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25 #include <linux/debugfs.h>
26 #include <linux/relay.h>
28 #include "intel_guc_log.h"
32 static void guc_log_capture_logs(struct intel_guc *guc);
35 * DOC: GuC firmware log
37 * Firmware log is enabled by setting i915.guc_log_level to non-negative level.
38 * Log data is printed out via reading debugfs i915_guc_log_dump. Reading from
39 * i915_guc_load_status will print out firmware loading status and scratch
44 static int guc_log_flush_complete(struct intel_guc *guc)
47 INTEL_GUC_ACTION_LOG_BUFFER_FILE_FLUSH_COMPLETE
50 return intel_guc_send(guc, action, ARRAY_SIZE(action));
53 static int guc_log_flush(struct intel_guc *guc)
56 INTEL_GUC_ACTION_FORCE_LOG_BUFFER_FLUSH,
60 return intel_guc_send(guc, action, ARRAY_SIZE(action));
63 static int guc_log_control(struct intel_guc *guc, u32 control_val)
66 INTEL_GUC_ACTION_UK_LOG_ENABLE_LOGGING,
70 return intel_guc_send(guc, action, ARRAY_SIZE(action));
74 * Sub buffer switch callback. Called whenever relay has to switch to a new
75 * sub buffer, relay stays on the same sub buffer if 0 is returned.
77 static int subbuf_start_callback(struct rchan_buf *buf,
82 /* Use no-overwrite mode by default, where relay will stop accepting
83 * new data if there are no empty sub buffers left.
84 * There is no strict synchronization enforced by relay between Consumer
85 * and Producer. In overwrite mode, there is a possibility of getting
86 * inconsistent/garbled data, the producer could be writing on to the
87 * same sub buffer from which Consumer is reading. This can't be avoided
88 * unless Consumer is fast enough and can always run in tandem with
91 if (relay_buf_full(buf))
98 * file_create() callback. Creates relay file in debugfs.
100 static struct dentry *create_buf_file_callback(const char *filename,
101 struct dentry *parent,
103 struct rchan_buf *buf,
106 struct dentry *buf_file;
108 /* This to enable the use of a single buffer for the relay channel and
109 * correspondingly have a single file exposed to User, through which
110 * it can collect the logs in order without any post-processing.
111 * Need to set 'is_global' even if parent is NULL for early logging.
118 /* Not using the channel filename passed as an argument, since for each
119 * channel relay appends the corresponding CPU number to the filename
120 * passed in relay_open(). This should be fine as relay just needs a
121 * dentry of the file associated with the channel buffer and that file's
122 * name need not be same as the filename passed as an argument.
124 buf_file = debugfs_create_file("guc_log", mode,
125 parent, buf, &relay_file_operations);
130 * file_remove() default callback. Removes relay file in debugfs.
132 static int remove_buf_file_callback(struct dentry *dentry)
134 debugfs_remove(dentry);
138 /* relay channel callbacks */
139 static struct rchan_callbacks relay_callbacks = {
140 .subbuf_start = subbuf_start_callback,
141 .create_buf_file = create_buf_file_callback,
142 .remove_buf_file = remove_buf_file_callback,
145 static int guc_log_relay_file_create(struct intel_guc *guc)
147 struct drm_i915_private *dev_priv = guc_to_i915(guc);
148 struct dentry *log_dir;
151 if (i915_modparams.guc_log_level < 0)
154 /* For now create the log file in /sys/kernel/debug/dri/0 dir */
155 log_dir = dev_priv->drm.primary->debugfs_root;
157 /* If /sys/kernel/debug/dri/0 location do not exist, then debugfs is
158 * not mounted and so can't create the relay file.
159 * The relay API seems to fit well with debugfs only, for availing relay
160 * there are 3 requirements which can be met for debugfs file only in a
161 * straightforward/clean manner :-
162 * i) Need the associated dentry pointer of the file, while opening the
164 * ii) Should be able to use 'relay_file_operations' fops for the file.
165 * iii) Set the 'i_private' field of file's inode to the pointer of
166 * relay channel buffer.
