Revert "Move xen patchset to new version's subdir."

[people/pmueller/ipfire-2.x.git] / src / patches / suse-2.6.27.25 / patches.arch / s390-11-07-qdio_kill_tasklets.patch

diff --git a/src/patches/suse-2.6.27.25/patches.arch/s390-11-07-qdio_kill_tasklets.patch b/src/patches/suse-2.6.27.25/patches.arch/s390-11-07-qdio_kill_tasklets.patch
new file mode 100644 (file)
index 0000000..a21d92d
--- /dev/null
+++ b/src/patches/suse-2.6.27.25/patches.arch/s390-11-07-qdio_kill_tasklets.patch
@@ -0,0 +1,159 @@
+From: Gerald Schaefer <geraldsc@de.ibm.com>
+Subject: qdio: proper kill of qdio tasklets
+References: bnc#484767,LTC#52206
+
+Symptom:     kernel BUG at kernel/softirq.c:392!
+Problem:     The queue tasklets were stopped with tasklet_disable. Although
+             tasklet_disable prevents the tasklet from beeing executed it is
+             still possible that a tasklet is scheduled on a CPU at that point.
+             A following qdio_establish calls tasklet_init which clears the
+             tasklet count and the tasklet state leading to the oops.
+Solution:    Use tasklet_kill instead of tasklet_disbale. Since
+             tasklet_schedule must not be called after tasklet_kill use the
+             QDIO_IRQ_STATE_STOPPED to inidicate that a queue is going down
+             and prevent further tasklet schedules in that case.
+
+Acked-by: John Jolly <jjolly@suse.de>
+---
+ drivers/s390/cio/qdio_main.c    |   35 ++++++++++++++++++++++++-----------
+ drivers/s390/cio/qdio_thinint.c |    8 ++++----
+ 2 files changed, 28 insertions(+), 15 deletions(-)
+
+Index: linux-sles11/drivers/s390/cio/qdio_main.c
+===================================================================
+--- linux-sles11.orig/drivers/s390/cio/qdio_main.c
++++ linux-sles11/drivers/s390/cio/qdio_main.c
+@@ -760,21 +760,17 @@ static void __qdio_outbound_processing(s
+       if (qdio_outbound_q_moved(q))
+               qdio_kick_outbound_handler(q);
+ 
+-      if (queue_type(q) == QDIO_ZFCP_QFMT) {
++      if (queue_type(q) == QDIO_ZFCP_QFMT)
+               if (!pci_out_supported(q) && !qdio_outbound_q_done(q))
+-                      tasklet_schedule(&q->tasklet);
+-              return;
+-      }
++                      goto sched;
+ 
+       /* bail out for HiperSockets unicast queues */
+       if (queue_type(q) == QDIO_IQDIO_QFMT && !multicast_outbound(q))
+               return;
+ 
+       if ((queue_type(q) == QDIO_IQDIO_QFMT) &&
+-          (atomic_read(&q->nr_buf_used)) > QDIO_IQDIO_POLL_LVL) {
+-              tasklet_schedule(&q->tasklet);
+-              return;
+-      }
++          (atomic_read(&q->nr_buf_used)) > QDIO_IQDIO_POLL_LVL)
++              goto sched;
+ 
+       if (q->u.out.pci_out_enabled)
+               return;
+@@ -792,6 +788,12 @@ static void __qdio_outbound_processing(s
+                       qdio_perf_stat_inc(&perf_stats.debug_tl_out_timer);
+               }
+       }
++      return;
++
++sched:
++      if (unlikely(q->irq_ptr->state == QDIO_IRQ_STATE_STOPPED))
++              return;
++      tasklet_schedule(&q->tasklet);
+ }
+ 
+ /* outbound tasklet */
+@@ -804,6 +806,9 @@ void qdio_outbound_processing(unsigned l
+ void qdio_outbound_timer(unsigned long data)
+ {
+       struct qdio_q *q = (struct qdio_q *)data;
++
++      if (unlikely(q->irq_ptr->state == QDIO_IRQ_STATE_STOPPED))
++              return;
+       tasklet_schedule(&q->tasklet);
+ }
+ 
+@@ -845,6 +850,9 @@ static void qdio_int_handler_pci(struct 
+       int i;
+       struct qdio_q *q;
+ 
++      if (unlikely(irq_ptr->state == QDIO_IRQ_STATE_STOPPED))
++              return;
++
+       qdio_perf_stat_inc(&perf_stats.pci_int);
+ 
+       for_each_input_queue(irq_ptr, q, i)
+@@ -1072,11 +1080,11 @@ static void qdio_shutdown_queues(struct 
+       int i;
+ 
+       for_each_input_queue(irq_ptr, q, i)
+-              tasklet_disable(&q->tasklet);
++              tasklet_kill(&q->tasklet);
+ 
+       for_each_output_queue(irq_ptr, q, i) {
+-              tasklet_disable(&q->tasklet);
+               del_timer(&q->u.out.timer);
++              tasklet_kill(&q->tasklet);
+       }
+ }
+ 
+@@ -1107,6 +1115,12 @@ int qdio_shutdown(struct ccw_device *cde
+               return 0;
+       }
+ 
++      /*
++       * Indicate that the device is going down. Scheduling the queue
++       * tasklets is forbidden from here on.
++       */
++      qdio_set_state(irq_ptr, QDIO_IRQ_STATE_STOPPED);
++
+       tiqdio_remove_input_queues(irq_ptr);
+       qdio_shutdown_queues(cdev);
+       qdio_shutdown_debug_entries(irq_ptr, cdev);
+@@ -1526,7 +1540,6 @@ static int handle_outbound(struct qdio_q
+               qdio_perf_stat_inc(&perf_stats.fast_requeue);
+       }
+ out:
+-      /* Fixme: could wait forever if called from process context */
+       tasklet_schedule(&q->tasklet);
+       return rc;
+ }
+Index: linux-sles11/drivers/s390/cio/qdio_thinint.c
+===================================================================
+--- linux-sles11.orig/drivers/s390/cio/qdio_thinint.c
++++ linux-sles11/drivers/s390/cio/qdio_thinint.c
+@@ -101,7 +101,6 @@ void tiqdio_add_input_queues(struct qdio
+               list_add_rcu(&q->entry, &tiq_list);
+       mutex_unlock(&tiq_list_lock);
+       xchg(irq_ptr->dsci, 1);
+-      tasklet_schedule(&tiqdio_tasklet);
+ }
+ 
+ /*
+@@ -159,7 +158,6 @@ static void __tiqdio_inbound_processing(
+        */
+       qdio_check_outbound_after_thinint(q);
+ 
+-again:
+       if (!qdio_inbound_q_moved(q))
+               return;
+ 
+@@ -167,7 +165,8 @@ again:
+ 
+       if (!tiqdio_inbound_q_done(q)) {
+               qdio_perf_stat_inc(&perf_stats.thinint_inbound_loop);
+-              goto again;
++              if (likely(q->irq_ptr->state != QDIO_IRQ_STATE_STOPPED))
++                      tasklet_schedule(&q->tasklet);
+       }
+ 
+       qdio_stop_polling(q);
+@@ -177,7 +176,8 @@ again:
+        */
+       if (!tiqdio_inbound_q_done(q)) {
+               qdio_perf_stat_inc(&perf_stats.thinint_inbound_loop2);
+-              goto again;
++              if (likely(q->irq_ptr->state != QDIO_IRQ_STATE_STOPPED))
++                      tasklet_schedule(&q->tasklet);
+       }
+ }
+