Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 870 insertions, 0 deletions

diff --git a/sound/soc/sof/pcm.c b/sound/soc/sof/pcm.c
new file mode 100644
index 000000000..f748d0721
--- /dev/null
+++ b/sound/soc/sof/pcm.c
@@ -0,0 +1,870 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
+//
+// This file is provided under a dual BSD/GPLv2 license.  When using or
+// redistributing this file, you may do so under either license.
+//
+// Copyright(c) 2018 Intel Corporation
+//
+// Author: Liam Girdwood <liam.r.girdwood@linux.intel.com>
+//
+// PCM Layer, interface between ALSA and IPC.
+//
+
+#include <linux/pm_runtime.h>
+#include <sound/pcm_params.h>
+#include <sound/sof.h>
+#include <trace/events/sof.h>
+#include "sof-of-dev.h"
+#include "sof-priv.h"
+#include "sof-audio.h"
+#include "sof-utils.h"
+#include "ops.h"
+
+/*
+ * sof pcm period elapse work
+ */
+static void snd_sof_pcm_period_elapsed_work(struct work_struct *work)
+{
+	struct snd_sof_pcm_stream *sps =
+		container_of(work, struct snd_sof_pcm_stream,
+			     period_elapsed_work);
+
+	snd_pcm_period_elapsed(sps->substream);
+}
+
+void snd_sof_pcm_init_elapsed_work(struct work_struct *work)
+{
+	 INIT_WORK(work, snd_sof_pcm_period_elapsed_work);
+}
+
+/*
+ * sof pcm period elapse, this could be called at irq thread context.
+ */
+void snd_sof_pcm_period_elapsed(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
+	struct snd_soc_component *component =
+		snd_soc_rtdcom_lookup(rtd, SOF_AUDIO_PCM_DRV_NAME);
+	struct snd_sof_pcm *spcm;
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm) {
+		dev_err(component->dev,
+			"error: period elapsed for unknown stream!\n");
+		return;
+	}
+
+	/*
+	 * snd_pcm_period_elapsed() can be called in interrupt context
+	 * before IRQ_HANDLED is returned. Inside snd_pcm_period_elapsed(),
+	 * when the PCM is done draining or xrun happened, a STOP IPC will
+	 * then be sent and this IPC will hit IPC timeout.
+	 * To avoid sending IPC before the previous IPC is handled, we
+	 * schedule delayed work here to call the snd_pcm_period_elapsed().
+	 */
+	queue_work(system_highpri_wq, &spcm->stream[substream->stream].period_elapsed_work);
+}
+EXPORT_SYMBOL(snd_sof_pcm_period_elapsed);
+
+static int
+sof_pcm_setup_connected_widgets(struct snd_sof_dev *sdev, struct snd_soc_pcm_runtime *rtd,
+				struct snd_sof_pcm *spcm, struct snd_pcm_hw_params *params,
+				struct snd_sof_platform_stream_params *platform_params, int dir)
+{
+	struct snd_soc_dai *dai;
+	int ret, j;
+
+	/* query DAPM for list of connected widgets and set them up */
+	for_each_rtd_cpu_dais(rtd, j, dai) {
+		struct snd_soc_dapm_widget_list *list;
+
+		ret = snd_soc_dapm_dai_get_connected_widgets(dai, dir, &list,
+							     dpcm_end_walk_at_be);
+		if (ret < 0) {
+			spcm_err(spcm, dir, "dai %s has no valid %s path\n",
+				 dai->name, snd_pcm_direction_name(dir));
+			return ret;
+		}
+
+		spcm->stream[dir].list = list;
+
+		ret = sof_widget_list_prepare(sdev, spcm, params, platform_params, dir);
+		if (ret < 0) {
+			spcm_err(spcm, dir, "widget list prepare failed\n");
+			spcm->stream[dir].list = NULL;
+			snd_soc_dapm_dai_free_widgets(&list);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static struct snd_sof_widget *snd_sof_find_swidget_by_comp_id(struct snd_sof_dev *sdev,
+							      int comp_id)
+{
+	struct snd_sof_widget *swidget;
+
+	list_for_each_entry(swidget, &sdev->widget_list, list) {
+		if (comp_id == swidget->comp_id)
+			return swidget;
+	}
+
+	return NULL;
+}
+
+static int sof_pcm_hw_params(struct snd_soc_component *component,
+			     struct snd_pcm_substream *substream,
+			     struct snd_pcm_hw_params *params)
+{
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+	const struct sof_ipc_pcm_ops *pcm_ops = sof_ipc_get_ops(sdev, pcm);
+	struct snd_sof_platform_stream_params *platform_params;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_sof_widget *host_widget;
+	struct snd_sof_pcm *spcm;
+	int ret;
+
+	/* nothing to do for BE */
+	if (rtd->dai_link->no_pcm)
+		return 0;
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	spcm_dbg(spcm, substream->stream, "Entry: hw_params\n");
+
+	if (!sdev->dspless_mode_selected) {
+		/*
+		 * Make sure that the DSP is booted up, which might not be the
+		 * case if the on-demand DSP boot is used
+		 */
+		ret = snd_sof_boot_dsp_firmware(sdev);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * Handle repeated calls to hw_params() without free_pcm() in
+	 * between. At least ALSA OSS emulation depends on this.
