[PATCH] ia64: use i386 dmi_scan.c
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / char / mem.c
CommitLineData
1da177e4
LT
1/*
2 * linux/drivers/char/mem.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * Added devfs support.
7 * Jan-11-1998, C. Scott Ananian <cananian@alumni.princeton.edu>
8 * Shared /dev/zero mmaping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com>
9 */
10
11#include <linux/config.h>
12#include <linux/mm.h>
13#include <linux/miscdevice.h>
14#include <linux/slab.h>
15#include <linux/vmalloc.h>
16#include <linux/mman.h>
17#include <linux/random.h>
18#include <linux/init.h>
19#include <linux/raw.h>
20#include <linux/tty.h>
21#include <linux/capability.h>
22#include <linux/smp_lock.h>
23#include <linux/devfs_fs_kernel.h>
24#include <linux/ptrace.h>
25#include <linux/device.h>
50b1fdbd
VG
26#include <linux/highmem.h>
27#include <linux/crash_dump.h>
1da177e4 28#include <linux/backing-dev.h>
315c215c 29#include <linux/bootmem.h>
1da177e4
LT
30
31#include <asm/uaccess.h>
32#include <asm/io.h>
33
34#ifdef CONFIG_IA64
35# include <linux/efi.h>
36#endif
37
1da177e4
LT
38/*
39 * Architectures vary in how they handle caching for addresses
40 * outside of main memory.
41 *
42 */
43static inline int uncached_access(struct file *file, unsigned long addr)
44{
45#if defined(__i386__)
46 /*
47 * On the PPro and successors, the MTRRs are used to set
48 * memory types for physical addresses outside main memory,
49 * so blindly setting PCD or PWT on those pages is wrong.
50 * For Pentiums and earlier, the surround logic should disable
51 * caching for the high addresses through the KEN pin, but
52 * we maintain the tradition of paranoia in this code.
53 */
54 if (file->f_flags & O_SYNC)
55 return 1;
56 return !( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) ||
57 test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) ||
58 test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) ||
59 test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability) )
60 && addr >= __pa(high_memory);
61#elif defined(__x86_64__)
62 /*
63 * This is broken because it can generate memory type aliases,
64 * which can cause cache corruptions
65 * But it is only available for root and we have to be bug-to-bug
66 * compatible with i386.
67 */
68 if (file->f_flags & O_SYNC)
69 return 1;
70 /* same behaviour as i386. PAT always set to cached and MTRRs control the
71 caching behaviour.
72 Hopefully a full PAT implementation will fix that soon. */
73 return 0;
74#elif defined(CONFIG_IA64)
75 /*
76 * On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases.
77 */
78 return !(efi_mem_attributes(addr) & EFI_MEMORY_WB);
79#else
80 /*
81 * Accessing memory above the top the kernel knows about or through a file pointer
82 * that was marked O_SYNC will be done non-cached.
83 */
84 if (file->f_flags & O_SYNC)
85 return 1;
86 return addr >= __pa(high_memory);
87#endif
88}
89
90#ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE
91static inline int valid_phys_addr_range(unsigned long addr, size_t *count)
92{
93 unsigned long end_mem;
94
95 end_mem = __pa(high_memory);
96 if (addr >= end_mem)
97 return 0;
98
99 if (*count > end_mem - addr)
100 *count = end_mem - addr;
101
102 return 1;
103}
80851ef2
BH
104
105static inline int valid_mmap_phys_addr_range(unsigned long addr, size_t *size)
106{
107 return 1;
108}
1da177e4
LT
109#endif
110
111/*
112 * This funcion reads the *physical* memory. The f_pos points directly to the
113 * memory location.
