path: root/include/asm-m68k/pgtable.h

#ifndef _M68K_PGTABLE_H
#define _M68K_PGTABLE_H

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

#ifndef __ASSEMBLY__
#include <asm/processor.h>
#include <linux/threads.h>

/*
 * This file contains the functions and defines necessary to modify and use
 * the m68k page table tree.
 */

#include <asm/virtconvert.h>

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


/* PMD_SHIFT determines the size of the area a second-level page table can map */
#define PMD_SHIFT	22
#define PMD_SIZE	(1UL << PMD_SHIFT)
#define PMD_MASK	(~(PMD_SIZE-1))

/* PGDIR_SHIFT determines what a third-level page table entry can map */
#define PGDIR_SHIFT	25
#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
#define PGDIR_MASK	(~(PGDIR_SIZE-1))

/*
 * entries per page directory level: the m68k is configured as three-level,
 * so we do have PMD level physically.
 */
#define PTRS_PER_PTE	1024
#define PTRS_PER_PMD	8
#define PTRS_PER_PGD	128
#define USER_PTRS_PER_PGD	(TASK_SIZE/PGDIR_SIZE)

/* Virtual address region for use by kernel_map() */
#define	KMAP_START	0xd0000000
#define	KMAP_END	0xf0000000

/* Just any arbitrary offset to the start of the vmalloc VM area: the
 * current 8MB value just means that there will be a 8MB "hole" after the
 * physical memory until the kernel virtual memory starts.  That means that
 * any out-of-bounds memory accesses will hopefully be caught.
 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
 * area for the same reason. ;)
 */
#define VMALLOC_OFFSET	(8*1024*1024)
#define VMALLOC_START (((unsigned long) high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
#define VMALLOC_VMADDR(x) ((unsigned long)(x))
#define VMALLOC_END KMAP_START

#endif /* __ASSEMBLY__ */

/*
 * Definitions for MMU descriptors
 */
#define _PAGE_PRESENT	0x001
#define _PAGE_SHORT	0x002
#define _PAGE_RONLY	0x004
#define _PAGE_ACCESSED	0x008
#define _PAGE_DIRTY	0x010
#define _PAGE_SUPER	0x080	/* 68040 supervisor only */
#define _PAGE_FAKE_SUPER 0x200	/* fake supervisor only on 680[23]0 */
#define _PAGE_GLOBAL040	0x400	/* 68040 global bit, used for kva descs */
#define _PAGE_COW	0x800	/* implemented in software */
#define _PAGE_NOCACHE030 0x040	/* 68030 no-cache mode */
#define _PAGE_NOCACHE	0x060	/* 68040 cache mode, non-serialized */
#define _PAGE_NOCACHE_S	0x040	/* 68040 no-cache mode, serialized */
#define _PAGE_CACHE040	0x020	/* 68040 cache mode, cachable, copyback */
#define _PAGE_CACHE040W	0x000	/* 68040 cache mode, cachable, write-through */

/* Page protection values within PTE. */
#define SUN3_PAGE_VALID     (0x80000000)
#define SUN3_PAGE_WRITEABLE (0x40000000)
#define SUN3_PAGE_SYSTEM    (0x20000000)
#define SUN3_PAGE_NOCACHE   (0x10000000)
#define SUN3_PAGE_ACCESSED  (0x02000000)
#define SUN3_PAGE_MODIFIED  (0x01000000)

#define _DESCTYPE_MASK	0x003

#define _CACHEMASK040	(~0x060)
#define _TABLE_MASK	(0xfffffe00)

#define _PAGE_TABLE	(_PAGE_SHORT)
#define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_NOCACHE)

#ifndef __ASSEMBLY__

/* This is the cache mode to be used for pages containing page descriptors for
 * processors >= '040. It is in pte_mknocache(), and the variable is defined
 * and initialized in head.S */
extern int m68k_pgtable_cachemode;

/* This is the cache mode for normal pages, for supervisor access on
 * processors >= '040. It is used in pte_mkcache(), and the variable is
 * defined and initialized in head.S */

#if defined(CONFIG_060_WRITETHROUGH)
extern int m68k_supervisor_cachemode;
#else
#define m68k_supervisor_cachemode _PAGE_CACHE040
#endif

#if defined(CPU_M68040_OR_M68060_ONLY)
#define mm_cachebits _PAGE_CACHE040
#elif defined(CPU_M68020_OR_M68030_ONLY)
#define mm_cachebits 0
#else
extern unsigned long mm_cachebits;
#endif