+	 */
+	if (spcm->prepared[substream->stream] && pcm_ops && pcm_ops->hw_free) {
+		ret = pcm_ops->hw_free(component, substream);
+		if (ret < 0)
+			return ret;
+
+		spcm->prepared[substream->stream] = false;
+	}
+
+	platform_params = &spcm->platform_params[substream->stream];
+	ret = snd_sof_pcm_platform_hw_params(sdev, substream, params, platform_params);
+	if (ret < 0) {
+		spcm_err(spcm, substream->stream, "platform hw params failed\n");
+		return ret;
+	}
+
+	/* if this is a repeated hw_params without hw_free, skip setting up widgets */
+	if (!spcm->stream[substream->stream].list) {
+		ret = sof_pcm_setup_connected_widgets(sdev, rtd, spcm, params, platform_params,
+						      substream->stream);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (!sdev->dspless_mode_selected) {
+		int host_comp_id = spcm->stream[substream->stream].comp_id;
+
+		host_widget = snd_sof_find_swidget_by_comp_id(sdev, host_comp_id);
+		if (!host_widget) {
+			spcm_err(spcm, substream->stream,
+				 "failed to find host widget with comp_id %d\n", host_comp_id);
+			return -EINVAL;
+		}
+
+		/* set the host DMA ID */
+		if (tplg_ops && tplg_ops->host_config)
+			tplg_ops->host_config(sdev, host_widget, platform_params);
+	}
+
+	/* create compressed page table for audio firmware */
+	if (runtime->buffer_changed) {
+		struct snd_dma_buffer *dmab = snd_pcm_get_dma_buf(substream);
+
+		ret = snd_sof_create_page_table(component->dev, dmab,
+				spcm->stream[substream->stream].page_table.area,
+				runtime->dma_bytes);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* save pcm hw_params */
+	memcpy(&spcm->params[substream->stream], params, sizeof(*params));
+
+	return 0;
+}
+
+static int sof_pcm_stream_free(struct snd_sof_dev *sdev,
+			       struct snd_pcm_substream *substream,
+			       struct snd_sof_pcm *spcm, int dir,
+			       bool free_widget_list)
+{
+	const struct sof_ipc_pcm_ops *pcm_ops = sof_ipc_get_ops(sdev, pcm);
+	int ret;
+	int err = 0;
+
+	if (spcm->prepared[substream->stream]) {
+		/* stop DMA first if needed */
+		if (pcm_ops && pcm_ops->platform_stop_during_hw_free)
+			snd_sof_pcm_platform_trigger(sdev, substream,
+						     SNDRV_PCM_TRIGGER_STOP);
+
+		/* free PCM in the DSP */
+		if (pcm_ops && pcm_ops->hw_free) {
+			ret = pcm_ops->hw_free(sdev->component, substream);
+			if (ret < 0) {
+				spcm_err(spcm, substream->stream,
+					 "pcm_ops->hw_free failed %d\n", ret);
+				err = ret;
+			}
+		}
+
+		spcm->prepared[substream->stream] = false;
+		spcm->pending_stop[substream->stream] = false;
+	}
+
+	/* reset the DMA */
+	ret = snd_sof_pcm_platform_hw_free(sdev, substream);
+	if (ret < 0) {
+		spcm_err(spcm, substream->stream,
+			 "platform hw free failed %d\n", ret);
+		if (!err)
+			err = ret;
+	}
+
+	/* free widget list */
+	if (free_widget_list) {
+		ret = sof_widget_list_free(sdev, spcm, dir);
+		if (ret < 0) {
+			spcm_err(spcm, substream->stream,
+				 "sof_widget_list_free failed %d\n", ret);
+			if (!err)
+				err = ret;
+		}
+	}
+
+	return err;
+}
+
+int sof_pcm_free_all_streams(struct snd_sof_dev *sdev)
