[PATCH] IB/mthca: Add SRQ implementation

Add mthca support for shared receive queues (SRQs),
including userspace SRQs.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 591 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/mthca/mthca_srq.c b/drivers/infiniband/hw/mthca/mthca_srq.c
new file mode 100644
index 00000000000..75cd2d84ef1
--- /dev/null
+++ b/drivers/infiniband/hw/mthca/mthca_srq.c
@@ -0,0 +1,591 @@
+/*
+ * Copyright (c) 2005 Cisco Systems. 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.
+ *
+ * $Id: mthca_srq.c 3047 2005-08-10 03:59:35Z roland $
+ */
+
+#include "mthca_dev.h"
+#include "mthca_cmd.h"
+#include "mthca_memfree.h"
+#include "mthca_wqe.h"
+
+enum {
+	MTHCA_MAX_DIRECT_SRQ_SIZE = 4 * PAGE_SIZE
+};
+
+struct mthca_tavor_srq_context {
+	__be64 wqe_base_ds;	/* low 6 bits is descriptor size */
+	__be32 state_pd;
+	__be32 lkey;
+	__be32 uar;
+	__be32 wqe_cnt;
+	u32    reserved[2];
+};
+
+struct mthca_arbel_srq_context {
+	__be32 state_logsize_srqn;
+	__be32 lkey;
+	__be32 db_index;
+	__be32 logstride_usrpage;
+	__be64 wqe_base;
+	__be32 eq_pd;
+	__be16 limit_watermark;
+	__be16 wqe_cnt;
+	u16    reserved1;
+	__be16 wqe_counter;
+	u32    reserved2[3];
+};
+
+static void *get_wqe(struct mthca_srq *srq, int n)
+{
+	if (srq->is_direct)
+		return srq->queue.direct.buf + (n << srq->wqe_shift);
+	else
+		return srq->queue.page_list[(n << srq->wqe_shift) >> PAGE_SHIFT].buf +
+			((n << srq->wqe_shift) & (PAGE_SIZE - 1));
+}
+
+/*
+ * Return a pointer to the location within a WQE that we're using as a
+ * link when the WQE is in the free list.  We use an offset of 4
+ * because in the Tavor case, posting a WQE may overwrite the first
+ * four bytes of the previous WQE.  The offset avoids corrupting our
+ * free list if the WQE has already completed and been put on the free
+ * list when we post the next WQE.
+ */
+static inline int *wqe_to_link(void *wqe)
+{
+	return (int *) (wqe + 4);
+}
+
+static void mthca_tavor_init_srq_context(struct mthca_dev *dev,
+					 struct mthca_pd *pd,
+					 struct mthca_srq *srq,
+					 struct mthca_tavor_srq_context *context)
+{
+	memset(context, 0, sizeof *context);
+
+	context->wqe_base_ds = cpu_to_be64(1 << (srq->wqe_shift - 4));
+	context->state_pd    = cpu_to_be32(pd->pd_num);
+	context->lkey        = cpu_to_be32(srq->mr.ibmr.lkey);
+
+	if (pd->ibpd.uobject)
+		context->uar =
+			cpu_to_be32(to_mucontext(pd->ibpd.uobject->context)->uar.index);
+	else
+		context->uar = cpu_to_be32(dev->driver_uar.index);
+}
+
+static void mthca_arbel_init_srq_context(struct mthca_dev *dev,
+					 struct mthca_pd *pd,
+					 struct mthca_srq *srq,
+					 struct mthca_arbel_srq_context *context)
+{
+	int logsize;
+
+	memset(context, 0, sizeof *context);
+
+	logsize = long_log2(srq->max) + srq->wqe_shift;
+	context->state_logsize_srqn = cpu_to_be32(logsize << 24 | srq->srqn);
+	context->lkey = cpu_to_be32(srq->mr.ibmr.lkey);
+	context->db_index = cpu_to_be32(srq->db_index);
+	context->logstride_usrpage = cpu_to_be32((srq->wqe_shift - 4) << 29);
+	if (pd->ibpd.uobject)
+		context->logstride_usrpage |=
