firmware: arm_scmi: Refactor message response path

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>

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 5685621..9a8d6bf 100644 (file)
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -739,6 +739,61 @@ static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo,
 }
 
 /**
+ * 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
  *
  * @ph: Pointer to SCMI protocol handle
@@ -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);