IB/mlx5: Add support for resize CQ

Implement resize CQ which is a mandatory verb in mlx5.

Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

6 files changed, 284 insertions, 22 deletions

diff --git a/drivers/infiniband/hw/mlx5/cq.c b/drivers/infiniband/hw/mlx5/cq.c
index b4c122eab484..50b03a8067e5 100644
--- a/drivers/infiniband/hw/mlx5/cq.c
+++ b/drivers/infiniband/hw/mlx5/cq.c
@@ -73,14 +73,24 @@ static void *get_cqe(struct mlx5_ib_cq *cq, int n)
         return get_cqe_from_buf(&cq->buf, n, cq->mcq.cqe_sz);
 }
 
+static u8 sw_ownership_bit(int n, int nent)
+{
+        return (n & nent) ? 1 : 0;
+}
+
 static void *get_sw_cqe(struct mlx5_ib_cq *cq, int n)
 {
         void *cqe = get_cqe(cq, n & cq->ibcq.cqe);
         struct mlx5_cqe64 *cqe64;
 
         cqe64 = (cq->mcq.cqe_sz == 64) ? cqe : cqe + 64;
-        return ((cqe64->op_own & MLX5_CQE_OWNER_MASK) ^
-                !!(n & (cq->ibcq.cqe + 1))) ? NULL : cqe;
+
+        if (likely((cqe64->op_own) >> 4 != MLX5_CQE_INVALID) &&
+            !((cqe64->op_own & MLX5_CQE_OWNER_MASK) ^ !!(n & (cq->ibcq.cqe + 1)))) {
+                return cqe;
+        } else {
+                return NULL;
+        }
 }
 
 static void *next_cqe_sw(struct mlx5_ib_cq *cq)
@@ -351,6 +361,11 @@ static void handle_atomics(struct mlx5_ib_qp *qp, struct mlx5_cqe64 *cqe64,
         qp->sq.last_poll = tail;
 }
 
+static void free_cq_buf(struct mlx5_ib_dev *dev, struct mlx5_ib_cq_buf *buf)
+{
+        mlx5_buf_free(&dev->mdev, &buf->buf);
+}
+
 static int mlx5_poll_one(struct mlx5_ib_cq *cq,
                          struct mlx5_ib_qp **cur_qp,
                          struct ib_wc *wc)
@@ -366,6 +381,7 @@ static int mlx5_poll_one(struct mlx5_ib_cq *cq,
         void *cqe;
         int idx;
 
+repoll:
         cqe = next_cqe_sw(cq);
         if (!cqe)
                 return -EAGAIN;
@@ -379,7 +395,18 @@ static int mlx5_poll_one(struct mlx5_ib_cq *cq,
          */
         rmb();
 
-        /* TBD: resize CQ */
+        opcode = cqe64->op_own >> 4;
+        if (unlikely(opcode == MLX5_CQE_RESIZE_CQ)) {
+                if (likely(cq->resize_buf)) {
+                        free_cq_buf(dev, &cq->buf);
+                        cq->buf = *cq->resize_buf;
+                        kfree(cq->resize_buf);
+                        cq->resize_buf = NULL;
+                        goto repoll;
+                } else {
+                        mlx5_ib_warn(dev, "unexpected resize cqe\n");
+                }
+        }
 
         qpn = ntohl(cqe64->sop_drop_qpn) & 0xffffff;
         if (!*cur_qp || (qpn != (*cur_qp)->ibqp.qp_num)) {
@@ -398,7 +425,6 @@ static int mlx5_poll_one(struct mlx5_ib_cq *cq,
         }
 
         wc->qp  = &(*cur_qp)->ibqp;
-        opcode = cqe64->op_own >> 4;
         switch (opcode) {
         case MLX5_CQE_REQ:
                 wq = &(*cur_qp)->sq;
@@ -503,15 +529,11 @@ static int alloc_cq_buf(struct mlx5_ib_dev *dev, struct mlx5_ib_cq_buf *buf,
                 return err;
 
         buf->cqe_size = cqe_size;
+        buf->nent = nent;
 
         return 0;
 }
 
-static void free_cq_buf(struct mlx5_ib_dev *dev, struct mlx5_ib_cq_buf *buf)
-{
-        mlx5_buf_free(&dev->mdev, &buf->buf);
-}
-
 static int create_cq_user(struct mlx5_ib_dev *dev, struct ib_udata *udata,
                           struct ib_ucontext *context, struct mlx5_ib_cq *cq,
                           int entries, struct mlx5_create_cq_mbox_in **cqb,
@@ -576,16 +598,16 @@ static void destroy_cq_user(struct mlx5_ib_cq *cq, struct ib_ucontext *context)
         ib_umem_release(cq->buf.umem);
 }
 
