[RFC ABI V2 5/8] RDMA/core: Add new ioctl interface

@@ -29,4 +29,4 @@ ib_umad-y :=			user_mad.o
 ib_ucm-y :=			ucm.o
 
 ib_uverbs-y :=			uverbs_main.o uverbs_cmd.o uverbs_marshall.o \
-				rdma_core.o
+				rdma_core.o uverbs_ioctl.o uverbs_ioctl_cmd.o

@@ -245,6 +245,9 @@ struct ib_device *ib_alloc_device(size_t size)
 	INIT_LIST_HEAD(&device->port_list);
 	INIT_LIST_HEAD(&device->type_list);
 
+	/* TODO: don't forget to initialize device->driver_id, so verbs handshake between
+	 * user space<->kernel space will work for other values than driver_id == 0.
+	 */
 	return device;
 }
 EXPORT_SYMBOL(ib_alloc_device);

@@ -41,6 +41,7 @@
 #include <linux/mutex.h>
 #include <linux/completion.h>
 #include <linux/cdev.h>
+#include <linux/rwsem.h>
 
 #include <rdma/ib_verbs.h>
 #include <rdma/ib_umem.h>

@@ -83,6 +84,8 @@
  * released when the CQ is destroyed.
  */
 
+long ib_uverbs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
+
 struct ib_uverbs_device {
 	atomic_t				refcount;
 	int					num_comp_vectors;

@@ -121,6 +124,7 @@ struct ib_uverbs_file {
 	struct ib_uverbs_event_file	       *async_file;
 	struct list_head			list;
 	int					is_closed;
+	struct rw_semaphore			close_sem;
 };
 
 struct ib_uverbs_event {

@@ -361,6 +361,7 @@ ssize_t ib_uverbs_get_context(struct ib_uverbs_file *file,
 	}
 
 	file->ucontext = ucontext;
+	ucontext->ufile = file;
 
 	fd_install(resp.async_fd, filp);
 

