[PATCH v2 09/49] IB/hfi1: add completion queue processing

Mike Marciniszyn
2015-06-15T13:26:47Z

drivers/infiniband/hw/hfi1/cq.c | 559 +++++++++++++++++++++++++++++++++++++++
1 file changed, 559 insertions(+)
create mode 100644 drivers/infiniband/hw/hfi1/cq.c

diff --git a/drivers/infiniband/hw/hfi1/cq.c b/drivers/infiniband/hw/hfi1/cq.c
new file mode 100644
index 0000000..b0be03a
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/cq.c
@@ -0,0 +1,559 @@
+/*
+ *
+ * This file is provided under a dual BSD/GPLv2 license. When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * - Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/kthread.h>
+
+#include "verbs.h"
+#include "hfi.h"
+
+/**
+ * hfi1_cq_enter - add a new entry to the completion queue
+ * @cq: completion queue
+ * @entry: work completion entry to add
+ * @sig: true if @entry is a solicited entry
+ *
+ * This may be called with qp->s_lock held.
+ */
+void hfi1_cq_enter(struct hfi1_cq *cq, struct ib_wc *entry, int solicited)
+{
+ struct hfi1_cq_wc *wc;
+ unsigned long flags;
+ u32 head;
+ u32 next;
+
+ spin_lock_irqsave(&cq->lock, flags);
+
+ /*
+ * Note that the head pointer might be writable by user processes.
+ * Take care to verify it is a sane value.
+ */
+ wc = cq->queue;
+ head = wc->head;
+ if (head >= (unsigned) cq->ibcq.cqe) {
+ head = cq->ibcq.cqe;
+ next = 0;
+ } else
+ next = head + 1;
+ if (unlikely(next == wc->tail)) {
+ spin_unlock_irqrestore(&cq->lock, flags);
+ if (cq->ibcq.event_handler) {
+ struct ib_event ev;
+
+ ev.device = cq->ibcq.device;
+ ev.element.cq = &cq->ibcq;
+ ev.event = IB_EVENT_CQ_ERR;
+ cq->ibcq.event_handler(&ev, cq->ibcq.cq_context);
+ }
+ return;
+ }
+ if (cq->ip) {
+ wc->uqueue[head].wr_id = entry->wr_id;
+ wc->uqueue[head].status = entry->status;
+ wc->uqueue[head].opcode = entry->opcode;
+ wc->uqueue[head].vendor_err = entry->vendor_err;
+ wc->uqueue[head].byte_len = entry->byte_len;
+ wc->uqueue[head].ex.imm_data =
+ (__u32 __force)entry->ex.imm_data;
+ wc->uqueue[head].qp_num = entry->qp->qp_num;
+ wc->uqueue[head].src_qp = entry->src_qp;
+ wc->uqueue[head].wc_flags = entry->wc_flags;
+ wc->uqueue[head].pkey_index = entry->pkey_index;
+ wc->uqueue[head].slid = entry->slid;
+ wc->uqueue[head].sl = entry->sl;
+ wc->uqueue[head].dlid_path_bits = entry->dlid_path_bits;
+ wc->uqueue[head].port_num = entry->port_num;
+ /* Make sure entry is written before the head index. */
+ smp_wmb();
+ } else
+ wc->kqueue[head] = *entry;
+ wc->head = next;
+
+ if (cq->notify == IB_CQ_NEXT_COMP ||
+ (cq->notify == IB_CQ_SOLICITED &&
+ (solicited || entry->status != IB_WC_SUCCESS))) {
+ struct kthread_worker *worker;
+ /*
+ * This will cause send_complete() to be called in
+ * another thread.
+ */
+ smp_read_barrier_depends(); /* see hfi1_cq_exit */
+ worker = cq->dd->worker;
+ if (likely(worker)) {
+ cq->notify = IB_CQ_NONE;
+ cq->triggered++;
+ queue_kthread_work(worker, &cq->comptask);
+ }
+ }
+
+ spin_unlock_irqrestore(&cq->lock, flags);
+}
+
+/**
+ * hfi1_poll_cq - poll for work completion entries
+ * @ibcq: the completion queue to poll
+ * @num_entries: the maximum number of entries to return
+ * @entry: pointer to array where work completions are placed
+ *
+ * Returns the number of completion entries polled.
+ *
+ * This may be called from interrupt context. Also called by ib_poll_cq()
+ * in the generic verbs code.
