Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : /*
3 : * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 : */
5 :
6 : #include <linux/module.h>
7 : #include <linux/memblock.h>
8 : #include <linux/mm.h>
9 : #include <linux/pfn.h>
10 : #include <asm/page.h>
11 : #include <asm/sections.h>
12 : #include <as-layout.h>
13 : #include <init.h>
14 : #include <kern.h>
15 : #include <mem_user.h>
16 : #include <os.h>
17 :
18 : static int physmem_fd = -1;
19 :
20 : /* Changed during early boot */
21 : unsigned long high_physmem;
22 : EXPORT_SYMBOL(high_physmem);
23 :
24 : extern unsigned long long physmem_size;
25 :
26 1 : void __init mem_total_pages(unsigned long physmem, unsigned long iomem,
27 : unsigned long highmem)
28 : {
29 : unsigned long phys_pages, highmem_pages;
30 : unsigned long iomem_pages, total_pages;
31 :
32 1 : phys_pages = physmem >> PAGE_SHIFT;
33 1 : iomem_pages = iomem >> PAGE_SHIFT;
34 1 : highmem_pages = highmem >> PAGE_SHIFT;
35 :
36 1 : total_pages = phys_pages + iomem_pages + highmem_pages;
37 :
38 1 : max_mapnr = total_pages;
39 1 : }
40 :
41 65 : void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
42 : int r, int w, int x)
43 : {
44 : __u64 offset;
45 : int fd, err;
46 :
47 65 : fd = phys_mapping(phys, &offset);
48 65 : err = os_map_memory((void *) virt, fd, offset, len, r, w, x);
49 65 : if (err) {
50 0 : if (err == -ENOMEM)
51 0 : printk(KERN_ERR "try increasing the host's "
52 : "/proc/sys/vm/max_map_count to <physical "
53 : "memory size>/4096\n");
54 0 : panic("map_memory(0x%lx, %d, 0x%llx, %ld, %d, %d, %d) failed, "
55 : "err = %d\n", virt, fd, offset, len, r, w, x, err);
56 : }
57 65 : }
58 :
59 : /**
60 : * setup_physmem() - Setup physical memory for UML
61 : * @start: Start address of the physical kernel memory,
62 : * i.e start address of the executable image.
63 : * @reserve_end: end address of the physical kernel memory.
64 : * @len: Length of total physical memory that should be mapped/made
65 : * available, in bytes.
66 : * @highmem: Number of highmem bytes that should be mapped/made available.
67 : *
68 : * Creates an unlinked temporary file of size (len + highmem) and memory maps
69 : * it on the last executable image address (uml_reserved).
70 : *
71 : * The offset is needed as the length of the total physical memory
72 : * (len + highmem) includes the size of the memory used be the executable image,
73 : * but the mapped-to address is the last address of the executable image
74 : * (uml_reserved == end address of executable image).
75 : *
76 : * The memory mapped memory of the temporary file is used as backing memory
77 : * of all user space processes/kernel tasks.
78 : */
79 1 : void __init setup_physmem(unsigned long start, unsigned long reserve_end,
80 : unsigned long len, unsigned long long highmem)
81 : {
82 1 : unsigned long reserve = reserve_end - start;
83 1 : long map_size = len - reserve;
84 : int err;
85 :
86 1 : if(map_size <= 0) {
87 0 : os_warn("Too few physical memory! Needed=%lu, given=%lu\n",
88 : reserve, len);
89 0 : exit(1);
90 : }
91 :
92 1 : physmem_fd = create_mem_file(len + highmem);
93 :
94 1 : err = os_map_memory((void *) reserve_end, physmem_fd, reserve,
95 : map_size, 1, 1, 1);
96 1 : if (err < 0) {
97 0 : os_warn("setup_physmem - mapping %ld bytes of memory at 0x%p "
98 : "failed - errno = %d\n", map_size,
99 : (void *) reserve_end, err);
100 0 : exit(1);
101 : }
102 :
103 : /*
104 : * Special kludge - This page will be mapped in to userspace processes
105 : * from physmem_fd, so it needs to be written out there.