-static void init_cq_buf(struct mlx5_ib_cq *cq, int nent)
+static void init_cq_buf(struct mlx5_ib_cq *cq, struct mlx5_ib_cq_buf *buf)
 {
         int i;
         void *cqe;
         struct mlx5_cqe64 *cqe64;
 
-        for (i = 0; i < nent; i++) {
-                cqe = get_cqe(cq, i);
-                cqe64 = (cq->buf.cqe_size == 64) ? cqe : cqe + 64;
-                cqe64->op_own = 0xf1;
+        for (i = 0; i < buf->nent; i++) {
+                cqe = get_cqe_from_buf(buf, i, buf->cqe_size);
+                cqe64 = buf->cqe_size == 64 ? cqe : cqe + 64;
+                cqe64->op_own = MLX5_CQE_INVALID << 4;
         }
 }
 
@@ -610,7 +632,7 @@ static int create_cq_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_cq *cq,
         if (err)
                 goto err_db;
 
-        init_cq_buf(cq, entries);
+        init_cq_buf(cq, &cq->buf);
 
         *inlen = sizeof(**cqb) + sizeof(*(*cqb)->pas) * cq->buf.buf.npages;
         *cqb = mlx5_vzalloc(*inlen);
@@ -836,7 +858,7 @@ int mlx5_ib_modify_cq(struct ib_cq *cq, u16 cq_count, u16 cq_period)
         in->ctx.cq_period = cpu_to_be16(cq_period);
         in->ctx.cq_max_count = cpu_to_be16(cq_count);
         in->field_select = cpu_to_be32(fsel);
-        err = mlx5_core_modify_cq(&dev->mdev, &mcq->mcq, in);
+        err = mlx5_core_modify_cq(&dev->mdev, &mcq->mcq, in, sizeof(*in));
         kfree(in);
 
         if (err)
@@ -845,9 +867,235 @@ int mlx5_ib_modify_cq(struct ib_cq *cq, u16 cq_count, u16 cq_period)
         return err;
 }
 
