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25 #include <linux/debugfs.h>
26 #include <linux/relay.h>
28 #include "intel_guc_log.h"
31 static void guc_log_capture_logs(struct intel_guc *guc);
34 * DOC: GuC firmware log
36 * Firmware log is enabled by setting i915.guc_log_level to non-negative level.
37 * Log data is printed out via reading debugfs i915_guc_log_dump. Reading from
38 * i915_guc_load_status will print out firmware loading status and scratch
43 static int guc_log_flush_complete(struct intel_guc *guc)
46 INTEL_GUC_ACTION_LOG_BUFFER_FILE_FLUSH_COMPLETE
49 return intel_guc_send(guc, action, ARRAY_SIZE(action));
52 static int guc_log_flush(struct intel_guc *guc)
55 INTEL_GUC_ACTION_FORCE_LOG_BUFFER_FLUSH,
59 return intel_guc_send(guc, action, ARRAY_SIZE(action));
62 static int guc_log_control(struct intel_guc *guc, u32 control_val)
65 INTEL_GUC_ACTION_UK_LOG_ENABLE_LOGGING,
69 return intel_guc_send(guc, action, ARRAY_SIZE(action));
73 * Sub buffer switch callback. Called whenever relay has to switch to a new
74 * sub buffer, relay stays on the same sub buffer if 0 is returned.
76 static int subbuf_start_callback(struct rchan_buf *buf,
81 /* Use no-overwrite mode by default, where relay will stop accepting
82 * new data if there are no empty sub buffers left.
83 * There is no strict synchronization enforced by relay between Consumer
84 * and Producer. In overwrite mode, there is a possibility of getting
85 * inconsistent/garbled data, the producer could be writing on to the
86 * same sub buffer from which Consumer is reading. This can't be avoided
87 * unless Consumer is fast enough and can always run in tandem with
90 if (relay_buf_full(buf))
97 * file_create() callback. Creates relay file in debugfs.
99 static struct dentry *create_buf_file_callback(const char *filename,
100 struct dentry *parent,
102 struct rchan_buf *buf,
105 struct dentry *buf_file;
107 /* This to enable the use of a single buffer for the relay channel and
108 * correspondingly have a single file exposed to User, through which
109 * it can collect the logs in order without any post-processing.
110 * Need to set 'is_global' even if parent is NULL for early logging.
117 /* Not using the channel filename passed as an argument, since for each
118 * channel relay appends the corresponding CPU number to the filename
119 * passed in relay_open(). This should be fine as relay just needs a
120 * dentry of the file associated with the channel buffer and that file's
121 * name need not be same as the filename passed as an argument.
123 buf_file = debugfs_create_file("guc_log", mode,
124 parent, buf, &relay_file_operations);
129 * file_remove() default callback. Removes relay file in debugfs.
131 static int remove_buf_file_callback(struct dentry *dentry)
133 debugfs_remove(dentry);
137 /* relay channel callbacks */
138 static struct rchan_callbacks relay_callbacks = {
139 .subbuf_start = subbuf_start_callback,
140 .create_buf_file = create_buf_file_callback,
141 .remove_buf_file = remove_buf_file_callback,
144 static int guc_log_relay_file_create(struct intel_guc *guc)
146 struct drm_i915_private *dev_priv = guc_to_i915(guc);
147 struct dentry *log_dir;
150 if (i915_modparams.guc_log_level < 0)
153 /* For now create the log file in /sys/kernel/debug/dri/0 dir */
154 log_dir = dev_priv->drm.primary->debugfs_root;
156 /* If /sys/kernel/debug/dri/0 location do not exist, then debugfs is
157 * not mounted and so can't create the relay file.
158 * The relay API seems to fit well with debugfs only, for availing relay
159 * there are 3 requirements which can be met for debugfs file only in a
160 * straightforward/clean manner :-
161 * i) Need the associated dentry pointer of the file, while opening the
163 * ii) Should be able to use 'relay_file_operations' fops for the file.
164 * iii) Set the 'i_private' field of file's inode to the pointer of
165 * relay channel buffer.
