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1/*
2 * Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 */
14#include <linux/debugfs.h>
15#include <linux/dma-mapping.h>
16#include <linux/uaccess.h>
17
18#include <soc/tegra/bpmp.h>
19#include <soc/tegra/bpmp-abi.h>
20
21struct seqbuf {
22 char *buf;
23 size_t pos;
24 size_t size;
25};
26
27static void seqbuf_init(struct seqbuf *seqbuf, void *buf, size_t size)
28{
29 seqbuf->buf = buf;
30 seqbuf->size = size;
31 seqbuf->pos = 0;
32}
33
34static size_t seqbuf_avail(struct seqbuf *seqbuf)
35{
36 return seqbuf->pos < seqbuf->size ? seqbuf->size - seqbuf->pos : 0;
37}
38
39static size_t seqbuf_status(struct seqbuf *seqbuf)
40{
41 return seqbuf->pos <= seqbuf->size ? 0 : -EOVERFLOW;
42}
43
44static int seqbuf_eof(struct seqbuf *seqbuf)
45{
46 return seqbuf->pos >= seqbuf->size;
47}
48
49static int seqbuf_read(struct seqbuf *seqbuf, void *buf, size_t nbyte)
50{
51 nbyte = min(nbyte, seqbuf_avail(seqbuf));
52 memcpy(buf, seqbuf->buf + seqbuf->pos, nbyte);
53 seqbuf->pos += nbyte;
54 return seqbuf_status(seqbuf);
55}
56
57static int seqbuf_read_u32(struct seqbuf *seqbuf, uint32_t *v)
58{
59 int err;
60
61 err = seqbuf_read(seqbuf, v, 4);
62 *v = le32_to_cpu(*v);
63 return err;
64}
65
66static int seqbuf_read_str(struct seqbuf *seqbuf, const char **str)
67{
68 *str = seqbuf->buf + seqbuf->pos;
69 seqbuf->pos += strnlen(*str, seqbuf_avail(seqbuf));
70 seqbuf->pos++;
71 return seqbuf_status(seqbuf);
72}
73
74static void seqbuf_seek(struct seqbuf *seqbuf, ssize_t offset)
75{
76 seqbuf->pos += offset;
77}
78
79/* map filename in Linux debugfs to corresponding entry in BPMP */
80static const char *get_filename(struct tegra_bpmp *bpmp,
81 const struct file *file, char *buf, int size)
82{
83 char root_path_buf[512];
84 const char *root_path;
85 const char *filename;
86 size_t root_len;
87
88 root_path = dentry_path(bpmp->debugfs_mirror, root_path_buf,
89 sizeof(root_path_buf));
90 if (IS_ERR(root_path))
91 return NULL;
92
93 root_len = strlen(root_path);
94
95 filename = dentry_path(file->f_path.dentry, buf, size);
96 if (IS_ERR(filename))
97 return NULL;
98
99 if (strlen(filename) < root_len ||
100 strncmp(filename, root_path, root_len))
101 return NULL;
102
103 filename += root_len;
104
105 return filename;
106}
107
108static int mrq_debugfs_read(struct tegra_bpmp *bpmp,
109 dma_addr_t name, size_t sz_name,
110 dma_addr_t data, size_t sz_data,
111 size_t *nbytes)
112{
113 struct mrq_debugfs_request req = {
114 .cmd = cpu_to_le32(CMD_DEBUGFS_READ),
115 .fop = {
116 .fnameaddr = cpu_to_le32((uint32_t)name),
117 .fnamelen = cpu_to_le32((uint32_t)sz_name),
118 .dataaddr = cpu_to_le32((uint32_t)data),
119 .datalen = cpu_to_le32((uint32_t)sz_data),
120 },
121 };
122 struct mrq_debugfs_response resp;
123 struct tegra_bpmp_message msg = {
124 .mrq = MRQ_DEBUGFS,
125 .tx = {
126 .data = &req,
127 .size = sizeof(req),
128 },
129 .rx = {
130 .data = &resp,
131 .size = sizeof(resp),
132 },
133 };
134 int err;
135
136 err = tegra_bpmp_transfer(bpmp, &msg);
137 if (err < 0)
138 return err;
139
140 *nbytes = (size_t)resp.fop.nbytes;
141
142 return 0;
143}
144
145static int mrq_debugfs_write(struct tegra_bpmp *bpmp,
146 dma_addr_t name, size_t sz_name,
147 dma_addr_t data, size_t sz_data)
148{
149 const struct mrq_debugfs_request req = {
150 .cmd = cpu_to_le32(CMD_DEBUGFS_WRITE),
151 .fop = {
152 .fnameaddr = cpu_to_le32((uint32_t)name),
153 .fnamelen = cpu_to_le32((uint32_t)sz_name),