169 DRM_ERROR("Debugfs dir not available yet for GuC log file\n");
173 ret = relay_late_setup_files(guc->log.runtime.relay_chan, "guc_log", log_dir);
174 if (ret < 0 && ret != -EEXIST) {
175 DRM_ERROR("Couldn't associate relay chan with file %d\n", ret);
182 static void guc_move_to_next_buf(struct intel_guc *guc)
184 /* Make sure the updates made in the sub buffer are visible when
185 * Consumer sees the following update to offset inside the sub buffer.
189 /* All data has been written, so now move the offset of sub buffer. */
190 relay_reserve(guc->log.runtime.relay_chan, guc->log.vma->obj->base.size);
192 /* Switch to the next sub buffer */
193 relay_flush(guc->log.runtime.relay_chan);
196 static void *guc_get_write_buffer(struct intel_guc *guc)
198 if (!guc->log.runtime.relay_chan)
201 /* Just get the base address of a new sub buffer and copy data into it
202 * ourselves. NULL will be returned in no-overwrite mode, if all sub
203 * buffers are full. Could have used the relay_write() to indirectly
204 * copy the data, but that would have been bit convoluted, as we need to
205 * write to only certain locations inside a sub buffer which cannot be
206 * done without using relay_reserve() along with relay_write(). So its
207 * better to use relay_reserve() alone.
209 return relay_reserve(guc->log.runtime.relay_chan, 0);
212 static bool guc_check_log_buf_overflow(struct intel_guc *guc,
213 enum guc_log_buffer_type type,
214 unsigned int full_cnt)
216 unsigned int prev_full_cnt = guc->log.prev_overflow_count[type];
217 bool overflow = false;
219 if (full_cnt != prev_full_cnt) {
222 guc->log.prev_overflow_count[type] = full_cnt;
223 guc->log.total_overflow_count[type] += full_cnt - prev_full_cnt;
225 if (full_cnt < prev_full_cnt) {
226 /* buffer_full_cnt is a 4 bit counter */
227 guc->log.total_overflow_count[type] += 16;
229 DRM_ERROR_RATELIMITED("GuC log buffer overflow\n");
235 static unsigned int guc_get_log_buffer_size(enum guc_log_buffer_type type)
238 case GUC_ISR_LOG_BUFFER:
239 return (GUC_LOG_ISR_PAGES + 1) * PAGE_SIZE;
240 case GUC_DPC_LOG_BUFFER:
241 return (GUC_LOG_DPC_PAGES + 1) * PAGE_SIZE;
242 case GUC_CRASH_DUMP_LOG_BUFFER:
243 return (GUC_LOG_CRASH_PAGES + 1) * PAGE_SIZE;
251 static void guc_read_update_log_buffer(struct intel_guc *guc)
253 unsigned int buffer_size, read_offset, write_offset, bytes_to_copy, full_cnt;
254 struct guc_log_buffer_state *log_buf_state, *log_buf_snapshot_state;
255 struct guc_log_buffer_state log_buf_state_local;
256 enum guc_log_buffer_type type;
257 void *src_data, *dst_data;
260 if (WARN_ON(!guc->log.runtime.buf_addr))
263 /* Get the pointer to shared GuC log buffer */
264 log_buf_state = src_data = guc->log.runtime.buf_addr;
266 /* Get the pointer to local buffer to store the logs */
267 log_buf_snapshot_state = dst_data = guc_get_write_buffer(guc);
269 /* Actual logs are present from the 2nd page */
270 src_data += PAGE_SIZE;
271 dst_data += PAGE_SIZE;
273 for (type = GUC_ISR_LOG_BUFFER; type < GUC_MAX_LOG_BUFFER; type++) {
274 /* Make a copy of the state structure, inside GuC log buffer
275 * (which is uncached mapped), on the stack to avoid reading
276 * from it multiple times.
