]> git.karo-electronics.de Git - karo-tx-linux.git/blobdiff - drivers/gpu/drm/i915/i915_guc_submission.c
drm/i915: Rearrange i915_wait_request() accounting with callers
[karo-tx-linux.git] / drivers / gpu / drm / i915 / i915_guc_submission.c
index 3106dcc06fe93d40361ce19428e5d40178c977fe..74235ea3950f24347728ba4d740640ab3186e1f1 100644 (file)
@@ -23,6 +23,8 @@
  */
 #include <linux/firmware.h>
 #include <linux/circ_buf.h>
+#include <linux/debugfs.h>
+#include <linux/relay.h>
 #include "i915_drv.h"
 #include "intel_guc.h"
 
@@ -85,6 +87,7 @@ static int host2guc_action(struct intel_guc *guc, u32 *data, u32 len)
        if (WARN_ON(len < 1 || len > 15))
                return -EINVAL;
 
+       mutex_lock(&guc->action_lock);
        intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);
 
        dev_priv->guc.action_count += 1;
@@ -123,6 +126,7 @@ static int host2guc_action(struct intel_guc *guc, u32 *data, u32 len)
        dev_priv->guc.action_status = status;
 
        intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
+       mutex_unlock(&guc->action_lock);
 
        return ret;
 }
@@ -170,6 +174,35 @@ static int host2guc_sample_forcewake(struct intel_guc *guc,
        return host2guc_action(guc, data, ARRAY_SIZE(data));
 }
 
+static int host2guc_logbuffer_flush_complete(struct intel_guc *guc)
+{
+       u32 data[1];
+
+       data[0] = HOST2GUC_ACTION_LOG_BUFFER_FILE_FLUSH_COMPLETE;
+
+       return host2guc_action(guc, data, 1);
+}
+
+static int host2guc_force_logbuffer_flush(struct intel_guc *guc)
+{
+       u32 data[2];
+
+       data[0] = HOST2GUC_ACTION_FORCE_LOG_BUFFER_FLUSH;
+       data[1] = 0;
+
+       return host2guc_action(guc, data, 2);
+}
+
+static int host2guc_logging_control(struct intel_guc *guc, u32 control_val)
+{
+       u32 data[2];
+
+       data[0] = HOST2GUC_ACTION_UK_LOG_ENABLE_LOGGING;
+       data[1] = control_val;
+
+       return host2guc_action(guc, data, 2);
+}
+
 /*
  * Initialise, update, or clear doorbell data shared with the GuC
  *
@@ -601,6 +634,7 @@ static int guc_ring_doorbell(struct i915_guc_client *gc)
  */
 static void i915_guc_submit(struct drm_i915_gem_request *rq)
 {
+       struct drm_i915_private *dev_priv = rq->i915;
        unsigned int engine_id = rq->engine->id;
        struct intel_guc *guc = &rq->i915->guc;
        struct i915_guc_client *client = guc->execbuf_client;
@@ -608,6 +642,11 @@ static void i915_guc_submit(struct drm_i915_gem_request *rq)
 
        spin_lock(&client->wq_lock);
        guc_wq_item_append(client, rq);
+
+       /* WA to flush out the pending GMADR writes to ring buffer. */
+       if (i915_vma_is_map_and_fenceable(rq->ring->vma))
+               POSTING_READ_FW(GUC_STATUS);
+
        b_ret = guc_ring_doorbell(client);
 
        client->submissions[engine_id] += 1;
@@ -847,15 +886,411 @@ err:
        return NULL;
 }
 
+/*
+ * 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_capture_logs_work(struct work_struct *work)
+{
+       struct drm_i915_private *dev_priv =
+               container_of(work, struct drm_i915_private, guc.log.flush_work);
+
+       i915_guc_capture_logs(dev_priv);
+}
+
+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 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, guc_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;
+}
+
 static void 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_MIN)
-               return;
-
        if (i915.guc_log_level > GUC_LOG_VERBOSITY_MAX)
                i915.guc_log_level = GUC_LOG_VERBOSITY_MAX;
 
@@ -865,8 +1300,18 @@ static void guc_log_create(struct intel_guc *guc)
                GUC_LOG_ISR_PAGES + 1 +
                GUC_LOG_CRASH_PAGES + 1) << PAGE_SHIFT;
 
-       vma = guc->log_vma;
+       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_memcpy_from_wc(NULL, NULL, 0))) {
+                       /* logging will not be enabled */
+                       i915.guc_log_level = -1;
+                       return;
+               }
+
                vma = guc_allocate_vma(guc, size);
                if (IS_ERR(vma)) {
                        /* logging will be off */
@@ -874,7 +1319,14 @@ static void guc_log_create(struct intel_guc *guc)
                        return;
                }
 
-               guc->log_vma = vma;
+               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 */
@@ -884,7 +1336,37 @@ static void guc_log_create(struct intel_guc *guc)
                (GUC_LOG_CRASH_PAGES << GUC_LOG_CRASH_SHIFT);
 
        offset = i915_ggtt_offset(vma) >> PAGE_SHIFT; /* in pages */
-       guc->log_flags = (offset << GUC_LOG_BUF_ADDR_SHIFT) | flags;
+       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_policies_init(struct guc_policies *policies)
@@ -917,6 +1399,7 @@ static void guc_addon_create(struct intel_guc *guc)
        struct guc_policies *policies;
        struct guc_mmio_reg_state *reg_state;
        struct intel_engine_cs *engine;
+       enum intel_engine_id id;
        struct page *page;
        u32 size;
 
