![Bart Van Assche](/assets/img/avatar_default.png)
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Steve Wise <swise@opengridcomputing.com> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Steve Wise <swise@opengridcomputing.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
210 lines
5.2 KiB
C
210 lines
5.2 KiB
C
/*
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* Copyright (c) 2015 HGST, a Western Digital Company.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*/
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#include <linux/module.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <rdma/ib_verbs.h>
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/* # of WCs to poll for with a single call to ib_poll_cq */
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#define IB_POLL_BATCH 16
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/* # of WCs to iterate over before yielding */
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#define IB_POLL_BUDGET_IRQ 256
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#define IB_POLL_BUDGET_WORKQUEUE 65536
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#define IB_POLL_FLAGS \
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(IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS)
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static int __ib_process_cq(struct ib_cq *cq, int budget)
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{
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int i, n, completed = 0;
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while ((n = ib_poll_cq(cq, IB_POLL_BATCH, cq->wc)) > 0) {
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for (i = 0; i < n; i++) {
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struct ib_wc *wc = &cq->wc[i];
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if (wc->wr_cqe)
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wc->wr_cqe->done(cq, wc);
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else
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WARN_ON_ONCE(wc->status == IB_WC_SUCCESS);
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}
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completed += n;
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if (n != IB_POLL_BATCH ||
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(budget != -1 && completed >= budget))
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break;
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}
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return completed;
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}
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/**
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* ib_process_direct_cq - process a CQ in caller context
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* @cq: CQ to process
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* @budget: number of CQEs to poll for
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*
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* This function is used to process all outstanding CQ entries on a
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* %IB_POLL_DIRECT CQ. It does not offload CQ processing to a different
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* context and does not ask for completion interrupts from the HCA.
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*
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* Note: do not pass -1 as %budget unless it is guaranteed that the number
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* of completions that will be processed is small.
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*/
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int ib_process_cq_direct(struct ib_cq *cq, int budget)
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{
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WARN_ON_ONCE(cq->poll_ctx != IB_POLL_DIRECT);
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return __ib_process_cq(cq, budget);
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}
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EXPORT_SYMBOL(ib_process_cq_direct);
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static void ib_cq_completion_direct(struct ib_cq *cq, void *private)
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{
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WARN_ONCE(1, "got unsolicited completion for CQ 0x%p\n", cq);
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}
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static int ib_poll_handler(struct irq_poll *iop, int budget)
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{
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struct ib_cq *cq = container_of(iop, struct ib_cq, iop);
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int completed;
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completed = __ib_process_cq(cq, budget);
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if (completed < budget) {
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irq_poll_complete(&cq->iop);
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if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
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irq_poll_sched(&cq->iop);
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}
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return completed;
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}
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static void ib_cq_completion_softirq(struct ib_cq *cq, void *private)
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{
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irq_poll_sched(&cq->iop);
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}
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static void ib_cq_poll_work(struct work_struct *work)
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{
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struct ib_cq *cq = container_of(work, struct ib_cq, work);
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int completed;
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completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE);
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if (completed >= IB_POLL_BUDGET_WORKQUEUE ||
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ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
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queue_work(ib_comp_wq, &cq->work);
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}
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static void ib_cq_completion_workqueue(struct ib_cq *cq, void *private)
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{
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queue_work(ib_comp_wq, &cq->work);
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}
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/**
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* ib_alloc_cq - allocate a completion queue
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* @dev: device to allocate the CQ for
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* @private: driver private data, accessible from cq->cq_context
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* @nr_cqe: number of CQEs to allocate
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* @comp_vector: HCA completion vectors for this CQ
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* @poll_ctx: context to poll the CQ from.
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*
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* This is the proper interface to allocate a CQ for in-kernel users. A
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* CQ allocated with this interface will automatically be polled from the
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* specified context. The ULP must use wr->wr_cqe instead of wr->wr_id
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* to use this CQ abstraction.
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*/
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struct ib_cq *ib_alloc_cq(struct ib_device *dev, void *private,
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int nr_cqe, int comp_vector, enum ib_poll_context poll_ctx)
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{
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struct ib_cq_init_attr cq_attr = {
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.cqe = nr_cqe,
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.comp_vector = comp_vector,
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};
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struct ib_cq *cq;
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int ret = -ENOMEM;
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cq = dev->create_cq(dev, &cq_attr, NULL, NULL);
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if (IS_ERR(cq))
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return cq;
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cq->device = dev;
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cq->uobject = NULL;
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cq->event_handler = NULL;
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cq->cq_context = private;
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cq->poll_ctx = poll_ctx;
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atomic_set(&cq->usecnt, 0);
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cq->wc = kmalloc_array(IB_POLL_BATCH, sizeof(*cq->wc), GFP_KERNEL);
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if (!cq->wc)
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goto out_destroy_cq;
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switch (cq->poll_ctx) {
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case IB_POLL_DIRECT:
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cq->comp_handler = ib_cq_completion_direct;
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break;
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case IB_POLL_SOFTIRQ:
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cq->comp_handler = ib_cq_completion_softirq;
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irq_poll_init(&cq->iop, IB_POLL_BUDGET_IRQ, ib_poll_handler);
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ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
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break;
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case IB_POLL_WORKQUEUE:
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cq->comp_handler = ib_cq_completion_workqueue;
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INIT_WORK(&cq->work, ib_cq_poll_work);
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ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
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break;
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default:
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ret = -EINVAL;
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goto out_free_wc;
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}
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return cq;
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out_free_wc:
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kfree(cq->wc);
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out_destroy_cq:
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cq->device->destroy_cq(cq);
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return ERR_PTR(ret);
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}
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EXPORT_SYMBOL(ib_alloc_cq);
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/**
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* ib_free_cq - free a completion queue
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* @cq: completion queue to free.
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*/
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void ib_free_cq(struct ib_cq *cq)
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{
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int ret;
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if (WARN_ON_ONCE(atomic_read(&cq->usecnt)))
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return;
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switch (cq->poll_ctx) {
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case IB_POLL_DIRECT:
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break;
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case IB_POLL_SOFTIRQ:
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irq_poll_disable(&cq->iop);
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break;
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case IB_POLL_WORKQUEUE:
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flush_work(&cq->work);
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break;
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default:
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WARN_ON_ONCE(1);
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}
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kfree(cq->wc);
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ret = cq->device->destroy_cq(cq);
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WARN_ON_ONCE(ret);
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}
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EXPORT_SYMBOL(ib_free_cq);
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