blob: 9a6b63783a94dd19a4f49133fd94265fad98c19c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/drivers/char/mem.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
Andrew Mortond7d4d842010-03-10 15:21:52 -08006 * Added devfs support.
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * Jan-11-1998, C. Scott Ananian <cananian@alumni.princeton.edu>
André Goddard Rosaaf901ca2009-11-14 13:09:05 -02008 * Shared /dev/zero mmapping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com>
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 */
10
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/mm.h>
12#include <linux/miscdevice.h>
13#include <linux/slab.h>
14#include <linux/vmalloc.h>
15#include <linux/mman.h>
16#include <linux/random.h>
17#include <linux/init.h>
18#include <linux/raw.h>
19#include <linux/tty.h>
20#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/ptrace.h>
22#include <linux/device.h>
Vivek Goyal50b1fdb2005-06-25 14:58:23 -070023#include <linux/highmem.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/backing-dev.h>
Jens Axboed6b29d72007-06-04 09:59:47 +020025#include <linux/splice.h>
Linus Torvaldsb8a3ad52006-10-13 08:42:10 -070026#include <linux/pfn.h>
Paul Gortmaker66300e62011-07-10 12:14:53 -040027#include <linux/export.h>
Haren Mynenie1612de2012-07-11 15:18:44 +100028#include <linux/io.h>
Kent Overstreeta27bb332013-05-07 16:19:08 -070029#include <linux/aio.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
31#include <asm/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
33#ifdef CONFIG_IA64
34# include <linux/efi.h>
35#endif
36
Haren Mynenie1612de2012-07-11 15:18:44 +100037#define DEVPORT_MINOR 4
38
Wu Fengguangf2223182009-12-14 17:58:07 -080039static inline unsigned long size_inside_page(unsigned long start,
40 unsigned long size)
41{
42 unsigned long sz;
43
Wu Fengguang7fabadd2009-12-14 17:58:09 -080044 sz = PAGE_SIZE - (start & (PAGE_SIZE - 1));
Wu Fengguangf2223182009-12-14 17:58:07 -080045
Wu Fengguang7fabadd2009-12-14 17:58:09 -080046 return min(sz, size);
Wu Fengguangf2223182009-12-14 17:58:07 -080047}
48
Linus Torvalds1da177e2005-04-16 15:20:36 -070049#ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE
Cyril Chemparathy7e6735c2012-09-12 14:05:58 -040050static inline int valid_phys_addr_range(phys_addr_t addr, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -070051{
Changli Gaocfaf346c2011-03-23 16:42:58 -070052 return addr + count <= __pa(high_memory);
Linus Torvalds1da177e2005-04-16 15:20:36 -070053}
Bjorn Helgaas80851ef2006-01-08 01:04:13 -080054
Lennert Buytenhek06c67be2006-07-10 04:45:27 -070055static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
Bjorn Helgaas80851ef2006-01-08 01:04:13 -080056{
57 return 1;
58}
Linus Torvalds1da177e2005-04-16 15:20:36 -070059#endif
60
Ingo Molnard0926332008-07-18 00:26:59 +020061#ifdef CONFIG_STRICT_DEVMEM
Venki Pallipadie2beb3e2008-03-06 23:01:47 -080062static inline int range_is_allowed(unsigned long pfn, unsigned long size)
Arjan van de Venae531c22008-04-24 23:40:47 +020063{
Venki Pallipadie2beb3e2008-03-06 23:01:47 -080064 u64 from = ((u64)pfn) << PAGE_SHIFT;
65 u64 to = from + size;
66 u64 cursor = from;
Arjan van de Venae531c22008-04-24 23:40:47 +020067
Venki Pallipadie2beb3e2008-03-06 23:01:47 -080068 while (cursor < to) {
69 if (!devmem_is_allowed(pfn)) {
70 printk(KERN_INFO
71 "Program %s tried to access /dev/mem between %Lx->%Lx.\n",
Arjan van de Venae531c22008-04-24 23:40:47 +020072 current->comm, from, to);
73 return 0;
74 }
Venki Pallipadie2beb3e2008-03-06 23:01:47 -080075 cursor += PAGE_SIZE;
76 pfn++;
Arjan van de Venae531c22008-04-24 23:40:47 +020077 }
78 return 1;
79}
80#else
Venki Pallipadie2beb3e2008-03-06 23:01:47 -080081static inline int range_is_allowed(unsigned long pfn, unsigned long size)
Arjan van de Venae531c22008-04-24 23:40:47 +020082{
83 return 1;
84}
85#endif
86
Thierry Reding4707a342014-07-28 17:20:33 +020087#ifndef unxlate_dev_mem_ptr
88#define unxlate_dev_mem_ptr unxlate_dev_mem_ptr
89void __weak unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
venkatesh.pallipadi@intel.come045fb22008-03-18 17:00:15 -070090{
91}
Thierry Reding4707a342014-07-28 17:20:33 +020092#endif
venkatesh.pallipadi@intel.come045fb22008-03-18 17:00:15 -070093
Linus Torvalds1da177e2005-04-16 15:20:36 -070094/*
Andrew Mortond7d4d842010-03-10 15:21:52 -080095 * This funcion reads the *physical* memory. The f_pos points directly to the
96 * memory location.
