1 files changed, 658 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_guc_log.c b/drivers/gpu/drm/i915/intel_guc_log.c
new file mode 100644
index 000000000000..5c0f9a49da0e
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_guc_log.c
@@ -0,0 +1,658 @@
+/*
+ * Copyright © 2014-2017 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+#include <linux/debugfs.h>
+#include <linux/relay.h>
+#include "i915_drv.h"
+
+static void guc_log_capture_logs(struct intel_guc *guc);
+
+/**
+ * DOC: GuC firmware log
+ *
+ * Firmware log is enabled by setting i915.guc_log_level to non-negative level.
+ * Log data is printed out via reading debugfs i915_guc_log_dump. Reading from
+ * i915_guc_load_status will print out firmware loading status and scratch
+ * registers value.
+ *
+ */
+
+static int guc_log_flush_complete(struct intel_guc *guc)
+{
+	u32 action[] = {
+		INTEL_GUC_ACTION_LOG_BUFFER_FILE_FLUSH_COMPLETE
+	};
+
+	return intel_guc_send(guc, action, ARRAY_SIZE(action));
+}
+
+static int guc_log_flush(struct intel_guc *guc)
+{
+	u32 action[] = {
+		INTEL_GUC_ACTION_FORCE_LOG_BUFFER_FLUSH,
+		0
+	};
+
+	return intel_guc_send(guc, action, ARRAY_SIZE(action));
+}
+
+static int guc_log_control(struct intel_guc *guc, u32 control_val)
+{
+	u32 action[] = {
+		INTEL_GUC_ACTION_UK_LOG_ENABLE_LOGGING,
+		control_val
+	};
+
+	return intel_guc_send(guc, action, ARRAY_SIZE(action));
+}
+
+
+/*
+ * Sub buffer switch callback. Called whenever relay has to switch to a new
+ * sub buffer, relay stays on the same sub buffer if 0 is returned.
+ */
+static int subbuf_start_callback(struct rchan_buf *buf,
+				 void *subbuf,
+				 void *prev_subbuf,
+				 size_t prev_padding)
+{
+	/* Use no-overwrite mode by default, where relay will stop accepting
+	 * new data if there are no empty sub buffers left.
+	 * There is no strict synchronization enforced by relay between Consumer
+	 * and Producer. In overwrite mode, there is a possibility of getting
+	 * inconsistent/garbled data, the producer could be writing on to the
+	 * same sub buffer from which Consumer is reading. This can't be avoided
+	 * unless Consumer is fast enough and can always run in tandem with
+	 * Producer.
+	 */
+	if (relay_buf_full(buf))
+		return 0;
+
+	return 1;
+}
+
+/*
+ * file_create() callback. Creates relay file in debugfs.
+ */
+static struct dentry *create_buf_file_callback(const char *filename,
+					       struct dentry *parent,
+					       umode_t mode,
+					       struct rchan_buf *buf,
+					       int *is_global)
+{
+	struct dentry *buf_file;
+
+	/* This to enable the use of a single buffer for the relay channel and
+	 * correspondingly have a single file exposed to User, through which
+	 * it can collect the logs in order without any post-processing.
+	 * Need to set 'is_global' even if parent is NULL for early logging.
+	 */
+	*is_global = 1;
+
+	if (!parent)
+		return NULL;
+
+	/* Not using the channel filename passed as an argument, since for each
+	 * channel relay appends the corresponding CPU number to the filename
+	 * passed in relay_open(). This should be fine as relay just needs a
+	 * dentry of the file associated with the channel buffer and that file's
+	 * name need not be same as the filename passed as an argument.
+	 */
+	buf_file = debugfs_create_file("guc_log", mode,
+				       parent, buf, &relay_file_operations);
+	return buf_file;
+}
+
+/*
+ * file_remove() default callback. Removes relay file in debugfs.
