drm/i915/guc: Add onion teardown to the GuC setup

Starting with intel_guc_loader, down to intel_guc_submission
and finally to intel_guc_log.

v2:
  - Null execbuf client outside guc_client_free (Daniele)
  - Assert if things try to get allocated twice (Daniele/Joonas)
  - Null guc->log.buf_addr when destroyed (Daniele)
  - Newline between returning success and error labels (Joonas)
  - Remove some unnecessary comments (Joonas)
  - Keep guc_log_create_extras naming convention (Joonas)
  - Helper function guc_log_has_extras (Joonas)
  - No need for separate relay_channel create/destroy. It's just another extra.
  - No need to nullify guc->log.flush_wq when destroyed (Joonas)
  - Hoist the check for has_extras out of guc_log_create_extras (Joonas)
  - Try to do i915_guc_log_register/unregister calls (kind of) symmetric (Daniele)
  - Make sure initel_guc_fini is not called before init is ever called (Daniele)

v3:
  - Remove unnecessary parenthesis (Joonas)
  - Check for logs enabled on debugfs registration
  - Rebase on top of Tvrtko's "Fix request re-submission after reset"

v4:
  - Rebased
  - Comment around enabling/disabling interrupts inside GuC logging (Joonas)
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drivers/gpu/drm/i915/i915_drv.c

@@ -549,6 +549,8 @@ static const struct vga_switcheroo_client_ops i915_switcheroo_ops = {
 static void i915_gem_fini(struct drm_i915_private *dev_priv)
 {
 	mutex_lock(&dev_priv->drm.struct_mutex);
+	if (i915.enable_guc_loading)
+		intel_uc_fini_hw(dev_priv);
 	i915_gem_cleanup_engines(dev_priv);
 	i915_gem_context_fini(dev_priv);
 	mutex_unlock(&dev_priv->drm.struct_mutex);
@@ -609,7 +611,7 @@ static int i915_load_modeset_init(struct drm_device *dev)
 
 	ret = i915_gem_init(dev_priv);
 	if (ret)
-		goto cleanup_irq;
+		goto cleanup_uc;
 
 	intel_modeset_gem_init(dev);
 
@@ -631,9 +633,9 @@ static int i915_load_modeset_init(struct drm_device *dev)
 	if (i915_gem_suspend(dev_priv))
 		DRM_ERROR("failed to idle hardware; continuing to unload!\n");
 	i915_gem_fini(dev_priv);
+cleanup_uc:
+	intel_uc_fini_fw(dev_priv);
 cleanup_irq:
-	intel_guc_fini(dev_priv);
-	intel_huc_fini(dev_priv);
 	drm_irq_uninstall(dev);
 	intel_teardown_gmbus(dev_priv);
 cleanup_csr:
@@ -1369,9 +1371,8 @@ void i915_driver_unload(struct drm_device *dev)
 	/* Flush any outstanding unpin_work. */
 	drain_workqueue(dev_priv->wq);
 
-	intel_guc_fini(dev_priv);
-	intel_huc_fini(dev_priv);
 	i915_gem_fini(dev_priv);
+	intel_uc_fini_fw(dev_priv);
 	intel_fbc_cleanup_cfb(dev_priv);
 
 	intel_power_domains_fini(dev_priv);

drivers/gpu/drm/i915/i915_gem.c

@@ -4608,10 +4608,12 @@ int i915_gem_init_hw(struct drm_i915_private *dev_priv)
 
 	intel_mocs_init_l3cc_table(dev_priv);
 
-	/* We can't enable contexts until all firmware is loaded */
-	ret = intel_uc_init_hw(dev_priv);
-	if (ret)
-		goto out;
+	if (i915.enable_guc_loading) {
+		/* We can't enable contexts until all firmware is loaded */
+		ret = intel_uc_init_hw(dev_priv);
+		if (ret)
+			goto out;
+	}
 
 out:
 	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);

drivers/gpu/drm/i915/i915_guc_submission.c

@@ -911,7 +911,6 @@ guc_client_alloc(struct drm_i915_private *dev_priv,
 	ida_simple_remove(&guc->ctx_ids, client->ctx_index);
 err_client:
 	kfree(client);
-
 	return ERR_PTR(ret);
 }
 