114 */
115static ssize_t read_mem(struct file * file, char __user * buf,
116 size_t count, loff_t *ppos)
117{
118 unsigned long p = *ppos;
119 ssize_t read, sz;
120 char *ptr;
121
122 if (!valid_phys_addr_range(p, &count))
123 return -EFAULT;
124 read = 0;
125#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
126 /* we don't have page 0 mapped on sparc and m68k.. */
127 if (p < PAGE_SIZE) {
128 sz = PAGE_SIZE - p;
129 if (sz > count)
130 sz = count;
131 if (sz > 0) {
132 if (clear_user(buf, sz))
133 return -EFAULT;
134 buf += sz;
135 p += sz;
136 count -= sz;
137 read += sz;
138 }
139 }
140#endif
141
142 while (count > 0) {
143 /*
144 * Handle first page in case it's not aligned
145 */
146 if (-p & (PAGE_SIZE - 1))
147 sz = -p & (PAGE_SIZE - 1);
148 else
149 sz = PAGE_SIZE;
150
151 sz = min_t(unsigned long, sz, count);
152
153 /*
154 * On ia64 if a page has been mapped somewhere as
155 * uncached, then it must also be accessed uncached
156 * by the kernel or data corruption may occur
157 */
158 ptr = xlate_dev_mem_ptr(p);
159
160 if (copy_to_user(buf, ptr, sz))
161 return -EFAULT;
162 buf += sz;
163 p += sz;
164 count -= sz;
165 read += sz;
166 }
167
168 *ppos += read;
169 return read;
170}
171
172static ssize_t write_mem(struct file * file, const char __user * buf,
173 size_t count, loff_t *ppos)
174{
175 unsigned long p = *ppos;
176 ssize_t written, sz;
177 unsigned long copied;
178 void *ptr;
179
180 if (!valid_phys_addr_range(p, &count))
181 return -EFAULT;
182
183 written = 0;
184
185#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
186 /* we don't have page 0 mapped on sparc and m68k.. */
187 if (p < PAGE_SIZE) {
188 unsigned long sz = PAGE_SIZE - p;
189 if (sz > count)
190 sz = count;
191 /* Hmm. Do something? */
192 buf += sz;
193 p += sz;
194 count -= sz;
195 written += sz;
196 }
197#endif
198
199 while (count > 0) {
200 /*
201 * Handle first page in case it's not aligned
202 */
203 if (-p & (PAGE_SIZE - 1))
204 sz = -p & (PAGE_SIZE - 1);
205 else
206 sz = PAGE_SIZE;
207
208 sz = min_t(unsigned long, sz, count);
209
210 /*
211 * On ia64 if a page has been mapped somewhere as
212 * uncached, then it must also be accessed uncached
213 * by the kernel or data corruption may occur
214 */
215 ptr = xlate_dev_mem_ptr(p);
216
217 copied = copy_from_user(ptr, buf, sz);
218 if (copied) {
c654d60e
JB
219 written += sz - copied;
220 if (written)
221 break;
1da177e4
LT
222 return -EFAULT;
223 }
224 buf += sz;
225 p += sz;
226 count -= sz;
227 written += sz;
228 }
229
230 *ppos += written;
231 return written;
232}
233
44ac8413
BH
234#ifndef __HAVE_PHYS_MEM_ACCESS_PROT
235static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
236 unsigned long size, pgprot_t vma_prot)
237{
238#ifdef pgprot_noncached
239 unsigned long offset = pfn << PAGE_SHIFT;
240
241 if (uncached_access(file, offset))
242 return pgprot_noncached(vma_prot);
243#endif
244 return vma_prot;
245}
246#endif
247
1da177e4
LT
248static int mmap_mem(struct file * file, struct vm_area_struct * vma)
249{
80851ef2
BH
250 size_t size = vma->vm_end - vma->vm_start;
251
252 if (!valid_mmap_phys_addr_range(vma->vm_pgoff << PAGE_SHIFT, &size))
253 return -EINVAL;
254
8b150478 255 vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
80851ef2 256 size,
1da177e4 257 vma->vm_page_prot);
1da177e4
LT
258
259 /* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */
260 if (remap_pfn_range(vma,
261 vma->vm_start,
262 vma->vm_pgoff,
80851ef2 263 size,
1da177e4
LT
264 vma->vm_page_prot))
265 return -EAGAIN;
266 return 0;
267}
268
269static int mmap_kmem(struct file * file, struct vm_area_struct * vma)
270{
4bb82551
LT
271 unsigned long pfn;
272
273 /* Turn a kernel-virtual address into a physical page frame */
274 pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT;
275
1da177e4
LT
276 /*
277 * RED-PEN: on some architectures there is more mapped memory
278 * than available in mem_map which pfn_valid checks
279 * for. Perhaps should add a new macro here.