+ */
+int hfi1_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
+{
+ struct hfi1_cq *cq = to_icq(ibcq);
+ struct hfi1_cq_wc *wc;
+ unsigned long flags;
+ int npolled;
+ u32 tail;
+
+ /* The kernel can only poll a kernel completion queue */
+ if (cq->ip) {
+ npolled = -EINVAL;
+ goto bail;
+ }
+
+ spin_lock_irqsave(&cq->lock, flags);
+
+ wc = cq->queue;
+ tail = wc->tail;
+ if (tail > (u32) cq->ibcq.cqe)
+ tail = (u32) cq->ibcq.cqe;
+ for (npolled = 0; npolled < num_entries; ++npolled, ++entry) {
+ if (tail == wc->head)
+ break;
+ /* The kernel doesn't need a RMB since it has the lock. */
+ *entry = wc->kqueue[tail];
+ if (tail >= cq->ibcq.cqe)
+ tail = 0;
+ else
+ tail++;
+ }
+ wc->tail = tail;
+
+ spin_unlock_irqrestore(&cq->lock, flags);
+
+bail:
+ return npolled;
+}
+
+static void send_complete(struct kthread_work *work)
+{
+ struct hfi1_cq *cq = container_of(work, struct hfi1_cq, comptask);
+
+ /*
+ * The completion handler will most likely rearm the notification
+ * and poll for all pending entries. If a new completion entry
+ * is added while we are in this routine, queue_work()
+ * won't call us again until we return so we check triggered to
+ * see if we need to call the handler again.
+ */
+ for (;;) {
+ u8 triggered = cq->triggered;
+
+ /*
+ * IPoIB connected mode assumes the callback is from a
+ * soft IRQ. We simulate this by blocking "bottom halves".
+ * See the implementation for ipoib_cm_handle_tx_wc(),
+ * netif_tx_lock_bh() and netif_tx_lock().
+ */
+ local_bh_disable();
+ cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
+ local_bh_enable();
+
+ if (cq->triggered == triggered)
+ return;
+ }
+}
+
+/**
+ * hfi1_create_cq - create a completion queue
+ * @ibdev: the device this completion queue is attached to
+ * @entries: the minimum size of the completion queue
+ * @context: unused by the driver
+ * @udata: user data for libibverbs.so
+ *
+ * Returns a pointer to the completion queue or negative errno values
+ * for failure.
+ *
+ * Called by ib_create_cq() in the generic verbs code.
+ */
+struct ib_cq *hfi1_create_cq(
+ struct ib_device *ibdev,
+ const struct ib_cq_init_attr *attr,
+ struct ib_ucontext *context,
+ struct ib_udata *udata)
+{
+ struct hfi1_ibdev *dev = to_idev(ibdev);
+ struct hfi1_cq *cq;
+ struct hfi1_cq_wc *wc;
+ struct ib_cq *ret;
+ u32 sz;
+ unsigned int entries = attr->cqe;
+
+ if (entries < 1 || entries > hfi1_max_cqes) {
+ ret = ERR_PTR(-EINVAL);
+ goto done;
+ }
+
+ /* Allocate the completion queue structure. */
+ cq = kmalloc(sizeof(*cq), GFP_KERNEL);
+ if (!cq) {
+ ret = ERR_PTR(-ENOMEM);
+ goto done;
+ }
+
+ /*
+ * Allocate the completion queue entries and head/tail pointers.
+ * This is allocated separately so that it can be resized and
+ * also mapped into user space.
+ * We need to use vmalloc() in order to support mmap and large
+ * numbers of entries.
+ */
+ sz = sizeof(*wc);
+ if (udata && udata->outlen >= sizeof(__u64))
+ sz += sizeof(struct ib_uverbs_wc) * (entries + 1);
+ else
+ sz += sizeof(struct ib_wc) * (entries + 1);
+ wc = vmalloc_user(sz);
+ if (!wc) {
+ ret = ERR_PTR(-ENOMEM);
+ goto bail_cq;
+ }
+
+ /*
+ * Return the address of the WC as the offset to mmap.
+ * See hfi1_mmap() for details.