@@ -0,0 +1,279 @@
+/*
+ * Copyright (c) 2016, Mellanox Technologies inc.  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
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <rdma/rdma_ioctl.h>
+#include <rdma/uverbs_ioctl.h>
+#include "rdma_core.h"
+#include "uverbs.h"
+
+static int uverbs_validate_attr(struct ib_device *ibdev,
+				struct ib_ucontext *ucontext,
+				const struct ib_uverbs_attr *uattr,
+				u16 attr_id,
+				const struct uverbs_attr_chain_spec *chain_spec,
+				struct uverbs_attr *elements)
+{
+	const struct uverbs_attr_spec *spec;
+	struct uverbs_attr *e;
+
+	if (uattr->reserved)
+		return -EINVAL;
+
+	if (attr_id >= chain_spec->num_attrs)
+		return -EINVAL;
+
+	spec = &chain_spec->attrs[attr_id];
+	e = &elements[attr_id];
+
+	if (e->valid)
+		return -EINVAL;
+
+	switch (spec->type) {
+	case UVERBS_ATTR_TYPE_PTR_IN:
+	case UVERBS_ATTR_TYPE_PTR_OUT:
+		/* If spec->len is zero, don't validate (flexible) */
+		if (spec->len && uattr->len != spec->len)
+			return -EINVAL;
+		e->cmd_attr.ptr = (void * __user)uattr->ptr_idr;
+		e->cmd_attr.len = uattr->len;
+		break;
+
+	case UVERBS_ATTR_TYPE_IDR:
+		if (uattr->len != 0 || (uattr->ptr_idr >> 32) || (!ucontext))
+			return -EINVAL;
+
+		e->obj_attr.idr = (uint32_t)uattr->ptr_idr;
+		e->obj_attr.val = spec;
+		e->obj_attr.type = uverbs_get_type(ibdev,
+						   spec->idr.idr_type);
+		if (!e->obj_attr.type)
+			return -EINVAL;
+
+		e->obj_attr.uobject = uverbs_get_type_from_idr(e->obj_attr.type,
+							       ucontext,
+							       spec->idr.access,
+							       e->obj_attr.idr);
+		if (!e->obj_attr.uobject)
+			return -EINVAL;
+
+		break;
+	};
+
+	e->valid = 1;
+	return 0;
+}
+
+static int uverbs_validate(struct ib_device *ibdev,
+			   struct ib_ucontext *ucontext,
+			   const struct ib_uverbs_attr *uattrs,
+			   size_t num_attrs,
+			   const struct action_spec *action_spec,
+			   struct uverbs_attr_array *attr_array)
+{
+	size_t i;
+	int ret;
+	int n_val = -1;
+
+	for (i = 0; i < num_attrs; i++) {
+		const struct ib_uverbs_attr *uattr = &uattrs[i];
+		__u16 attr_id = uattr->attr_id;
+		const struct uverbs_attr_chain_spec *chain_spec;
+
+		ret = action_spec->dist(&attr_id, action_spec->priv);
+		if (ret < 0)
+			return ret;
+
+		if (ret > n_val)
+			n_val = ret;
+
+		chain_spec = action_spec->validator_chains[ret];
+		ret = uverbs_validate_attr(ibdev, ucontext, uattr, attr_id,
+					   chain_spec, attr_array[ret].attrs);
+		if (ret)
+			return ret;
+
+	}
+
+	return n_val >= 0 ? n_val + 1 : n_val;
+}
+
+static int uverbs_handle_action(const struct ib_uverbs_attr *uattrs,
+				size_t num_attrs,
+				struct ib_device *ibdev,
+				struct ib_uverbs_file *ufile,
+				const struct uverbs_action *handler,
+				struct uverbs_attr_array *attr_array)
+{
+	int ret;
+	int n_val;
+
+	n_val = uverbs_validate(ibdev, ufile->ucontext, uattrs, num_attrs,
+				&handler->chain, attr_array);
+	if (n_val <= 0)
+		return n_val;
+
+	ret = handler->handler(ibdev, ufile, attr_array, n_val,
+			       handler->priv);
+	uverbs_unlock_objects(attr_array, n_val, &handler->chain, !ret);
+
+	return ret;
+}
+
+static long ib_uverbs_cmd_verbs(struct ib_device *ib_dev,
+				struct ib_uverbs_file *file,
+				struct ib_uverbs_ioctl_hdr *hdr,
+				void __user *buf)
+{
+	const struct uverbs_type_actions *type;
+	const struct uverbs_action *action;
+	const struct action_spec *action_spec;
+	long err = 0;
+	unsigned int num_specs = 0;
+	unsigned int i;
+	struct {
+		struct ib_uverbs_attr		*uattrs;
+		struct uverbs_attr_array	*uverbs_attr_array;
+	} *ctx = NULL;
+	struct uverbs_attr *curr_attr;
+	size_t ctx_size;
+
+	if (!ib_dev)
+		return -EIO;
+
+	if (ib_dev->types->num_types < hdr->object_type ||
+	    ib_dev->driver_id != hdr->driver_id)
+		return -EINVAL;
+
+	type = ib_dev->types->types[hdr->object_type];
+	if (!type || type->num_actions < hdr->action)
+		return -EOPNOTSUPP;
+
+	action = &type->actions[hdr->action];
+	if (!action)
+		return -EOPNOTSUPP;
+
+	action_spec = &action->chain;
+	for (i = 0; i < action_spec->num_chains;
+	     num_specs += action_spec->validator_chains[i]->num_attrs, i++)
+		;
+
+	ctx_size = sizeof(*ctx->uattrs) * hdr->num_attrs +
+		   sizeof(*ctx->uverbs_attr_array->attrs) * num_specs +
+		   sizeof(struct uverbs_attr_array) * action_spec->num_chains +
+		   sizeof(*ctx);
+
+	ctx = kzalloc(ctx_size, GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->uverbs_attr_array = (void *)ctx + sizeof(*ctx);
+	ctx->uattrs = (void *)(ctx->uverbs_attr_array +
+			       action_spec->num_chains);
+	curr_attr = (void *)(ctx->uattrs + hdr->num_attrs);
+	for (i = 0; i < action_spec->num_chains; i++) {
+		ctx->uverbs_attr_array[i].attrs = curr_attr;
+		ctx->uverbs_attr_array[i].num_attrs =
+			action_spec->validator_chains[i]->num_attrs;
+		curr_attr += action_spec->validator_chains[i]->num_attrs;
+	}
+
+	err = copy_from_user(ctx->uattrs, buf,
+			     sizeof(*ctx->uattrs) * hdr->num_attrs);
+	if (err) {
+		err = -EFAULT;
+		goto out;
+	}
+
+	err = uverbs_handle_action(ctx->uattrs, hdr->num_attrs, ib_dev,
+				   file, action, ctx->uverbs_attr_array);
+out:
+	kfree(ctx);
+	return err;
+}
+
+#define IB_UVERBS_MAX_CMD_SZ 4096
+
+long ib_uverbs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	struct ib_uverbs_file *file = filp->private_data;
+	struct ib_uverbs_ioctl_hdr __user *user_hdr =
+		(struct ib_uverbs_ioctl_hdr __user *)arg;
+	struct ib_uverbs_ioctl_hdr hdr;
+	struct ib_device *ib_dev;
+	int srcu_key;
+	long err;
+
+	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
+	ib_dev = srcu_dereference(file->device->ib_dev,
+				  &file->device->disassociate_srcu);
+	if (!ib_dev) {
+		err = -EIO;
+		goto out;
+	}
+
+	if (cmd == RDMA_DIRECT_IOCTL) {
+		/* TODO? */
+		err = -ENOSYS;
+		goto out;
+	} else {
+		if (cmd != RDMA_VERBS_IOCTL) {
+			err = -ENOIOCTLCMD;
+			goto out;
+		}
+
+		err = copy_from_user(&hdr, user_hdr, sizeof(hdr));
+
+		if (err || hdr.length > IB_UVERBS_MAX_CMD_SZ ||
+		    hdr.length <= sizeof(hdr) ||
+		    hdr.length != sizeof(hdr) + hdr.num_attrs * sizeof(struct ib_uverbs_attr)) {
+			err = -EINVAL;
+			goto out;
+		}
+
+		/* currently there are no flags supported */
+		if (hdr.flags) {
+			err = -EOPNOTSUPP;
+			goto out;
+		}
+
+		/* We're closing, fail all commands */
+		if (!down_read_trylock(&file->close_sem))
+			return -EIO;
+		err = ib_uverbs_cmd_verbs(ib_dev, file, &hdr,
+					  (__user void *)arg + sizeof(hdr));
+		up_read(&file->close_sem);
+	}
+out:
+	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
+
+	return err;
+}

