xref: /netbsd-src/sys/arch/m68k/include/mmu_51.h (revision a5175f1e986253dff5bbe596a6ad8c22a091e4b6)
1 /*	$NetBSD: mmu_51.h,v 1.4 2024/02/08 20:11:56 andvar Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997, 2023 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jeremy Cooper and 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_51_H_
33 #define	_M68K_MMU_51_H_
34 
35 /*
36  * Translation table structures for the 68851 MMU.
37  *
38  * The 68851 MMU (as well as the 68030's built-in MMU) are pretty flexible and
39  * can use a 1, 2, 3, or 4-level tree structure and a number of page sizes.
40  *
41  * The logical address format is defined as:
42  *
43  *  31                                                                0
44  * |        |          |          |          |          |              |
45  *  SSSSSSSS AAAAAAAAAA BBBBBBBBBB CCCCCCCCCC DDDDDDDDDD PPPPPPPPPPPPPP
46  *  Initial   A Index    B Index    C Index    D Index    Page Offset
47  *   Shift
48  *
49  * The Initial Shift, and number of A, B, C, and D index bits are defined
50  * in the Translation Control register.  Once the MMU encounters a tree
51  * level where the number of index bits is 0, tree traversal stops.  The
52  * values of IS + TIA + TIB + TIC + TID + page offset must equal 32.  For
53  * example, for a 2-level arrangment using 4KB pages where all 32-bits of
54  * the address are significant:
55  *
56  *     IS  TIA  TIB  TIC  TID  page
57  *	0 + 10 + 10 +  0 +  0 +  12 == 32
58  */
59 
60 /*
61  * The 68851 has 3 descriptor formats:
62  *
63  *	Long Table Descriptors		(8 byte)
64  *	Short Table Descriptors		(4 byte)
65  *	Page Descriptors		(4 byte)
66  *
67  * These occupy the lower 2 bits of each descriptor and the root pointers.
68  */
69 #define	DT51_INVALID	0
70 #define	DT51_PAGE	1	/* points to a page */
71 #define	DT51_SHORT	2	/* points to a short entry table */
72 #define	DT51_LONG	3	/* points to a long entry table */
73 
74 /*
75  * Long Format Table Descriptor
76  *
77  *  63                                                             48
78  *  +---+---.---.---.---.---.---.---.---.---.---.---.---.---.---.---+
79  *  |L/U|                 LIMIT                                     |
80  *  +---+---.---+---.---.---+---+---+---+---+---+---+---+---+---.---+
81  *  |    RAL    |    WAL    |SG | S | 0 | 0 | 0 | 0 | U |WP |  DT   |
82  *  +---.---.---+---.---.---+---+---+---+---+---+---+---+---+---.---+
83  *  |              TABLE PHYSICAL ADDRESS (BITS 31-16)              |
84  *  +---.---.---.---.---.---.---.---.---.---.---.---+---.---.---.---+
85  *  |       TABLE PHYSICAL ADDRESS (15-4)           |     UNUSED    |
86  *  +---.---.---.---.---.---.---.---.---.---.---.---+---.---.---.---+
87  *  15                                                              0
88  *
89  * DT is either 2 or 3, depending on what next table descriptor format is.
90  */
91 struct mmu51_ldte {		/* 'dte' stands for 'descriptor table entry' */
92 	uint32_t	ldte_attr;
93 	uint32_t	ldte_addr;
94 };
95 #define	DTE51_ADDR	__BITS(4,31)	/* table address mask */
96 #define	DTE51_LOWER	__BIT(31)	/* L: Index limit is lower limit */
97 #define	DTE51_LIMIT	__BITS(16,30)	/* L: Index limit */
98 #define	DTE51_RAL	__BITS(13,15)	/* L: Read Access Level */
99 #define	DTE51_WAL	__BITS(10,12)	/* L: Write Access Level */
100 #define	DTE51_SG	__BIT(9)	/* L: Shared Globally */
101 #define	DTE51_S		__BIT(8)	/* L: Supervisor protected */
102 #define	DTE51_U		__BIT(3)	/* Used */
103 #define	DTE51_WP	__BIT(2)	/* Write Protected */
104 
105 /*
106  * Short Format Table Descriptor
107  *
108  * 31                                                             16
109  * +---.---.---.---.---.---.---.---.---.---.---.---.---.---.---.---+
110  * |           TABLE PHYSICAL BASE ADDRESS (BITS 31-16)            |
111  * +---.---.---.---.---.---.---.---.---.---.---.---+---+---+---.---+
112  * | TABLE PHYSICAL BASE ADDRESS (15-4)            | U |WP |  DT   |
113  * +---.---.---.---.---.---.---.---.---.---.---.---+---+---+---.---+
114  * 15                                                              0
115  *
116  * DT is either 2 or 3, depending on what next table descriptor format is.
