// SPDX-License-Identifier: GPL-2.0-only
//
// Copyright(c) 2021-2022 Intel Corporation
//
// Authors: Cezary Rojewski <cezary.rojewski@intel.com>
//          Amadeusz Slawinski <amadeuszx.slawinski@linux.intel.com>
//

#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/slab.h>
#include <sound/hdaudio_ext.h>
#include "avs.h"
#include "messages.h"
#include "registers.h"
#include "trace.h"

#define AVS_IPC_TIMEOUT_MS	300
#define AVS_D0IX_DELAY_MS	300

static int
avs_dsp_set_d0ix(struct avs_dev *adev, bool enable)
{
	struct avs_ipc *ipc = adev->ipc;
	int ret;

	/* Is transition required? */
	if (ipc->in_d0ix == enable)
		return 0;

	ret = avs_dsp_op(adev, set_d0ix, enable);
	if (ret) {
		/* Prevent further d0ix attempts on conscious IPC failure. */
		if (ret == -AVS_EIPC)
			atomic_inc(&ipc->d0ix_disable_depth);

		ipc->in_d0ix = false;
		return ret;
	}

	ipc->in_d0ix = enable;
	return 0;
}

static void avs_dsp_schedule_d0ix(struct avs_dev *adev, struct avs_ipc_msg *tx)
{
	if (atomic_read(&adev->ipc->d0ix_disable_depth))
		return;

	mod_delayed_work(system_power_efficient_wq, &adev->ipc->d0ix_work,
			 msecs_to_jiffies(AVS_D0IX_DELAY_MS));
}

static void avs_dsp_d0ix_work(struct work_struct *work)
{
	struct avs_ipc *ipc = container_of(work, struct avs_ipc, d0ix_work.work);

	avs_dsp_set_d0ix(to_avs_dev(ipc->dev), true);
}

static int avs_dsp_wake_d0i0(struct avs_dev *adev, struct avs_ipc_msg *tx)
{
	struct avs_ipc *ipc = adev->ipc;

	if (!atomic_read(&ipc->d0ix_disable_depth)) {
		cancel_delayed_work_sync(&ipc->d0ix_work);
		return avs_dsp_set_d0ix(adev, false);
	}

	return 0;
}

int avs_dsp_disable_d0ix(struct avs_dev *adev)
{
	struct avs_ipc *ipc = adev->ipc;

	/* Prevent PG only on the first disable. */
	if (atomic_inc_return(&ipc->d0ix_disable_depth) == 1) {
		cancel_delayed_work_sync(&ipc->d0ix_work);
		return avs_dsp_set_d0ix(adev, false);
	}

	return 0;
}

int avs_dsp_enable_d0ix(struct avs_dev *adev)
{
	struct avs_ipc *ipc = adev->ipc;

	if (atomic_dec_and_test(&ipc->d0ix_disable_depth))
		queue_delayed_work(system_power_efficient_wq, &ipc->d0ix_work,
				   msecs_to_jiffies(AVS_D0IX_DELAY_MS));
	return 0;
}

static void avs_dsp_recovery(struct avs_dev *adev)
{
	struct avs_soc_component *acomp;
	unsigned int core_mask;
	int ret;

	mutex_lock(&adev->comp_list_mutex);
	/* disconnect all running streams */
	list_for_each_entry(acomp, &adev->comp_list, node) {
		struct snd_soc_pcm_runtime *rtd;
		struct snd_soc_card *card;

		card = acomp->base.card;
		if (!card)
			continue;

		for_each_card_rtds(card, rtd) {
			struct snd_pcm *pcm;
			int dir;

			pcm = rtd->pcm;
			if (!pcm || rtd->dai_link->no_pcm)
				continue;

			for_each_pcm_streams(dir) {
				struct snd_pcm_substream *substream;

				substream = pcm->streams[dir].substream;
				if (!substream || !substream->runtime)
					continue;

				/* No need for _irq() as we are in nonatomic context. */
				snd_pcm_stream_lock(substream);
				snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
				snd_pcm_stream_unlock(substream);
			}
		}
	}
	mutex_unlock(&adev->comp_list_mutex);