@@ -937,7 +936,7 @@ static void guc_policies_init(struct guc_policies *policies)
 	policies->is_valid = 1;
 }
 
-static void guc_addon_create(struct intel_guc *guc)
+static int guc_addon_create(struct intel_guc *guc)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
 	struct i915_vma *vma;
@@ -953,14 +952,13 @@ static void guc_addon_create(struct intel_guc *guc)
 	enum intel_engine_id id;
 	u32 base;
 
-	vma = guc->ads_vma;
-	if (!vma) {
-		vma = intel_guc_allocate_vma(guc, PAGE_ALIGN(sizeof(*blob)));
-		if (IS_ERR(vma))
-			return;
+	GEM_BUG_ON(guc->ads_vma);
 
-		guc->ads_vma = vma;
-	}
+	vma = intel_guc_allocate_vma(guc, PAGE_ALIGN(sizeof(*blob)));
+	if (IS_ERR(vma))
+		return PTR_ERR(vma);
+
+	guc->ads_vma = vma;
 
 	page = i915_vma_first_page(vma);
 	blob = kmap(page);
@@ -997,6 +995,13 @@ static void guc_addon_create(struct intel_guc *guc)
 	blob->ads.reg_state_addr = base + ptr_offset(blob, reg_state);
 
 	kunmap(page);
+
+	return 0;
+}
+
+static void guc_addon_destroy(struct intel_guc *guc)
+{
+	i915_vma_unpin_and_release(&guc->ads_vma);
 }
 
 /*
@@ -1011,6 +1016,7 @@ int i915_guc_submission_init(struct drm_i915_private *dev_priv)
 	struct intel_guc *guc = &dev_priv->guc;
 	struct i915_vma *vma;
 	void *vaddr;
+	int ret;
 
 	if (!HAS_GUC_SCHED(dev_priv))
 		return 0;
@@ -1020,10 +1026,10 @@ int i915_guc_submission_init(struct drm_i915_private *dev_priv)
 	i915_guc_submission_disable(dev_priv);
 
 	if (!i915.enable_guc_submission)
-		return 0; /* not enabled  */
+		return 0;
 
 	if (guc->ctx_pool)
-		return 0; /* already allocated */
+		return 0;
 
 	vma = intel_guc_allocate_vma(guc, gemsize);
 	if (IS_ERR(vma))
@@ -1031,15 +1037,23 @@ int i915_guc_submission_init(struct drm_i915_private *dev_priv)
 
 	guc->ctx_pool = vma;
 
-	vaddr = i915_gem_object_pin_map(vma->obj, I915_MAP_WB);
-	if (IS_ERR(vaddr))
-		goto err;
+	vaddr = i915_gem_object_pin_map(guc->ctx_pool->obj, I915_MAP_WB);
+	if (IS_ERR(vaddr)) {
+		ret = PTR_ERR(vaddr);
+		goto err_vma;
+	}
 
 	guc->ctx_pool_vaddr = vaddr;
 
+	ret = intel_guc_log_create(guc);
+	if (ret < 0)
+		goto err_vaddr;
+
+	ret = guc_addon_create(guc);
+	if (ret < 0)
+		goto err_log;
+
 	ida_init(&guc->ctx_ids);
-	intel_guc_log_create(guc);
-	guc_addon_create(guc);
 
 	guc->execbuf_client = guc_client_alloc(dev_priv,
 					       INTEL_INFO(dev_priv)->ring_mask,
@@ -1047,14 +1061,37 @@ int i915_guc_submission_init(struct drm_i915_private *dev_priv)
 					       dev_priv->kernel_context);
 	if (IS_ERR(guc->execbuf_client)) {
 		DRM_ERROR("Failed to create GuC client for execbuf!\n");
-		goto err;
+		ret = PTR_ERR(guc->execbuf_client);
+		goto err_ads;
 	}
 
 	return 0;
 