+static int resize_user(struct mlx5_ib_dev *dev, struct mlx5_ib_cq *cq,
+                       int entries, struct ib_udata *udata, int *npas,
+                       int *page_shift, int *cqe_size)
+{
+        struct mlx5_ib_resize_cq ucmd;
+        struct ib_umem *umem;
+        int err;
+        int npages;
+        struct ib_ucontext *context = cq->buf.umem->context;
+
+        if (ib_copy_from_udata(&ucmd, udata, sizeof(ucmd)))
+                return -EFAULT;
+
+        umem = ib_umem_get(context, ucmd.buf_addr, entries * ucmd.cqe_size,
+                           IB_ACCESS_LOCAL_WRITE, 1);
+        if (IS_ERR(umem)) {
+                err = PTR_ERR(umem);
+                return err;
+        }
+
+        mlx5_ib_cont_pages(umem, ucmd.buf_addr, &npages, page_shift,
+                           npas, NULL);
+
+        cq->resize_umem = umem;
+        *cqe_size = ucmd.cqe_size;
+
+        return 0;
+}
+
+static void un_resize_user(struct mlx5_ib_cq *cq)
+{
+        ib_umem_release(cq->resize_umem);
+}
+
+static int resize_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_cq *cq,
+                         int entries, int cqe_size)
+{
+        int err;
+
+        cq->resize_buf = kzalloc(sizeof(*cq->resize_buf), GFP_KERNEL);
+        if (!cq->resize_buf)
+                return -ENOMEM;
+
+        err = alloc_cq_buf(dev, cq->resize_buf, entries, cqe_size);
+        if (err)
+                goto ex;
+
+        init_cq_buf(cq, cq->resize_buf);
+
+        return 0;
+
+ex:
+        kfree(cq->resize_buf);
+        return err;
+}
+
+static void un_resize_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_cq *cq)
+{
+        free_cq_buf(dev, cq->resize_buf);
+        cq->resize_buf = NULL;
+}
+
+static int copy_resize_cqes(struct mlx5_ib_cq *cq)
+{
+        struct mlx5_ib_dev *dev = to_mdev(cq->ibcq.device);
+        struct mlx5_cqe64 *scqe64;
+        struct mlx5_cqe64 *dcqe64;
+        void *start_cqe;
+        void *scqe;
+        void *dcqe;
+        int ssize;
+        int dsize;
+        int i;
+        u8 sw_own;
+
+        ssize = cq->buf.cqe_size;
+        dsize = cq->resize_buf->cqe_size;
+        if (ssize != dsize) {
+                mlx5_ib_warn(dev, "resize from different cqe size is not supported\n");
+                return -EINVAL;
+        }
+
+        i = cq->mcq.cons_index;
+        scqe = get_sw_cqe(cq, i);
+        scqe64 = ssize == 64 ? scqe : scqe + 64;
+        start_cqe = scqe;
+        if (!scqe) {
+                mlx5_ib_warn(dev, "expected cqe in sw ownership\n");
+                return -EINVAL;
+        }
+
+        while ((scqe64->op_own >> 4) != MLX5_CQE_RESIZE_CQ) {
+                dcqe = get_cqe_from_buf(cq->resize_buf,
+                                        (i + 1) & (cq->resize_buf->nent),
+                                        dsize);
+                dcqe64 = dsize == 64 ? dcqe : dcqe + 64;
+                sw_own = sw_ownership_bit(i + 1, cq->resize_buf->nent);
+                memcpy(dcqe, scqe, dsize);
+                dcqe64->op_own = (dcqe64->op_own & ~MLX5_CQE_OWNER_MASK) | sw_own;
+
+                ++i;
+                scqe = get_sw_cqe(cq, i);
+                scqe64 = ssize == 64 ? scqe : scqe + 64;
+                if (!scqe) {
+                        mlx5_ib_warn(dev, "expected cqe in sw ownership\n");
+                        return -EINVAL;
+                }
+
+                if (scqe == start_cqe) {
+                        pr_warn("resize CQ failed to get resize CQE, CQN 0x%x\n",
+                                cq->mcq.cqn);
+                        return -ENOMEM;
+                }
+        }
+        ++cq->mcq.cons_index;
+        return 0;
+}
+
 int mlx5_ib_resize_cq(struct ib_cq *ibcq, int entries, struct ib_udata *udata)
 {
-        return -ENOSYS;
+        struct mlx5_ib_dev *dev = to_mdev(ibcq->device);
+        struct mlx5_ib_cq *cq = to_mcq(ibcq);
+        struct mlx5_modify_cq_mbox_in *in;
+        int err;
+        int npas;
+        int page_shift;
+        int inlen;
+        int uninitialized_var(cqe_size);
+        unsigned long flags;
+
+        if (!(dev->mdev.caps.flags & MLX5_DEV_CAP_FLAG_RESIZE_CQ)) {
+                pr_info("Firmware does not support resize CQ\n");
+                return -ENOSYS;
+        }
+
+        if (entries < 1)
+                return -EINVAL;
+
+        entries = roundup_pow_of_two(entries + 1);
+        if (entries > dev->mdev.caps.max_cqes + 1)
+                return -EINVAL;
+
+        if (entries == ibcq->cqe + 1)
+                return 0;
+
+        mutex_lock(&cq->resize_mutex);
+        if (udata) {
+                err = resize_user(dev, cq, entries, udata, &npas, &page_shift,
+                                  &cqe_size);
+        } else {
+                cqe_size = 64;
+                err = resize_kernel(dev, cq, entries, cqe_size);
+                if (!err) {
+                        npas = cq->resize_buf->buf.npages;
+                        page_shift = cq->resize_buf->buf.page_shift;
+                }
+        }
+
+        if (err)
+                goto ex;
+
+        inlen = sizeof(*in) + npas * sizeof(in->pas[0]);
+        in = mlx5_vzalloc(inlen);
+        if (!in) {
+                err = -ENOMEM;
+                goto ex_resize;
+        }
+
+        if (udata)
+                mlx5_ib_populate_pas(dev, cq->resize_umem, page_shift,
+                                     in->pas, 0);
+        else
+                mlx5_fill_page_array(&cq->resize_buf->buf, in->pas);
+
+        in->field_select = cpu_to_be32(MLX5_MODIFY_CQ_MASK_LOG_SIZE  |
+                                       MLX5_MODIFY_CQ_MASK_PG_OFFSET |
+                                       MLX5_MODIFY_CQ_MASK_PG_SIZE);
+        in->ctx.log_pg_sz = page_shift - MLX5_ADAPTER_PAGE_SHIFT;
+        in->ctx.cqe_sz_flags = cqe_sz_to_mlx_sz(cqe_size) << 5;
+        in->ctx.page_offset = 0;
+        in->ctx.log_sz_usr_page = cpu_to_be32(ilog2(entries) << 24);
+        in->hdr.opmod = cpu_to_be16(MLX5_CQ_OPMOD_RESIZE);
+        in->cqn = cpu_to_be32(cq->mcq.cqn);
+
+        err = mlx5_core_modify_cq(&dev->mdev, &cq->mcq, in, inlen);
+        if (err)
+                goto ex_alloc;
+
+        if (udata) {
+                cq->ibcq.cqe = entries - 1;
+                ib_umem_release(cq->buf.umem);
+                cq->buf.umem = cq->resize_umem;
+                cq->resize_umem = NULL;
+        } else {
+                struct mlx5_ib_cq_buf tbuf;
+                int resized = 0;
+
+                spin_lock_irqsave(&cq->lock, flags);
+                if (cq->resize_buf) {
+                        err = copy_resize_cqes(cq);
+                        if (!err) {
+                                tbuf = cq->buf;
+                                cq->buf = *cq->resize_buf;
+                                kfree(cq->resize_buf);
+                                cq->resize_buf = NULL;
+                                resized = 1;
+                        }
+                }
+                cq->ibcq.cqe = entries - 1;
+                spin_unlock_irqrestore(&cq->lock, flags);
+                if (resized)
+                        free_cq_buf(dev, &tbuf);
+        }
+        mutex_unlock(&cq->resize_mutex);
+
+        mlx5_vfree(in);
+        return 0;
+
+ex_alloc:
+        mlx5_vfree(in);
+
+ex_resize:
+        if (udata)
+                un_resize_user(cq);
+        else
+                un_resize_kernel(dev, cq);
+ex:
+        mutex_unlock(&cq->resize_mutex);
+        return err;
 }
 
