pmap.h revision 1.12 1 /* $NetBSD: pmap.h,v 1.12 2001/07/29 12:45:27 chris Exp $ */
2
3 /*
4 * Copyright (c) 1994,1995 Mark Brinicombe.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by Mark Brinicombe
18 * 4. The name of the author may not be used to endorse or promote products
19 * derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #ifndef _ARM32_PMAP_H_
34 #define _ARM32_PMAP_H_
35
36 #include <machine/cpufunc.h>
37 #include <machine/pte.h>
38 #include <uvm/uvm_object.h>
39
40 /*
41 * a pmap describes a processes' 4GB virtual address space. this
42 * virtual address space can be broken up into 4096 1MB regions which
43 * are described by PDEs in the PDP. the PDEs are defined as follows:
44 *
45 * (ranges are inclusive -> exclusive, just like vm_map_entry start/end)
46 * (the following assumes that KERNBASE is 0xf0000000)
47 *
48 * PDE#s VA range usage
49 * 0->3835 0x0 -> 0xefc00000 user address space
50 * 3836->3839 0xefc00000-> recursive mapping of PDP (used for
51 * 0xf0000000 linear mapping of PTPs)
52 * 3840->3851 0xf0000000-> kernel text address space (constant
53 * 0xf0c00000 across all pmap's/processes)
54 * 3852->3855 0xf0c00000-> "alternate" recursive PDP mapping
55 * 0xf1000000 (for other pmaps)
56 * 3856->4095 0xf1000000-> KVM and device mappings, constant
57 * 0x00000000 across all pmaps
58 *
59 * The maths works out that to then map each 1MB block into 4k pages requires
60 * 256 entries, of 4 bytes each, totaling 1k per 1MB. However as we use 4k
61 * pages we allocate 4 PDE's at a time, allocating the same access permissions
62 * to them all. This means we only need 1024 entries in the page table page
63 * table, IE we use 1 4k page to linearly map all the other page tables used.
64 */
65
66 /*
67 * Data structures used by pmap
68 */
69
70 /*
71 * Structure that describes a Level 1 page table and the flags
72 * associated with it.
73 */
74 struct l1pt {
75 SIMPLEQ_ENTRY(l1pt) pt_queue; /* Queue pointers */
76 struct pglist pt_plist; /* Allocated page list */
77 vaddr_t pt_va; /* Allocated virtual address */
78 int pt_flags; /* Flags */
79 };
80 #define PTFLAG_STATIC 1 /* Statically allocated */
81 #define PTFLAG_KPT 2 /* Kernel pt's are mapped */
82 #define PTFLAG_CLEAN 4 /* L1 is clean */
83
84 /*
85 * The pmap structure itself.
86 */
87 struct pmap {
88 struct uvm_object pm_obj; /* uvm_object */
89 #define pm_lock pm_obj.vmobjlock
90 pd_entry_t *pm_pdir; /* KVA of page directory */
91 struct l1pt *pm_l1pt; /* L1 descriptor */
92 paddr_t pm_pptpt; /* PA of pt's page table */
93 vaddr_t pm_vptpt; /* VA of pt's page table */
94 struct pmap_statistics pm_stats; /* pmap statistics */
95 };
96
97 typedef struct pmap *pmap_t;
98
99 /*
100 * For each struct vm_page, there is a list of all currently valid virtual
101 * mappings of that page. An entry is a pv_entry_t, the list is pv_table.
102 */
103 typedef struct pv_entry {
104 struct pv_entry *pv_next; /* next pv_entry */
105 struct pmap *pv_pmap; /* pmap where mapping lies */
106 vaddr_t pv_va; /* virtual address for mapping */
107 int pv_flags; /* flags */
108 } *pv_entry_t;
109
110 /*
111 * A pv_page_info struture looks like this. It is used to contain status
112 * information for pv_entry freelists.
113 */
114 struct pv_page;
115
116 struct pv_page_info {
117 TAILQ_ENTRY(pv_page) pgi_list;
118 struct pv_entry *pgi_freelist;
119 int pgi_nfree;
120 };
121
122 /*
123 * A pv_page itself looks like this. pv_entries are requested from the VM a
124 * pv_page at a time.
