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path: root/drivers/firmware/arm_scmi/bus.c
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2021-07-21bus: Make remove callback return voidUwe Kleine-König1-3/+1
The driver core ignores the return value of this callback because there is only little it can do when a device disappears. This is the final bit of a long lasting cleanup quest where several buses were converted to also return void from their remove callback. Additionally some resource leaks were fixed that were caused by drivers returning an error code in the expectation that the driver won't go away. With struct bus_type::remove returning void it's prevented that newly implemented buses return an ignored error code and so don't anticipate wrong expectations for driver authors. Reviewed-by: Tom Rix <trix@redhat.com> (For fpga) Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> (For drivers/s390 and drivers/vfio) Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> (For ARM, Amba and related parts) Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb) Acked-by: Pali Rohár <pali@kernel.org> Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> (for media) Acked-by: Hans de Goede <hdegoede@redhat.com> (For drivers/platform) Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-By: Vinod Koul <vkoul@kernel.org> Acked-by: Juergen Gross <jgross@suse.com> (For xen) Acked-by: Lee Jones <lee.jones@linaro.org> (For mfd) Acked-by: Johannes Thumshirn <jth@kernel.org> (For mcb) Acked-by: Johan Hovold <johan@kernel.org> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> (For slimbus) Acked-by: Kirti Wankhede <kwankhede@nvidia.com> (For vfio) Acked-by: Maximilian Luz <luzmaximilian@gmail.com> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> (For ulpi and typec) Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> (For ipack) Acked-by: Geoff Levand <geoff@infradead.org> (For ps3) Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> (For thunderbolt) Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> (For intel_th) Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> (For pcmcia) Acked-by: Rafael J. Wysocki <rafael@kernel.org> (For ACPI) Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> (rpmsg and apr) Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> (For intel-ish-hid) Acked-by: Dan Williams <dan.j.williams@intel.com> (For CXL, DAX, and NVDIMM) Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> (For isa) Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (For firewire) Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> (For hid) Acked-by: Thorsten Scherer <t.scherer@eckelmann.de> (For siox) Acked-by: Sven Van Asbroeck <TheSven73@gmail.com> (For anybuss) Acked-by: Ulf Hansson <ulf.hansson@linaro.org> (For MMC) Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C Acked-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Finn Thain <fthain@linux-m68k.org> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-12firmware: arm_scmi: Ensure drivers provide a probe functionSudeep Holla1-0/+3
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/20210624095059.4010157-2-sudeep.holla@arm.com Fixes: 933c504424a2 ("firmware: arm_scmi: add scmi protocol bus to enumerate protocol devices") Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Tested-by: Cristian Marussi <cristian.marussi@arm.com> Reviewed-by: Cristian Marussi <cristian.marussi@arm.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-07-12firmware: arm_scmi: Simplify device probe function on the busSudeep Holla1-5/+0
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/20210624095059.4010157-1-sudeep.holla@arm.com Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Tested-by: Cristian Marussi <cristian.marussi@arm.com> Reviewed-by: Cristian Marussi <cristian.marussi@arm.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-03-30firmware: arm_scmi: Add dynamic scmi devices creationCristian Marussi1-0/+30
Having added the support for SCMI protocols as modules in order to let vendors extend the SCMI core with their own additions it seems odd to then force SCMI drivers built on top to use a static device table to declare their devices since this way any new SCMI drivers addition would need the core SCMI device table to be updated too. Remove the static core device table and let SCMI drivers to simply declare which device/protocol pair they need at initialization time: the core will then take care to generate such devices dynamically during platform initialization or at module loading time, as long as the requested underlying protocol is defined in the devicetree. Link: https://lore.kernel.org/r/20210316124903.35011-39-cristian.marussi@arm.com Tested-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-03-30firmware: arm_scmi: Add protocol modularization supportCristian Marussi1-1/+10
Extend SCMI protocols accounting mechanism to address possible module usage and add the support to possibly define new protocols as loadable modules. Keep the standard protocols built into the SCMI core. Link: https://lore.kernel.org/r/20210316124903.35011-38-cristian.marussi@arm.com Tested-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-03-30firmware: arm_scmi: Cleanup legacy protocol init codeCristian Marussi1-25/+1
Now that all protocols and drivers have been ported to the new interface based on protocol handles and get/put operations, remove all the legacy transient initialization code. Link: https://lore.kernel.org/r/20210316124903.35011-33-cristian.marussi@arm.com Tested-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-03-29firmware: arm_scmi: Extend protocol registration interfacesCristian Marussi1-12/+47
Extend common protocol registration routines and provide some new generic protocols get/put helpers that can track protocols usage and automatically perform the proper initialization and de-initialization on demand when required. Convert all standard protocols to use this new registration scheme while keeping them all still using the usual initialization logic bound to SCMI devices probing. Link: https://lore.kernel.org/r/20210316124903.35011-2-cristian.marussi@arm.com Tested-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-09-14firmware: arm_scmi: Move scmi bus init and exit calls into the driverSudeep Holla1-4/+2
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 Holla1-0/+9
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 Holla1-3/+17
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 Yang1-4/+4
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 Holla1-2/+7
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 Holla1-10/+12
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 Holla1-0/+221
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>