1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Procfs interface for the PCI bus
4 *
5 * Copyright (c) 1997--1999 Martin Mares <mj@ucw.cz>
6 */
7
8 #include <linux/init.h>
9 #include <linux/pci.h>
10 #include <linux/slab.h>
11 #include <linux/module.h>
12 #include <linux/proc_fs.h>
13 #include <linux/seq_file.h>
14 #include <linux/capability.h>
15 #include <linux/uaccess.h>
16 #include <linux/security.h>
17 #include <asm/byteorder.h>
18 #include "pci.h"
19
20 static int proc_initialized; /* = 0 */
21
proc_bus_pci_lseek(struct file * file,loff_t off,int whence)22 static loff_t proc_bus_pci_lseek(struct file *file, loff_t off, int whence)
23 {
24 struct pci_dev *dev = pde_data(file_inode(file));
25 return fixed_size_llseek(file, off, whence, dev->cfg_size);
26 }
27
proc_bus_pci_read(struct file * file,char __user * buf,size_t nbytes,loff_t * ppos)28 static ssize_t proc_bus_pci_read(struct file *file, char __user *buf,
29 size_t nbytes, loff_t *ppos)
30 {
31 struct pci_dev *dev = pde_data(file_inode(file));
32 unsigned int pos = *ppos;
33 unsigned int cnt, size;
34
35 /*
36 * Normal users can read only the standardized portion of the
37 * configuration space as several chips lock up when trying to read
38 * undefined locations (think of Intel PIIX4 as a typical example).
39 */
40
41 if (capable(CAP_SYS_ADMIN))
42 size = dev->cfg_size;
43 else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
44 size = 128;
45 else
46 size = 64;
47
48 if (pos >= size)
49 return 0;
50 if (nbytes >= size)
51 nbytes = size;
52 if (pos + nbytes > size)
53 nbytes = size - pos;
54 cnt = nbytes;
55
56 if (!access_ok(buf, cnt))
57 return -EINVAL;
58
59 pci_config_pm_runtime_get(dev);
60
61 if ((pos & 1) && cnt) {
62 unsigned char val;
63 pci_user_read_config_byte(dev, pos, &val);
64 __put_user(val, buf);
65 buf++;
66 pos++;
67 cnt--;
68 }
69
70 if ((pos & 3) && cnt > 2) {
71 unsigned short val;
72 pci_user_read_config_word(dev, pos, &val);
73 __put_user(cpu_to_le16(val), (__le16 __user *) buf);
74 buf += 2;
75 pos += 2;
76 cnt -= 2;
77 }
78
79 while (cnt >= 4) {
80 unsigned int val;
81 pci_user_read_config_dword(dev, pos, &val);
82 __put_user(cpu_to_le32(val), (__le32 __user *) buf);
83 buf += 4;
84 pos += 4;
85 cnt -= 4;
86 cond_resched();
87 }
88
89 if (cnt >= 2) {
90 unsigned short val;
91 pci_user_read_config_word(dev, pos, &val);
92 __put_user(cpu_to_le16(val), (__le16 __user *) buf);
93 buf += 2;
94 pos += 2;
95 cnt -= 2;
96 }
97
98 if (cnt) {
99 unsigned char val;
100 pci_user_read_config_byte(dev, pos, &val);
101 __put_user(val, buf);
102 pos++;
103 }
104
105 pci_config_pm_runtime_put(dev);
106
107 *ppos = pos;
108 return nbytes;
109 }
110
proc_bus_pci_write(struct file * file,const char __user * buf,size_t nbytes,loff_t * ppos)111 static ssize_t proc_bus_pci_write(struct file *file, const char __user *buf,
112 size_t nbytes, loff_t *ppos)
113 {
114 struct inode *ino = file_inode(file);
115 struct pci_dev *dev = pde_data(ino);
116 int pos = *ppos;
117 int size = dev->cfg_size;
118 int cnt, ret;
119