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 */
Andrew Mortond7d4d842010-03-10 15:21:52 -080098static ssize_t read_mem(struct file *file, char __user *buf,
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 size_t count, loff_t *ppos)
100{
Cyril Chemparathy7e6735c2012-09-12 14:05:58 -0400101 phys_addr_t p = *ppos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 ssize_t read, sz;
Thierry Reding4707a342014-07-28 17:20:33 +0200103 void *ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
Petr Tesarik08d2d002014-01-30 09:48:02 +0100105 if (p != *ppos)
106 return 0;
107
Bjorn Helgaas136939a2006-03-26 01:37:05 -0800108 if (!valid_phys_addr_range(p, count))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 return -EFAULT;
110 read = 0;
111#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
112 /* we don't have page 0 mapped on sparc and m68k.. */
113 if (p < PAGE_SIZE) {
Wu Fengguang7fabadd2009-12-14 17:58:09 -0800114 sz = size_inside_page(p, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 if (sz > 0) {
116 if (clear_user(buf, sz))
117 return -EFAULT;
Andrew Mortond7d4d842010-03-10 15:21:52 -0800118 buf += sz;
119 p += sz;
120 count -= sz;
121 read += sz;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 }
123 }
124#endif
125
126 while (count > 0) {
Wu Fengguangfa29e972009-12-14 17:58:08 -0800127 unsigned long remaining;
128
Wu Fengguangf2223182009-12-14 17:58:07 -0800129 sz = size_inside_page(p, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
venkatesh.pallipadi@intel.come045fb22008-03-18 17:00:15 -0700131 if (!range_is_allowed(p >> PAGE_SHIFT, count))
132 return -EPERM;
133
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 /*
Andrew Mortond7d4d842010-03-10 15:21:52 -0800135 * On ia64 if a page has been mapped somewhere as uncached, then
136 * it must also be accessed uncached by the kernel or data
137 * corruption may occur.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 */
139 ptr = xlate_dev_mem_ptr(p);
venkatesh.pallipadi@intel.come045fb22008-03-18 17:00:15 -0700140 if (!ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 return -EFAULT;
venkatesh.pallipadi@intel.come045fb22008-03-18 17:00:15 -0700142
Wu Fengguangfa29e972009-12-14 17:58:08 -0800143 remaining = copy_to_user(buf, ptr, sz);
venkatesh.pallipadi@intel.come045fb22008-03-18 17:00:15 -0700144 unxlate_dev_mem_ptr(p, ptr);
Wu Fengguangfa29e972009-12-14 17:58:08 -0800145 if (remaining)
146 return -EFAULT;
venkatesh.pallipadi@intel.come045fb22008-03-18 17:00:15 -0700147
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 buf += sz;
149 p += sz;
150 count -= sz;
151 read += sz;
152 }
153
154 *ppos += read;
155 return read;
156}
157
Andrew Mortond7d4d842010-03-10 15:21:52 -0800158static ssize_t write_mem(struct file *file, const char __user *buf,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 size_t count, loff_t *ppos)
160{
Cyril Chemparathy7e6735c2012-09-12 14:05:58 -0400161 phys_addr_t p = *ppos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 ssize_t written, sz;
163 unsigned long copied;
164 void *ptr;
165
Petr Tesarik08d2d002014-01-30 09:48:02 +0100166 if (p != *ppos)
167 return -EFBIG;
168
Bjorn Helgaas136939a2006-03-26 01:37:05 -0800169 if (!valid_phys_addr_range(p, count))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 return -EFAULT;
171
172 written = 0;
173
174#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
175 /* we don't have page 0 mapped on sparc and m68k.. */
176 if (p < PAGE_SIZE) {
Wu Fengguang7fabadd2009-12-14 17:58:09 -0800177 sz = size_inside_page(p, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 /* Hmm. Do something? */
179 buf += sz;
180 p += sz;
181 count -= sz;
182 written += sz;
183 }
184#endif
185
186 while (count > 0) {
Wu Fengguangf2223182009-12-14 17:58:07 -0800187 sz = size_inside_page(p, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
venkatesh.pallipadi@intel.come045fb22008-03-18 17:00:15 -0700189 if (!range_is_allowed(p >> PAGE_SHIFT, sz))
190 return -EPERM;
191
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 /*
Andrew Mortond7d4d842010-03-10 15:21:52 -0800193 * On ia64 if a page has been mapped somewhere as uncached, then
194 * it must also be accessed uncached by the kernel or data
195 * corruption may occur.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 */
197 ptr = xlate_dev_mem_ptr(p);
venkatesh.pallipadi@intel.come045fb22008-03-18 17:00:15 -0700198 if (!ptr) {
Jan Beulichc654d602006-03-25 03:07:31 -0800199 if (written)
200 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 return -EFAULT;
202 }
venkatesh.pallipadi@intel.come045fb22008-03-18 17:00:15 -0700203
204 copied = copy_from_user(ptr, buf, sz);
Wu Fengguangfa29e972009-12-14 17:58:08 -0800205 unxlate_dev_mem_ptr(p, ptr);
venkatesh.pallipadi@intel.come045fb22008-03-18 17:00:15 -0700206 if (copied) {
207 written += sz - copied;
venkatesh.pallipadi@intel.come045fb22008-03-18 17:00:15 -0700208 if (written)
209 break;
210 return -EFAULT;
211 }
212
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 buf += sz;
214 p += sz;
215 count -= sz;
216 written += sz;
217 }
218
219 *ppos += written;
220 return written;
221}
222
Andrew Mortond7d4d842010-03-10 15:21:52 -0800223int __weak phys_mem_access_prot_allowed(struct file *file,
venkatesh.pallipadi@intel.comf0970c12008-03-18 17:00:20 -0700224 unsigned long pfn, unsigned long size, pgprot_t *vma_prot)
225{
226 return 1;
227}
228
Bjorn Helgaas44ac8412006-01-08 01:04:10 -0800229#ifndef __HAVE_PHYS_MEM_ACCESS_PROT
Andrew Mortond7d4d842010-03-10 15:21:52 -0800230
231/*
232 * Architectures vary in how they handle caching for addresses
233 * outside of main memory.
