kernel/git/stable/linux.git/drivers/s390/net, branch linux-5.12.y

s390/qdio: let driver manage the QAOB

2021-05-12T06:39:44+00:00

[ Upstream commit 396c100472dd63bb1a5389d9dfb25a94943c41c9 ] We are spending way too much effort on qdio-internal bookkeeping for QAOB management & caching, and it's still not robust. Once qdio's TX path has detached the QAOB from a PENDING buffer, we lost all track of it until it shows up in a CQ notification again. So if the device is torn down before that notification arrives, we leak the QAOB. Just have the driver take care of it, and simply pass down a QAOB if they want a TX with async-completion capability. For a buffer in PENDING state that requires the QAOB for final completion, qeth can now also try to recycle the buffer's QAOB rather than unconditionally freeing it. This also eliminates the qdio_outbuf_state array, which was only needed to transfer the aob->user1 tag from the driver to the qdio layer. Signed-off-by: Julian Wiedmann Acked-by: Benjamin Block Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/qeth: fix notification for pending buffers during teardown

2021-03-10T00:14:54+00:00

The cited commit reworked the state machine for pending TX buffers. In qeth_iqd_tx_complete() it turned PENDING into a transient state, and uses NEED_QAOB for buffers that get parked while waiting for their QAOB completion. But it missed to adjust the check in qeth_tx_complete_buf(). So if qeth_tx_complete_pending_bufs() is called during teardown to drain the parked TX buffers, we no longer raise a notification for af_iucv. Instead of updating the checked state, just move this code into qeth_tx_complete_pending_bufs() itself. This also gets rid of the special-case in the common TX completion path. Fixes: 8908f36d20d8 ("s390/qeth: fix af_iucv notification race") Signed-off-by: Julian Wiedmann Signed-off-by: David S. Miller

s390/qeth: schedule TX NAPI on QAOB completion

2021-03-10T00:14:54+00:00

When a QAOB notifies us that a pending TX buffer has been delivered, the actual TX completion processing by qeth_tx_complete_pending_bufs() is done within the context of a TX NAPI instance. We shouldn't rely on this instance being scheduled by some other TX event, but just do it ourselves. qeth_qdio_handle_aob() is called from qeth_poll(), ie. our main NAPI instance. To avoid touching the TX queue's NAPI instance before/after it is (un-)registered, reorder the code in qeth_open() and qeth_stop() accordingly. Fixes: 0da9581ddb0f ("qeth: exploit asynchronous delivery of storage blocks") Signed-off-by: Julian Wiedmann Signed-off-by: David S. Miller

s390/qeth: improve completion of pending TX buffers

2021-03-10T00:14:54+00:00

The current design attaches a pending TX buffer to a custom single-linked list, which is anchored at the buffer's slot on the TX ring. The buffer is then checked for final completion whenever this slot is processed during a subsequent TX NAPI poll cycle. But if there's insufficient traffic on the ring, we might never make enough progress to get back to this ring slot and discover the pending buffer's final TX completion. In particular if this missing TX completion blocks the application from sending further traffic. So convert the custom single-linked list code to a per-queue list_head, and scan this list on every TX NAPI cycle. Fixes: 0da9581ddb0f ("qeth: exploit asynchronous delivery of storage blocks") Signed-off-by: Julian Wiedmann Signed-off-by: David S. Miller

s390/qeth: fix memory leak after failed TX Buffer allocation

2021-03-10T00:14:53+00:00

When qeth_alloc_qdio_queues() fails to allocate one of the buffers that back an Output Queue, the 'out_freeoutqbufs' path will free all previously allocated buffers for this queue. But it misses to free the half-finished queue struct itself. Move the buffer allocation into qeth_alloc_output_queue(), and deal with such errors internally. Fixes: 0da9581ddb0f ("qeth: exploit asynchronous delivery of storage blocks") Signed-off-by: Julian Wiedmann Reviewed-by: Alexandra Winter Signed-off-by: David S. Miller

Merge tag 's390-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2021-02-21T21:40:06+00:00

