2 * Copyright (C) 2013 Red Hat
3 * Author: Rob Clark <robdclark@gmail.com>
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.
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
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/>.
18 /* For debugging crashes, userspace can:
20 * tail -f /sys/kernel/debug/dri/<minor>/rd > logfile.rd
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.
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.
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).
37 #ifdef CONFIG_DEBUG_FS
39 #include <linux/kfifo.h>
40 #include <linux/debugfs.h>
41 #include <linux/circ_buf.h>
42 #include <linux/wait.h>
48 static bool rd_full = false;
49 MODULE_PARM_DESC(rd_full, "If true, $debugfs/.../rd will snapshot all buffer contents");
50 module_param_named(rd_full, rd_full, bool, 0600);
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 */
69 #define BUF_SZ 512 /* should be power of 2 */
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))
83 struct drm_device *dev;
88 struct drm_info_node *node;
90 /* current submit to read out: */
91 struct msm_gem_submit *submit;
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
98 struct mutex read_lock;
100 wait_queue_head_t fifo_event;
101 struct circ_buf fifo;
106 static void rd_write(struct msm_rd_state *rd, const void *buf, int sz)
108 struct circ_buf *fifo = &rd->fifo;
109 const char *ptr = buf;
112 char *fptr = &fifo->buf[fifo->head];
115 wait_event(rd->fifo_event, circ_space(&rd->fifo) > 0);
117 n = min(sz, circ_space_to_end(&rd->fifo));
118 memcpy(fptr, ptr, n);
120 fifo->head = (fifo->head + n) & (BUF_SZ - 1);
124 wake_up_all(&rd->fifo_event);
128 static void rd_write_section(struct msm_rd_state *rd,
129 enum rd_sect_type type, const void *buf, int sz)
131 rd_write(rd, &type, 4);
132 rd_write(rd, &sz, 4);
133 rd_write(rd, buf, sz);
136 static ssize_t rd_read(struct file *file, char __user *buf,
137 size_t sz, loff_t *ppos)
139 struct msm_rd_state *rd = file->private_data;
140 struct circ_buf *fifo = &rd->fifo;
141 const char *fptr = &fifo->buf[fifo->tail];
144 mutex_lock(&rd->read_lock);
146 ret = wait_event_interruptible(rd->fifo_event,
147 circ_count(&rd->fifo) > 0);
151 n = min_t(int, sz, circ_count_to_end(&rd->fifo));
152 ret = copy_to_user(buf, fptr, n);
156 fifo->tail = (fifo->tail + n) & (BUF_SZ - 1);
159 wake_up_all(&rd->fifo_event);
162 mutex_unlock(&rd->read_lock);
168 static int rd_open(struct inode *inode, struct file *file)
170 struct msm_rd_state *rd = inode->i_private;
171 struct drm_device *dev = rd->dev;
172 struct msm_drm_private *priv = dev->dev_private;
173 struct msm_gpu *gpu = priv->gpu;
178 mutex_lock(&dev->struct_mutex);
180 if (rd->open || !gpu) {
185 file->private_data = rd;
188 /* the parsing tools need to know gpu-id to know which
189 * register database to load.
