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 }
87
88 if (cnt >= 2) {
89 unsigned short val;
90 pci_user_read_config_word(dev, pos, &val);
91 __put_user(cpu_to_le16(val), (__le16 __user *) buf);
92 buf += 2;
93 pos += 2;
94 cnt -= 2;
95 }
96
97 if (cnt) {
98 unsigned char val;
99 pci_user_read_config_byte(dev, pos, &val);
100 __put_user(val, buf);
101 buf++;
102 pos++;
103 cnt--;
104 }
105
106 pci_config_pm_runtime_put(dev);
107
108 *ppos = pos;
109 return nbytes;
110 }
111
proc_bus_pci_write(struct file * file,const char __user * buf,size_t nbytes,loff_t * ppos)112 static ssize_t proc_bus_pci_write(struct file *file, const char __user *buf,
113 size_t nbytes, loff_t *ppos)
114 {
115 struct inode *ino = file_inode(file);
116 struct pci_dev *dev = PDE_DATA(ino);
117 int pos = *ppos;
118 int size = dev->cfg_size;
119 int cnt, ret;
120
121 ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
122 if (ret)
123 return ret;
124
125 if (pos >= size)
126 return 0;
127 if (nbytes >= size)
128 nbytes = size;
129 if (pos + nbytes > size)
130 nbytes = size - pos;
131 cnt = nbytes;
132
133 if (!access_ok(buf, cnt))
134 return -EINVAL;
135
136 pci_config_pm_runtime_get(dev);
137
138 if ((pos & 1) && cnt) {
139 unsigned char val;
140 __get_user(val, buf);
141 pci_user_write_config_byte(dev, pos, val);
142 buf++;
143 pos++;
144 cnt--;
145 }
146
147 if ((pos & 3) && cnt > 2) {
148 __le16 val;
149 __get_user(val, (__le16 __user *) buf);
150 pci_user_write_config_word(dev, pos, le16_to_cpu(val));
151 buf += 2;
152 pos += 2;
153 cnt -= 2;
154 }
155
156 while (cnt >= 4) {
157 __le32 val;
158 __get_user(val, (__le32 __user *) buf);
159 pci_user_write_config_dword(dev, pos, le32_to_cpu(val));
160 buf += 4;
161 pos += 4;
162 cnt -= 4;
163 }
164
165 if (cnt >= 2) {
166 __le16 val;
167 __get_user(val, (__le16 __user *) buf);
168 pci_user_write_config_word(dev, pos, le16_to_cpu(val));
169 buf += 2;
170 pos += 2;
171 cnt -= 2;
172 }
173
174 if (cnt) {
175 unsigned char val;
176 __get_user(val, buf);
177 pci_user_write_config_byte(dev, pos, val);
178 buf++;
179 pos++;
180 cnt--;
181 }
182
183 pci_config_pm_runtime_put(dev);
184
185 *ppos = pos;
186 i_size_write(ino, dev->cfg_size);
187 return nbytes;
188 }
189
190 struct pci_filp_private {
191 enum pci_mmap_state mmap_state;
192 int write_combine;
193 };
194
proc_bus_pci_ioctl(struct file * file,unsigned int cmd,unsigned long arg)195 static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd,
196 unsigned long arg)
197 {
198 struct pci_dev *dev = PDE_DATA(file_inode(file));
199 #ifdef HAVE_PCI_MMAP
200 struct pci_filp_private *fpriv = file->private_data;
201 #endif /* HAVE_PCI_MMAP */
202 int ret = 0;
203
204 ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
205 if (ret)
206 return ret;
207
208 switch (cmd) {
209 case PCIIOC_CONTROLLER:
210 ret = pci_domain_nr(dev->bus);
211 break;
212
213 #ifdef HAVE_PCI_MMAP
214 case PCIIOC_MMAP_IS_IO:
215 if (!arch_can_pci_mmap_io())
216 return -EINVAL;
217 fpriv->mmap_state = pci_mmap_io;
218 break;
219
220 case PCIIOC_MMAP_IS_MEM:
221 fpriv->mmap_state = pci_mmap_mem;
222 break;
223
224 case PCIIOC_WRITE_COMBINE:
225 if (arch_can_pci_mmap_wc()) {
226 if (arg)
227 fpriv->write_combine = 1;
228 else
229 fpriv->write_combine = 0;
230 break;
231 }
232 /* If arch decided it can't, fall through... */
233 #endif /* HAVE_PCI_MMAP */
234 fallthrough;
235 default:
236 ret = -EINVAL;
237 break;
238 }
239
240 return ret;
241 }
242
243 #ifdef HAVE_PCI_MMAP
proc_bus_pci_mmap(struct file * file,struct vm_area_struct * vma)244 static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma)
245 {
246 struct pci_dev *dev = PDE_DATA(file_inode(file));
247 struct pci_filp_private *fpriv = file->private_data;
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 ret = pci_mmap_page_range(dev, i, vma,
278 fpriv->mmap_state, write_combine);
279 if (ret < 0)
280 return ret;
281
282 return 0;
283 }
284
proc_bus_pci_open(struct inode * inode,struct file * file)285 static int proc_bus_pci_open(struct inode *inode, struct file *file)
286 {
287 struct pci_filp_private *fpriv = kmalloc(sizeof(*fpriv), GFP_KERNEL);
288
289 if (!fpriv)
290 return -ENOMEM;
291
292 fpriv->mmap_state = pci_mmap_io;
293 fpriv->write_combine = 0;
294
295 file->private_data = fpriv;
296
297 return 0;
298 }
299
proc_bus_pci_release(struct inode * inode,struct file * file)300 static int proc_bus_pci_release(struct inode *inode, struct file *file)
