liquidio: make soft command calls synchronous

1. Add wait_for_sc_completion_timeout() for waiting the response and
   handling common response errors
2. Send sc's synchronously: remove unused callback function,
   and context structure; use wait_for_sc_completion_timeout() to wait
   its response.

Signed-off-by: Weilin Chang <weilin.chang@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 66 insertions, 0 deletions

diff --git a/drivers/net/ethernet/cavium/liquidio/octeon_main.h b/drivers/net/ethernet/cavium/liquidio/octeon_main.h
index c846eec11a45..de2a2290d5de 100644
--- a/drivers/net/ethernet/cavium/liquidio/octeon_main.h
+++ b/drivers/net/ethernet/cavium/liquidio/octeon_main.h
@@ -188,6 +188,72 @@ sleep_timeout_cond(wait_queue_head_t *wait_queue,
 	remove_wait_queue(wait_queue, &we);
 }
 
+/* input parameter:
+ * sc: pointer to a soft request
+ * timeout: milli sec which an application wants to wait for the
+	    response of the request.
+ *          0: the request will wait until its response gets back
+ *	       from the firmware within LIO_SC_MAX_TMO_MS milli sec.
+ *	       It the response does not return within
+ *	       LIO_SC_MAX_TMO_MS milli sec, lio_process_ordered_list()
+ *	       will move the request to zombie response list.
+ *
+ * return value:
+ * 0: got the response from firmware for the sc request.
+ * errno -EINTR: user abort the command.
+ * errno -ETIME: user spefified timeout value has been expired.
+ * errno -EBUSY: the response of the request does not return in
+ *               resonable time (LIO_SC_MAX_TMO_MS).
+ *               the sc wll be move to zombie response list by
+ *               lio_process_ordered_list()
+ *
+ * A request with non-zero return value, the sc->caller_is_done
+ *  will be marked 1.
+ * When getting a request with zero return value, the requestor
+ *  should mark sc->caller_is_done with 1 after examing the
+ *  response of sc.
+ * lio_process_ordered_list() will free the soft command on behalf
+ * of the soft command requestor.
+ * This is to fix the possible race condition of both timeout process
+ * and lio_process_ordered_list()/callback function to free a
+ * sc strucutre.
+ */
+static inline int
+wait_for_sc_completion_timeout(struct octeon_device *oct_dev,
+			       struct octeon_soft_command *sc,
+			       unsigned long timeout)
+{
+	int errno = 0;
+	long timeout_jiff;
+
+	if (timeout)
+		timeout_jiff = msecs_to_jiffies(timeout);
+	else
+		timeout_jiff = MAX_SCHEDULE_TIMEOUT;
+
+	timeout_jiff =
+		wait_for_completion_interruptible_timeout(&sc->complete,
+							  timeout_jiff);
+	if (timeout_jiff == 0) {
+		dev_err(&oct_dev->pci_dev->dev, "%s: sc is timeout\n",
+			__func__);
+		WRITE_ONCE(sc->caller_is_done, true);
+		errno = -ETIME;
+	} else if (timeout_jiff == -ERESTARTSYS) {
+		dev_err(&oct_dev->pci_dev->dev, "%s: sc is interrupted\n",
+			__func__);
+		WRITE_ONCE(sc->caller_is_done, true);
+		errno = -EINTR;
+	} else  if (sc->sc_status == OCTEON_REQUEST_TIMEOUT) {
+		dev_err(&oct_dev->pci_dev->dev, "%s: sc has fatal timeout\n",
+			__func__);
+		WRITE_ONCE(sc->caller_is_done, true);
+		errno = -EBUSY;
+	}
+
+	return errno;
+}
+
 #ifndef ROUNDUP4
 #define ROUNDUP4(val) (((val) + 3) & 0xfffffffc)
 #endif