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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 | /* * linux/drivers/char/mem.c * * Copyright (C) 1991, 1992 Linus Torvalds */ #include <linux/config.h> #include <linux/types.h> #include <linux/errno.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/major.h> #include <linux/tty.h> #include <linux/miscdevice.h> #include <linux/tpqic02.h> #include <linux/ftape.h> #include <linux/malloc.h> #include <linux/vmalloc.h> #include <linux/mman.h> #include <linux/mm.h> #include <linux/random.h> #include <linux/init.h> #include <linux/joystick.h> #include <asm/uaccess.h> #include <asm/io.h> #include <asm/pgtable.h> #ifdef CONFIG_SOUND void soundcard_init(void); #endif #ifdef CONFIG_ISDN void isdn_init(void); #endif #ifdef CONFIG_PCWATCHDOG void pcwatchdog_init(void); #endif static ssize_t do_write_mem(struct file * file, void *p, unsigned long realp, const char * buf, size_t count, loff_t *ppos) { ssize_t written; written = 0; #if defined(__sparc__) || defined(__mc68000__) /* we don't have page 0 mapped on sparc and m68k.. */ if (realp < PAGE_SIZE) { unsigned long sz = PAGE_SIZE-realp; if (sz > count) sz = count; /* Hmm. Do something? */ buf+=sz; p+=sz; count-=sz; written+=sz; } #endif if (copy_from_user(p, buf, count) < 0) return -EFAULT; written += count; *ppos += written; return written; } /* * This funcion reads the *physical* memory. The f_pos points directly to the * memory location. */ static ssize_t read_mem(struct file * file, char * buf, size_t count, loff_t *ppos) { unsigned long p = *ppos; unsigned long end_mem; ssize_t read; end_mem = __pa(high_memory); if (p >= end_mem) return 0; if (count > end_mem - p) count = end_mem - p; read = 0; #if defined(__sparc__) || defined(__mc68000__) /* we don't have page 0 mapped on sparc and m68k.. */ if (p < PAGE_SIZE) { unsigned long sz = PAGE_SIZE-p; if (sz > count) sz = count; if (sz > 0) { if (clear_user(buf, sz)) return -EFAULT; buf += sz; p += sz; count -= sz; read += sz; } } #endif if (copy_to_user(buf, __va(p), count) < 0) return -EFAULT; read += count; *ppos += read; return read; } static ssize_t write_mem(struct file * file, const char * buf, size_t count, loff_t *ppos) { unsigned long p = *ppos; unsigned long end_mem; end_mem = __pa(high_memory); if (p >= end_mem) return 0; if (count > end_mem - p) count = end_mem - p; return do_write_mem(file, __va(p), p, buf, count, ppos); } static int mmap_mem(struct file * file, struct vm_area_struct * vma) { unsigned long offset = vma->vm_offset; if (offset & ~PAGE_MASK) return -ENXIO; #if defined(__i386__) /* * hmm.. This disables high-memory caching, as the XFree86 team * wondered about that at one time. * The surround logic should disable caching for the high device * addresses anyway, but right now this seems still needed. */ if (boot_cpu_data.x86 > 3 && offset >= __pa(high_memory)) pgprot_val(vma->vm_page_prot) |= _PAGE_PCD; #endif #ifdef __powerpc__ if (offset >= __pa(high_memory)) pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE|_PAGE_GUARDED; #endif if (remap_page_range(vma->vm_start, offset, vma->vm_end-vma->vm_start, vma->vm_page_prot)) return -EAGAIN; vma->vm_dentry = dget(file->f_dentry); return 0; } /* * This function reads the *virtual* memory as seen by the kernel. */ static ssize_t read_kmem(struct file *file, char *buf, size_t count, loff_t *ppos) { unsigned long p = *ppos; ssize_t read = 0; ssize_t virtr; if (p < (unsigned long) high_memory) { read = count; if (count > (unsigned long) high_memory - p) read = (unsigned long) high_memory - p; #if defined(__sparc__) || defined(__mc68000__) /* we don't have page 0 mapped on sparc and m68k.. */ if (p < PAGE_SIZE && read > 0) { size_t tmp = PAGE_SIZE - p; if (tmp > read) tmp = read; clear_user(buf, tmp); buf += tmp; p += tmp; read -= tmp; count -= tmp; } #endif copy_to_user(buf, (char *)p, read); p += read; buf += read; count -= read; } virtr = vread(buf, (char *)p, count); if (virtr < 0) return virtr; *ppos += p + virtr; return virtr + read; } /* * This function writes to the *virtual* memory as seen by the kernel. */ static ssize_t write_kmem(struct file * file, const char * buf, size_t count, loff_t *ppos) { unsigned long p = *ppos; if (p >= (unsigned long) high_memory) return 0; if (count > (unsigned long) high_memory - p) count = (unsigned long) high_memory - p; return do_write_mem(file, (void*)p, p, buf, count, ppos); } static ssize_t read_port(struct file * file, char * buf, size_t count, loff_t *ppos) { unsigned long i = *ppos; char *tmp = buf; if (verify_area(VERIFY_WRITE,buf,count)) return -EFAULT; while (count-- > 0 && i < 65536) { if (__put_user(inb(i),tmp) < 0) return -EFAULT; i++; tmp++; } *ppos = i; return tmp-buf; } static ssize_t write_port(struct file * file, const char * buf, size_t count, loff_t *ppos) { unsigned long i = *ppos; const char * tmp = buf; if (verify_area(VERIFY_READ,buf,count)) return -EFAULT; while (count-- > 0 && i < 65536) { char c; if (__get_user(c, tmp)) return -EFAULT; outb(c,i); i++; tmp++; } *ppos = i; return tmp-buf; } static ssize_t read_null(struct file * file, char * buf, size_t count, loff_t *ppos) { return 0; } static ssize_t write_null(struct file * file, const char * buf, size_t count, loff_t *ppos) { return count; } /* * For fun, we are using the MMU for this. */ static inline size_t read_zero_pagealigned(char * buf, size_t size) { struct vm_area_struct * vma; unsigned long addr=(unsigned long)buf; /* For private mappings, just map in zero pages. */ for (vma = find_vma(current->mm, addr); vma; vma = vma->vm_next) { unsigned long count; if (vma->vm_start > addr || (vma->vm_flags & VM_WRITE) == 0) return size; if (vma->vm_flags & VM_SHARED) break; count = vma->vm_end - addr; if (count > size) count = size; flush_cache_range(current->mm, addr, addr + count); zap_page_range(current->mm, addr, count); zeromap_page_range(addr, count, PAGE_COPY); flush_tlb_range(current->mm, addr, addr + count); size -= count; buf += count; addr += count; if (size == 0) return 0; } /* The shared case is hard. Lets do the conventional zeroing. */ do { unsigned long unwritten = clear_user(buf, PAGE_SIZE); if (unwritten) return size + unwritten - PAGE_SIZE; if (need_resched) schedule(); buf += PAGE_SIZE; size -= PAGE_SIZE; } while (size); return size; } static ssize_t read_zero(struct file * file, char * buf, size_t count, loff_t *ppos) { unsigned long left, unwritten, written = 0; if (!count) return 0; if (!access_ok(VERIFY_WRITE, buf, count)) return -EFAULT; left = count; /* do we want to be clever? Arbitrary cut-off */ if (count >= PAGE_SIZE*4) { unsigned long partial; /* How much left of the page? */ partial = (PAGE_SIZE-1) & -(unsigned long) buf; unwritten = clear_user(buf, partial); written = partial - unwritten; if (unwritten) goto out; left -= partial; buf += partial; unwritten = read_zero_pagealigned(buf, left & PAGE_MASK); written += (left & PAGE_MASK) - unwritten; if (unwritten) goto out; buf += left & PAGE_MASK; left &= ~PAGE_MASK; } unwritten = clear_user(buf, left); written += left - unwritten; out: return written ? written : -EFAULT; } static int mmap_zero(struct file * file, struct vm_area_struct * vma) { if (vma->vm_flags & VM_SHARED) return -EINVAL; if (zeromap_page_range(vma->vm_start, vma->vm_end - vma->vm_start, vma->vm_page_prot)) return -EAGAIN; return 0; } static ssize_t write_full(struct file * file, const char * buf, size_t count, loff_t *ppos) { return -ENOSPC; } /* * Special lseek() function for /dev/null and /dev/zero. Most notably, you * can fopen() both devices with "a" now. This was previously impossible. * -- SRB. */ static loff_t null_lseek(struct file * file, loff_t offset, int orig) { return file->f_pos = 0; } /* * The memory devices use the full 32/64 bits of the offset, and so we cannot * check against negative addresses: they are ok. The return value is weird, * though, in that case (0). * * also note that seeking relative to the "end of file" isn't supported: * it has no meaning, so it returns -EINVAL. */ static loff_t memory_lseek(struct file * file, loff_t offset, int orig) { switch (orig) { case 0: file->f_pos = offset; return file->f_pos; case 1: file->f_pos += offset; return file->f_pos; default: return -EINVAL; } if (file->f_pos < 0) return 0; return file->f_pos; } #define mmap_kmem mmap_mem #define zero_lseek null_lseek #define full_lseek null_lseek #define write_zero write_null #define read_full read_zero static struct file_operations mem_fops = { memory_lseek, read_mem, write_mem, NULL, /* mem_readdir */ NULL, /* mem_poll */ NULL, /* mem_ioctl */ mmap_mem, NULL, /* no special open code */ NULL, /* no special release code */ NULL /* fsync */ }; static struct file_operations kmem_fops = { memory_lseek, read_kmem, write_kmem, NULL, /* kmem_readdir */ NULL, /* kmem_poll */ NULL, /* kmem_ioctl */ mmap_kmem, NULL, /* no special open code */ NULL, /* no special release code */ NULL /* fsync */ }; static struct file_operations null_fops = { null_lseek, read_null, write_null, NULL, /* null_readdir */ NULL, /* null_poll */ NULL, /* null_ioctl */ NULL, /* null_mmap */ NULL, /* no special open code */ NULL, /* no special release code */ NULL /* fsync */ }; static struct file_operations port_fops = { memory_lseek, read_port, write_port, NULL, /* port_readdir */ NULL, /* port_poll */ NULL, /* port_ioctl */ NULL, /* port_mmap */ NULL, /* no special open code */ NULL, /* no special release code */ NULL /* fsync */ }; static struct file_operations zero_fops = { zero_lseek, read_zero, write_zero, NULL, /* zero_readdir */ NULL, /* zero_poll */ NULL, /* zero_ioctl */ mmap_zero, NULL, /* no special open code */ NULL /* no special release code */ }; static struct file_operations full_fops = { full_lseek, read_full, write_full, NULL, /* full_readdir */ NULL, /* full_poll */ NULL, /* full_ioctl */ NULL, /* full_mmap */ NULL, /* no special open code */ NULL /* no special release code */ }; static int memory_open(struct inode * inode, struct file * filp) { switch (MINOR(inode->i_rdev)) { case 1: filp->f_op = &mem_fops; break; case 2: filp->f_op = &kmem_fops; break; case 3: filp->f_op = &null_fops; break; case 4: filp->f_op = &port_fops; break; case 5: filp->f_op = &zero_fops; break; case 7: filp->f_op = &full_fops; break; case 8: filp->f_op = &random_fops; break; case 9: filp->f_op = &urandom_fops; break; default: return -ENXIO; } if (filp->f_op && filp->f_op->open) return filp->f_op->open(inode,filp); return 0; } static struct file_operations memory_fops = { NULL, /* lseek */ NULL, /* read */ NULL, /* write */ NULL, /* readdir */ NULL, /* poll */ NULL, /* ioctl */ NULL, /* mmap */ memory_open, /* just a selector for the real open */ NULL, /* release */ NULL /* fsync */ }; __initfunc(int chr_dev_init(void)) { if (register_chrdev(MEM_MAJOR,"mem",&memory_fops)) printk("unable to get major %d for memory devs\n", MEM_MAJOR); rand_initialize(); tty_init(); #ifdef CONFIG_PRINTER lp_init(); #endif #if defined (CONFIG_BUSMOUSE) || defined(CONFIG_UMISC) || \ defined (CONFIG_PSMOUSE) || defined (CONFIG_MS_BUSMOUSE) || \ defined (CONFIG_ATIXL_BUSMOUSE) || defined(CONFIG_SOFT_WATCHDOG) || \ defined (CONFIG_AMIGAMOUSE) || defined (CONFIG_ATARIMOUSE) || \ defined (CONFIG_PCWATCHDOG) || \ defined (CONFIG_APM) || defined (CONFIG_RTC) || \ defined (CONFIG_SUN_MOUSE) || defined (CONFIG_NVRAM) misc_init(); #endif #ifdef CONFIG_SOUND soundcard_init(); #endif #ifdef CONFIG_JOYSTICK /* * Some joysticks only appear when the soundcard they are * connected too is confgured. Keep the sound/joystick ordering. */ js_init(); #endif #if CONFIG_QIC02_TAPE qic02_tape_init(); #endif #if CONFIG_ISDN isdn_init(); #endif #ifdef CONFIG_FTAPE ftape_init(); #endif #ifdef CONFIG_VIDEO_DEV videodev_init(); #endif return 0; } |