Re: [PATCH] cxl: Add cxl_read_adapter_vpd() to the kernel API

[Michael Neuling <michael.neuling@au.ibm.com>]

On Tue, 2016-01-19 at 18:14 +0100, Frederic Barrat wrote:
> Introduce a new API to read the VPD of the adapter. In bare-metal, a
> kernel driver can find out the adapter pci_dev behind the AFU device
> and call pci_read_vpd() directly, but it won't work in a (powerVM)
> guest.
> Current implementation is a stub to allow existing drivers (cxlflash)
> to start using it.

This looks good.

The only thing I'm a bit concerned about is are we going to end up
duplicating a lot of the linux PCI API, but I guess we are only going
to do this for things the papr HCALL interface mimics.

Mikey

> Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
> ---
>  drivers/misc/cxl/api.c | 8 ++++++++
>  include/misc/cxl.h     | 5 +++++
>  2 files changed, 13 insertions(+)
>=20
> diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c
> index ea3eeb7..c73aa3a 100644
> --- a/drivers/misc/cxl/api.c
> +++ b/drivers/misc/cxl/api.c
> @@ -363,3 +363,11 @@ void cxl_perst_reloads_same_image(struct cxl_afu
> *afu,
>  	afu->adapter->perst_same_image =3D perst_reloads_same_image;
>  }
>  EXPORT_SYMBOL_GPL(cxl_perst_reloads_same_image);
> +
> +ssize_t cxl_read_adapter_vpd(struct pci_dev *afu_dev, void *buf,
> size_t count)
> +{
> +	struct device *parent =3D cxl_get_phys_dev(afu_dev);
> +
> +	return pci_read_vpd(to_pci_dev(parent), 0, count, buf);
> +}
> +EXPORT_SYMBOL_GPL(cxl_read_adapter_vpd);
> diff --git a/include/misc/cxl.h b/include/misc/cxl.h
> index f2ffe5b..3f9e84f 100644
> --- a/include/misc/cxl.h
> +++ b/include/misc/cxl.h
> @@ -210,4 +210,9 @@ ssize_t cxl_fd_read(struct file *file, char
> __user *buf, size_t count,
>  void cxl_perst_reloads_same_image(struct cxl_afu *afu,
>  				  bool perst_reloads_same_image);
> =20
> +/*
> + * Read the VPD of the adapter where the AFU pci dev resides
> + */
> +ssize_t cxl_read_adapter_vpd(struct pci_dev *afu_dev, void *buf,
> size_t count);
> +
>  #endif /* _MISC_CXL_H */