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

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 <peter.colberg@intel.com>
Reviewed-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Reviewed-by: Basheer Ahmed Muddebihal <basheer.ahmed.muddebihal@linux.intel.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20241120011035.230574-15-peter.colberg@intel.com
Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
index cbff5d543c44..2e38c42b3920 100644
--- a/drivers/fpga/dfl.h
+++ b/drivers/fpga/dfl.h
@@ -309,6 +309,7 @@ struct dfl_feature {
  * @lock: mutex to protect feature dev data.
  * @dev: ptr to the feature's platform device linked with this structure.
  * @type: type of DFL FIU for the feature dev. See enum dfl_id_type.
+ * @pdev_id: platform device id for the feature dev.
  * @pdev_name: platform device name for the feature dev.
  * @dfl_cdev: ptr to container device.
  * @id: id used for the feature device.
@@ -326,6 +327,7 @@ struct dfl_feature_dev_data {
 	struct mutex lock;
 	struct platform_device *dev;
 	enum dfl_id_type type;
+	int pdev_id;
 	const char *pdev_name;
 	struct dfl_fpga_cdev *dfl_cdev;
 	int id;