+ */
+static int remove_buf_file_callback(struct dentry *dentry)
+{
+	debugfs_remove(dentry);
+	return 0;
+}
+
+/* relay channel callbacks */
+static struct rchan_callbacks relay_callbacks = {
+	.subbuf_start = subbuf_start_callback,
+	.create_buf_file = create_buf_file_callback,
+	.remove_buf_file = remove_buf_file_callback,
+};
+
+static void guc_log_remove_relay_file(struct intel_guc *guc)
+{
+	relay_close(guc->log.relay_chan);
+}
+
+static int guc_log_create_relay_channel(struct intel_guc *guc)
+{
+	struct drm_i915_private *dev_priv = guc_to_i915(guc);
+	struct rchan *guc_log_relay_chan;
+	size_t n_subbufs, subbuf_size;
+
+	/* Keep the size of sub buffers same as shared log buffer */
+	subbuf_size = guc->log.vma->obj->base.size;
+
+	/* Store up to 8 snapshots, which is large enough to buffer sufficient
+	 * boot time logs and provides enough leeway to User, in terms of
+	 * latency, for consuming the logs from relay. Also doesn't take
+	 * up too much memory.
+	 */
+	n_subbufs = 8;
+
+	guc_log_relay_chan = relay_open(NULL, NULL, subbuf_size,
+					n_subbufs, &relay_callbacks, dev_priv);
+	if (!guc_log_relay_chan) {
+		DRM_ERROR("Couldn't create relay chan for GuC logging\n");
+		return -ENOMEM;
+	}
+
+	GEM_BUG_ON(guc_log_relay_chan->subbuf_size < subbuf_size);
+	guc->log.relay_chan = guc_log_relay_chan;
+	return 0;
+}
+
+static int guc_log_create_relay_file(struct intel_guc *guc)
+{
+	struct drm_i915_private *dev_priv = guc_to_i915(guc);
+	struct dentry *log_dir;
+	int ret;
+
+	/* For now create the log file in /sys/kernel/debug/dri/0 dir */
+	log_dir = dev_priv->drm.primary->debugfs_root;
+
+	/* If /sys/kernel/debug/dri/0 location do not exist, then debugfs is
+	 * not mounted and so can't create the relay file.
+	 * The relay API seems to fit well with debugfs only, for availing relay
+	 * there are 3 requirements which can be met for debugfs file only in a
+	 * straightforward/clean manner :-
+	 * i)   Need the associated dentry pointer of the file, while opening the
+	 *      relay channel.
+	 * ii)  Should be able to use 'relay_file_operations' fops for the file.
+	 * iii) Set the 'i_private' field of file's inode to the pointer of
+	 *	relay channel buffer.
+	 */
+	if (!log_dir) {
+		DRM_ERROR("Debugfs dir not available yet for GuC log file\n");
+		return -ENODEV;
+	}
+
+	ret = relay_late_setup_files(guc->log.relay_chan, "guc_log", log_dir);
+	if (ret) {
+		DRM_ERROR("Couldn't associate relay chan with file %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void guc_move_to_next_buf(struct intel_guc *guc)
+{
+	/* Make sure the updates made in the sub buffer are visible when
+	 * Consumer sees the following update to offset inside the sub buffer.
+	 */
+	smp_wmb();
+
+	/* All data has been written, so now move the offset of sub buffer. */
+	relay_reserve(guc->log.relay_chan, guc->log.vma->obj->base.size);
+
+	/* Switch to the next sub buffer */
+	relay_flush(guc->log.relay_chan);
+}
+
+static void *guc_get_write_buffer(struct intel_guc *guc)
+{
+	if (!guc->log.relay_chan)
+		return NULL;
+
+	/* Just get the base address of a new sub buffer and copy data into it
+	 * ourselves. NULL will be returned in no-overwrite mode, if all sub
+	 * buffers are full. Could have used the relay_write() to indirectly
+	 * copy the data, but that would have been bit convoluted, as we need to
+	 * write to only certain locations inside a sub buffer which cannot be
+	 * done without using relay_reserve() along with relay_write(). So its
+	 * better to use relay_reserve() alone.