154 .dataaddr = cpu_to_le32((uint32_t)data),
155 .datalen = cpu_to_le32((uint32_t)sz_data),
156 },
157 };
158 struct tegra_bpmp_message msg = {
159 .mrq = MRQ_DEBUGFS,
160 .tx = {
161 .data = &req,
162 .size = sizeof(req),
163 },
164 };
165
166 return tegra_bpmp_transfer(bpmp, &msg);
167}
168
169static int mrq_debugfs_dumpdir(struct tegra_bpmp *bpmp, dma_addr_t addr,
170 size_t size, size_t *nbytes)
171{
172 const struct mrq_debugfs_request req = {
173 .cmd = cpu_to_le32(CMD_DEBUGFS_DUMPDIR),
174 .dumpdir = {
175 .dataaddr = cpu_to_le32((uint32_t)addr),
176 .datalen = cpu_to_le32((uint32_t)size),
177 },
178 };
179 struct mrq_debugfs_response resp;
180 struct tegra_bpmp_message msg = {
181 .mrq = MRQ_DEBUGFS,
182 .tx = {
183 .data = &req,
184 .size = sizeof(req),
185 },
186 .rx = {
187 .data = &resp,
188 .size = sizeof(resp),
189 },
190 };
191 int err;
192
193 err = tegra_bpmp_transfer(bpmp, &msg);
194 if (err < 0)
195 return err;
196
197 *nbytes = (size_t)resp.dumpdir.nbytes;
198
199 return 0;
200}
201
202static int debugfs_show(struct seq_file *m, void *p)
203{
204 struct file *file = m->private;
205 struct inode *inode = file_inode(file);
206 struct tegra_bpmp *bpmp = inode->i_private;
207 const size_t datasize = m->size;
208 const size_t namesize = SZ_256;
209 void *datavirt, *namevirt;
210 dma_addr_t dataphys, namephys;
211 char buf[256];
212 const char *filename;
213 size_t len, nbytes;
214 int ret;
215
216 filename = get_filename(bpmp, file, buf, sizeof(buf));
217 if (!filename)
218 return -ENOENT;
219
220 namevirt = dma_alloc_coherent(bpmp->dev, namesize, &namephys,
221 GFP_KERNEL | GFP_DMA32);
222 if (!namevirt)
223 return -ENOMEM;
224
225 datavirt = dma_alloc_coherent(bpmp->dev, datasize, &dataphys,
226 GFP_KERNEL | GFP_DMA32);
227 if (!datavirt) {
228 ret = -ENOMEM;
229 goto free_namebuf;
230 }
231
232 len = strlen(filename);
233 strncpy(namevirt, filename, namesize);
234
235 ret = mrq_debugfs_read(bpmp, namephys, len, dataphys, datasize,
236 &nbytes);
237
238 if (!ret)
239 seq_write(m, datavirt, nbytes);
240
241 dma_free_coherent(bpmp->dev, datasize, datavirt, dataphys);
242free_namebuf:
243 dma_free_coherent(bpmp->dev, namesize, namevirt, namephys);
244
245 return ret;
246}
247
248static int debugfs_open(struct inode *inode, struct file *file)
249{
250 return single_open_size(file, debugfs_show, file, SZ_128K);
251}
252
253static ssize_t debugfs_store(struct file *file, const char __user *buf,
254 size_t count, loff_t *f_pos)
255{
256 struct inode *inode = file_inode(file);
257 struct tegra_bpmp *bpmp = inode->i_private;
258 const size_t datasize = count;
259 const size_t namesize = SZ_256;
260 void *datavirt, *namevirt;
261 dma_addr_t dataphys, namephys;
262 char fnamebuf[256];
263 const char *filename;
264 size_t len;
265 int ret;
266
267 filename = get_filename(bpmp, file, fnamebuf, sizeof(fnamebuf));
268 if (!filename)
269 return -ENOENT;
270
271 namevirt = dma_alloc_coherent(bpmp->dev, namesize, &namephys,
272 GFP_KERNEL | GFP_DMA32);
273 if (!namevirt)
274 return -ENOMEM;
275
276 datavirt = dma_alloc_coherent(bpmp->dev, datasize, &dataphys,
277 GFP_KERNEL | GFP_DMA32);
278 if (!datavirt) {
279 ret = -ENOMEM;
280 goto free_namebuf;
281 }
282
283 len = strlen(filename);
284 strncpy(namevirt, filename, namesize);
285
286 if (copy_from_user(datavirt, buf, count)) {
287 ret = -EFAULT;
288 goto free_databuf;
289 }
290
291 ret = mrq_debugfs_write(bpmp, namephys, len, dataphys,
292 count);
293
294free_databuf:
