linux-dev/drivers/firmware/arm_scmi/notify.c, branch linus/master

firmware: arm_scmi: Fix kernel doc warnings about return values

2021-07-13T10:39:54Z

Kernel doc validation script still complains about the following: |No description found for return value of 'scmi_get_protocol_device' |No description found for return value of 'scmi_devm_notifier_register' |No description found for return value of 'scmi_devm_notifier_unregister' Fix adding missing Return kernel-doc statements. Link: https://lore.kernel.org/r/20210712143504.33541-1-cristian.marussi@arm.com Signed-off-by: Cristian Marussi Signed-off-by: Sudeep Holla

firmware: arm_scmi: Rename non devres notify_ops

2021-03-30T15:35:16Z

Rename non devres managed notify_ops to use a naming pattern which exposes the performed action verb as last token. No functional change. Link: https://lore.kernel.org/r/20210316124903.35011-37-cristian.marussi@arm.com Tested-by: Florian Fainelli Signed-off-by: Cristian Marussi Signed-off-by: Sudeep Holla

firmware: arm_scmi: Make notify_priv really private

2021-03-30T15:35:15Z

Notification private data is currently accessible via handle->notify_priv, this data was indeed meant to be private to the notification core support and not to be accessible by SCMI drivers. Make it private hiding it inside instance descriptor struct scmi_info and accessible only via dedicated helpers. Link: https://lore.kernel.org/r/20210316124903.35011-36-cristian.marussi@arm.com Tested-by: Florian Fainelli Signed-off-by: Cristian Marussi Signed-off-by: Sudeep Holla

firmware: arm_scmi: Convert events registration to protocol handles

2021-03-29T09:00:35Z

Convert all refactored events registration routines to use protocol handles. In order to maintain bisectability and to allow protocols and drivers to be later ported to the new protocol handle interface one by one, introduce here also some transient code that will be removed later in order to ease such transition. Link: https://lore.kernel.org/r/20210316124903.35011-8-cristian.marussi@arm.com Tested-by: Florian Fainelli Signed-off-by: Cristian Marussi Signed-off-by: Sudeep Holla

firmware: arm_scmi: Refactor events registration

2021-03-29T09:00:35Z

Add a new refactored protocol events registration helper and invoke it from the centralized initialization process triggered by get_ops() and friends. Also add a `get_num_sources` as a new optional callback amongst protocol events operations. Finally remove events registration call-sites from within the legacy protocol init routines. Link: https://lore.kernel.org/r/20210316124903.35011-7-cristian.marussi@arm.com Tested-by: Florian Fainelli Signed-off-by: Cristian Marussi Signed-off-by: Sudeep Holla

firmware: arm_scmi: Introduce new devres notification ops

2021-03-29T09:00:35Z

Expose to the SCMI drivers a new alternative devres managed notifications API based on protocol handles. All drivers still keep using the old API, no functional change. Link: https://lore.kernel.org/r/20210316124903.35011-6-cristian.marussi@arm.com Tested-by: Florian Fainelli Signed-off-by: Cristian Marussi Signed-off-by: Sudeep Holla

firmware: arm_scmi: Make notifications aware of protocols users

2021-03-29T09:00:34Z

Account for any active registered notifier against the proper related protocol, do not consider pending event handlers, only active handlers will concur to protocol usage accounting. Link: https://lore.kernel.org/r/20210316124903.35011-5-cristian.marussi@arm.com Tested-by: Florian Fainelli Signed-off-by: Cristian Marussi Signed-off-by: Sudeep Holla

firmware: arm_scmi: Fix missing destroy_workqueue()

2020-11-13T11:16:01Z

destroy_workqueue is required before the return from scmi_notification_init in case devm_kcalloc fails to allocate registered_protocols. Fix this by simply moving registered_protocols allocation before alloc_workqueue. Link: https://lore.kernel.org/r/20201110074221.41235-1-miaoqinglang@huawei.com Fixes: bd31b249692e ("firmware: arm_scmi: Add notification dispatch and delivery") Suggested-by: Cristian Marussi Reviewed-by: Cristian Marussi Signed-off-by: Qinglang Miao Signed-off-by: Sudeep Holla