+	 */
+	return relay_reserve(guc->log.relay_chan, 0);
+}
+
+static bool guc_check_log_buf_overflow(struct intel_guc *guc,
+				       enum guc_log_buffer_type type,
+				       unsigned int full_cnt)
+{
+	unsigned int prev_full_cnt = guc->log.prev_overflow_count[type];
+	bool overflow = false;
+
+	if (full_cnt != prev_full_cnt) {
+		overflow = true;
+
+		guc->log.prev_overflow_count[type] = full_cnt;
+		guc->log.total_overflow_count[type] += full_cnt - prev_full_cnt;
+
+		if (full_cnt < prev_full_cnt) {
+			/* buffer_full_cnt is a 4 bit counter */
+			guc->log.total_overflow_count[type] += 16;
+		}
+		DRM_ERROR_RATELIMITED("GuC log buffer overflow\n");
+	}
+
+	return overflow;
+}
+
+static unsigned int guc_get_log_buffer_size(enum guc_log_buffer_type type)
+{
+	switch (type) {
+	case GUC_ISR_LOG_BUFFER:
+		return (GUC_LOG_ISR_PAGES + 1) * PAGE_SIZE;
+	case GUC_DPC_LOG_BUFFER:
+		return (GUC_LOG_DPC_PAGES + 1) * PAGE_SIZE;
+	case GUC_CRASH_DUMP_LOG_BUFFER:
+		return (GUC_LOG_CRASH_PAGES + 1) * PAGE_SIZE;
+	default:
+		MISSING_CASE(type);
+	}
+
+	return 0;
+}
+
+static void guc_read_update_log_buffer(struct intel_guc *guc)
+{
+	unsigned int buffer_size, read_offset, write_offset, bytes_to_copy, full_cnt;
+	struct guc_log_buffer_state *log_buf_state, *log_buf_snapshot_state;
+	struct guc_log_buffer_state log_buf_state_local;
+	enum guc_log_buffer_type type;
+	void *src_data, *dst_data;
+	bool new_overflow;
+
+	if (WARN_ON(!guc->log.buf_addr))
+		return;
+
+	/* Get the pointer to shared GuC log buffer */
+	log_buf_state = src_data = guc->log.buf_addr;
+
+	/* Get the pointer to local buffer to store the logs */
+	log_buf_snapshot_state = dst_data = guc_get_write_buffer(guc);
+
+	/* Actual logs are present from the 2nd page */
+	src_data += PAGE_SIZE;
+	dst_data += PAGE_SIZE;
+
+	for (type = GUC_ISR_LOG_BUFFER; type < GUC_MAX_LOG_BUFFER; type++) {
+		/* Make a copy of the state structure, inside GuC log buffer
+		 * (which is uncached mapped), on the stack to avoid reading
+		 * from it multiple times.
+		 */
+		memcpy(&log_buf_state_local, log_buf_state,
+		       sizeof(struct guc_log_buffer_state));
+		buffer_size = guc_get_log_buffer_size(type);
+		read_offset = log_buf_state_local.read_ptr;
+		write_offset = log_buf_state_local.sampled_write_ptr;
+		full_cnt = log_buf_state_local.buffer_full_cnt;
+
+		/* Bookkeeping stuff */
+		guc->log.flush_count[type] += log_buf_state_local.flush_to_file;
+		new_overflow = guc_check_log_buf_overflow(guc, type, full_cnt);
+
+		/* Update the state of shared log buffer */
+		log_buf_state->read_ptr = write_offset;
+		log_buf_state->flush_to_file = 0;
+		log_buf_state++;
+
+		if (unlikely(!log_buf_snapshot_state))
+			continue;
+
+		/* First copy the state structure in snapshot buffer */
+		memcpy(log_buf_snapshot_state, &log_buf_state_local,
+		       sizeof(struct guc_log_buffer_state));
+
+		/* The write pointer could have been updated by GuC firmware,
+		 * after sending the flush interrupt to Host, for consistency
+		 * set write pointer value to same value of sampled_write_ptr
+		 * in the snapshot buffer.