191 gpu->funcs->get_param(gpu, MSM_PARAM_GPU_ID, &val);
194 rd_write_section(rd, RD_GPU_ID, &gpu_id, sizeof(gpu_id));
197 mutex_unlock(&dev->struct_mutex);
201 static int rd_release(struct inode *inode, struct file *file)
203 struct msm_rd_state *rd = inode->i_private;
209 static const struct file_operations rd_debugfs_fops = {
210 .owner = THIS_MODULE,
214 .release = rd_release,
217 int msm_rd_debugfs_init(struct drm_minor *minor)
219 struct msm_drm_private *priv = minor->dev->dev_private;
220 struct msm_rd_state *rd;
222 /* only create on first minor: */
226 rd = kzalloc(sizeof(*rd), GFP_KERNEL);
230 rd->dev = minor->dev;
231 rd->fifo.buf = rd->buf;
233 mutex_init(&rd->read_lock);
236 init_waitqueue_head(&rd->fifo_event);
238 rd->node = kzalloc(sizeof(*rd->node), GFP_KERNEL);
242 rd->ent = debugfs_create_file("rd", S_IFREG | S_IRUGO,
243 minor->debugfs_root, rd, &rd_debugfs_fops);
245 DRM_ERROR("Cannot create /sys/kernel/debug/dri/%s/rd\n",
246 minor->debugfs_root->d_name.name);
250 rd->node->minor = minor;
251 rd->node->dent = rd->ent;
252 rd->node->info_ent = NULL;
254 mutex_lock(&minor->debugfs_lock);
255 list_add(&rd->node->list, &minor->debugfs_list);
256 mutex_unlock(&minor->debugfs_lock);
261 msm_rd_debugfs_cleanup(minor);
265 void msm_rd_debugfs_cleanup(struct drm_minor *minor)
267 struct msm_drm_private *priv = minor->dev->dev_private;
268 struct msm_rd_state *rd = priv->rd;
275 debugfs_remove(rd->ent);
278 mutex_lock(&minor->debugfs_lock);
279 list_del(&rd->node->list);
280 mutex_unlock(&minor->debugfs_lock);
284 mutex_destroy(&rd->read_lock);
289 static void snapshot_buf(struct msm_rd_state *rd,
290 struct msm_gem_submit *submit, int idx,
291 uint32_t iova, uint32_t size)
293 struct msm_gem_object *obj = submit->bos[idx].obj;
296 buf = msm_gem_get_vaddr_locked(&obj->base);
301 buf += iova - submit->bos[idx].iova;
303 iova = submit->bos[idx].iova;
304 size = obj->base.size;
307 rd_write_section(rd, RD_GPUADDR,
308 (uint32_t[2]){ iova, size }, 8);
309 rd_write_section(rd, RD_BUFFER_CONTENTS, buf, size);
311 msm_gem_put_vaddr_locked(&obj->base);
314 /* called under struct_mutex */
315 void msm_rd_dump_submit(struct msm_gem_submit *submit)
317 struct drm_device *dev = submit->dev;
318 struct msm_drm_private *priv = dev->dev_private;
319 struct msm_rd_state *rd = priv->rd;
326 /* writing into fifo is serialized by caller, and
327 * rd->read_lock is used to serialize the reads
329 WARN_ON(!mutex_is_locked(&dev->struct_mutex));
331 n = snprintf(msg, sizeof(msg), "%.*s/%d: fence=%u",
332 TASK_COMM_LEN, current->comm, task_pid_nr(current),
333 submit->fence->seqno);
335 rd_write_section(rd, RD_CMD, msg, ALIGN(n, 4));
338 for (i = 0; i < submit->nr_bos; i++) {
339 /* buffers that are written to probably don't start out
340 * with anything interesting:
342 if (submit->bos[i].flags & MSM_SUBMIT_BO_WRITE)
345 snapshot_buf(rd, submit, i, 0, 0);
349 for (i = 0; i < submit->nr_cmds; i++) {
350 uint32_t iova = submit->cmd[i].iova;
351 uint32_t szd = submit->cmd[i].size; /* in dwords */
353 /* snapshot cmdstream bo's (if we haven't already): */
355 snapshot_buf(rd, submit, submit->cmd[i].idx,
356 submit->cmd[i].iova, szd * 4);
359 switch (submit->cmd[i].type) {
360 case MSM_SUBMIT_CMD_IB_TARGET_BUF:
361 /* ignore IB-targets, we've logged the buffer, the
362 * parser tool will follow the IB based on the logged
363 * buffer/gpuaddr, so nothing more to do.
366 case MSM_SUBMIT_CMD_CTX_RESTORE_BUF:
367 case MSM_SUBMIT_CMD_BUF:
368 rd_write_section(rd, RD_CMDSTREAM_ADDR,
369 (uint32_t[2]){ iova, szd }, 8);