+{
+	struct snd_pcm_substream *substream;
+	struct snd_sof_pcm *spcm;
+	int dir, ret;
+
+	list_for_each_entry(spcm, &sdev->pcm_list, list) {
+		for_each_pcm_streams(dir) {
+			substream = spcm->stream[dir].substream;
+
+			if (!substream || !substream->runtime ||
+			    spcm->stream[dir].suspend_ignored)
+				continue;
+
+			if (spcm->stream[dir].list) {
+				ret = sof_pcm_stream_free(sdev, substream, spcm,
+							  dir, true);
+				if (ret < 0)
+					return ret;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int sof_pcm_hw_free(struct snd_soc_component *component,
+			   struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_pcm *spcm;
+	int ret;
+
+	/* nothing to do for BE */
+	if (rtd->dai_link->no_pcm)
+		return 0;
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	spcm_dbg(spcm, substream->stream, "Entry: hw_free\n");
+
+	ret = sof_pcm_stream_free(sdev, substream, spcm, substream->stream, true);
+
+	/* unprepare and free the list of DAPM widgets */
+	sof_widget_list_unprepare(sdev, spcm, substream->stream);
+
+	cancel_work_sync(&spcm->stream[substream->stream].period_elapsed_work);
+
+	return ret;
+}
+
+static int sof_pcm_prepare(struct snd_soc_component *component,
+			   struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	const struct sof_ipc_pcm_ops *pcm_ops = sof_ipc_get_ops(sdev, pcm);
+	struct snd_sof_platform_stream_params *platform_params;
+	struct snd_soc_dapm_widget_list *list;
+	struct snd_pcm_hw_params *params;
+	struct snd_sof_pcm *spcm;
+	int dir = substream->stream;
+	int ret;
+
+	/* nothing to do for BE */
+	if (rtd->dai_link->no_pcm)
+		return 0;
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	spcm_dbg(spcm, substream->stream, "Entry: prepare\n");
+
+	if (spcm->prepared[substream->stream]) {
+		if (!spcm->pending_stop[substream->stream])
+			return 0;
+
+		/*
+		 * this case should be reached in case of xruns where we absolutely
+		 * want to free-up and reset all PCM/DMA resources
+		 */
+		ret = sof_pcm_stream_free(sdev, substream, spcm, substream->stream, true);
+		if (ret < 0)
+			return ret;
+	}
+
+	ret = sof_pcm_hw_params(component, substream, &spcm->params[substream->stream]);
+	if (ret < 0) {
+		spcm_err(spcm, substream->stream,
+			 "failed to set hw_params after resume\n");
+		return ret;
+	}
+
+	list = spcm->stream[dir].list;
+	params = &spcm->params[substream->stream];
+	platform_params = &spcm->platform_params[substream->stream];
+	ret = sof_widget_list_setup(sdev, spcm, params, platform_params, dir);
+	if (ret < 0) {
+		dev_err(sdev->dev, "failed widget list set up for pcm %d dir %u\n",
+			le32_to_cpu(spcm->pcm.pcm_id), dir);
+		spcm->stream[dir].list = NULL;
+		snd_soc_dapm_dai_free_widgets(&list);
+		return ret;
+	}
+
+	if (pcm_ops && pcm_ops->hw_params) {
+		ret = pcm_ops->hw_params(component, substream, params, platform_params);
+		if (ret < 0)
+			return ret;
+	}
+
+	spcm->prepared[substream->stream] = true;
+
+	return 0;
+}
+
+/*
+ * FE dai link trigger actions are always executed in non-atomic context because
+ * they involve IPC's.