234 *
235 */
David Howellsea56f412010-04-06 14:35:08 -0700236#ifdef pgprot_noncached
Cyril Chemparathy7e6735c2012-09-12 14:05:58 -0400237static int uncached_access(struct file *file, phys_addr_t addr)
Andrew Mortond7d4d842010-03-10 15:21:52 -0800238{
239#if defined(CONFIG_IA64)
240 /*
241 * On ia64, we ignore O_DSYNC because we cannot tolerate memory
242 * attribute aliases.
243 */
244 return !(efi_mem_attributes(addr) & EFI_MEMORY_WB);
245#elif defined(CONFIG_MIPS)
246 {
247 extern int __uncached_access(struct file *file,
248 unsigned long addr);
249
250 return __uncached_access(file, addr);
251 }
252#else
253 /*
254 * Accessing memory above the top the kernel knows about or through a
255 * file pointer
256 * that was marked O_DSYNC will be done non-cached.
257 */
258 if (file->f_flags & O_DSYNC)
259 return 1;
260 return addr >= __pa(high_memory);
261#endif
262}
David Howellsea56f412010-04-06 14:35:08 -0700263#endif
Andrew Mortond7d4d842010-03-10 15:21:52 -0800264
Bjorn Helgaas44ac8412006-01-08 01:04:10 -0800265static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
266 unsigned long size, pgprot_t vma_prot)
267{
268#ifdef pgprot_noncached
Cyril Chemparathy7e6735c2012-09-12 14:05:58 -0400269 phys_addr_t offset = pfn << PAGE_SHIFT;
Bjorn Helgaas44ac8412006-01-08 01:04:10 -0800270
271 if (uncached_access(file, offset))
272 return pgprot_noncached(vma_prot);
273#endif
274 return vma_prot;
275}
276#endif
277
David Howells5da61852006-09-27 01:50:16 -0700278#ifndef CONFIG_MMU
279static unsigned long get_unmapped_area_mem(struct file *file,
280 unsigned long addr,
281 unsigned long len,
282 unsigned long pgoff,
283 unsigned long flags)
284{
285 if (!valid_mmap_phys_addr_range(pgoff, len))
286 return (unsigned long) -EINVAL;
Benjamin Herrenschmidt8a932582007-04-16 22:53:16 -0700287 return pgoff << PAGE_SHIFT;
David Howells5da61852006-09-27 01:50:16 -0700288}
289
Christoph Hellwigb4caecd2015-01-14 10:42:32 +0100290/* permit direct mmap, for read, write or exec */
291static unsigned memory_mmap_capabilities(struct file *file)
292{
293 return NOMMU_MAP_DIRECT |
294 NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC;
295}
296
297static unsigned zero_mmap_capabilities(struct file *file)
298{
299 return NOMMU_MAP_COPY;
300}
301
David Howells5da61852006-09-27 01:50:16 -0700302/* can't do an in-place private mapping if there's no MMU */
303static inline int private_mapping_ok(struct vm_area_struct *vma)
304{
305 return vma->vm_flags & VM_MAYSHARE;
306}
307#else
David Howells5da61852006-09-27 01:50:16 -0700308
309static inline int private_mapping_ok(struct vm_area_struct *vma)
310{
311 return 1;
312}
313#endif
314
Alexey Dobriyanf0f37e22009-09-27 22:29:37 +0400315static const struct vm_operations_struct mmap_mem_ops = {
Rik van Riel7ae8ed52008-07-23 21:27:07 -0700316#ifdef CONFIG_HAVE_IOREMAP_PROT
317 .access = generic_access_phys
318#endif
venkatesh.pallipadi@intel.come7f260a2008-03-18 17:00:21 -0700319};
320
Andrew Mortond7d4d842010-03-10 15:21:52 -0800321static int mmap_mem(struct file *file, struct vm_area_struct *vma)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322{
Bjorn Helgaas80851ef2006-01-08 01:04:13 -0800323 size_t size = vma->vm_end - vma->vm_start;
324
Lennert Buytenhek06c67be2006-07-10 04:45:27 -0700325 if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size))
Bjorn Helgaas80851ef2006-01-08 01:04:13 -0800326 return -EINVAL;
327
David Howells5da61852006-09-27 01:50:16 -0700328 if (!private_mapping_ok(vma))
329 return -ENOSYS;
330
Venki Pallipadie2beb3e2008-03-06 23:01:47 -0800331 if (!range_is_allowed(vma->vm_pgoff, size))
332 return -EPERM;
333
venkatesh.pallipadi@intel.comf0970c12008-03-18 17:00:20 -0700334 if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size,
335 &vma->vm_page_prot))
336 return -EINVAL;
337
Roland Dreier8b150472005-10-28 17:46:18 -0700338 vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
Bjorn Helgaas80851ef2006-01-08 01:04:13 -0800339 size,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 vma->vm_page_prot);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
venkatesh.pallipadi@intel.come7f260a2008-03-18 17:00:21 -0700342 vma->vm_ops = &mmap_mem_ops;
343
Konstantin Khlebnikov314e51b2012-10-08 16:29:02 -0700344 /* Remap-pfn-range will mark the range VM_IO */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 if (remap_pfn_range(vma,
346 vma->vm_start,
347 vma->vm_pgoff,
Bjorn Helgaas80851ef2006-01-08 01:04:13 -0800348 size,
venkatesh.pallipadi@intel.come7f260a2008-03-18 17:00:21 -0700349 vma->vm_page_prot)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 return -EAGAIN;