@@ -944,10 +1427,10 @@ static void guc_addon_create(struct intel_guc *guc)
         * so its address won't change after we've told the GuC where
         * to find it.
         */
-       engine = &dev_priv->engine[RCS];
+       engine = dev_priv->engine[RCS];
        ads->golden_context_lrca = engine->status_page.ggtt_offset;
 
-       for_each_engine(engine, dev_priv)
+       for_each_engine(engine, dev_priv, id)
                ads->eng_state_size[engine->guc_id] = intel_lr_context_size(engine);
 
        /* GuC scheduling policies */
@@ -960,7 +1443,7 @@ static void guc_addon_create(struct intel_guc *guc)
        /* MMIO reg state */
        reg_state = (void *)policies + sizeof(struct guc_policies);
 
-       for_each_engine(engine, dev_priv) {
+       for_each_engine(engine, dev_priv, id) {
                reg_state->mmio_white_list[engine->guc_id].mmio_start =
                        engine->mmio_base + GUC_MMIO_WHITE_LIST_START;
 
@@ -1005,6 +1488,7 @@ int i915_guc_submission_init(struct drm_i915_private *dev_priv)
 
        guc->ctx_pool_vma = vma;
        ida_init(&guc->ctx_ids);
+       mutex_init(&guc->action_lock);
        guc_log_create(guc);
        guc_addon_create(guc);
 
@@ -1014,9 +1498,10 @@ int i915_guc_submission_init(struct drm_i915_private *dev_priv)
 int i915_guc_submission_enable(struct drm_i915_private *dev_priv)
 {
        struct intel_guc *guc = &dev_priv->guc;
+       struct drm_i915_gem_request *request;
        struct i915_guc_client *client;
        struct intel_engine_cs *engine;
-       struct drm_i915_gem_request *request;
+       enum intel_engine_id id;
 
        /* client for execbuf submission */
        client = guc_client_alloc(dev_priv,
@@ -1033,7 +1518,7 @@ int i915_guc_submission_enable(struct drm_i915_private *dev_priv)
        guc_init_doorbell_hw(guc);
 
        /* Take over from manual control of ELSP (execlists) */
-       for_each_engine(engine, dev_priv) {
+       for_each_engine(engine, dev_priv, id) {
                engine->submit_request = i915_guc_submit;
 
                /* Replay the current set of previously submitted requests */
@@ -1066,7 +1551,7 @@ void i915_guc_submission_fini(struct drm_i915_private *dev_priv)
        struct intel_guc *guc = &dev_priv->guc;
 
        i915_vma_unpin_and_release(&guc->ads_vma);
-       i915_vma_unpin_and_release(&guc->log_vma);
+       i915_vma_unpin_and_release(&guc->log.vma);
 
        if (guc->ctx_pool_vma)
                ida_destroy(&guc->ctx_ids);
@@ -1087,6 +1572,8 @@ int intel_guc_suspend(struct drm_device *dev)
        if (guc->guc_fw.guc_fw_load_status != GUC_FIRMWARE_SUCCESS)
                return 0;
 
+       gen9_disable_guc_interrupts(dev_priv);
+
        ctx = dev_priv->kernel_context;
 
        data[0] = HOST2GUC_ACTION_ENTER_S_STATE;
@@ -1113,6 +1600,9 @@ int intel_guc_resume(struct drm_device *dev)
        if (guc->guc_fw.guc_fw_load_status != GUC_FIRMWARE_SUCCESS)
                return 0;
 
+       if (i915.guc_log_level >= 0)
+               gen9_enable_guc_interrupts(dev_priv);
+
        ctx = dev_priv->kernel_context;
 
        data[0] = HOST2GUC_ACTION_EXIT_S_STATE;
@@ -1122,3 +1612,104 @@ int intel_guc_resume(struct drm_device *dev)
 
        return host2guc_action(guc, data, ARRAY_SIZE(data));
 }
+
+void i915_guc_capture_logs(struct drm_i915_private *dev_priv)
+{
+       guc_read_update_log_buffer(&dev_priv->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);
+       host2guc_logbuffer_flush_complete(&dev_priv->guc);
+       intel_runtime_pm_put(dev_priv);
+}
+
+void i915_guc_flush_logs(struct drm_i915_private *dev_priv)
+{
+       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(&dev_priv->guc.log.flush_work);
+
+       /* Ask GuC to update the log buffer state */
+       host2guc_force_logbuffer_flush(&dev_priv->guc);
+
+       /* GuC would have updated log buffer by now, so capture it */
+       i915_guc_capture_logs(dev_priv);
+}
+
+void i915_guc_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);
+}
+
+void i915_guc_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);
+}
+
+int i915_guc_log_control(struct drm_i915_private *dev_priv, u64 control_val)
+{
+       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 = host2guc_logging_control(&dev_priv->guc, log_param.value);
+       if (ret < 0) {
+               DRM_DEBUG_DRIVER("host2guc 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(&dev_priv->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.
+                */
+               i915_guc_flush_logs(dev_priv);
+
+               /* 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;
+}