280 *
281 * RED-PEN: vmalloc is not supported right now.
282 */
4bb82551 283 if (!pfn_valid(pfn))
1da177e4 284 return -EIO;
4bb82551
LT
285
286 vma->vm_pgoff = pfn;
1da177e4
LT
287 return mmap_mem(file, vma);
288}
289
50b1fdbd
VG
290#ifdef CONFIG_CRASH_DUMP
291/*
292 * Read memory corresponding to the old kernel.
50b1fdbd 293 */
315c215c 294static ssize_t read_oldmem(struct file *file, char __user *buf,
50b1fdbd
VG
295 size_t count, loff_t *ppos)
296{
315c215c
VG
297 unsigned long pfn, offset;
298 size_t read = 0, csize;
299 int rc = 0;
50b1fdbd 300
72414d3f 301 while (count) {
50b1fdbd 302 pfn = *ppos / PAGE_SIZE;
315c215c
VG
303 if (pfn > saved_max_pfn)
304 return read;
50b1fdbd 305
315c215c
VG
306 offset = (unsigned long)(*ppos % PAGE_SIZE);
307 if (count > PAGE_SIZE - offset)
308 csize = PAGE_SIZE - offset;
309 else
310 csize = count;
50b1fdbd 311
315c215c
VG
312 rc = copy_oldmem_page(pfn, buf, csize, offset, 1);
313 if (rc < 0)
314 return rc;
50b1fdbd
VG
315 buf += csize;
316 *ppos += csize;
317 read += csize;
318 count -= csize;
319 }
50b1fdbd
VG
320 return read;
321}
322#endif
323
1da177e4
LT
324extern long vread(char *buf, char *addr, unsigned long count);
325extern long vwrite(char *buf, char *addr, unsigned long count);
326
327/*
328 * This function reads the *virtual* memory as seen by the kernel.
329 */
330static ssize_t read_kmem(struct file *file, char __user *buf,
331 size_t count, loff_t *ppos)
332{
333 unsigned long p = *ppos;
334 ssize_t low_count, read, sz;
335 char * kbuf; /* k-addr because vread() takes vmlist_lock rwlock */
336
337 read = 0;
338 if (p < (unsigned long) high_memory) {
339 low_count = count;
340 if (count > (unsigned long) high_memory - p)
341 low_count = (unsigned long) high_memory - p;
342
343#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
344 /* we don't have page 0 mapped on sparc and m68k.. */
345 if (p < PAGE_SIZE && low_count > 0) {
346 size_t tmp = PAGE_SIZE - p;
347 if (tmp > low_count) tmp = low_count;
348 if (clear_user(buf, tmp))
349 return -EFAULT;
350 buf += tmp;
351 p += tmp;
352 read += tmp;
353 low_count -= tmp;
354 count -= tmp;
355 }
356#endif
357 while (low_count > 0) {
358 /*
359 * Handle first page in case it's not aligned
360 */
361 if (-p & (PAGE_SIZE - 1))
362 sz = -p & (PAGE_SIZE - 1);
363 else
364 sz = PAGE_SIZE;
365
366 sz = min_t(unsigned long, sz, low_count);
367
368 /*
369 * On ia64 if a page has been mapped somewhere as
370 * uncached, then it must also be accessed uncached
371 * by the kernel or data corruption may occur
372 */
373 kbuf = xlate_dev_kmem_ptr((char *)p);
374
375 if (copy_to_user(buf, kbuf, sz))
376 return -EFAULT;
377 buf += sz;
378 p += sz;
379 read += sz;
380 low_count -= sz;
381 count -= sz;
382 }
383 }
384
385 if (count > 0) {
386 kbuf = (char *)__get_free_page(GFP_KERNEL);
387 if (!kbuf)
388 return -ENOMEM;
389 while (count > 0) {
390 int len = count;
391
392 if (len > PAGE_SIZE)
393 len = PAGE_SIZE;
394 len = vread(kbuf, (char *)p, len);
395 if (!len)
396 break;
397 if (copy_to_user(buf, kbuf, len)) {
398 free_page((unsigned long)kbuf);
399 return -EFAULT;
400 }
401 count -= len;
402 buf += len;
403 read += len;
404 p += len;
405 }
406 free_page((unsigned long)kbuf);
407 }
408 *ppos = p;
409 return read;
410}
411
412
413static inline ssize_t
414do_write_kmem(void *p, unsigned long realp, const char __user * buf,
415 size_t count, loff_t *ppos)
416{
417 ssize_t written, sz;
418 unsigned long copied;
419
420 written = 0;
421#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
422 /* we don't have page 0 mapped on sparc and m68k.. */
423 if (realp < PAGE_SIZE) {
424 unsigned long sz = PAGE_SIZE - realp;
