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firmware: arm_scmi: Refactor message response path

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Refactor code path waiting for message responses into a dedicated helper
function.

No functional change.

Link: https://lore.kernel.org/r/20211129191156.29322-4-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
This commit is contained in:
Cristian Marussi 2021-11-29 19:11:43 +00:00 committed by Sudeep Holla
parent 582730b9cb
commit 5a731aebd3
1 changed files with 56 additions and 32 deletions
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88
drivers/firmware/arm_scmi/driver.c
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@ -738,6 +738,61 @@ static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo,
ktime_after(ktime_get(), stop);
}
/**
* scmi_wait_for_message_response - An helper to group all the possible ways of
* waiting for a synchronous message response.
*
* @cinfo: SCMI channel info
* @xfer: Reference to the transfer being waited for.
*
* Chooses waiting strategy (sleep-waiting vs busy-waiting) depending on
* configuration flags like xfer->hdr.poll_completion.
*
* Return: 0 on Success, error otherwise.
*/
static int scmi_wait_for_message_response(struct scmi_chan_info *cinfo,
struct scmi_xfer *xfer)
{
struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
struct device *dev = info->dev;
int ret = 0, timeout_ms = info->desc->max_rx_timeout_ms;
if (xfer->hdr.poll_completion) {
ktime_t stop = ktime_add_ms(ktime_get(), timeout_ms);
spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer, stop));
if (ktime_before(ktime_get(), stop)) {
unsigned long flags;
/*
* Do not fetch_response if an out-of-order delayed
* response is being processed.
*/
spin_lock_irqsave(&xfer->lock, flags);
if (xfer->state == SCMI_XFER_SENT_OK) {
info->desc->ops->fetch_response(cinfo, xfer);
xfer->state = SCMI_XFER_RESP_OK;
}
spin_unlock_irqrestore(&xfer->lock, flags);
} else {
dev_err(dev,
"timed out in resp(caller: %pS) - polling\n",
(void *)_RET_IP_);
ret = -ETIMEDOUT;
}
} else {
/* And we wait for the response. */
if (!wait_for_completion_timeout(&xfer->done,
msecs_to_jiffies(timeout_ms))) {
dev_err(dev, "timed out in resp(caller: %pS)\n",
(void *)_RET_IP_);
ret = -ETIMEDOUT;
}
}
return ret;
}
/**
* do_xfer() - Do one transfer
*
@ -752,7 +807,6 @@ static int do_xfer(const struct scmi_protocol_handle *ph,
struct scmi_xfer *xfer)
{
int ret;
int timeout;
const struct scmi_protocol_instance *pi = ph_to_pi(ph);
struct scmi_info *info = handle_to_scmi_info(pi->handle);
struct device *dev = info->dev;
@ -796,37 +850,7 @@ static int do_xfer(const struct scmi_protocol_handle *ph,
return ret;
}
if (xfer->hdr.poll_completion) {
ktime_t stop = ktime_add_ms(ktime_get(),
info->desc->max_rx_timeout_ms);
spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer, stop));
if (ktime_before(ktime_get(), stop)) {
unsigned long flags;
/*
* Do not fetch_response if an out-of-order delayed
* response is being processed.
*/
spin_lock_irqsave(&xfer->lock, flags);
if (xfer->state == SCMI_XFER_SENT_OK) {
info->desc->ops->fetch_response(cinfo, xfer);
xfer->state = SCMI_XFER_RESP_OK;
}
spin_unlock_irqrestore(&xfer->lock, flags);
} else {
ret = -ETIMEDOUT;
}
} else {
/* And we wait for the response. */
timeout = msecs_to_jiffies(info->desc->max_rx_timeout_ms);
if (!wait_for_completion_timeout(&xfer->done, timeout)) {
dev_err(dev, "timed out in resp(caller: %pS)\n",
(void *)_RET_IP_);
ret = -ETIMEDOUT;
}
}
ret = scmi_wait_for_message_response(cinfo, xfer);
if (!ret && xfer->hdr.status)
ret = scmi_to_linux_errno(xfer->hdr.status);