Soft RoCE driver

Soft RoCE (RXE) - The software RoCE driver

ib_rxe implements the RDMA transport and registers to the RDMA core
device as a kernel verbs provider. It also implements the packet IO
layer. On the other hand ib_rxe registers to the Linux netdev stack
as a udp encapsulating protocol, in that case RDMA, for sending and
receiving packets over any Ethernet device.  This yields a RDMA
transport over the UDP/Ethernet network layer forming a RoCEv2
compatible device.

The configuration procedure of the Soft RoCE drivers requires
binding to any existing Ethernet network device. This is done with
/sys interface.

A userspace Soft RoCE library (librxe) provides user applications
the ability to run with Soft RoCE devices.  The use of rxe verbs ins
user space requires the inclusion of librxe as a device specifics
plug-in to libibverbs. librxe is packaged separately.

Architecture:

     +-----------------------------------------------------------+
     |                          Application                      |
     +-----------------------------------------------------------+
                            +-----------------------------------+
                            |             libibverbs            |
User                        +-----------------------------------+
                            +----------------+ +----------------+
                            | librxe         | | HW RoCE lib    |
                            +----------------+ +----------------+
+---------------------------------------------------------------+
     +--------------+                           +------------+
     | Sockets      |                           | RDMA ULP   |
     +--------------+                           +------------+
     +--------------+                  +---------------------+
     | TCP/IP       |                  | ib_core             |
     +--------------+                  +---------------------+
                             +------------+ +----------------+
Kernel                       | ib_rxe     | | HW RoCE driver |
                             +------------+ +----------------+
     +------------------------------------+
     | NIC driver                         |
     +------------------------------------+

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     +-----------------------------------------------------------+
     |                          Application                      |
     +-----------------------------------------------------------+
                            +-----------------------------------+
                            |             libibverbs            |
User                        +-----------------------------------+
                            +----------------+ +----------------+
                            | librxe         | | HW RoCE lib    |
                            +----------------+ +----------------+
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     +--------------+                           +------------+
     | Sockets      |                           | RDMA ULP   |
     +--------------+                           +------------+
     +--------------+                  +---------------------+
     | TCP/IP       |                  | ib_core             |
     +--------------+                  +---------------------+
                             +------------+ +----------------+
Kernel                       | ib_rxe     | | HW RoCE driver |
                             +------------+ +----------------+
     +------------------------------------+
     | NIC driver                         |
     +------------------------------------+
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Soft RoCE resources:

[1[ https://github.com/SoftRoCE/librxe-dev librxe - source code in
Github
[2] https://github.com/SoftRoCE/rxe-dev/wiki/rxe-dev:-Home - Soft RoCE
Wiki page
[3] https://github.com/SoftRoCE/librxe-dev - Soft RoCE userspace library

Signed-off-by: Kamal Heib <kamalh@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Reviewed-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 163 insertions, 0 deletions

diff --git a/drivers/infiniband/sw/rxe/rxe_pool.h b/drivers/infiniband/sw/rxe/rxe_pool.h
new file mode 100644
index 000000000000..4d04830adcae
--- /dev/null
+++ b/drivers/infiniband/sw/rxe/rxe_pool.h
@@ -0,0 +1,163 @@
+/*
+ * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
+ * Copyright (c) 2015 System Fabric Works, 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 RXE_POOL_H
+#define RXE_POOL_H
+
+#define RXE_POOL_ALIGN		(16)
+#define RXE_POOL_CACHE_FLAGS	(0)
+
+enum rxe_pool_flags {
+	RXE_POOL_ATOMIC		= BIT(0),
+	RXE_POOL_INDEX		= BIT(1),
+	RXE_POOL_KEY		= BIT(2),
+};
+
+enum rxe_elem_type {
+	RXE_TYPE_UC,
+	RXE_TYPE_PD,
+	RXE_TYPE_AH,
+	RXE_TYPE_SRQ,
+	RXE_TYPE_QP,
+	RXE_TYPE_CQ,
+	RXE_TYPE_MR,
+	RXE_TYPE_MW,
+	RXE_TYPE_MC_GRP,
+	RXE_TYPE_MC_ELEM,
+	RXE_NUM_TYPES,		/* keep me last */
+};
+
+struct rxe_type_info {
+	char			*name;
+	size_t			size;
+	void			(*cleanup)(void *obj);
+	enum rxe_pool_flags	flags;
+	u32			max_index;
+	u32			min_index;
+	size_t			key_offset;
+	size_t			key_size;
+	struct kmem_cache	*cache;
+};
+
+extern struct rxe_type_info rxe_type_info[];
+
+enum rxe_pool_state {
+	rxe_pool_invalid,
+	rxe_pool_valid,
+};
+
+struct rxe_pool_entry {
+	struct rxe_pool		*pool;
+	struct kref		ref_cnt;
+	struct list_head	list;
+
+	/* only used if indexed or keyed */
+	struct rb_node		node;
+	u32			index;
+};
+
+struct rxe_pool {
+	struct rxe_dev		*rxe;
+	spinlock_t              pool_lock; /* pool spinlock */
+	size_t			elem_size;
+	struct kref		ref_cnt;
+	void			(*cleanup)(void *obj);
+	enum rxe_pool_state	state;
+	enum rxe_pool_flags	flags;
+	enum rxe_elem_type	type;
+
+	unsigned int		max_elem;
+	atomic_t		num_elem;
+
+	/* only used if indexed or keyed */
+	struct rb_root		tree;
+	unsigned long		*table;
+	size_t			table_size;
+	u32			max_index;
+	u32			min_index;
+	u32			last;
+	size_t			key_offset;
+	size_t			key_size;
+};
+
+/* initialize slab caches for managed objects */
+int rxe_cache_init(void);
+
+/* cleanup slab caches for managed objects */
+void rxe_cache_exit(void);
+
+/* initialize a pool of objects with given limit on
+ * number of elements. gets parameters from rxe_type_info
+ * pool elements will be allocated out of a slab cache
+ */
+int rxe_pool_init(struct rxe_dev *rxe, struct rxe_pool *pool,
+		  enum rxe_elem_type type, u32 max_elem);
+
+/* free resources from object pool */
+int rxe_pool_cleanup(struct rxe_pool *pool);
+
+/* allocate an object from pool */
+void *rxe_alloc(struct rxe_pool *pool);
+
+/* assign an index to an indexed object and insert object into
+ *  pool's rb tree
+ */
+void rxe_add_index(void *elem);
+
+/* drop an index and remove object from rb tree */
+void rxe_drop_index(void *elem);
+
+/* assign a key to a keyed object and insert object into
+ *  pool's rb tree
+ */
+void rxe_add_key(void *elem, void *key);
+
+/* remove elem from rb tree */
+void rxe_drop_key(void *elem);
+
+/* lookup an indexed object from index. takes a reference on object */
+void *rxe_pool_get_index(struct rxe_pool *pool, u32 index);
+
+/* lookup keyed object from key. takes a reference on the object */
+void *rxe_pool_get_key(struct rxe_pool *pool, void *key);
+
+/* cleanup an object when all references are dropped */
+void rxe_elem_release(struct kref *kref);
+
+/* take a reference on an object */
+#define rxe_add_ref(elem) kref_get(&(elem)->pelem.ref_cnt)
+
+/* drop a reference on an object */
+#define rxe_drop_ref(elem) kref_put(&(elem)->pelem.ref_cnt, rxe_elem_release)
+
+#endif /* RXE_POOL_H */