120 ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
121 if (ret)
122 return ret;
123
124 if (pos >= size)
125 return 0;
126 if (nbytes >= size)
127 nbytes = size;
128 if (pos + nbytes > size)
129 nbytes = size - pos;
130 cnt = nbytes;
131
132 if (!access_ok(buf, cnt))
133 return -EINVAL;
134
135 pci_config_pm_runtime_get(dev);
136
137 if ((pos & 1) && cnt) {
138 unsigned char val;
139 __get_user(val, buf);
140 pci_user_write_config_byte(dev, pos, val);
141 buf++;
142 pos++;
143 cnt--;
144 }
145
146 if ((pos & 3) && cnt > 2) {
147 __le16 val;
148 __get_user(val, (__le16 __user *) buf);
149 pci_user_write_config_word(dev, pos, le16_to_cpu(val));
150 buf += 2;
151 pos += 2;
152 cnt -= 2;
153 }
154
155 while (cnt >= 4) {
156 __le32 val;
157 __get_user(val, (__le32 __user *) buf);
158 pci_user_write_config_dword(dev, pos, le32_to_cpu(val));
159 buf += 4;
160 pos += 4;
161 cnt -= 4;
162 }
163
164 if (cnt >= 2) {
165 __le16 val;
166 __get_user(val, (__le16 __user *) buf);
167 pci_user_write_config_word(dev, pos, le16_to_cpu(val));
168 buf += 2;
169 pos += 2;
170 cnt -= 2;
171 }
172
173 if (cnt) {
174 unsigned char val;
175 __get_user(val, buf);
176 pci_user_write_config_byte(dev, pos, val);
177 pos++;
178 }
179
180 pci_config_pm_runtime_put(dev);
181
182 *ppos = pos;
183 i_size_write(ino, dev->cfg_size);
184 return nbytes;
185 }
186
187 #ifdef HAVE_PCI_MMAP
188 struct pci_filp_private {
189 enum pci_mmap_state mmap_state;
190 int write_combine;
191 };
192 #endif /* HAVE_PCI_MMAP */
193
proc_bus_pci_ioctl(struct file * file,unsigned int cmd,unsigned long arg)194 static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd,
195 unsigned long arg)
196 {
197 struct pci_dev *dev = pde_data(file_inode(file));
198 #ifdef HAVE_PCI_MMAP
199 struct pci_filp_private *fpriv = file->private_data;
200 #endif /* HAVE_PCI_MMAP */
201 int ret = 0;
202
203 ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
204 if (ret)
205 return ret;
206
207 switch (cmd) {
208 case PCIIOC_CONTROLLER:
209 ret = pci_domain_nr(dev->bus);
210 break;
211
212 #ifdef HAVE_PCI_MMAP
213 case PCIIOC_MMAP_IS_IO:
214 if (!arch_can_pci_mmap_io())
215 return -EINVAL;
216 fpriv->mmap_state = pci_mmap_io;
217 break;
218
219 case PCIIOC_MMAP_IS_MEM:
220 fpriv->mmap_state = pci_mmap_mem;
221 break;
222
223 case PCIIOC_WRITE_COMBINE:
224 if (arch_can_pci_mmap_wc()) {
225 if (arg)
226 fpriv->write_combine = 1;
227 else
228 fpriv->write_combine = 0;
229 break;
230 }
231 /* If arch decided it can't, fall through... */
232 fallthrough;
233 #endif /* HAVE_PCI_MMAP */
234 default:
235 ret = -EINVAL;
236 break;
237 }
238
239 return ret;
240 }
241
242 #ifdef HAVE_PCI_MMAP
proc_bus_pci_mmap(struct file * file,struct vm_area_struct * vma)243 static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma)
244 {
245 struct pci_dev *dev = pde_data(file_inode(file));
246 struct pci_filp_private *fpriv = file->private_data;
247 resource_size_t start, end;
248 int i, ret, write_combine = 0, res_bit = IORESOURCE_MEM;
249
250 if (!capable(CAP_SYS_RAWIO) ||
