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1/*
2 * Copyright (C) 2013 Red Hat
3 * Author: Rob Clark <robdclark@gmail.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 as published by
7 * the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18/* For debugging crashes, userspace can:
19 *
20 * tail -f /sys/kernel/debug/dri/<minor>/rd > logfile.rd
21 *
22 * To log the cmdstream in a format that is understood by freedreno/cffdump
23 * utility. By comparing the last successfully completed fence #, to the
24 * cmdstream for the next fence, you can narrow down which process and submit
25 * caused the gpu crash/lockup.
26 *
27 * This bypasses drm_debugfs_create_files() mainly because we need to use
28 * our own fops for a bit more control. In particular, we don't want to
29 * do anything if userspace doesn't have the debugfs file open.
30 *
31 * The module-param "rd_full", which defaults to false, enables snapshotting
32 * all (non-written) buffers in the submit, rather than just cmdstream bo's.
33 * This is useful to capture the contents of (for example) vbo's or textures,
34 * or shader programs (if not emitted inline in cmdstream).
35 */
36
37#ifdef CONFIG_DEBUG_FS
38
39#include <linux/kfifo.h>
40#include <linux/debugfs.h>
41#include <linux/circ_buf.h>
42#include <linux/wait.h>
43
44#include "msm_drv.h"
45#include "msm_gpu.h"
46#include "msm_gem.h"
47
48static bool rd_full = false;
49MODULE_PARM_DESC(rd_full, "If true, $debugfs/.../rd will snapshot all buffer contents");
50module_param_named(rd_full, rd_full, bool, 0600);
51
52enum rd_sect_type {
53 RD_NONE,
54 RD_TEST, /* ascii text */
55 RD_CMD, /* ascii text */
56 RD_GPUADDR, /* u32 gpuaddr, u32 size */
57 RD_CONTEXT, /* raw dump */
58 RD_CMDSTREAM, /* raw dump */
59 RD_CMDSTREAM_ADDR, /* gpu addr of cmdstream */
60 RD_PARAM, /* u32 param_type, u32 param_val, u32 bitlen */
61 RD_FLUSH, /* empty, clear previous params */
62 RD_PROGRAM, /* shader program, raw dump */
63 RD_VERT_SHADER,
64 RD_FRAG_SHADER,
65 RD_BUFFER_CONTENTS,
66 RD_GPU_ID,
67};
68
69#define BUF_SZ 512 /* should be power of 2 */
70
71/* space used: */
72#define circ_count(circ) \
73 (CIRC_CNT((circ)->head, (circ)->tail, BUF_SZ))
74#define circ_count_to_end(circ) \
75 (CIRC_CNT_TO_END((circ)->head, (circ)->tail, BUF_SZ))
76/* space available: */
77#define circ_space(circ) \
78 (CIRC_SPACE((circ)->head, (circ)->tail, BUF_SZ))
79#define circ_space_to_end(circ) \
80 (CIRC_SPACE_TO_END((circ)->head, (circ)->tail, BUF_SZ))
81
82struct msm_rd_state {
83 struct drm_device *dev;
84
85 bool open;
86
87 struct dentry *ent;
88 struct drm_info_node *node;
89
90 /* current submit to read out: */
91 struct msm_gem_submit *submit;
92
93 /* fifo access is synchronized on the producer side by
94 * struct_mutex held by submit code (otherwise we could
95 * end up w/ cmds logged in different order than they
96 * were executed). And read_lock synchronizes the reads
97 */
98 struct mutex read_lock;
99
100 wait_queue_head_t fifo_event;
101 struct circ_buf fifo;
102
103 char buf[BUF_SZ];
104};
105
106static void rd_write(struct msm_rd_state *rd, const void *buf, int sz)
107{
108 struct circ_buf *fifo = &rd->fifo;
109 const char *ptr = buf;