301 {
302 kfree(file->private_data);
303 file->private_data = NULL;
304
305 return 0;
306 }
307 #endif /* HAVE_PCI_MMAP */
308
309 static const struct proc_ops proc_bus_pci_ops = {
310 .proc_lseek = proc_bus_pci_lseek,
311 .proc_read = proc_bus_pci_read,
312 .proc_write = proc_bus_pci_write,
313 .proc_ioctl = proc_bus_pci_ioctl,
314 #ifdef CONFIG_COMPAT
315 .proc_compat_ioctl = proc_bus_pci_ioctl,
316 #endif
317 #ifdef HAVE_PCI_MMAP
318 .proc_open = proc_bus_pci_open,
319 .proc_release = proc_bus_pci_release,
320 .proc_mmap = proc_bus_pci_mmap,
321 #ifdef HAVE_ARCH_PCI_GET_UNMAPPED_AREA
322 .proc_get_unmapped_area = get_pci_unmapped_area,
323 #endif /* HAVE_ARCH_PCI_GET_UNMAPPED_AREA */
324 #endif /* HAVE_PCI_MMAP */
325 };
326
327 /* iterator */
pci_seq_start(struct seq_file * m,loff_t * pos)328 static void *pci_seq_start(struct seq_file *m, loff_t *pos)
329 {
330 struct pci_dev *dev = NULL;
331 loff_t n = *pos;
332
333 for_each_pci_dev(dev) {
334 if (!n--)
335 break;
336 }
337 return dev;
338 }
339
pci_seq_next(struct seq_file * m,void * v,loff_t * pos)340 static void *pci_seq_next(struct seq_file *m, void *v, loff_t *pos)
341 {
342 struct pci_dev *dev = v;
343
344 (*pos)++;
345 dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
346 return dev;
347 }
348
pci_seq_stop(struct seq_file * m,void * v)349 static void pci_seq_stop(struct seq_file *m, void *v)
350 {
351 if (v) {
352 struct pci_dev *dev = v;
353 pci_dev_put(dev);
354 }
355 }
356
show_device(struct seq_file * m,void * v)357 static int show_device(struct seq_file *m, void *v)
358 {
359 const struct pci_dev *dev = v;
360 const struct pci_driver *drv;
361 int i;
362
363 if (dev == NULL)
364 return 0;
365
366 drv = pci_dev_driver(dev);
367 seq_printf(m, "%02x%02x\t%04x%04x\t%x",
368 dev->bus->number,
369 dev->devfn,
370 dev->vendor,
371 dev->device,
372 dev->irq);
373
374 /* only print standard and ROM resources to preserve compatibility */
375 for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
376 resource_size_t start, end;
377 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
378 seq_printf(m, "\t%16llx",
379 (unsigned long long)(start |
380 (dev->resource[i].flags & PCI_REGION_FLAG_MASK)));
381 }
382 for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
383 resource_size_t start, end;
384 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
385 seq_printf(m, "\t%16llx",
386 dev->resource[i].start < dev->resource[i].end ?
387 (unsigned long long)(end - start) + 1 : 0);
388 }
389 seq_putc(m, '\t');
390 if (drv)
391 seq_puts(m, drv->name);
392 seq_putc(m, '\n');
393 return 0;
394 }
395
396 static const struct seq_operations proc_bus_pci_devices_op = {
397 .start = pci_seq_start,
398 .next = pci_seq_next,
399 .stop = pci_seq_stop,
400 .show = show_device
401 };
402
403 static struct proc_dir_entry *proc_bus_pci_dir;
404
pci_proc_attach_device(struct pci_dev * dev)405 int pci_proc_attach_device(struct pci_dev *dev)
406 {
407 struct pci_bus *bus = dev->bus;
408 struct proc_dir_entry *e;
409 char name[16];
410
411 if (!proc_initialized)
412 return -EACCES;
413
414 if (!bus->procdir) {
415 if (pci_proc_domain(bus)) {
416 sprintf(name, "%04x:%02x", pci_domain_nr(bus),
417 bus->number);
418 } else {
419 sprintf(name, "%02x", bus->number);
420 }
421 bus->procdir = proc_mkdir(name, proc_bus_pci_dir);
422 if (!bus->procdir)
423 return -ENOMEM;
424 }
425
426 sprintf(name, "%02x.%x", PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn));
427 e = proc_create_data(name, S_IFREG | S_IRUGO | S_IWUSR, bus->procdir,
428 &proc_bus_pci_ops, dev);
429 if (!e)
430 return -ENOMEM;
431 proc_set_size(e, dev->cfg_size);
432 dev->procent = e;
433
434 return 0;
435 }
436
pci_proc_detach_device(struct pci_dev * dev)437 int pci_proc_detach_device(struct pci_dev *dev)
438 {
439 proc_remove(dev->procent);
440 dev->procent = NULL;
441 return 0;
442 }
443
pci_proc_detach_bus(struct pci_bus * bus)444 int pci_proc_detach_bus(struct pci_bus *bus)
445 {
446 proc_remove(bus->procdir);
447 return 0;
448 }
449
pci_proc_init(void)450 static int __init pci_proc_init(void)
451 {
452 struct pci_dev *dev = NULL;
453 proc_bus_pci_dir = proc_mkdir("bus/pci", NULL);
454 proc_create_seq("devices", 0, proc_bus_pci_dir,
455 &proc_bus_pci_devices_op);
456 proc_initialized = 1;
457 for_each_pci_dev(dev)
458 pci_proc_attach_device(dev);
459
460 return 0;
461 }
462 device_initcall(pci_proc_init);
463