 int mlx5_ib_get_cqe_size(struct mlx5_ib_dev *dev, struct ib_cq *ibcq)
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index 5acef30a4998..389e31965773 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -195,6 +195,7 @@ struct mlx5_ib_cq_buf {
         struct mlx5_buf         buf;
         struct ib_umem          *umem;
         int                     cqe_size;
+        int                     nent;
 };
 
 enum mlx5_ib_qp_flags {
@@ -220,7 +221,7 @@ struct mlx5_ib_cq {
         /* protect resize cq
          */
         struct mutex            resize_mutex;
-        struct mlx5_ib_cq_resize *resize_buf;
+        struct mlx5_ib_cq_buf  *resize_buf;
         struct ib_umem         *resize_umem;
         int                     cqe_size;
 };
diff --git a/drivers/infiniband/hw/mlx5/user.h b/drivers/infiniband/hw/mlx5/user.h
index a886de3e593c..32a2a5dfc523 100644
--- a/drivers/infiniband/hw/mlx5/user.h
+++ b/drivers/infiniband/hw/mlx5/user.h
@@ -93,6 +93,9 @@ struct mlx5_ib_create_cq_resp {
 
 struct mlx5_ib_resize_cq {
         __u64   buf_addr;
+        __u16   cqe_size;
+        __u16   reserved0;
+        __u32   reserved1;
 };
 
