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 /* Changed during early boot */ 59 static unsigned long kmem_top = 0; 60 61 unsigned long get_kmem_end(void) 62 { 63 if (kmem_top == 0) 64 kmem_top = host_task_size - 1024 * 1024; 65 return kmem_top; 66 } 67 68 void map_memory(unsigned long virt, unsigned long phys, unsigned long len, 69 int r, int w, int x) 70 { 71 __u64 offset; 72 int fd, err; 73 74 fd = phys_mapping(phys, &offset); 75 err = os_map_memory((void *) virt, fd, offset, len, r, w, x); 76 if (err) { 77 if (err == -ENOMEM) 78 printk("try increasing the host's " 79 "/proc/sys/vm/max_map_count to <physical " 80 "memory size>/4096\n"); 81 panic("map_memory(0x%lx, %d, 0x%llx, %ld, %d, %d, %d) failed, " 82 "err = %d\n", virt, fd, offset, len, r, w, x, err); 83 } 84 } 85 86 extern int __syscall_stub_start; 87 88 void __init setup_physmem(unsigned long start, unsigned long reserve_end, 89 unsigned long len, unsigned long long highmem) 90 { 91 unsigned long reserve = reserve_end - start; 92 int pfn = PFN_UP(__pa(reserve_end)); 93 int delta = (len - reserve) >> PAGE_SHIFT; 94 int err, offset, bootmap_size; 95 96 physmem_fd = create_mem_file(len + highmem); 97 98 offset = uml_reserved - uml_physmem; 99 err = os_map_memory((void *) uml_reserved, physmem_fd, offset, 100 len - offset, 1, 1, 1); 101 if (err < 0) { 102 os_print_error(err, "Mapping memory"); 103 exit(1); 104 } 105 106 /* Special kludge - This page will be mapped in to userspace processes 107 * from physmem_fd, so it needs to be written out there. 108 */ 109 os_seek_file(physmem_fd, __pa(&__syscall_stub_start)); 110 os_write_file(physmem_fd, &__syscall_stub_start, PAGE_SIZE); 111 112 bootmap_size = init_bootmem(pfn, pfn + delta); 113 free_bootmem(__pa(reserve_end) + bootmap_size, 114 len - bootmap_size - reserve); 115 } 116 117 int phys_mapping(unsigned long phys, __u64 *offset_out) 118 { 119 int fd = -1; 120 121 if (phys < physmem_size) { 122 fd = physmem_fd; 123 *offset_out = phys; 124 } 125 else if (phys < __pa(end_iomem)) { 126 struct iomem_region *region = iomem_regions; 127 128 while (region != NULL) { 129 if ((phys >= region->phys) && 130 (phys < region->phys + region->size)) { 131 fd = region->fd; 132 *offset_out = phys - region->phys; 133 break; 134 } 135 region = region->next; 136 } 137 } 138 else if (phys < __pa(end_iomem) + highmem) { 139 fd = physmem_fd; 140 *offset_out = phys - iomem_size; 141 } 142 143 return fd; 144 } 145 146 static int __init uml_mem_setup(char *line, int *add) 147 { 148 char *retptr; 149 physmem_size = memparse(line,&retptr); 150 return 0; 151 } 152 __uml_setup("mem=", uml_mem_setup, 153 "mem=<Amount of desired ram>\n" 154 " This controls how much \"physical\" memory the kernel allocates\n" 155 " for the system. The size is specified as a number followed by\n" 156 " one of 'k', 'K', 'm', 'M', which have the obvious meanings.\n" 157 " This is not related to the amount of memory in the host. It can\n" 158 " be more, and the excess, if it's ever used, will just be swapped out.\n" 159 " Example: mem=64M\n\n" 160 ); 161 162 extern int __init parse_iomem(char *str, int *add); 163 164 __uml_setup("iomem=", parse_iomem, 165 "iomem=<name>,<file>\n" 166 " Configure <file> as an IO memory region named <name>.\n\n" 167 ); 168 169 /* 170 * This list is constructed in parse_iomem and addresses filled in in 171 * setup_iomem, both of which run during early boot. Afterwards, it's 172 * unchanged. 173 */ 174 struct iomem_region *iomem_regions = NULL; 175 176 /* Initialized in parse_iomem */ 177 int iomem_size = 0; 178 179 unsigned long find_iomem(char *driver, unsigned long *len_out) 180 { 181 struct iomem_region *region = iomem_regions; 182 183 while (region != NULL) { 184 if (!strcmp(region->driver, driver)) { 185 *len_out = region->size; 186 return region->virt; 187 } 188 189 region = region->next; 190 } 191 192 return 0; 193 } 194 195 int setup_iomem(void) 196 { 197 struct iomem_region *region = iomem_regions; 198 unsigned long iomem_start = high_physmem + PAGE_SIZE; 199 int err; 200 201 while (region != NULL) { 202 err = os_map_memory((void *) iomem_start, region->fd, 0, 203 region->size, 1, 1, 0); 204 if (err) 205 printk("Mapping iomem region for driver '%s' failed, " 206 "errno = %d\n", region->driver, -err); 207 else { 208 region->virt = iomem_start; 209 region->phys = __pa(region->virt); 210 } 211 212 iomem_start += region->size + PAGE_SIZE; 213 region = region->next; 214 } 215 216 return 0; 217 } 218 219 __initcall(setup_iomem); 220