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 */
97extern uint32_t mmu_tt30[];
98#define MMU_TTREG_TT0 0
99#define MMU_TTREG_TT1 1
100#define MMU_NTTREGS30 2
101
102void mmu_load_tt30(uint32_t *);
103#endif /* _KERNEL */
104
105#endif /* _M68K_MMU_30_H_ */