1 /* 2 * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com) 3 * Licensed under the GPL 4 */ 5 6 #include "linux/mm.h" 7 #include "linux/rbtree.h" 8 #include "linux/slab.h" 9 #include "linux/vmalloc.h" 10 #include "linux/bootmem.h" 11 #include "linux/module.h" 12 #include "asm/types.h" 13 #include "asm/pgtable.h" 14 #include "kern_util.h" 15 #include "user_util.h" 16 #include "mode_kern.h" 17 #include "mem.h" 18 #include "mem_user.h" 19 #include "os.h" 20 #include "kern.h" 21 #include "init.h" 22 23 struct phys_desc { 24 struct rb_node rb; 25 int fd; 26 __u64 offset; 27 void *virt; 28 unsigned long phys; 29 struct list_head list; 30 }; 31 32 static struct rb_root phys_mappings = RB_ROOT; 33 34 static struct rb_node **find_rb(void *virt) 35 { 36 struct rb_node **n = &phys_mappings.rb_node; 37 struct phys_desc *d; 38 39 while(*n != NULL){ 40 d = rb_entry(*n, struct phys_desc, rb); 41 if(d->virt == virt) 42 return(n); 43 44 if(d->virt > virt) 45 n = &(*n)->rb_left; 46 else 47 n = &(*n)->rb_right; 48 } 49 50 return(n); 51 } 52 53 static struct phys_desc *find_phys_mapping(void *virt) 54 { 55 struct rb_node **n = find_rb(virt); 56 57 if(*n == NULL) 58 return(NULL); 59 60 return(rb_entry(*n, struct phys_desc, rb)); 61 } 62 63 static void insert_phys_mapping(struct phys_desc *desc) 64 { 65 struct rb_node **n = find_rb(desc->virt); 66 67 if(*n != NULL) 68 panic("Physical remapping for %p already present", 69 desc->virt); 70 71 rb_link_node(&desc->rb, (*n)->rb_parent, n); 72 rb_insert_color(&desc->rb, &phys_mappings); 73 } 74 75 LIST_HEAD(descriptor_mappings); 76 77 struct desc_mapping { 78 int fd; 79 struct list_head list; 80 struct list_head pages; 81 }; 82 83 static struct desc_mapping *find_mapping(int fd) 84 { 85 struct desc_mapping *desc; 86 struct list_head *ele; 87 88 list_for_each(ele, &descriptor_mappings){ 89 desc = list_entry(ele, struct desc_mapping, list); 90 if(desc->fd == fd) 91 return(desc); 92 } 93 94 return(NULL); 95 } 96 97 static struct desc_mapping *descriptor_mapping(int fd) 98 { 99 struct desc_mapping *desc; 100 101 desc = find_mapping(fd); 102 if(desc != NULL) 103 return(desc); 104 105 desc = kmalloc(sizeof(*desc), GFP_ATOMIC); 106 if(desc == NULL) 107 return(NULL); 108 109 *desc = ((struct desc_mapping) 110 { .fd = fd, 111 .list = LIST_HEAD_INIT(desc->list), 112 .pages = LIST_HEAD_INIT(desc->pages) }); 113 list_add(&desc->list, &descriptor_mappings); 114 115 return(desc); 116 } 117 118 int physmem_subst_mapping(void *virt, int fd, __u64 offset, int w) 119 { 120 struct desc_mapping *fd_maps; 121 struct phys_desc *desc; 122 unsigned long phys; 123 int err; 124 125 fd_maps = descriptor_mapping(fd); 126 if(fd_maps == NULL) 127 return(-ENOMEM); 128 129 phys = __pa(virt); 130 desc = find_phys_mapping(virt); 131 if(desc != NULL) 132 panic("Address 0x%p is already substituted\n", virt); 133 134 err = -ENOMEM; 135 desc = kmalloc(sizeof(*desc), GFP_ATOMIC); 136 if(desc == NULL) 137 goto out; 138 139 *desc = ((struct phys_desc) 140 { .fd = fd, 141 .offset = offset, 142 .virt = virt, 143 .phys = __pa(virt), 144 .list = LIST_HEAD_INIT(desc->list) }); 145 insert_phys_mapping(desc); 146 147 list_add(&desc->list, &fd_maps->pages); 148 149 virt = (void *) ((unsigned long) virt & PAGE_MASK); 150 err = os_map_memory(virt, fd, offset, PAGE_SIZE, 1, w, 0); 151 if(!err) 152 goto out; 153 154 rb_erase(&desc->rb, &phys_mappings); 155 kfree(desc); 156 out: 157 return(err); 158 } 159 160 static int physmem_fd = -1; 161 162 static void remove_mapping(struct phys_desc *desc) 163 { 164 void *virt = desc->virt; 165 int err; 166 167 rb_erase(&desc->rb, &phys_mappings); 168 list_del(&desc->list); 169 kfree(desc); 170 171 err = os_map_memory(virt, physmem_fd, __pa(virt), PAGE_SIZE, 1, 1, 0); 172 