Merge branches 'x86/prototypes', 'x86/x2apic' and 'x86/debug' into x86/core
[linux-2.6] / arch / um / kernel / physmem.c
1 /*
2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3  * Licensed under the GPL
4  */
5
6 #include "linux/bootmem.h"
7 #include "linux/mm.h"
8 #include "linux/pfn.h"
9 #include "asm/page.h"
10 #include "as-layout.h"
11 #include "init.h"
12 #include "kern.h"
13 #include "mem_user.h"
14 #include "os.h"
15
16 static int physmem_fd = -1;
17
18 /* Changed during early boot */
19 unsigned long high_physmem;
20
21 extern unsigned long long physmem_size;
22
23 int __init init_maps(unsigned long physmem, unsigned long iomem,
24                      unsigned long highmem)
25 {
26         struct page *p, *map;
27         unsigned long phys_len, phys_pages, highmem_len, highmem_pages;
28         unsigned long iomem_len, iomem_pages, total_len, total_pages;
29         int i;
30
31         phys_pages = physmem >> PAGE_SHIFT;
32         phys_len = phys_pages * sizeof(struct page);
33
34         iomem_pages = iomem >> PAGE_SHIFT;
35         iomem_len = iomem_pages * sizeof(struct page);
36
37         highmem_pages = highmem >> PAGE_SHIFT;
38         highmem_len = highmem_pages * sizeof(struct page);
39
40         total_pages = phys_pages + iomem_pages + highmem_pages;
41         total_len = phys_len + iomem_len + highmem_len;
42
43         map = alloc_bootmem_low_pages(total_len);
44         if (map == NULL)
45                 return -ENOMEM;
46
47         for (i = 0; i < total_pages; i++) {
48                 p = &map[i];
49                 memset(p, 0, sizeof(struct page));
50                 SetPageReserved(p);
51                 INIT_LIST_HEAD(&p->lru);
52         }
53
54         max_mapnr = total_pages;
55         return 0;
56 }
57
58 void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
59                 int r, int w, int x)
60 {
61         __u64 offset;
62         int fd, err;
63
64         fd = phys_mapping(phys, &offset);
65         err = os_map_memory((void *) virt, fd, offset, len, r, w, x);
66         if (err) {
67                 if (err == -ENOMEM)
68                         printk(KERN_ERR "try increasing the host's "
69                                "/proc/sys/vm/max_map_count to <physical "
70                                "memory size>/4096\n");
71                 panic("map_memory(0x%lx, %d, 0x%llx, %ld, %d, %d, %d) failed, "
72                       "err = %d\n", virt, fd, offset, len, r, w, x, err);
73         }
74 }
75
76 extern int __syscall_stub_start;
77
78 void __init setup_physmem(unsigned long start, unsigned long reserve_end,
79                           unsigned long len, unsigned long long highmem)
80 {
81         unsigned long reserve = reserve_end - start;
82         int pfn = PFN_UP(__pa(reserve_end));
83         int delta = (len - reserve) >> PAGE_SHIFT;
84         int err, offset, bootmap_size;
85
86         physmem_fd = create_mem_file(len + highmem);
87
88         offset = uml_reserved - uml_physmem;
89         err = os_map_memory((void *) uml_reserved, physmem_fd, offset,
90                             len - offset, 1, 1, 1);
91         if (err < 0) {
92                 printf("setup_physmem - mapping %ld bytes of memory at 0x%p "
93                        "failed - errno = %d\n", len - offset,
94                        (void *) uml_reserved, err);
95                 exit(1);
96         }
97
98         /*
99          * Special kludge - This page will be mapped in to userspace processes
100          * from physmem_fd, so it needs to be written out there.
101          */
102         os_seek_file(physmem_fd, __pa(&__syscall_stub_start));
103         os_write_file(physmem_fd, &__syscall_stub_start, PAGE_SIZE);
104
105         bootmap_size = init_bootmem(pfn, pfn + delta);
106         free_bootmem(__pa(reserve_end) + bootmap_size,
107                      len - bootmap_size - reserve);
108 }
109
110 int phys_mapping(unsigned long phys, unsigned long long *offset_out)
111 {
112         int fd = -1;
113
114         if (phys < physmem_size) {
115                 fd = physmem_fd;
116                 *offset_out = phys;
117         }
118         else if (phys < __pa(end_iomem)) {
119                 struct iomem_region *region = iomem_regions;
120
121                 while (region != NULL) {
122                         if ((phys >= region->phys) &&
123                             (phys < region->phys + region->size)) {
124                                 fd = region->fd;
125                                 *offset_out = phys - region->phys;
126                                 break;
127                         }
128                         region = region->next;
129                 }
130         }
131         else if (phys < __pa(end_iomem) + highmem) {
132                 fd = physmem_fd;
133                 *offset_out = phys - iomem_size;
134         }
135
136         return fd;
137 }
138
139 static int __init uml_mem_setup(char *line, int *add)
140 {
141         char *retptr;
142         physmem_size = memparse(line,&retptr);
143         return 0;
144 }
145 __uml_setup("mem=", uml_mem_setup,
146 "mem=<Amount of desired ram>\n"
147 "    This controls how much \"physical\" memory the kernel allocates\n"
148 "    for the system. The size is specified as a number followed by\n"
149 "    one of 'k', 'K', 'm', 'M', which have the obvious meanings.\n"
150 "    This is not related to the amount of memory in the host.  It can\n"
151 "    be more, and the excess, if it's ever used, will just be swapped out.\n"
152 "       Example: mem=64M\n\n"
153 );
154
155 extern int __init parse_iomem(char *str, int *add);
156
157 __uml_setup("iomem=", parse_iomem,
158 "iomem=<name>,<file>\n"
159 "    Configure <file> as an IO memory region named <name>.\n\n"
160 );
161
162 /*
163  * This list is constructed in parse_iomem and addresses filled in in
164  * setup_iomem, both of which run during early boot.  Afterwards, it's
165  * unchanged.
166  */
167 struct iomem_region *iomem_regions;
168
169 /* Initialized in parse_iomem and unchanged thereafter */
170 int iomem_size;
171
172 unsigned long find_iomem(char *driver, unsigned long *len_out)
173 {
174         struct iomem_region *region = iomem_regions;
175
176         while (region != NULL) {
177                 if (!strcmp(region->driver, driver)) {
178                         *len_out = region->size;
179                         return region->virt;
180                 }
181
182                 region = region->next;
183         }
184
185         return 0;
186 }
187
188 static int setup_iomem(void)
189 {
190         struct iomem_region *region = iomem_regions;
191         unsigned long iomem_start = high_physmem + PAGE_SIZE;
192         int err;
193
194         while (region != NULL) {
195                 err = os_map_memory((void *) iomem_start, region->fd, 0,
196                                     region->size, 1, 1, 0);
197                 if (err)
198                         printk(KERN_ERR "Mapping iomem region for driver '%s' "
199                                "failed, errno = %d\n", region->driver, -err);
200                 else {
201                         region->virt = iomem_start;
202                         region->phys = __pa(region->virt);
203                 }
204
205                 iomem_start += region->size + PAGE_SIZE;
206                 region = region->next;
207         }
208
209         return 0;
210 }
211
212 __initcall(setup_iomem);