Pull s390 updates from Vasily Gorbik: - Convert to using the generic entry infrastructure. - Add vdso time namespace support. - Switch s390 and alpha to 64-bit ino_t. As discussed at https://lore.kernel.org/linux-mm/YCV7QiyoweJwvN+m@osiris/ - Get rid of expensive stck (store clock) usages where possible. Utilize cpu alternatives to patch stckf when supported. - Make tod_clock usage less error prone by converting it to a union and rework code which is using it. - Machine check handler fixes and cleanups. - Drop couple of minor inline asm optimizations to fix clang build. - Default configs changes notably to make libvirt happy. - Various changes to rework and improve qdio code. - Other small various fixes and improvements all over the code. * tag 's390-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (68 commits) s390/qdio: remove 'merge_pending' mechanism s390/qdio: improve handling of PENDING buffers for QEBSM devices s390/qdio: rework q->qdio_error indication s390/qdio: inline qdio_kick_handler() s390/time: remove get_tod_clock_ext() s390/crypto: use store_tod_clock_ext() s390/hypfs: use store_tod_clock_ext() s390/debug: use union tod_clock s390/kvm: use union tod_clock s390/vdso: use union tod_clock s390/time: convert tod_clock_base to union s390/time: introduce new store_tod_clock_ext() s390/time: rename store_tod_clock_ext() and use union tod_clock s390/time: introduce union tod_clock s390,alpha: switch to 64-bit ino_t s390: split cleanup_sie s390: use r13 in cleanup_sie as temp register s390: fix kernel asce loading when sie is interrupted s390: add stack for machine check handler s390: use WRITE_ONCE when re-allocating async stack ...

s390/qdio: remove 'merge_pending' mechanism

2021-02-13T16:17:55+00:00

For non-QEBSM devices, get_buf_states() merges PENDING and EMPTY buffers into a single group of finished buffers. To allow the upper-layer driver to differentiate between the two states, qdio_check_pending() looks at each buffer's state again and sets the sbal_state flag to QDIO_OUTBUF_STATE_FLAG_PENDING accordingly. So effectively we're spending overhead on _every_ Output Queue inspection, just to avoid some additional TX completion calls in case a group of buffers has completed with mixed EMPTY / PENDING state. Given that PENDING buffers should rarely occur, this is a bad trade-off. In particular so as the additional checks in get_buf_states() affect _all_ device types (even those that don't use the PENDING state). Rip it all out, and just report the PENDING completions separately as we already do for QEBSM devices. Signed-off-by: Julian Wiedmann Reviewed-by: Benjamin Block Signed-off-by: Vasily Gorbik

s390/qdio: improve handling of PENDING buffers for QEBSM devices

2021-02-13T16:17:55+00:00

For QEBSM devices the 'merge_pending' mechanism in get_buf_states() doesn't apply, and we can actually get SLSB_P_OUTPUT_PENDING returned. So for this case propagating the PENDING state to the driver via the queue's sbal_state doesn't make sense and creates unnecessary overhead. Instead introduce a new QDIO_ERROR_* flag that gets passed to the driver, and triggers the same processing as if the buffers were flagged as QDIO_OUTBUF_STATE_FLAG_PENDING. Signed-off-by: Julian Wiedmann Reviewed-by: Benjamin Block Signed-off-by: Vasily Gorbik

net/af_iucv: don't track individual TX skbs for TRANS_HIPER sockets

2021-01-29T04:36:21+00:00

Stop maintaining the skb_send_q list for TRANS_HIPER sockets. Not only is it extra overhead, but keeping around a list of skb clones means that we later also have to match the ->sk_txnotify() calls against these clones and free them accordingly. The current matching logic (comparing the skbs' shinfo location) is frustratingly fragile, and breaks if the skb's head is mangled in any sort of way while passing from dev_queue_xmit() to the device's HW queue. Also adjust the interface for ->sk_txnotify(), to make clear that we don't actually care about any skb internals. Signed-off-by: Julian Wiedmann Acked-by: Willem de Bruijn Signed-off-by: Jakub Kicinski

s390/qeth: don't fake a TX completion interrupt after TX error

2021-01-29T04:35:58+00:00

When do_qdio() returns with an unexpected error, qeth_flush_buffers() kicks off a recovery action. In such a case there's no point in starting TX completion processing, the device gets torn down anyway. So take a closer look at do_qdio()'s return value, and skip the TX completion processing accordingly. Signed-off-by: Julian Wiedmann Acked-by: Willem de Bruijn Signed-off-by: Jakub Kicinski