+ */
+static int sof_pcm_trigger(struct snd_soc_component *component,
+			   struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	const struct sof_ipc_pcm_ops *pcm_ops = sof_ipc_get_ops(sdev, pcm);
+	struct snd_sof_pcm *spcm;
+	bool reset_hw_params = false;
+	bool ipc_first = false;
+	int ret = 0;
+
+	/* nothing to do for BE */
+	if (rtd->dai_link->no_pcm)
+		return 0;
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	spcm_dbg(spcm, substream->stream, "Entry: trigger (cmd: %d)\n", cmd);
+
+	spcm->pending_stop[substream->stream] = false;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		ipc_first = true;
+		break;
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		if (pcm_ops && pcm_ops->ipc_first_on_start)
+			ipc_first = true;
+		break;
+	case SNDRV_PCM_TRIGGER_START:
+		if (spcm->stream[substream->stream].suspend_ignored) {
+			/*
+			 * This case will be triggered when INFO_RESUME is
+			 * not supported, no need to re-start streams that
+			 * remained enabled in D0ix.
+			 */
+			spcm->stream[substream->stream].suspend_ignored = false;
+			return 0;
+		}
+
+		if (pcm_ops && pcm_ops->ipc_first_on_start)
+			ipc_first = true;
+		break;
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+		/*
+		 * If DSP D0I3 is allowed during S0iX, set the suspend_ignored flag for
+		 * D0I3-compatible streams to keep the firmware pipeline running
+		 */
+		if (pcm_ops && pcm_ops->d0i3_supported_in_s0ix &&
+		    sdev->system_suspend_target == SOF_SUSPEND_S0IX &&
+		    spcm->stream[substream->stream].d0i3_compatible) {
+			spcm->stream[substream->stream].suspend_ignored = true;
+			return 0;
+		}
+
+		/* On suspend the DMA must be stopped in DSPless mode */
+		if (sdev->dspless_mode_selected)
+			reset_hw_params = true;
+
+		fallthrough;
+	case SNDRV_PCM_TRIGGER_STOP:
+		ipc_first = true;
+		if (pcm_ops && pcm_ops->reset_hw_params_during_stop)
+			reset_hw_params = true;
+		break;
+	default:
+		spcm_err(spcm, substream->stream, "Unhandled trigger cmd %d\n", cmd);
+		return -EINVAL;
+	}
+
+	if (!ipc_first)
+		snd_sof_pcm_platform_trigger(sdev, substream, cmd);
+
+	if (pcm_ops && pcm_ops->trigger)
+		ret = pcm_ops->trigger(component, substream, cmd);
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+	case SNDRV_PCM_TRIGGER_START:
+		/* invoke platform trigger to start DMA only if pcm_ops is successful */
+		if (ipc_first && !ret)
+			snd_sof_pcm_platform_trigger(sdev, substream, cmd);
+		break;
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+	case SNDRV_PCM_TRIGGER_STOP:
+		/* invoke platform trigger to stop DMA even if pcm_ops isn't set or if it failed */
+		if (!pcm_ops || !pcm_ops->platform_stop_during_hw_free)
+			snd_sof_pcm_platform_trigger(sdev, substream, cmd);
+
+		/*
+		 * set the pending_stop flag to indicate that pipeline stop has been delayed.
+		 * This will be used later to stop the pipelines during prepare when recovering
+		 * from xruns.