venkatesh.pallipadi@intel.come7f260a2008-03-18 17:00:21 -0700351 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 return 0;
353}
354
Arjan van de Venb781ecb2008-04-29 00:58:34 -0700355#ifdef CONFIG_DEVKMEM
Andrew Mortond7d4d842010-03-10 15:21:52 -0800356static int mmap_kmem(struct file *file, struct vm_area_struct *vma)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357{
Linus Torvalds4bb82552005-08-13 14:22:59 -0700358 unsigned long pfn;
359
Linus Torvalds6d3154c2007-01-22 08:53:24 -0800360 /* Turn a kernel-virtual address into a physical page frame */
361 pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT;
Linus Torvalds4bb82552005-08-13 14:22:59 -0700362
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 /*
Andrew Mortond7d4d842010-03-10 15:21:52 -0800364 * RED-PEN: on some architectures there is more mapped memory than
365 * available in mem_map which pfn_valid checks for. Perhaps should add a
366 * new macro here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 *
368 * RED-PEN: vmalloc is not supported right now.
369 */
Linus Torvalds4bb82552005-08-13 14:22:59 -0700370 if (!pfn_valid(pfn))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 return -EIO;
Linus Torvalds4bb82552005-08-13 14:22:59 -0700372
373 vma->vm_pgoff = pfn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 return mmap_mem(file, vma);
375}
Arjan van de Venb781ecb2008-04-29 00:58:34 -0700376#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377
Arjan van de Venb781ecb2008-04-29 00:58:34 -0700378#ifdef CONFIG_DEVKMEM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379/*
380 * This function reads the *virtual* memory as seen by the kernel.
381 */
Andrew Mortond7d4d842010-03-10 15:21:52 -0800382static ssize_t read_kmem(struct file *file, char __user *buf,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 size_t count, loff_t *ppos)
384{
385 unsigned long p = *ppos;
386 ssize_t low_count, read, sz;
Hans Grob890537b2013-02-06 11:37:20 +0100387 char *kbuf; /* k-addr because vread() takes vmlist_lock rwlock */
KAMEZAWA Hiroyuki325fda72010-02-02 13:44:05 -0800388 int err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389
390 read = 0;
391 if (p < (unsigned long) high_memory) {
392 low_count = count;
Andrew Mortond7d4d842010-03-10 15:21:52 -0800393 if (count > (unsigned long)high_memory - p)
394 low_count = (unsigned long)high_memory - p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395
396#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
397 /* we don't have page 0 mapped on sparc and m68k.. */
398 if (p < PAGE_SIZE && low_count > 0) {
Wu Fengguang7fabadd2009-12-14 17:58:09 -0800399 sz = size_inside_page(p, low_count);
400 if (clear_user(buf, sz))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 return -EFAULT;
Wu Fengguang7fabadd2009-12-14 17:58:09 -0800402 buf += sz;
403 p += sz;
404 read += sz;
405 low_count -= sz;
406 count -= sz;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 }
408#endif
409 while (low_count > 0) {
Wu Fengguangf2223182009-12-14 17:58:07 -0800410 sz = size_inside_page(p, low_count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411
412 /*
413 * On ia64 if a page has been mapped somewhere as
414 * uncached, then it must also be accessed uncached
415 * by the kernel or data corruption may occur
416 */
Thierry Reding4707a342014-07-28 17:20:33 +0200417 kbuf = xlate_dev_kmem_ptr((void *)p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418
419 if (copy_to_user(buf, kbuf, sz))
420 return -EFAULT;
421 buf += sz;
422 p += sz;
423 read += sz;
424 low_count -= sz;
425 count -= sz;
426 }
427 }
428
429 if (count > 0) {
430 kbuf = (char *)__get_free_page(GFP_KERNEL);
431 if (!kbuf)
432 return -ENOMEM;
433 while (count > 0) {
Wu Fengguang80ad89a2009-12-14 17:58:10 -0800434 sz = size_inside_page(p, count);
KAMEZAWA Hiroyuki325fda72010-02-02 13:44:05 -0800435 if (!is_vmalloc_or_module_addr((void *)p)) {
436 err = -ENXIO;
437 break;
438 }
Wu Fengguang80ad89a2009-12-14 17:58:10 -0800439 sz = vread(kbuf, (char *)p, sz);
440 if (!sz)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 break;
Wu Fengguang80ad89a2009-12-14 17:58:10 -0800442 if (copy_to_user(buf, kbuf, sz)) {
KAMEZAWA Hiroyuki325fda72010-02-02 13:44:05 -0800443 err = -EFAULT;
444 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 }
Wu Fengguang80ad89a2009-12-14 17:58:10 -0800446 count -= sz;
447 buf += sz;
448 read += sz;
449 p += sz;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 }
451 free_page((unsigned long)kbuf);
452 }
KAMEZAWA Hiroyuki325fda72010-02-02 13:44:05 -0800453 *ppos = p;
454 return read ? read : err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455}
456
457