+			cpu_to_be32(to_mucontext(pd->ibpd.uobject->context)->uar.index);
+	else
+		context->logstride_usrpage |= cpu_to_be32(dev->driver_uar.index);
+	context->eq_pd = cpu_to_be32(MTHCA_EQ_ASYNC << 24 | pd->pd_num);
+}
+
+static void mthca_free_srq_buf(struct mthca_dev *dev, struct mthca_srq *srq)
+{
+	mthca_buf_free(dev, srq->max << srq->wqe_shift, &srq->queue,
+		       srq->is_direct, &srq->mr);
+	kfree(srq->wrid);
+}
+
+static int mthca_alloc_srq_buf(struct mthca_dev *dev, struct mthca_pd *pd,
+			       struct mthca_srq *srq)
+{
+	struct mthca_data_seg *scatter;
+	void *wqe;
+	int err;
+	int i;
+
+	if (pd->ibpd.uobject)
+		return 0;
+
+	srq->wrid = kmalloc(srq->max * sizeof (u64), GFP_KERNEL);
+	if (!srq->wrid)
+		return -ENOMEM;
+
+	err = mthca_buf_alloc(dev, srq->max << srq->wqe_shift,
+			      MTHCA_MAX_DIRECT_SRQ_SIZE,
+			      &srq->queue, &srq->is_direct, pd, 1, &srq->mr);
+	if (err) {
+		kfree(srq->wrid);
+		return err;
+	}
+
+	/*
+	 * Now initialize the SRQ buffer so that all of the WQEs are
+	 * linked into the list of free WQEs.  In addition, set the
+	 * scatter list L_Keys to the sentry value of 0x100.
+	 */
+	for (i = 0; i < srq->max; ++i) {
+		wqe = get_wqe(srq, i);
+
+		*wqe_to_link(wqe) = i < srq->max - 1 ? i + 1 : -1;
+
+		for (scatter = wqe + sizeof (struct mthca_next_seg);
+		     (void *) scatter < wqe + (1 << srq->wqe_shift);
+		     ++scatter)
+			scatter->lkey = cpu_to_be32(MTHCA_INVAL_LKEY);
+	}
+
+	return 0;
+}
+
+int mthca_alloc_srq(struct mthca_dev *dev, struct mthca_pd *pd,
+		    struct ib_srq_attr *attr, struct mthca_srq *srq)
+{
+	struct mthca_mailbox *mailbox;
+	u8 status;
+	int ds;
+	int err;
+
+	/* Sanity check SRQ size before proceeding */
+	if (attr->max_wr > 16 << 20 || attr->max_sge > 64)
+		return -EINVAL;
+
+	srq->max      = attr->max_wr;
+	srq->max_gs   = attr->max_sge;
+	srq->last     = NULL;
+	srq->counter  = 0;
+
+	if (mthca_is_memfree(dev))
+		srq->max = roundup_pow_of_two(srq->max + 1);
+
+	ds = min(64UL,
+		 roundup_pow_of_two(sizeof (struct mthca_next_seg) +
+				    srq->max_gs * sizeof (struct mthca_data_seg)));
+	srq->wqe_shift = long_log2(ds);
+
+	srq->srqn = mthca_alloc(&dev->srq_table.alloc);
+	if (srq->srqn == -1)
+		return -ENOMEM;
+
+	if (mthca_is_memfree(dev)) {
+		err = mthca_table_get(dev, dev->srq_table.table, srq->srqn);
+		if (err)
+			goto err_out;
+
+		if (!pd->ibpd.uobject) {
+			srq->db_index = mthca_alloc_db(dev, MTHCA_DB_TYPE_SRQ,
+						       srq->srqn, &srq->db);
+			if (srq->db_index < 0) {
+				err = -ENOMEM;
+				goto err_out_icm;
+			}
+		}
+	}
+
+	mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
+	if (IS_ERR(mailbox)) {
+		err = PTR_ERR(mailbox);
+		goto err_out_db;
+	}
+
+	err = mthca_alloc_srq_buf(dev, pd, srq);
+	if (err)
+		goto err_out_mailbox;
+
+	spin_lock_init(&srq->lock);
+	atomic_set(&srq->refcount, 1);
+	init_waitqueue_head(&srq->wait);
+
+	if (mthca_is_memfree(dev))
+		mthca_arbel_init_srq_context(dev, pd, srq, mailbox->buf);
+	else
+		mthca_tavor_init_srq_context(dev, pd, srq, mailbox->buf);
+
+	err = mthca_SW2HW_SRQ(dev, mailbox, srq->srqn, &status);
+
+	if (err) {
+		mthca_warn(dev, "SW2HW_SRQ failed (%d)\n", err);
+		goto err_out_free_buf;
+	}
+	if (status) {
+		mthca_warn(dev, "SW2HW_SRQ returned status 0x%02x\n",
+			   status);
+		err = -EINVAL;
+		goto err_out_free_buf;
+	}
+
+	spin_lock_irq(&dev->srq_table.lock);
+	if (mthca_array_set(&dev->srq_table.srq,
+			    srq->srqn & (dev->limits.num_srqs - 1),
+			    srq)) {
+		spin_unlock_irq(&dev->srq_table.lock);
+		goto err_out_free_srq;
+	}
+	spin_unlock_irq(&dev->srq_table.lock);
+
+	mthca_free_mailbox(dev, mailbox);
+
+	srq->first_free = 0;
+	srq->last_free  = srq->max - 1;
+
+	return 0;
+
+err_out_free_srq:
+	err = mthca_HW2SW_SRQ(dev, mailbox, srq->srqn, &status);
+	if (err)
+		mthca_warn(dev, "HW2SW_SRQ failed (%d)\n", err);
+	else if (status)
+		mthca_warn(dev, "HW2SW_SRQ returned status 0x%02x\n", status);
+
+err_out_free_buf:
+	if (!pd->ibpd.uobject)
+		mthca_free_srq_buf(dev, srq);
+
+err_out_mailbox:
+	mthca_free_mailbox(dev, mailbox);
+
+err_out_db:
+	if (!pd->ibpd.uobject && mthca_is_memfree(dev))
+		mthca_free_db(dev, MTHCA_DB_TYPE_SRQ, srq->db_index);
+
+err_out_icm:
+	mthca_table_put(dev, dev->srq_table.table, srq->srqn);
+
+err_out:
+	mthca_free(&dev->srq_table.alloc, srq->srqn);
+
+	return err;
+}
+
+void mthca_free_srq(struct mthca_dev *dev, struct mthca_srq *srq)
+{
+	struct mthca_mailbox *mailbox;
+	int err;
+	u8 status;
+
+	mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
+	if (IS_ERR(mailbox)) {
+		mthca_warn(dev, "No memory for mailbox to free SRQ.\n");
+		return;
+	}
+
+	err = mthca_HW2SW_SRQ(dev, mailbox, srq->srqn, &status);
+	if (err)
+		mthca_warn(dev, "HW2SW_SRQ failed (%d)\n", err);
+	else if (status)
+		mthca_warn(dev, "HW2SW_SRQ returned status 0x%02x\n", status);
+
+	spin_lock_irq(&dev->srq_table.lock);
+	mthca_array_clear(&dev->srq_table.srq,
+			  srq->srqn & (dev->limits.num_srqs - 1));
+	spin_unlock_irq(&dev->srq_table.lock);
+
+	atomic_dec(&srq->refcount);
+	wait_event(srq->wait, !atomic_read(&srq->refcount));
+
+	if (!srq->ibsrq.uobject) {
+		mthca_free_srq_buf(dev, srq);
+		if (mthca_is_memfree(dev))
+			mthca_free_db(dev, MTHCA_DB_TYPE_SRQ, srq->db_index);
+	}
+
+	mthca_table_put(dev, dev->srq_table.table, srq->srqn);
+	mthca_free(&dev->srq_table.alloc, srq->srqn);
+	mthca_free_mailbox(dev, mailbox);
+}
+
+void mthca_srq_event(struct mthca_dev *dev, u32 srqn,
+		     enum ib_event_type event_type)
+{
+	struct mthca_srq *srq;
+	struct ib_event event;
+
+	spin_lock(&dev->srq_table.lock);
+	srq = mthca_array_get(&dev->srq_table.srq, srqn & (dev->limits.num_srqs - 1));
+	if (srq)
+		atomic_inc(&srq->refcount);
+	spin_unlock(&dev->srq_table.lock);
+
+	if (!srq) {
+		mthca_warn(dev, "Async event for bogus SRQ %08x\n", srqn);
+		return;
+	}
+
+	if (!srq->ibsrq.event_handler)
+		goto out;
+
+	event.device      = &dev->ib_dev;
+	event.event       = event_type;
+	event.element.srq  = &srq->ibsrq;
+	srq->ibsrq.event_handler(&event, srq->ibsrq.srq_context);
+
+out:
+	if (atomic_dec_and_test(&srq->refcount))
+		wake_up(&srq->wait);
+}
+
+/*
+ * This function must be called with IRQs disabled.