+		 */
+		log_buf_snapshot_state->write_ptr = write_offset;
+		log_buf_snapshot_state++;
+
+		/* Now copy the actual logs. */
+		if (unlikely(new_overflow)) {
+			/* copy the whole buffer in case of overflow */
+			read_offset = 0;
+			write_offset = buffer_size;
+		} else if (unlikely((read_offset > buffer_size) ||
+				    (write_offset > buffer_size))) {
+			DRM_ERROR("invalid log buffer state\n");
+			/* copy whole buffer as offsets are unreliable */
+			read_offset = 0;
+			write_offset = buffer_size;
+		}
+
+		/* Just copy the newly written data */
+		if (read_offset > write_offset) {
+			i915_memcpy_from_wc(dst_data, src_data, write_offset);
+			bytes_to_copy = buffer_size - read_offset;
+		} else {
+			bytes_to_copy = write_offset - read_offset;
+		}
+		i915_memcpy_from_wc(dst_data + read_offset,
+				    src_data + read_offset, bytes_to_copy);
+
+		src_data += buffer_size;
+		dst_data += buffer_size;
+	}
+
+	if (log_buf_snapshot_state)
+		guc_move_to_next_buf(guc);
+	else {
+		/* Used rate limited to avoid deluge of messages, logs might be
+		 * getting consumed by User at a slow rate.
+		 */
+		DRM_ERROR_RATELIMITED("no sub-buffer to capture logs\n");
+		guc->log.capture_miss_count++;
+	}
+}
+
+static void guc_log_cleanup(struct intel_guc *guc)
+{
+	struct drm_i915_private *dev_priv = guc_to_i915(guc);
+
+	lockdep_assert_held(&dev_priv->drm.struct_mutex);
+
+	/* First disable the flush interrupt */
+	gen9_disable_guc_interrupts(dev_priv);
+
+	if (guc->log.flush_wq)
+		destroy_workqueue(guc->log.flush_wq);
+
+	guc->log.flush_wq = NULL;
+
+	if (guc->log.relay_chan)
+		guc_log_remove_relay_file(guc);
+
+	guc->log.relay_chan = NULL;
+
+	if (guc->log.buf_addr)
+		i915_gem_object_unpin_map(guc->log.vma->obj);
+
+	guc->log.buf_addr = NULL;
+}
+
+static void capture_logs_work(struct work_struct *work)
+{
+	struct intel_guc *guc =
+		container_of(work, struct intel_guc, log.flush_work);
+
+	guc_log_capture_logs(guc);
+}
+
+static int guc_log_create_extras(struct intel_guc *guc)
+{
+	struct drm_i915_private *dev_priv = guc_to_i915(guc);
+	void *vaddr;
+	int ret;
+
+	lockdep_assert_held(&dev_priv->drm.struct_mutex);
+
+	/* Nothing to do */
+	if (i915.guc_log_level < 0)
+		return 0;
+
+	if (!guc->log.buf_addr) {
+		/* Create a WC (Uncached for read) vmalloc mapping of log
+		 * buffer pages, so that we can directly get the data
+		 * (up-to-date) from memory.
+		 */
+		vaddr = i915_gem_object_pin_map(guc->log.vma->obj, I915_MAP_WC);
+		if (IS_ERR(vaddr)) {
+			ret = PTR_ERR(vaddr);
+			DRM_ERROR("Couldn't map log buffer pages %d\n", ret);
+			return ret;
+		}
+
+		guc->log.buf_addr = vaddr;
+	}
+
+	if (!guc->log.relay_chan) {
+		/* Create a relay channel, so that we have buffers for storing
+		 * the GuC firmware logs, the channel will be linked with a file
+		 * later on when debugfs is registered.
