1
2 #define _SYSTEM 1
3
4 #include <minix/com.h>
5 #include <minix/callnr.h>
6 #include <minix/type.h>
7 #include <minix/config.h>
8 #include <minix/const.h>
9 #include <minix/sysutil.h>
10 #include <minix/syslib.h>
11 #include <minix/debug.h>
12 #include <minix/bitmap.h>
13 #include <minix/hash.h>
14
15 #include <sys/mman.h>
16
17 #include <limits.h>
18 #include <string.h>
19 #include <errno.h>
20 #include <assert.h>
21 #include <stdint.h>
22 #include <sys/param.h>
23
24 #include "vm.h"
25 #include "proto.h"
26 #include "util.h"
27 #include "glo.h"
28 #include "region.h"
29 #include "sanitycheck.h"
30 #include "memlist.h"
31
pb_new(phys_bytes phys)32 struct phys_block *pb_new(phys_bytes phys)
33 {
34 struct phys_block *newpb;
35
36 if(!SLABALLOC(newpb)) {
37 printf("vm: pb_new: couldn't allocate phys block\n");
38 return NULL;
39 }
40
41 if(phys != MAP_NONE)
42 assert(!(phys % VM_PAGE_SIZE));
43
44 USE(newpb,
45 newpb->phys = phys;
46 newpb->refcount = 0;
47 newpb->firstregion = NULL;
48 newpb->flags = 0;
49 );
50
51 return newpb;
52 }
53
pb_free(struct phys_block * pb)54 void pb_free(struct phys_block *pb)
55 {
56 if(pb->phys != MAP_NONE)
57 free_mem(ABS2CLICK(pb->phys), 1);
58 SLABFREE(pb);
59 }
60
pb_link(struct phys_region * newphysr,struct phys_block * newpb,vir_bytes offset,struct vir_region * parent)61 void pb_link(struct phys_region *newphysr, struct phys_block *newpb,
62 vir_bytes offset, struct vir_region *parent)
63 {
64 USE(newphysr,
65 newphysr->offset = offset;
66 newphysr->ph = newpb;
67 newphysr->parent = parent;
68 newphysr->next_ph_list = newpb->firstregion;
69 newpb->firstregion = newphysr;);
70 newpb->refcount++;
71 }
72
pb_reference(struct phys_block * newpb,vir_bytes offset,struct vir_region * region,mem_type_t * memtype)73 struct phys_region *pb_reference(struct phys_block *newpb,
74 vir_bytes offset, struct vir_region *region, mem_type_t *memtype)
75 {
76 struct phys_region *newphysr;
77
78 if(!SLABALLOC(newphysr)) {
79 printf("vm: pb_reference: couldn't allocate phys region\n");
80 return NULL;
81 }
82
83 newphysr->memtype = memtype;
84
85 /* New physical region. */
86 pb_link(newphysr, newpb, offset, region);
87
88 physblock_set(region, offset, newphysr);
89
90 return newphysr;
91 }
92
93 /*===========================================================================*
94 * pb_unreferenced *
95 *===========================================================================*/
pb_unreferenced(struct vir_region * region,struct phys_region * pr,int rm)96 void pb_unreferenced(struct vir_region *region, struct phys_region *pr, int rm)
97 {
98 struct phys_block *pb;
99
100 pb = pr->ph;
101 assert(pb->refcount > 0);
102 USE(pb, pb->refcount--;);
103 /* assert(pb->refcount >= 0); */ /* always true */
104
105 if(pb->firstregion == pr) {
106 USE(pb, pb->firstregion = pr->next_ph_list;);
107 } else {
108 struct phys_region *others;
109
110 for(others = pb->firstregion; others;
111 others = others->next_ph_list) {
112 assert(others->ph == pb);
113 if(others->next_ph_list == pr) {
114 USE(others, others->next_ph_list = pr->next_ph_list;);
115 break;
116 }
117 }
118
119 assert(others); /* Otherwise, wasn't on the list. */
120 }
121
122 if(pb->refcount == 0) {
123 assert(!pb->firstregion);
124 int r;
125 if((r = pr->memtype->ev_unreference(pr)) != OK)
126 panic("unref failed, %d", r);
127
128 SLABFREE(pb);
129 }
130
131 pr->ph = NULL;
132
133 if(rm) physblock_set(region, pr->offset, NULL);
134 }
135
mem_cow(struct vir_region * region,struct phys_region * ph,phys_bytes new_page_cl,phys_bytes new_page)136 int mem_cow(struct vir_region *region,
137 struct phys_region *ph, phys_bytes new_page_cl, phys_bytes new_page)
138 {
139 struct phys_block *pb;
140
141 if(new_page == MAP_NONE) {
142 u32_t allocflags;
143 allocflags = vrallocflags(region->flags);
144
145 if((new_page_cl = alloc_mem(1, allocflags)) == NO_MEM)
146 return ENOMEM;
147
148 new_page = CLICK2ABS(new_page_cl);
149 }
150
151 assert(ph->ph->phys != MAP_NONE);
152
153 if(sys_abscopy(ph->ph->phys, new_page, VM_PAGE_SIZE) != OK) {
154 panic("VM: abscopy failed\n");
155 return EFAULT;
156 }
157
158 if(!(pb = pb_new(new_page))) {
159 free_mem(new_page_cl, 1);
160 return ENOMEM;
161 }
162
163 pb_unreferenced(region, ph, 0);
164 pb_link(ph, pb, ph->offset, region);
165 ph->memtype = &mem_type_anon;
166
167 return OK;
168 }
169