Re: [PATCH 2/6] device/pci: add cmdmem cap to pci_dev

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Mar 30, 2020 at 02:27:00PM -0700, Dave Jiang wrote:
> Since the current accelerator devices do not have standard PCIe capability
> enumeration for accepting ENQCMDS yet, for now an attribute of pdev->cmdmem has
> been added to struct pci_dev.  Currently a PCI quirk must be used for the
> devices that have such cap until the PCI cap is standardized. Add a helper
> function to provide the check if a device supports the cmdmem capability.
> 
> Such capability is expected to be added to PCIe device cap enumeration in
> the future.
> 
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  drivers/base/core.c    |   13 +++++++++++++
>  include/linux/device.h |    2 ++
>  include/linux/pci.h    |    1 +
>  3 files changed, 16 insertions(+)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index dbb0f9130f42..cd9f5b040ed4 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -27,6 +27,7 @@
>  #include <linux/netdevice.h>
>  #include <linux/sched/signal.h>
>  #include <linux/sysfs.h>
> +#include <linux/pci.h>
>  
>  #include "base.h"
>  #include "power/power.h"
> @@ -3790,3 +3791,15 @@ int device_match_any(struct device *dev, const void *unused)
>  	return 1;
>  }
>  EXPORT_SYMBOL_GPL(device_match_any);
> +
> +bool device_supports_cmdmem(struct device *dev)
> +{
> +	struct pci_dev *pdev;
> +
> +	if (!dev_is_pci(dev))
> +		return false;
> +
> +	pdev = to_pci_dev(dev);
> +	return pdev->cmdmem;
> +}
> +EXPORT_SYMBOL_GPL(device_supports_cmdmem);

Why would a pci-specific function like this be ok to have in the driver
core?  Please keep it in the pci core code instead.

thanks,

greg k-h