summaryrefslogtreecommitdiff
path: root/drivers/firmware/arm_scmi/bus.c
AgeCommit message (Collapse)Author
2020-09-14firmware: arm_scmi: Move scmi bus init and exit calls into the driverSudeep Holla
In preparation to enable building scmi as a single module, let us move the scmi bus {de-,}initialisation call into the driver. The main reason for this is to keep it simple instead of maintaining it as separate modules and dealing with all possible initcall races and deferred probe handling. We can move it as separate modules if needed in future. Link: https://lore.kernel.org/r/20200907195046.56615-3-sudeep.holla@arm.com Tested-by: Cristian Marussi <cristian.marussi@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-12-24firmware: arm_scmi: Skip protocol initialisation for additional devicesSudeep Holla
The scmi bus now supports adding multiple devices per protocol, and since scmi_protocol_init is called for each scmi device created, we must avoid allocating protocol private data and initialising the protocol itself if it is already initialised. In order to achieve the same, we can simple replace the idr pointer from protocol initialisation function to a dummy function. Suggested-by: Cristian Marussi <cristian.marussi@arm.com> Reviewed-by: Cristian Marussi <cristian.marussi@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-12-24firmware: arm_scmi: Add support for multiple device per protocolSudeep Holla
Currently only one scmi device is created for each protocol enumerated. However, there is requirement to make use of some procotols by multiple kernel subsystems/frameworks. One such example is SCMI PERFORMANCE protocol which can be used by both cpufreq and devfreq drivers. Similarly, SENSOR protocol may be used by hwmon and iio subsystems, and POWER protocol may be used by genpd and regulator drivers. In order to achieve that, let us extend the scmi bus to match based not only protocol id but also the scmi device name if one is available. Reviewed-by: Cristian Marussi <cristian.marussi@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-11-26firmware: arm_scmi: Avoid double free in error flowWen Yang
If device_register() fails, both put_device() and kfree() are called, ending with a double free of the scmi_dev. Calling kfree() is needed only when a failure happens between the allocation of the scmi_dev and its registration, so move it to there and remove it from the error flow. Fixes: 46edb8d1322c ("firmware: arm_scmi: provide the mandatory device release callback") Signed-off-by: Wen Yang <wenyang@linux.alibaba.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-01-30firmware: arm_scmi: provide the mandatory device release callbackSudeep Holla
The device/driver model clearly mandates that bus driver that discover and allocate the device must set the release callback. This callback will be used to free the device after all references have gone away. scmi bus driver is missing the obvious callback which will result in the following warning if the device is unregistered: Device 'scmi_dev.1' does not have a release() function, it is broken and must be fixed. See Documentation/kobject.txt. WARNING at drivers/base/core.c:922 device_release+0x8c/0xa0 Hardware name: ARM LTD Juno Development Platform BIOS EDK II Jan 21 2019 Workqueue: events deferred_probe_work_func pstate: 60000005 (nZCv daif -PAN -UAO) pc : device_release+0x8c/0xa0 lr : device_release+0x8c/0xa0 Call trace: device_release+0x8c/0xa0 kobject_put+0x8c/0x208 device_unregister+0x30/0x78 scmi_device_destroy+0x28/0x50 scmi_probe+0x354/0x5b0 platform_drv_probe+0x58/0xa8 really_probe+0x2c4/0x3e8 driver_probe_device+0x12c/0x148 __device_attach_driver+0xac/0x150 bus_for_each_drv+0x78/0xd8 __device_attach+0xe0/0x168 device_initial_probe+0x24/0x30 bus_probe_device+0xa0/0xa8 deferred_probe_work_func+0x8c/0xe0 process_one_work+0x1f0/0x478 worker_thread+0x22c/0x450 kthread+0x134/0x138 ret_from_fork+0x10/0x1c ---[ end trace 420bdb7f6af50937 ]--- Fix the issue by providing scmi_device_release callback. We have everything required for device release already in scmi_device_destroy, so we just need to move freeing of the device to scmi_device_release. Fixes: 933c504424a2 ("firmware: arm_scmi: add scmi protocol bus to enumerate protocol devices") Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Cc: stable@vger.kernel.org # 4.17+ Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-05-10firmware: arm_scmi: improve exit paths and code readabilitySudeep Holla
The existing code intends the good path to reduce the code which is so uncommon. It's obvious to have more readable code with a goto used for the error path. This patch adds more appropriate error paths and makes code more readable. It also moves a error logging outside the scope of locking. Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2018-02-28firmware: arm_scmi: add scmi protocol bus to enumerate protocol devicesSudeep Holla
The SCMI specification encompasses various protocols. However, not every protocol has to be present on a given platform/implementation as not every protocol is relevant for it. Furthermore, the platform chooses which protocols it exposes to a given agent. The only protocol that must be implemented is the base protocol. The base protocol is used by an agent to discover which protocols are available to it. In order to enumerate the discovered implemented protocols, this patch adds support for a separate scmi protocol bus. It also adds mechanism to register support for different protocols. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>