sched_ext: Maintain an online cid mask in the scheduler arenagrafted

Schedulers on the default cid mapping treat [0, nr_online_cids) as the
online set and restart on hotplug. Schedulers that install their own mapping
with scx_bpf_cid_override() have no way to learn which cids are online: the
count no longer identifies members and the CPU-form cpumask is unusable from
cid programs. This is an obvious hole in the cid API.

Add scx_bpf_online_cmask(), a kernel-maintained cmask in the scheduler's
arena, allocated alongside the per-CPU scratch masks and populated after the
cid mapping is finalized and before ops.init(), for child schedulers too.
The pointer stays valid through ops.exit() with no reference to take. It is
the arena offset as a void pointer, the same form struct_ops arena arguments
arrive in. The verifier types the void return as a scalar for the program's
arena cast.

The mask follows the SCX hotplug notifications: seeded from cpu_active_mask
and updated before ops.cid_online/offline() runs, so it lags cpu_online_mask
only inside a hotplug transition. Updates walk the scheduler list under the
lock that also serializes unlinking. Reads are live, not atomic snapshots.
Root initialization excludes hotplug.

v2: Reworded the getter kerneldoc (Andrea Righi).

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

1 files changed, 404 insertions, 0 deletions

diff --git a/sound/soc/sof/compress.c b/sound/soc/sof/compress.c
new file mode 100644
index 000000000..93f237658
--- /dev/null
+++ b/sound/soc/sof/compress.c
@@ -0,0 +1,404 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
+//
+// Copyright 2021 NXP
+//
+// Author: Daniel Baluta <daniel.baluta@nxp.com>
+
+#include <sound/soc.h>
+#include <sound/sof.h>
+#include <sound/compress_driver.h>
+#include "sof-audio.h"
+#include "sof-priv.h"
+#include "sof-utils.h"
+#include "ops.h"
+
+static void sof_set_transferred_bytes(struct sof_compr_stream *sstream,
+				      u64 host_pos, u64 buffer_size)
+{
+	u64 prev_pos;
+	unsigned int copied;
+
+	div64_u64_rem(sstream->copied_total, buffer_size, &prev_pos);
+
+	if (host_pos < prev_pos)
+		copied = (buffer_size - prev_pos) + host_pos;
+	else
+		copied = host_pos - prev_pos;
+
+	sstream->copied_total += copied;
+}
+
+static void snd_sof_compr_fragment_elapsed_work(struct work_struct *work)
+{
+	struct snd_sof_pcm_stream *sps =
+		container_of(work, struct snd_sof_pcm_stream,
+			     period_elapsed_work);
+
+	snd_compr_fragment_elapsed(sps->cstream);
+}
+
+void snd_sof_compr_init_elapsed_work(struct work_struct *work)
+{
+	INIT_WORK(work, snd_sof_compr_fragment_elapsed_work);
+}
+
+/*
+ * sof compr fragment elapse, this could be called in irq thread context
+ */
+void snd_sof_compr_fragment_elapsed(struct snd_compr_stream *cstream)
+{
+	struct snd_soc_pcm_runtime *rtd;
+	struct snd_compr_runtime *crtd;
+	struct snd_soc_component *component;
+	struct sof_compr_stream *sstream;
+	struct snd_sof_pcm *spcm;
+
+	if (!cstream)
+		return;
+
+	rtd = cstream->private_data;
+	crtd = cstream->runtime;
+	sstream = crtd->private_data;
+	component = snd_soc_rtdcom_lookup(rtd, SOF_AUDIO_PCM_DRV_NAME);
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm) {
+		dev_err(component->dev,