110
111 while (sz > 0) {
112 char *fptr = &fifo->buf[fifo->head];
113 int n;
114
115 wait_event(rd->fifo_event, circ_space(&rd->fifo) > 0);
116
117 n = min(sz, circ_space_to_end(&rd->fifo));
118 memcpy(fptr, ptr, n);
119
120 fifo->head = (fifo->head + n) & (BUF_SZ - 1);
121 sz -= n;
122 ptr += n;
123
124 wake_up_all(&rd->fifo_event);
125 }
126}
127
128static void rd_write_section(struct msm_rd_state *rd,
129 enum rd_sect_type type, const void *buf, int sz)
130{
131 rd_write(rd, &type, 4);
132 rd_write(rd, &sz, 4);
133 rd_write(rd, buf, sz);
134}
135
136static ssize_t rd_read(struct file *file, char __user *buf,
137 size_t sz, loff_t *ppos)
138{
139 struct msm_rd_state *rd = file->private_data;
140 struct circ_buf *fifo = &rd->fifo;
141 const char *fptr = &fifo->buf[fifo->tail];
142 int n = 0, ret = 0;
143
144 mutex_lock(&rd->read_lock);
145
146 ret = wait_event_interruptible(rd->fifo_event,
147 circ_count(&rd->fifo) > 0);
148 if (ret)
149 goto out;
150
151 n = min_t(int, sz, circ_count_to_end(&rd->fifo));
152 if (copy_to_user(buf, fptr, n)) {
153 ret = -EFAULT;
154 goto out;
155 }
156
157 fifo->tail = (fifo->tail + n) & (BUF_SZ - 1);
158 *ppos += n;
159
160 wake_up_all(&rd->fifo_event);
161
162out:
163 mutex_unlock(&rd->read_lock);
164 if (ret)
165 return ret;
166 return n;
167}
168
169static int rd_open(struct inode *inode, struct file *file)
170{
171 struct msm_rd_state *rd = inode->i_private;
172 struct drm_device *dev = rd->dev;
173 struct msm_drm_private *priv = dev->dev_private;
174 struct msm_gpu *gpu = priv->gpu;
175 uint64_t val;
176 uint32_t gpu_id;
177 int ret = 0;
178
179 mutex_lock(&dev->struct_mutex);
180
181 if (rd->open || !gpu) {
182 ret = -EBUSY;
183 goto out;
184 }
185
186 file->private_data = rd;
187 rd->open = true;
188
189 /* the parsing tools need to know gpu-id to know which
190 * register database to load.
191 */
192 gpu->funcs->get_param(gpu, MSM_PARAM_GPU_ID, &val);
193 gpu_id = val;
194
195 rd_write_section(rd, RD_GPU_ID, &gpu_id, sizeof(gpu_id));
196
197out:
198 mutex_unlock(&dev->struct_mutex);
199 return ret;
200}
201
202static int rd_release(struct inode *inode, struct file *file)
203{
204 struct msm_rd_state *rd = inode->i_private;
205 rd->open = false;
206 return 0;
207}
208
209
210static const struct file_operations rd_debugfs_fops = {
211 .owner = THIS_MODULE,
212 .open = rd_open,
213 .read = rd_read,
214 .llseek = no_llseek,
215 .release = rd_release,
216};
217
218int msm_rd_debugfs_init(struct drm_minor *minor)
219{
220 struct msm_drm_private *priv = minor->dev->dev_private;
221 struct msm_rd_state *rd;
222
223 /* only create on first minor: */
224 if (priv->rd)
225 return 0;
226
227 rd = kzalloc(sizeof(*rd), GFP_KERNEL);
228 if (!rd)
229 return -ENOMEM;
230
231 rd->dev = minor->dev;
232 rd->fifo.buf = rd->buf;
233
234 mutex_init(&rd->read_lock);
235 priv->rd = rd;
236
237 init_waitqueue_head(&rd->fifo_event);
238
239 rd->node = kzalloc(sizeof(*rd->node), GFP_KERNEL);
240 if (!rd->node)
241 goto fail;
242
243 rd->ent = debugfs_create_file("rd", S_IFREG | S_IRUGO,
244 minor->debugfs_root, rd, &rd_debugfs_fops);
245 if (!rd->ent) {
246 DRM_ERROR("Cannot create /sys/kernel/debug/dri/%pd/rd\n",
