Re: [PATCH] testing/cxl: Fix abused pci_bus_read_config_word() on platform device

[Dan Williams]

Ira Weiny wrote:
[..]
> > --- a/drivers/cxl/core/cdat.c
> > +++ b/drivers/cxl/core/cdat.c
> > @@ -5,6 +5,7 @@
> >    #include <linux/fw_table.h>
> >    #include <linux/node.h>
> >    #include <linux/overflow.h>
> > +#include <linux/platform_device.h>
> >    #include "cxlpci.h"
> >    #include "cxlmem.h"
> >    #include "core.h"
> > @@ -641,9 +642,13 @@ static int cxl_endpoint_gather_bandwidth(struct cxl_region *cxlr,
> >           void *ptr;
> >           int rc;
> > 
> > +       if (dev_is_pci(cxlds->dev))
> 
> Did you mean...
> 
> 	if (!dev_is_pci(cxlds->dev))
> ???

Yes, skip non-PCI.

[..]
> Couldn't this be done on the endpoint call?  (Making it non-static?)
> 
> int __wrap_cxl_endpoint_gather_bandwidth(...
>                                          struct cxl_endpoint_decoder *cxled,
> 					...)
> {
>         struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
>         struct cxl_dev_state *cxlds = cxlmd->cxlds;
> 
> 	if (!dev_is_pci(cxlds->dev))
> 		return -ENODEV;
> 
> 	return cxl_endpoint_gather_bandwidth(...);
> }

No, cxl_endpoint_gather_bandwidth() is called internal to cxl_core,
there is no opportunity to optionally wrap it, only replace it.

In order for this path to be mocked the cxl_region driver would need to
be moved to a module and then
cxl_region_shared_upstream_bandwidth_update() could be unit tested.