168 DRM_ERROR("Debugfs dir not available yet for GuC log file\n");
172 ret = relay_late_setup_files(guc->log.runtime.relay_chan, "guc_log", log_dir);
173 if (ret < 0 && ret != -EEXIST) {
174 DRM_ERROR("Couldn't associate relay chan with file %d\n", ret);
181 static void guc_move_to_next_buf(struct intel_guc *guc)
183 /* Make sure the updates made in the sub buffer are visible when
184 * Consumer sees the following update to offset inside the sub buffer.
188 /* All data has been written, so now move the offset of sub buffer. */
189 relay_reserve(guc->log.runtime.relay_chan, guc->log.vma->obj->base.size);
191 /* Switch to the next sub buffer */
192 relay_flush(guc->log.runtime.relay_chan);
195 static void *guc_get_write_buffer(struct intel_guc *guc)
197 if (!guc->log.runtime.relay_chan)
200 /* Just get the base address of a new sub buffer and copy data into it
201 * ourselves. NULL will be returned in no-overwrite mode, if all sub
202 * buffers are full. Could have used the relay_write() to indirectly
203 * copy the data, but that would have been bit convoluted, as we need to
204 * write to only certain locations inside a sub buffer which cannot be
205 * done without using relay_reserve() along with relay_write(). So its
206 * better to use relay_reserve() alone.
208 return relay_reserve(guc->log.runtime.relay_chan, 0);
211 static bool guc_check_log_buf_overflow(struct intel_guc *guc,
212 enum guc_log_buffer_type type,
213 unsigned int full_cnt)
215 unsigned int prev_full_cnt = guc->log.prev_overflow_count[type];
216 bool overflow = false;
218 if (full_cnt != prev_full_cnt) {
221 guc->log.prev_overflow_count[type] = full_cnt;
222 guc->log.total_overflow_count[type] += full_cnt - prev_full_cnt;
224 if (full_cnt < prev_full_cnt) {
225 /* buffer_full_cnt is a 4 bit counter */
226 guc->log.total_overflow_count[type] += 16;
228 DRM_ERROR_RATELIMITED("GuC log buffer overflow\n");
234 static unsigned int guc_get_log_buffer_size(enum guc_log_buffer_type type)
237 case GUC_ISR_LOG_BUFFER:
238 return (GUC_LOG_ISR_PAGES + 1) * PAGE_SIZE;
239 case GUC_DPC_LOG_BUFFER:
240 return (GUC_LOG_DPC_PAGES + 1) * PAGE_SIZE;
241 case GUC_CRASH_DUMP_LOG_BUFFER:
242 return (GUC_LOG_CRASH_PAGES + 1) * PAGE_SIZE;
250 static void guc_read_update_log_buffer(struct intel_guc *guc)
252 unsigned int buffer_size, read_offset, write_offset, bytes_to_copy, full_cnt;
253 struct guc_log_buffer_state *log_buf_state, *log_buf_snapshot_state;
254 struct guc_log_buffer_state log_buf_state_local;
255 enum guc_log_buffer_type type;
256 void *src_data, *dst_data;
259 if (WARN_ON(!guc->log.runtime.buf_addr))
262 /* Get the pointer to shared GuC log buffer */
263 log_buf_state = src_data = guc->log.runtime.buf_addr;
265 /* Get the pointer to local buffer to store the logs */
266 log_buf_snapshot_state = dst_data = guc_get_write_buffer(guc);
268 /* Actual logs are present from the 2nd page */
269 src_data += PAGE_SIZE;
270 dst_data += PAGE_SIZE;
272 for (type = GUC_ISR_LOG_BUFFER; type < GUC_MAX_LOG_BUFFER; type++) {
273 /* Make a copy of the state structure, inside GuC log buffer
274 * (which is uncached mapped), on the stack to avoid reading
275 * from it multiple times.