-err:
-	i915_guc_submission_fini(dev_priv);
-	return -ENOMEM;
+err_ads:
+	guc_addon_destroy(guc);
+err_log:
+	intel_guc_log_destroy(guc);
+err_vaddr:
+	i915_gem_object_unpin_map(guc->ctx_pool->obj);
+err_vma:
+	i915_vma_unpin_and_release(&guc->ctx_pool);
+	return ret;
+}
+
+void i915_guc_submission_fini(struct drm_i915_private *dev_priv)
+{
+	struct intel_guc *guc = &dev_priv->guc;
+
+	if (!i915.enable_guc_submission)
+		return 0;
+
+	guc_client_free(guc->execbuf_client);
+	guc->execbuf_client = NULL;
+	ida_destroy(&guc->ctx_ids);
+	guc_addon_destroy(guc);
+	intel_guc_log_destroy(guc);
+	i915_gem_object_unpin_map(guc->ctx_pool->obj);
+	i915_vma_unpin_and_release(&guc->ctx_pool);
 }
 
 static void guc_reset_wq(struct i915_guc_client *client)
@@ -1199,26 +1236,6 @@ void i915_guc_submission_disable(struct drm_i915_private *dev_priv)
 	intel_engines_reset_default_submission(dev_priv);
 }
 
-void i915_guc_submission_fini(struct drm_i915_private *dev_priv)
-{
-	struct intel_guc *guc = &dev_priv->guc;
-	struct i915_guc_client *client;
-
-	client = fetch_and_zero(&guc->execbuf_client);
-	if (client && !IS_ERR(client))
-		guc_client_free(client);
-
-	i915_vma_unpin_and_release(&guc->ads_vma);
-	i915_vma_unpin_and_release(&guc->log.vma);
-
-	if (guc->ctx_pool_vaddr) {
-		ida_destroy(&guc->ctx_ids);
-		i915_gem_object_unpin_map(guc->ctx_pool->obj);
-	}
-
-	i915_vma_unpin_and_release(&guc->ctx_pool);
-}
-
 /**
  * intel_guc_suspend() - notify GuC entering suspend state
  * @dev_priv:	i915 device private

drivers/gpu/drm/i915/intel_guc_loader.c

@@ -430,24 +430,3 @@ int intel_guc_select_fw(struct intel_guc *guc)
 
 	return 0;
 }
-
-/**
- * intel_guc_fini() - clean up all allocated resources
- * @dev_priv:	i915 device private
- */
-void intel_guc_fini(struct drm_i915_private *dev_priv)
-{
-	struct intel_uc_fw *guc_fw = &dev_priv->guc.fw;
-	struct drm_i915_gem_object *obj;
-
-	mutex_lock(&dev_priv->drm.struct_mutex);
-	i915_guc_submission_disable(dev_priv);
-	i915_guc_submission_fini(dev_priv);
-	mutex_unlock(&dev_priv->drm.struct_mutex);
-
-	obj = fetch_and_zero(&guc_fw->obj);
-	if (obj)
-		i915_gem_object_put(obj);
-
-	guc_fw->fetch_status = INTEL_UC_FIRMWARE_NONE;
-}

drivers/gpu/drm/i915/intel_guc_log.c

@@ -66,7 +66,6 @@ static int guc_log_control(struct intel_guc *guc, u32 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.
@@ -139,45 +138,15 @@ static struct rchan_callbacks relay_callbacks = {
 	.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)
+static int guc_log_relay_file_create(struct intel_guc *guc)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
 	struct dentry *log_dir;
 	int ret;
 
+	if (i915.guc_log_level < 0)
+		return 0;
+
 	/* For now create the log file in /sys/kernel/debug/dri/0 dir */
 	log_dir = dev_priv->drm.primary->debugfs_root;
 
@@ -198,7 +167,7 @@ static int guc_log_create_relay_file(struct intel_guc *guc)
 	}
 
 	ret = relay_late_setup_files(guc->log.relay_chan, "guc_log", log_dir);
-	if (ret) {
+	if (ret < 0 && ret != -EEXIST) {
 		DRM_ERROR("Couldn't associate relay chan with file %d\n", ret);
 		return ret;
 	}
@@ -371,31 +340,6 @@ static void guc_read_update_log_buffer(struct intel_guc *guc)
 	}
 }
 
-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 =
@@ -404,120 +348,105 @@ static void capture_logs_work(struct work_struct *work)
 	guc_log_capture_logs(guc);
 }
 
+static bool guc_log_has_extras(struct intel_guc *guc)
+{
+	return 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;
+	struct rchan *guc_log_relay_chan;
+	size_t n_subbufs, subbuf_size;
+	int ret = 0;
 
 	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;
-	}
+	GEM_BUG_ON(guc_log_has_extras(guc));
 
-	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;
+	/* 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)) {
+		DRM_ERROR("Couldn't map log buffer pages %d\n", ret);
+		return PTR_ERR(vaddr);
 	}
 
-	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;
-		}
-	}
+	guc->log.buf_addr = vaddr;
 
-	return 0;
-}
+	 /* Keep the size of sub buffers same as shared log buffer */
+	subbuf_size = guc->log.vma->obj->base.size;
 
-void intel_guc_log_create(struct intel_guc *guc)
-{
-	struct i915_vma *vma;
-	unsigned long offset;
-	uint32_t size, flags;
+	/* 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;
 
-	if (i915.guc_log_level > GUC_LOG_VERBOSITY_MAX)
-		i915.guc_log_level = GUC_LOG_VERBOSITY_MAX;
+	/* 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.
+	 */
+	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");
 
-	/* 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;
+		ret = -ENOMEM;
+		goto err_vaddr;
+	}
 
-	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;
-		}
+	GEM_BUG_ON(guc_log_relay_chan->subbuf_size < subbuf_size);
+	guc->log.relay_chan = guc_log_relay_chan;
 
-		vma = intel_guc_allocate_vma(guc, size);
-		if (IS_ERR(vma)) {
-			/* logging will be off */
-			i915.guc_log_level = -1;
-			return;
-		}
+	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) {
+		DRM_ERROR("Couldn't allocate the wq for GuC logging\n");
+		ret = -ENOMEM;
+		goto err_relaychan;
+	}
 
-		guc->log.vma = vma;
+	return 0;
 
-		if (guc_log_create_extras(guc)) {
-			guc_log_cleanup(guc);
-			i915_vma_unpin_and_release(&guc->log.vma);
-			i915.guc_log_level = -1;
-			return;
-		}
-	}
+err_relaychan:
+	relay_close(guc->log.relay_chan);
+err_vaddr:
+	i915_gem_object_unpin_map(guc->log.vma->obj);
+	guc->log.buf_addr = NULL;
+	return ret;
+}
 
-	/* 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);
+static void guc_log_destroy_extras(struct intel_guc *guc)
+{
+	/*
+	 * It's possible that extras were never allocated because guc_log_level
+	 * was < 0 at the time
+	 **/
+	if (!guc_log_has_extras(guc))
+		return;
 
-	offset = guc_ggtt_offset(vma) >> PAGE_SHIFT; /* in pages */
-	guc->log.flags = (offset << GUC_LOG_BUF_ADDR_SHIFT) | flags;
+	destroy_workqueue(guc->log.flush_wq);
+	relay_close(guc->log.relay_chan);
+	i915_gem_object_unpin_map(guc->log.vma->obj);
+	guc->log.buf_addr = NULL;
 }
 
 static int guc_log_late_setup(struct intel_guc *guc)
@@ -527,24 +456,25 @@ static int guc_log_late_setup(struct intel_guc *guc)
 
 	lockdep_assert_held(&dev_priv->drm.struct_mutex);
 
-	if (i915.guc_log_level < 0)
-		return -EINVAL;
+	if (!guc_log_has_extras(guc)) {
+		/* 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;
+	}
 
-	/* 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);
+	ret = guc_log_relay_file_create(guc);
 	if (ret)
-		goto err;
-
-	ret = guc_log_create_relay_file(guc);
-	if (ret)
-		goto err;
+		goto err_extras;
 
 	return 0;
+
+err_extras:
+	guc_log_destroy_extras(guc);
 err:
-	guc_log_cleanup(guc);
 	/* logging will remain off */
 	i915.guc_log_level = -1;
 	return ret;
@@ -586,6 +516,72 @@ static void guc_flush_logs(struct intel_guc *guc)
 	guc_log_capture_logs(guc);
 }
 
+int intel_guc_log_create(struct intel_guc *guc)
+{
+	struct i915_vma *vma;
+	unsigned long offset;
+	uint32_t size, flags;
+	int ret;
+
+	GEM_BUG_ON(guc->log.vma);
+
+	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;
+
+	/* 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())) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	vma = intel_guc_allocate_vma(guc, size);
+	if (IS_ERR(vma)) {
+		ret = PTR_ERR(vma);
+		goto err;
+	}
+
+	guc->log.vma = vma;
+
+	if (i915.guc_log_level >= 0) {
+		ret = guc_log_create_extras(guc);
+		if (ret < 0)
+			goto err_vma;
+	}
+
+	/* 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;
+
+	return 0;
+
+err_vma:
+	i915_vma_unpin_and_release(&guc->log.vma);
+err:
+	/* logging will be off */
+	i915.guc_log_level = -1;
+	return ret;
+}
+
+void intel_guc_log_destroy(struct intel_guc *guc)
+{
+	guc_log_destroy_extras(guc);
+	i915_vma_unpin_and_release(&guc->log.vma);
+}
+
 int i915_guc_log_control(struct drm_i915_private *dev_priv, u64 control_val)
 {
 	struct intel_guc *guc = &dev_priv->guc;
@@ -609,17 +605,22 @@ int i915_guc_log_control(struct drm_i915_private *dev_priv, u64 control_val)
 		return ret;
 	}
 
-	i915.guc_log_level = log_param.verbosity;
+	if (log_param.logging_enabled) {
+		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) {
+		/* 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. Try again now, just in case.
+		 */
 		ret = guc_log_late_setup(guc);
-		if (!ret)
-			gen9_enable_guc_interrupts(dev_priv);
-	} else if (!log_param.logging_enabled) {
+		if (ret < 0) {
+			DRM_DEBUG_DRIVER("GuC log late setup failed %d\n", ret);
+			return ret;
+		}
+
+		/* GuC logging is currently the only user of Guc2Host interrupts */
+		gen9_enable_guc_interrupts(dev_priv);
+	} else {
 		/* 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
@@ -629,9 +630,6 @@ int i915_guc_log_control(struct drm_i915_private *dev_priv, u64 control_val)
 
 		/* 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;
@@ -639,7 +637,7 @@ int i915_guc_log_control(struct drm_i915_private *dev_priv, u64 control_val)
 
 void i915_guc_log_register(struct drm_i915_private *dev_priv)
 {
-	if (!i915.enable_guc_submission)
+	if (!i915.enable_guc_submission || i915.guc_log_level < 0)
 		return;
 
 	mutex_lock(&dev_priv->drm.struct_mutex);
@@ -653,6 +651,8 @@ void i915_guc_log_unregister(struct drm_i915_private *dev_priv)
 		return;
 
 	mutex_lock(&dev_priv->drm.struct_mutex);
-	guc_log_cleanup(&dev_priv->guc);
+	/* GuC logging is currently the only user of Guc2Host interrupts */
+	gen9_disable_guc_interrupts(dev_priv);
+	guc_log_destroy_extras(&dev_priv->guc);
 	mutex_unlock(&dev_priv->drm.struct_mutex);
 }

drivers/gpu/drm/i915/intel_uc.c

@@ -95,24 +95,41 @@ void intel_uc_init_fw(struct drm_i915_private *dev_priv)
 		intel_uc_prepare_fw(dev_priv, &dev_priv->guc.fw);
 }
 
+void intel_uc_fini_fw(struct drm_i915_private *dev_priv)
+{
+	struct intel_uc_fw *guc_fw = &dev_priv->guc.fw;
+	struct intel_uc_fw *huc_fw = &dev_priv->huc.fw;
+	struct drm_i915_gem_object *obj;
+
+	obj = fetch_and_zero(&guc_fw->obj);
+	if (obj)
+		i915_gem_object_put(obj);
+
+	guc_fw->fetch_status = INTEL_UC_FIRMWARE_NONE;
+
+	obj = fetch_and_zero(&huc_fw->obj);
+	if (obj)
+		i915_gem_object_put(obj);
+
+	huc_fw->fetch_status = INTEL_UC_FIRMWARE_NONE;
+}
+
 int intel_uc_init_hw(struct drm_i915_private *dev_priv)
 {
 	int ret, attempts;
 
-	/* GuC not enabled, nothing to do */
-	if (!i915.enable_guc_loading)
-		return 0;
-
 	gen9_reset_guc_interrupts(dev_priv);
 
 	/* We need to notify the guc whenever we change the GGTT */
 	i915_ggtt_enable_guc(dev_priv);
 