425 if (sz > count)
426 sz = count;
427 /* Hmm. Do something? */
428 buf += sz;
429 p += sz;
430 realp += sz;
431 count -= sz;
432 written += sz;
433 }
434#endif
435
436 while (count > 0) {
437 char *ptr;
438 /*
439 * Handle first page in case it's not aligned
440 */
441 if (-realp & (PAGE_SIZE - 1))
442 sz = -realp & (PAGE_SIZE - 1);
443 else
444 sz = PAGE_SIZE;
445
446 sz = min_t(unsigned long, sz, count);
447
448 /*
449 * On ia64 if a page has been mapped somewhere as
450 * uncached, then it must also be accessed uncached
451 * by the kernel or data corruption may occur
452 */
453 ptr = xlate_dev_kmem_ptr(p);
454
455 copied = copy_from_user(ptr, buf, sz);
456 if (copied) {
c654d60e
JB
457 written += sz - copied;
458 if (written)
459 break;
1da177e4
LT
460 return -EFAULT;
461 }
462 buf += sz;
463 p += sz;
464 realp += sz;
465 count -= sz;
466 written += sz;
467 }
468
469 *ppos += written;
470 return written;
471}
472
473
474/*
475 * This function writes to the *virtual* memory as seen by the kernel.
476 */
477static ssize_t write_kmem(struct file * file, const char __user * buf,
478 size_t count, loff_t *ppos)
479{
480 unsigned long p = *ppos;
481 ssize_t wrote = 0;
482 ssize_t virtr = 0;
483 ssize_t written;
484 char * kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */
485
486 if (p < (unsigned long) high_memory) {
487
488 wrote = count;
489 if (count > (unsigned long) high_memory - p)
490 wrote = (unsigned long) high_memory - p;
491
492 written = do_write_kmem((void*)p, p, buf, wrote, ppos);
493 if (written != wrote)
494 return written;
495 wrote = written;
496 p += wrote;
497 buf += wrote;
498 count -= wrote;
499 }
500
501 if (count > 0) {
502 kbuf = (char *)__get_free_page(GFP_KERNEL);
503 if (!kbuf)
504 return wrote ? wrote : -ENOMEM;
505 while (count > 0) {
506 int len = count;
507
508 if (len > PAGE_SIZE)
509 len = PAGE_SIZE;
510 if (len) {
511 written = copy_from_user(kbuf, buf, len);
512 if (written) {
c654d60e
JB
513 if (wrote + virtr)
514 break;
1da177e4 515 free_page((unsigned long)kbuf);
c654d60e 516 return -EFAULT;
1da177e4
LT
517 }
518 }
519 len = vwrite(kbuf, (char *)p, len);
520 count -= len;
521 buf += len;
522 virtr += len;
523 p += len;
524 }
525 free_page((unsigned long)kbuf);
526 }
527
528 *ppos = p;
529 return virtr + wrote;
530}
531
ee2cdece 532#if defined(CONFIG_ISA) || !defined(__mc68000__)
1da177e4
LT
533static ssize_t read_port(struct file * file, char __user * buf,
534 size_t count, loff_t *ppos)
535{
536 unsigned long i = *ppos;
537 char __user *tmp = buf;
538
539 if (!access_ok(VERIFY_WRITE, buf, count))
540 return -EFAULT;
541 while (count-- > 0 && i < 65536) {
542 if (__put_user(inb(i),tmp) < 0)
543 return -EFAULT;
544 i++;
545 tmp++;
546 }
547 *ppos = i;
548 return tmp-buf;
549}
550
551static ssize_t write_port(struct file * file, const char __user * buf,
552 size_t count, loff_t *ppos)
553{
554 unsigned long i = *ppos;
555 const char __user * tmp = buf;
556
557 if (!access_ok(VERIFY_READ,buf,count))
558 return -EFAULT;
559 while (count-- > 0 && i < 65536) {
560 char c;
c654d60e
JB
561 if (__get_user(c, tmp)) {
562 if (tmp > buf)
563 break;
1da177e4 564 return -EFAULT;
c654d60e 565 }
1da177e4
LT
566 outb(c,i);
567 i++;
568 tmp++;
569 }
570 *ppos = i;
571 return tmp-buf;
572}
573#endif
574
575static ssize_t read_null(struct file * file, char __user * buf,
576 size_t count, loff_t *ppos)
577{
578 return 0;
579}
580
581static ssize_t write_null(struct file * file, const char __user * buf,
582 size_t count, loff_t *ppos)
583{
584 return count;
585}
586
587#ifdef CONFIG_MMU
588/*
589 * For fun, we are using the MMU for this.
