Re: [PATCH v3 1/2] ocxl: Add get_metadata IOCTL to share OCXL information to userspace

[Frederic Barrat <fbarrat@linux.vnet.ibm.com>]

Le 22/02/2018 à 05:17, Alastair D'Silva a écrit :
> From: Alastair D'Silva <alastair@d-silva.org>
> 
> Some required information is not exposed to userspace currently (eg. the
> PASID), pass this information back, along with other information which
> is currently communicated via sysfs, which saves some parsing effort in
> userspace.
> 
> Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
> ---

Thanks!
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>


>   drivers/misc/ocxl/file.c | 27 +++++++++++++++++++++++++++
>   include/uapi/misc/ocxl.h | 17 +++++++++++++++++
>   2 files changed, 44 insertions(+)
> 
> diff --git a/drivers/misc/ocxl/file.c b/drivers/misc/ocxl/file.c
> index d9aa407db06a..90df1be5ef3f 100644
> --- a/drivers/misc/ocxl/file.c
> +++ b/drivers/misc/ocxl/file.c
> @@ -102,10 +102,32 @@ static long afu_ioctl_attach(struct ocxl_context *ctx,
>   	return rc;
>   }
> 
> +static long afu_ioctl_get_metadata(struct ocxl_context *ctx,
> +		struct ocxl_ioctl_metadata __user *uarg)
> +{
> +	struct ocxl_ioctl_metadata arg;
> +
> +	memset(&arg, 0, sizeof(arg));
> +
> +	arg.version = 0;
> +
> +	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;
> +
> +	if (copy_to_user(uarg, &arg, sizeof(arg)))
> +		return -EFAULT;
> +
> +	return 0;
> +}
> +
>   #define CMD_STR(x) (x == OCXL_IOCTL_ATTACH ? "ATTACH" :			\
>   			x == OCXL_IOCTL_IRQ_ALLOC ? "IRQ_ALLOC" :	\
>   			x == OCXL_IOCTL_IRQ_FREE ? "IRQ_FREE" :		\
>   			x == OCXL_IOCTL_IRQ_SET_FD ? "IRQ_SET_FD" :	\
> +			x == OCXL_IOCTL_GET_METADATA ? "GET_METADATA" :	\
>   			"UNKNOWN")
> 
>   static long afu_ioctl(struct file *file, unsigned int cmd,
> @@ -157,6 +179,11 @@ static long afu_ioctl(struct file *file, unsigned int cmd,
>   					irq_fd.eventfd);
>   		break;
> 
> +	case OCXL_IOCTL_GET_METADATA:
> +		rc = afu_ioctl_get_metadata(ctx,
> +				(struct ocxl_ioctl_metadata __user *) args);
> +		break;
> +
>   	default:
>   		rc = -EINVAL;
>   	}
> diff --git a/include/uapi/misc/ocxl.h b/include/uapi/misc/ocxl.h
> index 4b0b0b756f3e..0af83d80fb3e 100644
> --- a/include/uapi/misc/ocxl.h
> +++ b/include/uapi/misc/ocxl.h
> @@ -32,6 +32,22 @@ struct ocxl_ioctl_attach {
>   	__u64 reserved3;
>   };
> 
> +struct ocxl_ioctl_metadata {
> +	__u16 version; // struct version, always backwards compatible
> +
> +	// Version 0 fields
> +	__u8  afu_version_major;
> +	__u8  afu_version_minor;
> +	__u32 pasid;		// PASID assigned to the current context
> +
> +	__u64 pp_mmio_size;	// Per PASID MMIO size
> +	__u64 global_mmio_size;
> +
> +	// End version 0 fields
> +
> +	__u64 reserved[13]; // Total of 16*u64
> +};
> +
>   struct ocxl_ioctl_irq_fd {
>   	__u64 irq_offset;
>   	__s32 eventfd;
> @@ -45,5 +61,6 @@ struct ocxl_ioctl_irq_fd {
>   #define OCXL_IOCTL_IRQ_ALLOC	_IOR(OCXL_MAGIC, 0x11, __u64)
>   #define OCXL_IOCTL_IRQ_FREE	_IOW(OCXL_MAGIC, 0x12, __u64)
>   #define OCXL_IOCTL_IRQ_SET_FD	_IOW(OCXL_MAGIC, 0x13, struct ocxl_ioctl_irq_fd)
> +#define OCXL_IOCTL_GET_METADATA _IOR(OCXL_MAGIC, 0x14, struct ocxl_ioctl_metadata)
> 
>   #endif /* _UAPI_MISC_OCXL_H */
>