277 memcpy(&log_buf_state_local, log_buf_state,
278 sizeof(struct guc_log_buffer_state));
279 buffer_size = guc_get_log_buffer_size(type);
280 read_offset = log_buf_state_local.read_ptr;
281 write_offset = log_buf_state_local.sampled_write_ptr;
282 full_cnt = log_buf_state_local.buffer_full_cnt;
284 /* Bookkeeping stuff */
285 guc->log.flush_count[type] += log_buf_state_local.flush_to_file;
286 new_overflow = guc_check_log_buf_overflow(guc, type, full_cnt);
288 /* Update the state of shared log buffer */
289 log_buf_state->read_ptr = write_offset;
290 log_buf_state->flush_to_file = 0;
293 if (unlikely(!log_buf_snapshot_state))
296 /* First copy the state structure in snapshot buffer */
297 memcpy(log_buf_snapshot_state, &log_buf_state_local,
298 sizeof(struct guc_log_buffer_state));
300 /* The write pointer could have been updated by GuC firmware,
301 * after sending the flush interrupt to Host, for consistency
302 * set write pointer value to same value of sampled_write_ptr
303 * in the snapshot buffer.
305 log_buf_snapshot_state->write_ptr = write_offset;
306 log_buf_snapshot_state++;
308 /* Now copy the actual logs. */
309 if (unlikely(new_overflow)) {
310 /* copy the whole buffer in case of overflow */
312 write_offset = buffer_size;
313 } else if (unlikely((read_offset > buffer_size) ||
314 (write_offset > buffer_size))) {
315 DRM_ERROR("invalid log buffer state\n");
316 /* copy whole buffer as offsets are unreliable */
318 write_offset = buffer_size;
321 /* Just copy the newly written data */
322 if (read_offset > write_offset) {
323 i915_memcpy_from_wc(dst_data, src_data, write_offset);
324 bytes_to_copy = buffer_size - read_offset;
326 bytes_to_copy = write_offset - read_offset;
328 i915_memcpy_from_wc(dst_data + read_offset,
329 src_data + read_offset, bytes_to_copy);
331 src_data += buffer_size;
332 dst_data += buffer_size;
335 if (log_buf_snapshot_state)
336 guc_move_to_next_buf(guc);
338 /* Used rate limited to avoid deluge of messages, logs might be
339 * getting consumed by User at a slow rate.
341 DRM_ERROR_RATELIMITED("no sub-buffer to capture logs\n");
342 guc->log.capture_miss_count++;
346 static void capture_logs_work(struct work_struct *work)
348 struct intel_guc *guc =
349 container_of(work, struct intel_guc, log.runtime.flush_work);
351 guc_log_capture_logs(guc);
354 static bool guc_log_has_runtime(struct intel_guc *guc)
356 return guc->log.runtime.buf_addr != NULL;
359 static int guc_log_runtime_create(struct intel_guc *guc)
361 struct drm_i915_private *dev_priv = guc_to_i915(guc);
363 struct rchan *guc_log_relay_chan;
364 size_t n_subbufs, subbuf_size;
367 lockdep_assert_held(&dev_priv->drm.struct_mutex);
369 GEM_BUG_ON(guc_log_has_runtime(guc));
371 ret = i915_gem_object_set_to_wc_domain(guc->log.vma->obj, true);
375 /* Create a WC (Uncached for read) vmalloc mapping of log
376 * buffer pages, so that we can directly get the data
377 * (up-to-date) from memory.
379 vaddr = i915_gem_object_pin_map(guc->log.vma->obj, I915_MAP_WC);
381 DRM_ERROR("Couldn't map log buffer pages %d\n", ret);
382 return PTR_ERR(vaddr);
385 guc->log.runtime.buf_addr = vaddr;
387 /* Keep the size of sub buffers same as shared log buffer */
388 subbuf_size = guc->log.vma->obj->base.size;
390 /* Store up to 8 snapshots, which is large enough to buffer sufficient
391 * boot time logs and provides enough leeway to User, in terms of
392 * latency, for consuming the logs from relay. Also doesn't take
393 * up too much memory.
397 /* Create a relay channel, so that we have buffers for storing
398 * the GuC firmware logs, the channel will be linked with a file
399 * later on when debugfs is registered.
