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, 190 insertions, 0 deletions

diff --git a/sound/soc/sof/loader.c b/sound/soc/sof/loader.c
new file mode 100644
index 000000000..0baf316b0
--- /dev/null
+++ b/sound/soc/sof/loader.c
@@ -0,0 +1,190 @@
+// 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>
+//
+// Generic firmware loader.
+//
+
+#include <linux/firmware.h>
+#include "sof-priv.h"
+#include "ops.h"
+
+int snd_sof_load_firmware_raw(struct snd_sof_dev *sdev)
+{
+	struct snd_sof_pdata *plat_data = sdev->pdata;
+	const char *fw_filename;
+	ssize_t ext_man_size;
+	int ret;
+
+	/* Don't request firmware again if firmware is already requested */
+	if (sdev->basefw.fw)
+		return 0;
+
+	fw_filename = kasprintf(GFP_KERNEL, "%s/%s",
+				plat_data->fw_filename_prefix,
+				plat_data->fw_filename);
+	if (!fw_filename)
+		return -ENOMEM;
+
+	ret = request_firmware(&sdev->basefw.fw, fw_filename, sdev->dev);
+
+	if (ret < 0) {
+		dev_err(sdev->dev,
+			"error: sof firmware file is missing, you might need to\n");
+		dev_err(sdev->dev,
+			"       download it from https://github.com/thesofproject/sof-bin/\n");
+		goto err;
+	} else {
+		dev_dbg(sdev->dev, "request_firmware %s successful\n",
+			fw_filename);
+	}
+
+	/* check for extended manifest */
+	ext_man_size = sdev->ipc->ops->fw_loader->parse_ext_manifest(sdev);
+	if (ext_man_size > 0) {
+		/* when no error occurred, drop extended manifest */
+		sdev->basefw.payload_offset = ext_man_size;
+	} else if (!ext_man_size) {
+		/* No extended manifest, so nothing to skip during FW load */
+		dev_dbg(sdev->dev, "firmware doesn't contain extended manifest\n");
+	} else {
+		ret = ext_man_size;
+		dev_err(sdev->dev, "error: firmware %s contains unsupported or invalid extended manifest: %d\n",
+			fw_filename, ret);
+	}
+
+err:
+	kfree(fw_filename);
+
+	return ret;
+}
+EXPORT_SYMBOL(snd_sof_load_firmware_raw);
+
+int snd_sof_load_firmware_memcpy(struct snd_sof_dev *sdev)
+{
+	int ret;
+
+	ret = snd_sof_load_firmware_raw(sdev);
+	if (ret < 0)
+		return ret;
+
+	/* make sure the FW header and file is valid */
+	ret = sdev->ipc->ops->fw_loader->validate(sdev);
+	if (ret < 0) {
+		dev_err(sdev->dev, "error: invalid FW header\n");
+		goto error;
+	}
+
+	/* prepare the DSP for FW loading */
+	ret = snd_sof_dsp_reset(sdev);
+	if (ret < 0) {
+		dev_err(sdev->dev, "error: failed to reset DSP\n");
+		goto error;
+	}
+
+	/* parse and load firmware modules to DSP */
+	if (sdev->ipc->ops->fw_loader->load_fw_to_dsp) {
+		ret = sdev->ipc->ops->fw_loader->load_fw_to_dsp(sdev);
+		if (ret < 0) {
+			dev_err(sdev->dev, "Firmware loading failed\n");
+			goto error;
+		}
+	}
+
+	return 0;
+
+error:
+	release_firmware(sdev->basefw.fw);
+	sdev->basefw.fw = NULL;
+	return ret;
+
+}
+EXPORT_SYMBOL(snd_sof_load_firmware_memcpy);
+
+int snd_sof_run_firmware(struct snd_sof_dev *sdev)
+{
+	int ret;
+
+	init_waitqueue_head(&sdev->boot_wait);
+
+	/* (re-)enable dsp dump */
+	sdev->dbg_dump_printed = false;
+	sdev->ipc_dump_printed = false;
+
+	/* create read-only fw_version debugfs to store boot version info */
+	if (sdev->first_boot) {
+		ret = snd_sof_debugfs_buf_item(sdev, &sdev->fw_version,
+					       sizeof(sdev->fw_version),
+					       "fw_version", 0444);
+		/* errors are only due to memory allocation, not debugfs */
+		if (ret < 0) {
+			dev_err(sdev->dev, "snd_sof_debugfs_buf_item failed\n");
+			return ret;
+		}
+	}
+
+	/* perform pre fw run operations */
+	ret = snd_sof_dsp_pre_fw_run(sdev);
+	if (ret < 0) {
+		dev_err(sdev->dev, "failed pre fw run op\n");
+		return ret;
+	}
+
+	dev_dbg(sdev->dev, "booting DSP firmware\n");
+
+	/* boot the firmware on the DSP */
+	ret = snd_sof_dsp_run(sdev);
+	if (ret < 0) {
+		snd_sof_dsp_dbg_dump(sdev, "Failed to start DSP",
+				     SOF_DBG_DUMP_MBOX | SOF_DBG_DUMP_PCI);
+		return ret;
+	}
+
+	/*
+	 * now wait for the DSP to boot. There are 3 possible outcomes:
+	 * 1. Boot wait times out indicating FW boot failure.
+	 * 2. FW boots successfully and fw_ready op succeeds.
+	 * 3. FW boots but fw_ready op fails.
+	 */
+	ret = wait_event_timeout(sdev->boot_wait,
+				 sdev->fw_state > SOF_FW_BOOT_IN_PROGRESS,
+				 msecs_to_jiffies(sdev->boot_timeout));
+	if (ret == 0) {
+		snd_sof_dsp_dbg_dump(sdev, "Firmware boot failure due to timeout",
+				     SOF_DBG_DUMP_REGS | SOF_DBG_DUMP_MBOX |
+				     SOF_DBG_DUMP_TEXT | SOF_DBG_DUMP_PCI);
+		return -EIO;
+	}
+
+	if (sdev->fw_state == SOF_FW_BOOT_READY_FAILED)
+		return -EIO; /* FW boots but fw_ready op failed */
+
+	dev_dbg(sdev->dev, "firmware boot complete\n");
+	sof_set_fw_state(sdev, SOF_FW_BOOT_COMPLETE);
+
+	/* perform post fw run operations */
+	ret = snd_sof_dsp_post_fw_run(sdev);
+	if (ret < 0) {
+		dev_err(sdev->dev, "error: failed post fw run op\n");
+		return ret;
+	}
+
+	if (sdev->ipc->ops->post_fw_boot)
+		return sdev->ipc->ops->post_fw_boot(sdev);
+
+	return 0;
+}
+EXPORT_SYMBOL(snd_sof_run_firmware);
+
+void snd_sof_fw_unload(struct snd_sof_dev *sdev)
+{
+	/* TODO: support module unloading at runtime */
+	release_firmware(sdev->basefw.fw);
+	sdev->basefw.fw = NULL;
+}
+EXPORT_SYMBOL(snd_sof_fw_unload);