firmware: arm_scmi: Fix duplicate workqueue name

2020-10-14T17:42:41Z

When more than a single SCMI device are present in the system, the creation of the notification workqueue with the WQ_SYSFS flag will lead to the following sysfs duplicate node warning: sysfs: cannot create duplicate filename '/devices/virtual/workqueue/scmi_notify' CPU: 0 PID: 20 Comm: kworker/0:1 Not tainted 5.9.0-gdf4dd84a3f7d #29 Hardware name: Broadcom STB (Flattened Device Tree) Workqueue: events deferred_probe_work_func Backtrace: show_stack + 0x20/0x24 dump_stack + 0xbc/0xe0 sysfs_warn_dup + 0x70/0x80 sysfs_create_dir_ns + 0x15c/0x1a4 kobject_add_internal + 0x140/0x4d0 kobject_add + 0xc8/0x138 device_add + 0x1dc/0xc20 device_register + 0x24/0x28 workqueue_sysfs_register + 0xe4/0x1f0 alloc_workqueue + 0x448/0x6ac scmi_notification_init + 0x78/0x1dc scmi_probe + 0x268/0x4fc platform_drv_probe + 0x70/0xc8 really_probe + 0x184/0x728 driver_probe_device + 0xa4/0x278 __device_attach_driver + 0xe8/0x148 bus_for_each_drv + 0x108/0x158 __device_attach + 0x190/0x234 device_initial_probe + 0x1c/0x20 bus_probe_device + 0xdc/0xec deferred_probe_work_func + 0xd4/0x11c process_one_work + 0x420/0x8f0 worker_thread + 0x4fc/0x91c kthread + 0x21c/0x22c ret_from_fork + 0x14/0x20 kobject_add_internal failed for scmi_notify with -EEXIST, don't try to register things with the same name in the same directory. arm-scmi brcm_scmi@1: SCMI Notifications - Initialization Failed. arm-scmi brcm_scmi@1: SCMI Notifications NOT available. arm-scmi brcm_scmi@1: SCMI Protocol v1.0 'brcm-scmi:' Firmware version 0x1 Fix this by using dev_name(handle->dev) which guarantees that the name is unique and this also helps correlate which notification workqueue corresponds to which SCMI device instance. Link: https://lore.kernel.org/r/20201014021737.287340-1-f.fainelli@gmail.com Fixes: bd31b249692e ("firmware: arm_scmi: Add notification dispatch and delivery") Signed-off-by: Florian Fainelli [sudeep.holla: trimmed backtrace to remove all unwanted hexcodes and timestamps] Signed-off-by: Sudeep Holla

firmware: arm_scmi: Fix locking in notifications

2020-10-14T17:42:41Z

When a protocol registers its events, the notification core takes care to rescan the hashtable of pending event handlers and activate all the possibly existent handlers referring to any of the events that are just registered by the new protocol. When a pending handler becomes active the core requests and enables the corresponding events in the SCMI firmware. If, for whatever reason, the enable fails, such invalid event handler must be finally removed and freed. Let us ensure to use the scmi_put_active_handler() helper which handles properly the needed additional locking. Failing to properly acquire all the needed mutexes exposes a race that leads to the following splat being observed: WARNING: CPU: 0 PID: 388 at lib/refcount.c:28 refcount_warn_saturate+0xf8/0x148 Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Jun 30 2020 pstate: 40000005 (nZcv daif -PAN -UAO BTYPE=--) pc : refcount_warn_saturate+0xf8/0x148 lr : refcount_warn_saturate+0xf8/0x148 Call trace: refcount_warn_saturate+0xf8/0x148 scmi_put_handler_unlocked.isra.10+0x204/0x208 scmi_put_handler+0x50/0xa0 scmi_unregister_notifier+0x1bc/0x240 scmi_notify_tester_remove+0x4c/0x68 [dummy_scmi_consumer] scmi_dev_remove+0x54/0x68 device_release_driver_internal+0x114/0x1e8 driver_detach+0x58/0xe8 bus_remove_driver+0x88/0xe0 driver_unregister+0x38/0x68 scmi_driver_unregister+0x1c/0x28 scmi_drv_exit+0x1c/0xae0 [dummy_scmi_consumer] __arm64_sys_delete_module+0x1a4/0x268 el0_svc_common.constprop.3+0x94/0x178 do_el0_svc+0x2c/0x98 el0_sync_handler+0x148/0x1a8 el0_sync+0x158/0x180 Link: https://lore.kernel.org/r/20201013133109.49821-1-cristian.marussi@arm.com Fixes: e7c215f358a35 ("firmware: arm_scmi: Add notification callbacks-registration") Signed-off-by: Cristian Marussi Signed-off-by: Sudeep Holla