Andrew Mortond7d4d842010-03-10 15:21:52 -0800458static ssize_t do_write_kmem(unsigned long p, const char __user *buf,
459 size_t count, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460{
461 ssize_t written, sz;
462 unsigned long copied;
463
464 written = 0;
465#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
466 /* we don't have page 0 mapped on sparc and m68k.. */
Wu Fengguangee323982009-12-14 17:58:10 -0800467 if (p < PAGE_SIZE) {
468 sz = size_inside_page(p, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 /* Hmm. Do something? */
470 buf += sz;
471 p += sz;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 count -= sz;
473 written += sz;
474 }
475#endif
476
477 while (count > 0) {
Thierry Reding4707a342014-07-28 17:20:33 +0200478 void *ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479
Wu Fengguangee323982009-12-14 17:58:10 -0800480 sz = size_inside_page(p, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481
482 /*
Andrew Mortond7d4d842010-03-10 15:21:52 -0800483 * On ia64 if a page has been mapped somewhere as uncached, then
484 * it must also be accessed uncached by the kernel or data
485 * corruption may occur.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 */
Thierry Reding4707a342014-07-28 17:20:33 +0200487 ptr = xlate_dev_kmem_ptr((void *)p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488
489 copied = copy_from_user(ptr, buf, sz);
490 if (copied) {
Jan Beulichc654d602006-03-25 03:07:31 -0800491 written += sz - copied;
492 if (written)
493 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 return -EFAULT;
495 }
496 buf += sz;
497 p += sz;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 count -= sz;
499 written += sz;
500 }
501
502 *ppos += written;
503 return written;
504}
505
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506/*
507 * This function writes to the *virtual* memory as seen by the kernel.
508 */
Andrew Mortond7d4d842010-03-10 15:21:52 -0800509static ssize_t write_kmem(struct file *file, const char __user *buf,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 size_t count, loff_t *ppos)
511{
512 unsigned long p = *ppos;
513 ssize_t wrote = 0;
514 ssize_t virtr = 0;
Hans Grob890537b2013-02-06 11:37:20 +0100515 char *kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */
KAMEZAWA Hiroyuki325fda72010-02-02 13:44:05 -0800516 int err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517
518 if (p < (unsigned long) high_memory) {
Wu Fengguang80ad89a2009-12-14 17:58:10 -0800519 unsigned long to_write = min_t(unsigned long, count,
520 (unsigned long)high_memory - p);
Wu Fengguangee323982009-12-14 17:58:10 -0800521 wrote = do_write_kmem(p, buf, to_write, ppos);
Wu Fengguang80ad89a2009-12-14 17:58:10 -0800522 if (wrote != to_write)
523 return wrote;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 p += wrote;
525 buf += wrote;
526 count -= wrote;
527 }
528
529 if (count > 0) {
530 kbuf = (char *)__get_free_page(GFP_KERNEL);
531 if (!kbuf)
532 return wrote ? wrote : -ENOMEM;
533 while (count > 0) {
Wu Fengguang80ad89a2009-12-14 17:58:10 -0800534 unsigned long sz = size_inside_page(p, count);
535 unsigned long n;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536
KAMEZAWA Hiroyuki325fda72010-02-02 13:44:05 -0800537 if (!is_vmalloc_or_module_addr((void *)p)) {
538 err = -ENXIO;
539 break;
540 }
Wu Fengguang80ad89a2009-12-14 17:58:10 -0800541 n = copy_from_user(kbuf, buf, sz);
542 if (n) {
KAMEZAWA Hiroyuki325fda72010-02-02 13:44:05 -0800543 err = -EFAULT;
544 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 }
Wu Fengguangc85e9a92010-02-02 13:44:06 -0800546 vwrite(kbuf, (char *)p, sz);
Wu Fengguang80ad89a2009-12-14 17:58:10 -0800547 count -= sz;
548 buf += sz;
549 virtr += sz;
550 p += sz;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 }
552 free_page((unsigned long)kbuf);
553 }
554
KAMEZAWA Hiroyuki325fda72010-02-02 13:44:05 -0800555 *ppos = p;
556 return virtr + wrote ? : err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557}
Arjan van de Venb781ecb2008-04-29 00:58:34 -0700558#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559
Russell King4f911d62007-05-08 00:28:17 -0700560#ifdef CONFIG_DEVPORT
Andrew Mortond7d4d842010-03-10 15:21:52 -0800561static ssize_t read_port(struct file *file, char __user *buf,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 size_t count, loff_t *ppos)
563{
564 unsigned long i = *ppos;
565 char __user *tmp = buf;
566
567 if (!access_ok(VERIFY_WRITE, buf, count))
Andrew Mortond7d4d842010-03-10 15:21:52 -0800568 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 while (count-- > 0 && i < 65536) {
Andrew Mortond7d4d842010-03-10 15:21:52 -0800570 if (__put_user(inb(i), tmp) < 0)
