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      1 /*	$NetBSD: mmu_30.h,v 1.3 2025/07/08 11:45:25 thorpej Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2023 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #ifndef _M68K_MMU_30_H_
     33 #define	_M68K_MMU_30_H_
     34 
     35 #include <machine/fcode.h>
     36 
     37 /*
     38  * The built-in MMU in the 68030 is a subset of the 68851.  Section 9.6
     39  * of the 68030 User's Manual describes the differences:
     40  *
     41  * The following 68851 functions are not present on the 68030:
     42  * - Access levels
     43  * - Breakpoint registers
     44  * - DMA Root Pointer
     45  * - Task aliases
     46  * - Lockable ATC entries
     47  * - ATC entries defined as Shared Globally
     48  *
     49  * Furthermore, the 68030 has some functional differences:
     50  * - Only 22 ATC entries
     51  * - Reduced instruction set for MMU operations
     52  * - Reduced addressing modes for MMU instructions.
     53  *
     54  * Instructions removed: PVALID, PFLUSHR, PFLUSHS, PBcc, PDBcc, PScc,
     55  * PTRAPcc, PSAVE, PRESTORE.
     56  *
     57  * Registers removed: CAL, VAL, BAD, BACx, DRP, AC.
     58  *
     59  * The 68030 does, however, add a pair of Transparent Translation
     60  * registers
     61  */
     62 
     63 /*
     64  * 9.7.3 -- Transparent Translation registers
     65  *
     66  * These registers define blocks of logical address space that are
     67  * transparently translated VA==PA.  The minimum block size is 16MB,
     68  * and the blocks may overlap.  The mode in which the transparent
     69  * translation is applied is specified by the Function Code base and
     70  * mask fields.
     71  *
     72  * The Logical Address Base specifies the address of the block and
     73  * the Logical Address Mask field specifies the address bits to *ignore*.
     74  *
     75  */
     76 #define	TT30_LAB	__BITS(31,24)	/* Logical Address Base */
     77 #define	TT30_LAM	__BITS(16,23)	/* Logical Address Mask */
     78 #define	TT30_E		__BIT(15)	/* Enable transparent translation */
     79 #define	TT30_CI		__BIT(10)	/* Cache Inhibit */
     80 #define	TT30_RW		__BIT(9)	/* Read(1) or Write(0) translated */
     81 #define	TT30_RWM	__BIT(8)	/* RW field used(0) or ignored(1) */
     82 #define	TT30_FCBASE	__BITS(4,6)	/* Function Code base */
     83 #define	TT30_FCMASK	__BITS(0,2)	/* Function Code bits to ignore */
     84 
     85 /* Convenience definitions for address space selection. */
     86 #define	TT30_USERD	__SHIFTIN(FC_USERD,TT30_FCBASE)
     87 #define	TT30_USERP	__SHIFTIN(FC_USERP,TT30_FCBASE)
     88 #define	TT30_SUPERD	__SHIFTIN(FC_SUPERD,TT30_FCBASE)
     89 #define	TT30_SUPERP	__SHIFTIN(FC_SUPERP,TT30_FCBASE)
     90 
     91 #ifdef _KERNEL
     92 /*
     93  * TT register value indices in the mmu_ttregs[] array.  Note that asm
     94  * code makes assumptions about these indices, to change them at your
     95  * peril.
     96  */
     97 extern uint32_t mmu_tt30[];
     98 #define	MMU_TTREG_TT0	0
     99 #define	MMU_TTREG_TT1	1
    100 #define	MMU_NTTREGS30	2
    101 
    102 void	mmu_load_tt30(uint32_t *);
    103 #endif /* _KERNEL */
    104 
    105 #endif /* _M68K_MMU_30_H_ */
    106