T bit) */
#define _PAGE_NO_CACHE_BIT 24   /* (0x080) Uncached Page (U bit) */
#define _PAGE_ACCESSED_BIT 23   /* (0x100) Software: Page Accessed */
#define _PAGE_PRESENT_BIT  22   /* (0x200) Software: translation valid */
#define _PAGE_FLUSH_BIT    21   /* (0x400) Software: translation valid */
				/*             for cache flushing only */
#define _PAGE_USER_BIT     20   /* (0x800) Software: User accessible page */

/* N.B. The bits are defined in terms of a 32 bit word above, so the */
/*      following macro is ok for both 32 and 64 bit.                */

#define xlate_pabit(x) (31 - x)

/* this defines the shift to the usable bits in the PTE it is set so
 * that the valid bits _PAGE_PRESENT_BIT and _PAGE_USER_BIT are set
 * to zero */
#define PTE_SHIFT	   	xlate_pabit(_PAGE_USER_BIT)

/* this is how many bits may be used by the file functions */
#define PTE_FILE_MAX_BITS	(BITS_PER_LONG - PTE_SHIFT)

#define pte_to_pgoff(pte) (pte_val(pte) >> PTE_SHIFT)
#define pgoff_to_pte(off) ((pte_t) { ((off) << PTE_SHIFT) | _PAGE_FILE })

#define _PAGE_READ     (1 << xlate_pabit(_PAGE_READ_BIT))
#define _PAGE_WRITE    (1 << xlate_pabit(_PAGE_WRITE_BIT))
#define _PAGE_RW       (_PAGE_READ | _PAGE_WRITE)
#define _PAGE_EXEC     (1 << xlate_pabit(_PAGE_EXEC_BIT))
#define _PAGE_GATEWAY  (1 << xlate_pabit(_PAGE_GATEWAY_BIT))
#define _PAGE_DMB      (1 << xlate_pabit(_PAGE_DMB_BIT))
#define _PAGE_DIRTY    (1 << xlate_pabit(_PAGE_DIRTY_BIT))
#define _PAGE_REFTRAP  (1 << xlate_pabit(_PAGE_REFTRAP_BIT))
#define _PAGE_NO_CACHE (1 << xlate_pabit(_PAGE_NO_CACHE_BIT))
#define _PAGE_ACCESSED (1 << xlate_pabit(_PAGE_ACCESSED_BIT))
#define _PAGE_PRESENT  (1 << xlate_pabit(_PAGE_PRESENT_BIT))
#define _PAGE_FLUSH    (1 << xlate_pabit(_PAGE_FLUSH_BIT))
#define _PAGE_USER     (1 << xlate_pabit(_PAGE_USER_BIT))
#define _PAGE_FILE     (1 << xlate_pabit(_PAGE_FILE_BIT))

#define _PAGE_TABLE	(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE |  _PAGE_DIRTY | _PAGE_ACCESSED)
#define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
#define _PAGE_KERNEL	(_PAGE_PRESENT | _PAGE_EXEC | _PAGE_READ | _PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED)

/* The pgd/pmd contains a ptr (in phys addr space); since all pgds/pmds
 * are page-aligned, we don't care about the PAGE_OFFSET bits, except
 * for a few meta-information bits, so we shift the address to be
 * able to effectively address 40-bits of physical address space. */
#define _PxD_PRESENT_BIT   31
#define _PxD_ATTACHED_BIT  30
#define _PxD_VALID_BIT     29

#define PxD_FLAG_PRESENT  (1 << xlate_pabit(_PxD_PRESENT_BIT))
#define PxD_FLAG_ATTACHED (1 << xlate_pabit(_PxD_ATTACHED_BIT))
#define PxD_FLAG_VALID    (1 << xlate_pabit(_PxD_VALID_BIT))
#define PxD_FLAG_MASK     (0xf)
#define PxD_FLAG_SHIFT    (4)
#define PxD_VALUE_SHIFT   (8)

#ifndef __ASSEMBLY__

#define PAGE_NONE	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_WRITE | _PAGE_ACCESSED)
/* Others seem to make this executable, I don't know if that's correct
   or not.  The stack is mapped this way though so this is necessary
   in the short term - [e-mail], 2000-08-08 */
#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_ACCESSED)
#define PAGE_WRITEONLY  __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_WRITE | _PAGE_ACCESSED)
#define PAGE_EXECREAD   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_EXEC |_PAGE_ACCESSED)
#define PAGE_COPY       PAGE_EXECREAD
#define PAGE_RWX        __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC |_PAGE_ACCESSED)
#define PAGE_KERNEL	__pgprot(_PAGE_KERNEL)
#define PAGE_KERNEL_RO	__pgprot(_PAGE_PRESENT | _PAGE_EXEC | _PAGE_READ | _PAGE_DIRTY | _PAGE_ACCESSED)
#define PAGE_KERNEL_UNC	__pgprot(_PAGE_KERNEL | _PAGE_NO_CACHE)
#define PAGE_GATEWAY    __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_GATEWAY| _PAGE_READ)
#define PAGE_FLUSH      __pgprot(_PAGE_FLUSH)


/*
 * We could have an execute only page using "gateway - promote to priv
 * level 3", but that is kind of silly. So, the way things are defined
 * now, we must always have read permission for pages with execute
 * permission. For the fun of it we'll go ahead and support write only
 * pages.
 */

	 /*xwr*/
#define __P000  PAGE_NONE
#define __P001  PAGE_READONLY
#define __P010  __P000 /* copy on write */
#define __P011  __P001 /* copy on write */
#define __P100  PAGE_EXECREAD
#define __P101  PAGE_EXECREAD
#define __P110  __P100 /* copy on write */
#define __P111  __P101 /* copy on write */

#define __S000  PAGE_NONE
#define __S001  PAGE_READONLY
#define __S010  PAGE_WRITEONLY
#define __S011  PAGE_SHARED
#define __S100  PAGE_EXECREAD
#define __S101  PAGE_EXECREAD
#define __S110  PAGE_RWX
#define __S111  PAGE_RWX

extern pgd_t swapper_pg_dir[]; /* declared in init_task.c */

/* initial page tables for 0-8MB for kernel */

extern pte_t pg0[];

/* zero page used for uninitialized stuff */

extern unsigned long *empty_zero_page;

/*
 * ZERO_PAGE is a global shared page that is always zero: used
 * for zero-mapped memory areas etc..
 */

#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))

#define pte_none(x)     ((pte_val(x) == 0) || (pte_val(x) & _PAGE_FLUSH))