571 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 i++;
573 tmp++;
574 }
575 *ppos = i;
576 return tmp-buf;
577}
578
Andrew Mortond7d4d842010-03-10 15:21:52 -0800579static ssize_t write_port(struct file *file, const char __user *buf,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 size_t count, loff_t *ppos)
581{
582 unsigned long i = *ppos;
Hans Grob890537b2013-02-06 11:37:20 +0100583 const char __user *tmp = buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584
Andrew Mortond7d4d842010-03-10 15:21:52 -0800585 if (!access_ok(VERIFY_READ, buf, count))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 return -EFAULT;
587 while (count-- > 0 && i < 65536) {
588 char c;
Jan Beulichc654d602006-03-25 03:07:31 -0800589 if (__get_user(c, tmp)) {
590 if (tmp > buf)
591 break;
Andrew Mortond7d4d842010-03-10 15:21:52 -0800592 return -EFAULT;
Jan Beulichc654d602006-03-25 03:07:31 -0800593 }
Andrew Mortond7d4d842010-03-10 15:21:52 -0800594 outb(c, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 i++;
596 tmp++;
597 }
598 *ppos = i;
599 return tmp-buf;
600}
601#endif
602
Andrew Mortond7d4d842010-03-10 15:21:52 -0800603static ssize_t read_null(struct file *file, char __user *buf,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 size_t count, loff_t *ppos)
605{
606 return 0;
607}
608
Andrew Mortond7d4d842010-03-10 15:21:52 -0800609static ssize_t write_null(struct file *file, const char __user *buf,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 size_t count, loff_t *ppos)
611{
612 return count;
613}
614
Zach Brown162934d2013-05-07 16:18:27 -0700615static ssize_t aio_read_null(struct kiocb *iocb, const struct iovec *iov,
616 unsigned long nr_segs, loff_t pos)
617{
618 return 0;
619}
620
621static ssize_t aio_write_null(struct kiocb *iocb, const struct iovec *iov,
622 unsigned long nr_segs, loff_t pos)
623{
624 return iov_length(iov, nr_segs);
625}
626
Jens Axboe1ebd32f2006-04-26 14:40:08 +0200627static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf,
628 struct splice_desc *sd)
629{
630 return sd->len;
631}
632
Andrew Mortond7d4d842010-03-10 15:21:52 -0800633static ssize_t splice_write_null(struct pipe_inode_info *pipe, struct file *out,
Jens Axboe1ebd32f2006-04-26 14:40:08 +0200634 loff_t *ppos, size_t len, unsigned int flags)
635{
636 return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null);
637}
638
Al Viro13ba33e2014-08-18 10:04:12 -0400639static ssize_t read_iter_zero(struct kiocb *iocb, struct iov_iter *iter)
Zach Brown162934d2013-05-07 16:18:27 -0700640{
641 size_t written = 0;
Zach Brown162934d2013-05-07 16:18:27 -0700642
Al Viro13ba33e2014-08-18 10:04:12 -0400643 while (iov_iter_count(iter)) {
644 size_t chunk = iov_iter_count(iter), n;
645 if (chunk > PAGE_SIZE)
646 chunk = PAGE_SIZE; /* Just for latency reasons */
647 n = iov_iter_zero(chunk, iter);
648 if (!n && iov_iter_count(iter))
649 return written ? written : -EFAULT;
650 written += n;
651 if (signal_pending(current))
652 return written ? written : -ERESTARTSYS;
653 cond_resched();
Zach Brown162934d2013-05-07 16:18:27 -0700654 }
Al Viro13ba33e2014-08-18 10:04:12 -0400655 return written;
Zach Brown162934d2013-05-07 16:18:27 -0700656}
657
Andrew Mortond7d4d842010-03-10 15:21:52 -0800658static int mmap_zero(struct file *file, struct vm_area_struct *vma)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659{
Nick Piggin557ed1f2007-10-16 01:24:40 -0700660#ifndef CONFIG_MMU
661 return -ENOSYS;
662#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 if (vma->vm_flags & VM_SHARED)
664 return shmem_zero_setup(vma);
Nick Piggin557ed1f2007-10-16 01:24:40 -0700665 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667
Andrew Mortond7d4d842010-03-10 15:21:52 -0800668static ssize_t write_full(struct file *file, const char __user *buf,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 size_t count, loff_t *ppos)
670{
671 return -ENOSPC;
672}
673
674/*
675 * Special lseek() function for /dev/null and /dev/zero. Most notably, you
676 * can fopen() both devices with "a" now. This was previously impossible.
677 * -- SRB.
678 */
Andrew Mortond7d4d842010-03-10 15:21:52 -0800679static loff_t null_lseek(struct file *file, loff_t offset, int orig)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680{
681 return file->f_pos = 0;
682}
683
684/*
685 * The memory devices use the full 32/64 bits of the offset, and so we cannot
686 * check against negative addresses: they are ok. The return value is weird,
687 * though, in that case (0).
688 *
689 * also note that seeking relative to the "end of file" isn't supported:
690 * it has no meaning, so it returns -EINVAL.