+ */
+void mthca_free_srq_wqe(struct mthca_srq *srq, u32 wqe_addr)
+{
+	int ind;
+
+	ind = wqe_addr >> srq->wqe_shift;
+
+	spin_lock(&srq->lock);
+
+	if (likely(srq->first_free >= 0))
+		*wqe_to_link(get_wqe(srq, srq->last_free)) = ind;
+	else
+		srq->first_free = ind;
+
+	*wqe_to_link(get_wqe(srq, ind)) = -1;
+	srq->last_free = ind;
+
+	spin_unlock(&srq->lock);
+}
+
+int mthca_tavor_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
+			      struct ib_recv_wr **bad_wr)
+{
+	struct mthca_dev *dev = to_mdev(ibsrq->device);
+	struct mthca_srq *srq = to_msrq(ibsrq);
+	unsigned long flags;
+	int err = 0;
+	int first_ind;
+	int ind;
+	int next_ind;
+	int nreq;
+	int i;
+	void *wqe;
+	void *prev_wqe;
+
+	spin_lock_irqsave(&srq->lock, flags);
+
+	first_ind = srq->first_free;
+
+	for (nreq = 0; wr; ++nreq, wr = wr->next) {
+		ind = srq->first_free;
+
+		if (ind < 0) {
+			mthca_err(dev, "SRQ %06x full\n", srq->srqn);
+			err = -ENOMEM;
+			*bad_wr = wr;
+			return nreq;
+		}
+
+		wqe       = get_wqe(srq, ind);
+		next_ind  = *wqe_to_link(wqe);
+		prev_wqe  = srq->last;
+		srq->last = wqe;
+
+		((struct mthca_next_seg *) wqe)->nda_op = 0;
+		((struct mthca_next_seg *) wqe)->ee_nds = 0;
+		/* flags field will always remain 0 */
+
+		wqe += sizeof (struct mthca_next_seg);
+
+		if (unlikely(wr->num_sge > srq->max_gs)) {
+			err = -EINVAL;
+			*bad_wr = wr;
+			srq->last = prev_wqe;
+			return nreq;
+		}
+
+		for (i = 0; i < wr->num_sge; ++i) {
+			((struct mthca_data_seg *) wqe)->byte_count =
+				cpu_to_be32(wr->sg_list[i].length);
+			((struct mthca_data_seg *) wqe)->lkey =
+				cpu_to_be32(wr->sg_list[i].lkey);
+			((struct mthca_data_seg *) wqe)->addr =
+				cpu_to_be64(wr->sg_list[i].addr);
+			wqe += sizeof (struct mthca_data_seg);
+		}
+
+		if (i < srq->max_gs) {
+			((struct mthca_data_seg *) wqe)->byte_count = 0;
+			((struct mthca_data_seg *) wqe)->lkey = cpu_to_be32(MTHCA_INVAL_LKEY);
+			((struct mthca_data_seg *) wqe)->addr = 0;
+		}
+
+		if (likely(prev_wqe)) {
+			((struct mthca_next_seg *) prev_wqe)->nda_op =
+				cpu_to_be32((ind << srq->wqe_shift) | 1);
+			wmb();
+			((struct mthca_next_seg *) prev_wqe)->ee_nds =
+				cpu_to_be32(MTHCA_NEXT_DBD);
+		}
+
+		srq->wrid[ind]  = wr->wr_id;
+		srq->first_free = next_ind;
+	}
+
+	return nreq;
+
+	if (likely(nreq)) {
+		__be32 doorbell[2];
+
+		doorbell[0] = cpu_to_be32(first_ind << srq->wqe_shift);
+		doorbell[1] = cpu_to_be32((srq->srqn << 8) | nreq);
+
+		/*
+		 * Make sure that descriptors are written before
+		 * doorbell is rung.