#define PAGE_NONE	__pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED | mm_cachebits)
#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | mm_cachebits)
#define PAGE_COPY	__pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED | mm_cachebits)
#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED | mm_cachebits)
#define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | _PAGE_DIRTY | _PAGE_ACCESSED | mm_cachebits)

/* Alternate definitions that are compile time constants, for
   initializing protection_map.  The cachebits are fixed later.  */
#define PAGE_NONE_C	__pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED)
#define PAGE_SHARED_C	__pgprot(_PAGE_PRESENT | _PAGE_ACCESSED)
#define PAGE_COPY_C	__pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED)
#define PAGE_READONLY_C	__pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED)

/*
 * The m68k can't do page protection for execute, and considers that the same are read.
 * Also, write permissions imply read permissions. This is the closest we can get..
 */
#define __P000	PAGE_NONE_C
#define __P001	PAGE_READONLY_C
#define __P010	PAGE_COPY_C
#define __P011	PAGE_COPY_C
#define __P100	PAGE_READONLY_C
#define __P101	PAGE_READONLY_C
#define __P110	PAGE_COPY_C
#define __P111	PAGE_COPY_C

#define __S000	PAGE_NONE_C
#define __S001	PAGE_READONLY_C
#define __S010	PAGE_SHARED_C
#define __S011	PAGE_SHARED_C
#define __S100	PAGE_READONLY_C
#define __S101	PAGE_READONLY_C
#define __S110	PAGE_SHARED_C
#define __S111	PAGE_SHARED_C

/* zero page used for uninitialized stuff */
extern unsigned long empty_zero_page;

/*
 * BAD_PAGETABLE is used when we need a bogus page-table, while
 * BAD_PAGE is used for a bogus page.
 *
 * ZERO_PAGE is a global shared page that is always zero: used
 * for zero-mapped memory areas etc..
 */
extern pte_t __bad_page(void);
extern pte_t * __bad_pagetable(void);

#define BAD_PAGETABLE __bad_pagetable()
#define BAD_PAGE __bad_page()
#define ZERO_PAGE(vaddr)	(mem_map + MAP_NR(empty_zero_page))

/* number of bits that fit into a memory pointer */
#define BITS_PER_PTR			(8*sizeof(unsigned long))

/* to align the pointer to a pointer address */
#define PTR_MASK			(~(sizeof(void*)-1))

/* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
/* 64-bit machines, beware!  SRB. */
#define SIZEOF_PTR_LOG2			2

/*
 * Conversion functions: convert a page and protection to a page entry,
 * and a page entry and page directory to the page they refer to.
 */
#define __mk_pte(page, pgprot) \
({									\
	pte_t __pte;							\
									\
	pte_val(__pte) = __pa((void *)page) + pgprot_val(pgprot);	\
	__pte;								\
})
#define mk_pte(page, pgprot) __mk_pte(page_address(page), (pgprot))
#define mk_pte_phys(physpage, pgprot) \
({									\
	pte_t __pte;							\
									\
	pte_val(__pte) = (physpage) + pgprot_val(pgprot);		\
	__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)
{
	unsigned long ptbl = virt_to_phys(ptep) | _PAGE_TABLE | _PAGE_ACCESSED;
	unsigned long *ptr = pmdp->pmd;
	short i = 16;
	while (--i >= 0) {
		*ptr++ = ptbl;
		ptbl += (sizeof(pte_t)*PTRS_PER_PTE/16);
	}
}

extern inline void pgd_set(pgd_t * pgdp, pmd_t * pmdp)
{ pgd_val(*pgdp) = _PAGE_TABLE | _PAGE_ACCESSED | __pa(pmdp); }

#define __pte_page(pte) ((unsigned long)__va(pte_val(pte) & PAGE_MASK))
#define __pmd_page(pmd) ((unsigned long)__va(pmd_val(pmd) & _TABLE_MASK))
#define __pgd_page(pgd) ((unsigned long)__va(pgd_val(pgd) & _TABLE_MASK))

#define pte_none(pte)		(!pte_val(pte))
#define pte_present(pte)	(pte_val(pte) & (_PAGE_PRESENT | _PAGE_FAKE_SUPER))
#define pte_clear(ptep)		({ pte_val(*(ptep)) = 0; })
#define pte_pagenr(pte)		((__pte_page(pte) - PAGE_OFFSET) >> PAGE_SHIFT)

