From: Dave Marquardt <[email protected]> Add ibmvfc_interrupt_async_subq(), an IRQ handler dedicated to asynchronous sub-CRQ events from the adapter. The handler disables the sub-CRQ IRQ and then calls ibmvfc_drain_async_subq() to consume all pending entries before re-enabling interrupts.
Add ibmvfc_next_async_scrq() to traverse the async sub-CRQ ring directly via msgs.async_scrq[], returning a typed struct ibmvfc_async_sub_crq * without the cast that would be needed when going through ibmvfc_next_scrq(). ibmvfc_drain_async_subq() holds the host lock and per-queue q_lock while processing. It loops over available entries via ibmvfc_next_async_scrq(), wrapping each in a struct ibmvfc_async_crq_event and dispatching to ibmvfc_handle_async(), then clears the valid bit and issues a write barrier. After draining, it re-enables the sub-CRQ IRQ and performs one final check for a newly arrived entry to close the IRQ-enable race; if one is found it is processed before exiting the loop. Signed-off-by: Dave Marquardt <[email protected]> Signed-off-by: Tyrel Datwyler <[email protected]> --- drivers/scsi/ibmvscsi/ibmvfc-core.c | 66 +++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) diff --git a/drivers/scsi/ibmvscsi/ibmvfc-core.c b/drivers/scsi/ibmvscsi/ibmvfc-core.c index 87ee19057551..fc69012efccc 100644 --- a/drivers/scsi/ibmvscsi/ibmvfc-core.c +++ b/drivers/scsi/ibmvscsi/ibmvfc-core.c @@ -4385,6 +4385,72 @@ static struct ibmvfc_crq *ibmvfc_next_scrq(struct ibmvfc_queue *scrq) return crq; } +static struct ibmvfc_async_sub_crq *ibmvfc_next_async_scrq(struct ibmvfc_queue *scrq) +{ + struct ibmvfc_async_sub_crq *crq; + + crq = &scrq->msgs.async_scrq[scrq->cur]; + if (crq->valid & 0x80) { + if (++scrq->cur == scrq->size) + scrq->cur = 0; + rmb(); + } else + crq = NULL; + + return crq; +} + +static void ibmvfc_drain_async_subq(struct ibmvfc_queue *scrq) +{ + struct ibmvfc_host *vhost = scrq->vhost; + struct ibmvfc_async_crq_event ae = { + .type = IBMVFC_ASYNC_CRQ_SUB, + }; + struct ibmvfc_async_sub_crq *crq; + unsigned long flags; + int done = 0; + + spin_lock_irqsave(&vhost->host->host_lock, flags); + spin_lock(scrq->q_lock); + while (!done) { + while ((crq = ibmvfc_next_async_scrq(scrq)) != NULL) { + ae.subq = *crq; + ibmvfc_handle_async(&ae, scrq->vhost); + crq->valid = 0; + wmb(); /* complete write */ + } + + ibmvfc_toggle_scrq_irq(scrq, 1); + crq = ibmvfc_next_async_scrq(scrq); + if (crq != NULL) { + ae.subq = *crq; + ibmvfc_toggle_scrq_irq(scrq, 0); + ibmvfc_handle_async(&ae, scrq->vhost); + crq->valid = 0; + wmb(); /* complete write */ + } else + done = 1; + } + spin_unlock(scrq->q_lock); + spin_unlock_irqrestore(&vhost->host->host_lock, flags); +} + +/** + * ibmvfc_interrupt_async_subq - Handle an async event from the adapter + * @irq: interrupt request + * @scrq_instance: async subq + * + **/ +static irqreturn_t __maybe_unused ibmvfc_interrupt_async_subq(int irq, void *scrq_instance) +{ + struct ibmvfc_queue *scrq = (struct ibmvfc_queue *)scrq_instance; + + ibmvfc_toggle_scrq_irq(scrq, 0); + ibmvfc_drain_async_subq(scrq); + + return IRQ_HANDLED; +} + static void ibmvfc_drain_sub_crq(struct ibmvfc_queue *scrq) { struct ibmvfc_crq *crq; -- 2.56.0