if(err) 173 panic("Failed to unmap block device page from physical memory, " 174 "errno = %d", -err); 175 } 176 177 int physmem_remove_mapping(void *virt) 178 { 179 struct phys_desc *desc; 180 181 virt = (void *) ((unsigned long) virt & PAGE_MASK); 182 desc = find_phys_mapping(virt); 183 if(desc == NULL) 184 return(0); 185 186 remove_mapping(desc); 187 return(1); 188 } 189 190 void physmem_forget_descriptor(int fd) 191 { 192 struct desc_mapping *desc; 193 struct phys_desc *page; 194 struct list_head *ele, *next; 195 __u64 offset; 196 void *addr; 197 int err; 198 199 desc = find_mapping(fd); 200 if(desc == NULL) 201 return; 202 203 list_for_each_safe(ele, next, &desc->pages){ 204 page = list_entry(ele, struct phys_desc, list); 205 offset = page->offset; 206 addr = page->virt; 207 remove_mapping(page); 208 err = os_seek_file(fd, offset); 209 if(err) 210 panic("physmem_forget_descriptor - failed to seek " 211 "to %lld in fd %d, error = %d\n", 212 offset, fd, -err); 213 err = os_read_file(fd, addr, PAGE_SIZE); 214 if(err < 0) 215 panic("physmem_forget_descriptor - failed to read " 216 "from fd %d to 0x%p, error = %d\n", 217 fd, addr, -err); 218 } 219 220 list_del(&desc->list); 221 kfree(desc); 222 } 223 224 EXPORT_SYMBOL(physmem_forget_descriptor); 225 EXPORT_SYMBOL(physmem_remove_mapping); 226 EXPORT_SYMBOL(physmem_subst_mapping); 227 228 void arch_free_page(struct page *page, int order) 229 { 230 void *virt; 231 int i; 232 233 for(i = 0; i < (1 << order); i++){ 234 virt = __va(page_to_phys(page + i)); 235 physmem_remove_mapping(virt); 236 } 237 } 238 239 int is_remapped(void *virt) 240 { 241 struct phys_desc *desc = find_phys_mapping(virt); 242 243 return(desc != NULL); 244 } 245 246 /* Changed during early boot */ 247 unsigned long high_physmem; 248 249 extern unsigned long long physmem_size; 250 251 int init_maps(unsigned long physmem, unsigned long iomem, unsigned long highmem) 252 { 253 struct page *p, *map; 254 unsigned long phys_len, phys_pages, highmem_len, highmem_pages; 255 unsigned long iomem_len, iomem_pages, total_len, total_pages; 256 int i; 257 258 phys_pages = physmem >> PAGE_SHIFT; 259 phys_len = phys_pages * sizeof(struct page); 260 261 iomem_pages = iomem >> PAGE_SHIFT; 262 iomem_len = iomem_pages * sizeof(struct page); 263 264 highmem_pages = highmem >> PAGE_SHIFT; 265 highmem_len = highmem_pages * sizeof(struct page); 266 267 total_pages = phys_pages + iomem_pages + highmem_pages; 268 total_len = phys_len + iomem_pages + highmem_len; 269 270 if(kmalloc_ok){ 271 map = kmalloc(total_len, GFP_KERNEL); 272 if(map == NULL) 273 map = vmalloc(total_len); 274 } 275 else map = alloc_bootmem_low_pages(total_len); 276 277 if(map == NULL) 278 return(-ENOMEM); 279 280 for(i = 0; i < total_pages; i++){ 281 p = &map[i]; 282 set_page_count(p, 0); 283 SetPageReserved(p); 284 INIT_LIST_HEAD(&p->lru); 285 } 286 287 max_mapnr = total_pages; 288 return(0); 289 } 290 291 /* Changed during early boot */ 292 static unsigned long kmem_top = 0; 293 294 unsigned long get_kmem_end(void) 295 { 296 if(kmem_top == 0) 297 kmem_top = CHOOSE_MODE(kmem_end_tt, kmem_end_skas); 298 return(kmem_top); 299 } 300 301 void map_memory(unsigned long virt, unsigned long phys, unsigned long len, 302 int r, int w, int x) 303 { 304 __u64 offset; 305 int fd, err; 306 307 fd = phys_mapping(phys, &offset); 308 err = os_map_memory((void *) virt, fd, offset, len, r, w, x); 309 if(err) { 310 if(err == -ENOMEM) 311 printk("try increasing the host's " 312 "/proc/sys/vm/max_map_count to <physical " 313 "memory size>/4096\n"); 314 panic("map_memory(0x%lx, %d, 0x%llx, %ld, %d, %d, %d) failed, " 315 "err = %d\n", virt, fd, offset, len, r, w, x, err); 316 } 317 } 318 319 #define PFN_UP(x) (((x) + PAGE_SIZE-1) >> PAGE_SHIFT) 320 