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 physmem_size; 250 251 void *to_virt(unsigned long phys) 252 { 253 return((void *) uml_physmem + phys); 254 } 255 256 unsigned long to_phys(void *virt) 257 { 258 return(((unsigned long) virt) - uml_physmem); 259 } 260 261 int init_maps(unsigned long physmem, unsigned long iomem, unsigned long highmem) 262 { 263 struct page *p, *map; 264 unsigned long phys_len, phys_pages, highmem_len, highmem_pages; 265 unsigned long iomem_len, iomem_pages, total_len, total_pages; 266 int i; 267 268 phys_pages = physmem >> PAGE_SHIFT; 269 phys_len = phys_pages * sizeof(struct page); 270 271 iomem_pages = iomem >> PAGE_SHIFT; 272 iomem_len = iomem_pages * sizeof(struct page); 273 274 highmem_pages = highmem >> PAGE_SHIFT; 275 highmem_len = highmem_pages * sizeof(struct page); 276 277 total_pages = phys_pages + iomem_pages + highmem_pages; 278 total_len = phys_len + iomem_pages + highmem_len; 279 280 if(kmalloc_ok){ 281 map = kmalloc(total_len, GFP_KERNEL); 282 if(map == NULL) 283 map = vmalloc(total_len); 284 } 285 else map = alloc_bootmem_low_pages(total_len); 286 287 if(map == NULL) 288 return(-ENOMEM); 289 290 for(i = 0; i < total_pages; i++){ 291 p = &map[i]; 292 set_page_count(p, 0); 293 SetPageReserved(p); 294 INIT_LIST_HEAD(&p->lru); 295 } 296 297 max_mapnr = total_pages; 298 return(0); 299 } 300 301 struct page *phys_to_page(const unsigned long phys) 302 { 303 return(&mem_map[phys >> PAGE_SHIFT]); 304 } 305 306 struct page *__virt_to_page(const unsigned long virt) 307 { 308 return(&mem_map[__pa(virt) >> PAGE_SHIFT]); 309 } 310 311 phys_t page_to_phys(struct page *page) 312 { 313 return((page - mem_map) << PAGE_SHIFT); 314 } 315 316 pte_t mk_pte(struct page *page, pgprot_t pgprot) 317 { 318 pte_t pte; 319 320 pte_set_val(pte, page_to_phys(page), pgprot); 321 if(pte_present(pte)) 322 pte_mknewprot(pte_mknewpage(pte)); 323 return(pte); 324 } 325 326 /* Changed during early boot */ 327 static unsigned long kmem_top = 0; 328 329 unsigned long get_kmem_end(void) 330 { 331 if(kmem_top == 0) 332 kmem_top = CHOOSE_MODE(kmem_end_tt, kmem_end_skas); 333 return(kmem_top); 334 } 335 336 void map_memory(unsigned long virt, unsigned long phys, unsigned long len, 337 int r, int w, int x) 338 { 339 __u64 offset; 340 int fd, err; 341 342 fd = phys_mapping(phys, &offset); 343 err = os_map_memory((void *) virt, fd, offset, len, r, w, x); 344 if(err) { 345 if(err == -ENOMEM) 346 printk("try increasing the host's " 347 "/proc/sys/vm/max_map_count to <physical " 348 "memory size>/4096\n"); 349 panic("map_memory(0x%lx, %d, 0x%llx, %ld, %d, %d, %d) failed, " 350 "err = %d\n", virt, fd, offset, len, r, w, x, err); 351 } 352 } 353 354 #define PFN_UP(x) (((x) + PAGE_SIZE-1) >> PAGE_SHIFT) 355 356 extern int __syscall_stub_start, __binary_start; 357 358 void setup_physmem(unsigned long start, unsigned long reserve_end, 359 unsigned long len, unsigned long highmem) 360 { 361 unsigned long reserve = reserve_end - start; 362 int pfn = PFN_UP(__pa(reserve_end)); 363 int delta = (len - reserve) >> PAGE_SHIFT; 364 int err, offset, bootmap_size; 365 366 physmem_fd = create_mem_file(len + highmem); 367 368 offset = uml_reserved - uml_physmem; 369 err = os_map_memory((void *) uml_reserved, physmem_fd, offset, 370 len - offset, 1, 1, 0); 371 if(err < 0){ 372 os_print_error(err, "Mapping memory"); 373 exit(1); 374 } 375 376 /* Special kludge - This page will be mapped in to userspace processes 377 * from physmem_fd, so it needs to be written out there. 