+		 */
+		wmb();
+
+		mthca_write64(doorbell,
+			      dev->kar + MTHCA_RECEIVE_DOORBELL,
+			      MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
+	}
+
+	spin_unlock_irqrestore(&srq->lock, flags);
+	return err;
+}
+
+int mthca_arbel_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
+			      struct ib_recv_wr **bad_wr)
+{
+	struct mthca_dev *dev = to_mdev(ibsrq->device);
+	struct mthca_srq *srq = to_msrq(ibsrq);
+	unsigned long flags;
+	int err = 0;
+	int ind;
+	int next_ind;
+	int nreq;
+	int i;
+	void *wqe;
+
+	spin_lock_irqsave(&srq->lock, flags);
+
+	for (nreq = 0; wr; ++nreq, wr = wr->next) {
+		ind = srq->first_free;
+
+		if (ind < 0) {
+			mthca_err(dev, "SRQ %06x full\n", srq->srqn);
+			err = -ENOMEM;
+			*bad_wr = wr;
+			return nreq;
+		}
+
+		wqe       = get_wqe(srq, ind);
+		next_ind  = *wqe_to_link(wqe);
+
+		((struct mthca_next_seg *) wqe)->nda_op =
+			cpu_to_be32((next_ind << srq->wqe_shift) | 1);
+		((struct mthca_next_seg *) wqe)->ee_nds = 0;
+		/* flags field will always remain 0 */
+
+		wqe += sizeof (struct mthca_next_seg);
+
+		if (unlikely(wr->num_sge > srq->max_gs)) {
+			err = -EINVAL;
+			*bad_wr = wr;
+			return nreq;
+		}
+
+		for (i = 0; i < wr->num_sge; ++i) {
+			((struct mthca_data_seg *) wqe)->byte_count =
+				cpu_to_be32(wr->sg_list[i].length);
+			((struct mthca_data_seg *) wqe)->lkey =
+				cpu_to_be32(wr->sg_list[i].lkey);
+			((struct mthca_data_seg *) wqe)->addr =
+				cpu_to_be64(wr->sg_list[i].addr);
+			wqe += sizeof (struct mthca_data_seg);
+		}
+
+		if (i < srq->max_gs) {
+			((struct mthca_data_seg *) wqe)->byte_count = 0;
+			((struct mthca_data_seg *) wqe)->lkey = cpu_to_be32(MTHCA_INVAL_LKEY);
+			((struct mthca_data_seg *) wqe)->addr = 0;
+		}
+
+		srq->wrid[ind]  = wr->wr_id;
+		srq->first_free = next_ind;
+	}
+
+	if (likely(nreq)) {
+		srq->counter += nreq;
+
+		/*
+		 * Make sure that descriptors are written before
+		 * we write doorbell record.
+		 */
+		wmb();
+		*srq->db = cpu_to_be32(srq->counter);
+	}
+
+	spin_unlock_irqrestore(&srq->lock, flags);
+	return err;
+}
+
+int __devinit mthca_init_srq_table(struct mthca_dev *dev)
+{
+	int err;
+
+	if (!(dev->mthca_flags & MTHCA_FLAG_SRQ))
+		return 0;
+
+	spin_lock_init(&dev->srq_table.lock);
+
+	err = mthca_alloc_init(&dev->srq_table.alloc,
+			       dev->limits.num_srqs,
+			       dev->limits.num_srqs - 1,
+			       dev->limits.reserved_srqs);
+	if (err)
+		return err;
+
+	err = mthca_array_init(&dev->srq_table.srq,
+			       dev->limits.num_srqs);
+	if (err)
+		mthca_alloc_cleanup(&dev->srq_table.alloc);
+
+	return err;
+}
+
+void __devexit mthca_cleanup_srq_table(struct mthca_dev *dev)
+{
+	if (!(dev->mthca_flags & MTHCA_FLAG_SRQ))
+		return;
+
+	mthca_array_cleanup(&dev->srq_table.srq, dev->limits.num_srqs);
+	mthca_alloc_cleanup(&dev->srq_table.alloc);
+}