278 memcpy(&log_buf_state_local, log_buf_state,
279 sizeof(struct guc_log_buffer_state));
280 buffer_size = guc_get_log_buffer_size(type);
281 read_offset = log_buf_state_local.read_ptr;
282 write_offset = log_buf_state_local.sampled_write_ptr;
283 full_cnt = log_buf_state_local.buffer_full_cnt;
285 /* Bookkeeping stuff */
286 guc->log.flush_count[type] += log_buf_state_local.flush_to_file;
287 new_overflow = guc_check_log_buf_overflow(guc, type, full_cnt);
289 /* Update the state of shared log buffer */
290 log_buf_state->read_ptr = write_offset;
291 log_buf_state->flush_to_file = 0;
294 if (unlikely(!log_buf_snapshot_state))
297 /* First copy the state structure in snapshot buffer */
298 memcpy(log_buf_snapshot_state, &log_buf_state_local,
299 sizeof(struct guc_log_buffer_state));
301 /* The write pointer could have been updated by GuC firmware,
302 * after sending the flush interrupt to Host, for consistency
303 * set write pointer value to same value of sampled_write_ptr
304 * in the snapshot buffer.
306 log_buf_snapshot_state->write_ptr = write_offset;
307 log_buf_snapshot_state++;
309 /* Now copy the actual logs. */
310 if (unlikely(new_overflow)) {
311 /* copy the whole buffer in case of overflow */
313 write_offset = buffer_size;
314 } else if (unlikely((read_offset > buffer_size) ||
315 (write_offset > buffer_size))) {
316 DRM_ERROR("invalid log buffer state\n");
317 /* copy whole buffer as offsets are unreliable */
319 write_offset = buffer_size;
322 /* Just copy the newly written data */
323 if (read_offset > write_offset) {
324 i915_memcpy_from_wc(dst_data, src_data, write_offset);
325 bytes_to_copy = buffer_size - read_offset;
327 bytes_to_copy = write_offset - read_offset;
329 i915_memcpy_from_wc(dst_data + read_offset,
330 src_data + read_offset, bytes_to_copy);
332 src_data += buffer_size;
333 dst_data += buffer_size;
336 if (log_buf_snapshot_state)
337 guc_move_to_next_buf(guc);
339 /* Used rate limited to avoid deluge of messages, logs might be
340 * getting consumed by User at a slow rate.
342 DRM_ERROR_RATELIMITED("no sub-buffer to capture logs\n");
343 guc->log.capture_miss_count++;
347 static void capture_logs_work(struct work_struct *work)
349 struct intel_guc *guc =
350 container_of(work, struct intel_guc, log.runtime.flush_work);
352 guc_log_capture_logs(guc);
355 static bool guc_log_has_runtime(struct intel_guc *guc)
357 return guc->log.runtime.buf_addr != NULL;
360 static int guc_log_runtime_create(struct intel_guc *guc)
362 struct drm_i915_private *dev_priv = guc_to_i915(guc);
364 struct rchan *guc_log_relay_chan;
365 size_t n_subbufs, subbuf_size;
368 lockdep_assert_held(&dev_priv->drm.struct_mutex);
370 GEM_BUG_ON(guc_log_has_runtime(guc));
372 ret = i915_gem_object_set_to_wc_domain(guc->log.vma->obj, true);
376 /* Create a WC (Uncached for read) vmalloc mapping of log
377 * buffer pages, so that we can directly get the data
378 * (up-to-date) from memory.
380 vaddr = i915_gem_object_pin_map(guc->log.vma->obj, I915_MAP_WC);
382 DRM_ERROR("Couldn't map log buffer pages %d\n", ret);
383 return PTR_ERR(vaddr);
386 guc->log.runtime.buf_addr = vaddr;
388 /* Keep the size of sub buffers same as shared log buffer */
389 subbuf_size = guc->log.vma->obj->base.size;
391 /* Store up to 8 snapshots, which is large enough to buffer sufficient
392 * boot time logs and provides enough leeway to User, in terms of
393 * latency, for consuming the logs from relay. Also doesn't take
394 * up too much memory.
398 /* Create a relay channel, so that we have buffers for storing
399 * the GuC firmware logs, the channel will be linked with a file
400 * later on when debugfs is registered.