#define pmd_none(pmd)		(!pmd_val(pmd))
#define pmd_bad(pmd)		((pmd_val(pmd) & _DESCTYPE_MASK) != _PAGE_TABLE)
#define pmd_present(pmd)	(pmd_val(pmd) & _PAGE_TABLE)
#define pmd_clear(pmdp) ({			\
	unsigned long *__ptr = pmdp->pmd;	\
	short __i = 16;				\
	while (--__i >= 0)			\
		*__ptr++ = 0;			\
})

#define pgd_none(pgd)		(!pgd_val(pgd))
#define pgd_bad(pgd)		((pgd_val(pgd) & _DESCTYPE_MASK) != _PAGE_TABLE)
#define pgd_present(pgd)	(pgd_val(pgd) & _PAGE_TABLE)
#define pgd_clear(pgdp)		({ pgd_val(*pgdp) = 0; })

/* Permanent address of a page. */
#define page_address(page)	({ if (!(page)->virtual) BUG(); (page)->virtual; })
#define __page_address(page)	(PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT))
#define pte_page(pte)		(mem_map+pte_pagenr(pte))

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

/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */
extern inline int pte_read(pte_t pte)		{ return 1; }
extern inline int pte_write(pte_t pte)		{ return !(pte_val(pte) & _PAGE_RONLY); }
extern inline int pte_exec(pte_t pte)		{ return 1; }
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 pte_t pte_wrprotect(pte_t pte)	{ pte_val(pte) |= _PAGE_RONLY; return pte; }
extern inline pte_t pte_rdprotect(pte_t pte)	{ return pte; }
extern inline pte_t pte_exprotect(pte_t pte)	{ 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_mkwrite(pte_t pte)	{ pte_val(pte) &= ~_PAGE_RONLY; return pte; }
extern inline pte_t pte_mkread(pte_t pte)	{ return pte; }
extern inline pte_t pte_mkexec(pte_t pte)	{ 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_mknocache(pte_t pte)
{
	pte_val(pte) = (pte_val(pte) & _CACHEMASK040) | m68k_pgtable_cachemode;
	return pte;
}
extern inline pte_t pte_mkcache(pte_t pte)	{ pte_val(pte) = (pte_val(pte) & _CACHEMASK040) | m68k_supervisor_cachemode; return pte; }

#define PAGE_DIR_OFFSET(tsk,address) pgd_offset((tsk),(address))

/* 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);
}

#define swapper_pg_dir kernel_pg_dir
extern pgd_t kernel_pg_dir[128];

extern inline pgd_t * pgd_offset_k(unsigned long address)
{
	return kernel_pg_dir + (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 *)__pgd_page(*dir) + ((address >> PMD_SHIFT) & (PTRS_PER_PMD-1));
}

/* Find an entry in the third-level page table.. */ 
extern inline pte_t * pte_offset(pmd_t * pmdp, unsigned long address)
{
	return (pte_t *)__pmd_page(*pmdp) + ((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.
 */

/* Prior to calling these routines, the page should have been flushed
 * from both the cache and ATC, or the CPU might not notice that the
 * cache setting for the page has been changed. -jskov
 */
static inline void nocache_page (unsigned long vaddr)
{
	if (CPU_IS_040_OR_060) {
		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 (CPU_IS_040_OR_060) {
		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);
	}
}


/*
 * Check if the addr/len goes up to the end of a physical
 * memory chunk.  Used for DMA functions.
 */
#ifdef CONFIG_SINGLE_MEMORY_CHUNK
/*
 * It makes no sense to consider whether we cross a memory boundary if
 * we support just one physical chunk of memory.
 */
extern inline int mm_end_of_chunk (unsigned long addr, int len)
{
	return 0;
}
#else
int mm_end_of_chunk (unsigned long addr, int len);
#endif

extern void kernel_set_cachemode(void *addr, unsigned long size, int cmode);

/*
 * 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)
{
}

/* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */
#define SWP_TYPE(x)			(((x).val >> 1) & 0xff)
#define SWP_OFFSET(x)			((x).val >> 10)
#define SWP_ENTRY(type, offset)		((swp_entry_t) { ((type) << 1) | ((offset) << 10) })
#define pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
#define swp_entry_to_pte(x)		((pte_t) { (x).val })

#endif /* __ASSEMBLY__ */

#define module_map      vmalloc
#define module_unmap    vfree

/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
#define PageSkip(page)		(0)
#define kern_addr_valid(addr)	(1)

#define io_remap_page_range remap_page_range

#endif /* _M68K_PGTABLE_H */