125 *
126 * We also define a macro that states the number of pv_entries per page
127 * allocated.
128 */
129 #define NPVPPG ((NBPG - sizeof(struct pv_page_info)) / sizeof(struct pv_entry))
130
131 struct pv_page {
132 struct pv_page_info pvp_pgi;
133 struct pv_entry pvp_pv[NPVPPG];
134 };
135
136 /*
137 * Page hooks. I'll eliminate these sometime soon :-)
138 *
139 * For speed we store the both the virtual address and the page table
140 * entry address for each page hook.
141 */
142 typedef struct {
143 vaddr_t va;
144 pt_entry_t *pte;
145 } pagehook_t;
146
147 /*
148 * Physical / virtual address structure. In a number of places (particularly
149 * during bootstrapping) we need to keep track of the physical and virtual
150 * addresses of various pages
151 */
152 typedef struct {
153 paddr_t pv_pa;
154 vaddr_t pv_va;
155 } pv_addr_t;
156
157 /*
158 * _KERNEL specific macros, functions and prototypes
159 */
160
161 #ifdef _KERNEL
162
163 /*
164 * Commonly referenced structures
165 */
166 extern pv_entry_t pv_table; /* Phys to virt mappings, per page. */
167 extern struct pmap kernel_pmap_store;
168 extern int pmap_debug_level; /* Only exists if PMAP_DEBUG */
169
170 /*
171 * Macros that we need to export
172 */
173 #define pmap_kernel() (&kernel_pmap_store)
174 #define pmap_update() /* nothing (yet) */
175 #define pmap_resident_count(pmap) ((pmap)->pm_stats.resident_count)
176 #define pmap_wired_count(pmap) ((pmap)->pm_stats.wired_count)
177
178 #define pmap_phys_address(ppn) (arm_page_to_byte((ppn)))
179
180 /*
181 * Functions that we need to export
182 */
183 extern boolean_t pmap_testbit __P((paddr_t, int));
184 extern void pmap_changebit __P((paddr_t, int, int));
185 extern vaddr_t pmap_map __P((vaddr_t, vaddr_t, vaddr_t, int));
186 extern void pmap_procwr __P((struct proc *, vaddr_t, int));
187 #define PMAP_NEED_PROCWR
188
189 /*
190 * Functions we use internally
191 */
192 extern void pmap_bootstrap __P((pd_entry_t *, pv_addr_t));
193 extern void pmap_debug __P((int));
194 extern int pmap_handled_emulation __P((struct pmap *, vaddr_t));
195 extern int pmap_modified_emulation __P((struct pmap *, vaddr_t));
196 extern void pmap_postinit __P((void));
197 extern pt_entry_t *pmap_pte __P((struct pmap *, vaddr_t));
198
199 #endif /* _KERNEL */
200
201 /*
202 * Useful macros and constants
203 */
204
205 /* Virtual address to page table entry */
206 #define vtopte(va) \
207 ((pt_entry_t *)(PROCESS_PAGE_TBLS_BASE + \
208 (arm_byte_to_page((unsigned int)(va)) << 2)))
209
210 /* Virtual address to physical address */
211 #define vtophys(va) \
212 ((*vtopte(va) & PG_FRAME) | ((unsigned int)(va) & ~PG_FRAME))
213
214 /* L1 and L2 page table macros */
215 #define pmap_pde(m, v) (&((m)->pm_pdir[((vaddr_t)(v) >> PDSHIFT)&4095]))
216 #define pmap_pte_pa(pte) (*(pte) & PG_FRAME)
217 #define pmap_pde_v(pde) (*(pde) != 0)
218 #define pmap_pte_v(pte) (*(pte) != 0)
219
220 /* Size of the kernel part of the L1 page table */
221 #define KERNEL_PD_SIZE \
222 (PD_SIZE - (KERNEL_SPACE_START >> PDSHIFT) * sizeof(pd_entry_t))
223
224 #endif /* _ARM32_PMAP_H_ */
225