kernel/linux.git/drivers/base/platform.c, branch v6.6.132

of: Move of_platform_register_reconfig_notifier() into DT core

2023-08-04T17:36:33+00:00

There's no reason the generic platform bus code needs to call of_platform_register_reconfig_notifier(). The notifier can be setup before the platform bus is. Let's move it into of_core_init() which is called just before platform_bus_init() instead to keep more of the DT bits in the DT code. Reviewed-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20230717143718.1715773-1-robh@kernel.org Signed-off-by: Rob Herring

driver core: platform: simplify __platform_driver_probe()

2023-02-01T13:08:10+00:00

__platform_driver_probe() pokes around in some bus and driver private lists and locks in a way that is not needed at all. The code only wants to know if a device was bound to the driver that was registered, so walk all devices on the bus to see if there was a match. If there is not a match, return an error. This is the same logic as was originally present, but just done in a simpler and more obvious way that is not a layering violation. Cc: "Rafael J. Wysocki" Link: https://lore.kernel.org/r/20230131082459.301603-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

driver core: platform: removed unneeded variable from __platform_driver_probe()

2023-02-01T13:08:08+00:00

In the reworking of the function __platform_driver_probe() over the years, it turns out that the variable 'code' does not actually do anything or mean anything anymore and can be removed to simplify the logic when trying to read and understand what this function is actually doing. Cc: "Rafael J. Wysocki" Link: https://lore.kernel.org/r/20230131082459.301603-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

driver core: make struct bus_type.uevent() take a const *

2023-01-27T12:45:52+00:00

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 Acked-by: Hans de Goede Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

platform: remove useless if-branch in __platform_get_irq_byname()

2023-01-17T18:12:48+00:00

When CONFIG_OF_IRQ is not enabled, there will be a stub method that always returns 0 when getting IRQ. Thus, the if-branch can be removed safely. Signed-off-by: Soha Jin Link: https://lore.kernel.org/r/20221111094542.270540-1-soha@lohu.info Signed-off-by: Greg Kroah-Hartman

platform: Document platform_add_devices() return value

2023-01-17T18:12:22+00:00

platform_add_devices() returns 0 on success and negative errno on failure. Document it. Signed-off-by: Umang Jain Link: https://lore.kernel.org/r/20221220085116.19837-1-umang.jain@ideasonboard.com Signed-off-by: Greg Kroah-Hartman

platform: Provide a remove callback that returns no value

2023-01-17T18:04:17+00:00

struct platform_driver::remove returning an integer made driver authors expect that returning an error code was proper error handling. However the driver core ignores the error and continues to remove the device because there is nothing the core could do anyhow and reentering the remove callback again is only calling for trouble. So this is an source for errors typically yielding resource leaks in the error path. As there are too many platform drivers to neatly convert them all to return void in a single go, do it in several steps after this patch: a) Convert all drivers to implement .remove_new() returning void instead of .remove() returning int; b) Change struct platform_driver::remove() to return void and so make it identical to .remove_new(); c) Change all drivers back to .remove() now with the better prototype; d) drop struct platform_driver::remove_new(). While this touches all drivers eventually twice, steps a) and c) can be done one driver after another and so reduces coordination efforts immensely and simplifies review. Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20221209150914.3557650-1-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman

platform: use fwnode_irq_get_byname instead of of_irq_get_byname to get irq

2022-11-10T17:56:47+00:00

Not only platform devices described by OF have named interrupts, but devices described by ACPI also have named interrupts. The fwnode is an abstraction to different standards, and using fwnode_irq_get_byname can support more devices. Signed-off-by: Soha Jin Tested-by: Wende Tan Signed-off-by: Greg Kroah-Hartman

Merge tag 'driver-core-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2022-06-03T18:48:47+00:00