247 minor->debugfs_root);
248 goto fail;
249 }
250
251 rd->node->minor = minor;
252 rd->node->dent = rd->ent;
253 rd->node->info_ent = NULL;
254
255 mutex_lock(&minor->debugfs_lock);
256 list_add(&rd->node->list, &minor->debugfs_list);
257 mutex_unlock(&minor->debugfs_lock);
258
259 return 0;
260
261fail:
262 msm_rd_debugfs_cleanup(minor);
263 return -1;
264}
265
266void msm_rd_debugfs_cleanup(struct drm_minor *minor)
267{
268 struct msm_drm_private *priv = minor->dev->dev_private;
269 struct msm_rd_state *rd = priv->rd;
270
271 if (!rd)
272 return;
273
274 priv->rd = NULL;
275
276 debugfs_remove(rd->ent);
277
278 if (rd->node) {
279 mutex_lock(&minor->debugfs_lock);
280 list_del(&rd->node->list);
281 mutex_unlock(&minor->debugfs_lock);
282 kfree(rd->node);
283 }
284
285 mutex_destroy(&rd->read_lock);
286
287 kfree(rd);
288}
289
290static void snapshot_buf(struct msm_rd_state *rd,
291 struct msm_gem_submit *submit, int idx,
292 uint64_t iova, uint32_t size)
293{
294 struct msm_gem_object *obj = submit->bos[idx].obj;
295 const char *buf;
296
297 buf = msm_gem_get_vaddr_locked(&obj->base);
298 if (IS_ERR(buf))
299 return;
300
301 if (iova) {
302 buf += iova - submit->bos[idx].iova;
303 } else {
304 iova = submit->bos[idx].iova;
305 size = obj->base.size;
306 }
307
308 rd_write_section(rd, RD_GPUADDR,
309 (uint32_t[3]){ iova, size, iova >> 32 }, 12);
310 rd_write_section(rd, RD_BUFFER_CONTENTS, buf, size);
311
312 msm_gem_put_vaddr_locked(&obj->base);
313}
314
315/* called under struct_mutex */
316void msm_rd_dump_submit(struct msm_gem_submit *submit)
317{
318 struct drm_device *dev = submit->dev;
319 struct msm_drm_private *priv = dev->dev_private;
320 struct msm_rd_state *rd = priv->rd;
321 char msg[128];
322 int i, n;
323
324 if (!rd->open)
325 return;
326
327 /* writing into fifo is serialized by caller, and
328 * rd->read_lock is used to serialize the reads
329 */
330 WARN_ON(!mutex_is_locked(&dev->struct_mutex));
331
332 n = snprintf(msg, sizeof(msg), "%.*s/%d: fence=%u",
333 TASK_COMM_LEN, current->comm, task_pid_nr(current),
334 submit->fence->seqno);
335
336 rd_write_section(rd, RD_CMD, msg, ALIGN(n, 4));
337
338 if (rd_full) {
339 for (i = 0; i < submit->nr_bos; i++) {
340 /* buffers that are written to probably don't start out
341 * with anything interesting:
342 */
343 if (submit->bos[i].flags & MSM_SUBMIT_BO_WRITE)
344 continue;
345
346 snapshot_buf(rd, submit, i, 0, 0);
347 }
348 }
349
350 for (i = 0; i < submit->nr_cmds; i++) {
351 uint32_t iova = submit->cmd[i].iova;
352 uint32_t szd = submit->cmd[i].size; /* in dwords */
353
354 /* snapshot cmdstream bo's (if we haven't already): */
355 if (!rd_full) {
356 snapshot_buf(rd, submit, submit->cmd[i].idx,
357 submit->cmd[i].iova, szd * 4);
358 }
359
360 switch (submit->cmd[i].type) {
361 case MSM_SUBMIT_CMD_IB_TARGET_BUF:
362 /* ignore IB-targets, we've logged the buffer, the
363 * parser tool will follow the IB based on the logged
364 * buffer/gpuaddr, so nothing more to do.
365 */
366 break;
367 case MSM_SUBMIT_CMD_CTX_RESTORE_BUF:
368 case MSM_SUBMIT_CMD_BUF:
369 rd_write_section(rd, RD_CMDSTREAM_ADDR,
370 (uint32_t[2]){ iova, szd }, 8);
371 break;
372 }
373 }
374}
375#endif