590 */
591static inline size_t read_zero_pagealigned(char __user * buf, size_t size)
592{
593 struct mm_struct *mm;
594 struct vm_area_struct * vma;
595 unsigned long addr=(unsigned long)buf;
596
597 mm = current->mm;
598 /* Oops, this was forgotten before. -ben */
599 down_read(&mm->mmap_sem);
600
601 /* For private mappings, just map in zero pages. */
602 for (vma = find_vma(mm, addr); vma; vma = vma->vm_next) {
603 unsigned long count;
604
605 if (vma->vm_start > addr || (vma->vm_flags & VM_WRITE) == 0)
606 goto out_up;
6aab341e 607 if (vma->vm_flags & (VM_SHARED | VM_HUGETLB))
1da177e4
LT
608 break;
609 count = vma->vm_end - addr;
610 if (count > size)
611 count = size;
612
613 zap_page_range(vma, addr, count, NULL);
614 zeromap_page_range(vma, addr, count, PAGE_COPY);
615
616 size -= count;
617 buf += count;
618 addr += count;
619 if (size == 0)
620 goto out_up;
621 }
622
623 up_read(&mm->mmap_sem);
624
625 /* The shared case is hard. Let's do the conventional zeroing. */
626 do {
627 unsigned long unwritten = clear_user(buf, PAGE_SIZE);
628 if (unwritten)
629 return size + unwritten - PAGE_SIZE;
630 cond_resched();
631 buf += PAGE_SIZE;
632 size -= PAGE_SIZE;
633 } while (size);
634
635 return size;
636out_up:
637 up_read(&mm->mmap_sem);
638 return size;
639}
640
641static ssize_t read_zero(struct file * file, char __user * buf,
642 size_t count, loff_t *ppos)
643{
644 unsigned long left, unwritten, written = 0;
645
646 if (!count)
647 return 0;
648
649 if (!access_ok(VERIFY_WRITE, buf, count))
650 return -EFAULT;
651
652 left = count;
653
654 /* do we want to be clever? Arbitrary cut-off */
655 if (count >= PAGE_SIZE*4) {
656 unsigned long partial;
657
658 /* How much left of the page? */
659 partial = (PAGE_SIZE-1) & -(unsigned long) buf;
660 unwritten = clear_user(buf, partial);
661 written = partial - unwritten;
662 if (unwritten)
663 goto out;
664 left -= partial;
665 buf += partial;
666 unwritten = read_zero_pagealigned(buf, left & PAGE_MASK);
667 written += (left & PAGE_MASK) - unwritten;
668 if (unwritten)
669 goto out;
670 buf += left & PAGE_MASK;
671 left &= ~PAGE_MASK;
672 }
673 unwritten = clear_user(buf, left);
674 written += left - unwritten;
675out:
676 return written ? written : -EFAULT;
677}
678
679static int mmap_zero(struct file * file, struct vm_area_struct * vma)
680{
681 if (vma->vm_flags & VM_SHARED)
682 return shmem_zero_setup(vma);
683 if (zeromap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start, vma->vm_page_prot))
684 return -EAGAIN;
685 return 0;
686}
687#else /* CONFIG_MMU */
688static ssize_t read_zero(struct file * file, char * buf,
689 size_t count, loff_t *ppos)
690{
691 size_t todo = count;
692
693 while (todo) {
694 size_t chunk = todo;
695
696 if (chunk > 4096)
697 chunk = 4096; /* Just for latency reasons */
698 if (clear_user(buf, chunk))
699 return -EFAULT;
700 buf += chunk;
701 todo -= chunk;
702 cond_resched();
703 }
704 return count;
705}
706
707static int mmap_zero(struct file * file, struct vm_area_struct * vma)
708{
709 return -ENOSYS;
710}
711#endif /* CONFIG_MMU */
712
713static ssize_t write_full(struct file * file, const char __user * buf,
714 size_t count, loff_t *ppos)
715{
716 return -ENOSPC;
717}
718
719/*
720 * Special lseek() function for /dev/null and /dev/zero. Most notably, you
721 * can fopen() both devices with "a" now. This was previously impossible.