Pull driver core updates from Greg KH: "Here is the set of driver core changes for 5.19-rc1. Lots of tiny driver core changes and cleanups happened this cycle, but the two major things are: - firmware_loader reorganization and additions including the ability to have XZ compressed firmware images and the ability for userspace to initiate the firmware load when it needs to, instead of being always initiated by the kernel. FPGA devices specifically want this ability to have their firmware changed over the lifetime of the system boot, and this allows them to work without having to come up with yet-another-custom-uapi interface for loading firmware for them. - physical location support added to sysfs so that devices that know this information, can tell userspace where they are located in a common way. Some ACPI devices already support this today, and more bus types should support this in the future. Smaller changes include: - driver_override api cleanups and fixes - error path cleanups and fixes - get_abi script fixes - deferred probe timeout changes. It's that last change that I'm the most worried about. It has been reported to cause boot problems for a number of systems, and I have a tested patch series that resolves this issue. But I didn't get it merged into my tree before 5.18-final came out, so it has not gotten any linux-next testing. I'll send the fixup patches (there are 2) as a follow-on series to this pull request. All have been tested in linux-next for weeks, with no reported issues other than the above-mentioned boot time-outs" * tag 'driver-core-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits) driver core: fix deadlock in __device_attach kernfs: Separate kernfs_pr_cont_buf and rename_lock. topology: Remove unused cpu_cluster_mask() driver core: Extend deferred probe timeout on driver registration MAINTAINERS: add Russ Weight as a firmware loader maintainer driver: base: fix UAF when driver_attach failed test_firmware: fix end of loop test in upload_read_show() driver core: location: Add "back" as a possible output for panel driver core: location: Free struct acpi_pld_info *pld driver core: Add "*" wildcard support to driver_async_probe cmdline param driver core: location: Check for allocations failure arch_topology: Trace the update thermal pressure kernfs: Rename kernfs_put_open_node to kernfs_unlink_open_file. export: fix string handling of namespace in EXPORT_SYMBOL_NS rpmsg: use local 'dev' variable rpmsg: Fix calling device_lock() on non-initialized device firmware_loader: describe 'module' parameter of firmware_upload_register() firmware_loader: Move definitions from sysfs_upload.h to sysfs.h firmware_loader: Fix configs for sysfs split selftests: firmware: Add firmware upload selftests ...

bus: platform,amba,fsl-mc,PCI: Add device DMA ownership management

2022-04-28T13:32:20+00:00

The devices on platform/amba/fsl-mc/PCI buses could be bound to drivers with the device DMA managed by kernel drivers or user-space applications. Unfortunately, multiple devices may be placed in the same IOMMU group because they cannot be isolated from each other. The DMA on these devices must either be entirely under kernel control or userspace control, never a mixture. Otherwise the driver integrity is not guaranteed because they could access each other through the peer-to-peer accesses which by-pass the IOMMU protection. This checks and sets the default DMA mode during driver binding, and cleanups during driver unbinding. In the default mode, the device DMA is managed by the device driver which handles DMA operations through the kernel DMA APIs (see Documentation/core-api/dma-api.rst). For cases where the devices are assigned for userspace control through the userspace driver framework(i.e. VFIO), the drivers(for example, vfio_pci/ vfio_platfrom etc.) may set a new flag (driver_managed_dma) to skip this default setting in the assumption that the drivers know what they are doing with the device DMA. Calling iommu_device_use_default_domain() before {of,acpi}_dma_configure is currently a problem. As things stand, the IOMMU driver ignored the initial iommu_probe_device() call when the device was added, since at that point it had no fwspec yet. In this situation, {of,acpi}_iommu_configure() are retriggering iommu_probe_device() after the IOMMU driver has seen the firmware data via .of_xlate to learn that it actually responsible for the given device. As the result, before that gets fixed, iommu_use_default_domain() goes at the end, and calls arch_teardown_dma_ops() if it fails. Cc: Greg Kroah-Hartman Cc: Bjorn Helgaas Cc: Stuart Yoder Cc: Laurentiu Tudor Signed-off-by: Lu Baolu Reviewed-by: Greg Kroah-Hartman Reviewed-by: Jason Gunthorpe Reviewed-by: Robin Murphy Tested-by: Eric Auger Link: https://lore.kernel.org/r/20220418005000.897664-5-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel