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2025-09-23dibs: Move event handling to dibs layerJulian Ruess1-0/+62
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 <julianr@linux.ibm.com> Co-developed-by: Alexandra Winter <wintera@linux.ibm.com> Signed-off-by: Alexandra Winter <wintera@linux.ibm.com> Link: https://patch.msgid.link/20250918110500.1731261-15-wintera@linux.ibm.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-23dibs: Move data path to dibs layerAlexandra Winter1-0/+177
Use struct dibs_dmb instead of struct smc_dmb and move the corresponding client tables to dibs_dev. Leave driver specific implementation details like sba in the device drivers. Register and unregister dmbs via dibs_dev_ops. A dmb is dedicated to a single client, but a dibs device can have dmbs for more than one client. Trigger dibs clients via dibs_client_ops->handle_irq(), when data is received into a dmb. For dibs_loopback replace scheduling an smcd receive tasklet with calling dibs_client_ops->handle_irq(). For loopback devices attach_dmb(), detach_dmb() and move_data() need to access the dmb tables, so move those to dibs_dev_ops in this patch as well. Remove remaining definitions of smc_loopback as they are no longer required, now that everything is in dibs_loopback. Note that struct ism_client and struct ism_dev are still required in smc until a follow-on patch moves event handling to dibs. (Loopback does not use events). Signed-off-by: Alexandra Winter <wintera@linux.ibm.com> Link: https://patch.msgid.link/20250918110500.1731261-14-wintera@linux.ibm.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-23dibs: Move query_remote_gid() to dibs_dev_opsAlexandra Winter1-0/+14
Provide the dibs_dev_ops->query_remote_gid() in ism and dibs_loopback dibs_devices. And call it in smc dibs_client. Reviewed-by: Julian Ruess <julianr@linux.ibm.com> Signed-off-by: Alexandra Winter <wintera@linux.ibm.com> Link: https://patch.msgid.link/20250918110500.1731261-13-wintera@linux.ibm.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-23dibs: Move vlan support to dibs_dev_opsAlexandra Winter1-0/+19
It can be debated how much benefit definition of vlan ids for dibs devices brings, as the dmbs are accessible only by a single peer anyhow. But ism provides vlan support and smcd exploits it, so move it to dibs layer as an optional feature. smcd_loopback simply ignores all vlan settings, do the same in dibs_loopback. SMC-D and ISM have a method to use the invalid VLAN ID 1FFF (ISM_RESERVED_VLANID), to indicate that both communication peers support routable SMC-Dv2. Tolerate it in dibs, but move it to SMC only. Signed-off-by: Alexandra Winter <wintera@linux.ibm.com> Link: https://patch.msgid.link/20250918110500.1731261-12-wintera@linux.ibm.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-23dibs: Local gid for dibs devicesAlexandra Winter1-0/+3
Define a uuid_t GID attribute to identify a dibs device. SMC uses 64 Bit and 128 Bit Global Identifiers (GIDs) per device, that need to be sent via the SMC protocol. Because the smc code uses integers, network endianness and host endianness need to be considered. Avoid this in the dibs layer by using uuid_t byte arrays. Future patches could change SMC to use uuid_t. For now conversion helper functions are introduced. ISM devices provide 64 Bit GIDs. Map them to dibs uuid_t GIDs like this: _________________________________________ | 64 Bit ISM-vPCI GID | 00000000_00000000 | ----------------------------------------- If interpreted as UUID [1], this would be interpreted as the UIID variant, that is reserved for NCS backward compatibility. So it will not collide with UUIDs that were generated according to the standard. smc_loopback already uses version 4 UUIDs as 128 Bit GIDs, move that to dibs loopback. A temporary change to smc_lo_query_rgid() is required, that will be moved to dibs_loopback with a follow-on patch. Provide gid of a dibs device as sysfs read-only attribute. Link: https://datatracker.ietf.org/doc/html/rfc4122 [1] Signed-off-by: Alexandra Winter <wintera@linux.ibm.com> Reviewed-by: Julian Ruess <julianr@linux.ibm.com> Reviewed-by: Mahanta Jambigi <mjambigi@linux.ibm.com> Link: https://patch.msgid.link/20250918110500.1731261-11-wintera@linux.ibm.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-23dibs: Move struct device to dibs_devJulian Ruess1-0/+1
Move struct device from ism_dev and smc_lo_dev to dibs_dev, and define a corresponding release function. Free ism_dev in ism_remove() and smc_lo_dev in smc_lo_dev_remove(). Replace smcd->ops->get_dev(smcd) by using dibs->dev directly. An alternative design would be to embed dibs_dev as a field in ism_dev and do the same for other dibs device driver specific structs. However that would have the disadvantage that each dibs device driver needs to allocate dibs_dev and each dibs device driver needs a different device release function. The advantage would be that ism_dev and other device driver specific structs would be covered by device reference counts. Signed-off-by: Julian Ruess <julianr@linux.ibm.com> Co-developed-by: Alexandra Winter <wintera@linux.ibm.com> Signed-off-by: Alexandra Winter <wintera@linux.ibm.com> Reviewed-by: Mahanta Jambigi <mjambigi@linux.ibm.com> Link: https://patch.msgid.link/20250918110500.1731261-9-wintera@linux.ibm.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-23dibs: Define dibs_client_ops and dibs_dev_opsAlexandra Winter1-2/+87
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 <wintera@linux.ibm.com> Reviewed-by: Mahanta Jambigi <mjambigi@linux.ibm.com> Link: https://patch.msgid.link/20250918110500.1731261-8-wintera@linux.ibm.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-23dibs: Register ism as dibs deviceAlexandra Winter1-0/+38
Register ism devices with the dibs layer. Follow-on patches will move functionality to the dibs layer. As DIBS is only a shim layer without any dependencies, we can depend ISM on DIBS without adding indirect dependencies. A follow-on patch will remove implication of SMC by ISM. Define struct dibs_dev. Follow-on patches will move more content into dibs_dev. The goal of follow-on patches is that ism_dev will only contain fields that are special for this device driver. The same concept will apply to other dibs device drivers. Define dibs_dev_alloc(), dibs_dev_add() and dibs_dev_del() to be called by dibs device drivers and call them from ism_drv.c Use ism_dev.dibs for a pointer to dibs_dev. Signed-off-by: Alexandra Winter <wintera@linux.ibm.com> Link: https://patch.msgid.link/20250918110500.1731261-6-wintera@linux.ibm.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-23dibs: Register smc as dibs_clientAlexandra Winter1-0/+23
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 <wintera@linux.ibm.com> Reviewed-by: Julian Ruess <julianr@linux.ibm.com> Link: https://patch.msgid.link/20250918110500.1731261-5-wintera@linux.ibm.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-23dibs: Create drivers/dibsAlexandra Winter1-0/+42
Create the file structure for a 'DIBS - Direct Internal Buffer Sharing' shim layer that will provide generic functionality and declarations for dibs device drivers and dibs clients. Following patches will add functionality. Signed-off-by: Alexandra Winter <wintera@linux.ibm.com> Link: https://patch.msgid.link/20250918110500.1731261-4-wintera@linux.ibm.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>