+		 */
+		ret = guc_log_create_relay_channel(guc);
+		if (ret)
+			return ret;
+	}
+
+	if (!guc->log.flush_wq) {
+		INIT_WORK(&guc->log.flush_work, capture_logs_work);
+
+		 /*
+		 * GuC log buffer flush work item has to do register access to
+		 * send the ack to GuC and this work item, if not synced before
+		 * suspend, can potentially get executed after the GFX device is
+		 * suspended.
+		 * By marking the WQ as freezable, we don't have to bother about
+		 * flushing of this work item from the suspend hooks, the pending
+		 * work item if any will be either executed before the suspend
+		 * or scheduled later on resume. This way the handling of work
+		 * item can be kept same between system suspend & rpm suspend.
+		 */
+		guc->log.flush_wq = alloc_ordered_workqueue("i915-guc_log",
+							    WQ_HIGHPRI | WQ_FREEZABLE);
+		if (guc->log.flush_wq == NULL) {
+			DRM_ERROR("Couldn't allocate the wq for GuC logging\n");
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+void intel_guc_log_create(struct intel_guc *guc)
+{
+	struct i915_vma *vma;
+	unsigned long offset;
+	uint32_t size, flags;
+
+	if (i915.guc_log_level > GUC_LOG_VERBOSITY_MAX)
+		i915.guc_log_level = GUC_LOG_VERBOSITY_MAX;
+
+	/* The first page is to save log buffer state. Allocate one
+	 * extra page for others in case for overlap */
+	size = (1 + GUC_LOG_DPC_PAGES + 1 +
+		GUC_LOG_ISR_PAGES + 1 +
+		GUC_LOG_CRASH_PAGES + 1) << PAGE_SHIFT;
+
+	vma = guc->log.vma;
+	if (!vma) {
+		/* We require SSE 4.1 for fast reads from the GuC log buffer and
+		 * it should be present on the chipsets supporting GuC based
+		 * submisssions.
+		 */
+		if (WARN_ON(!i915_has_memcpy_from_wc())) {
+			/* logging will not be enabled */
+			i915.guc_log_level = -1;
+			return;
+		}
+
+		vma = intel_guc_allocate_vma(guc, size);
+		if (IS_ERR(vma)) {
+			/* logging will be off */
+			i915.guc_log_level = -1;
+			return;
+		}
+
+		guc->log.vma = vma;
+
+		if (guc_log_create_extras(guc)) {
+			guc_log_cleanup(guc);
+			i915_vma_unpin_and_release(&guc->log.vma);
+			i915.guc_log_level = -1;
+			return;
+		}
+	}
+
+	/* each allocated unit is a page */
+	flags = GUC_LOG_VALID | GUC_LOG_NOTIFY_ON_HALF_FULL |
+		(GUC_LOG_DPC_PAGES << GUC_LOG_DPC_SHIFT) |
+		(GUC_LOG_ISR_PAGES << GUC_LOG_ISR_SHIFT) |
+		(GUC_LOG_CRASH_PAGES << GUC_LOG_CRASH_SHIFT);
+
+	offset = guc_ggtt_offset(vma) >> PAGE_SHIFT; /* in pages */
+	guc->log.flags = (offset << GUC_LOG_BUF_ADDR_SHIFT) | flags;
+}
+
+static int guc_log_late_setup(struct intel_guc *guc)
+{
+	struct drm_i915_private *dev_priv = guc_to_i915(guc);
+	int ret;
+
+	lockdep_assert_held(&dev_priv->drm.struct_mutex);
+
+	if (i915.guc_log_level < 0)
+		return -EINVAL;
+
+	/* If log_level was set as -1 at boot time, then setup needed to
+	 * handle log buffer flush interrupts would not have been done yet,
+	 * so do that now.
