wireguard-linux/drivers/s390/cio/qdio_debug.c, branch jd/orphan-parallel

s390/qdio: fix statistics for 128 SBALs

2020-07-20T08:55:18Z

Old code would only scan up to 127 SBALs at once. So the last statistics bucket was set aside to count "discovered 127 SBALs with new work" events. But nowadays we allow to scan all 128 SBALs for Output Queues, and a subsequent patch will introduce the same for Input Queues. So fix up the accounting to use the last bucket only when all 128 SBALs have been discovered with new work. Signed-off-by: Julian Wiedmann Signed-off-by: Heiko Carstens

s390/qdio: reduce SLSB writes during Input Queue processing

2020-06-16T11:44:04Z

Streamline the processing of QDIO Input Queues, and remove some intermittent SLSB updates (no deleting of old ACKs, no redundant transitions through NOT_INIT). Rather than counting ACKs, we now keep track of the whole batch of SBALs that were completed during the current polling cycle. Most completed SBALs stay in their initial state (ie. PRIMED or ERROR), except that the most recent SBAL in each sub-run is ACKed for IRQ reduction. The only logic changes happen in inbound_handle_work(), the other delta is just a renaming of the variables that track the SBAL batch. Note that in particular we don't need to flip the _oldest_ SBAL to an idle state (eg. NOT_INIT or ACKed) as a guard against catching our own tail. Since get_inbound_buffer_frontier() will never scan more than the remaining nr_buf_used SBALs, this scenario just doesn't occur. Signed-off-by: Julian Wiedmann Signed-off-by: Vasily Gorbik

s390/qdio: cleanly split alloc and establish

2020-04-06T11:13:50Z

All that qdio_allocate() actually uses from the init_data is the cdev, and the number of Input and Output Queues. Have the driver pass those as parameters, and defer the init_data processing into qdio_establish(). This includes writing per-device(!) trace entries, and most of the sanity checks. Signed-off-by: Julian Wiedmann Reviewed-by: Benjamin Block Signed-off-by: Vasily Gorbik

Merge tag 's390-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2020-04-04T16:45:50Z

Pull s390 updates from Vasily Gorbik: - Update maintainers. Niklas Schnelle takes over zpci and Vineeth Vijayan common io code. - Extend cpuinfo to include topology information. - Add new extended counters for IBM z15 and sampling buffer allocation rework in perf code. - Add control over zeroing out memory during system restart. - CCA protected key block version 2 support and other fixes/improvements in crypto code. - Convert to new fallthrough; annotations. - Replace zero-length arrays with flexible-arrays. - QDIO debugfs and other small improvements. - Drop 2-level paging support optimization for compat tasks. Varios mm cleanups. - Remove broken and unused hibernate / power management support. - Remove fake numa support which does not bring any benefits. - Exclude offline CPUs from CPU topology masks to be more consistent with other architectures. - Prevent last branching instruction address leaking to userspace. - Other small various fixes and improvements all over the code. * tag 's390-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (57 commits) s390/mm: cleanup init_new_context() callback s390/mm: cleanup virtual memory constants usage s390/mm: remove page table downgrade support s390/qdio: set qdio_irq->cdev at allocation time s390/qdio: remove unused function declarations s390/ccwgroup: remove pm support s390/ap: remove power management code from ap bus and drivers s390/zcrypt: use kvmalloc instead of kmalloc for 256k alloc s390/mm: cleanup arch_get_unmapped_area() and friends s390/ism: remove pm support s390/cio: use fallthrough; s390/vfio: use fallthrough; s390/zcrypt: use fallthrough; s390: use fallthrough; s390/cpum_sf: Fix wrong page count in error message s390/diag: fix display of diagnose call statistics s390/ap: Remove ap device suspend and resume callbacks s390/pci: Improve handling of unset UID s390/pci: Fix zpci_alloc_domain() over allocation s390/qdio: pass ISC as parameter to chsc_sadc() ...

s390/qdio: set qdio_irq->cdev at allocation time

2020-03-27T09:22:48Z

Set up qdio_irq->cdev right when the qdio_irq struct is allocated, so that all subsequent code can rely on this pointer. Then convert two helper functions to not pass a cdev parameter around. Signed-off-by: Julian Wiedmann Reviewed-by: Benjamin Block Signed-off-by: Vasily Gorbik

s390/qdio: extend polling support to multiple queues

2020-03-25T19:07:15Z

When the support for polling drivers was initially added, it only considered Input Queue 0. But as QDIO interrupts are actually for the full device and not a single queue, this doesn't really fit for configurations where multiple Input Queues are used. Rework the qdio code so that interrupts for a polling driver are not split up into actions for each queue. Instead deliver the interrupt as a single event, and let the driver decide which queue needs what action. When re-enabling the QDIO interrupt via qdio_start_irq(), this means that the qdio code needs to (1) put _all_ eligible queues back into a state where they raise IRQs, (2) and afterwards check _all_ eligible queues for new work to bridge the race window. On the qeth side of things (as the only qdio polling driver), we can now add CQ polling support to the main NAPI poll routine. It doesn't consume NAPI budget, and to avoid hogging the CPU we yield control after completing one full queue worth of buffers. The subsequent qdio_start_irq() will check for any additional work, and have us re-schedule the NAPI instance accordingly. Signed-off-by: Julian Wiedmann Acked-by: Heiko Carstens Signed-off-by: David S. Miller

s390/qdio: export SSQD via debugfs

2020-03-06T10:37:41Z

While we print out various SSQD fields at initialization time, having raw & full access to the current SSQD can help with debugging. Signed-off-by: Julian Wiedmann Signed-off-by: Vasily Gorbik

s390/qdio: simplify debugfs code

2020-02-27T15:02:21Z

There's no need for error handling, the debugfs core is smart enough to deal with IS_ERR() internally. This will also keep us from creating the debugfs files if the device directory doesn't exist. Currently (because irq_ptr->debugfs_dev gets set to NULL on error) the files would be placed into the debugfs root - without any association to their parent device. On teardown, use the debugfs_remove_recursive() helper to avoid keeping track of each created file/directory. Signed-off-by: Julian Wiedmann Reviewed-by: Benjamin Block Signed-off-by: Vasily Gorbik

s390/qdio: simplify ACK tracking

2020-02-10T11:49:35Z

Current code uses a 'polling' flag to keep track of whether an Input Queue has any ACKed SBALs. QEBSM devices might have multiple ACKed SBALs, and those are tracked separately with 'ack_count'. By also setting ack_count for non-QEBSM devices (to a fixed value of 1), we can use 'ack_count != 0' as replacement for the polling flag. Signed-off-by: Julian Wiedmann Signed-off-by: Vasily Gorbik

s390/qdio: eliminate queue's last_move cursor

2019-04-10T15:47:26Z

This cursor is used for debugging only. But since commit "s390/qdio: pass up count of ready-to-process SBALs" it effectively duplicates the first_to_check cursor, diverging for just a short moment when get_*_buffer_frontier() updates q->first_to_check. Signed-off-by: Julian Wiedmann Reviewed-by: Jens Remus Signed-off-by: Martin Schwidefsky