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, 229 insertions, 0 deletions

diff --git a/sound/soc/sof/control.c b/sound/soc/sof/control.c
new file mode 100644
index 000000000..74d997a4f
--- /dev/null
+++ b/sound/soc/sof/control.c
@@ -0,0 +1,229 @@
+// 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>
+//
+
+/* Mixer Controls */
+
+#include <linux/pm_runtime.h>
+#include <linux/leds.h>
+#include "sof-priv.h"
+#include "sof-audio.h"
+
+int snd_sof_volume_get(struct snd_kcontrol *kcontrol,
+		       struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_mixer_control *sm = (struct soc_mixer_control *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = sm->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->volume_get)
+		return tplg_ops->control->volume_get(scontrol, ucontrol);
+
+	return 0;
+}
+
+int snd_sof_volume_put(struct snd_kcontrol *kcontrol,
+		       struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_mixer_control *sm = (struct soc_mixer_control *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = sm->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->volume_put)
+		return tplg_ops->control->volume_put(scontrol, ucontrol);
+
+	return false;
+}
+
+int snd_sof_volume_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
+{
+	struct soc_mixer_control *sm = (struct soc_mixer_control *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = sm->dobj.private;
+	unsigned int channels = scontrol->num_channels;
+	int platform_max;
+
+	if (!sm->platform_max)
+		sm->platform_max = sm->max;
+	platform_max = sm->platform_max;
+
+	if (platform_max == 1 && !strstr(kcontrol->id.name, " Volume"))
+		uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
+	else
+		uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+
+	uinfo->count = channels;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = platform_max - sm->min;
+	return 0;
+}
+
+int snd_sof_switch_get(struct snd_kcontrol *kcontrol,
+		       struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_mixer_control *sm = (struct soc_mixer_control *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = sm->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->switch_get)
+		return tplg_ops->control->switch_get(scontrol, ucontrol);
+
+	return 0;
+}
+
+int snd_sof_switch_put(struct snd_kcontrol *kcontrol,
+		       struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_mixer_control *sm = (struct soc_mixer_control *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = sm->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->switch_put)
+		return tplg_ops->control->switch_put(scontrol, ucontrol);
+
+	return false;
+}
+
+int snd_sof_enum_get(struct snd_kcontrol *kcontrol,
+		     struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_enum *se = (struct soc_enum *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = se->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->enum_get)
+		return tplg_ops->control->enum_get(scontrol, ucontrol);
+
+	return 0;
+}
+
+int snd_sof_enum_put(struct snd_kcontrol *kcontrol,
+		     struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_enum *se = (struct soc_enum *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = se->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->enum_put)
+		return tplg_ops->control->enum_put(scontrol, ucontrol);
+
+	return false;
+}
+
+int snd_sof_bytes_get(struct snd_kcontrol *kcontrol,
+		      struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_bytes_ext *be = (struct soc_bytes_ext *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = be->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->bytes_get)
+		return tplg_ops->control->bytes_get(scontrol, ucontrol);
+
+	return 0;
+}
+
+int snd_sof_bytes_put(struct snd_kcontrol *kcontrol,
+		      struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_bytes_ext *be = (struct soc_bytes_ext *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = be->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->bytes_put)
+		return tplg_ops->control->bytes_put(scontrol, ucontrol);
+
+	return 0;
+}
+
+int snd_sof_bytes_ext_put(struct snd_kcontrol *kcontrol,
+			  const unsigned int __user *binary_data,
+			  unsigned int size)
+{
+	struct soc_bytes_ext *be = (struct soc_bytes_ext *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = be->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	/* make sure we have at least a header */
+	if (size < sizeof(struct snd_ctl_tlv))
+		return -EINVAL;
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->bytes_ext_put)
+		return tplg_ops->control->bytes_ext_put(scontrol, binary_data, size);
+
+	return 0;
+}
+
+int snd_sof_bytes_ext_volatile_get(struct snd_kcontrol *kcontrol, unsigned int __user *binary_data,
+				   unsigned int size)
+{
+	struct soc_bytes_ext *be = (struct soc_bytes_ext *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = be->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+	int ret, err;
+
+	/* ignore the ext_volatile_get call if the callbacks are not provided */
+	if (!tplg_ops || !tplg_ops->control ||
+	    !tplg_ops->control->bytes_ext_volatile_get)
+		return 0;
+
+	ret = pm_runtime_resume_and_get(scomp->dev);
+	if (ret < 0 && ret != -EACCES) {
+		dev_err_ratelimited(scomp->dev, "%s: failed to resume %d\n", __func__, ret);
+		return ret;
+	}
+
+	/* Make sure the DSP/firmware is booted up */
+	ret = snd_sof_boot_dsp_firmware(sdev);
+	if (!ret)
+		ret = tplg_ops->control->bytes_ext_volatile_get(scontrol,
+								binary_data,
+								size);
+
+	err = pm_runtime_put_autosuspend(scomp->dev);
+	if (err < 0)
+		dev_err_ratelimited(scomp->dev, "%s: failed to idle %d\n", __func__, err);
+
+	return ret;
+}
+
+int snd_sof_bytes_ext_get(struct snd_kcontrol *kcontrol,
+			  unsigned int __user *binary_data,
+			  unsigned int size)
+{
+	struct soc_bytes_ext *be = (struct soc_bytes_ext *)kcontrol->private_value;
+	struct snd_sof_control *scontrol = be->dobj.private;
+	struct snd_soc_component *scomp = scontrol->scomp;
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
+	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
+	if (tplg_ops && tplg_ops->control && tplg_ops->control->bytes_ext_get)
+		return tplg_ops->control->bytes_ext_get(scontrol, binary_data, size);
+
+	return 0;
+}