+		 */
+		if (pcm_ops && pcm_ops->platform_stop_during_hw_free &&
+		    cmd == SNDRV_PCM_TRIGGER_STOP)
+			spcm->pending_stop[substream->stream] = true;
+		break;
+	default:
+		break;
+	}
+
+	/* free PCM if reset_hw_params is set and the STOP IPC is successful */
+	if (!ret && reset_hw_params)
+		ret = sof_pcm_stream_free(sdev, substream, spcm, substream->stream, false);
+
+	return ret;
+}
+
+static snd_pcm_uframes_t sof_pcm_pointer(struct snd_soc_component *component,
+					 struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	const struct sof_ipc_pcm_ops *pcm_ops = sof_ipc_get_ops(sdev, pcm);
+	struct snd_sof_pcm *spcm;
+	snd_pcm_uframes_t host, dai;
+	int ret = -EOPNOTSUPP;
+
+	/* nothing to do for BE */
+	if (rtd->dai_link->no_pcm)
+		return 0;
+
+	if (pcm_ops && pcm_ops->pointer)
+		ret = pcm_ops->pointer(component, substream, &host);
+
+	if (ret != -EOPNOTSUPP)
+		return ret ? ret : host;
+
+	/* use dsp ops pointer callback directly if set */
+	if (sof_ops(sdev)->pcm_pointer)
+		return sof_ops(sdev)->pcm_pointer(sdev, substream);
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	/* read position from DSP */
+	host = bytes_to_frames(substream->runtime,
+			       spcm->stream[substream->stream].posn.host_posn);
+	dai = bytes_to_frames(substream->runtime,
+			      spcm->stream[substream->stream].posn.dai_posn);
+
+	trace_sof_pcm_pointer_position(sdev, spcm, substream, host, dai);
+
+	return host;
+}
+
+static int sof_pcm_open(struct snd_soc_component *component,
+			struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	const struct snd_sof_dsp_ops *ops = sof_ops(sdev);
+	struct snd_sof_pcm *spcm;
+	struct snd_soc_tplg_stream_caps *caps;
+	int ret;
+
+	/* nothing to do for BE */
+	if (rtd->dai_link->no_pcm)
+		return 0;
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	spcm_dbg(spcm, substream->stream, "Entry: open\n");
+
+	caps = &spcm->pcm.caps[substream->stream];
+
+	/* set runtime config */
+	runtime->hw.info = ops->hw_info; /* platform-specific */
+
+	/* set any runtime constraints based on topology */
+	runtime->hw.formats = le64_to_cpu(caps->formats);
+	runtime->hw.period_bytes_min = le32_to_cpu(caps->period_size_min);
+	runtime->hw.period_bytes_max = le32_to_cpu(caps->period_size_max);
+	runtime->hw.periods_min = le32_to_cpu(caps->periods_min);
+	runtime->hw.periods_max = le32_to_cpu(caps->periods_max);
+
+	/*
+	 * caps->buffer_size_min is not used since the
+	 * snd_pcm_hardware structure only defines buffer_bytes_max
+	 */
+	runtime->hw.buffer_bytes_max = le32_to_cpu(caps->buffer_size_max);
+
+	/* set wait time - TODO: come from topology */
+	substream->wait_time = 500;
+
+	spcm->stream[substream->stream].posn.host_posn = 0;
+	spcm->stream[substream->stream].posn.dai_posn = 0;
+	spcm->stream[substream->stream].substream = substream;
+	spcm->prepared[substream->stream] = false;
+
+	ret = snd_sof_pcm_platform_open(sdev, substream);
+	if (ret < 0) {
+		spcm_err(spcm, substream->stream,
+			 "platform pcm open failed %d\n", ret);
+		return ret;
+	}
+
+	spcm_dbg(spcm, substream->stream, "period bytes min %zd, max %zd\n",
+		 runtime->hw.period_bytes_min, runtime->hw.period_bytes_max);
+	spcm_dbg(spcm, substream->stream, "period count min %d, max %d\n",
+		 runtime->hw.periods_min, runtime->hw.periods_max);
+	spcm_dbg(spcm, substream->stream, "buffer bytes max %zd\n", runtime->hw.buffer_bytes_max);
+
+	return 0;
+}
+
+static int sof_pcm_close(struct snd_soc_component *component,
+			 struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_pcm *spcm;
+	int err;
+
+	/* nothing to do for BE */
+	if (rtd->dai_link->no_pcm)
+		return 0;
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	spcm_dbg(spcm, substream->stream, "Entry: close\n");
+
+	err = snd_sof_pcm_platform_close(sdev, substream);
+	if (err < 0) {
+		spcm_err(spcm, substream->stream,
+			 "platform pcm close failed %d\n", err);
+		/*
+		 * keep going, no point in preventing the close
+		 * from happening
+		 */
+	}
+
+	spcm->stream[substream->stream].substream = NULL;
+
+	return 0;
+}
+
+/*
+ * Pre-allocate playback/capture audio buffer pages.
+ * no need to explicitly release memory preallocated by sof_pcm_new in pcm_free
+ * snd_pcm_lib_preallocate_free_for_all() is called by the core.
