s390/qdio: Cleanup error handling to drivers

Various improvements of qdio error reporting to the
upper-layer drivers (qeth, zfcp):

- Split QDIO_ERROR_ACTIVATE_CHECK_CONDITION into:

  QDIO_ERROR_ACTIVATE: qdio termination interrupt
  QDIO_ERROR_GET_BUF_STATE: QIOASSIST eqbs error
  QDIO_ERROR_SET_BUF_STATE: QIOASSIST sqbs error

  Add QDIO_ERROR_FATAL / QDIO_ERROR_TEMPORARY masks
  to ease recovery decision in upper-layer drivers.

- Don't (ab-)use qdio handler errors as return codes
  for do_QDIO but use standard error codes:

  -ENOBUFS: temporary target CC=2 condition
  -EBUSY: unresolved SIGA-W CC=2 busy condition
  -EIO: I/O error (CC=1, CC=3)

- Remove unneeded memory clobber from SIGA-R
- Remove EX_TABLE entry on SIGA-W, we want to see these errors

Reviewed-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 24 insertions, 23 deletions

diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index 35c685c374e9..19902cdc6fac 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -63,7 +63,7 @@ static inline int do_siga_input(unsigned long schid, unsigned int mask,
                 "       ipm     %0\n"
                 "       srl     %0,28\n"
                 : "=d" (cc)
-                : "d" (__fc), "d" (__schid), "d" (__mask) : "cc", "memory");
+                : "d" (__fc), "d" (__schid), "d" (__mask) : "cc");
         return cc;
 }
 
@@ -74,7 +74,7 @@ static inline int do_siga_input(unsigned long schid, unsigned int mask,
  * @bb: busy bit indicator, set only if SIGA-w/wt could not access a buffer
  * @fc: function code to perform
  *
- * Returns cc or QDIO_ERROR_SIGA_ACCESS_EXCEPTION.
+ * Returns condition code.
  * Note: For IQDC unicast queues only the highest priority queue is processed.
  */
 static inline int do_siga_output(unsigned long schid, unsigned long mask,
@@ -85,18 +85,16 @@ static inline int do_siga_output(unsigned long schid, unsigned long mask,
         register unsigned long __schid asm("1") = schid;
         register unsigned long __mask asm("2") = mask;
         register unsigned long __aob asm("3") = aob;
-        int cc = QDIO_ERROR_SIGA_ACCESS_EXCEPTION;
+        int cc;
 
         asm volatile(
                 "       siga    0\n"
-                "0:     ipm     %0\n"
+                "       ipm     %0\n"
                 "       srl     %0,28\n"
-                "1:\n"
-                EX_TABLE(0b, 1b)
-                : "+d" (cc), "+d" (__fc), "+d" (__schid), "+d" (__mask),
-                  "+d" (__aob)
-                : : "cc", "memory");
-        *bb = ((unsigned int) __fc) >> 31;
+                : "=d" (cc), "+d" (__fc), "+d" (__aob)
+                : "d" (__schid), "d" (__mask)
+                : "cc");
+        *bb = __fc >> 31;
         return cc;
 }
 
@@ -167,7 +165,7 @@ again:
 
         DBF_ERROR("%4x EQBS ERROR", SCH_NO(q));
         DBF_ERROR("%3d%3d%2d", count, tmp_count, nr);
-        q->handler(q->irq_ptr->cdev, QDIO_ERROR_ACTIVATE_CHECK_CONDITION,
+        q->handler(q->irq_ptr->cdev, QDIO_ERROR_GET_BUF_STATE,
                    q->nr, q->first_to_kick, count, q->irq_ptr->int_parm);
         return 0;
 }
@@ -215,7 +213,7 @@ again:
 
         DBF_ERROR("%4x SQBS ERROR", SCH_NO(q));
         DBF_ERROR("%3d%3d%2d", count, tmp_count, nr);
-        q->handler(q->irq_ptr->cdev, QDIO_ERROR_ACTIVATE_CHECK_CONDITION,
+        q->handler(q->irq_ptr->cdev, QDIO_ERROR_SET_BUF_STATE,
                    q->nr, q->first_to_kick, count, q->irq_ptr->int_parm);
         return 0;
 }
@@ -313,7 +311,7 @@ static inline int qdio_siga_sync(struct qdio_q *q, unsigned int output,
         cc = do_siga_sync(schid, output, input, fc);
         if (unlikely(cc))
                 DBF_ERROR("%4x SIGA-S:%2d", SCH_NO(q), cc);
-        return cc;
+        return (cc) ? -EIO : 0;
 }
 
 static inline int qdio_siga_sync_q(struct qdio_q *q)
@@ -384,7 +382,7 @@ static inline int qdio_siga_input(struct qdio_q *q)
         cc = do_siga_input(schid, q->mask, fc);
         if (unlikely(cc))
                 DBF_ERROR("%4x SIGA-R:%2d", SCH_NO(q), cc);
-        return cc;
+        return (cc) ? -EIO : 0;
 }
 