691 */
Andrew Mortond7d4d842010-03-10 15:21:52 -0800692static loff_t memory_lseek(struct file *file, loff_t offset, int orig)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693{
694 loff_t ret;
695
Al Viro496ad9a2013-01-23 17:07:38 -0500696 mutex_lock(&file_inode(file)->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 switch (orig) {
Andrew Mortond7d4d842010-03-10 15:21:52 -0800698 case SEEK_CUR:
699 offset += file->f_pos;
Andrew Mortond7d4d842010-03-10 15:21:52 -0800700 case SEEK_SET:
701 /* to avoid userland mistaking f_pos=-9 as -EBADF=-9 */
Rasmus Villemoes71811f32013-06-05 17:09:39 +0000702 if (IS_ERR_VALUE((unsigned long long)offset)) {
Andrew Mortond7d4d842010-03-10 15:21:52 -0800703 ret = -EOVERFLOW;
704 break;
705 }
706 file->f_pos = offset;
707 ret = file->f_pos;
708 force_successful_syscall_return();
709 break;
710 default:
711 ret = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 }
Al Viro496ad9a2013-01-23 17:07:38 -0500713 mutex_unlock(&file_inode(file)->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 return ret;
715}
716
Hans Grob890537b2013-02-06 11:37:20 +0100717static int open_port(struct inode *inode, struct file *filp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718{
719 return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
720}
721
722#define zero_lseek null_lseek
723#define full_lseek null_lseek
724#define write_zero write_null
Zach Brown162934d2013-05-07 16:18:27 -0700725#define aio_write_zero aio_write_null
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726#define open_mem open_port
727#define open_kmem open_mem
728
Arjan van de Ven62322d22006-07-03 00:24:21 -0700729static const struct file_operations mem_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 .llseek = memory_lseek,
731 .read = read_mem,
732 .write = write_mem,
733 .mmap = mmap_mem,
734 .open = open_mem,
Christoph Hellwigb4caecd2015-01-14 10:42:32 +0100735#ifndef CONFIG_MMU
David Howells5da61852006-09-27 01:50:16 -0700736 .get_unmapped_area = get_unmapped_area_mem,
Christoph Hellwigb4caecd2015-01-14 10:42:32 +0100737 .mmap_capabilities = memory_mmap_capabilities,
738#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739};
740
Arjan van de Venb781ecb2008-04-29 00:58:34 -0700741#ifdef CONFIG_DEVKMEM
Arjan van de Ven62322d22006-07-03 00:24:21 -0700742static const struct file_operations kmem_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 .llseek = memory_lseek,
744 .read = read_kmem,
745 .write = write_kmem,
746 .mmap = mmap_kmem,
747 .open = open_kmem,
Christoph Hellwigb4caecd2015-01-14 10:42:32 +0100748#ifndef CONFIG_MMU
David Howells5da61852006-09-27 01:50:16 -0700749 .get_unmapped_area = get_unmapped_area_mem,
Christoph Hellwigb4caecd2015-01-14 10:42:32 +0100750 .mmap_capabilities = memory_mmap_capabilities,
751#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752};
Arjan van de Venb781ecb2008-04-29 00:58:34 -0700753#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754
Arjan van de Ven62322d22006-07-03 00:24:21 -0700755static const struct file_operations null_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 .llseek = null_lseek,
757 .read = read_null,
758 .write = write_null,
Zach Brown162934d2013-05-07 16:18:27 -0700759 .aio_read = aio_read_null,
760 .aio_write = aio_write_null,
Jens Axboe1ebd32f2006-04-26 14:40:08 +0200761 .splice_write = splice_write_null,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762};
763
Russell King4f911d62007-05-08 00:28:17 -0700764#ifdef CONFIG_DEVPORT
Arjan van de Ven62322d22006-07-03 00:24:21 -0700765static const struct file_operations port_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 .llseek = memory_lseek,
767 .read = read_port,
768 .write = write_port,
769 .open = open_port,
770};
771#endif
772
Arjan van de Ven62322d22006-07-03 00:24:21 -0700773static const struct file_operations zero_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 .llseek = zero_lseek,
Al Viro13ba33e2014-08-18 10:04:12 -0400775 .read = new_sync_read,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 .write = write_zero,
Al Viro13ba33e2014-08-18 10:04:12 -0400777 .read_iter = read_iter_zero,
Zach Brown162934d2013-05-07 16:18:27 -0700778 .aio_write = aio_write_zero,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 .mmap = mmap_zero,
Christoph Hellwigb4caecd2015-01-14 10:42:32 +0100780#ifndef CONFIG_MMU
781 .mmap_capabilities = zero_mmap_capabilities,
782#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783};
784
Arjan van de Ven62322d22006-07-03 00:24:21 -0700785static const struct file_operations full_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 .llseek = full_lseek,
Al Viro13ba33e2014-08-18 10:04:12 -0400787 .read = new_sync_read,
788 .read_iter = read_iter_zero,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 .write = write_full,
790};
791