+ */
+static int sof_pcm_new(struct snd_soc_component *component,
+		       struct snd_soc_pcm_runtime *rtd)
+{
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_pcm *spcm;
+	struct snd_pcm *pcm = rtd->pcm;
+	struct snd_soc_tplg_stream_caps *caps;
+	int stream = SNDRV_PCM_STREAM_PLAYBACK;
+
+	/* find SOF PCM for this RTD */
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm) {
+		dev_warn(component->dev, "warn: can't find PCM with DAI ID %d\n",
+			 rtd->dai_link->id);
+		return 0;
+	}
+
+	dev_dbg(spcm->scomp->dev, "pcm%u (%s): Entry: pcm_new\n",
+		le32_to_cpu(spcm->pcm.pcm_id), spcm->pcm.pcm_name);
+
+	/* do we need to pre-allocate playback audio buffer pages */
+	if (!spcm->pcm.playback)
+		goto capture;
+
+	caps = &spcm->pcm.caps[stream];
+
+	if (!pcm->streams[stream].substream) {
+		spcm_err(spcm, stream, "NULL playback substream!\n");
+		return -EINVAL;
+	}
+
+	/* pre-allocate playback audio buffer pages */
+	spcm_dbg(spcm, stream, "allocate %s playback DMA buffer size 0x%x max 0x%x\n",
+		 caps->name, caps->buffer_size_min, caps->buffer_size_max);
+
+	snd_pcm_set_managed_buffer(pcm->streams[stream].substream,
+				   SNDRV_DMA_TYPE_DEV_SG, sdev->dev,
+				   0, le32_to_cpu(caps->buffer_size_max));
+
+	/* Set the PCM device name for HDMI playback */
+	if (!strncmp(pcm->id, "HDMI", 4)) {
+		int hdmi_idx;
+
+		/*
+		 * Make sure that the name is in"HDMI<SPACE>x" format as this is
+		 * expected by user space.
+		 * See alsa-lib's __snd_pcm_info_eld_fixup_check() which is
+		 * guarding the __snd_pcm_info_eld_fixup() in
+		 * snd_ctl_hw_pcm_info() and snd_pcm_hw_info() library functions
+		 */
+		if (sscanf(pcm->id, "HDMI%d", &hdmi_idx) == 1)
+			snprintf(pcm->name, sizeof(pcm->name), "HDMI %d",
+				 hdmi_idx);
+		else
+			strscpy(pcm->name, pcm->id, sizeof(pcm->name));
+	}
+capture:
+	stream = SNDRV_PCM_STREAM_CAPTURE;
+
+	/* do we need to pre-allocate capture audio buffer pages */
+	if (!spcm->pcm.capture)
+		return 0;
+
+	caps = &spcm->pcm.caps[stream];
+
+	if (!pcm->streams[stream].substream) {
+		spcm_err(spcm, stream, "NULL capture substream!\n");
+		return -EINVAL;
+	}
+
+	/* pre-allocate capture audio buffer pages */
+	spcm_dbg(spcm, stream, "allocate %s capture DMA buffer size 0x%x max 0x%x\n",
+		 caps->name, caps->buffer_size_min, caps->buffer_size_max);
+
+	snd_pcm_set_managed_buffer(pcm->streams[stream].substream,
+				   SNDRV_DMA_TYPE_DEV_SG, sdev->dev,
+				   0, le32_to_cpu(caps->buffer_size_max));
+
+	return 0;
+}
+
+/* fixup the BE DAI link to match any values from topology */
+int sof_pcm_dai_link_fixup(struct snd_soc_pcm_runtime *rtd, struct snd_pcm_hw_params *params)
+{
+	struct snd_interval *rate = hw_param_interval(params,
+			SNDRV_PCM_HW_PARAM_RATE);
+	struct snd_interval *channels = hw_param_interval(params,
+						SNDRV_PCM_HW_PARAM_CHANNELS);
+	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
+	struct snd_soc_component *component =
+		snd_soc_rtdcom_lookup(rtd, SOF_AUDIO_PCM_DRV_NAME);
+	struct snd_sof_dai *dai =
+		snd_sof_find_dai(component, (char *)rtd->dai_link->name);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	const struct sof_ipc_pcm_ops *pcm_ops = sof_ipc_get_ops(sdev, pcm);
+
+	/* no topology exists for this BE, try a common configuration */
+	if (!dai) {
+		dev_warn(component->dev,
+			 "warning: no topology found for BE DAI %s config\n",
+			 rtd->dai_link->name);
+
