kernel/linux.git/drivers/fpga/dfl.c, branch v6.18.22

fpga: dfl: use subsys_initcall to allow built-in drivers to be added

2026-03-04T12:20:54+00:00

[ Upstream commit 267f53140c9d0bf270bbe0148082e9b8e5011273 ] The dfl code adds a bus. If it is built-in and there is a built-in driver as well, the dfl module_init may be called after the driver module_init, leading to a failure to register the driver as the bus has not been added yet. Use subsys_initcall, which guarantees it will be called before the drivers init code. Without the fix, we see failures like this: [ 0.479475] Driver 'intel-m10-bmc' was unable to register with bus_type 'dfl' because the bus was not initialized. Cc: stable@vger.kernel.org Fixes: 9ba3a0aa09fe ("fpga: dfl: create a dfl bus type to support DFL devices") Signed-off-by: Thadeu Lima de Souza Cascardo Link: https://lore.kernel.org/r/20251215-dfl_subsys-v1-1-21807bad6b10@igalia.com Reviewed-by: Xu Yilun Signed-off-by: Xu Yilun Signed-off-by: Sasha Levin

fpga: dfl: destroy/recreate feature platform device on port release/assign

2024-12-18T14:28:48+00:00

Now that the internal DFL APIs have been converted to consume DFL enumeration info from a separate structure, dfl_feature_dev_data, which lifetime is independent of the feature device, proceed to completely destroy and recreate the feature platform device on port release and assign, respectively. This resolves a longstanding issue in the use of platform_device_add(), which states to "not call this routine more than once for any device structure" and which used to print a kernel warning. The function feature_dev_unregister() resets the device pointer in the feature data to NULL to signal that the feature platform device has been destroyed. This substitutes the previous device_is_registered() checks. Signed-off-by: Xu Yilun Signed-off-by: Russ Weight Signed-off-by: Peter Colberg Reviewed-by: Matthew Gerlach Reviewed-by: Basheer Ahmed Muddebihal Acked-by: Xu Yilun Link: https://lore.kernel.org/r/20241120011035.230574-19-peter.colberg@intel.com Signed-off-by: Xu Yilun

fpga: dfl: drop unneeded get_device() and put_device() of feature device

2024-12-18T14:28:48+00:00

The feature device data was originally stored as platform data, hence the memory allocation was tied to the lifetime of the feature device. Now that the feature device data is tied to the lifetime of the DFL PCIe FPGA device instead, get_device() and put_device() are no longer needed. Signed-off-by: Peter Colberg Reviewed-by: Matthew Gerlach Reviewed-by: Basheer Ahmed Muddebihal Acked-by: Xu Yilun Link: https://lore.kernel.org/r/20241120011035.230574-18-peter.colberg@intel.com Signed-off-by: Xu Yilun

fpga: dfl: remove unneeded function build_info_create_dev()

2024-12-18T14:28:48+00:00

Remove the function build_info_create_dev(), which no longer serves its original purpose now that the allocation of the platform device has been moved to feature_dev_register(). Signed-off-by: Peter Colberg Reviewed-by: Matthew Gerlach Reviewed-by: Basheer Ahmed Muddebihal Acked-by: Xu Yilun Link: https://lore.kernel.org/r/20241120011035.230574-17-peter.colberg@intel.com Signed-off-by: Xu Yilun

fpga: dfl: allocate platform device after feature device data

2024-12-18T14:28:48+00:00

Delay calling platform_device_alloc() from build_info_create_dev() to feature_dev_register(), now that the feature device data contains all necessary data to create the feature device. This completes the new function feature_dev_register(), which will be reused in a subsequent commit to fully recreate the feature device when assigning a port. In the function feature_dev_unregister(), reset the device pointer in the feature data to NULL to signal that the platform device has been destroyed. This will substitute device_is_registered() in a subsequent commit. Reset the device pointer of each sub feature for consistency. Convert is_feature_dev_detected() to check whether binfo->type is not DFL_ID_MAX for deciding whether a feature device was detected during feature parsing, instead of checking binfo->feature_dev for non-NULL. Signed-off-by: Peter Colberg Reviewed-by: Matthew Gerlach Reviewed-by: Basheer Ahmed Muddebihal Acked-by: Xu Yilun Link: https://lore.kernel.org/r/20241120011035.230574-16-peter.colberg@intel.com Signed-off-by: Xu Yilun

