pgtable.h

嵌入式ARM的一些源代码

	if (!mem_map[MAP_NR(pgdp)].reserved)
		mem_map[MAP_NR(pgdp)].count++;
}
*/

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

extern inline pte_t pte_wrprotect(pte_t pte)	{ pte_val(pte) &= ~_PAGE_RW; return pte; }
extern inline pte_t pte_rdprotect(pte_t pte)	{ pte_val(pte) &= ~_PAGE_USER; return pte; }
extern inline pte_t pte_exprotect(pte_t pte)	{ pte_val(pte) &= ~_PAGE_USER; return pte; }
extern inline pte_t pte_mkclean(pte_t pte)	{ pte_val(pte) &= ~_PAGE_DIRTY; return pte; }
extern inline pte_t pte_mkold(pte_t pte)	{ pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
extern inline pte_t pte_uncow(pte_t pte)	{ pte_val(pte) &= ~_PAGE_COW; return pte; }
extern inline pte_t pte_mkwrite(pte_t pte)	{ pte_val(pte) |= _PAGE_RW; return pte; }
extern inline pte_t pte_mkread(pte_t pte)	{ pte_val(pte) |= _PAGE_USER; return pte; }
extern inline pte_t pte_mkexec(pte_t pte)	{ pte_val(pte) |= _PAGE_USER; return pte; }
extern inline pte_t pte_mkdirty(pte_t pte)	{ pte_val(pte) |= _PAGE_DIRTY; return pte; }
extern inline pte_t pte_mkyoung(pte_t pte)	{ pte_val(pte) |= _PAGE_ACCESSED; return pte; }
extern inline pte_t pte_mkcow(pte_t pte)	{ pte_val(pte) |= _PAGE_COW; return pte; }

/*
 * Conversion functions: convert a page and protection to a page entry,
 * and a page entry and page directory to the page they refer to.
 */
extern inline pte_t mk_pte(unsigned long page, pgprot_t pgprot)
{ pte_t pte; pte_val(pte) = page | pgprot_val(pgprot); return pte; }

extern 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; }

/*extern inline void pmd_set(pmd_t * pmdp, pte_t * ptep)
{ pmd_val(*pmdp) = _PAGE_TABLE | ((((unsigned long) ptep) - PAGE_OFFSET) << (32-PAGE_SHIFT)); }
*/
extern inline unsigned long pte_page(pte_t pte)
{ return pte_val(pte) & PAGE_MASK; }

extern inline unsigned long pmd_page(pmd_t pmd)
{ return pmd_val(pmd) & PAGE_MASK; }


/* to find an entry in a page-table-directory */
extern inline pgd_t * pgd_offset(struct mm_struct * mm, unsigned long address)
{
	return mm->pgd + (address >> PGDIR_SHIFT);
}

/* 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;
}

/* Find an entry in the third-level page table.. */ 
extern inline pte_t * pte_offset(pmd_t * dir, unsigned long address)
{
	return (pte_t *) pmd_page(*dir) + ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
}


/*
 * Allocate and free page tables. The xxx_kernel() versions are
 * used to allocate a kernel page table - this turns on ASN bits
 * if any, and marks the page tables reserved.
 */
extern inline void pte_free_kernel(pte_t * pte)
{
	free_page((unsigned long) pte);
}
/*extern inline void pte_free_kernel(pte_t * pte)
{
	mem_map[MAP_NR(pte)] = 1;
	free_page((unsigned long) pte);
}
*/

/*
extern inline pte_t * pte_alloc_kernel(pmd_t * pmd, unsigned long address)
{
	address = (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
	if (pmd_none(*pmd)) {
		pte_t * page = (pte_t *) get_free_page(GFP_KERNEL);
		if (pmd_none(*pmd)) {
			if (page) {
				pmd_val(*pmd) = _PAGE_TABLE | (unsigned long) page;
				mem_map[MAP_NR(page)] = MAP_PAGE_RESERVED;
				return page + address;
			}
			pmd_val(*pmd) = _PAGE_TABLE | (unsigned long) BAD_PAGETABLE;
			return NULL;
		}
		free_page((unsigned long) page);
	}
	if (pmd_bad(*pmd)) {
		printk("Bad pmd in pte_alloc: %08lx\n", pmd_val(*pmd));
		pmd_val(*pmd) = _PAGE_TABLE | (unsigned long) BAD_PAGETABLE;
		return NULL;
	}
	return (pte_t *) pmd_page(*pmd) + address;
}*/
/*
extern inline pte_t * pte_alloc_kernel(pmd_t *pmd, unsigned long address)
{
printk("pte_alloc_kernel pmd = %08X, address = %08X\n", pmd, address);
	address = (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
printk("address now = %08X\n", address);
	if (pmd_none(*pmd)) {
		pte_t *page;
printk("pmd_none(*pmd) true\n");
		page = (pte_t *) get_free_page(GFP_KERNEL);
printk("page = %08X after get_free_page(%08X)\n",page,GFP_KERNEL);
		if (pmd_none(*pmd)) {
printk("pmd_none(*pmd=%08X) still\n",*pmd);		  
			if (page) {
printk("page true = %08X\n",page);			  
				pmd_set(pmd, page);
printk("pmd_set(%08X,%08X)\n",pmd,page);			  
				mem_map[MAP_NR(page)].reserved = 1;
printk("did mem_map\n",pmd,page);			  
				return page + address;
			}
printk("did pmd_set(%08X, %08X\n",pmd,BAD_PAGETABLE);			  
			pmd_set(pmd, (pte_t *) BAD_PAGETABLE);
			return NULL;
		}
printk("did free_page(%08X)\n",page);			  		
		free_page((unsigned long) page);
	}
	if (pmd_bad(*pmd)) {
		printk("Bad pmd in pte_alloc: %08lx\n", pmd_val(*pmd));
		pmd_set(pmd, (pte_t *) BAD_PAGETABLE);
		return NULL;
	}
printk("returning pmd_page(%08X) + %08X\n",pmd_page(*pmd) , address);	  