117  */
118 
119 /*
120  * Long Format Page Descriptor (Level A table only)
121  *
122  *  63                                                             48
123  *  +---.---.---.---.---.---.---.---.---.---.---.---.---.---.---.---+
124  *  |                          UNUSED                               |
125  *  +---.---.---+---.---.---+---+---+---+---+---+---+---+---+---.---+
126  *  |    RAL    |    WAL    |SG | S | G |CI | L | M | U |WP |DT (01)|
127  *  +---.---.---+---.---.---+---+---+---+---+---+---+---+---+---.---+
128  *  |               PAGE PHYSICAL ADDRESS (BITS 31-16)              |
129  *  +---.---.---.---.---.---.---.---.---.---.---.---.---.---.---.---+
130  *  | PAGE PHYS. ADDRESS (15-8)     |            UNUSED             |
131  *  +---.---.---.---.---.---.---.---.---.---.---.---.---.---.---.---+
132  *  15                                                              0
133  *
134  * N.B. Unused bits of the page address (if the page size is larger
135  * than 256 bytes) can be used as software-defined PTE bits.
136  */
137 struct mmu51_lpte {		/* 'pte' stands for 'page table entry' */
138 	uint32_t	lpte_attr;
139 	uint32_t	lpte_addr;
140 };
141 #define	PTE51_ADDR	__BITS(8,31)	/* page address mask */
142 #define	PTE51_RAL	__BITS(13,15)	/* L: Read Access Level */
143 #define	PTE51_WAL	__BITS(10,12)	/* L: Write Access Level */
144 #define	PTE51_SG	__BIT(9)	/* L: Shared Globally */
145 #define	PTE51_S		__BIT(8)	/* L: Supervisor protected */
146 #define	PTE51_G		__BIT(7)	/* Gate allowed */
147 #define	PTE51_CI	__BIT(6)	/* Cache inhibit */
148 #define	PTE51_L		__BIT(5)	/* Lock entry */
149 #define	PTE51_M		__BIT(4)	/* Modified */
150 #define	PTE51_U		__BIT(3)	/* Used */
151 #define	PTE51_WP	__BIT(2)	/* Write Protected */
152 
153 /*
154  * Short Format Page Descriptor
155  *
156  * 31                                                             16
157  * +---.---.---.---.---.---.---.---.---.---.---.---.---.---.---.---+
158  * |            PAGE PHYSICAL BASE ADDRESS (BITS 31-16)            |
159  * +---.---.---.---.---.---.---.---+---+---+---+---+---+---+---.---+
160  * | PAGE PHYS. BASE ADDRESS (15-8)| G |CI | L | M | U |WP |DT (01)|
161  * +---.---.---.---.---.---.---.---+---+---+---+---+---+---+---.---+
162  * 15                                                              0
163  *
164  * N.B. Unused bits of the page address (if the page size is larger
165  * than 256 bytes) can be used as software-defined PTE bits.
166  */
167 
168 /*
169  * MMU registers (and the sections in the 68851 manual that
170  * describe them).
171  */
172 
173 /*
174  * 5.1.4 -- Root Pointer
175  * (and also 6.1.1)
176  *
177  * This is a 64-bit register.  The upper 32 bits contain configuration
178  * information, and the lower 32 bits contain the A table address.
179  * Bits 3-0 of the address must be 0.  The root pointer is essentially
180  * a long format table descriptor with only the U/L, limit, and SG bits.