@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2016, Mellanox Technologies inc.  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
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <rdma/uverbs_ioctl_cmd.h>
+#include <rdma/ib_verbs.h>
+#include <linux/bug.h>
+#include "uverbs.h"
+
+#define IB_UVERBS_VENDOR_FLAG	0x8000
+
+int ib_uverbs_std_dist(__u16 *attr_id, void *priv)
+{
+	if (*attr_id & IB_UVERBS_VENDOR_FLAG) {
+		*attr_id &= ~IB_UVERBS_VENDOR_FLAG;
+		return 1;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(ib_uverbs_std_dist);
+
+int uverbs_action_std_handle(struct ib_device *ib_dev,
+			     struct ib_uverbs_file *ufile,
+			     struct uverbs_attr_array *ctx, size_t num,
+			     void *_priv)
+{
+	struct uverbs_action_std_handler *priv = _priv;
+
+	if (!ufile->ucontext)
+		return -EINVAL;
+
+	WARN_ON((num != 1) && (num != 2));
+	return priv->handler(ib_dev, ufile->ucontext, &ctx[0],
+			     (num == 2 ? &ctx[1] : NULL),
+			     priv->priv);
+}
+EXPORT_SYMBOL(uverbs_action_std_handle);
+
+int uverbs_action_std_ctx_handle(struct ib_device *ib_dev,
+				 struct ib_uverbs_file *ufile,
+				 struct uverbs_attr_array *ctx, size_t num,
+				 void *_priv)
+{
+	struct uverbs_action_std_ctx_handler *priv = _priv;
+
+	WARN_ON((num != 1) && (num != 2));
+	return priv->handler(ib_dev, ufile, &ctx[0], (num == 2 ? &ctx[1] : NULL), priv->priv);
+}
+EXPORT_SYMBOL(uverbs_action_std_ctx_handle);
+

@@ -49,6 +49,7 @@
 #include <asm/uaccess.h>
 
 #include <rdma/ib.h>
+#include <rdma/rdma_ioctl.h>
 
 #include "uverbs.h"
 

@@ -211,6 +212,7 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
 {
 	struct ib_uobject *uobj, *tmp;
 