	return (pte_t *) pmd_page(*pmd) + address;
}
*/
extern inline pte_t * pte_alloc_kernel(pmd_t * pmd, unsigned long address)
{
	address = (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
	if (pmd_none(*pmd)) {
		pte_t * page = (pte_t *) get_free_page(GFP_KERNEL);
		if (pmd_none(*pmd)) {
			if (page) {
/*                                pmd_set(pmd,page);*/
			pmd_val(*pmd) = _PAGE_TABLE | (unsigned long) page;
				return page + address;
			}
/*			pmd_set(pmd, BAD_PAGETABLE);*/
			pmd_val(*pmd) = _PAGE_TABLE | (unsigned long) BAD_PAGETABLE;
			return NULL;
		}
		free_page((unsigned long) page);
	}
	if (pmd_bad(*pmd)) {
		printk("Bad pmd in pte_alloc: %08lx\n", pmd_val(*pmd));
/*		pmd_set(pmd, (pte_t *) BAD_PAGETABLE);		*/
		pmd_val(*pmd) = _PAGE_TABLE | (unsigned long) BAD_PAGETABLE;
		return NULL;
	}
	return (pte_t *) pmd_page(*pmd) + address;
}

/*
 * allocating and freeing a pmd is trivial: the 1-entry pmd is
 * inside the pgd, so has no extra memory associated with it.
 */
extern inline void pmd_free_kernel(pmd_t * pmd)
{
}

extern inline pmd_t * pmd_alloc_kernel(pgd_t * pgd, unsigned long address)
{
	return (pmd_t *) pgd;
}

extern inline void pte_free(pte_t * pte)
{
	free_page((unsigned long) pte);
}

extern inline pte_t * pte_alloc(pmd_t * pmd, unsigned long address)
{
	address = (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
	if (pmd_none(*pmd)) {
		pte_t * page = (pte_t *) get_free_page(GFP_KERNEL);
		if (pmd_none(*pmd)) {
			if (page) {
				pmd_val(*pmd) = _PAGE_TABLE | (unsigned long) page;
				return page + address;
			}
			pmd_val(*pmd) = _PAGE_TABLE | (unsigned long) BAD_PAGETABLE;
			return NULL;
		}
		free_page((unsigned long) page);
	}
	if (pmd_bad(*pmd)) {
		printk("Bad pmd in pte_alloc: %08lx\n", pmd_val(*pmd));
		pmd_val(*pmd) = _PAGE_TABLE | (unsigned long) BAD_PAGETABLE;
		return NULL;
	}
	return (pte_t *) pmd_page(*pmd) + address;
}

/*
 * allocating and freeing a pmd is trivial: the 1-entry pmd is
 * inside the pgd, so has no extra memory associated with it.
 */
extern inline void pmd_free(pmd_t * pmd)
{
}

extern inline pmd_t * pmd_alloc(pgd_t * pgd, unsigned long address)
{
	return (pmd_t *) pgd;
}

extern inline void pgd_free(pgd_t * pgd)
{
	free_page((unsigned long) pgd);
}

extern inline pgd_t * pgd_alloc(void)
{
	return (pgd_t *) get_free_page(GFP_KERNEL);
}

extern pgd_t swapper_pg_dir[1024*8];
/*extern pgd_t *swapper_pg_dir;*/

/*
 * Software maintained MMU tables may have changed -- update the
 * hardware [aka cache]
 */
extern inline void update_mmu_cache(struct vm_area_struct * vma,
	unsigned long address, pte_t _pte)
{
#if 0
	printk("Update MMU cache - VMA: %x, Addr: %x, PTE: %x\n", vma, address, *(long *)&_pte);
	_printk("Update MMU cache - VMA: %x, Addr: %x, PTE: %x\n", vma, address, *(long *)&_pte);
/*	MMU_hash_page(&(vma->vm_task)->tss, address & PAGE_MASK, (pte *)&_pte);*/
#endif	
	MMU_hash_page(&(current)->tss, address & PAGE_MASK, (pte *)&_pte);

}


#ifdef _SCHED_INIT_
#define INIT_MMAP { &init_task, 0, 0x40000000, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC }

#endif	

#define SWP_TYPE(entry) (((entry) >> 1) & 0x7f)
#define SWP_OFFSET(entry) ((entry) >> 8)
#define SWP_ENTRY(type,offset) (((type) << 1) | ((offset) << 8))

#endif /* _PPC_PAGE_H */