RDMA/rxe: Fix rxe_modify_srq

This patch corrects an error in rxe_modify_srq where if the
caller changes the srq size the actual new value is not returned
to the caller since it may be larger than what is requested.
Additionally it open codes the subroutine rcv_wqe_size() which
adds very little value, and makes some whitespace changes.

Fixes: 8700e3e7c485 ("Soft RoCE driver")
Link: https://lore.kernel.org/r/20230620140142.9452-1-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rxe: Change rxe_dbg to rxe_dbg_dev

Replace the name rxe_dbg with rxe_dbg_dev which better matches
the remaining rxe_dbg_xxx macros for debug messages with a
rxe device parameter. Reuse the name rxe_dbg for debug messages
which do not have a rxe device parameter.

Link: https://lore.kernel.org/r/20230303221623.8053-3-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rxe: Replace pr_xxx by rxe_dbg_xxx in rxe_srq.c

Replace calls to pr_xxx() in rxe_srq.c with rxe_dbg_xxx().

Link: https://lore.kernel.org/r/20221103171013.20659-11-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rxe: Add rxe_srq_cleanup()

Move cleanup code from rxe_destroy_srq() to rxe_srq_cleanup() which is
called after all references are dropped to allow code depending on the srq
object to complete.

Link: https://lore.kernel.org/r/20220421014042.26985-3-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rxe: Remove IB_SRQ_INIT_MASK

Currently the #define IB_SRQ_INIT_MASK is used to distinguish the
rxe_create_srq verb from the rxe_modify_srq verb so that some code can be
shared between these two subroutines.

This commit splits rxe_srq_chk_attr into two subroutines: rxe_srq_chk_init
and rxe_srq_chk_attr which handle the create_srq and modify_srq verbs
separately.

Link: https://lore.kernel.org/r/20220421014042.26985-2-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rxe: Cleanup rxe_pool_entry

Currently three different names are used to describe rxe pool elements.
They are referred to as entries, elems or pelems. This patch chooses one
'elem' and changes the other ones.

Link: https://lore.kernel.org/r/20211103050241.61293-3-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rxe: Remove the is_user members of struct rxe_sq/rxe_rq/rxe_srq

The is_user members of struct rxe_sq/rxe_rq/rxe_srq are unsed since
commit ae6e843fe08d ("RDMA/rxe: Add memory barriers to kernel queues").
In this case, it is fine to remove them directly.

Link: https://lore.kernel.org/r/20210930094813.226888-2-yangx.jy@fujitsu.com
Signed-off-by: Xiao Yang <yangx.jy@fujitsu.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rxe: Add memory barriers to kernel queues

Earlier patches added memory barriers to protect user space to kernel
space communications. The user space queues were previously shown to have
occasional memory synchonization errors which were removed by adding
smp_load_acquire, smp_store_release barriers. This patch extends that to
the case where queues are used between kernel space threads.

This patch also extends the queue types to include kernel ULP queues which
access the other end of the queues in kernel verbs calls like poll_cq and
post_send/recv.

Link: https://lore.kernel.org/r/20210914164206.19768-2-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rxe: Protext kernel index from user space

In order to prevent user space from modifying the index that belongs to
the kernel for shared queues let the kernel use a local copy of the index
and copy any new values of that index to the shared rxe_queue_bus struct.

This adds more switch statements which decreases the performance of the
queue API. Move the type into the parameter list for these functions so
that the compiler can optimize out the switch statements when the explicit
type is known. Modify all the calls in the driver on performance paths to
pass in the explicit queue type.

Link: https://lore.kernel.org/r/20210527194748.662636-4-rpearsonhpe@gmail.com
Link: https://lore.kernel.org/linux-rdma/20210526165239.GP1002214@@nvidia.com/
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rxe: Add a type flag to rxe_queue structs

To create optimal code only want to use smp_load_acquire() and
smp_store_release() for user indices in rxe_queue APIs since kernel
indices are protected by locks which also act as memory barriers. By
adding a type to the queues we can determine which indices need to be
protected.

Link: https://lore.kernel.org/r/20210527194748.662636-2-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rxe: Add SPDX hdrs to rxe source files

Add SPDX headers to all rxe .c and .h files.

Link: https://lore.kernel.org/r/20200827145439.2273-1-rpearson@hpe.com
Signed-off-by: Bob Pearson <rpearson@hpe.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

IB: Pass only ib_udata in function prototypes

Now when ib_udata is passed to all the driver's object create/destroy APIs
the ib_udata will carry the ib_ucontext for every user command. There is
no need to also pass the ib_ucontext via the functions prototypes.

Make ib_udata the only argument psssed.

Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/rxe: avoid srq memory leak

In rxe_queue_init, q and q->buf are allocated. In do_mmap_info, q->ip is
allocated. When error occurs, rxe_srq_from_init and the later error
handler do not free these allocated memories. This will make memory leak.

Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/rxe: Use structs to describe the uABI instead of opencoding

Open coding pointer math is not acceptable for describing the uABI in
RDMA. Provide structs for all the cases.

The udata is casted to the struct as close to the verbs entry point
as possible for maximum clarity. Function signatures and so forth
are revised to allow for this.

Tested-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/rxe: Remove unneeded cast in rxe_srq_from_attr()

It makes me nervous when we cast pointer parameters. I would estimate
that around 50% of the time, it indicates a bug. Here the cast is not
needed becaue u32 and and unsigned int are the same thing. Removing the
cast makes the code more robust and future proof in case any of the
types change.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Acked-by: Moni Shoua <monis@mellanox.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

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>