IB: Add userspace support for resizing CQs

Add support to uverbs to handle resizing userspace CQs (completion
queues), including adding an ABI for marshalling requests and
responses.  The kernel midlayer already has ib_resize_cq().

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

1 files changed, 41 insertions, 1 deletions

diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 407b6284d7d5..be1cef1b3116 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2005 Topspin Communications.  All rights reserved.
- * Copyright (c) 2005 Cisco Systems.  All rights reserved.
+ * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
  * Copyright (c) 2005 PathScale, Inc.  All rights reserved.
  *
  * This software is available to you under a choice of one of two
@@ -675,6 +675,46 @@ err:
 	return ret;
 }
 
+ssize_t ib_uverbs_resize_cq(struct ib_uverbs_file *file,
+			    const char __user *buf, int in_len,
+			    int out_len)
+{
+	struct ib_uverbs_resize_cq	cmd;
+	struct ib_uverbs_resize_cq_resp	resp;
+	struct ib_udata                 udata;
+	struct ib_cq			*cq;
+	int				ret = -EINVAL;
+
+	if (copy_from_user(&cmd, buf, sizeof cmd))
+		return -EFAULT;
+
+	INIT_UDATA(&udata, buf + sizeof cmd,
+		   (unsigned long) cmd.response + sizeof resp,
+		   in_len - sizeof cmd, out_len - sizeof resp);
+
+	mutex_lock(&ib_uverbs_idr_mutex);
+
+	cq = idr_find(&ib_uverbs_cq_idr, cmd.cq_handle);
+	if (!cq || cq->uobject->context != file->ucontext || !cq->device->resize_cq)
+		goto out;
+
+	ret = cq->device->resize_cq(cq, cmd.cqe, &udata);
+	if (ret)
+		goto out;
+
+	memset(&resp, 0, sizeof resp);
+	resp.cqe = cq->cqe;
+
+	if (copy_to_user((void __user *) (unsigned long) cmd.response,
+			 &resp, sizeof resp))
+		ret = -EFAULT;
+
+out:
+	mutex_unlock(&ib_uverbs_idr_mutex);
+
+	return ret ? ret : in_len;
+}
+
 ssize_t ib_uverbs_poll_cq(struct ib_uverbs_file *file,
 			  const char __user *buf, int in_len,
 			  int out_len)