402 guc_log_relay_chan = relay_open(NULL, NULL, subbuf_size,
403 n_subbufs, &relay_callbacks, dev_priv);
404 if (!guc_log_relay_chan) {
405 DRM_ERROR("Couldn't create relay chan for GuC logging\n");
411 GEM_BUG_ON(guc_log_relay_chan->subbuf_size < subbuf_size);
412 guc->log.runtime.relay_chan = guc_log_relay_chan;
414 INIT_WORK(&guc->log.runtime.flush_work, capture_logs_work);
417 * GuC log buffer flush work item has to do register access to
418 * send the ack to GuC and this work item, if not synced before
419 * suspend, can potentially get executed after the GFX device is
421 * By marking the WQ as freezable, we don't have to bother about
422 * flushing of this work item from the suspend hooks, the pending
423 * work item if any will be either executed before the suspend
424 * or scheduled later on resume. This way the handling of work
425 * item can be kept same between system suspend & rpm suspend.
427 guc->log.runtime.flush_wq = alloc_ordered_workqueue("i915-guc_log",
428 WQ_HIGHPRI | WQ_FREEZABLE);
429 if (!guc->log.runtime.flush_wq) {
430 DRM_ERROR("Couldn't allocate the wq for GuC logging\n");
438 relay_close(guc->log.runtime.relay_chan);
440 i915_gem_object_unpin_map(guc->log.vma->obj);
441 guc->log.runtime.buf_addr = NULL;
445 static void guc_log_runtime_destroy(struct intel_guc *guc)
448 * It's possible that the runtime stuff was never allocated because
449 * guc_log_level was < 0 at the time
451 if (!guc_log_has_runtime(guc))
454 destroy_workqueue(guc->log.runtime.flush_wq);
455 relay_close(guc->log.runtime.relay_chan);
456 i915_gem_object_unpin_map(guc->log.vma->obj);
457 guc->log.runtime.buf_addr = NULL;
460 static int guc_log_late_setup(struct intel_guc *guc)
462 struct drm_i915_private *dev_priv = guc_to_i915(guc);
465 lockdep_assert_held(&dev_priv->drm.struct_mutex);
467 if (!guc_log_has_runtime(guc)) {
468 /* If log_level was set as -1 at boot time, then setup needed to
469 * handle log buffer flush interrupts would not have been done yet,
472 ret = guc_log_runtime_create(guc);
477 ret = guc_log_relay_file_create(guc);
484 guc_log_runtime_destroy(guc);
486 /* logging will remain off */
487 i915_modparams.guc_log_level = -1;
491 static void guc_log_capture_logs(struct intel_guc *guc)
493 struct drm_i915_private *dev_priv = guc_to_i915(guc);
495 guc_read_update_log_buffer(guc);
497 /* Generally device is expected to be active only at this
498 * time, so get/put should be really quick.
500 intel_runtime_pm_get(dev_priv);
501 guc_log_flush_complete(guc);
502 intel_runtime_pm_put(dev_priv);
505 static void guc_flush_logs(struct intel_guc *guc)
507 struct drm_i915_private *dev_priv = guc_to_i915(guc);
509 if (!i915_modparams.enable_guc_submission ||
510 (i915_modparams.guc_log_level < 0))
513 /* First disable the interrupts, will be renabled afterwards */
514 gen9_disable_guc_interrupts(dev_priv);
516 /* Before initiating the forceful flush, wait for any pending/ongoing
517 * flush to complete otherwise forceful flush may not actually happen.