Kay Sievers389e0cb2009-07-04 16:51:29 +0200792static const struct memdev {
793 const char *name;
Al Viro2c9ede52011-07-23 20:24:48 -0400794 umode_t mode;
Kay Sievers389e0cb2009-07-04 16:51:29 +0200795 const struct file_operations *fops;
Christoph Hellwigb4caecd2015-01-14 10:42:32 +0100796 fmode_t fmode;
Kay Sievers389e0cb2009-07-04 16:51:29 +0200797} devlist[] = {
Christoph Hellwigb4caecd2015-01-14 10:42:32 +0100798 [1] = { "mem", 0, &mem_fops, FMODE_UNSIGNED_OFFSET },
Adriano dos Santos Fernandesd6f47be2009-06-17 16:27:48 -0700799#ifdef CONFIG_DEVKMEM
Christoph Hellwigb4caecd2015-01-14 10:42:32 +0100800 [2] = { "kmem", 0, &kmem_fops, FMODE_UNSIGNED_OFFSET },
Adriano dos Santos Fernandesd6f47be2009-06-17 16:27:48 -0700801#endif
Christoph Hellwigb4caecd2015-01-14 10:42:32 +0100802 [3] = { "null", 0666, &null_fops, 0 },
Adriano dos Santos Fernandesd6f47be2009-06-17 16:27:48 -0700803#ifdef CONFIG_DEVPORT
Christoph Hellwigb4caecd2015-01-14 10:42:32 +0100804 [4] = { "port", 0, &port_fops, 0 },
Adriano dos Santos Fernandesd6f47be2009-06-17 16:27:48 -0700805#endif
Christoph Hellwigb4caecd2015-01-14 10:42:32 +0100806 [5] = { "zero", 0666, &zero_fops, 0 },
807 [7] = { "full", 0666, &full_fops, 0 },
808 [8] = { "random", 0666, &random_fops, 0 },
809 [9] = { "urandom", 0666, &urandom_fops, 0 },
Kay Sievers7f3a7812012-05-09 01:37:51 +0200810#ifdef CONFIG_PRINTK
Christoph Hellwigb4caecd2015-01-14 10:42:32 +0100811 [11] = { "kmsg", 0644, &kmsg_fops, 0 },
Kay Sievers7f3a7812012-05-09 01:37:51 +0200812#endif
Adriano dos Santos Fernandesd6f47be2009-06-17 16:27:48 -0700813};
814
815static int memory_open(struct inode *inode, struct file *filp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816{
Kay Sievers389e0cb2009-07-04 16:51:29 +0200817 int minor;
818 const struct memdev *dev;
Adriano dos Santos Fernandesd6f47be2009-06-17 16:27:48 -0700819
Kay Sievers389e0cb2009-07-04 16:51:29 +0200820 minor = iminor(inode);
821 if (minor >= ARRAY_SIZE(devlist))
Frederic Weisbecker205153a2009-10-09 20:31:02 +0200822 return -ENXIO;
Adriano dos Santos Fernandesd6f47be2009-06-17 16:27:48 -0700823
Kay Sievers389e0cb2009-07-04 16:51:29 +0200824 dev = &devlist[minor];
825 if (!dev->fops)
Frederic Weisbecker205153a2009-10-09 20:31:02 +0200826 return -ENXIO;
Adriano dos Santos Fernandesd6f47be2009-06-17 16:27:48 -0700827
Kay Sievers389e0cb2009-07-04 16:51:29 +0200828 filp->f_op = dev->fops;
Christoph Hellwigb4caecd2015-01-14 10:42:32 +0100829 filp->f_mode |= dev->fmode;
KAMEZAWA Hiroyuki4a3956c2010-10-01 14:20:22 -0700830
Kay Sievers389e0cb2009-07-04 16:51:29 +0200831 if (dev->fops->open)
Frederic Weisbecker205153a2009-10-09 20:31:02 +0200832 return dev->fops->open(inode, filp);
833
834 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835}
836
Arjan van de Ven62322d22006-07-03 00:24:21 -0700837static const struct file_operations memory_fops = {
Andrew Mortond7d4d842010-03-10 15:21:52 -0800838 .open = memory_open,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200839 .llseek = noop_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840};
841
Al Viro2c9ede52011-07-23 20:24:48 -0400842static char *mem_devnode(struct device *dev, umode_t *mode)
Kay Sieverse454cea2009-09-18 23:01:12 +0200843{
844 if (mode && devlist[MINOR(dev->devt)].mode)
845 *mode = devlist[MINOR(dev->devt)].mode;
846 return NULL;
847}
848
gregkh@suse.deca8eca62005-03-23 09:53:09 -0800849static struct class *mem_class;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850
851static int __init chr_dev_init(void)
852{
Kay Sievers389e0cb2009-07-04 16:51:29 +0200853 int minor;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854
Andrew Mortond7d4d842010-03-10 15:21:52 -0800855 if (register_chrdev(MEM_MAJOR, "mem", &memory_fops))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 printk("unable to get major %d for memory devs\n", MEM_MAJOR);
857
gregkh@suse.deca8eca62005-03-23 09:53:09 -0800858 mem_class = class_create(THIS_MODULE, "mem");
Anton Blanchard6e191f72010-04-06 14:34:55 -0700859 if (IS_ERR(mem_class))
860 return PTR_ERR(mem_class);
861
Kay Sieverse454cea2009-09-18 23:01:12 +0200862 mem_class->devnode = mem_devnode;
Kay Sievers389e0cb2009-07-04 16:51:29 +0200863 for (minor = 1; minor < ARRAY_SIZE(devlist); minor++) {
864 if (!devlist[minor].name)
865 continue;
Haren Mynenie1612de2012-07-11 15:18:44 +1000866
867 /*
Hans Grob890537b2013-02-06 11:37:20 +0100868 * Create /dev/port?
Haren Mynenie1612de2012-07-11 15:18:44 +1000869 */
870 if ((minor == DEVPORT_MINOR) && !arch_has_dev_port())
871 continue;
872
Kay Sievers389e0cb2009-07-04 16:51:29 +0200873 device_create(mem_class, NULL, MKDEV(MEM_MAJOR, minor),
874 NULL, devlist[minor].name);
875 }
Greg Kroah-Hartmanebf644c2006-07-25 17:13:31 -0700876
David Howells31d1d482010-08-06 16:34:43 +0100877 return tty_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878}
879
880fs_initcall(chr_dev_init);