722 * -- SRB.
723 */
724
725static loff_t null_lseek(struct file * file, loff_t offset, int orig)
726{
727 return file->f_pos = 0;
728}
729
730/*
731 * The memory devices use the full 32/64 bits of the offset, and so we cannot
732 * check against negative addresses: they are ok. The return value is weird,
733 * though, in that case (0).
734 *
735 * also note that seeking relative to the "end of file" isn't supported:
736 * it has no meaning, so it returns -EINVAL.
737 */
738static loff_t memory_lseek(struct file * file, loff_t offset, int orig)
739{
740 loff_t ret;
741
1b1dcc1b 742 mutex_lock(&file->f_dentry->d_inode->i_mutex);
1da177e4
LT
743 switch (orig) {
744 case 0:
745 file->f_pos = offset;
746 ret = file->f_pos;
747 force_successful_syscall_return();
748 break;
749 case 1:
750 file->f_pos += offset;
751 ret = file->f_pos;
752 force_successful_syscall_return();
753 break;
754 default:
755 ret = -EINVAL;
756 }
1b1dcc1b 757 mutex_unlock(&file->f_dentry->d_inode->i_mutex);
1da177e4
LT
758 return ret;
759}
760
761static int open_port(struct inode * inode, struct file * filp)
762{
763 return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
764}
765
766#define zero_lseek null_lseek
767#define full_lseek null_lseek
768#define write_zero write_null
769#define read_full read_zero
770#define open_mem open_port
771#define open_kmem open_mem
50b1fdbd 772#define open_oldmem open_mem
1da177e4
LT
773
774static struct file_operations mem_fops = {
775 .llseek = memory_lseek,
776 .read = read_mem,
777 .write = write_mem,
778 .mmap = mmap_mem,
779 .open = open_mem,
780};
781
782static struct file_operations kmem_fops = {
783 .llseek = memory_lseek,
784 .read = read_kmem,
785 .write = write_kmem,
786 .mmap = mmap_kmem,
787 .open = open_kmem,
788};
789
790static struct file_operations null_fops = {
791 .llseek = null_lseek,
792 .read = read_null,
793 .write = write_null,
794};
795
ee2cdece 796#if defined(CONFIG_ISA) || !defined(__mc68000__)
1da177e4
LT
797static struct file_operations port_fops = {
798 .llseek = memory_lseek,
799 .read = read_port,
800 .write = write_port,
801 .open = open_port,
802};
803#endif
804
805static struct file_operations zero_fops = {
806 .llseek = zero_lseek,
807 .read = read_zero,
808 .write = write_zero,
809 .mmap = mmap_zero,
810};
811
812static struct backing_dev_info zero_bdi = {
813 .capabilities = BDI_CAP_MAP_COPY,
814};
815
816static struct file_operations full_fops = {
817 .llseek = full_lseek,
818 .read = read_full,
819 .write = write_full,
820};
821
50b1fdbd
VG
822#ifdef CONFIG_CRASH_DUMP
823static struct file_operations oldmem_fops = {
824 .read = read_oldmem,
825 .open = open_oldmem,
826};
827#endif
828
1da177e4
LT
829static ssize_t kmsg_write(struct file * file, const char __user * buf,
830 size_t count, loff_t *ppos)
831{
832 char *tmp;
cd140a5c 833 ssize_t ret;
1da177e4
LT
834
835 tmp = kmalloc(count + 1, GFP_KERNEL);
836 if (tmp == NULL)
837 return -ENOMEM;
838 ret = -EFAULT;
