--- /dev/null
+/*
+ * Intel SST generic IPC Support
+ *
+ * Copyright (C) 2015, Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/wait.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/kthread.h>
+#include <sound/asound.h>
+
+#include "sst-dsp.h"
+#include "sst-dsp-priv.h"
+#include "sst-ipc.h"
+
+/* IPC message timeout (msecs) */
+#define IPC_TIMEOUT_MSECS 300
+
+#define IPC_EMPTY_LIST_SIZE 8
+
+/* locks held by caller */
+static struct ipc_message *msg_get_empty(struct sst_generic_ipc *ipc)
+{
+ struct ipc_message *msg = NULL;
+
+ if (!list_empty(&ipc->empty_list)) {
+ msg = list_first_entry(&ipc->empty_list, struct ipc_message,
+ list);
+ list_del(&msg->list);
+ }
+
+ return msg;
+}
+
+static int tx_wait_done(struct sst_generic_ipc *ipc,
+ struct ipc_message *msg, void *rx_data)
+{
+ unsigned long flags;
+ int ret;
+
+ /* wait for DSP completion (in all cases atm inc pending) */
+ ret = wait_event_timeout(msg->waitq, msg->complete,
+ msecs_to_jiffies(IPC_TIMEOUT_MSECS));
+
+ spin_lock_irqsave(&ipc->dsp->spinlock, flags);
+ if (ret == 0) {
+ if (ipc->ops.shim_dbg != NULL)
+ ipc->ops.shim_dbg(ipc, "message timeout");
+
+ list_del(&msg->list);
+ ret = -ETIMEDOUT;
+ } else {
+
+ /* copy the data returned from DSP */
+ if (msg->rx_size)
+ memcpy(rx_data, msg->rx_data, msg->rx_size);
+ ret = msg->errno;
+ }
+
+ list_add_tail(&msg->list, &ipc->empty_list);
+ spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
+ return ret;
+}
+
+static int ipc_tx_message(struct sst_generic_ipc *ipc, u64 header,
+ void *tx_data, size_t tx_bytes, void *rx_data,
+ size_t rx_bytes, int wait)
+{
+ struct ipc_message *msg;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ipc->dsp->spinlock, flags);
+
+ msg = msg_get_empty(ipc);
+ if (msg == NULL) {
+ spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
+ return -EBUSY;
+ }
+
+ msg->header = header;
+ msg->tx_size = tx_bytes;
+ msg->rx_size = rx_bytes;
+ msg->wait = wait;
+ msg->errno = 0;
+ msg->pending = false;
+ msg->complete = false;
+
+ if ((tx_bytes) && (ipc->ops.tx_data_copy != NULL))
+ ipc->ops.tx_data_copy(msg, tx_data, tx_bytes);
+
+ list_add_tail(&msg->list, &ipc->tx_list);
+ spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
+
+ queue_kthread_work(&ipc->kworker, &ipc->kwork);
+
+ if (wait)
+ return tx_wait_done(ipc, msg, rx_data);
+ else
+ return 0;
+}
+
+static int msg_empty_list_init(struct sst_generic_ipc *ipc)
+{
+ int i;
+
+ ipc->msg = kzalloc(sizeof(struct ipc_message) *
+ IPC_EMPTY_LIST_SIZE, GFP_KERNEL);
+ if (ipc->msg == NULL)
+ return -ENOMEM;
+
+ for (i = 0; i < IPC_EMPTY_LIST_SIZE; i++) {
+ init_waitqueue_head(&ipc->msg[i].waitq);
+ list_add(&ipc->msg[i].list, &ipc->empty_list);
+ }
+
+ return 0;
+}
+
+static void ipc_tx_msgs(struct kthread_work *work)
+{
+ struct sst_generic_ipc *ipc =
+ container_of(work, struct sst_generic_ipc, kwork);
+ struct ipc_message *msg;
+ unsigned long flags;
+ u64 ipcx;
+
+ spin_lock_irqsave(&ipc->dsp->spinlock, flags);
+
+ if (list_empty(&ipc->tx_list) || ipc->pending) {
+ spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
+ return;
+ }
+
+ /* if the DSP is busy, we will TX messages after IRQ.