	/* forcibly shutdown all cores */
	core_mask = GENMASK(adev->hw_cfg.dsp_cores - 1, 0);
	avs_dsp_core_disable(adev, core_mask);

	/* attempt dsp reboot */
	ret = avs_dsp_boot_firmware(adev, true);
	if (ret < 0)
		dev_err(adev->dev, "dsp reboot failed: %d\n", ret);

	pm_runtime_mark_last_busy(adev->dev);
	pm_runtime_enable(adev->dev);
	pm_request_autosuspend(adev->dev);

	atomic_set(&adev->ipc->recovering, 0);
}

static void avs_dsp_recovery_work(struct work_struct *work)
{
	struct avs_ipc *ipc = container_of(work, struct avs_ipc, recovery_work);

	avs_dsp_recovery(to_avs_dev(ipc->dev));
}

static void avs_dsp_exception_caught(struct avs_dev *adev, union avs_notify_msg *msg)
{
	struct avs_ipc *ipc = adev->ipc;

	/* Account for the double-exception case. */
	ipc->ready = false;

	if (!atomic_add_unless(&ipc->recovering, 1, 1)) {
		dev_err(adev->dev, "dsp recovery is already in progress\n");
		return;
	}

	dev_crit(adev->dev, "communication severed, rebooting dsp..\n");

	/* Avoid deadlock as the exception may be the response to SET_D0IX. */
	if (current_work() != &ipc->d0ix_work.work)
		cancel_delayed_work_sync(&ipc->d0ix_work);
	ipc->in_d0ix = false;
	/* Re-enabled on recovery completion. */
	pm_runtime_disable(adev->dev);

	/* Process received notification. */
	avs_dsp_op(adev, coredump, msg);

	schedule_work(&ipc->recovery_work);
}

static void avs_dsp_receive_rx(struct avs_dev *adev, u64 header)
{
	struct avs_ipc *ipc = adev->ipc;
	union avs_reply_msg msg = AVS_MSG(header);
	u64 reg;

	reg = readq(avs_sram_addr(adev, AVS_FW_REGS_WINDOW));
	trace_avs_ipc_reply_msg(header, reg);

	ipc->rx.header = header;
	/* Abort copying payload if request processing was unsuccessful. */
	if (!msg.status) {
		/* update size in case of LARGE_CONFIG_GET */
		if (msg.msg_target == AVS_MOD_MSG &&
		    msg.global_msg_type == AVS_MOD_LARGE_CONFIG_GET)
			ipc->rx.size = min_t(u32, AVS_MAILBOX_SIZE,
					     msg.ext.large_config.data_off_size);

		memcpy_fromio(ipc->rx.data, avs_uplink_addr(adev), ipc->rx.size);
		trace_avs_msg_payload(ipc->rx.data, ipc->rx.size);
	}
}

static void avs_dsp_process_notification(struct avs_dev *adev, u64 header)
{
	struct avs_notify_mod_data mod_data;
	union avs_notify_msg msg = AVS_MSG(header);
	size_t data_size = 0;
	void *data = NULL;
	u64 reg;

	reg = readq(avs_sram_addr(adev, AVS_FW_REGS_WINDOW));
	trace_avs_ipc_notify_msg(header, reg);

	/* Ignore spurious notifications until handshake is established. */
	if (!adev->ipc->ready && msg.notify_msg_type != AVS_NOTIFY_FW_READY) {
		dev_dbg(adev->dev, "FW not ready, skip notification: 0x%08x\n", msg.primary);
		return;
	}

	/* Calculate notification payload size. */
	switch (msg.notify_msg_type) {
	case AVS_NOTIFY_FW_READY:
		break;

	case AVS_NOTIFY_PHRASE_DETECTED:
		data_size = sizeof(struct avs_notify_voice_data);
		break;

	case AVS_NOTIFY_RESOURCE_EVENT:
		data_size = sizeof(struct avs_notify_res_data);
		break;

	case AVS_NOTIFY_LOG_BUFFER_STATUS:
	case AVS_NOTIFY_EXCEPTION_CAUGHT:
		break;

	case AVS_NOTIFY_MODULE_EVENT:
		/* To know the total payload size, header needs to be read first. */
		memcpy_fromio(&mod_data, avs_uplink_addr(adev), sizeof(mod_data));
		data_size = sizeof(mod_data) + mod_data.data_size;
		break;

	default:
		dev_info(adev->dev, "unknown notification: 0x%08x\n", msg.primary);
		break;
	}

	if (data_size) {
		data = kmalloc(data_size, GFP_KERNEL);
		if (!data)
			return;

		memcpy_fromio(data, avs_uplink_addr(adev), data_size);
		trace_avs_msg_payload(data, data_size);
	}

	/* Perform notification-specific operations. */
	switch (msg.notify_msg_type) {
	case AVS_NOTIFY_FW_READY:
		dev_dbg(adev->dev, "FW READY 0x%08x\n", msg.primary);
		adev->ipc->ready = true;
		complete(&adev->fw_ready);
		break;

	case AVS_NOTIFY_LOG_BUFFER_STATUS:
		avs_log_buffer_status_locked(adev, &msg);
		break;

	case AVS_NOTIFY_EXCEPTION_CAUGHT:
		avs_dsp_exception_caught(adev, &msg);
		break;

	default:
		break;
	}

	kfree(data);
}

void avs_dsp_process_response(struct avs_dev *adev, u64 header)
{
	struct avs_ipc *ipc = adev->ipc;

	/*
	 * Response may either be solicited - a reply for a request that has
	 * been sent beforehand - or unsolicited (notification).
	 */
	if (avs_msg_is_reply(header)) {
		/* Response processing is invoked from IRQ thread. */
		spin_lock_irq(&ipc->rx_lock);
		avs_dsp_receive_rx(adev, header);
		ipc->rx_completed = true;
		spin_unlock_irq(&ipc->rx_lock);
	} else {
		avs_dsp_process_notification(adev, header);
	}

	complete(&ipc->busy_completion);
}

static bool avs_ipc_is_busy(struct avs_ipc *ipc)
{
	struct avs_dev *adev = to_avs_dev(ipc->dev);
	const struct avs_spec *const spec = adev->spec;
	u32 hipc_rsp;

	hipc_rsp = snd_hdac_adsp_readl(adev, spec->hipc->rsp_offset);
	return hipc_rsp & spec->hipc->rsp_busy_mask;
}

static int avs_ipc_wait_busy_completion(struct avs_ipc *ipc, int timeout)
{
	u32 repeats_left = 128; /* to avoid infinite looping */
	int ret;

again:
	ret = wait_for_completion_timeout(&ipc->busy_completion, msecs_to_jiffies(timeout));

	/* DSP could be unresponsive at this point. */
	if (!ipc->ready)
		return -EPERM;

	if (!ret) {
		if (!avs_ipc_is_busy(ipc))
			return -ETIMEDOUT;
		/*
		 * Firmware did its job, either notification or reply
		 * has been received - now wait until it's processed.
		 */
		wait_for_completion_killable(&ipc->busy_completion);
	}

	/* Ongoing notification's bottom-half may cause early wakeup */
	spin_lock(&ipc->rx_lock);
	if (!ipc->rx_completed) {
		if (repeats_left) {
			/* Reply delayed due to notification. */
			repeats_left--;
			reinit_completion(&ipc->busy_completion);
			spin_unlock(&ipc->rx_lock);
			goto again;
		}

		spin_unlock(&ipc->rx_lock);
		return -ETIMEDOUT;
	}

	spin_unlock(&ipc->rx_lock);
	return 0;
}

static void avs_ipc_msg_init(struct avs_ipc *ipc, struct avs_ipc_msg *reply)
{
	lockdep_assert_held(&ipc->rx_lock);

	ipc->rx.header = 0;
	ipc->rx.size = reply ? reply->size : 0;
	ipc->rx_completed = false;

	reinit_completion(&ipc->done_completion);
	reinit_completion(&ipc->busy_completion);
}

static void avs_dsp_send_tx(struct avs_dev *adev, struct avs_ipc_msg *tx, bool read_fwregs)
{
	const struct avs_spec *const spec = adev->spec;
	u64 reg = ULONG_MAX;

	tx->header |= spec->hipc->req_busy_mask;
	if (read_fwregs)
		reg = readq(avs_sram_addr(adev, AVS_FW_REGS_WINDOW));

	trace_avs_request(tx, reg);

	if (tx->size)
		memcpy_toio(avs_downlink_addr(adev), tx->data, tx->size);
	snd_hdac_adsp_writel(adev, spec->hipc->req_ext_offset, tx->header >> 32);
	snd_hdac_adsp_writel(adev, spec->hipc->req_offset, tx->header & UINT_MAX);
}

static int avs_dsp_do_send_msg(struct avs_dev *adev, struct avs_ipc_msg *request,
			       struct avs_ipc_msg *reply, int timeout, const char *name)
{
	struct avs_ipc *ipc = adev->ipc;
	int ret;

	if (!ipc->ready)
		return -EPERM;

	mutex_lock(&ipc->msg_mutex);

	spin_lock(&ipc->rx_lock);
	avs_ipc_msg_init(ipc, reply);
	avs_dsp_send_tx(adev, request, true);
	spin_unlock(&ipc->rx_lock);

	ret = avs_ipc_wait_busy_completion(ipc, timeout);
	if (ret) {
		if (ret == -ETIMEDOUT) {
			union avs_notify_msg msg = AVS_NOTIFICATION(EXCEPTION_CAUGHT);

			/* Same treatment as on exception, just stack_dump=0. */
			avs_dsp_exception_caught(adev, &msg);
		}
		goto exit;
	}

	ret = ipc->rx.rsp.status;
	/*
	 * If IPC channel is blocked e.g.: due to ongoing recovery,
	 * -EPERM error code is expected and thus it's not an actual error.
	 *
	 * Unsupported IPCs are of no harm either.
	 */
	if (ret == -EPERM || ret == AVS_IPC_NOT_SUPPORTED)
		dev_dbg(adev->dev, "%s (0x%08x 0x%08x) failed: %d\n",
			name, request->glb.primary, request->glb.ext.val, ret);
	else if (ret)
		dev_err(adev->dev, "%s (0x%08x 0x%08x) failed: %d\n",
			name, request->glb.primary, request->glb.ext.val, ret);

	if (reply) {
		reply->header = ipc->rx.header;
		reply->size = ipc->rx.size;
		if (reply->data && ipc->rx.size)
			memcpy(reply->data, ipc->rx.data, reply->size);
	}

exit:
	mutex_unlock(&ipc->msg_mutex);
	return ret;
}

static int avs_dsp_send_msg_sequence(struct avs_dev *adev, struct avs_ipc_msg *request,
				     struct avs_ipc_msg *reply, int timeout, bool wake_d0i0,
				     bool schedule_d0ix, const char *name)
{
	int ret;

	trace_avs_d0ix("wake", wake_d0i0, request->header);
	if (wake_d0i0) {
		ret = avs_dsp_wake_d0i0(adev, request);
		if (ret)
			return ret;
	}

	ret = avs_dsp_do_send_msg(adev, request, reply, timeout, name);
	if (ret)
		return ret;

	trace_avs_d0ix("schedule", schedule_d0ix, request->header);
	if (schedule_d0ix)
		avs_dsp_schedule_d0ix(adev, request);

	return 0;
}

int avs_dsp_send_msg_timeout(struct avs_dev *adev, struct avs_ipc_msg *request,
			     struct avs_ipc_msg *reply, int timeout, const char *name)
{
	bool wake_d0i0 = avs_dsp_op(adev, d0ix_toggle, request, true);
	bool schedule_d0ix = avs_dsp_op(adev, d0ix_toggle, request, false);

	return avs_dsp_send_msg_sequence(adev, request, reply, timeout, wake_d0i0, schedule_d0ix,
					 name);
}

int avs_dsp_send_msg(struct avs_dev *adev, struct avs_ipc_msg *request,
		     struct avs_ipc_msg *reply, const char *name)
{
	return avs_dsp_send_msg_timeout(adev, request, reply, adev->ipc->default_timeout_ms, name);
}

