Re: [PATCH 5/5] ocxl: Provide additional metadata to userspace

["Alastair D'Silva" <alastair@au1.ibm.com>]

On Tue, 2019-09-17 at 11:43 +1000, Alastair D'Silva wrote:
> From: Alastair D'Silva <alastair@d-silva.org>
> 
> This patch exposes the OpenCAPI device serial number to
> userspace.
> 
> It also includes placeholders for the LPC & special purpose
> memory information (which will be populated in a subsequent patch)
> to avoid creating excessive versions of the IOCTL.
> 

I think it makes more sense to fold in the population of LPC & special
purpose memory into this patch, I'll address this in the next spin.

> Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
> ---
>  drivers/misc/ocxl/config.c | 46
> ++++++++++++++++++++++++++++++++++++++
>  drivers/misc/ocxl/file.c   |  3 ++-
>  include/misc/ocxl.h        |  1 +
>  include/uapi/misc/ocxl.h   |  9 +++++++-
>  4 files changed, 57 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c
> index fb0c3b6f8312..a9203c309365 100644
> --- a/drivers/misc/ocxl/config.c
> +++ b/drivers/misc/ocxl/config.c
> @@ -71,6 +71,51 @@ static int find_dvsec_afu_ctrl(struct pci_dev
> *dev, u8 afu_idx)
>  	return 0;
>  }
>  
> +/**
> + * Find a related PCI device (function 0)
> + * @device: PCI device to match
> + *
> + * Returns a pointer to the related device, or null if not found
> + */
> +static struct pci_dev *get_function_0(struct pci_dev *dev)
> +{
> +	unsigned int devfn = PCI_DEVFN(PCI_SLOT(dev->devfn), 0); //
> Look for function 0
> +
> +	return pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
> +					dev->bus->number, devfn);
> +}
> +
> +static void read_serial(struct pci_dev *dev, struct ocxl_fn_config
> *fn)
> +{
> +	u32 low, high;
> +	int pos;
> +
> +	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DSN);
> +	if (pos) {
> +		pci_read_config_dword(dev, pos + 0x04, &low);
> +		pci_read_config_dword(dev, pos + 0x08, &high);
> +
> +		fn->serial = low | ((u64)high) << 32;
> +
> +		return;
> +	}
> +
> +	if (PCI_FUNC(dev->devfn) != 0) {
> +		struct pci_dev *related = get_function_0(dev);
> +
> +		if (!related) {
> +			fn->serial = 0;
> +			return;
> +		}
> +
> +		read_serial(related, fn);
> +		pci_dev_put(related);
> +		return;
> +	}
> +
> +	fn->serial = 0;
> +}
> +
>  static void read_pasid(struct pci_dev *dev, struct ocxl_fn_config
> *fn)
>  {
>  	u16 val;
> @@ -208,6 +253,7 @@ int ocxl_config_read_function(struct pci_dev
> *dev, struct ocxl_fn_config *fn)
>  	int rc;
>  
>  	read_pasid(dev, fn);
> +	read_serial(dev, fn);
>  
>  	rc = read_dvsec_tl(dev, fn);
>  	if (rc) {
> diff --git a/drivers/misc/ocxl/file.c b/drivers/misc/ocxl/file.c
> index 2870c25da166..08f6f594a11d 100644
> --- a/drivers/misc/ocxl/file.c
> +++ b/drivers/misc/ocxl/file.c
> @@ -98,13 +98,14 @@ static long afu_ioctl_get_metadata(struct
> ocxl_context *ctx,
>  
>  	memset(&arg, 0, sizeof(arg));
>  
> -	arg.version = 0;
> +	arg.version = 1;
>  
>  	arg.afu_version_major = ctx->afu->config.version_major;
>  	arg.afu_version_minor = ctx->afu->config.version_minor;
>  	arg.pasid = ctx->pasid;
>  	arg.pp_mmio_size = ctx->afu->config.pp_mmio_stride;
>  	arg.global_mmio_size = ctx->afu->config.global_mmio_size;
> +	arg.serial = ctx->afu->fn->config.serial;
>  
>  	if (copy_to_user(uarg, &arg, sizeof(arg)))
>  		return -EFAULT;
> diff --git a/include/misc/ocxl.h b/include/misc/ocxl.h
> index a1897737908d..da75db149e6c 100644
> --- a/include/misc/ocxl.h
> +++ b/include/misc/ocxl.h
> @@ -46,6 +46,7 @@ struct ocxl_fn_config {
>  	int dvsec_afu_info_pos; /* offset of the AFU information DVSEC
> */
>  	s8 max_pasid_log;
>  	s8 max_afu_index;
> +	u64 serial;
>  };
>  
>  enum ocxl_endian {
> diff --git a/include/uapi/misc/ocxl.h b/include/uapi/misc/ocxl.h
> index 6d29a60a896a..d4c6bf10580c 100644
> --- a/include/uapi/misc/ocxl.h
> +++ b/include/uapi/misc/ocxl.h
> @@ -45,7 +45,14 @@ struct ocxl_ioctl_metadata {
>  
>  	/* End version 0 fields */
>  
> -	__u64 reserved[13]; /* Total of 16*u64 */
> +	// Version 1 fields
> +	__u64 lpc_mem_size;
> +	__u64 special_purpose_mem_size;
> +	__u64 serial;		// Device serial number
> +
> +	// End version 1 fields
> +
> +	__u64 reserved[10]; // Total of 16*u64
>  };
>  
>  struct ocxl_ioctl_p9_wait {
> -- 
> 2.21.0

-- 
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819