xref: /openbsd-src/sys/arch/riscv64/include/vmparam.h (revision 975217253947622c32c832a3f219d28791e91461)
1 /*	$OpenBSD: vmparam.h,v 1.9 2023/11/28 09:10:18 jsg Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * William Jolitz.
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  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)vmparam.h	5.9 (Berkeley) 5/12/91
35  */
36 
37 #ifndef _MACHINE_VMPARAM_H_
38 #define _MACHINE_VMPARAM_H_
39 
40 /*
41  * Machine dependent constants for riscv64.
42  */
43 
44 #define	USRSTACK	VM_MAXUSER_ADDRESS
45 
46 /*
47  * Virtual memory related constants, all in bytes
48  */
49 #ifndef MAXTSIZ
50 #define	MAXTSIZ		((paddr_t)1*1024*1024*1024)	/* max text size */
51 #endif
52 #ifndef DFLDSIZ
53 #define	DFLDSIZ		((paddr_t)128*1024*1024)	/* initial data size limit */
54 #endif
55 #ifndef MAXDSIZ
56 #define	MAXDSIZ		((paddr_t)16*1024*1024*1024)	/* max data size */
57 #endif
58 #ifndef BRKSIZ
59 #define	BRKSIZ		((paddr_t)1*1024*1024*1024)	/* heap gap size */
60 #endif
61 #ifndef	DFLSSIZ
62 #define	DFLSSIZ		((paddr_t)128*1024*1024)	/* initial stack size limit */
63 #endif
64 #ifndef	MAXSSIZ
65 #define	MAXSSIZ		((paddr_t)1*1024*1024*1024)	/* max stack size */
66 #endif
67 
68 #define	STACKGAP_RANDOM	256*1024
69 
70 /*
71  * Size of shared memory map
72  */
73 #ifndef	SHMMAXPGS
74 #define	SHMMAXPGS	1024
75 #endif
76 
77 /*
78  * Size of User Raw I/O map
79  */
80 #define	USRIOSIZE	300
81 
82 /**
83  * Address space layout.
84  *
85  * RISC-V implements multiple paging modes with different virtual address space
86  * sizes: SV32, SV39 and SV48.  SV39 permits a virtual address space size of
87  * 512GB and uses a three-level page table.  Since this is large enough for most
88  * purposes, we currently use SV39 for both userland and the kernel, avoiding
89  * the extra translation step required by SV48.
90  *
91  * The address space is split into two regions at each end of the 64-bit address
92  * space:
93  *
94  * 0x0000000000000000 - 0x0000003fffffffff    256GB user map
95  * 0x0000004000000000 - 0xffffffbfffffffff    unmappable
96  * 0xffffffc000000000 - 0xffffffc7ffffffff    32GB kernel map
97  * 0xffffffc800000000 - 0xffffffcfffffffff    32GB unused
98  * 0xffffffd000000000 - 0xffffffefffffffff    128GB direct map
99  * 0xfffffff000000000 - 0xffffffffffffffff    64GB unused
100  *
101  * The kernel is loaded at the beginning of the kernel map.
102  *
103  * We define some interesting address constants:
104  *
105  * VM_MIN_ADDRESS and VM_MAX_ADDRESS define the start and end of the entire
106  * 64 bit address space, mostly just for convenience.
107  *
108  * VM_MIN_KERNEL_ADDRESS and VM_MAX_KERNEL_ADDRESS define the start and end of
109  * mappable kernel virtual address space.
110  *
111  * VM_MIN_ADDRESS and VM_MAXUSER_ADDRESS define the start and end of the
112  * user address space.
113  */
114 #define	VM_MIN_ADDRESS		((vaddr_t)PAGE_SIZE)
115 #define	VM_MAX_ADDRESS		(0xffffffffffffffffUL)
116 
117 #define	VM_MIN_KERNEL_ADDRESS	(0xffffffc000000000UL)
118 #define	VM_MAX_KERNEL_ADDRESS	(0xffffffc800000000UL)
119 
120 /* Kernel L1 Page Table Range */
121 #define	L1_KERN_BASE		(256)
122 #define	L1_KERN_ENTRIES		(288 - L1_KERN_BASE)
123 
124 #define	DMAP_MIN_ADDRESS	(0xffffffd000000000UL)
125 #define	DMAP_MAX_ADDRESS	(0xfffffff000000000UL)
126 
127 /* DMAP L1 Page Table Range */
128 #define	L1_DMAP_BASE		(320)
129 #define	L1_DMAP_ENTRIES		(448 - L1_DMAP_BASE)
130 
131 #define	VM_MAXUSER_ADDRESS	(0x0000004000000000UL)  /* 39 bits */
132 
133 #ifdef _KERNEL
134 #define	VM_MIN_STACK_ADDRESS	(VM_MAXUSER_ADDRESS * 3 / 4)
135 #endif
136 
137 #define	KERNBASE		(VM_MIN_KERNEL_ADDRESS)
138 
139 #ifndef _LOCORE
140 extern paddr_t dmap_phys_base;
141 #endif
142 
143 /* virtual sizes (bytes) for various kernel submaps */
144 #define	VM_PHYS_SIZE		(USRIOSIZE*PAGE_SIZE)
145 
146 #define	VM_PHYSSEG_MAX		32
147 #define	VM_PHYSSEG_STRAT	VM_PSTRAT_BSEARCH
148 #define	VM_PHYSSEG_NOADD	/* can't add RAM after vm_mem_init */
149 
150 #endif /* _MACHINE_VMPARAM_H_ */
151