diff options
Diffstat (limited to 'drivers/infiniband/core/cq.c')
| -rw-r--r-- | drivers/infiniband/core/cq.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c new file mode 100644 index 000000000000..a754fc727de5 --- /dev/null +++ b/drivers/infiniband/core/cq.c @@ -0,0 +1,209 @@ +/* + * Copyright (c) 2015 HGST, a Western Digital Company. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ +#include <linux/module.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <rdma/ib_verbs.h> + +/* # of WCs to poll for with a single call to ib_poll_cq */ +#define IB_POLL_BATCH 16 + +/* # of WCs to iterate over before yielding */ +#define IB_POLL_BUDGET_IRQ 256 +#define IB_POLL_BUDGET_WORKQUEUE 65536 + +#define IB_POLL_FLAGS \ + (IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS) + +static int __ib_process_cq(struct ib_cq *cq, int budget) +{ + int i, n, completed = 0; + + while ((n = ib_poll_cq(cq, IB_POLL_BATCH, cq->wc)) > 0) { + for (i = 0; i < n; i++) { + struct ib_wc *wc = &cq->wc[i]; + + if (wc->wr_cqe) + wc->wr_cqe->done(cq, wc); + else + WARN_ON_ONCE(wc->status == IB_WC_SUCCESS); + } + + completed += n; + + if (n != IB_POLL_BATCH || + (budget != -1 && completed >= budget)) + break; + } + + return completed; +} + +/** + * ib_process_direct_cq - process a CQ in caller context + * @cq: CQ to process + * @budget: number of CQEs to poll for + * + * This function is used to process all outstanding CQ entries on a + * %IB_POLL_DIRECT CQ. It does not offload CQ processing to a different + * context and does not ask for completion interrupts from the HCA. + * + * Note: for compatibility reasons -1 can be passed in %budget for unlimited + * polling. Do not use this feature in new code, it will be removed soon. + */ +int ib_process_cq_direct(struct ib_cq *cq, int budget) +{ + WARN_ON_ONCE(cq->poll_ctx != IB_POLL_DIRECT); + + return __ib_process_cq(cq, budget); +} +EXPORT_SYMBOL(ib_process_cq_direct); + +static void ib_cq_completion_direct(struct ib_cq *cq, void *private) +{ + WARN_ONCE(1, "got unsolicited completion for CQ 0x%p\n", cq); +} + +static int ib_poll_handler(struct irq_poll *iop, int budget) +{ + struct ib_cq *cq = container_of(iop, struct ib_cq, iop); + int completed; + + completed = __ib_process_cq(cq, budget); + if (completed < budget) { + irq_poll_complete(&cq->iop); + if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0) + irq_poll_sched(&cq->iop); + } + + return completed; +} + +static void ib_cq_completion_softirq(struct ib_cq *cq, void *private) +{ + irq_poll_sched(&cq->iop); +} + +static void ib_cq_poll_work(struct work_struct *work) +{ + struct ib_cq *cq = container_of(work, struct ib_cq, work); + int completed; + + completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE); + if (completed >= IB_POLL_BUDGET_WORKQUEUE || + ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0) + queue_work(ib_comp_wq, &cq->work); +} + +static void ib_cq_completion_workqueue(struct ib_cq *cq, void *private) +{ + queue_work(ib_comp_wq, &cq->work); +} + +/** + * ib_alloc_cq - allocate a completion queue + * @dev: device to allocate the CQ for + * @private: driver private data, accessible from cq->cq_context + * @nr_cqe: number of CQEs to allocate + * @comp_vector: HCA completion vectors for this CQ + * @poll_ctx: context to poll the CQ from. + * + * This is the proper interface to allocate a CQ for in-kernel users. A + * CQ allocated with this interface will automatically be polled from the + * specified context. The ULP needs must use wr->wr_cqe instead of wr->wr_id + * to use this CQ abstraction. + */ +struct ib_cq *ib_alloc_cq(struct ib_device *dev, void *private, + int nr_cqe, int comp_vector, enum ib_poll_context poll_ctx) +{ + struct ib_cq_init_attr cq_attr = { + .cqe = nr_cqe, + .comp_vector = comp_vector, + }; + struct ib_cq *cq; + int ret = -ENOMEM; + + cq = dev->create_cq(dev, &cq_attr, NULL, NULL); + if (IS_ERR(cq)) + return cq; + + cq->device = dev; + cq->uobject = NULL; + cq->event_handler = NULL; + cq->cq_context = private; + cq->poll_ctx = poll_ctx; + atomic_set(&cq->usecnt, 0); + + cq->wc = kmalloc_array(IB_POLL_BATCH, sizeof(*cq->wc), GFP_KERNEL); + if (!cq->wc) + goto out_destroy_cq; + + switch (cq->poll_ctx) { + case IB_POLL_DIRECT: + cq->comp_handler = ib_cq_completion_direct; + break; + case IB_POLL_SOFTIRQ: + cq->comp_handler = ib_cq_completion_softirq; + + irq_poll_init(&cq->iop, IB_POLL_BUDGET_IRQ, ib_poll_handler); + ib_req_notify_cq(cq, IB_CQ_NEXT_COMP); + break; + case IB_POLL_WORKQUEUE: + cq->comp_handler = ib_cq_completion_workqueue; + INIT_WORK(&cq->work, ib_cq_poll_work); + ib_req_notify_cq(cq, IB_CQ_NEXT_COMP); + break; + default: + ret = -EINVAL; + goto out_free_wc; + } + + return cq; + +out_free_wc: + kfree(cq->wc); +out_destroy_cq: + cq->device->destroy_cq(cq); + return ERR_PTR(ret); +} +EXPORT_SYMBOL(ib_alloc_cq); + +/** + * ib_free_cq - free a completion queue + * @cq: completion queue to free. + */ +void ib_free_cq(struct ib_cq *cq) +{ + int ret; + + if (WARN_ON_ONCE(atomic_read(&cq->usecnt))) + return; + + switch (cq->poll_ctx) { + case IB_POLL_DIRECT: + break; + case IB_POLL_SOFTIRQ: + irq_poll_disable(&cq->iop); + break; + case IB_POLL_WORKQUEUE: + flush_work(&cq->work); + break; + default: + WARN_ON_ONCE(1); + } + + kfree(cq->wc); + ret = cq->device->destroy_cq(cq); + WARN_ON_ONCE(ret); +} +EXPORT_SYMBOL(ib_free_cq); |