839 if (!copy_from_user(tmp, buf, count)) {
840 tmp[count] = 0;
841 ret = printk("%s", tmp);
cd140a5c
GC
842 if (ret > count)
843 /* printk can add a prefix */
844 ret = count;
1da177e4
LT
845 }
846 kfree(tmp);
847 return ret;
848}
849
850static struct file_operations kmsg_fops = {
851 .write = kmsg_write,
852};
853
854static int memory_open(struct inode * inode, struct file * filp)
855{
856 switch (iminor(inode)) {
857 case 1:
858 filp->f_op = &mem_fops;
859 break;
860 case 2:
861 filp->f_op = &kmem_fops;
862 break;
863 case 3:
864 filp->f_op = &null_fops;
865 break;
ee2cdece 866#if defined(CONFIG_ISA) || !defined(__mc68000__)
1da177e4
LT
867 case 4:
868 filp->f_op = &port_fops;
869 break;
870#endif
871 case 5:
872 filp->f_mapping->backing_dev_info = &zero_bdi;
873 filp->f_op = &zero_fops;
874 break;
875 case 7:
876 filp->f_op = &full_fops;
877 break;
878 case 8:
879 filp->f_op = &random_fops;
880 break;
881 case 9:
882 filp->f_op = &urandom_fops;
883 break;
884 case 11:
885 filp->f_op = &kmsg_fops;
886 break;
50b1fdbd
VG
887#ifdef CONFIG_CRASH_DUMP
888 case 12:
889 filp->f_op = &oldmem_fops;
890 break;
891#endif
1da177e4
LT
892 default:
893 return -ENXIO;
894 }
895 if (filp->f_op && filp->f_op->open)
896 return filp->f_op->open(inode,filp);
897 return 0;
898}
899
900static struct file_operations memory_fops = {
901 .open = memory_open, /* just a selector for the real open */
902};
903
904static const struct {
905 unsigned int minor;
906 char *name;
907 umode_t mode;
908 struct file_operations *fops;
909} devlist[] = { /* list of minor devices */
910 {1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops},
911 {2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops},
912 {3, "null", S_IRUGO | S_IWUGO, &null_fops},
ee2cdece 913#if defined(CONFIG_ISA) || !defined(__mc68000__)
1da177e4
LT
914 {4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops},
915#endif
916 {5, "zero", S_IRUGO | S_IWUGO, &zero_fops},
917 {7, "full", S_IRUGO | S_IWUGO, &full_fops},
918 {8, "random", S_IRUGO | S_IWUSR, &random_fops},
919 {9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops},
920 {11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops},
50b1fdbd
VG
921#ifdef CONFIG_CRASH_DUMP
922 {12,"oldmem", S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops},
923#endif
1da177e4
LT
924};
925
ca8eca68 926static struct class *mem_class;
1da177e4
LT
927
928static int __init chr_dev_init(void)
929{
930 int i;
931
932 if (register_chrdev(MEM_MAJOR,"mem",&memory_fops))
933 printk("unable to get major %d for memory devs\n", MEM_MAJOR);
934
ca8eca68 935 mem_class = class_create(THIS_MODULE, "mem");
1da177e4 936 for (i = 0; i < ARRAY_SIZE(devlist); i++) {
53f46542
GKH
937 class_device_create(mem_class, NULL,
938 MKDEV(MEM_MAJOR, devlist[i].minor),
1da177e4
LT
939 NULL, devlist[i].name);
940 devfs_mk_cdev(MKDEV(MEM_MAJOR, devlist[i].minor),
941 S_IFCHR | devlist[i].mode, devlist[i].name);
942 }
943
944 return 0;
945}
946
947fs_initcall(chr_dev_init);