pgtable.h

嵌入式ARM的一些源代码

 * used to allocate a kernel page table - this turns on ASN bits
 * if any.
 */

extern inline void nocache_page (unsigned long vaddr)
{
	if (m68k_is040or060) {
		pgd_t *dir;
		pmd_t *pmdp;
		pte_t *ptep;

		dir = pgd_offset_k(vaddr);
		pmdp = pmd_offset(dir,vaddr);
		ptep = pte_offset(pmdp,vaddr);
		*ptep = pte_mknocache(*ptep);
	}
}

static inline void cache_page (unsigned long vaddr)
{
	if (m68k_is040or060) {
		pgd_t *dir;
		pmd_t *pmdp;
		pte_t *ptep;

		dir = pgd_offset_k(vaddr);
		pmdp = pmd_offset(dir,vaddr);
		ptep = pte_offset(pmdp,vaddr);
		*ptep = pte_mkcache(*ptep);
	}
}


extern const char PgtabStr_bad_pmd[];
extern const char PgtabStr_bad_pgd[];
extern const char PgtabStr_bad_pmdk[];
extern const char PgtabStr_bad_pgdk[];

extern inline void pte_free(pte_t * pte)
{
	cache_page((unsigned long)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) {
				nocache_page((unsigned long)page);
				pmd_set(pmd,page);
				return page + address;
			}
			pmd_set(pmd, BAD_PAGETABLE);
			return NULL;
		}
		free_page((unsigned long)page);
	}
	if (pmd_bad(*pmd)) {
		printk(PgtabStr_bad_pmd, pmd_val(*pmd));
		pmd_set(pmd, BAD_PAGETABLE);
		return NULL;
	}
	return (pte_t *) pmd_page(*pmd) + address;
}

extern pmd_t *get_pointer_table (void);
extern void free_pointer_table (pmd_t *);
extern pmd_t *get_kpointer_table (void);
extern void free_kpointer_table (pmd_t *);

extern inline void pmd_free(pmd_t * pmd)
{
	free_pointer_table (pmd);
}

extern inline pmd_t * pmd_alloc(pgd_t * pgd, unsigned long address)
{
	address = (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
	if (pgd_none(*pgd)) {
		pmd_t *page = get_pointer_table();
		if (pgd_none(*pgd)) {
			if (page) {
				pgd_set(pgd, page);
				return page + address;
			}
			pgd_set(pgd, (pmd_t *)BAD_PAGETABLE);
			return NULL;
		}
		free_pointer_table(page);
	}
	if (pgd_bad(*pgd)) {
		printk(PgtabStr_bad_pgd, pgd_val(*pgd));
		pgd_set(pgd, (pmd_t *)BAD_PAGETABLE);
		return NULL;
	}
	return (pmd_t *) pgd_page(*pgd) + address;
}

extern inline void pte_free_kernel(pte_t * pte)
{
	cache_page((unsigned long)pte);
	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) {
				nocache_page((unsigned long)page);
				pmd_set(pmd, page);
				return page + address;
			}
			pmd_set(pmd, BAD_PAGETABLE);
			return NULL;
		}
		free_page((unsigned long) page);
	}
	if (pmd_bad(*pmd)) {
		printk(PgtabStr_bad_pmdk, pmd_val(*pmd));
		pmd_set(pmd, BAD_PAGETABLE);
		return NULL;
	}
	return (pte_t *) pmd_page(*pmd) + address;
}

extern inline void pmd_free_kernel(pmd_t * pmd)
{
	free_kpointer_table(pmd);
}

extern inline pmd_t * pmd_alloc_kernel(pgd_t * pgd, unsigned long address)
{
	address = (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
	if (pgd_none(*pgd)) {
		pmd_t *page = get_kpointer_table();
		if (pgd_none(*pgd)) {
			if (page) {
				pgd_set(pgd, page);
				return page + address;
			}
			pgd_set(pgd, (pmd_t *)BAD_PAGETABLE);
			return NULL;
		}
		free_kpointer_table(page);
	}
	if (pgd_bad(*pgd)) {
		printk(PgtabStr_bad_pgdk, pgd_val(*pgd));
		pgd_set(pgd, (pmd_t *)BAD_PAGETABLE);
		return NULL;
	}
	return (pmd_t *) pgd_page(*pgd) + address;
}

extern inline void pgd_free(pgd_t * pgd)
{
	free_pointer_table ((pmd_t *) pgd);
}

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

#define flush_icache() \
do { \
	if (m68k_is040or060) \
		asm ("nop; .word 0xf498 /* cinva %%ic */"); \
	else \
		asm ("movec %/cacr,%/d0;" \
		     "oriw %0,%/d0;" \
		     "movec %/d0,%/cacr" \
		     : /* no outputs */ \
		     : "i" (FLUSH_I) \
		     : "d0"); \
} while (0)

/*
 * invalidate the cache for the specified memory range.
 * It starts at the physical address specified for
 * the given number of bytes.
 */
extern void cache_clear (unsigned long paddr, int len);
/*
 * push any dirty cache in the specified memory range.
 * It starts at the physical address specified for
 * the given number of bytes.
 */
extern void cache_push (unsigned long paddr, int len);