181  *
182  * The 68851 has 3 root pointers:
183  *
184  * CRP		CPU root pointer, for user accesses
185  * SRP		Supervisor root pointer
186  * DRP		DMA root pointer, for IOMMU functionality (not on '030)
187  *
188  * Selection of root pointer is as follows:
189  *
190  *	FC3	FC2	SRE		Root pointer used
191  *	 0	 0	 0		      CRP
192  *	 0	 0	 1		      CRP
193  *	 0	 1	 0		      CRP
194  *	 0	 1	 1		      SRP
195  *	 1	 x	 x		      DRP
196  */
197 struct mmu51_rootptr {
198 	unsigned long	rp_attr;	/* Lower/Upper Limit and access flags */
199 	unsigned long	rp_addr;	/* Physical Base Address */
200 };
201 
202 /*
203  * 6.1.2 -- PMMU Cache Status (PCSR) (16-bit)
204  */
205 #define	PCSR51_F	__BIT(15)	/* Flush(ed) */
206 #define	PCSR51_LW	__BIT(14)	/* Lock Warning */
207 #define	PCSR51_TA	__BITS(0,2)	/* Task Alias (not '030) */
208 
209 /*
210  * 6.1.3 -- Translation Control (TCR) (32-bit)
211  */
212 #define	TCR51_E		__BIT(31)	/* Enable translation */
213 #define	TCR51_SRE	__BIT(25)	/* Supervisor Root Enable */
214 #define	TCR51_FCL	__BIT(24)	/* Function Code Lookup */
215 #define	TCR51_PS	__BITS(20,23)	/* Page Size (see below) */
216 #define	TCR51_IS	__BITS(16,19)	/* Initial Shift */
217 #define	TCR51_TIA	__BITS(12,15)	/* Table A Index bits */
218 #define	TCR51_TIB	__BITS(8,11)	/* Table B Index bits */
219 #define	TCR51_TIC	__BITS(4,7)	/* Table C Index bits */
220 #define	TCR51_TID	__BITS(0,3)	/* Table D Index bits */
221 
222 /*
223  * Astute readers will note that the value in the PS field is
224  * log2(PAGE_SIZE).
225  */
226 #define	TCR51_PS_256	__SHIFTIN(0x8, TCR51_PS)
227 #define	TCR51_PS_512	__SHIFTIN(0x9, TCR51_PS)
228 #define	TCR51_PS_1K	__SHIFTIN(0xa, TCR51_PS)
229 #define	TCR51_PS_2K	__SHIFTIN(0xb, TCR51_PS)
230 #define	TCR51_PS_4K	__SHIFTIN(0xc, TCR51_PS)
231 #define	TCR51_PS_8K	__SHIFTIN(0xd, TCR51_PS)
232 #define	TCR51_PS_16K	__SHIFTIN(0xe, TCR51_PS)
233 #define	TCR51_PS_32K	__SHIFTIN(0xf, TCR51_PS)
234 
235 /*
236  * 6.1.4 -- Current Access Level (8-bit)
237  * 6.1.5 -- Validate Access Level
238  */
239 #define	CAL51_AL	__BITS(5,7)
240 
241 /*
242  * 6.1.6 -- Stack Change Control (8-bit)
243  */
244 
245 /*
246  * 6.1.7 -- Access Control (16-bit)
247  */
248 #define	AC51_MC		__BIT(7)	/* Module Control */
249 #define	AC51_ALC	__BITS(4,5)	/* Access Level Control */
250 #define	AC51_MDS	__BITS(0,1)	/* Module Descriptor Size */
251 
252 /*
253  * 6.1.8 -- PMMU Status Register (PSR) (16-bit)
254  */
255 #define	PSR51_B		__BIT(15)	/* Bus Error */
256 #define	PSR51_L		__BIT(14)	/* Limit Violation */
257 #define	PSR51_S		__BIT(13)	/* Supervisor Violation */
258 #define	PSR51_A		__BIT(12)	/* Access Level Violation */
259 #define	PSR51_W		__BIT(11)	/* Write Protected */
260 #define	PSR51_I		__BIT(10)	/* Invalid */
261 #define	PSR51_M		__BIT(9)	/* Modified */
262 #define	PSR51_G		__BIT(8)	/* Gate */
263 #define	PSR51_C		__BIT(7)	/* Globally Shareable */
264 #define	PSR51_N		__BITS(0,2)	/* Number of levels */
265 
266 #ifdef _KERNEL
267 extern unsigned int protorp[2];
268 
269 void	mmu_load_urp51(paddr_t);
270 void	mmu_load_urp20hp(paddr_t);	/* for convenience */
271 #endif /* _KERNEL */
272 
273 #endif /* _M68K_MMU_51_H_ */
274