+ * also postpone if we are in the middle of procesing completion irq*/
+ ipcx = sst_dsp_shim_read_unlocked(ipc->dsp, SST_IPCX);
+ if (ipcx & (SST_IPCX_BUSY | SST_IPCX_DONE)) {
+ spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
+ return;
+ }
+
+ msg = list_first_entry(&ipc->tx_list, struct ipc_message, list);
+ list_move(&msg->list, &ipc->rx_list);
+
+ if (ipc->ops.tx_msg != NULL)
+ ipc->ops.tx_msg(ipc, msg);
+
+ spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
+}
+
+int sst_ipc_tx_message_wait(struct sst_generic_ipc *ipc, u64 header,
+ void *tx_data, size_t tx_bytes, void *rx_data, size_t rx_bytes)
+{
+ return ipc_tx_message(ipc, header, tx_data, tx_bytes,
+ rx_data, rx_bytes, 1);
+}
+EXPORT_SYMBOL_GPL(sst_ipc_tx_message_wait);
+
+int sst_ipc_tx_message_nowait(struct sst_generic_ipc *ipc, u64 header,
+ void *tx_data, size_t tx_bytes)
+{
+ return ipc_tx_message(ipc, header, tx_data, tx_bytes,
+ NULL, 0, 0);
+}
+EXPORT_SYMBOL_GPL(sst_ipc_tx_message_nowait);
+
+struct ipc_message *sst_ipc_reply_find_msg(struct sst_generic_ipc *ipc,
+ u64 header)
+{
+ struct ipc_message *msg;
+ u64 mask;
+
+ if (ipc->ops.reply_msg_match != NULL)
+ header = ipc->ops.reply_msg_match(header, &mask);
+
+ if (list_empty(&ipc->rx_list)) {
+ dev_err(ipc->dev, "error: rx list empty but received 0x%llx\n",
+ header);
+ return NULL;
+ }
+
+ list_for_each_entry(msg, &ipc->rx_list, list) {
+ if ((msg->header & mask) == header)
+ return msg;
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(sst_ipc_reply_find_msg);
+
+/* locks held by caller */
+void sst_ipc_tx_msg_reply_complete(struct sst_generic_ipc *ipc,
+ struct ipc_message *msg)
+{
+ msg->complete = true;
+
+ if (!msg->wait)
+ list_add_tail(&msg->list, &ipc->empty_list);
+ else
+ wake_up(&msg->waitq);
+}
+EXPORT_SYMBOL_GPL(sst_ipc_tx_msg_reply_complete);
+
+void sst_ipc_drop_all(struct sst_generic_ipc *ipc)
+{
+ struct ipc_message *msg, *tmp;
+ unsigned long flags;
+ int tx_drop_cnt = 0, rx_drop_cnt = 0;
+
+ /* drop all TX and Rx messages before we stall + reset DSP */
+ spin_lock_irqsave(&ipc->dsp->spinlock, flags);
+
+ list_for_each_entry_safe(msg, tmp, &ipc->tx_list, list) {
+ list_move(&msg->list, &ipc->empty_list);
+ tx_drop_cnt++;
+ }
+
+ list_for_each_entry_safe(msg, tmp, &ipc->rx_list, list) {
+ list_move(&msg->list, &ipc->empty_list);
+ rx_drop_cnt++;
+ }
+
+ spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
+
+ if (tx_drop_cnt || rx_drop_cnt)
+ dev_err(ipc->dev, "dropped IPC msg RX=%d, TX=%d\n",
+ tx_drop_cnt, rx_drop_cnt);
+}
+EXPORT_SYMBOL_GPL(sst_ipc_drop_all);
+
+int sst_ipc_init(struct sst_generic_ipc *ipc)
+{
+ int ret;
+
+ INIT_LIST_HEAD(&ipc->tx_list);
+ INIT_LIST_HEAD(&ipc->rx_list);
+ INIT_LIST_HEAD(&ipc->empty_list);
+ init_waitqueue_head(&ipc->wait_txq);
+
+ ret = msg_empty_list_init(ipc);
+ if (ret < 0)
+ return -ENOMEM;
+
+ /* start the IPC message thread */
+ init_kthread_worker(&ipc->kworker);
+ ipc->tx_thread = kthread_run(kthread_worker_fn,
+ &ipc->kworker, "%s",
+ dev_name(ipc->dev));
+ if (IS_ERR(ipc->tx_thread)) {
+ dev_err(ipc->dev, "error: failed to create message TX task\n");
+ ret = PTR_ERR(ipc->tx_thread);
+ kfree(ipc->msg);
+ return ret;
+ }
+
+ init_kthread_work(&ipc->kwork, ipc_tx_msgs);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(sst_ipc_init);
+
+void sst_ipc_fini(struct sst_generic_ipc *ipc)
+{
+ if (ipc->tx_thread)
+ kthread_stop(ipc->tx_thread);
+
+ if (ipc->msg)
+ kfree(ipc->msg);
+}
+EXPORT_SYMBOL_GPL(sst_ipc_fini);
+
+/* Module information */
+MODULE_AUTHOR("Jin Yao");
+MODULE_DESCRIPTION("Intel SST IPC generic");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff