IB/srpt: Introduce helper functions for SRQ allocation and freeing

The only functional change in this patch is in the srpt_add_one()
error path: if allocating the ring buffer for the SRQ fails, fall
back to non-SRQ mode instead of disabling SRP target functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 98b1b80e476bbfb75c03c0fa8d63ee44243fbd5b..a5f232e9b1f37cc68a62d68673ef610c2a5cb3da 100644 (file)
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -2510,6 +2510,74 @@ static struct se_wwn *srpt_lookup_wwn(const char *name)
        return wwn;
 }
 
+static void srpt_free_srq(struct srpt_device *sdev)
+{
+       if (!sdev->srq)
+               return;
+
+       ib_destroy_srq(sdev->srq);
+       srpt_free_ioctx_ring((struct srpt_ioctx **)sdev->ioctx_ring, sdev,
+                            sdev->srq_size, srp_max_req_size, DMA_FROM_DEVICE);
+       sdev->srq = NULL;
+}
+
+static int srpt_alloc_srq(struct srpt_device *sdev)
+{
+       struct ib_srq_init_attr srq_attr = {
+               .event_handler = srpt_srq_event,
+               .srq_context = (void *)sdev,
+               .attr.max_wr = sdev->srq_size,
+               .attr.max_sge = 1,
+               .srq_type = IB_SRQT_BASIC,
+       };
+       struct ib_device *device = sdev->device;
+       struct ib_srq *srq;
+       int i;
+
+       WARN_ON_ONCE(sdev->srq);
+       srq = ib_create_srq(sdev->pd, &srq_attr);
+       if (IS_ERR(srq)) {
+               pr_debug("ib_create_srq() failed: %ld\n", PTR_ERR(srq));
+               return PTR_ERR(srq);
+       }
+
+       pr_debug("create SRQ #wr= %d max_allow=%d dev= %s\n", sdev->srq_size,
+                sdev->device->attrs.max_srq_wr, device->name);
+
+       sdev->ioctx_ring = (struct srpt_recv_ioctx **)
+               srpt_alloc_ioctx_ring(sdev, sdev->srq_size,
+                                     sizeof(*sdev->ioctx_ring[0]),
+                                     srp_max_req_size, DMA_FROM_DEVICE);
+       if (!sdev->ioctx_ring) {
+               ib_destroy_srq(srq);
+               return -ENOMEM;
+       }
+
+       sdev->use_srq = true;
+       sdev->srq = srq;
+
+       for (i = 0; i < sdev->srq_size; ++i)
+               srpt_post_recv(sdev, NULL, sdev->ioctx_ring[i]);
+
+       return 0;
+}
+
+static int srpt_use_srq(struct srpt_device *sdev, bool use_srq)
+{
+       struct ib_device *device = sdev->device;
+       int ret = 0;
+
+       if (!use_srq) {
+               srpt_free_srq(sdev);
+               sdev->use_srq = false;
+       } else if (use_srq && !sdev->srq) {
+               ret = srpt_alloc_srq(sdev);
+       }
+       pr_debug("%s(%s): use_srq = %d; ret = %d\n", __func__, device->name,
+                sdev->use_srq, ret);
+       return ret;
+}
+
 /**
  * srpt_add_one() - Infiniband device addition callback function.
  */
@@ -2517,7 +2585,6 @@ static void srpt_add_one(struct ib_device *device)
 {
        struct srpt_device *sdev;
        struct srpt_port *sport;
-       struct ib_srq_init_attr srq_attr;
        int i;
 
        pr_debug("device = %p\n", device);
@@ -2539,38 +2606,7 @@ static void srpt_add_one(struct ib_device *device)
 
        sdev->srq_size = min(srpt_srq_size, sdev->device->attrs.max_srq_wr);
 
-       srq_attr.event_handler = srpt_srq_event;
-       srq_attr.srq_context = (void *)sdev;
-       srq_attr.attr.max_wr = sdev->srq_size;
-       srq_attr.attr.max_sge = 1;
-       srq_attr.attr.srq_limit = 0;
-       srq_attr.srq_type = IB_SRQT_BASIC;
-
-       sdev->srq = sdev->port[0].port_attrib.use_srq ?
-               ib_create_srq(sdev->pd, &srq_attr) : ERR_PTR(-ENOTSUPP);
-       if (IS_ERR(sdev->srq)) {
-               pr_debug("ib_create_srq() failed: %ld\n", PTR_ERR(sdev->srq));
-
-               /* SRQ not supported. */
-               sdev->use_srq = false;
-       } else {
-               pr_debug("create SRQ #wr= %d max_allow=%d dev= %s\n",
-                        sdev->srq_size, sdev->device->attrs.max_srq_wr,
-                        device->name);
-
-               sdev->use_srq = true;
-
-               sdev->ioctx_ring = (struct srpt_recv_ioctx **)
-                       srpt_alloc_ioctx_ring(sdev, sdev->srq_size,
-                                             sizeof(*sdev->ioctx_ring[0]),
-                                             srp_max_req_size,
-                                             DMA_FROM_DEVICE);
-               if (!sdev->ioctx_ring)
-                       goto err_pd;
-
-               for (i = 0; i < sdev->srq_size; ++i)
-                       srpt_post_recv(sdev, NULL, sdev->ioctx_ring[i]);
-       }
+       srpt_use_srq(sdev, sdev->port[0].port_attrib.use_srq);
 
        if (!srpt_service_guid)
                srpt_service_guid = be64_to_cpu(device->node_guid);
@@ -2630,12 +2666,7 @@ err_event:
 err_cm:
        ib_destroy_cm_id(sdev->cm_id);
 err_ring:
-       if (sdev->use_srq)
-               ib_destroy_srq(sdev->srq);
-       srpt_free_ioctx_ring((struct srpt_ioctx **)sdev->ioctx_ring, sdev,
-                            sdev->srq_size, srp_max_req_size,
-                            DMA_FROM_DEVICE);
-err_pd:
+       srpt_free_srq(sdev);
        ib_dealloc_pd(sdev->pd);
 free_dev:
        kfree(sdev);
@@ -2678,10 +2709,8 @@ static void srpt_remove_one(struct ib_device *device, void *client_data)
        spin_unlock(&srpt_dev_lock);
        srpt_release_sdev(sdev);
 
-       if (sdev->use_srq)
-               ib_destroy_srq(sdev->srq);
-       srpt_free_ioctx_ring((struct srpt_ioctx **)sdev->ioctx_ring, sdev,
-                            sdev->srq_size, srp_max_req_size, DMA_FROM_DEVICE);
+       srpt_free_srq(sdev);
+
        ib_dealloc_pd(sdev->pd);
 
        kfree(sdev);