-	if (i915.enable_guc_submission) {
-		ret = i915_guc_submission_init(dev_priv);
-		if (ret)
-			goto err;
-	}
+	/*
+	 * This is stuff we need to have available at fw load time
+	 * if we are planning to enable submission later
+	 */
+	ret = i915_guc_submission_init(dev_priv);
+	if (ret)
+		goto err_guc;
 
 	/* WaEnableuKernelHeaderValidFix:skl */
 	/* WaEnableGuCBootHashCheckNotSet:skl,bxt,kbl */
@@ -150,7 +167,7 @@ int intel_uc_init_hw(struct drm_i915_private *dev_priv)
 
 		ret = i915_guc_submission_enable(dev_priv);
 		if (ret)
-			goto err_submission;
+			goto err_interrupts;
 	}
 
 	return 0;
@@ -164,11 +181,11 @@ int intel_uc_init_hw(struct drm_i915_private *dev_priv)
 	 * nonfatal error (i.e. it doesn't prevent driver load, but
 	 * marks the GPU as wedged until reset).
 	 */
+err_interrupts:
+	gen9_disable_guc_interrupts(dev_priv);
 err_submission:
-	if (i915.enable_guc_submission)
-		i915_guc_submission_fini(dev_priv);
-
-err:
+	i915_guc_submission_fini(dev_priv);
+err_guc:
 	i915_ggtt_disable_guc(dev_priv);
 
 	DRM_ERROR("GuC init failed\n");
@@ -185,6 +202,16 @@ int intel_uc_init_hw(struct drm_i915_private *dev_priv)
 	return ret;
 }
 
+void intel_uc_fini_hw(struct drm_i915_private *dev_priv)
+{
+	if (i915.enable_guc_submission) {
+		i915_guc_submission_disable(dev_priv);
+		gen9_disable_guc_interrupts(dev_priv);
+	}
+	i915_guc_submission_fini(dev_priv);
+	i915_ggtt_disable_guc(dev_priv);
+}
+
 /*
  * Read GuC command/status register (SOFT_SCRATCH_0)
  * Return true if it contains a response rather than a command

drivers/gpu/drm/i915/intel_uc.h

@@ -187,7 +187,9 @@ struct intel_huc {
 void intel_uc_sanitize_options(struct drm_i915_private *dev_priv);
 void intel_uc_init_early(struct drm_i915_private *dev_priv);
 void intel_uc_init_fw(struct drm_i915_private *dev_priv);
+void intel_uc_fini_fw(struct drm_i915_private *dev_priv);
 int intel_uc_init_hw(struct drm_i915_private *dev_priv);
+void intel_uc_fini_hw(struct drm_i915_private *dev_priv);
 void intel_uc_prepare_fw(struct drm_i915_private *dev_priv,
 			 struct intel_uc_fw *uc_fw);
 int intel_guc_send(struct intel_guc *guc, const u32 *action, u32 len);
@@ -196,7 +198,6 @@ int intel_guc_sample_forcewake(struct intel_guc *guc);
 /* intel_guc_loader.c */
 int intel_guc_select_fw(struct intel_guc *guc);
 int intel_guc_init_hw(struct intel_guc *guc);
-void intel_guc_fini(struct drm_i915_private *dev_priv);
 const char *intel_uc_fw_status_repr(enum intel_uc_fw_status status);
 int intel_guc_suspend(struct drm_i915_private *dev_priv);
 int intel_guc_resume(struct drm_i915_private *dev_priv);
@@ -212,10 +213,11 @@ void i915_guc_submission_fini(struct drm_i915_private *dev_priv);
 struct i915_vma *intel_guc_allocate_vma(struct intel_guc *guc, u32 size);
 
 /* intel_guc_log.c */
-void intel_guc_log_create(struct intel_guc *guc);
+int intel_guc_log_create(struct intel_guc *guc);
+void intel_guc_log_destroy(struct intel_guc *guc);
+int i915_guc_log_control(struct drm_i915_private *dev_priv, u64 control_val);
 void i915_guc_log_register(struct drm_i915_private *dev_priv);
 void i915_guc_log_unregister(struct drm_i915_private *dev_priv);
-int i915_guc_log_control(struct drm_i915_private *dev_priv, u64 control_val);
 
 static inline u32 guc_ggtt_offset(struct i915_vma *vma)
 {