IB/mlx4: Add support for resizing CQs

Signed-off-by: Vladimir Sokolovsky <vlad@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 259 insertions, 33 deletions

diff --git a/drivers/infiniband/hw/mlx4/cq.c b/drivers/infiniband/hw/mlx4/cq.c
index e4fb64b118e3..3557e7edc9b6 100644
--- a/drivers/infiniband/hw/mlx4/cq.c
+++ b/drivers/infiniband/hw/mlx4/cq.c
@@ -93,6 +93,74 @@ int mlx4_ib_modify_cq(struct ib_cq *cq, u16 cq_count, u16 cq_period)
         return mlx4_cq_modify(dev->dev, &mcq->mcq, cq_count, cq_period);
 }
 
+static int mlx4_ib_alloc_cq_buf(struct mlx4_ib_dev *dev, struct mlx4_ib_cq_buf *buf, int nent)
+{
+        int err;
+
+        err = mlx4_buf_alloc(dev->dev, nent * sizeof(struct mlx4_cqe),
+                             PAGE_SIZE * 2, &buf->buf);
+
+        if (err)
+                goto out;
+
+        err = mlx4_mtt_init(dev->dev, buf->buf.npages, buf->buf.page_shift,
+                                    &buf->mtt);
+        if (err)
+                goto err_buf;
+
+        err = mlx4_buf_write_mtt(dev->dev, &buf->mtt, &buf->buf);
+        if (err)
+                goto err_mtt;
+
+        return 0;
+
+err_mtt:
+        mlx4_mtt_cleanup(dev->dev, &buf->mtt);
+
+err_buf:
+        mlx4_buf_free(dev->dev, nent * sizeof(struct mlx4_cqe),
+                              &buf->buf);
+
+out:
+        return err;
+}
+
+static void mlx4_ib_free_cq_buf(struct mlx4_ib_dev *dev, struct mlx4_ib_cq_buf *buf, int cqe)
+{
+        mlx4_buf_free(dev->dev, (cqe + 1) * sizeof(struct mlx4_cqe), &buf->buf);
+}
+
+static int mlx4_ib_get_cq_umem(struct mlx4_ib_dev *dev, struct ib_ucontext *context,
+                               struct mlx4_ib_cq_buf *buf, struct ib_umem **umem,
+                               u64 buf_addr, int cqe)
+{
+        int err;
+
+        *umem = ib_umem_get(context, buf_addr, cqe * sizeof (struct mlx4_cqe),
+                            IB_ACCESS_LOCAL_WRITE);
+        if (IS_ERR(*umem))
+                return PTR_ERR(*umem);
+
+        err = mlx4_mtt_init(dev->dev, ib_umem_page_count(*umem),
+                            ilog2((*umem)->page_size), &buf->mtt);
+        if (err)
+                goto err_buf;
+
+        err = mlx4_ib_umem_write_mtt(dev, &buf->mtt, *umem);
+        if (err)
+                goto err_mtt;
+
+        return 0;
+
+err_mtt:
+        mlx4_mtt_cleanup(dev->dev, &buf->mtt);
+
+err_buf:
+        ib_umem_release(*umem);
+
+        return err;
+}
+
 struct ib_cq *mlx4_ib_create_cq(struct ib_device *ibdev, int entries, int vector,
                                 struct ib_ucontext *context,
                                 struct ib_udata *udata)
@@ -100,7 +168,6 @@ struct ib_cq *mlx4_ib_create_cq(struct ib_device *ibdev, int entries, int vector
         struct mlx4_ib_dev *dev = to_mdev(ibdev);
         struct mlx4_ib_cq *cq;
         struct mlx4_uar *uar;
-        int buf_size;
         int err;
 
         if (entries < 1 || entries > dev->dev->caps.max_cqes)
@@ -112,8 +179,10 @@ struct ib_cq *mlx4_ib_create_cq(struct ib_device *ibdev, int entries, int vector
 
         entries      = roundup_pow_of_two(entries + 1);
         cq->ibcq.cqe = entries - 1;
-        buf_size     = entries * sizeof (struct mlx4_cqe);
+        mutex_init(&cq->resize_mutex);
         spin_lock_init(&cq->lock);
+        cq->resize_buf = NULL;
+        cq->resize_umem = NULL;
 
         if (context) {
                 struct mlx4_ib_create_cq ucmd;
@@ -123,21 +192,10 @@ struct ib_cq *mlx4_ib_create_cq(struct ib_device *ibdev, int entries, int vector
                         goto err_cq;
                 }
 