401 guc_log_relay_chan = relay_open(NULL, NULL, subbuf_size,
402 n_subbufs, &relay_callbacks, dev_priv);
403 if (!guc_log_relay_chan) {
404 DRM_ERROR("Couldn't create relay chan for GuC logging\n");
410 GEM_BUG_ON(guc_log_relay_chan->subbuf_size < subbuf_size);
411 guc->log.runtime.relay_chan = guc_log_relay_chan;
413 INIT_WORK(&guc->log.runtime.flush_work, capture_logs_work);
416 * GuC log buffer flush work item has to do register access to
417 * send the ack to GuC and this work item, if not synced before
418 * suspend, can potentially get executed after the GFX device is
420 * By marking the WQ as freezable, we don't have to bother about
421 * flushing of this work item from the suspend hooks, the pending
422 * work item if any will be either executed before the suspend
423 * or scheduled later on resume. This way the handling of work
424 * item can be kept same between system suspend & rpm suspend.
426 guc->log.runtime.flush_wq = alloc_ordered_workqueue("i915-guc_log",
427 WQ_HIGHPRI | WQ_FREEZABLE);
428 if (!guc->log.runtime.flush_wq) {
429 DRM_ERROR("Couldn't allocate the wq for GuC logging\n");
437 relay_close(guc->log.runtime.relay_chan);
439 i915_gem_object_unpin_map(guc->log.vma->obj);
440 guc->log.runtime.buf_addr = NULL;
444 static void guc_log_runtime_destroy(struct intel_guc *guc)
447 * It's possible that the runtime stuff was never allocated because
448 * guc_log_level was < 0 at the time
450 if (!guc_log_has_runtime(guc))
453 destroy_workqueue(guc->log.runtime.flush_wq);
454 relay_close(guc->log.runtime.relay_chan);
455 i915_gem_object_unpin_map(guc->log.vma->obj);
456 guc->log.runtime.buf_addr = NULL;
459 static int guc_log_late_setup(struct intel_guc *guc)
461 struct drm_i915_private *dev_priv = guc_to_i915(guc);
464 lockdep_assert_held(&dev_priv->drm.struct_mutex);
466 if (!guc_log_has_runtime(guc)) {
467 /* If log_level was set as -1 at boot time, then setup needed to
468 * handle log buffer flush interrupts would not have been done yet,
471 ret = guc_log_runtime_create(guc);
476 ret = guc_log_relay_file_create(guc);
483 guc_log_runtime_destroy(guc);
485 /* logging will remain off */
486 i915_modparams.guc_log_level = -1;
490 static void guc_log_capture_logs(struct intel_guc *guc)
492 struct drm_i915_private *dev_priv = guc_to_i915(guc);
494 guc_read_update_log_buffer(guc);
496 /* Generally device is expected to be active only at this
497 * time, so get/put should be really quick.
499 intel_runtime_pm_get(dev_priv);
500 guc_log_flush_complete(guc);
501 intel_runtime_pm_put(dev_priv);
504 static void guc_flush_logs(struct intel_guc *guc)
506 struct drm_i915_private *dev_priv = guc_to_i915(guc);
508 if (!i915_modparams.enable_guc_submission ||
509 (i915_modparams.guc_log_level < 0))
512 /* First disable the interrupts, will be renabled afterwards */
513 gen9_disable_guc_interrupts(dev_priv);
515 /* Before initiating the forceful flush, wait for any pending/ongoing
516 * flush to complete otherwise forceful flush may not actually happen.