251 security_locked_down(LOCKDOWN_PCI_ACCESS))
252 return -EPERM;
253
254 if (fpriv->mmap_state == pci_mmap_io) {
255 if (!arch_can_pci_mmap_io())
256 return -EINVAL;
257 res_bit = IORESOURCE_IO;
258 }
259
260 /* Make sure the caller is mapping a real resource for this device */
261 for (i = 0; i < PCI_STD_NUM_BARS; i++) {
262 if (dev->resource[i].flags & res_bit &&
263 pci_mmap_fits(dev, i, vma, PCI_MMAP_PROCFS))
264 break;
265 }
266
267 if (i >= PCI_STD_NUM_BARS)
268 return -ENODEV;
269
270 if (fpriv->mmap_state == pci_mmap_mem &&
271 fpriv->write_combine) {
272 if (dev->resource[i].flags & IORESOURCE_PREFETCH)
273 write_combine = 1;
274 else
275 return -EINVAL;
276 }
277
278 if (dev->resource[i].flags & IORESOURCE_MEM &&
279 iomem_is_exclusive(dev->resource[i].start))
280 return -EINVAL;
281
282 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
283
284 /* Adjust vm_pgoff to be the offset within the resource */
285 vma->vm_pgoff -= start >> PAGE_SHIFT;
286 ret = pci_mmap_resource_range(dev, i, vma,
287 fpriv->mmap_state, write_combine);
288 if (ret < 0)
289 return ret;
290
291 return 0;
292 }
293
proc_bus_pci_open(struct inode * inode,struct file * file)294 static int proc_bus_pci_open(struct inode *inode, struct file *file)
295 {
296 struct pci_filp_private *fpriv = kmalloc(sizeof(*fpriv), GFP_KERNEL);
297
298 if (!fpriv)
299 return -ENOMEM;
300
301 fpriv->mmap_state = pci_mmap_io;
302 fpriv->write_combine = 0;
303
304 file->private_data = fpriv;
305 file->f_mapping = iomem_get_mapping();
306
307 return 0;
308 }
309
proc_bus_pci_release(struct inode * inode,struct file * file)310 static int proc_bus_pci_release(struct inode *inode, struct file *file)
311 {
312 kfree(file->private_data);
313 file->private_data = NULL;
314
315 return 0;
316 }
317 #endif /* HAVE_PCI_MMAP */
318
319 static const struct proc_ops proc_bus_pci_ops = {
320 .proc_lseek = proc_bus_pci_lseek,
321 .proc_read = proc_bus_pci_read,
322 .proc_write = proc_bus_pci_write,
323 .proc_ioctl = proc_bus_pci_ioctl,
324 #ifdef CONFIG_COMPAT
325 .proc_compat_ioctl = proc_bus_pci_ioctl,
326 #endif
327 #ifdef HAVE_PCI_MMAP
328 .proc_open = proc_bus_pci_open,
329 .proc_release = proc_bus_pci_release,
330 .proc_mmap = proc_bus_pci_mmap,
331 #ifdef HAVE_ARCH_PCI_GET_UNMAPPED_AREA
332 .proc_get_unmapped_area = get_pci_unmapped_area,
333 #endif /* HAVE_ARCH_PCI_GET_UNMAPPED_AREA */
334 #endif /* HAVE_PCI_MMAP */
335 };
336
337 /* iterator */
pci_seq_start(struct seq_file * m,loff_t * pos)338 static void *pci_seq_start(struct seq_file *m, loff_t *pos)
339 {
340 struct pci_dev *dev = NULL;
341 loff_t n = *pos;
342
343 for_each_pci_dev(dev) {
344 if (!n--)
345 break;
346 }
347 return dev;
348 }
349
pci_seq_next(struct seq_file * m,void * v,loff_t * pos)350 static void *pci_seq_next(struct seq_file *m, void *v, loff_t *pos)
351 {
352 struct pci_dev *dev = v;
353
354 (*pos)++;
355 dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
356 return dev;
357 }
358
pci_seq_stop(struct seq_file * m,void * v)359 static void pci_seq_stop(struct seq_file *m, void *v)