378 */ 379 os_seek_file(physmem_fd, __pa(&__syscall_stub_start)); 380 os_write_file(physmem_fd, &__syscall_stub_start, PAGE_SIZE); 381 382 bootmap_size = init_bootmem(pfn, pfn + delta); 383 free_bootmem(__pa(reserve_end) + bootmap_size, 384 len - bootmap_size - reserve); 385 } 386 387 int phys_mapping(unsigned long phys, __u64 *offset_out) 388 { 389 struct phys_desc *desc = find_phys_mapping(__va(phys & PAGE_MASK)); 390 int fd = -1; 391 392 if(desc != NULL){ 393 fd = desc->fd; 394 *offset_out = desc->offset; 395 } 396 else if(phys < physmem_size){ 397 fd = physmem_fd; 398 *offset_out = phys; 399 } 400 else if(phys < __pa(end_iomem)){ 401 struct iomem_region *region = iomem_regions; 402 403 while(region != NULL){ 404 if((phys >= region->phys) && 405 (phys < region->phys + region->size)){ 406 fd = region->fd; 407 *offset_out = phys - region->phys; 408 break; 409 } 410 region = region->next; 411 } 412 } 413 else if(phys < __pa(end_iomem) + highmem){ 414 fd = physmem_fd; 415 *offset_out = phys - iomem_size; 416 } 417 418 return(fd); 419 } 420 421 static int __init uml_mem_setup(char *line, int *add) 422 { 423 char *retptr; 424 physmem_size = memparse(line,&retptr); 425 return 0; 426 } 427 __uml_setup("mem=", uml_mem_setup, 428 "mem=<Amount of desired ram>\n" 429 " This controls how much \"physical\" memory the kernel allocates\n" 430 " for the system. The size is specified as a number followed by\n" 431 " one of 'k', 'K', 'm', 'M', which have the obvious meanings.\n" 432 " This is not related to the amount of memory in the host. It can\n" 433 " be more, and the excess, if it's ever used, will just be swapped out.\n" 434 " Example: mem=64M\n\n" 435 ); 436 437 unsigned long find_iomem(char *driver, unsigned long *len_out) 438 { 439 struct iomem_region *region = iomem_regions; 440 441 while(region != NULL){ 442 if(!strcmp(region->driver, driver)){ 443 *len_out = region->size; 444 return(region->virt); 445 } 446 } 447 448 return(0); 449 } 450 451 int setup_iomem(void) 452 { 453 struct iomem_region *region = iomem_regions; 454 unsigned long iomem_start = high_physmem + PAGE_SIZE; 455 int err; 456 457 while(region != NULL){ 458 err = os_map_memory((void *) iomem_start, region->fd, 0, 459 region->size, 1, 1, 0); 460 if(err) 461 printk("Mapping iomem region for driver '%s' failed, " 462 "errno = %d\n", region->driver, -err); 463 else { 464 region->virt = iomem_start; 465 region->phys = __pa(region->virt); 466 } 467 468 iomem_start += region->size + PAGE_SIZE; 469 region = region->next; 470 } 471 472 return(0); 473 } 474 475 __initcall(setup_iomem); 476 477 /* 478 * Overrides for Emacs so that we follow Linus's tabbing style. 479 * Emacs will notice this stuff at the end of the file and automatically 480 * adjust the settings for this buffer only. This must remain at the end 481 * of the file. 482 * --------------------------------------------------------------------------- 483 * Local variables: 484 * c-file-style: "linux" 485 * End: 486 */ 487