int avs_dsp_send_pm_msg_timeout(struct avs_dev *adev, struct avs_ipc_msg *request,
				struct avs_ipc_msg *reply, int timeout, bool wake_d0i0,
				const char *name)
{
	return avs_dsp_send_msg_sequence(adev, request, reply, timeout, wake_d0i0, false, name);
}

int avs_dsp_send_pm_msg(struct avs_dev *adev, struct avs_ipc_msg *request,
			struct avs_ipc_msg *reply, bool wake_d0i0, const char *name)
{
	return avs_dsp_send_pm_msg_timeout(adev, request, reply, adev->ipc->default_timeout_ms,
					   wake_d0i0, name);
}

static int avs_dsp_do_send_rom_msg(struct avs_dev *adev, struct avs_ipc_msg *request, int timeout,
				   const char *name)
{
	struct avs_ipc *ipc = adev->ipc;
	int ret;

	mutex_lock(&ipc->msg_mutex);

	spin_lock(&ipc->rx_lock);
	avs_ipc_msg_init(ipc, NULL);
	/*
	 * with hw still stalled, memory windows may not be
	 * configured properly so avoid accessing SRAM
	 */
	avs_dsp_send_tx(adev, request, false);
	spin_unlock(&ipc->rx_lock);

	/* ROM messages must be sent before main core is unstalled */
	ret = avs_dsp_op(adev, stall, AVS_MAIN_CORE_MASK, false);
	if (!ret) {
		ret = wait_for_completion_timeout(&ipc->done_completion, msecs_to_jiffies(timeout));
		ret = ret ? 0 : -ETIMEDOUT;
	}
	if (ret)
		dev_err(adev->dev, "%s (0x%08x 0x%08x) failed: %d\n",
			name, request->glb.primary, request->glb.ext.val, ret);

	mutex_unlock(&ipc->msg_mutex);

	return ret;
}

int avs_dsp_send_rom_msg_timeout(struct avs_dev *adev, struct avs_ipc_msg *request, int timeout,
				 const char *name)
{
	return avs_dsp_do_send_rom_msg(adev, request, timeout, name);
}

int avs_dsp_send_rom_msg(struct avs_dev *adev, struct avs_ipc_msg *request, const char *name)
{
	return avs_dsp_send_rom_msg_timeout(adev, request, adev->ipc->default_timeout_ms, name);
}

void avs_dsp_interrupt_control(struct avs_dev *adev, bool enable)
{
	const struct avs_spec *const spec = adev->spec;
	u32 value, mask;

	/*
	 * No particular bit setting order. All of these are required
	 * to have a functional SW <-> FW communication.
	 */
	value = enable ? AVS_ADSP_ADSPIC_IPC : 0;
	snd_hdac_adsp_updatel(adev, AVS_ADSP_REG_ADSPIC, AVS_ADSP_ADSPIC_IPC, value);

	mask = AVS_ADSP_HIPCCTL_DONE | AVS_ADSP_HIPCCTL_BUSY;
	value = enable ? mask : 0;
	snd_hdac_adsp_updatel(adev, spec->hipc->ctl_offset, mask, value);
}

int avs_ipc_init(struct avs_ipc *ipc, struct device *dev)
{
	ipc->rx.data = devm_kzalloc(dev, AVS_MAILBOX_SIZE, GFP_KERNEL);
	if (!ipc->rx.data)
		return -ENOMEM;

	ipc->dev = dev;
	ipc->ready = false;
	ipc->default_timeout_ms = AVS_IPC_TIMEOUT_MS;
	INIT_WORK(&ipc->recovery_work, avs_dsp_recovery_work);
	INIT_DELAYED_WORK(&ipc->d0ix_work, avs_dsp_d0ix_work);
	init_completion(&ipc->done_completion);
	init_completion(&ipc->busy_completion);
	spin_lock_init(&ipc->rx_lock);
	mutex_init(&ipc->msg_mutex);

	return 0;
}

void avs_ipc_block(struct avs_ipc *ipc)
{
	ipc->ready = false;
	cancel_work_sync(&ipc->recovery_work);
	cancel_delayed_work_sync(&ipc->d0ix_work);
	ipc->in_d0ix = false;
}