518 flush_work(&guc->log.runtime.flush_work);
520 /* Ask GuC to update the log buffer state */
523 /* GuC would have updated log buffer by now, so capture it */
524 guc_log_capture_logs(guc);
527 int intel_guc_log_create(struct intel_guc *guc)
529 struct i915_vma *vma;
530 unsigned long offset;
535 GEM_BUG_ON(guc->log.vma);
537 if (i915_modparams.guc_log_level > GUC_LOG_VERBOSITY_MAX)
538 i915_modparams.guc_log_level = GUC_LOG_VERBOSITY_MAX;
540 /* The first page is to save log buffer state. Allocate one
541 * extra page for others in case for overlap */
542 size = (1 + GUC_LOG_DPC_PAGES + 1 +
543 GUC_LOG_ISR_PAGES + 1 +
544 GUC_LOG_CRASH_PAGES + 1) << PAGE_SHIFT;
546 /* We require SSE 4.1 for fast reads from the GuC log buffer and
547 * it should be present on the chipsets supporting GuC based
550 if (WARN_ON(!i915_has_memcpy_from_wc())) {
555 vma = intel_guc_allocate_vma(guc, size);
563 if (i915_modparams.guc_log_level >= 0) {
564 ret = guc_log_runtime_create(guc);
569 /* each allocated unit is a page */
570 flags = GUC_LOG_VALID | GUC_LOG_NOTIFY_ON_HALF_FULL |
571 (GUC_LOG_DPC_PAGES << GUC_LOG_DPC_SHIFT) |
572 (GUC_LOG_ISR_PAGES << GUC_LOG_ISR_SHIFT) |
573 (GUC_LOG_CRASH_PAGES << GUC_LOG_CRASH_SHIFT);
575 offset = guc_ggtt_offset(vma) >> PAGE_SHIFT; /* in pages */
576 guc->log.flags = (offset << GUC_LOG_BUF_ADDR_SHIFT) | flags;
581 i915_vma_unpin_and_release(&guc->log.vma);
583 /* logging will be off */
584 i915_modparams.guc_log_level = -1;
588 void intel_guc_log_destroy(struct intel_guc *guc)
590 guc_log_runtime_destroy(guc);
591 i915_vma_unpin_and_release(&guc->log.vma);
594 int i915_guc_log_control(struct drm_i915_private *dev_priv, u64 control_val)
596 struct intel_guc *guc = &dev_priv->guc;
598 union guc_log_control log_param;
601 log_param.value = control_val;
603 if (log_param.verbosity < GUC_LOG_VERBOSITY_MIN ||
604 log_param.verbosity > GUC_LOG_VERBOSITY_MAX)
607 /* This combination doesn't make sense & won't have any effect */
608 if (!log_param.logging_enabled && (i915_modparams.guc_log_level < 0))
611 ret = guc_log_control(guc, log_param.value);
613 DRM_DEBUG_DRIVER("guc_logging_control action failed %d\n", ret);
617 if (log_param.logging_enabled) {
618 i915_modparams.guc_log_level = log_param.verbosity;
620 /* If log_level was set as -1 at boot time, then the relay channel file
621 * wouldn't have been created by now and interrupts also would not have
622 * been enabled. Try again now, just in case.
624 ret = guc_log_late_setup(guc);
626 DRM_DEBUG_DRIVER("GuC log late setup failed %d\n", ret);
630 /* GuC logging is currently the only user of Guc2Host interrupts */
631 gen9_enable_guc_interrupts(dev_priv);
633 /* Once logging is disabled, GuC won't generate logs & send an
634 * interrupt. But there could be some data in the log buffer
635 * which is yet to be captured. So request GuC to update the log
636 * buffer state and then collect the left over logs.
640 /* As logging is disabled, update log level to reflect that */
641 i915_modparams.guc_log_level = -1;
647 void i915_guc_log_register(struct drm_i915_private *dev_priv)
649 if (!i915_modparams.enable_guc_submission ||
650 (i915_modparams.guc_log_level < 0))
653 mutex_lock(&dev_priv->drm.struct_mutex);
654 guc_log_late_setup(&dev_priv->guc);
655 mutex_unlock(&dev_priv->drm.struct_mutex);
658 void i915_guc_log_unregister(struct drm_i915_private *dev_priv)
660 if (!i915_modparams.enable_guc_submission)
663 mutex_lock(&dev_priv->drm.struct_mutex);
664 /* GuC logging is currently the only user of Guc2Host interrupts */
665 gen9_disable_guc_interrupts(dev_priv);
666 guc_log_runtime_destroy(&dev_priv->guc);
667 mutex_unlock(&dev_priv->drm.struct_mutex);