Re: [RESEND v13 16/25] CXL/AER: Introduce pcie/aer_cxl_vh.c in AER driver for forwarding CXL errors

From: dan.j.williams

Date: Wed Nov 19 2025 - 19:54:10 EST


Terry Bowman wrote:
> CXL virtual hierarchy (VH) RAS handling for CXL Port devices will be added
> soon. This requires a notification mechanism for the AER driver to share
> the AER interrupt with the CXL driver. The notification will be used as an
> indication for the CXL drivers to handle and log the CXL RAS errors.
>
> Note, 'CXL protocol error' terminology will refer to CXL VH and not
> CXL RCH errors unless specifically noted going forward.
>
> Introduce a new file in the AER driver to handle the CXL protocol errors
> named pci/pcie/aer_cxl_vh.c.
>
> Add a kfifo work queue to be used by the AER and CXL drivers. The AER
> driver will be the sole kfifo producer adding work and the cxl_core will be
> the sole kfifo consumer removing work. Add the boilerplate kfifo support.
> Encapsulate the kfifo, RW semaphore, and work pointer in a single structure.
>
> Add CXL work queue handler registration functions in the AER driver. Export
> the functions allowing CXL driver to access. Implement registration
> functions for the CXL driver to assign or clear the work handler function.
> Synchronize accesses using the RW semaphore.
>
> Introduce 'struct cxl_proto_err_work_data' to serve as the kfifo work data.
> This will contain a reference to the erring PCI device and the error
> severity. This will be used when the work is dequeued by the cxl_core driver.
>
> Signed-off-by: Terry Bowman <terry.bowman@xxxxxxx>
> Reviewed-by: Jonathan Cameron <jonathan.cameron@xxxxxxxxxx>
> Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
[..]
> diff --git a/include/linux/aer.h b/include/linux/aer.h
> index 2ef820563996..6b2c87d1b5b6 100644
> --- a/include/linux/aer.h
> +++ b/include/linux/aer.h
> @@ -10,6 +10,7 @@
>
> #include <linux/errno.h>
> #include <linux/types.h>
> +#include <linux/workqueue_types.h>

This is minor, but nothing in this header needs anything from
linux/workqueue_types.h.

I would just forward declare and be done, i.e.:

struct work_struct;
void cxl_register_proto_err_work(struct work_struct *work);