+		/*  set 48k, stereo, 16bits by default */
+		rate->min = 48000;
+		rate->max = 48000;
+
+		channels->min = 2;
+		channels->max = 2;
+
+		snd_mask_none(fmt);
+		snd_mask_set_format(fmt, SNDRV_PCM_FORMAT_S16_LE);
+
+		return 0;
+	}
+
+	if (pcm_ops && pcm_ops->dai_link_fixup)
+		return pcm_ops->dai_link_fixup(rtd, params);
+
+	return 0;
+}
+EXPORT_SYMBOL(sof_pcm_dai_link_fixup);
+
+static int sof_pcm_probe(struct snd_soc_component *component)
+{
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_pdata *plat_data = sdev->pdata;
+	const char *tplg_filename;
+	int ret;
+
+	/*
+	 * make sure the device is pm_runtime_active before loading the
+	 * topology and initiating IPC or bus transactions
+	 */
+	ret = pm_runtime_resume_and_get(component->dev);
+	if (ret < 0 && ret != -EACCES)
+		return ret;
+
+	/* load the default topology */
+	sdev->component = component;
+
+	tplg_filename = devm_kasprintf(sdev->dev, GFP_KERNEL,
+				       "%s/%s",
+				       plat_data->tplg_filename_prefix,
+				       plat_data->tplg_filename);
+	if (!tplg_filename) {
+		ret = -ENOMEM;
+		goto pm_error;
+	}
+
+	ret = snd_sof_load_topology(component, tplg_filename);
+	if (ret < 0)
+		dev_err(component->dev, "error: failed to load DSP topology %d\n",
+			ret);
+
+pm_error:
+	pm_runtime_put_autosuspend(component->dev);
+
+	return ret;
+}
+
+static void sof_pcm_remove(struct snd_soc_component *component)
+{
+	/* remove topology */
+	snd_soc_tplg_component_remove(component);
+}
+
+static int sof_pcm_ack(struct snd_soc_component *component,
+		       struct snd_pcm_substream *substream)
+{
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+
+	return snd_sof_pcm_platform_ack(sdev, substream);
+}
+
+static snd_pcm_sframes_t sof_pcm_delay(struct snd_soc_component *component,
+				       struct snd_pcm_substream *substream)
+{
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	const struct sof_ipc_pcm_ops *pcm_ops = sof_ipc_get_ops(sdev, pcm);
+
+	if (pcm_ops && pcm_ops->delay)
+		return pcm_ops->delay(component, substream);
+
+	return 0;
+}
+
+void snd_sof_new_platform_drv(struct snd_sof_dev *sdev)
+{
+	struct snd_soc_component_driver *pd = &sdev->plat_drv;
+	struct snd_sof_pdata *plat_data = sdev->pdata;
+	const char *drv_name;
+
+	if (plat_data->machine)
+		drv_name = plat_data->machine->drv_name;
+	else if (plat_data->of_machine)
+		drv_name = plat_data->of_machine->drv_name;
+	else
+		drv_name = NULL;
+
+	pd->name = "sof-audio-component";
+	pd->probe = sof_pcm_probe;
+	pd->remove = sof_pcm_remove;
+	pd->open = sof_pcm_open;
+	pd->close = sof_pcm_close;
+	pd->hw_params = sof_pcm_hw_params;
+	pd->prepare = sof_pcm_prepare;
+	pd->hw_free = sof_pcm_hw_free;
+	pd->trigger = sof_pcm_trigger;
+	pd->pointer = sof_pcm_pointer;
+	pd->ack = sof_pcm_ack;
+	pd->delay = sof_pcm_delay;
+
+#if IS_ENABLED(CONFIG_SND_SOC_SOF_COMPRESS)
+	pd->compress_ops = &sof_compressed_ops;
+#endif
+
+	pd->pcm_new = sof_pcm_new;
+	pd->ignore_machine = drv_name;
+	pd->be_pcm_base = SOF_BE_PCM_BASE;
+	pd->use_dai_pcm_id = true;
+	pd->topology_name_prefix = "sof";
+
+	 /* increment module refcount when a pcm is opened */
+	pd->module_get_upon_open = 1;
+
+	pd->legacy_dai_naming = 1;
+
+	/*
+	 * The fixup is only needed when the DSP is in use as with the DSPless
+	 * mode we are directly using the audio interface
+	 */
+	if (!sdev->dspless_mode_selected)
+		pd->be_hw_params_fixup = sof_pcm_dai_link_fixup;
+}