+	 */
+	ret = guc_log_create_extras(guc);
+	if (ret)
+		goto err;
+
+	ret = guc_log_create_relay_file(guc);
+	if (ret)
+		goto err;
+
+	return 0;
+err:
+	guc_log_cleanup(guc);
+	/* logging will remain off */
+	i915.guc_log_level = -1;
+	return ret;
+}
+
+static void guc_log_capture_logs(struct intel_guc *guc)
+{
+	struct drm_i915_private *dev_priv = guc_to_i915(guc);
+
+	guc_read_update_log_buffer(guc);
+
+	/* Generally device is expected to be active only at this
+	 * time, so get/put should be really quick.
+	 */
+	intel_runtime_pm_get(dev_priv);
+	guc_log_flush_complete(guc);
+	intel_runtime_pm_put(dev_priv);
+}
+
+static void guc_flush_logs(struct intel_guc *guc)
+{
+	struct drm_i915_private *dev_priv = guc_to_i915(guc);
+
+	if (!i915.enable_guc_submission || (i915.guc_log_level < 0))
+		return;
+
+	/* First disable the interrupts, will be renabled afterwards */
+	gen9_disable_guc_interrupts(dev_priv);
+
+	/* Before initiating the forceful flush, wait for any pending/ongoing
+	 * flush to complete otherwise forceful flush may not actually happen.
+	 */
+	flush_work(&guc->log.flush_work);
+
+	/* Ask GuC to update the log buffer state */
+	guc_log_flush(guc);
+
+	/* GuC would have updated log buffer by now, so capture it */
+	guc_log_capture_logs(guc);
+}
+
+int i915_guc_log_control(struct drm_i915_private *dev_priv, u64 control_val)
+{
+	struct intel_guc *guc = &dev_priv->guc;
+
+	union guc_log_control log_param;
+	int ret;
+
+	log_param.value = control_val;
+
+	if (log_param.verbosity < GUC_LOG_VERBOSITY_MIN ||
+	    log_param.verbosity > GUC_LOG_VERBOSITY_MAX)
+		return -EINVAL;
+
+	/* This combination doesn't make sense & won't have any effect */
+	if (!log_param.logging_enabled && (i915.guc_log_level < 0))
+		return 0;
+
+	ret = guc_log_control(guc, log_param.value);
+	if (ret < 0) {
+		DRM_DEBUG_DRIVER("guc_logging_control action failed %d\n", ret);
+		return ret;
+	}
+
+	i915.guc_log_level = log_param.verbosity;
+
+	/* If log_level was set as -1 at boot time, then the relay channel file
+	 * wouldn't have been created by now and interrupts also would not have
+	 * been enabled.
+	 */
+	if (!dev_priv->guc.log.relay_chan) {
+		ret = guc_log_late_setup(guc);
+		if (!ret)
+			gen9_enable_guc_interrupts(dev_priv);
+	} else if (!log_param.logging_enabled) {
+		/* Once logging is disabled, GuC won't generate logs & send an
+		 * interrupt. But there could be some data in the log buffer
+		 * which is yet to be captured. So request GuC to update the log
+		 * buffer state and then collect the left over logs.
+		 */
+		guc_flush_logs(guc);
+
+		/* As logging is disabled, update log level to reflect that */
+		i915.guc_log_level = -1;
+	} else {
+		/* In case interrupts were disabled, enable them now */
+		gen9_enable_guc_interrupts(dev_priv);
+	}
+
+	return ret;
+}
+
+void i915_guc_log_register(struct drm_i915_private *dev_priv)
+{
+	if (!i915.enable_guc_submission)
+		return;
+
+	mutex_lock(&dev_priv->drm.struct_mutex);
+	guc_log_late_setup(&dev_priv->guc);
+	mutex_unlock(&dev_priv->drm.struct_mutex);
+}
+
+void i915_guc_log_unregister(struct drm_i915_private *dev_priv)
+{
+	if (!i915.enable_guc_submission)
+		return;
+
+	mutex_lock(&dev_priv->drm.struct_mutex);
+	guc_log_cleanup(&dev_priv->guc);
+	mutex_unlock(&dev_priv->drm.struct_mutex);
+}