106 : */
107 1 : os_seek_file(physmem_fd, __pa(__syscall_stub_start));
108 1 : os_write_file(physmem_fd, __syscall_stub_start, PAGE_SIZE);
109 1 : os_fsync_file(physmem_fd);
110 :
111 2 : memblock_add(__pa(start), len + highmem);
112 2 : memblock_reserve(__pa(start), reserve);
113 :
114 2 : min_low_pfn = PFN_UP(__pa(reserve_end));
115 1 : max_low_pfn = min_low_pfn + (map_size >> PAGE_SHIFT);
116 1 : }
117 :
118 65 : int phys_mapping(unsigned long phys, unsigned long long *offset_out)
119 : {
120 65 : int fd = -1;
121 :
122 65 : if (phys < physmem_size) {
123 65 : fd = physmem_fd;
124 65 : *offset_out = phys;
125 : }
126 0 : else if (phys < __pa(end_iomem)) {
127 0 : struct iomem_region *region = iomem_regions;
128 :
129 0 : while (region != NULL) {
130 0 : if ((phys >= region->phys) &&
131 0 : (phys < region->phys + region->size)) {
132 0 : fd = region->fd;
133 0 : *offset_out = phys - region->phys;
134 0 : break;
135 : }
136 0 : region = region->next;
137 : }
138 : }
139 0 : else if (phys < __pa(end_iomem) + highmem) {
140 0 : fd = physmem_fd;
141 0 : *offset_out = phys - iomem_size;
142 : }
143 :
144 65 : return fd;
145 : }
146 : EXPORT_SYMBOL(phys_mapping);
147 :
148 5 : static int __init uml_mem_setup(char *line, int *add)
149 : {
150 : char *retptr;
151 5 : physmem_size = memparse(line,&retptr);
152 5 : return 0;
153 : }
154 : __uml_setup("mem=", uml_mem_setup,
155 : "mem=<Amount of desired ram>\n"
156 : " This controls how much \"physical\" memory the kernel allocates\n"
157 : " for the system. The size is specified as a number followed by\n"
158 : " one of 'k', 'K', 'm', 'M', which have the obvious meanings.\n"
159 : " This is not related to the amount of memory in the host. It can\n"
160 : " be more, and the excess, if it's ever used, will just be swapped out.\n"
161 : " Example: mem=64M\n\n"
162 : );
163 :
164 : extern int __init parse_iomem(char *str, int *add);
165 :
166 : __uml_setup("iomem=", parse_iomem,
167 : "iomem=<name>,<file>\n"
168 : " Configure <file> as an IO memory region named <name>.\n\n"
169 : );
170 :
171 : /*
172 : * This list is constructed in parse_iomem and addresses filled in
173 : * setup_iomem, both of which run during early boot. Afterwards, it's
174 : * unchanged.
175 : */
176 : struct iomem_region *iomem_regions;
177 :
178 : /* Initialized in parse_iomem and unchanged thereafter */
179 : int iomem_size;
180 :
181 0 : unsigned long find_iomem(char *driver, unsigned long *len_out)
182 : {
183 0 : struct iomem_region *region = iomem_regions;
184 :
185 0 : while (region != NULL) {
186 0 : if (!strcmp(region->driver, driver)) {
187 0 : *len_out = region->size;
188 0 : return region->virt;
189 : }
190 :
191 0 : region = region->next;
192 : }
193 :
194 : return 0;
195 : }
196 : EXPORT_SYMBOL(find_iomem);
197 :
198 1 : static int setup_iomem(void)
199 : {
200 1 : struct iomem_region *region = iomem_regions;
201 1 : unsigned long iomem_start = high_physmem + PAGE_SIZE;
202 : int err;
203 :
204 2 : while (region != NULL) {
205 0 : err = os_map_memory((void *) iomem_start, region->fd, 0,
206 0 : region->size, 1, 1, 0);
207 0 : if (err)
208 0 : printk(KERN_ERR "Mapping iomem region for driver '%s' "
209 : "failed, errno = %d\n", region->driver, -err);
210 : else {
211 0 : region->virt = iomem_start;
212 0 : region->phys = __pa(region->virt);
213 : }
214 :
215 0 : iomem_start += region->size + PAGE_SIZE;
216 0 : region = region->next;
217 : }
218 :
219 1 : return 0;
220 : }
221 :
222 : __initcall(setup_iomem);
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