519 flush_work(&guc->log.runtime.flush_work);
521 /* Ask GuC to update the log buffer state */
524 /* GuC would have updated log buffer by now, so capture it */
525 guc_log_capture_logs(guc);
529 int intel_guc_log_create(struct intel_guc *guc)
531 struct i915_vma *vma;
532 unsigned long offset;
537 GEM_BUG_ON(guc->log.vma);
539 if (i915_modparams.guc_log_level > GUC_LOG_VERBOSITY_MAX)
540 i915_modparams.guc_log_level = GUC_LOG_VERBOSITY_MAX;
542 /* The first page is to save log buffer state. Allocate one
543 * extra page for others in case for overlap */
544 size = (1 + GUC_LOG_DPC_PAGES + 1 +
545 GUC_LOG_ISR_PAGES + 1 +
546 GUC_LOG_CRASH_PAGES + 1) << PAGE_SHIFT;
548 /* We require SSE 4.1 for fast reads from the GuC log buffer and
549 * it should be present on the chipsets supporting GuC based
552 if (WARN_ON(!i915_has_memcpy_from_wc())) {
557 vma = intel_guc_allocate_vma(guc, size);
566 if (i915.guc_log_level >= 0) {
567 ret = guc_log_runtime_create(guc);
573 /* each allocated unit is a page */
574 flags = GUC_LOG_VALID | GUC_LOG_NOTIFY_ON_HALF_FULL |
575 (GUC_LOG_DPC_PAGES << GUC_LOG_DPC_SHIFT) |
576 (GUC_LOG_ISR_PAGES << GUC_LOG_ISR_SHIFT) |
577 (GUC_LOG_CRASH_PAGES << GUC_LOG_CRASH_SHIFT);
579 offset = guc_ggtt_offset(vma) >> PAGE_SHIFT; /* in pages */
580 guc->log.flags = (offset << GUC_LOG_BUF_ADDR_SHIFT) | flags;
586 i915_vma_unpin_and_release(&guc->log.vma);
589 /* logging will be off */
590 i915_modparams.guc_log_level = -1;
594 void intel_guc_log_destroy(struct intel_guc *guc)
597 guc_log_runtime_destroy(guc);
599 i915_vma_unpin_and_release(&guc->log.vma);
603 int i915_guc_log_control(struct drm_i915_private *dev_priv, u64 control_val)
605 struct intel_guc *guc = &dev_priv->guc;
607 union guc_log_control log_param;
610 log_param.value = control_val;
612 if (log_param.verbosity < GUC_LOG_VERBOSITY_MIN ||
613 log_param.verbosity > GUC_LOG_VERBOSITY_MAX)
616 /* This combination doesn't make sense & won't have any effect */
617 if (!log_param.logging_enabled && (i915_modparams.guc_log_level < 0))
620 ret = guc_log_control(guc, log_param.value);
622 DRM_DEBUG_DRIVER("guc_logging_control action failed %d\n", ret);
626 if (log_param.logging_enabled) {
627 i915_modparams.guc_log_level = log_param.verbosity;
629 /* If log_level was set as -1 at boot time, then the relay channel file
630 * wouldn't have been created by now and interrupts also would not have
631 * been enabled. Try again now, just in case.
633 ret = guc_log_late_setup(guc);
635 DRM_DEBUG_DRIVER("GuC log late setup failed %d\n", ret);
639 /* GuC logging is currently the only user of Guc2Host interrupts */
640 gen9_enable_guc_interrupts(dev_priv);
642 /* Once logging is disabled, GuC won't generate logs & send an
643 * interrupt. But there could be some data in the log buffer
644 * which is yet to be captured. So request GuC to update the log
645 * buffer state and then collect the left over logs.
649 /* As logging is disabled, update log level to reflect that */
650 i915_modparams.guc_log_level = -1;
657 void i915_guc_log_register(struct drm_i915_private *dev_priv)
659 if (!i915_modparams.enable_guc_submission ||
660 (i915_modparams.guc_log_level < 0))
663 mutex_lock(&dev_priv->drm.struct_mutex);
665 guc_log_late_setup(&dev_priv->guc);
667 mutex_unlock(&dev_priv->drm.struct_mutex);
670 void i915_guc_log_unregister(struct drm_i915_private *dev_priv)
672 if (!i915_modparams.enable_guc_submission)
675 mutex_lock(&dev_priv->drm.struct_mutex);
676 /* GuC logging is currently the only user of Guc2Host interrupts */
677 gen9_disable_guc_interrupts(dev_priv);
679 guc_log_runtime_destroy(&dev_priv->guc);
681 mutex_unlock(&dev_priv->drm.struct_mutex);