 #define qdio_siga_sync_out(q) qdio_siga_sync(q, ~0U, 0)
@@ -443,7 +441,7 @@ static void process_buffer_error(struct qdio_q *q, int count)
         unsigned char state = (q->is_input_q) ? SLSB_P_INPUT_NOT_INIT :
                                         SLSB_P_OUTPUT_NOT_INIT;
 
-        q->qdio_error |= QDIO_ERROR_SLSB_STATE;
+        q->qdio_error = QDIO_ERROR_SLSB_STATE;
 
         /* special handling for no target buffer empty */
         if ((!q->is_input_q &&
@@ -575,7 +573,7 @@ static int qdio_inbound_q_moved(struct qdio_q *q)
 
         bufnr = get_inbound_buffer_frontier(q);
 
-        if ((bufnr != q->last_move) || q->qdio_error) {
+        if (bufnr != q->last_move) {
                 q->last_move = bufnr;
                 if (!is_thinint_irq(q->irq_ptr) && MACHINE_IS_LPAR)
                         q->u.in.timestamp = get_clock();
@@ -863,7 +861,7 @@ static inline int qdio_outbound_q_moved(struct qdio_q *q)
 
         bufnr = get_outbound_buffer_frontier(q);
 
-        if ((bufnr != q->last_move) || q->qdio_error) {
+        if (bufnr != q->last_move) {
                 q->last_move = bufnr;
                 DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "out moved:%1d", q->nr);
                 return 1;
@@ -894,13 +892,16 @@ retry:
                                 goto retry;
                         }
                         DBF_ERROR("%4x cc2 BBC:%1d", SCH_NO(q), q->nr);
-                        cc |= QDIO_ERROR_SIGA_BUSY;
-                } else
+                        cc = -EBUSY;
+                } else {
                         DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "siga-w cc2:%1d", q->nr);
+                        cc = -ENOBUFS;
+                }
                 break;
         case 1:
         case 3:
                 DBF_ERROR("%4x SIGA-W:%1d", SCH_NO(q), cc);
+                cc = -EIO;
                 break;
         }
         if (retries) {
@@ -1090,7 +1091,7 @@ static void qdio_handle_activate_check(struct ccw_device *cdev,
         }
 
         count = sub_buf(q->first_to_check, q->first_to_kick);
-        q->handler(q->irq_ptr->cdev, QDIO_ERROR_ACTIVATE_CHECK_CONDITION,
+        q->handler(q->irq_ptr->cdev, QDIO_ERROR_ACTIVATE,
                    q->nr, q->first_to_kick, count, irq_ptr->int_parm);
 no_handler:
         qdio_set_state(irq_ptr, QDIO_IRQ_STATE_STOPPED);
@@ -1691,7 +1692,7 @@ int do_QDIO(struct ccw_device *cdev, unsigned int callflags,
                       "do%02x b:%02x c:%02x", callflags, bufnr, count);
 
         if (irq_ptr->state != QDIO_IRQ_STATE_ACTIVE)
-                return -EBUSY;
+                return -EIO;
         if (!count)
                 return 0;
         if (callflags & QDIO_FLAG_SYNC_INPUT)
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 8334dadc681d..c146877e8b7b 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -3339,7 +3339,7 @@ static void qeth_flush_buffers(struct qeth_qdio_out_q *queue, int index,
         if (rc) {
                 queue->card->stats.tx_errors += count;
                 /* ignore temporary SIGA errors without busy condition */
-                if (rc == QDIO_ERROR_SIGA_TARGET)
+                if (rc == -ENOBUFS)
                         return;
                 QETH_CARD_TEXT(queue->card, 2, "flushbuf");
                 QETH_CARD_TEXT_(queue->card, 2, " q%d", queue->queue_no);
@@ -3533,7 +3533,7 @@ void qeth_qdio_output_handler(struct ccw_device *ccwdev,
         int i;
 
         QETH_CARD_TEXT(card, 6, "qdouhdl");
-        if (qdio_error & QDIO_ERROR_ACTIVATE_CHECK_CONDITION) {
+        if (qdio_error & QDIO_ERROR_FATAL) {
                 QETH_CARD_TEXT(card, 2, "achkcond");
                 netif_stop_queue(card->dev);
                 qeth_schedule_recovery(card);