linux-stable.git/net/smc/Kconfig, branch linux-rolling-stable

net: smc: SMC_HS_CTRL_BPF should depend on BPF_JIT

2025-12-04T19:07:18+00:00

If CONFIG_BPF_SYSCALL=y, but CONFIG_BPF_JIT=n:

    net/smc/smc_hs_bpf.c: In function ‘bpf_smc_hs_ctrl_init’:
    include/linux/bpf.h:2068:50: error: statement with no effect [-Werror=unused-value]
     2068 | #define register_bpf_struct_ops(st_ops, type) ({ (void *)(st_ops); 0; })
	  |                                                  ^~~~~~~~~~~~~~~~
    net/smc/smc_hs_bpf.c:139:16: note: in expansion of macro ‘register_bpf_struct_ops’
      139 |         return register_bpf_struct_ops(&bpf_smc_hs_ctrl_ops, smc_hs_ctrl);
	  |                ^~~~~~~~~~~~~~~~~~~~~~~

While this compile error is caused by a bug in , none of
the code in net/smc/smc_hs_bpf.c becomes effective if CONFIG_BPF_JIT is
not enabled.  Hence add a dependency on BPF_JIT.

While at it, add the missing newline at the end of the file.

Fixes: 15f295f55656658e ("net/smc: bpf: Introduce generic hook for handshake flow")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Martin KaFai Lau 
Link: https://patch.msgid.link/988c61e5fea280872d81b3640f1f34d0619cfbbf.1764843951.git.geert@linux-m68k.org

net/smc: bpf: Introduce generic hook for handshake flow

2025-11-10T19:19:41+00:00

The introduction of IPPROTO_SMC enables eBPF programs to determine
whether to use SMC based on the context of socket creation, such as
network namespaces, PID and comm name, etc.

As a subsequent enhancement, to introduce a new generic hook that
allows decisions on whether to use SMC or not at runtime, including
but not limited to local/remote IP address or ports.

User can write their own implememtion via bpf_struct_ops now to choose
whether to use SMC or not before TCP 3rd handshake to be comleted.

Signed-off-by: D. Wythe 
Signed-off-by: Martin KaFai Lau 
Reviewed-by: Dust Li 
Link: https://patch.msgid.link/20251107035632.115950-3-alibuda@linux.alibaba.com

dibs: Move event handling to dibs layer

2025-09-23T09:13:22+00:00

Add defines for all event types and subtypes an ism device is known to
produce as it can be helpful for debugging purposes.

Introduces a generic 'struct dibs_event' and adopt ism device driver
and smc-d client accordingly. Tolerate and ignore other type and subtype
values to enable future device extensions.

SMC-D and ISM are now independent.
struct ism_dev can be moved to drivers/s390/net/ism.h.

Note that in smc, the term 'ism' is still used. Future patches could
replace that with 'dibs' or 'smc-d' as appropriate.

Signed-off-by: Julian Ruess 
Co-developed-by: Alexandra Winter 
Signed-off-by: Alexandra Winter 
Link: https://patch.msgid.link/20250918110500.1731261-15-wintera@linux.ibm.com
Signed-off-by: Paolo Abeni

dibs: Define dibs_client_ops and dibs_dev_ops

2025-09-23T09:13:22+00:00

Move the device add() and remove() functions from ism_client to
dibs_client_ops and call add_dev()/del_dev() for ism devices and
dibs_loopback devices. dibs_client_ops->add_dev() = smcd_register_dev() for
the smc_dibs_client. This is the first step to handle ism and loopback
devices alike (as dibs devices) in the smc dibs client.

Define dibs_dev->ops and move smcd_ops->get_chid to
dibs_dev_ops->get_fabric_id() for ism and loopback devices. See below for
why this needs to be in the same patch as dibs_client_ops->add_dev().

The following changes contain intermediate steps, that will be obsoleted by
follow-on patches, once more functionality has been moved to dibs:

Use different smcd_ops and max_dmbs for ism and loopback. Follow-on patches
will change SMC-D to directly use dibs_ops instead of smcd_ops.

In smcd_register_dev() it is now necessary to identify a dibs_loopback
device before smcd_dev and smcd_ops->get_chid() are available. So provide
dibs_dev_ops->get_fabric_id() in this patch and evaluate it in
smc_ism_is_loopback().

