// SPDX-License-Identifier: GPL-2.0-only
/*
* Intel SST generic IPC Support
*
* Copyright (C) 2015, Intel Corporation
*/
#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 <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, struct sst_ipc_message *reply)
{
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 (reply) {
reply->header = msg->rx.header;
if (reply->data)
memcpy(reply->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,
struct sst_ipc_message request,
struct sst_ipc_message *reply, 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->tx.header = request.header;
msg->tx.size = request.size;
msg->rx.header = 0;
msg->rx.size = reply ? reply->size : 0;
msg->wait = wait;
msg->errno = 0;
msg->pending = false;
msg->complete = false;
if ((request.size) && (ipc->ops.tx_data_copy != NULL))
ipc->ops.tx_data_copy(msg, request.data, request.size);
list_add_tail(&msg->list, &ipc->tx_list);
schedule_work(&ipc->kwork);
spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
if (wait)
return tx_wait_done(ipc, msg, reply);
else
return 0;
}
static int msg_empty_list_init(struct sst_generic_ipc *ipc)
{
int i;
ipc->msg = kcalloc(IPC_EMPTY_LIST_SIZE, sizeof(struct ipc_message),
GFP_KERNEL);
if (ipc->msg == NULL)
return -ENOMEM;
for (i = 0; i < IPC_EMPTY_LIST_SIZE; i++) {
ipc->msg[i].tx.data = kzalloc(ipc->tx_data_max_size, GFP_KERNEL);
if (ipc->msg[i].tx.data == NULL)
goto free_mem;
ipc->msg[i].rx.data = kzalloc(ipc->rx_data_max_size, GFP_KERNEL);
if (ipc->msg[i].rx.data == NULL) {
kfree(ipc->msg[i].tx.data);
goto free_mem;
}
init_waitqueue_head(&ipc->msg[i].waitq);
list_add(&ipc->msg[i].list, &ipc->empty_list);
}
return 0;
free_mem:
while (i > 0) {
kfree(ipc->msg[i-1].tx.data);
kfree(ipc->msg[i-1].rx.data);
--i;
}
kfree(ipc->msg);
return -ENOMEM;
}
static void ipc_tx_msgs(struct work_struct *work)
{
struct sst_generic_ipc *ipc =
container_of(work, struct sst_generic_ipc, kwork);
struct ipc_message *msg;
spin_lock_irq(&ipc->dsp->spinlock);
while (!list_empty(&ipc->tx_list) && !ipc->pending) {
/* if the DSP is busy, we will TX messages after IRQ.
* also postpone if we are in the middle of processing
* completion irq
*/
if (ipc->ops.is_dsp_busy && ipc->ops.is_dsp_busy(ipc->dsp)) {
dev_dbg(ipc->dev, "ipc_tx_msgs dsp busy\n");
break;
}
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_irq(&ipc->dsp->spinlock);
}
int sst_ipc_tx_message_wait(struct sst_generic_ipc *ipc,
struct sst_ipc_message request, struct sst_ipc_message *reply)
{
int ret;
/*
* DSP maybe in lower power active state, so
* check if the DSP supports DSP lp On method
* if so invoke that before sending IPC
*/
if (ipc->ops.check_dsp_lp_on)
if (ipc->ops.check_dsp_lp_on(ipc->dsp, true))
return -EIO;
ret = ipc_tx_message(ipc, request, reply, 1);
if (ipc->ops.check_dsp_lp_on)
if (ipc->ops.check_dsp_lp_on(ipc->dsp, false))
return -EIO;
return ret;
}
EXPORT_SYMBOL_GPL(sst_ipc_tx_message_wait);
int sst_ipc_tx_message_nowait(struct sst_generic_ipc *ipc,
struct sst_ipc_message request)
{
return ipc_tx_message(ipc, request, NULL, 0);
}
EXPORT_SYMBOL_GPL(sst_ipc_tx_message_nowait);
int sst_ipc_tx_message_nopm(struct sst_generic_ipc *ipc,
struct sst_ipc_message request, struct sst_ipc_message *reply)
{
return ipc_tx_message(ipc, request, reply, 1);
}
EXPORT_SYMBOL_GPL(sst_ipc_tx_message_nopm);
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);
else
mask = (u64)-1;
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->tx.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);
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;
INIT_WORK(&ipc->kwork, ipc_tx_msgs);
return 0;
}
EXPORT_SYMBOL_GPL(sst_ipc_init);
void sst_ipc_fini(struct sst_generic_ipc *ipc)
{
int i;
cancel_work_sync(&ipc->kwork);
if (ipc->msg) {
for (i = 0; i < IPC_EMPTY_LIST_SIZE; i++) {
kfree(ipc->msg[i].tx.data);
kfree(ipc->msg[i].rx.data);
}
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");