+			"fragment elapsed called for unknown stream!\n");
+		return;
+	}
+
+	sof_set_transferred_bytes(sstream, spcm->stream[cstream->direction].posn.host_posn,
+				  crtd->buffer_size);
+
+	/* use the same workqueue-based solution as for PCM, cf. snd_sof_pcm_elapsed */
+	schedule_work(&spcm->stream[cstream->direction].period_elapsed_work);
+}
+
+static int create_page_table(struct snd_soc_component *component,
+			     struct snd_compr_stream *cstream,
+			     unsigned char *dma_area, size_t size)
+{
+	struct snd_dma_buffer *dmab = cstream->runtime->dma_buffer_p;
+	struct snd_soc_pcm_runtime *rtd = cstream->private_data;
+	int dir = cstream->direction;
+	struct snd_sof_pcm *spcm;
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	return snd_sof_create_page_table(component->dev, dmab,
+					 spcm->stream[dir].page_table.area, size);
+}
+
+static int sof_compr_open(struct snd_soc_component *component,
+			  struct snd_compr_stream *cstream)
+{
+	struct snd_soc_pcm_runtime *rtd = cstream->private_data;
+	struct snd_compr_runtime *crtd = cstream->runtime;
+	struct sof_compr_stream *sstream;
+	struct snd_sof_pcm *spcm;
+	int dir;
+
+	sstream = kzalloc_obj(*sstream);
+	if (!sstream)
+		return -ENOMEM;
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm) {
+		kfree(sstream);
+		return -EINVAL;
+	}
+
+	dir = cstream->direction;
+
+	if (spcm->stream[dir].cstream) {
+		kfree(sstream);
+		return -EBUSY;
+	}
+
+	spcm->stream[dir].cstream = cstream;
+	spcm->stream[dir].posn.host_posn = 0;
+	spcm->stream[dir].posn.dai_posn = 0;
+	spcm->prepared[dir] = false;
+
+	crtd->private_data = sstream;
+
+	return 0;
+}
+
+static int sof_compr_free(struct snd_soc_component *component,
+			  struct snd_compr_stream *cstream)
+{
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct sof_compr_stream *sstream = cstream->runtime->private_data;
+	struct snd_soc_pcm_runtime *rtd = cstream->private_data;
+	struct sof_ipc_stream stream;
+	struct snd_sof_pcm *spcm;
+	int ret = 0;
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	stream.hdr.size = sizeof(stream);
+	stream.hdr.cmd = SOF_IPC_GLB_STREAM_MSG | SOF_IPC_STREAM_PCM_FREE;
+	stream.comp_id = spcm->stream[cstream->direction].comp_id;
+
+	if (spcm->prepared[cstream->direction]) {
+		ret = sof_ipc_tx_message_no_reply(sdev->ipc, &stream, sizeof(stream));
+		if (!ret)
+			spcm->prepared[cstream->direction] = false;
+	}
+
+	cancel_work_sync(&spcm->stream[cstream->direction].period_elapsed_work);
+	spcm->stream[cstream->direction].cstream = NULL;
+	kfree(sstream);
+
+	return ret;
+}
+
+static int sof_compr_set_params(struct snd_soc_component *component,
+				struct snd_compr_stream *cstream, struct snd_compr_params *params)
+{
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_soc_pcm_runtime *rtd = cstream->private_data;
+	struct snd_compr_runtime *crtd = cstream->runtime;
+	struct sof_ipc_pcm_params_reply ipc_params_reply;
+	struct sof_ipc_fw_ready *ready = &sdev->fw_ready;
+	struct sof_ipc_fw_version *v = &ready->version;
+	struct sof_compr_stream *sstream;
+	struct sof_ipc_pcm_params *pcm;
+	struct snd_sof_pcm *spcm;
+	size_t ext_data_size;
+	int ret;
+
+	if (v->abi_version < SOF_ABI_VER(3, 22, 0)) {
+		dev_err(component->dev,
+			"Compress params not supported with FW ABI version %d:%d:%d\n",
+			SOF_ABI_VERSION_MAJOR(v->abi_version),
+			SOF_ABI_VERSION_MINOR(v->abi_version),
+			SOF_ABI_VERSION_PATCH(v->abi_version));
+		return -EINVAL;
+	}
+
+	sstream = crtd->private_data;
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+
+	if (!spcm)
+		return -EINVAL;
+
+	ext_data_size = sizeof(params->codec);
+
+	if (sizeof(*pcm) + ext_data_size > sdev->ipc->max_payload_size)
+		return -EINVAL;
+
+	/*
+	 * 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;
+
+	pcm = kzalloc(sizeof(*pcm) + ext_data_size, GFP_KERNEL);
+	if (!pcm)
+		return -ENOMEM;
+
+	cstream->dma_buffer.dev.type = SNDRV_DMA_TYPE_DEV_SG;
+	cstream->dma_buffer.dev.dev = sdev->dev;
+	ret = snd_compr_malloc_pages(cstream, crtd->buffer_size);
+	if (ret < 0)
+		goto out;
+
+	ret = create_page_table(component, cstream, crtd->dma_area, crtd->dma_bytes);
+	if (ret < 0)
+		goto out;
+
+	pcm->params.buffer.pages = PFN_UP(crtd->dma_bytes);
+	pcm->hdr.size = sizeof(*pcm) + ext_data_size;
+	pcm->hdr.cmd = SOF_IPC_GLB_STREAM_MSG | SOF_IPC_STREAM_PCM_PARAMS;
+
+	pcm->comp_id = spcm->stream[cstream->direction].comp_id;
+	pcm->params.hdr.size = sizeof(pcm->params) + ext_data_size;
+	pcm->params.buffer.phy_addr = spcm->stream[cstream->direction].page_table.addr;
+	pcm->params.buffer.size = crtd->dma_bytes;
+	pcm->params.direction = cstream->direction;
+	pcm->params.channels = params->codec.ch_out;
+	pcm->params.rate = params->codec.sample_rate;
+	pcm->params.buffer_fmt = SOF_IPC_BUFFER_INTERLEAVED;
+	pcm->params.frame_fmt = SOF_IPC_FRAME_S32_LE;
+	pcm->params.sample_container_bytes =
+		snd_pcm_format_physical_width(SNDRV_PCM_FORMAT_S32) >> 3;
+	pcm->params.host_period_bytes = params->buffer.fragment_size;
+	pcm->params.ext_data_length = ext_data_size;
+
+	memcpy((u8 *)pcm->params.ext_data, &params->codec, ext_data_size);
+
+	ret = sof_ipc_tx_message(sdev->ipc, pcm, sizeof(*pcm) + ext_data_size,
+				 &ipc_params_reply, sizeof(ipc_params_reply));
+	if (ret < 0) {
+		dev_err(component->dev, "error ipc failed\n");
+		goto out;
+	}
+
+	ret = snd_sof_set_stream_data_offset(sdev, &spcm->stream[cstream->direction],
+					     ipc_params_reply.posn_offset);
+	if (ret < 0) {
+		dev_err(component->dev, "Invalid stream data offset for Compr %u\n",
+			le32_to_cpu(spcm->pcm.pcm_id));
+		goto out;
+	}
+
+	sstream->sampling_rate = params->codec.sample_rate;
+	sstream->channels = params->codec.ch_out;
+	sstream->sample_container_bytes = pcm->params.sample_container_bytes;
+	sstream->codec_params = params->codec;
+
+	spcm->prepared[cstream->direction] = true;
+
+out:
+	kfree(pcm);
+
+	return ret;
+}
+
+static int sof_compr_get_params(struct snd_soc_component *component,
+				struct snd_compr_stream *cstream, struct snd_codec *params)
+{
+	struct sof_compr_stream *sstream = cstream->runtime->private_data;
+
+	*params = sstream->codec_params;
+
+	return 0;
+}
+
+static int sof_compr_trigger(struct snd_soc_component *component,
+			     struct snd_compr_stream *cstream, int cmd)
+{
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_soc_pcm_runtime *rtd = cstream->private_data;
+	struct sof_ipc_stream stream;
+	struct snd_sof_pcm *spcm;
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	stream.hdr.size = sizeof(stream);
+	stream.hdr.cmd = SOF_IPC_GLB_STREAM_MSG;
+	stream.comp_id = spcm->stream[cstream->direction].comp_id;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		stream.hdr.cmd |= SOF_IPC_STREAM_TRIG_START;
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+		stream.hdr.cmd |= SOF_IPC_STREAM_TRIG_STOP;
+		break;
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		stream.hdr.cmd |= SOF_IPC_STREAM_TRIG_PAUSE;
+		break;
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		stream.hdr.cmd |= SOF_IPC_STREAM_TRIG_RELEASE;
+		break;
+	default:
+		dev_err(component->dev, "error: unhandled trigger cmd %d\n", cmd);
+		break;
+	}
+
+	return sof_ipc_tx_message_no_reply(sdev->ipc, &stream, sizeof(stream));
+}
+
+static int sof_compr_copy_playback(struct snd_compr_runtime *rtd,
+				   char __user *buf, size_t count)
+{
+	void *ptr;
+	unsigned int offset, n;
+	int ret;
+
+	div_u64_rem(rtd->total_bytes_available, rtd->buffer_size, &offset);
+	ptr = rtd->dma_area + offset;
+	n = rtd->buffer_size - offset;
+
+	if (count < n) {
+		ret = copy_from_user(ptr, buf, count);
+	} else {
+		ret = copy_from_user(ptr, buf, n);
+		ret += copy_from_user(rtd->dma_area, buf + n, count - n);
+	}
+
+	return count - ret;
+}
+
+static int sof_compr_copy_capture(struct snd_compr_runtime *rtd,
+				  char __user *buf, size_t count)
+{
+	void *ptr;
+	unsigned int offset, n;
+	int ret;
+
+	div_u64_rem(rtd->total_bytes_transferred, rtd->buffer_size, &offset);
+	ptr = rtd->dma_area + offset;
+	n = rtd->buffer_size - offset;
+
+	if (count < n) {
+		ret = copy_to_user(buf, ptr, count);
+	} else {
+		ret = copy_to_user(buf, ptr, n);
+		ret += copy_to_user(buf + n, rtd->dma_area, count - n);
+	}
+
+	return count - ret;
+}
+
+static int sof_compr_copy(struct snd_soc_component *component,
+			  struct snd_compr_stream *cstream,
+			  char __user *buf, size_t count)
+{
+	struct snd_compr_runtime *rtd = cstream->runtime;
+
+	if (count > rtd->buffer_size)
+		count = rtd->buffer_size;
+
+	if (cstream->direction == SND_COMPRESS_PLAYBACK)
+		return sof_compr_copy_playback(rtd, buf, count);
+	else
+		return sof_compr_copy_capture(rtd, buf, count);
+}
+
+static int sof_compr_pointer(struct snd_soc_component *component,
+			     struct snd_compr_stream *cstream,
+			     struct snd_compr_tstamp64 *tstamp)
+{
+	struct snd_sof_pcm *spcm;
+	struct snd_soc_pcm_runtime *rtd = cstream->private_data;
+	struct sof_compr_stream *sstream = cstream->runtime->private_data;
+
+	spcm = snd_sof_find_spcm_dai(component, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	if (!sstream->channels || !sstream->sample_container_bytes)
+		return -EBUSY;
+
+	tstamp->sampling_rate = sstream->sampling_rate;
+	tstamp->copied_total = sstream->copied_total;
+	tstamp->pcm_io_frames = div_u64(spcm->stream[cstream->direction].posn.dai_posn,
+					sstream->channels * sstream->sample_container_bytes);
+
+	return 0;
+}
+
+struct snd_compress_ops sof_compressed_ops = {
+	.open		= sof_compr_open,
+	.free		= sof_compr_free,
+	.set_params	= sof_compr_set_params,
+	.get_params	= sof_compr_get_params,
+	.trigger	= sof_compr_trigger,
+	.pointer	= sof_compr_pointer,
+	.copy		= sof_compr_copy,
+};
+EXPORT_SYMBOL(sof_compressed_ops);