Call smc_loopback_init() in smcd_register_dev() and call
smc_loopback_exit() in smcd_unregister_dev() to handle the functionality
that is still in smc_loopback. Follow-on patches will move all smc_loopback
code to dibs_loopback.

In smcd_[un]register_dev() use only ism device name, this will be replaced
by dibs device name by a follow-on patch.

End of changes with intermediate parts.

Allocate an smcd event workqueue for all dibs devices, although
dibs_loopback does not generate events.

Use kernel memory instead of devres memory for smcd_dev and smcd->conn.
Since commit a72178cfe855 ("net/smc: Fix dependency of SMC on ISM") an ism
device and its driver can have a longer lifetime than the smc module, so
smc should not rely on devres to free its resources [1]. It is now the
responsibility of the smc client to free smcd and smcd->conn for all dibs
devices, ism devices as well as loopback. Call client->ops->del_dev() for
all existing dibs devices in dibs_unregister_client(), so all device
related structures can be freed in the client.

When dibs_unregister_client() is called in the context of smc_exit() or
smc_core_reboot_event(), these functions have already called
smc_lgrs_shutdown() which calls smc_smcd_terminate_all(smcd) and sets
going_away. This is done a second time in smcd_unregister_dev(). This is
analogous to how smcr is handled in these functions, by calling first
smc_lgrs_shutdown() and then smc_ib_unregister_client() >
smc_ib_remove_dev(), so leave it that way. It may be worth investigating,
whether smc_lgrs_shutdown() is still required or useful.

Remove CONFIG_SMC_LO. CONFIG_DIBS_LO now controls whether a dibs loopback
device exists or not.

Link: https://www.kernel.org/doc/Documentation/driver-model/devres.txt [1]
Signed-off-by: Alexandra Winter 
Reviewed-by: Mahanta Jambigi 
Link: https://patch.msgid.link/20250918110500.1731261-8-wintera@linux.ibm.com
Signed-off-by: Paolo Abeni

dibs: Register smc as dibs_client

2025-09-23T09:13:21+00:00

Formally register smc as dibs client. Functionality will be moved by
follow-on patches from ism_client to dibs_client until eventually
ism_client can be removed.
As DIBS is only a shim layer without any dependencies, we can depend SMC
on DIBS without adding indirect dependencies. A follow-on patch will
remove dependency of SMC on ISM.

Signed-off-by: Alexandra Winter 
Reviewed-by: Julian Ruess 
Link: https://patch.msgid.link/20250918110500.1731261-5-wintera@linux.ibm.com
Signed-off-by: Paolo Abeni

net/smc: introduce loopback-ism for SMC intra-OS shortcut

2024-04-30T11:24:48+00:00

This introduces a kind of Emulated-ISM device named loopback-ism for
SMCv2.1. The loopback-ism device is currently exclusive for SMC usage,
and aims to provide an SMC shortcut for sockets within the same kernel,
leading to improved intra-OS traffic performance. Configuration of this
feature is managed through the config SMC_LO.

Signed-off-by: Wen Gu 
Reviewed-by: Gerd Bayer 
Reviewed-by: Wenjia Zhang 
Reviewed-and-tested-by: Jan Karcher 
Signed-off-by: Paolo Abeni

net/smc: Fix dependency of SMC on ISM

2023-10-10T09:51:41+00:00

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 
Closes: https://lore.kernel.org/linux-next/d53b5b50-d894-4df8-8969-fd39e63440ae@infradead.org/
Co-developed-by: Wenjia Zhang 
Signed-off-by: Wenjia Zhang 
Signed-off-by: Gerd Bayer 
Reviewed-by: Simon Horman 
Tested-by: Simon Horman  # build-tested
Acked-by: Randy Dunlap 
Tested-by: Randy Dunlap  # build-tested
Link: https://lore.kernel.org/r/20231006125847.1517840-1-gbayer@linux.ibm.com
Signed-off-by: Paolo Abeni

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

2020-06-13T16:57:21+00:00

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

treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21T08:50:46+00:00

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 
Signed-off-by: Greg Kroah-Hartman

net/smc: remove Kconfig warning

2017-07-29T18:22:58+00:00

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 
Signed-off-by: David S. Miller