+ */
+ if (udata && udata->outlen >= sizeof(__u64)) {
+ int err;
+
+ cq->ip = hfi1_create_mmap_info(dev, sz, context, wc);
+ if (!cq->ip) {
+ ret = ERR_PTR(-ENOMEM);
+ goto bail_wc;
+ }
+
+ err = ib_copy_to_udata(udata, &cq->ip->offset,
+ sizeof(cq->ip->offset));
+ if (err) {
+ ret = ERR_PTR(err);
+ goto bail_ip;
+ }
+ } else
+ cq->ip = NULL;
+
+ spin_lock(&dev->n_cqs_lock);
+ if (dev->n_cqs_allocated == hfi1_max_cqs) {
+ spin_unlock(&dev->n_cqs_lock);
+ ret = ERR_PTR(-ENOMEM);
+ goto bail_ip;
+ }
+
+ dev->n_cqs_allocated++;
+ spin_unlock(&dev->n_cqs_lock);
+
+ if (cq->ip) {
+ spin_lock_irq(&dev->pending_lock);
+ list_add(&cq->ip->pending_mmaps, &dev->pending_mmaps);
+ spin_unlock_irq(&dev->pending_lock);
+ }
+
+ /*
+ * ib_create_cq() will initialize cq->ibcq except for cq->ibcq.cqe.
+ * The number of entries should be >= the number requested or return
+ * an error.
+ */
+ cq->dd = dd_from_dev(dev);
+ cq->ibcq.cqe = entries;
+ cq->notify = IB_CQ_NONE;
+ cq->triggered = 0;
+ spin_lock_init(&cq->lock);
+ init_kthread_work(&cq->comptask, send_complete);
+ wc->head = 0;
+ wc->tail = 0;
+ cq->queue = wc;
+
+ ret = &cq->ibcq;
+
+ goto done;
+
+bail_ip:
+ kfree(cq->ip);
+bail_wc:
+ vfree(wc);
+bail_cq:
+ kfree(cq);
+done:
+ return ret;
+}
+
+/**
+ * hfi1_destroy_cq - destroy a completion queue
+ * @ibcq: the completion queue to destroy.
+ *
+ * Returns 0 for success.
+ *
+ * Called by ib_destroy_cq() in the generic verbs code.
+ */
+int hfi1_destroy_cq(struct ib_cq *ibcq)
+{
+ struct hfi1_ibdev *dev = to_idev(ibcq->device);
+ struct hfi1_cq *cq = to_icq(ibcq);
+
+ flush_kthread_work(&cq->comptask);
+ spin_lock(&dev->n_cqs_lock);
+ dev->n_cqs_allocated--;
+ spin_unlock(&dev->n_cqs_lock);
+ if (cq->ip)
+ kref_put(&cq->ip->ref, hfi1_release_mmap_info);
+ else
+ vfree(cq->queue);
+ kfree(cq);
+
+ return 0;
+}
+
+/**
+ * hfi1_req_notify_cq - change the notification type for a completion queue
+ * @ibcq: the completion queue
+ * @notify_flags: the type of notification to request
+ *
+ * Returns 0 for success.
+ *
+ * This may be called from interrupt context. Also called by
+ * ib_req_notify_cq() in the generic verbs code.
+ */
+int hfi1_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags notify_flags)
+{
+ struct hfi1_cq *cq = to_icq(ibcq);
+ unsigned long flags;
+ int ret = 0;
+
+ spin_lock_irqsave(&cq->lock, flags);
+ /*
+ * Don't change IB_CQ_NEXT_COMP to IB_CQ_SOLICITED but allow
+ * any other transitions (see C11-31 and C11-32 in ch. 11.4.2.2).
+ */
+ if (cq->notify != IB_CQ_NEXT_COMP)
+ cq->notify = notify_flags & IB_CQ_SOLICITED_MASK;
+
+ if ((notify_flags & IB_CQ_REPORT_MISSED_EVENTS) &&
+ cq->queue->head != cq->queue->tail)
+ ret = 1;
+
+ spin_unlock_irqrestore(&cq->lock, flags);
+
+ return ret;
+}
+
+/**
+ * hfi1_resize_cq - change the size of the CQ
+ * @ibcq: the completion queue
+ *
+ * Returns 0 for success.
+ */
+int hfi1_resize_cq(struct ib_cq *ibcq, int cqe, struct ib_udata *udata)
+{
+ struct hfi1_cq *cq = to_icq(ibcq);
+ struct hfi1_cq_wc *old_wc;
+ struct hfi1_cq_wc *wc;
+ u32 head, tail, n;
+ int ret;
+ u32 sz;
+
+ if (cqe < 1 || cqe > hfi1_max_cqes) {
+ ret = -EINVAL;
+ goto bail;
+ }
+
+ /*
+ * Need to use vmalloc() if we want to support large #s of entries.