 struct mlx5_ib_create_srq {
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cq.c b/drivers/net/ethernet/mellanox/mlx5/core/cq.c
index e6fedcf94182..43c5f4809526 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/cq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/cq.c
@@ -201,14 +201,14 @@ EXPORT_SYMBOL(mlx5_core_query_cq);
 
 
 int mlx5_core_modify_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
-                        struct mlx5_modify_cq_mbox_in *in)
+                        struct mlx5_modify_cq_mbox_in *in, int in_sz)
 {
         struct mlx5_modify_cq_mbox_out out;
         int err;
 
         memset(&out, 0, sizeof(out));
         in->hdr.opcode = cpu_to_be16(MLX5_CMD_OP_MODIFY_CQ);
-        err = mlx5_cmd_exec(dev, in, sizeof(*in), &out, sizeof(out));
+        err = mlx5_cmd_exec(dev, in, in_sz, &out, sizeof(out));
         if (err)
                 return err;
 
diff --git a/include/linux/mlx5/cq.h b/include/linux/mlx5/cq.h
index c3cf5a46abce..2202c7f72b75 100644
--- a/include/linux/mlx5/cq.h
+++ b/include/linux/mlx5/cq.h
@@ -79,9 +79,10 @@ enum {
         MLX5_CQE_RESP_SEND      = 2,
         MLX5_CQE_RESP_SEND_IMM  = 3,
         MLX5_CQE_RESP_SEND_INV  = 4,
-        MLX5_CQE_RESIZE_CQ      = 0xff, /* TBD */
+        MLX5_CQE_RESIZE_CQ      = 5,
         MLX5_CQE_REQ_ERR        = 13,
         MLX5_CQE_RESP_ERR       = 14,
+        MLX5_CQE_INVALID        = 15,
 };
 
 enum {
@@ -90,6 +91,13 @@ enum {
         MLX5_CQ_MODIFY_OVERRUN  = 1 << 2,
 };
 
+enum {
+        MLX5_CQ_OPMOD_RESIZE            = 1,
+        MLX5_MODIFY_CQ_MASK_LOG_SIZE    = 1 << 0,
+        MLX5_MODIFY_CQ_MASK_PG_OFFSET   = 1 << 1,
+        MLX5_MODIFY_CQ_MASK_PG_SIZE     = 1 << 2,
+};
+
 struct mlx5_cq_modify_params {
         int     type;
         union {
@@ -158,7 +166,7 @@ int mlx5_core_destroy_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq);
 int mlx5_core_query_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
                        struct mlx5_query_cq_mbox_out *out);
 int mlx5_core_modify_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
-                        struct mlx5_modify_cq_mbox_in *in);
+                        struct mlx5_modify_cq_mbox_in *in, int in_sz);
 int mlx5_debug_cq_add(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq);
 void mlx5_debug_cq_remove(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq);
 
diff --git a/include/linux/mlx5/device.h b/include/linux/mlx5/device.h
index dbb03caa8aed..87e23717df70 100644
--- a/include/linux/mlx5/device.h
+++ b/include/linux/mlx5/device.h
@@ -178,6 +178,7 @@ enum {
         MLX5_DEV_CAP_FLAG_ATOMIC        = 1LL << 18,
         MLX5_DEV_CAP_FLAG_ON_DMND_PG    = 1LL << 24,
         MLX5_DEV_CAP_FLAG_CQ_MODER      = 1LL << 29,
+        MLX5_DEV_CAP_FLAG_RESIZE_CQ     = 1LL << 30,
         MLX5_DEV_CAP_FLAG_RESIZE_SRQ    = 1LL << 32,
         MLX5_DEV_CAP_FLAG_REMOTE_FENCE  = 1LL << 38,
         MLX5_DEV_CAP_FLAG_TLP_HINTS     = 1LL << 39,
@@ -710,6 +711,7 @@ struct mlx5_modify_cq_mbox_in {
 
 struct mlx5_modify_cq_mbox_out {
         struct mlx5_outbox_hdr  hdr;
+        u8                      rsvd[8];
 };
 
 struct mlx5_enable_hca_mbox_in {