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path: root/drivers/firmware/arm_ffa/bus.c
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2024-05-29firmware: arm_ffa: Split bus and driver into distinct modulesSudeep Holla
Make the FF-A bus on its own as a distinct module initialized at subsys_initcall level when builtin. Keep the FF-A driver core stack, together with any configured transport, in a different module initialized as module_init level. FF-A drivers initialization is now changed to module_init level. Acked-by: Sebastian Ene <sebastianene@google.com> Link: https://lore.kernel.org/r/20240515094028.1947976-2-sudeep.holla@arm.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2024-05-29firmware: arm_ffa: Move the FF-A v1.0 NULL UUID workaround to bus notifierSudeep Holla
Currently FF-A bus ffa_device_match() handles the workaround for the FF-A v1.0 devices which are not populated with UUID to match. The FF-A bus layer calls into FF-A driver and populates the device UUID if it matches with the driver attempting to match. But this forces to have both FF-A bus and core driver to be bundled into a single module. However, keep it as a single module adds problems for the FF-A driver registrations and their initcall levels. In preparation to split the FF-A bus and the core driver into distinct modules, we need to move the workaround away from the FF-A bus layer. We can add it into the FF-A core driver as a bus notifier. In order to do so, we need to always match any driver with the device if the UUID is NULL and then during the driver binding phase, we can populate the UUID if it matches with the driver UUID table using the bus notifiers. We also need to add a check for NULL UUID before calling the device/driver probe as devices with NULL UUID is possible since we match all for that case. Acked-by: Sebastian Ene <sebastianene@google.com> Link: https://lore.kernel.org/r/20240515094028.1947976-1-sudeep.holla@arm.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2024-02-20firmware: arm_ffa: Make ffa_bus_type constRicardo B. Marliere
Now that the driver core can properly handle constant struct bus_type, move the ffa_bus_type variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net> Reviewed-by: Cristian Marussi <cristian.marussi@arm.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20240211-bus_cleanup-firmware2-v1-1-1851c92c7be7@marliere.net Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-10-06firmware: arm_ffa: Emit modalias for FF-A devicesSudeep Holla
In order to enable libkmod lookups for FF-A device objects to their corresponding module, add 'modalias' to the base attribute of FF-A devices. Tested-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com> Link: https://lore.kernel.org/r/20231005175640.379631-1-sudeep.holla@arm.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-10-06firmware: arm_ffa: Assign the missing IDR allocation ID to the FFA deviceSudeep Holla
Commit 19b8766459c4 ("firmware: arm_ffa: Fix FFA device names for logical partitions") added an ID to the FFA device using ida_alloc() and append the same to "arm-ffa" to make up a unique device name. However it missed to stash the id value in ffa_dev to help freeing the ID later when the device is destroyed. Due to the missing/unassigned ID in FFA device, we get the following warning when the FF-A device is unregistered. | ida_free called for id=0 which is not allocated. | WARNING: CPU: 7 PID: 1 at lib/idr.c:525 ida_free+0x114/0x164 | CPU: 7 PID: 1 Comm: swapper/0 Not tainted 6.6.0-rc4 #209 | pstate: 61400009 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) | pc : ida_free+0x114/0x164 | lr : ida_free+0x114/0x164 | Call trace: | ida_free+0x114/0x164 | ffa_release_device+0x24/0x3c | device_release+0x34/0x8c | kobject_put+0x94/0xf8 | put_device+0x18/0x24 | klist_devices_put+0x14/0x20 | klist_next+0xc8/0x114 | bus_for_each_dev+0xd8/0x144 | arm_ffa_bus_exit+0x30/0x54 | ffa_init+0x68/0x330 | do_one_initcall+0xdc/0x250 | do_initcall_level+0x8c/0xac | do_initcalls+0x54/0x94 | do_basic_setup+0x1c/0x28 | kernel_init_freeable+0x104/0x170 | kernel_init+0x20/0x1a0 | ret_from_fork+0x10/0x20 Fix the same by actually assigning the ID in the FFA device this time for real. Fixes: 19b8766459c4 ("firmware: arm_ffa: Fix FFA device names for logical partitions") Link: https://lore.kernel.org/r/20231003085932.3553985-1-sudeep.holla@arm.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-05-08firmware: arm_ffa: Fix FFA device names for logical partitionsSudeep Holla
Each physical partition can provide multiple services each with UUID. Each such service can be presented as logical partition with a unique combination of VM ID and UUID. The number of distinct UUID in a system will be less than or equal to the number of logical partitions. However, currently it fails to register more than one logical partition or service within a physical partition as the device name contains only VM ID while both VM ID and UUID are maintained in the partition information. The kernel complains with the below message: | sysfs: cannot create duplicate filename '/devices/arm-ffa-8001' | CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.3.0-rc7 #8 | Hardware name: FVP Base RevC (DT) | Call trace: | dump_backtrace+0xf8/0x118 | show_stack+0x18/0x24 | dump_stack_lvl+0x50/0x68 | dump_stack+0x18/0x24 | sysfs_create_dir_ns+0xe0/0x13c | kobject_add_internal+0x220/0x3d4 | kobject_add+0x94/0x100 | device_add+0x144/0x5d8 | device_register+0x20/0x30 | ffa_device_register+0x88/0xd8 | ffa_setup_partitions+0x108/0x1b8 | ffa_init+0x2ec/0x3a4 | do_one_initcall+0xcc/0x240 | do_initcall_level+0x8c/0xac | do_initcalls+0x54/0x94 | do_basic_setup+0x1c/0x28 | kernel_init_freeable+0x100/0x16c | kernel_init+0x20/0x1a0 | ret_from_fork+0x10/0x20 | kobject_add_internal failed for arm-ffa-8001 with -EEXIST, don't try to | register things with the same name in the same directory. | arm_ffa arm-ffa: unable to register device arm-ffa-8001 err=-17 | ARM FF-A: ffa_setup_partitions: failed to register partition ID 0x8001 By virtue of being random enough to avoid collisions when generated in a distributed system, there is no way to compress UUID keys to the number of bits required to identify each. We can eliminate '-' in the name but it is not worth eliminating 4 bytes and add unnecessary logic for doing that. Also v1.0 doesn't provide the UUID of the partitions which makes it hard to use the same for the device name. So to keep it simple, let us alloc an ID using ida_alloc() and append the same to "arm-ffa" to make up a unique device name. Also stash the id value in ffa_dev to help freeing the ID later when the device is destroyed. Fixes: e781858488b9 ("firmware: arm_ffa: Add initial FFA bus support for device enumeration") Reported-by: Lucian Paul-Trifu <lucian.paul-trifu@arm.com> Link: https://lore.kernel.org/r/20230419-ffa_fixes_6-4-v2-3-d9108e43a176@arm.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-05-08firmware: arm_ffa: Check if ffa_driver remove is present before executingSudeep Holla
Currently ffa_drv->remove() is called unconditionally from ffa_device_remove(). Since the driver registration doesn't check for it and allows it to be registered without .remove callback, we need to check for the presence of it before executing it from ffa_device_remove() to above a NULL pointer dereference like the one below: | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 | Mem abort info: | ESR = 0x0000000086000004 | EC = 0x21: IABT (current EL), IL = 32 bits | SET = 0, FnV = 0 | EA = 0, S1PTW = 0 | FSC = 0x04: level 0 translation fault | user pgtable: 4k pages, 48-bit VAs, pgdp=0000000881cc8000 | [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 | Internal error: Oops: 0000000086000004 [#1] PREEMPT SMP | CPU: 3 PID: 130 Comm: rmmod Not tainted 6.3.0-rc7 #6 | Hardware name: FVP Base RevC (DT) | pstate: 63402809 (nZCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=-c) | pc : 0x0 | lr : ffa_device_remove+0x20/0x2c | Call trace: | 0x0 | device_release_driver_internal+0x16c/0x260 | driver_detach+0x90/0xd0 | bus_remove_driver+0xdc/0x11c | driver_unregister+0x30/0x54 | ffa_driver_unregister+0x14/0x20 | cleanup_module+0x18/0xeec | __arm64_sys_delete_module+0x234/0x378 | invoke_syscall+0x40/0x108 | el0_svc_common+0xb4/0xf0 | do_el0_svc+0x30/0xa4 | el0_svc+0x2c/0x7c | el0t_64_sync_handler+0x84/0xf0 | el0t_64_sync+0x190/0x194 Fixes: 244f5d597e1e ("firmware: arm_ffa: Add missing remove callback to ffa_bus_type") Link: https://lore.kernel.org/r/20230419-ffa_fixes_6-4-v2-1-d9108e43a176@arm.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-01-27driver core: make struct bus_type.uevent() take a const *Greg Kroah-Hartman
The uevent() callback in struct bus_type should not be modifying the device that is passed into it, so mark it as a const * and propagate the function signature changes out into all relevant subsystems that use this callback. Acked-by: Rafael J. Wysocki <rafael@kernel.org> Acked-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-08firmware: arm_ffa: Rename ffa_dev_ops as ffa_opsSudeep Holla
Except the message APIs, all other APIs are ffa_device independent and can be used without any associated ffa_device from a non ffa_driver. In order to reflect the same, just rename ffa_dev_ops as ffa_ops to avoid any confusion or to keep it simple. Link: https://lore.kernel.org/r/20220907145240.1683088-8-sudeep.holla@arm.com Suggested-by: Sumit Garg <sumit.garg@linaro.org> Reviewed-by: Sumit Garg <sumit.garg@linaro.org> Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2022-09-08firmware: arm_ffa: Add pointer to the ffa_dev_ops in struct ffa_devSudeep Holla
Currently ffa_dev_ops_get() is the way to fetch the ffa_dev_ops pointer. It checks if the ffa_dev structure pointer is valid before returning the ffa_dev_ops pointer. Instead, the pointer can be made part of the ffa_dev structure and since the core driver is incharge of creating ffa_device for each identified partition, there is no need to check for the validity explicitly if the pointer is embedded in the structure. Add the pointer to the ffa_dev_ops in the ffa_dev structure itself and initialise the same as part of creation of the device. Link: https://lore.kernel.org/r/20220907145240.1683088-2-sudeep.holla@arm.com Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-10-05firmware: arm_ffa: Fix __ffa_devices_unregisterSudeep Holla
