net/smc: Fix dependency of SMC on ISM

When the SMC protocol is built into the kernel proper while ISM is
configured to be built as module, linking the kernel fails due to
unresolved dependencies out of net/smc/smc_ism.o to
ism_get_smcd_ops, ism_register_client, and ism_unregister_client
as reported via the linux-next test automation (see link).
This however is a bug introduced a while ago.

Correct the dependency list in ISM's and SMC's Kconfig to reflect the
dependencies that are actually inverted. With this you cannot build a
kernel with CONFIG_SMC=y and CONFIG_ISM=m. Either ISM needs to be 'y',
too - or a 'n'. That way, SMC can still be configured on non-s390
architectures that do not have (nor need) an ISM driver.

Fixes: 89e7d2ba61b7 ("net/ism: Add new API for client registration")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Closes: https://lore.kernel.org/linux-next/d53b5b50-d894-4df8-8969-fd39e63440ae@infradead.org/
Co-developed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Simon Horman <horms@kernel.org> # build-tested
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Link: https://lore.kernel.org/r/20231006125847.1517840-1-gbayer@linux.ibm.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net/smc: remove Kconfig warning

Now separate memory regions are created and registered for separate
RMBs. The unsafe_global_rkey of the protection domain is no longer
used. Thus the exposing memory warning can be removed.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc: Add warning about remote memory exposure

The driver explicitly bypasses APIs to register all memory once a
connection is made, and thus allows remote access to memory.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Acked-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

smc: netlink interface for SMC sockets

Support for SMC socket monitoring via netlink sockets of protocol
NETLINK_SOCK_DIAG.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

smc: establish new socket family

* enable smc module loading and unloading
* register new socket family
* basic smc socket creation and deletion
* use backing TCP socket to run CLC (Connection Layer Control)
handshake of SMC protocol
* Setup for infiniband traffic is implemented in follow-on patches.
For now fallback to TCP socket is always used.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Reviewed-by: Utz Bacher <utz.bacher@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>