fpga: dfl: store platform device id in feature device data

2024-12-18T14:28:48+00:00

Delay the feature device id allocation from build_info_create_dev() to binfo_create_feature_dev_data() and store the id in the feature device data before copying it to the device. This will allow reusing the same id in a subsequent commit which completely destroys and recreates the feature device when releasing and reassigning the corresponding port. Instead of manually freeing the id when no longer needed, use a device-managed resource with a custom action to automatically free the id right before the feature device data is freed. The id registry is guaranteed to be allocated when dfl_id_free_action() is invoked, since the DFL PCIe device and its device-managed resources will be destroyed before dfl_ids_destroy() is called in dfl_fpga_exit(). Signed-off-by: Peter Colberg Reviewed-by: Matthew Gerlach Reviewed-by: Basheer Ahmed Muddebihal Acked-by: Xu Yilun Link: https://lore.kernel.org/r/20241120011035.230574-15-peter.colberg@intel.com Signed-off-by: Xu Yilun

fpga: dfl: store platform device name in feature device data

2024-12-18T14:28:48+00:00

Add a new member, pdev_name, to the structure dfl_feature_dev_data that holds the platform device name for convenience. A subsequent commit will completely destroy the platform device during port release, after which fdata->dev is unavailable, while fdata itself remains available. Signed-off-by: Peter Colberg Reviewed-by: Matthew Gerlach Reviewed-by: Basheer Ahmed Muddebihal Acked-by: Xu Yilun Link: https://lore.kernel.org/r/20241120011035.230574-14-peter.colberg@intel.com Signed-off-by: Xu Yilun

fpga: dfl: store MMIO resources in feature device data

2024-12-18T14:28:48+00:00

Instead of directly copying the MMIO resource of each feature to the feature device resources, add a new member to the feature device data to store the resources and copy them to the feature device using platform_device_add_resources(). This prepares a subsequent commit which completely destroys and recreates the feature device when releasing and reassigning the corresponding port, respectively. Signed-off-by: Peter Colberg Reviewed-by: Matthew Gerlach Reviewed-by: Basheer Ahmed Muddebihal Acked-by: Xu Yilun Link: https://lore.kernel.org/r/20241120011035.230574-13-peter.colberg@intel.com Signed-off-by: Xu Yilun

fpga: dfl: convert features from flexible array member to separate array

2024-12-18T14:28:48+00:00

Use a separate array allocation for features and substitute a pointer for the flexible array member in the feature device data. A subsequent commit will add another array for resources. The current commit converts the flexible array member to a separate allocation for consistency. Signed-off-by: Peter Colberg Reviewed-by: Matthew Gerlach Reviewed-by: Basheer Ahmed Muddebihal Acked-by: Xu Yilun Link: https://lore.kernel.org/r/20241120011035.230574-12-peter.colberg@intel.com Signed-off-by: Xu Yilun

fpga: dfl: factor out feature device data from platform device data

2024-12-18T14:28:48+00:00

Add a structure dfl_feature_dev_data to hold the DFL enumeration info previously held in dfl_feature_platform_data. Allocate the new structure using device-managed memory whose lifetime is bound to the lifetime of the physical DFL, e.g., PCIe FPGA device. In a subsequent commit, this will allow the feature platform device to be completely destroyed and recreated on port release and assign, respectively, while retaining the feature data in the new dfl_feature_dev_data structure. Signed-off-by: Peter Colberg Reviewed-by: Matthew Gerlach Reviewed-by: Basheer Ahmed Muddebihal Acked-by: Xu Yilun Link: https://lore.kernel.org/r/20241120011035.230574-11-peter.colberg@intel.com Signed-off-by: Xu Yilun