-                cq->umem = ib_umem_get(context, ucmd.buf_addr, buf_size,
-                                       IB_ACCESS_LOCAL_WRITE);
-                if (IS_ERR(cq->umem)) {
-                        err = PTR_ERR(cq->umem);
-                        goto err_cq;
-                }
-
-                err = mlx4_mtt_init(dev->dev, ib_umem_page_count(cq->umem),
-                                    ilog2(cq->umem->page_size), &cq->buf.mtt);
+                err = mlx4_ib_get_cq_umem(dev, context, &cq->buf, &cq->umem,
+                                          ucmd.buf_addr, entries);
                 if (err)
-                        goto err_buf;
-
-                err = mlx4_ib_umem_write_mtt(dev, &cq->buf.mtt, cq->umem);
-                if (err)
-                        goto err_mtt;
+                        goto err_cq;
 
                 err = mlx4_ib_db_map_user(to_mucontext(context), ucmd.db_addr,
                                           &cq->db);
@@ -155,19 +213,9 @@ struct ib_cq *mlx4_ib_create_cq(struct ib_device *ibdev, int entries, int vector
                 *cq->mcq.set_ci_db = 0;
                 *cq->mcq.arm_db    = 0;
 
-                if (mlx4_buf_alloc(dev->dev, buf_size, PAGE_SIZE * 2, &cq->buf.buf)) {
-                        err = -ENOMEM;
-                        goto err_db;
-                }
-
-                err = mlx4_mtt_init(dev->dev, cq->buf.buf.npages, cq->buf.buf.page_shift,
-                                    &cq->buf.mtt);
+                err = mlx4_ib_alloc_cq_buf(dev, &cq->buf, entries);
                 if (err)
-                        goto err_buf;
-
-                err = mlx4_buf_write_mtt(dev->dev, &cq->buf.mtt, &cq->buf.buf);
-                if (err)
-                        goto err_mtt;
+                        goto err_db;
 
                 uar = &dev->priv_uar;
         }
@@ -195,12 +243,10 @@ err_dbmap:
 err_mtt:
         mlx4_mtt_cleanup(dev->dev, &cq->buf.mtt);
 
-err_buf:
         if (context)
                 ib_umem_release(cq->umem);
         else
-                mlx4_buf_free(dev->dev, entries * sizeof (struct mlx4_cqe),
-                              &cq->buf.buf);
+                mlx4_ib_free_cq_buf(dev, &cq->buf, entries);
 
 err_db:
         if (!context)
@@ -212,6 +258,170 @@ err_cq:
         return ERR_PTR(err);
 }
 
