BMC/Intel-BMC/linux.git/drivers/s390/cio, branch dev-5.2

s390/qdio: add sanity checks to the fast-requeue path

2019-08-16T08:11:04+00:00

[ Upstream commit a6ec414a4dd529eeac5c3ea51c661daba3397108 ] If the device driver were to send out a full queue's worth of SBALs, current code would end up discovering the last of those SBALs as PRIMED and erroneously skip the SIGA-w. This immediately stalls the queue. Add a check to not attempt fast-requeue in this case. While at it also make sure that the state of the previous SBAL was successfully extracted before inspecting it. Signed-off-by: Julian Wiedmann Reviewed-by: Jens Remus Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

vfio-ccw: Don't call cp_free if we are processing a channel program

2019-08-16T08:10:58+00:00

[ Upstream commit f4c9939433bd396d0b08e803b2b880a9d02682b9 ] There is a small window where it's possible that we could be working on an interrupt (queued in the workqueue) and setting up a channel program (i.e allocating memory, pinning pages, translating address). This can lead to allocating and freeing the channel program at the same time and can cause memory corruption. Let's not call cp_free if we are currently processing a channel program. The only way we know for sure that we don't have a thread setting up a channel program is when the state is set to VFIO_CCW_STATE_CP_PENDING. Fixes: d5afd5d135c8 ("vfio-ccw: add handling for async channel instructions") Signed-off-by: Farhan Ali Reviewed-by: Cornelia Huck Message-Id: <62e87bf67b38dc8d5760586e7c96d400db854ebe.1562854091.git.alifm@linux.ibm.com> Reviewed-by: Eric Farman Signed-off-by: Cornelia Huck Signed-off-by: Sasha Levin

vfio-ccw: Set pa_nr to 0 if memory allocation fails for pa_iova_pfn

2019-08-16T08:10:58+00:00

[ Upstream commit c1ab69268d124ebdbb3864580808188ccd3ea355 ] So we don't call try to call vfio_unpin_pages() incorrectly. Fixes: 0a19e61e6d4c ("vfio: ccw: introduce channel program interfaces") Signed-off-by: Farhan Ali Reviewed-by: Eric Farman Reviewed-by: Cornelia Huck Message-Id: <33a89467ad6369196ae6edf820cbcb1e2d8d050c.1562854091.git.alifm@linux.ibm.com> Signed-off-by: Cornelia Huck Signed-off-by: Sasha Levin

s390/qdio: handle PENDING state for QEBSM devices

2019-07-26T07:10:23+00:00

[ Upstream commit 04310324c6f482921c071444833e70fe861b73d9 ] When a CQ-enabled device uses QEBSM for SBAL state inspection, get_buf_states() can return the PENDING state for an Output Queue. get_outbound_buffer_frontier() isn't prepared for this, and any PENDING buffer will permanently stall all further completion processing on this Queue. This isn't a concern for non-QEBSM devices, as get_buf_states() for such devices will manually turn PENDING buffers into EMPTY ones. Fixes: 104ea556ee7f ("qdio: support asynchronous delivery of storage blocks") Signed-off-by: Julian Wiedmann Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/qdio: don't touch the dsci in tiqdio_add_input_queues()

2019-07-21T07:00:43+00:00

commit ac6639cd3db607d386616487902b4cc1850a7be5 upstream. Current code sets the dsci to 0x00000080. Which doesn't make any sense, as the indicator area is located in the _left-most_ byte. Worse: if the dsci is the _shared_ indicator, this potentially clears the indication of activity for a _different_ device. tiqdio_thinint_handler() will then have no reason to call that device's IRQ handler, and the device ends up stalling. Fixes: d0c9d4a89fff ("[S390] qdio: set correct bit in dsci") Cc: Signed-off-by: Julian Wiedmann Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/qdio: (re-)initialize tiqdio list entries

2019-07-21T07:00:43+00:00

commit e54e4785cb5cb4896cf4285964aeef2125612fb2 upstream. When tiqdio_remove_input_queues() removes a queue from the tiq_list as part of qdio_shutdown(), it doesn't re-initialize the queue's list entry and the prev/next pointers go stale. If a subsequent qdio_establish() fails while sending the ESTABLISH cmd, it calls qdio_shutdown() again in QDIO_IRQ_STATE_ERR state and tiqdio_remove_input_queues() will attempt to remove the queue entry a second time. This dereferences the stale pointers, and bad things ensue. Fix this by re-initializing the list entry after removing it from the list. For good practice also initialize the list entry when the queue is first allocated, and remove the quirky checks that papered over this omission. Note that prior to commit e521813468f7 ("s390/qdio: fix access to uninitialized qdio_q fields"), these checks were bogus anyway. setup_queues_misc() clears the whole queue struct, and thus needs to re-init the prev/next pointers as well. Fixes: 779e6e1c724d ("[S390] qdio: new qdio driver.") Cc: Signed-off-by: Julian Wiedmann Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

vfio-ccw: Destroy kmem cache region on module exit

2019-06-13T13:52:28+00:00

Free the vfio_ccw_cmd_region on module exit. Fixes: d5afd5d135c8 ("vfio-ccw: add handling for async channel instructions") Signed-off-by: Farhan Ali Message-Id: Signed-off-by: Cornelia Huck Signed-off-by: Heiko Carstens

s390/qdio: optimize state inspection of HW-owned SBALs

2019-05-08T13:01:23+00:00

When get_buf_states() gets called with count > 1, it scans the corresponding number of SBAL states until it encounters a mismatch. But when these SBALs are in a HW-owned state, the callers don't actually care _how many_ such SBALs are on the queue. If we can't process the first SBAL, we can't process any of the following SBALs either. So when the first SBAL is HW-owned, skip the scan of the remaining SBALs and thus save some CPU time. Signed-off-by: Julian Wiedmann Reviewed-by: Jens Remus Signed-off-by: Martin Schwidefsky

s390/qdio: use get_buf_state() in debug_get_buf_state()

2019-05-08T13:01:23+00:00

For a 1-SBAL state inspection, use the corresponding helper. No functional change, just reducing the number of immediate callers to get_buf_states(). Signed-off-by: Julian Wiedmann Reviewed-by: Jens Remus Signed-off-by: Martin Schwidefsky

s390/qdio: allow to scan all Output SBALs in one go

2019-05-08T13:01:23+00:00

Old code restricted the number of inspected SBALs to QDIO_MAX_BUFFERS_PER_Q - 1, as otherwise the first_to_check and first_to_kick cursors could overlap. Subsequent code would then assume that there was no progress on the queue, when in fact _all_ SBALs on the queue were ready-to-process. This limitation no longer applies, so allow the queue-scan code to inspect all SBALs on the queue. Note that qeth requires an additional patch ("s390/qeth: stop/wake TX queues based on their fill level"), to avoid potential queue stalls when all 128 SBALs are reported as ready-to-process. Signed-off-by: Julian Wiedmann Signed-off-by: Martin Schwidefsky