pgalloc.h

嵌入式系统设计与实例开发实验教材二源码 多线程应用程序设计 串行端口程序设计 AD接口实验 CAN总线通信实验 GPS通信实验 Linux内核移植与编译实验 IC卡读写实验 SD驱动使

#ifndef __ASM_SH_PGALLOC_H
#define __ASM_SH_PGALLOC_H

#include <asm/processor.h>
#include <linux/threads.h>
#include <linux/slab.h>

#define pgd_quicklist ((unsigned long *)0)
#define pmd_quicklist ((unsigned long *)0)
#define pte_quicklist ((unsigned long *)0)
#define pgtable_cache_size 0L

#define pmd_populate(mm, pmd, pte) \
		set_pmd(pmd, __pmd(_PAGE_TABLE + __pa(pte)))

/*
 * Allocate and free page tables.
 */

static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
	unsigned int pgd_size = (USER_PTRS_PER_PGD * sizeof(pgd_t));
	pgd_t *pgd = (pgd_t *)kmalloc(pgd_size, GFP_KERNEL);

	if (pgd)
		memset(pgd, 0, pgd_size);

	return pgd;
}

static inline void pgd_free(pgd_t *pgd)
{
	kfree(pgd);
}

static inline pte_t *pte_alloc_one(struct mm_struct *mm, unsigned long address)
{
	pte_t *pte = (pte_t *) __get_free_page(GFP_KERNEL);
	if (pte)
		clear_page(pte);
	return pte;
}

static inline pte_t *pte_alloc_one_fast(struct mm_struct *mm, unsigned long address)
{
	return 0;
}

static inline void pte_free_slow(pte_t *pte)
{
	free_page((unsigned long)pte);
}

#define pte_free(pte)		pte_free_slow(pte)

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

#define pmd_alloc_one_fast(mm, addr)	({ BUG(); ((pmd_t *)1); })
#define pmd_alloc_one(mm, addr)		({ BUG(); ((pmd_t *)2); })
#define pmd_free_slow(x)		do { } while (0)
#define pmd_free_fast(x)		do { } while (0)
#define pmd_free(x)			do { } while (0)
#define pgd_populate(mm, pmd, pte)	BUG()

/* Do nothing */
static inline int do_check_pgt_cache(int low, int high) { }

/*
 * TLB flushing:
 *
 *  - flush_tlb() flushes the current mm struct TLBs
 *  - flush_tlb_all() flushes all processes TLBs
 *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
 *  - flush_tlb_page(vma, vmaddr) flushes one page
 *  - flush_tlb_range(mm, start, end) flushes a range of pages
 *  - flush_tlb_pgtables(mm, start, end) flushes a range of page tables
 */

extern void flush_tlb(void);
extern void flush_tlb_all(void);
extern void flush_tlb_mm(struct mm_struct *mm);
extern void flush_tlb_range(struct mm_struct *mm, unsigned long start,
			    unsigned long end);
extern void flush_tlb_page(struct vm_area_struct *vma, unsigned long page);
extern void __flush_tlb_page(unsigned long asid, unsigned long page);

static inline void flush_tlb_pgtables(struct mm_struct *mm,
				      unsigned long start, unsigned long end)
{ /* Nothing to do */
}

#if defined(__SH4__)
/*
 * For SH-4, we have our own implementation for ptep_get_and_clear
 */
static inline pte_t ptep_get_and_clear(pte_t *ptep)
{
	pte_t pte = *ptep;

	pte_clear(ptep);
	if (!pte_not_present(pte)) {
		struct page *page = pte_page(pte);
		if (VALID_PAGE(page)&&
		    (!page->mapping || !(page->mapping->i_mmap_shared)))
			__clear_bit(PG_mapped, &page->flags);
	}
	return pte;
}
#else
static inline pte_t ptep_get_and_clear(pte_t *ptep)
{
	pte_t pte = *ptep;
	pte_clear(ptep);
	return pte;
}
#endif

/*
 * Following functions are same as generic ones.
 */
static inline int ptep_test_and_clear_young(pte_t *ptep)
{
	pte_t pte = *ptep;
	if (!pte_young(pte))
		return 0;
	set_pte(ptep, pte_mkold(pte));
	return 1;
}

static inline int ptep_test_and_clear_dirty(pte_t *ptep)
{
	pte_t pte = *ptep;
	if (!pte_dirty(pte))
		return 0;
	set_pte(ptep, pte_mkclean(pte));
	return 1;
}

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_t old_pte = *ptep;
	set_pte(ptep, pte_mkdirty(old_pte));
}
#endif /* __ASM_SH_PGALLOC_H */