360 {
361 if (v) {
362 struct pci_dev *dev = v;
363 pci_dev_put(dev);
364 }
365 }
366
show_device(struct seq_file * m,void * v)367 static int show_device(struct seq_file *m, void *v)
368 {
369 const struct pci_dev *dev = v;
370 const struct pci_driver *drv;
371 int i;
372
373 if (dev == NULL)
374 return 0;
375
376 drv = pci_dev_driver(dev);
377 seq_printf(m, "%02x%02x\t%04x%04x\t%x",
378 dev->bus->number,
379 dev->devfn,
380 dev->vendor,
381 dev->device,
382 dev->irq);
383
384 /* only print standard and ROM resources to preserve compatibility */
385 for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
386 resource_size_t start, end;
387 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
388 seq_printf(m, "\t%16llx",
389 (unsigned long long)(start |
390 (dev->resource[i].flags & PCI_REGION_FLAG_MASK)));
391 }
392 for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
393 resource_size_t start, end;
394 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
395 seq_printf(m, "\t%16llx",
396 dev->resource[i].start < dev->resource[i].end ?
397 (unsigned long long)(end - start) + 1 : 0);
398 }
399 seq_putc(m, '\t');
400 if (drv)
401 seq_puts(m, drv->name);
402 seq_putc(m, '\n');
403 return 0;
404 }
405
406 static const struct seq_operations proc_bus_pci_devices_op = {
407 .start = pci_seq_start,
408 .next = pci_seq_next,
409 .stop = pci_seq_stop,
410 .show = show_device
411 };
412
413 static struct proc_dir_entry *proc_bus_pci_dir;
414
pci_proc_attach_device(struct pci_dev * dev)415 int pci_proc_attach_device(struct pci_dev *dev)
416 {
417 struct pci_bus *bus = dev->bus;
418 struct proc_dir_entry *e;
419 char name[16];
420
421 if (!proc_initialized)
422 return -EACCES;
423
424 if (!bus->procdir) {
425 if (pci_proc_domain(bus)) {
426 sprintf(name, "%04x:%02x", pci_domain_nr(bus),
427 bus->number);
428 } else {
429 sprintf(name, "%02x", bus->number);
430 }
431 bus->procdir = proc_mkdir(name, proc_bus_pci_dir);
432 if (!bus->procdir)
433 return -ENOMEM;
434 }
435
436 sprintf(name, "%02x.%x", PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn));
437 e = proc_create_data(name, S_IFREG | S_IRUGO | S_IWUSR, bus->procdir,
438 &proc_bus_pci_ops, dev);
439 if (!e)
440 return -ENOMEM;
441 proc_set_size(e, dev->cfg_size);
442 dev->procent = e;
443
444 return 0;
445 }
446
pci_proc_detach_device(struct pci_dev * dev)447 int pci_proc_detach_device(struct pci_dev *dev)
448 {
449 proc_remove(dev->procent);
450 dev->procent = NULL;
451 return 0;
452 }
453
pci_proc_detach_bus(struct pci_bus * bus)454 int pci_proc_detach_bus(struct pci_bus *bus)
455 {
456 proc_remove(bus->procdir);
457 return 0;
458 }
459
pci_proc_init(void)460 static int __init pci_proc_init(void)
461 {
462 struct pci_dev *dev = NULL;
463 proc_bus_pci_dir = proc_mkdir("bus/pci", NULL);
464 proc_create_seq("devices", 0, proc_bus_pci_dir,
465 &proc_bus_pci_devices_op);
466 proc_initialized = 1;
467 for_each_pci_dev(dev)
468 pci_proc_attach_device(dev);
469
470 return 0;
471 }
472 device_initcall(pci_proc_init);
473