summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/msm/msm_rd.c
blob: ec56794ad0399277693b9185c75b6abcf9241e4a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
/*
 * Copyright (C) 2013 Red Hat
 * Author: Rob Clark <robdclark@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/* For debugging crashes, userspace can:
 *
 *   tail -f /sys/kernel/debug/dri/<minor>/rd > logfile.rd
 *
 * To log the cmdstream in a format that is understood by freedreno/cffdump
 * utility.  By comparing the last successfully completed fence #, to the
 * cmdstream for the next fence, you can narrow down which process and submit
 * caused the gpu crash/lockup.
 *
 * This bypasses drm_debugfs_create_files() mainly because we need to use
 * our own fops for a bit more control.  In particular, we don't want to
 * do anything if userspace doesn't have the debugfs file open.
 *
 * The module-param "rd_full", which defaults to false, enables snapshotting
 * all (non-written) buffers in the submit, rather than just cmdstream bo's.
 * This is useful to capture the contents of (for example) vbo's or textures,
 * or shader programs (if not emitted inline in cmdstream).
 */

#ifdef CONFIG_DEBUG_FS

#include <linux/kfifo.h>
#include <linux/debugfs.h>
#include <linux/circ_buf.h>
#include <linux/wait.h>

#include "msm_drv.h"
#include "msm_gpu.h"
#include "msm_gem.h"

static bool rd_full = false;
MODULE_PARM_DESC(rd_full, "If true, $debugfs/.../rd will snapshot all buffer contents");
module_param_named(rd_full, rd_full, bool, 0600);

enum rd_sect_type {
	RD_NONE,
	RD_TEST,       /* ascii text */
	RD_CMD,        /* ascii text */
	RD_GPUADDR,    /* u32 gpuaddr, u32 size */
	RD_CONTEXT,    /* raw dump */
	RD_CMDSTREAM,  /* raw dump */
	RD_CMDSTREAM_ADDR, /* gpu addr of cmdstream */
	RD_PARAM,      /* u32 param_type, u32 param_val, u32 bitlen */
	RD_FLUSH,      /* empty, clear previous params */
	RD_PROGRAM,    /* shader program, raw dump */
	RD_VERT_SHADER,
	RD_FRAG_SHADER,
	RD_BUFFER_CONTENTS,
	RD_GPU_ID,
};

#define BUF_SZ 512  /* should be power of 2 */

/* space used: */
#define circ_count(circ) \
	(CIRC_CNT((circ)->head, (circ)->tail, BUF_SZ))
#define circ_count_to_end(circ) \
	(CIRC_CNT_TO_END((circ)->head, (circ)->tail, BUF_SZ))
/* space available: */
#define circ_space(circ) \
	(CIRC_SPACE((circ)->head, (circ)->tail, BUF_SZ))
#define circ_space_to_end(circ) \
	(CIRC_SPACE_TO_END((circ)->head, (circ)->tail, BUF_SZ))

struct msm_rd_state {
	struct drm_device *dev;

	bool open;

	/* current submit to read out: */
	struct msm_gem_submit *submit;

	/* fifo access is synchronized on the producer side by
	 * struct_mutex held by submit code (otherwise we could
	 * end up w/ cmds logged in different order than they
	 * were executed).  And read_lock synchronizes the reads
	 */
	struct mutex read_lock;

	wait_queue_head_t fifo_event;
	struct circ_buf fifo;

	char buf[BUF_SZ];
};

static void rd_write(struct msm_rd_state *rd, const void *buf, int sz)
{
	struct circ_buf *fifo = &rd->fifo;
	const char *ptr = buf;

	while (sz > 0) {
		char *fptr = &fifo->buf[fifo->head];
		int n;

		wait_event(rd->fifo_event, circ_space(&rd->fifo) > 0);

		/* Note that smp_load_acquire() is not strictly required
		 * as CIRC_SPACE_TO_END() does not access the tail more
		 * than once.
		 */
		n = min(sz, circ_space_to_end(&rd->fifo));
		memcpy(fptr, ptr, n);

		smp_store_release(&fifo->head, (fifo->head + n) & (BUF_SZ - 1));
		sz  -= n;
		ptr += n;

		wake_up_all(&rd->fifo_event);
	}
}

static void rd_write_section(struct msm_rd_state *rd,
		enum rd_sect_type type, const void *buf, int sz)
{
	rd_write(rd, &type, 4);
	rd_write(rd, &sz, 4);
	rd_write(rd, buf, sz);
}

static ssize_t rd_read(struct file *file, char __user *buf,
		size_t sz, loff_t *ppos)
{
	struct msm_rd_state *rd = file->private_data;
	struct circ_buf *fifo = &rd->fifo;
	const char *fptr = &fifo->buf[fifo->tail];
	int n = 0, ret = 0;

	mutex_lock(&rd->read_lock);

	ret = wait_event_interruptible(rd->fifo_event,
			circ_count(&rd->fifo) > 0);
	if (ret)
		goto out;

	/* Note that smp_load_acquire() is not strictly required
	 * as CIRC_CNT_TO_END() does not access the head more than
	 * once.
	 */
	n = min_t(int, sz, circ_count_to_end(&rd->fifo));
	if (copy_to_user(buf, fptr, n)) {
		ret = -EFAULT;
		goto out;
	}

	smp_store_release(&fifo->tail, (fifo->tail + n) & (BUF_SZ - 1));
	*ppos += n;

	wake_up_all(&rd->fifo_event);

out:
	mutex_unlock(&rd->read_lock);
	if (ret)
		return ret;
	return n;
}

static int rd_open(struct inode *inode, struct file *file)
{
	struct msm_rd_state *rd = inode->i_private;
	struct drm_device *dev = rd->dev;
	struct msm_drm_private *priv = dev->dev_private;
	struct msm_gpu *gpu = priv->gpu;
	uint64_t val;
	uint32_t gpu_id;
	int ret = 0;

	mutex_lock(&dev->struct_mutex);

	if (rd->open || !gpu) {
		ret = -EBUSY;
		goto out;
	}

	file->private_data = rd;
	rd->open = true;