321 extern int __syscall_stub_start, __binary_start; 322 323 void setup_physmem(unsigned long start, unsigned long reserve_end, 324 unsigned long len, unsigned long long highmem) 325 { 326 unsigned long reserve = reserve_end - start; 327 int pfn = PFN_UP(__pa(reserve_end)); 328 int delta = (len - reserve) >> PAGE_SHIFT; 329 int err, offset, bootmap_size; 330 331 physmem_fd = create_mem_file(len + highmem); 332 333 offset = uml_reserved - uml_physmem; 334 err = os_map_memory((void *) uml_reserved, physmem_fd, offset, 335 len - offset, 1, 1, 0); 336 if(err < 0){ 337 os_print_error(err, "Mapping memory"); 338 exit(1); 339 } 340 341 /* Special kludge - This page will be mapped in to userspace processes 342 * from physmem_fd, so it needs to be written out there. 343 */ 344 os_seek_file(physmem_fd, __pa(&__syscall_stub_start)); 345 os_write_file(physmem_fd, &__syscall_stub_start, PAGE_SIZE); 346 347 bootmap_size = init_bootmem(pfn, pfn + delta); 348 free_bootmem(__pa(reserve_end) + bootmap_size, 349 len - bootmap_size - reserve); 350 } 351 352 int phys_mapping(unsigned long phys, __u64 *offset_out) 353 { 354 struct phys_desc *desc = find_phys_mapping(__va(phys & PAGE_MASK)); 355 int fd = -1; 356 357 if(desc != NULL){ 358 fd = desc->fd; 359 *offset_out = desc->offset; 360 } 361 else if(phys < physmem_size){ 362 fd = physmem_fd; 363 *offset_out = phys; 364 } 365 else if(phys < __pa(end_iomem)){ 366 struct iomem_region *region = iomem_regions; 367 368 while(region != NULL){ 369 if((phys >= region->phys) && 370 (phys < region->phys + region->size)){ 371 fd = region->fd; 372 *offset_out = phys - region->phys; 373 break; 374 } 375 region = region->next; 376 } 377 } 378 else if(phys < __pa(end_iomem) + highmem){ 379 fd = physmem_fd; 380 *offset_out = phys - iomem_size; 381 } 382 383 return(fd); 384 } 385 386 static int __init uml_mem_setup(char *line, int *add) 387 { 388 char *retptr; 389 physmem_size = memparse(line,&retptr); 390 return 0; 391 } 392 __uml_setup("mem=", uml_mem_setup, 393 "mem=<Amount of desired ram>\n" 394 " This controls how much \"physical\" memory the kernel allocates\n" 395 " for the system. The size is specified as a number followed by\n" 396 " one of 'k', 'K', 'm', 'M', which have the obvious meanings.\n" 397 " This is not related to the amount of memory in the host. It can\n" 398 " be more, and the excess, if it's ever used, will just be swapped out.\n" 399 " Example: mem=64M\n\n" 400 ); 401 402 unsigned long find_iomem(char *driver, unsigned long *len_out) 403 { 404 struct iomem_region *region = iomem_regions; 405 406 while(region != NULL){ 407 if(!strcmp(region->driver, driver)){ 408 *len_out = region->size; 409 return(region->virt); 410 } 411 } 412 413 return(0); 414 } 415 416 int setup_iomem(void) 417 { 418 struct iomem_region *region = iomem_regions; 419 unsigned long iomem_start = high_physmem + PAGE_SIZE; 420 int err; 421 422 while(region != NULL){ 423 err = os_map_memory((void *) iomem_start, region->fd, 0, 424 region->size, 1, 1, 0); 425 if(err) 426 printk("Mapping iomem region for driver '%s' failed, " 427 "errno = %d\n", region->driver, -err); 428 else { 429 region->virt = iomem_start; 430 region->phys = __pa(region->virt); 431 } 432 433 iomem_start += region->size + PAGE_SIZE; 434 region = region->next; 435 } 436 437 return(0); 438 } 439 440 __initcall(setup_iomem); 441 442 /* 443 * Overrides for Emacs so that we follow Linus's tabbing style. 444 * Emacs will notice this stuff at the end of the file and automatically 445 * adjust the settings for this buffer only. This must remain at the end 446 * of the file. 447 * --------------------------------------------------------------------------- 448 * Local variables: 449 * c-file-style: "linux" 450 * End: 451 */ 452