Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / infiniband / hw / ipath / ipath_cq.c
diff --git a/kernel/drivers/infiniband/hw/ipath/ipath_cq.c b/kernel/drivers/infiniband/hw/ipath/ipath_cq.c
new file mode 100644 (file)
index 0000000..0416c6c
--- /dev/null
@@ -0,0 +1,478 @@
+/*
+ * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
+ * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     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.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include "ipath_verbs.h"
+
+/**
+ * ipath_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 solicitated entry
+ *
+ * This may be called with qp->s_lock held.
+ */
+void ipath_cq_enter(struct ipath_cq *cq, struct ib_wc *entry, int solicited)
+{
+       struct ipath_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)) {
+               cq->notify = IB_CQ_NONE;
+               cq->triggered++;
+               /*
+                * This will cause send_complete() to be called in
+                * another thread.
+                */
+               tasklet_hi_schedule(&cq->comptask);
+       }
+
+       spin_unlock_irqrestore(&cq->lock, flags);
+
+       if (entry->status != IB_WC_SUCCESS)
+               to_idev(cq->ibcq.device)->n_wqe_errs++;
+}
+
+/**
+ * ipath_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 ipath_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
+{
+       struct ipath_cq *cq = to_icq(ibcq);
+       struct ipath_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(unsigned long data)
+{
+       struct ipath_cq *cq = (struct ipath_cq *)data;
+
+       /*
+        * 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, tasklet_hi_schedule()
+        * 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;
+
+               cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
+
+               if (cq->triggered == triggered)
+                       return;
+       }
+}
+
+/**
+ * ipath_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 InfiniPath driver
+ * @udata: unused by the InfiniPath driver
+ *
+ * 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 *ipath_create_cq(struct ib_device *ibdev, int entries, int comp_vector,
+                             struct ib_ucontext *context,
+                             struct ib_udata *udata)
+{
+       struct ipath_ibdev *dev = to_idev(ibdev);
+       struct ipath_cq *cq;
+       struct ipath_cq_wc *wc;
+       struct ib_cq *ret;
+       u32 sz;
+
+       if (entries < 1 || entries > ib_ipath_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 ipath_mmap() for details.
+        */
+       if (udata && udata->outlen >= sizeof(__u64)) {
+               int err;
+
+               cq->ip = ipath_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 == ib_ipath_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->ibcq.cqe = entries;
+       cq->notify = IB_CQ_NONE;
+       cq->triggered = 0;
+       spin_lock_init(&cq->lock);
+       tasklet_init(&cq->comptask, send_complete, (unsigned long)cq);
+       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;
+}
+
+/**
+ * ipath_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 ipath_destroy_cq(struct ib_cq *ibcq)
+{
+       struct ipath_ibdev *dev = to_idev(ibcq->device);
+       struct ipath_cq *cq = to_icq(ibcq);
+
+       tasklet_kill(&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, ipath_release_mmap_info);
+       else
+               vfree(cq->queue);
+       kfree(cq);
+
+       return 0;
+}
+
+/**
+ * ipath_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 ipath_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags notify_flags)
+{
+       struct ipath_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;
+}
+
+/**
+ * ipath_resize_cq - change the size of the CQ
+ * @ibcq: the completion queue
+ *
+ * Returns 0 for success.
+ */
+int ipath_resize_cq(struct ib_cq *ibcq, int cqe, struct ib_udata *udata)
+{
+       struct ipath_cq *cq = to_icq(ibcq);
+       struct ipath_cq_wc *old_wc;
+       struct ipath_cq_wc *wc;
+       u32 head, tail, n;
+       int ret;
+       u32 sz;
+
+       if (cqe < 1 || cqe > ib_ipath_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 ipath_ibdev *dev = to_idev(ibcq->device);
+               struct ipath_mmap_info *ip = cq->ip;
+
+               ipath_update_mmap_info(dev, ip, sz, wc);
+
+               /*
+                * Return the offset to mmap.
+                * See ipath_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;
+}