	/* the parsing tools need to know gpu-id to know which
	 * register database to load.
	 */
	gpu->funcs->get_param(gpu, MSM_PARAM_GPU_ID, &val);
	gpu_id = val;

	rd_write_section(rd, RD_GPU_ID, &gpu_id, sizeof(gpu_id));

out:
	mutex_unlock(&dev->struct_mutex);
	return ret;
}

static int rd_release(struct inode *inode, struct file *file)
{
	struct msm_rd_state *rd = inode->i_private;
	rd->open = false;
	return 0;
}


static const struct file_operations rd_debugfs_fops = {
	.owner = THIS_MODULE,
	.open = rd_open,
	.read = rd_read,
	.llseek = no_llseek,
	.release = rd_release,
};

int msm_rd_debugfs_init(struct drm_minor *minor)
{
	struct msm_drm_private *priv = minor->dev->dev_private;
	struct msm_rd_state *rd;
	struct dentry *ent;

	/* only create on first minor: */
	if (priv->rd)
		return 0;

	rd = kzalloc(sizeof(*rd), GFP_KERNEL);
	if (!rd)
		return -ENOMEM;

	rd->dev = minor->dev;
	rd->fifo.buf = rd->buf;

	mutex_init(&rd->read_lock);
	priv->rd = rd;

	init_waitqueue_head(&rd->fifo_event);

	ent = debugfs_create_file("rd", S_IFREG | S_IRUGO,
			minor->debugfs_root, rd, &rd_debugfs_fops);
	if (!ent) {
		DRM_ERROR("Cannot create /sys/kernel/debug/dri/%pd/rd\n",
				minor->debugfs_root);
		goto fail;
	}

	return 0;

fail:
	msm_rd_debugfs_cleanup(priv);
	return -1;
}

void msm_rd_debugfs_cleanup(struct msm_drm_private *priv)
{
	struct msm_rd_state *rd = priv->rd;

	if (!rd)
		return;

	priv->rd = NULL;
	mutex_destroy(&rd->read_lock);
	kfree(rd);
}

static void snapshot_buf(struct msm_rd_state *rd,
		struct msm_gem_submit *submit, int idx,
		uint64_t iova, uint32_t size)
{
	struct msm_gem_object *obj = submit->bos[idx].obj;
	const char *buf;

	buf = msm_gem_get_vaddr(&obj->base);
	if (IS_ERR(buf))
		return;

	if (iova) {
		buf += iova - submit->bos[idx].iova;
	} else {
		iova = submit->bos[idx].iova;
		size = obj->base.size;
	}

	rd_write_section(rd, RD_GPUADDR,
			(uint32_t[3]){ iova, size, iova >> 32 }, 12);
	rd_write_section(rd, RD_BUFFER_CONTENTS, buf, size);

	msm_gem_put_vaddr(&obj->base);
}

/* called under struct_mutex */
void msm_rd_dump_submit(struct msm_gem_submit *submit)
{
	struct drm_device *dev = submit->dev;
	struct msm_drm_private *priv = dev->dev_private;
	struct msm_rd_state *rd = priv->rd;
	char msg[128];
	int i, n;

	if (!rd->open)
		return;

	/* writing into fifo is serialized by caller, and
	 * rd->read_lock is used to serialize the reads
	 */
	WARN_ON(!mutex_is_locked(&dev->struct_mutex));

	n = snprintf(msg, sizeof(msg), "%.*s/%d: fence=%u",
			TASK_COMM_LEN, current->comm, task_pid_nr(current),
			submit->fence->seqno);

	rd_write_section(rd, RD_CMD, msg, ALIGN(n, 4));

	if (rd_full) {
		for (i = 0; i < submit->nr_bos; i++) {
			/* buffers that are written to probably don't start out
			 * with anything interesting:
			 */
			if (submit->bos[i].flags & MSM_SUBMIT_BO_WRITE)
				continue;

			snapshot_buf(rd, submit, i, 0, 0);
		}
	}

	for (i = 0; i < submit->nr_cmds; i++) {
		uint64_t iova = submit->cmd[i].iova;
		uint32_t szd  = submit->cmd[i].size; /* in dwords */

		/* snapshot cmdstream bo's (if we haven't already): */
		if (!rd_full) {
			snapshot_buf(rd, submit, submit->cmd[i].idx,
					submit->cmd[i].iova, szd * 4);
		}

		switch (submit->cmd[i].type) {
		case MSM_SUBMIT_CMD_IB_TARGET_BUF:
			/* ignore IB-targets, we've logged the buffer, the
			 * parser tool will follow the IB based on the logged
			 * buffer/gpuaddr, so nothing more to do.
			 */
			break;
		case MSM_SUBMIT_CMD_CTX_RESTORE_BUF:
		case MSM_SUBMIT_CMD_BUF:
			rd_write_section(rd, RD_CMDSTREAM_ADDR,
				(uint32_t[3]){ iova, szd, iova >> 32 }, 12);
			break;
		}
	}
}
#endif