When arm_ffa firmware driver module is unloaded or removed we call __ffa_devices_unregister on all the devices on the ffa bus. It must unregister all the devices instead it is currently just releasing the devices without unregistering. That is pure wrong as when we try to load the module back again, it will result in the kernel crash something like below. -->8 CPU: 2 PID: 232 Comm: modprobe Not tainted 5.15.0-rc2+ #169 Hardware name: FVP Base RevC (DT) Call trace: dump_backtrace+0x0/0x1cc show_stack+0x18/0x64 dump_stack_lvl+0x64/0x7c dump_stack+0x18/0x38 sysfs_create_dir_ns+0xe4/0x140 kobject_add_internal+0x170/0x358 kobject_add+0x94/0x100 device_add+0x178/0x5f0 device_register+0x20/0x30 ffa_device_register+0x80/0xcc [ffa_module] ffa_setup_partitions+0x7c/0x108 [ffa_module] init_module+0x290/0x2dc [ffa_module] do_one_initcall+0xbc/0x230 do_init_module+0x58/0x304 load_module+0x15e0/0x1f68 __arm64_sys_finit_module+0xb8/0xf4 invoke_syscall+0x44/0x140 el0_svc_common+0xb4/0xf0 do_el0_svc+0x24/0x80 el0_svc+0x20/0x50 el0t_64_sync_handler+0x84/0xe4 el0t_64_sync+0x1a0/0x1a4 kobject_add_internal failed for arm-ffa-8001 with -EEXIST, don't try to register things with the same name in the same directory. ---- Fix the issue by calling device_unregister in __ffa_devices_unregister which will also take care of calling device_release(which is mapped to ffa_release_device) Link: https://lore.kernel.org/r/20210924092859.3057562-2-sudeep.holla@arm.com Fixes: e781858488b9 ("firmware: arm_ffa: Add initial FFA bus support for device enumeration") Tested-by: Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-10-05firmware: arm_ffa: Add missing remove callback to ffa_bus_typeSudeep Holla
Currently the arm_ffa firmware driver can be built as module and hence all the users of FFA driver. If any driver on the ffa bus is removed or unregistered, the remove callback on all the device bound to the driver being removed should be callback. For that to happen, we must register a remove callback on the ffa_bus which is currently missing. This results in the probe getting called again without the previous remove callback on a device which may result in kernel crash. Fix the issue by registering the remove callback on the FFA bus. Link: https://lore.kernel.org/r/20210924092859.3057562-1-sudeep.holla@arm.com Fixes: e781858488b9 ("firmware: arm_ffa: Add initial FFA bus support for device enumeration") Reported-by: Jens Wiklander <jens.wiklander@linaro.org> Tested-by: Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-07-12firmware: arm_ffa: Simplify probe functionUwe Kleine-König
When the driver core calls the probe callback it already checked that the devices match, so there is no need to call the match callback again. Link: https://lore.kernel.org/r/20210621201652.127611-2-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-07-12firmware: arm_ffa: Ensure drivers provide a probe functionUwe Kleine-König
The bus probe callback calls the driver callback without further checking. Better be safe than sorry and refuse registration of a driver without a probe function to prevent a NULL pointer exception. Link: https://lore.kernel.org/r/20210621201652.127611-1-u.kleine-koenig@pengutronix.de Fixes: e781858488b9 ("firmware: arm_ffa: Add initial FFA bus support for device enumeration") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-05-26firmware: arm_ffa: Setup in-kernel users of FFA partitionsSudeep Holla
Parse the FFA nodes from the device-tree and register all the partitions whose services will be used in the kernel. In order to also enable in-kernel users of FFA interface, let us add simple set of operations for such devices. The in-kernel users are registered without the character device interface. Link: https://lore.kernel.org/r/20210521151033.181846-5-sudeep.holla@arm.com Tested-by: Jens Wiklander <jens.wiklander@linaro.org> Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-05-26firmware: arm_ffa: Add initial Arm FFA driver supportSudeep Holla
This just add a basic driver that sets up the transport(e.g. SMCCC), checks the FFA version implemented, get the partition ID for self and sets up the Tx/Rx buffers for communication. Link: https://lore.kernel.org/r/20210521151033.181846-3-sudeep.holla@arm.com Tested-by: Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-05-26firmware: arm_ffa: Add initial FFA bus support for device enumerationSudeep Holla
The Arm FF for Armv8-A specification has concept of endpoints or partitions. In the Normal world, a partition could be a VM when the Virtualization extension is enabled or the kernel itself. In order to handle multiple partitions, we can create a FFA device for each such partition on a dedicated FFA bus. Similarly, different drivers requiring FFA transport can be registered on the same bus. We can match the device and drivers using UUID. This is mostly for the in-kernel users with FFA drivers. Link: https://lore.kernel.org/r/20210521151033.181846-2-sudeep.holla@arm.com Tested-by: Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>