+ */
+ sz = sizeof(*wc);
+ if (udata && udata->outlen >= sizeof(__u64))
+ sz += sizeof(struct ib_uverbs_wc) * (cqe + 1);
+ else
+ sz += sizeof(struct ib_wc) * (cqe + 1);
+ wc = vmalloc_user(sz);
+ if (!wc) {
+ ret = -ENOMEM;
+ goto bail;
+ }
+
+ /* Check that we can write the offset to mmap. */
+ if (udata && udata->outlen >= sizeof(__u64)) {
+ __u64 offset = 0;
+
+ ret = ib_copy_to_udata(udata, &offset, sizeof(offset));
+ if (ret)
+ goto bail_free;
+ }
+
+ spin_lock_irq(&cq->lock);
+ /*
+ * Make sure head and tail are sane since they
+ * might be user writable.
+ */
+ old_wc = cq->queue;
+ head = old_wc->head;
+ if (head > (u32) cq->ibcq.cqe)
+ head = (u32) cq->ibcq.cqe;
+ tail = old_wc->tail;
+ if (tail > (u32) cq->ibcq.cqe)
+ tail = (u32) cq->ibcq.cqe;
+ if (head < tail)
+ n = cq->ibcq.cqe + 1 + head - tail;
+ else
+ n = head - tail;
+ if (unlikely((u32)cqe < n)) {
+ ret = -EINVAL;
+ goto bail_unlock;
+ }
+ for (n = 0; tail != head; n++) {
+ if (cq->ip)
+ wc->uqueue[n] = old_wc->uqueue[tail];
+ else
+ wc->kqueue[n] = old_wc->kqueue[tail];
+ if (tail == (u32) cq->ibcq.cqe)
+ tail = 0;
+ else
+ tail++;
+ }
+ cq->ibcq.cqe = cqe;
+ wc->head = n;
+ wc->tail = 0;
+ cq->queue = wc;
+ spin_unlock_irq(&cq->lock);
+
+ vfree(old_wc);
+
+ if (cq->ip) {
+ struct hfi1_ibdev *dev = to_idev(ibcq->device);
+ struct hfi1_mmap_info *ip = cq->ip;
+
+ hfi1_update_mmap_info(dev, ip, sz, wc);
+
+ /*
+ * Return the offset to mmap.
+ * See hfi1_mmap() for details.
+ */
+ if (udata && udata->outlen >= sizeof(__u64)) {
+ ret = ib_copy_to_udata(udata, &ip->offset,
+ sizeof(ip->offset));
+ if (ret)
+ goto bail;
+ }
+
+ spin_lock_irq(&dev->pending_lock);
+ if (list_empty(&ip->pending_mmaps))
+ list_add(&ip->pending_mmaps, &dev->pending_mmaps);
+ spin_unlock_irq(&dev->pending_lock);
+ }
+
+ ret = 0;
+ goto bail;
+
+bail_unlock:
+ spin_unlock_irq(&cq->lock);
+bail_free:
+ vfree(wc);
+bail:
+ return ret;
+}
+
+int hfi1_cq_init(struct hfi1_devdata *dd)
+{
+ int ret = 0;
+ int cpu;
+ struct task_struct *task;
+
+ if (dd->worker)
+ return 0;
+ dd->worker = kzalloc(sizeof(*dd->worker), GFP_KERNEL);
+ if (!dd->worker)
+ return -ENOMEM;
+ init_kthread_worker(dd->worker);
+ task = kthread_create_on_node(
+ kthread_worker_fn,
+ dd->worker,
+ dd->assigned_node_id,
+ "hfi1_cq%d", dd->unit);
+ if (IS_ERR(task))
+ goto task_fail;
+ cpu = cpumask_first(cpumask_of_node(dd->assigned_node_id));
+ kthread_bind(task, cpu);
+ wake_up_process(task);
+out:
+ return ret;
+task_fail:
+ ret = PTR_ERR(task);
+ kfree(dd->worker);
+ dd->worker = NULL;
+ goto out;
+}
+
+void hfi1_cq_exit(struct hfi1_devdata *dd)
+{
+ struct kthread_worker *worker;
+
+ worker = dd->worker;
+ if (!worker)
+ return;
+ /* blocks future queuing from send_complete() */
+ dd->worker = NULL;
+ smp_wmb(); /* See hfi1_cq_enter */
+ flush_kthread_worker(worker);
+ kthread_stop(worker->task);
+ kfree(worker);