text: /*	$OpenBSD: mmu.h,v 1.16 2014/03/29 18:09:29 guenther Exp $ */
  
  /*
   * This file bears almost no resemblance to the original m68k file,
   * so the following copyright notice is questionable, but we are
   * nice people.
   */
  
  /*
   * Copyright (c) 1988 University of Utah.
   * Copyright (c) 1982, 1986, 1990, 1993
   *	The Regents of the University of California.  All rights reserved.
   *
   * This code is derived from software contributed to Berkeley by
   * the Systems Programming Group of the University of Utah Computer
   * Science Department.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   * from: Utah $Hdr: pte.h 1.13 92/01/20$
   *
   *	@(#)pte.h	8.1 (Berkeley) 6/10/93
   */
  
  #ifndef	_M88K_MMU_H_
  #define	_M88K_MMU_H_
  
  /*
   * Parameters which determine the 'geometry' of the m88K page tables in memory.
   */
  
  #define SDT_BITS	10		/* M88K segment table size bits */
  #define PDT_BITS	10		/* M88K page table size bits */
  #define PG_BITS		PAGE_SHIFT	/* M88K hardware page size bits */
  
  /*
   * Common fields for APR, SDT and PTE
   */
  
  /* address frame */
  #define	PG_FRAME	0xfffff000
  #define	PG_SHIFT	PG_BITS
  #define	PG_PFNUM(x)	(((x) & PG_FRAME) >> PG_SHIFT)
  
  /* cache control bits */
  #define	CACHE_DFL	0x00000000
  #define	CACHE_INH	0x00000040	/* cache inhibit */
  #define	CACHE_GLOBAL	0x00000080	/* global scope */
  #define	CACHE_WT	0x00000200	/* write through */
  
  #define	CACHE_MASK	(CACHE_INH | CACHE_GLOBAL | CACHE_WT)
  
  /*
   * Area descriptors
   */
  
  typedef	uint32_t	apr_t;
  
  #define	APR_V		0x00000001	/* valid bit */
  
  /*
   * 88200 PATC (TLB)
   */
  
  #define PATC_ENTRIES	56
  
  /*
   * Segment table entries
   */
  
  typedef uint32_t	sdt_entry_t;
  
  #define	SG_V		0x00000001
  #define	SG_NV		0x00000000
  #define	SG_PROT		0x00000004
  #define	SG_RO		0x00000004
  #define	SG_RW		0x00000000
  #define	SG_SO		0x00000100
  
  #define	SDT_VALID(sdt)	(*(sdt) & SG_V)
  #define	SDT_SUP(sdt)	(*(sdt) & SG_SO)
  #define	SDT_WP(sdt)	(*(sdt) & SG_PROT)
  
  /*
   * Page table entries
   */
  
  typedef uint32_t	pt_entry_t;
  
  #define	PG_V		0x00000001
  #define	PG_NV		0x00000000
  #define	PG_PROT		0x00000004
  #define	PG_U		0x00000008
  #define	PG_M		0x00000010
  #define	PG_M_U		0x00000018
  #define	PG_RO		0x00000004
  #define	PG_RW		0x00000000
  #define	PG_SO		0x00000100
  #define	PG_W		0x00000020	/* XXX unused but reserved field */
  #define	PG_U0		0x00000400	/* U0 bit for M88110 */
  #define	PG_U1		0x00000800	/* U1 bit for M88110 */
  
  #define	PDT_VALID(pte)	(*(pte) & PG_V)
  #define	PDT_SUP(pte)	(*(pte) & PG_SO)
  #define	PDT_WP(pte)	(*(pte) & PG_PROT)
  
  /*
   * Number of entries in a page table.
   */
  
  #define	SDT_ENTRIES	(1<<(SDT_BITS))
  #define PDT_ENTRIES	(1<<(PDT_BITS))
  
  /*
   * Size in bytes of a single page table.
   */
  
  #define SDT_SIZE	(sizeof(sdt_entry_t) * SDT_ENTRIES)
  #define PDT_SIZE	(sizeof(pt_entry_t) * PDT_ENTRIES)
  
  /*
   * Shifts and masks
   */
  
  #define SDT_SHIFT	(PDT_BITS + PG_BITS)
  #define PDT_SHIFT	(PG_BITS)
  
  #define SDT_MASK	(((1 << SDT_BITS) - 1) << SDT_SHIFT)
  #define PDT_MASK	(((1 << PDT_BITS) - 1) << PDT_SHIFT)
  
  #define	SDTIDX(va)	(((va) & SDT_MASK) >> SDT_SHIFT)
  #define	PDTIDX(va)	(((va) & PDT_MASK) >> PDT_SHIFT)
  
  /*
   * BATC entries
   */
  
  #define	BATC_V		0x00000001
  #define	BATC_PROT	0x00000002
  #define	BATC_INH	0x00000004
  #define	BATC_GLOBAL	0x00000008
  #define	BATC_WT		0x00000010
  #define	BATC_SO		0x00000020
  
  typedef uint32_t	batc_t;
  
  /* 8820x fixed size BATC */
  #define	BATC_BLKSHIFT	19
  #define	BATC_BLKBYTES	(1 << BATC_BLKSHIFT)
  #define	BATC_BLKMASK	(BATC_BLKBYTES-1)
  /* number of programmable BATC entries */
  #define	BATC_MAX	8
  
  /* physical and logical block address */
  #define	BATC_PSHIFT	6
  #define	BATC_VSHIFT	19
  
  #define	trunc_batc(a)	((a) & ~BATC_BLKMASK)
  #define	round_batc(a)	trunc_batc((a) + BATC_BLKBYTES - 1)
  
  static pt_entry_t invalidate_pte(pt_entry_t *);
  static __inline__ pt_entry_t
  invalidate_pte(pt_entry_t *pte)
  {
  	pt_entry_t oldpte;
  
  	oldpte = PG_NV;
  	__asm__ volatile
  	    ("xmem %0, %2, %%r0" : "+r"(oldpte), "+m"(*pte) : "r"(pte));
  	return oldpte;
  }
  
  #endif /* __M88K_MMU_H__ */
  