/*
 * push and invalidate pages in the specified user virtual
 * memory range.
 */
extern void cache_push_v (unsigned long vaddr, int len);

/* cache code */
#define FLUSH_I_AND_D	(0x00000808)
#define FLUSH_I 	(0x00000008)

/* This is needed whenever the virtual mapping of the current
   process changes.  */
#define __flush_cache_all()						\
    do {								\
	if (m68k_is040or060)					        \
               __asm__ __volatile__ ("nop; .word 0xf478\n" ::);         \
        else                                                            \
	       __asm__ __volatile__ ("movec %%cacr,%%d0\n\t"		\
				     "orw %0,%%d0\n\t"			\
				     "movec %%d0,%%cacr"		\
				     : : "di" (FLUSH_I_AND_D) : "d0");	\
    } while (0)

#define __flush_cache_030()						\
    do {								\
	if (m68k_is040or060 == 0)					\
	       __asm__ __volatile__ ("movec %%cacr,%%d0\n\t"		\
				     "orw %0,%%d0\n\t"			\
				     "movec %%d0,%%cacr"		\
				     : : "di" (FLUSH_I_AND_D) : "d0");	\
    } while (0)

#define flush_cache_all() __flush_cache_all()

extern inline void flush_cache_mm(struct mm_struct *mm)
{
	if (mm == current->mm) __flush_cache_all();
}

extern inline void flush_cache_range(struct mm_struct *mm,
				     unsigned long start,
				     unsigned long end)
{
	if (mm == current->mm){
	    if (m68k_is040or060)
	        cache_push_v(start, end-start);
	    else
	        __flush_cache_030();
	}
}

extern inline void flush_cache_page(struct vm_area_struct *vma,
				    unsigned long vmaddr)
{
	if (vma->vm_mm == current->mm){
	    if (m68k_is040or060)
	        cache_push_v(vmaddr, PAGE_SIZE);
	    else
	        __flush_cache_030();
	}
}

/* Push the page at kernel virtual address and clear the icache */
extern inline void flush_page_to_ram (unsigned long address)
{
    if (m68k_is040or060) {
	register unsigned long tmp __asm ("a0") = VTOP(address);
	__asm__ __volatile__ ("nop\n\t"
			      ".word 0xf470 /* cpushp %%dc,(%0) */\n\t"
			      ".word 0xf490 /* cinvp %%ic,(%0) */"
			      : : "a" (tmp));
    }
    else
	__asm volatile ("movec %%cacr,%%d0\n\t"
			"orw %0,%%d0\n\t"
			"movec %%d0,%%cacr"
			: : "di" (FLUSH_I) : "d0");
}

/* Push n pages at kernel virtual address and clear the icache */
extern inline void flush_pages_to_ram (unsigned long address, int n)
{
    if (m68k_is040or060) {
	while (n--) {
	    register unsigned long tmp __asm ("a0") = VTOP(address);
	    __asm__ __volatile__ ("nop\n\t"
				  ".word 0xf470 /* cpushp %%dc,(%0) */\n\t"
				  ".word 0xf490 /* cinvp %%ic,(%0) */"
				  : : "a" (tmp));
	    address += PAGE_SIZE;
	}
    }
    else
	__asm volatile ("movec %%cacr,%%d0\n\t"
			"orw %0,%%d0\n\t"
			"movec %%d0,%%cacr"
			: : "di" (FLUSH_I) : "d0");
}

/*
 * Check if the addr/len goes up to the end of a physical
 * memory chunk.  Used for DMA functions.
 */
int mm_end_of_chunk (unsigned long addr, int len);

/*
 * Map some physical address range into the kernel address space. The
 * code is copied and adapted from map_chunk().
 */
extern unsigned long kernel_map(unsigned long paddr, unsigned long size,
				int nocacheflag, unsigned long *memavailp );
/*
 * Change the cache mode of some kernel address range.
 */
extern void kernel_set_cachemode( unsigned long address, unsigned long size,
				  unsigned cmode );

/* Values for nocacheflag and cmode */
#define	KERNELMAP_FULL_CACHING		0
#define	KERNELMAP_NOCACHE_SER		1
#define	KERNELMAP_NOCACHE_NONSER	2
#define	KERNELMAP_NO_COPYBACK		3

/*
 * The m68k doesn't have any external MMU info: the kernel page
 * tables contain all the necessary information.
 */
extern inline void update_mmu_cache(struct vm_area_struct * vma,
	unsigned long address, pte_t pte)
{
}

/*
 * I don't know what is going on here, but since these were changed,
 * swapping hasn't been working on the 68040.
 */

#define SWP_TYPE(entry)  (((entry) >> 2) & 0x7f)
#if 0
#define SWP_OFFSET(entry) ((entry) >> 9)
#define SWP_ENTRY(type,offset) (((type) << 2) | ((offset) << 9))
#else
#define SWP_OFFSET(entry) ((entry) >> PAGE_SHIFT)
#define SWP_ENTRY(type,offset) (((type) << 2) | ((offset) << PAGE_SHIFT))
#endif

#endif /* __ASSEMBLY__ */

#endif /* _M68K_PGTABLE_H */