+	down_write(&file->close_sem);
 	context->closing = 1;
 
 	list_for_each_entry_safe(uobj, tmp, &context->ah_list, list) {

@@ -306,6 +308,7 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
 	}
 
 	put_pid(context->tgid);
+	up_write(&file->close_sem);
 
 	return context->device->dealloc_ucontext(context);
 }

@@ -915,6 +918,7 @@ static int ib_uverbs_open(struct inode *inode, struct file *filp)
 		goto err;
 	}
 
+	init_rwsem(&file->close_sem);
 	file->device	 = dev;
 	file->ucontext	 = NULL;
 	file->async_file = NULL;

@@ -973,6 +977,7 @@ static const struct file_operations uverbs_fops = {
 	.open	 = ib_uverbs_open,
 	.release = ib_uverbs_close,
 	.llseek	 = no_llseek,
+	.unlocked_ioctl = ib_uverbs_ioctl,
 };
 
 static const struct file_operations uverbs_mmap_fops = {

@@ -982,6 +987,7 @@ static const struct file_operations uverbs_mmap_fops = {
 	.open	 = ib_uverbs_open,
 	.release = ib_uverbs_close,
 	.llseek	 = no_llseek,
+	.unlocked_ioctl = ib_uverbs_ioctl,
 };
 
 static struct ib_client uverbs_client = {

@@ -1314,6 +1314,7 @@ struct ib_umem;
 
 struct ib_ucontext {
 	struct ib_device       *device;
+	struct ib_uverbs_file  *ufile;
 	struct list_head	pd_list;
 	struct list_head	mr_list;
 	struct list_head	mw_list;

@@ -1976,6 +1977,7 @@ struct ib_device {
 	int (*get_port_immutable)(struct ib_device *, u8, struct ib_port_immutable *);
 	struct list_head type_list;
 
+	u16				driver_id;
 	const struct uverbs_types	*types;
 };
 

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2016, Mellanox Technologies inc.  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
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef _UVERBS_IOCTL_CMD_
+#define _UVERBS_IOCTL_CMD_
+
+#include <rdma/uverbs_ioctl.h>
+
+int ib_uverbs_std_dist(__u16 *attr_id, void *priv);
+
+/* common validators */
+
+int uverbs_action_std_handle(struct ib_device *ib_dev,
+			     struct ib_uverbs_file *ufile,
+			     struct uverbs_attr_array *ctx, size_t num,
+			     void *_priv);
+int uverbs_action_std_ctx_handle(struct ib_device *ib_dev,
+				 struct ib_uverbs_file *ufile,
+				 struct uverbs_attr_array *ctx, size_t num,
+				 void *_priv);
+
+struct uverbs_action_std_handler {
+	int (*handler)(struct ib_device *ib_dev, struct ib_ucontext *ucontext,
+		       struct uverbs_attr_array *common,
+		       struct uverbs_attr_array *vendor,
+		       void *priv);
+	void *priv;
+};
+
+struct uverbs_action_std_ctx_handler {
+	int (*handler)(struct ib_device *ib_dev, struct ib_uverbs_file *ufile,
+		       struct uverbs_attr_array *common,
+		       struct uverbs_attr_array *vendor,
+		       void *priv);
+	void *priv;
+};
+
+#endif
+

@@ -42,6 +42,29 @@
  */
 #define IB_IOCTL_MAGIC			RDMA_IOCTL_MAGIC
 
+#define RDMA_VERBS_IOCTL \
+	_IOWR(RDMA_IOCTL_MAGIC, 1, struct ib_uverbs_ioctl_hdr)
+
+#define RDMA_DIRECT_IOCTL \
+	_IOWR(RDMA_IOCTL_MAGIC, 2, struct ib_uverbs_ioctl_hdr)
+
+struct ib_uverbs_attr {
+	__u16 attr_id;		/* command specific type attribute */
+	__u16 len;		/* NA for idr */
+	__u32 reserved;
+	 __u64 ptr_idr;		/* ptr typeo command/idr handle */
+};
+
+struct ib_uverbs_ioctl_hdr {
+	__u16 length;
+	__u16 flags;
+	__u16 object_type;
+	__u16 driver_id;
+	__u16 action;
+	__u16 num_attrs;
+	struct ib_uverbs_attr  attrs[0];
+};
+
 /* Legacy part
  * !!!! NOTE: It uses the same command index as VERBS
  */