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>

drivers/infiniband/core/uverbs.h

 /*
  * 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 Mellanox Technologies. All rights reserved.
  * Copyright (c) 2005 Voltaire, Inc. All rights reserved.
  * Copyright (c) 2005 PathScale, Inc. All rights reserved.
@@ -178,6 +178,7 @@ IB_UVERBS_DECLARE_CMD(reg_mr);
 IB_UVERBS_DECLARE_CMD(dereg_mr);
 IB_UVERBS_DECLARE_CMD(create_comp_channel);
 IB_UVERBS_DECLARE_CMD(create_cq);
+IB_UVERBS_DECLARE_CMD(resize_cq);
 IB_UVERBS_DECLARE_CMD(poll_cq);
 IB_UVERBS_DECLARE_CMD(req_notify_cq);
 IB_UVERBS_DECLARE_CMD(destroy_cq);

drivers/infiniband/core/uverbs_cmd.c

 /*
  * 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 @@ ssize_t ib_uverbs_create_cq(struct ib_uverbs_file *file,
 	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)

drivers/infiniband/core/uverbs_main.c

 /*
  * 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 Mellanox Technologies. All rights reserved.
  * Copyright (c) 2005 Voltaire, Inc. All rights reserved.
  * Copyright (c) 2005 PathScale, Inc. All rights reserved.
@@ -91,6 +91,7 @@ static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
 	[IB_USER_VERBS_CMD_DEREG_MR]      	= ib_uverbs_dereg_mr,
 	[IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL] = ib_uverbs_create_comp_channel,
 	[IB_USER_VERBS_CMD_CREATE_CQ]     	= ib_uverbs_create_cq,
+	[IB_USER_VERBS_CMD_RESIZE_CQ]     	= ib_uverbs_resize_cq,
 	[IB_USER_VERBS_CMD_POLL_CQ]     	= ib_uverbs_poll_cq,
 	[IB_USER_VERBS_CMD_REQ_NOTIFY_CQ]     	= ib_uverbs_req_notify_cq,
 	[IB_USER_VERBS_CMD_DESTROY_CQ]    	= ib_uverbs_destroy_cq,

drivers/infiniband/core/verbs.c

@@ -5,7 +5,7 @@
  * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
  * Copyright (c) 2004 Voltaire Corporation.  All rights reserved.
  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
- * Copyright (c) 2005 Cisco Systems.  All rights reserved.
+ * Copyright (c) 2005, 2006 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
@@ -326,7 +326,7 @@ int ib_resize_cq(struct ib_cq *cq,
                  int           cqe)
 {
 	return cq->device->resize_cq ?
-		cq->device->resize_cq(cq, cqe) : -ENOSYS;
+		cq->device->resize_cq(cq, cqe, NULL) : -ENOSYS;
 }
 EXPORT_SYMBOL(ib_resize_cq);
 

include/rdma/ib_user_verbs.h

 /*
  * 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
@@ -265,6 +265,17 @@ struct ib_uverbs_create_cq_resp {
 	__u32 cqe;
 };
 
+struct ib_uverbs_resize_cq {
+	__u64 response;
+	__u32 cq_handle;
+	__u32 cqe;
+	__u64 driver_data[0];
+};
+
+struct ib_uverbs_resize_cq_resp {
+	__u32 cqe;
+};
+
 struct ib_uverbs_poll_cq {
 	__u64 response;
 	__u32 cq_handle;

include/rdma/ib_verbs.h

@@ -5,7 +5,7 @@
  * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
  * Copyright (c) 2004 Voltaire Corporation.  All rights reserved.
  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
- * Copyright (c) 2005 Cisco Systems.  All rights reserved.
+ * Copyright (c) 2005, 2006 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
@@ -880,7 +880,8 @@ struct ib_device {
 						struct ib_ucontext *context,
 						struct ib_udata *udata);
 	int                        (*destroy_cq)(struct ib_cq *cq);
-	int                        (*resize_cq)(struct ib_cq *cq, int cqe);
+	int                        (*resize_cq)(struct ib_cq *cq, int cqe,
+						struct ib_udata *udata);
 	int                        (*poll_cq)(struct ib_cq *cq, int num_entries,
 					      struct ib_wc *wc);
 	int                        (*peek_cq)(struct ib_cq *cq, int wc_cnt);