295 dma_free_coherent(bpmp->dev, datasize, datavirt, dataphys);
296free_namebuf:
297 dma_free_coherent(bpmp->dev, namesize, namevirt, namephys);
298
299 return ret ?: count;
300}
301
302static const struct file_operations debugfs_fops = {
303 .open = debugfs_open,
304 .read = seq_read,
305 .llseek = seq_lseek,
306 .write = debugfs_store,
307 .release = single_release,
308};
309
310static int bpmp_populate_dir(struct tegra_bpmp *bpmp, struct seqbuf *seqbuf,
311 struct dentry *parent, uint32_t depth)
312{
313 int err;
314 uint32_t d, t;
315 const char *name;
316 struct dentry *dentry;
317
318 while (!seqbuf_eof(seqbuf)) {
319 err = seqbuf_read_u32(seqbuf, &d);
320 if (err < 0)
321 return err;
322
323 if (d < depth) {
324 seqbuf_seek(seqbuf, -4);
325 /* go up a level */
326 return 0;
327 } else if (d != depth) {
328 /* malformed data received from BPMP */
329 return -EIO;
330 }
331
332 err = seqbuf_read_u32(seqbuf, &t);
333 if (err < 0)
334 return err;
335 err = seqbuf_read_str(seqbuf, &name);
336 if (err < 0)
337 return err;
338
339 if (t & DEBUGFS_S_ISDIR) {
340 dentry = debugfs_create_dir(name, parent);
341 if (!dentry)
342 return -ENOMEM;
343 err = bpmp_populate_dir(bpmp, seqbuf, dentry, depth+1);
344 if (err < 0)
345 return err;
346 } else {
347 umode_t mode;
348
349 mode = t & DEBUGFS_S_IRUSR ? S_IRUSR : 0;
350 mode |= t & DEBUGFS_S_IWUSR ? S_IWUSR : 0;
351 dentry = debugfs_create_file(name, mode,
352 parent, bpmp,
353 &debugfs_fops);
354 if (!dentry)
355 return -ENOMEM;
356 }
357 }
358
359 return 0;
360}
361
362static int create_debugfs_mirror(struct tegra_bpmp *bpmp, void *buf,
363 size_t bufsize, struct dentry *root)
364{
365 struct seqbuf seqbuf;
366 int err;
367
368 bpmp->debugfs_mirror = debugfs_create_dir("debug", root);
369 if (!bpmp->debugfs_mirror)
370 return -ENOMEM;
371
372 seqbuf_init(&seqbuf, buf, bufsize);
373 err = bpmp_populate_dir(bpmp, &seqbuf, bpmp->debugfs_mirror, 0);
374 if (err < 0) {
375 debugfs_remove_recursive(bpmp->debugfs_mirror);
376 bpmp->debugfs_mirror = NULL;
377 }
378
379 return err;
380}
381
382static int mrq_is_supported(struct tegra_bpmp *bpmp, unsigned int mrq)
383{
384 struct mrq_query_abi_request req = { .mrq = cpu_to_le32(mrq) };
385 struct mrq_query_abi_response resp;
386 struct tegra_bpmp_message msg = {
387 .mrq = MRQ_QUERY_ABI,
388 .tx = {
389 .data = &req,
390 .size = sizeof(req),
391 },
392 .rx = {
393 .data = &resp,
394 .size = sizeof(resp),
395 },
396 };
397 int ret;
398
399 ret = tegra_bpmp_transfer(bpmp, &msg);
400 if (ret < 0) {
401 /* something went wrong; assume not supported */
402 dev_warn(bpmp->dev, "tegra_bpmp_transfer failed (%d)\n", ret);
403 return 0;
404 }
405
406 return resp.status ? 0 : 1;
407}
408
409int tegra_bpmp_init_debugfs(struct tegra_bpmp *bpmp)
410{
411 dma_addr_t phys;
412 void *virt;
413 const size_t sz = SZ_256K;
414 size_t nbytes;
415 int ret;
416 struct dentry *root;
417
418 if (!mrq_is_supported(bpmp, MRQ_DEBUGFS))
419 return 0;
420
421 root = debugfs_create_dir("bpmp", NULL);
422 if (!root)
423 return -ENOMEM;
424
425 virt = dma_alloc_coherent(bpmp->dev, sz, &phys,
426 GFP_KERNEL | GFP_DMA32);
427 if (!virt) {
428 ret = -ENOMEM;
429 goto out;
430 }
431
432 ret = mrq_debugfs_dumpdir(bpmp, phys, sz, &nbytes);
433 if (ret < 0)
434 goto free;
435
436 ret = create_debugfs_mirror(bpmp, virt, nbytes, root);
437free:
438 dma_free_coherent(bpmp->dev, sz, virt, phys);
439out:
440 if (ret < 0)
441 debugfs_remove(root);
442
443 return ret;
444}