+static int mlx4_alloc_resize_buf(struct mlx4_ib_dev *dev, struct mlx4_ib_cq *cq,
+                                  int entries)
+{
+        int err;
+
+        if (cq->resize_buf)
+                return -EBUSY;
+
+        cq->resize_buf = kmalloc(sizeof *cq->resize_buf, GFP_ATOMIC);
+        if (!cq->resize_buf)
+                return -ENOMEM;
+
+        err = mlx4_ib_alloc_cq_buf(dev, &cq->resize_buf->buf, entries);
+        if (err) {
+                kfree(cq->resize_buf);
+                cq->resize_buf = NULL;
+                return err;
+        }
+
+        cq->resize_buf->cqe = entries - 1;
+
+        return 0;
+}
+
+static int mlx4_alloc_resize_umem(struct mlx4_ib_dev *dev, struct mlx4_ib_cq *cq,
+                                   int entries, struct ib_udata *udata)
+{
+        struct mlx4_ib_resize_cq ucmd;
+        int err;
+
+        if (cq->resize_umem)
+                return -EBUSY;
+
+        if (ib_copy_from_udata(&ucmd, udata, sizeof ucmd))
+                return -EFAULT;
+
+        cq->resize_buf = kmalloc(sizeof *cq->resize_buf, GFP_ATOMIC);
+        if (!cq->resize_buf)
+                return -ENOMEM;
+
+        err = mlx4_ib_get_cq_umem(dev, cq->umem->context, &cq->resize_buf->buf,
+                                  &cq->resize_umem, ucmd.buf_addr, entries);
+        if (err) {
+                kfree(cq->resize_buf);
+                cq->resize_buf = NULL;
+                return err;
+        }
+
+        cq->resize_buf->cqe = entries - 1;
+
+        return 0;
+}
+
+static int mlx4_ib_get_outstanding_cqes(struct mlx4_ib_cq *cq)
+{
+        u32 i;
+
+        i = cq->mcq.cons_index;
+        while (get_sw_cqe(cq, i & cq->ibcq.cqe))
+                ++i;
+
+        return i - cq->mcq.cons_index;
+}
+
+static void mlx4_ib_cq_resize_copy_cqes(struct mlx4_ib_cq *cq)
+{
+        struct mlx4_cqe *cqe;
+        int i;
+
+        i = cq->mcq.cons_index;
+        cqe = get_cqe(cq, i & cq->ibcq.cqe);
+        while ((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) != MLX4_CQE_OPCODE_RESIZE) {
+                memcpy(get_cqe_from_buf(&cq->resize_buf->buf,
+                                        (i + 1) & cq->resize_buf->cqe),
+                        get_cqe(cq, i & cq->ibcq.cqe), sizeof(struct mlx4_cqe));
+                cqe = get_cqe(cq, ++i & cq->ibcq.cqe);
+        }
+        ++cq->mcq.cons_index;
+}
+
+int mlx4_ib_resize_cq(struct ib_cq *ibcq, int entries, struct ib_udata *udata)
+{
+        struct mlx4_ib_dev *dev = to_mdev(ibcq->device);
+        struct mlx4_ib_cq *cq = to_mcq(ibcq);
+        int outst_cqe;
+        int err;
+
+        mutex_lock(&cq->resize_mutex);
+
+        if (entries < 1 || entries > dev->dev->caps.max_cqes) {
+                err = -EINVAL;
+                goto out;
+        }
+
+        entries = roundup_pow_of_two(entries + 1);
+        if (entries == ibcq->cqe + 1) {
+                err = 0;
+                goto out;
+        }
+
+        if (ibcq->uobject) {
+                err = mlx4_alloc_resize_umem(dev, cq, entries, udata);
+                if (err)
+                        goto out;
+        } else {
+                /* Can't be smaller then the number of outstanding CQEs */
+                outst_cqe = mlx4_ib_get_outstanding_cqes(cq);
+                if (entries < outst_cqe + 1) {
+                        err = 0;
+                        goto out;
+                }
+
+                err = mlx4_alloc_resize_buf(dev, cq, entries);
+                if (err)
+                        goto out;
+        }
+
+        err = mlx4_cq_resize(dev->dev, &cq->mcq, entries, &cq->resize_buf->buf.mtt);
+        if (err)
+                goto err_buf;
+
+        if (ibcq->uobject) {
+                cq->buf      = cq->resize_buf->buf;
+                cq->ibcq.cqe = cq->resize_buf->cqe;
+                ib_umem_release(cq->umem);
+                cq->umem     = cq->resize_umem;
+
+                kfree(cq->resize_buf);
+                cq->resize_buf = NULL;
+                cq->resize_umem = NULL;
+        } else {
+                spin_lock_irq(&cq->lock);
+                if (cq->resize_buf) {
+                        mlx4_ib_cq_resize_copy_cqes(cq);
+                        mlx4_ib_free_cq_buf(dev, &cq->buf, cq->ibcq.cqe);
+                        cq->buf      = cq->resize_buf->buf;
+                        cq->ibcq.cqe = cq->resize_buf->cqe;
+
+                        kfree(cq->resize_buf);
+                        cq->resize_buf = NULL;
+                }
+                spin_unlock_irq(&cq->lock);
+        }
+
+        goto out;
+
+err_buf:
+        if (!ibcq->uobject)
+                mlx4_ib_free_cq_buf(dev, &cq->resize_buf->buf,
+                                    cq->resize_buf->cqe);
+
+        kfree(cq->resize_buf);
+        cq->resize_buf = NULL;
+
+        if (cq->resize_umem) {
+                ib_umem_release(cq->resize_umem);
+                cq->resize_umem = NULL;
+        }
+
+out:
+        mutex_unlock(&cq->resize_mutex);
+        return err;
+}
+
 int mlx4_ib_destroy_cq(struct ib_cq *cq)
 {
         struct mlx4_ib_dev *dev = to_mdev(cq->device);
@@ -224,8 +434,7 @@ int mlx4_ib_destroy_cq(struct ib_cq *cq)
                 mlx4_ib_db_unmap_user(to_mucontext(cq->uobject->context), &mcq->db);
                 ib_umem_release(mcq->umem);
         } else {
-                mlx4_buf_free(dev->dev, (cq->cqe + 1) * sizeof (struct mlx4_cqe),
-                              &mcq->buf.buf);
+                mlx4_ib_free_cq_buf(dev, &mcq->buf, cq->cqe + 1);
                 mlx4_ib_db_free(dev, &mcq->db);
         }
 
@@ -332,6 +541,7 @@ static int mlx4_ib_poll_one(struct mlx4_ib_cq *cq,
         u32 g_mlpath_rqpn;
         u16 wqe_ctr;
 
+repoll:
         cqe = next_cqe_sw(cq);
         if (!cqe)
                 return -EAGAIN;
@@ -354,6 +564,22 @@ static int mlx4_ib_poll_one(struct mlx4_ib_cq *cq,
                 return -EINVAL;
         }
 
+        /* Resize CQ in progress */
+        if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) == MLX4_CQE_OPCODE_RESIZE)) {
+                if (cq->resize_buf) {
+                        struct mlx4_ib_dev *dev = to_mdev(cq->ibcq.device);
+
+                        mlx4_ib_free_cq_buf(dev, &cq->buf, cq->ibcq.cqe);
+                        cq->buf      = cq->resize_buf->buf;
+                        cq->ibcq.cqe = cq->resize_buf->cqe;
+
+                        kfree(cq->resize_buf);
+                        cq->resize_buf = NULL;
+                }
+
+                goto repoll;
+        }
+
         if (!*cur_qp ||
             (be32_to_cpu(cqe->my_qpn) & 0xffffff) != (*cur_qp)->mqp.qpn) {
                 /*