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 for <linuxppc-dev@lists.ozlabs.org> from <vaibhav@linux.vnet.ibm.com>;
 Wed, 20 Dec 2017 06:31:30 -0000
From: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
To: Christophe Lombard <clombard@linux.vnet.ibm.com>,
 linuxppc-dev@lists.ozlabs.org, fbarrat@linux.vnet.ibm.com,
 andrew.donnellan@au1.ibm.com
Subject: Re: [PATCH V4] cxl: Add support for ASB_Notify on POWER9
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Date: Wed, 20 Dec 2017 12:01:25 +0530
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Hi Christophe,

Thanks for the changes to the patch. Few minor review comments:

Christophe Lombard <clombard@linux.vnet.ibm.com> writes:

> @@ -362,3 +363,17 @@ void cxl_context_mm_count_put(struct cxl_context *ctx)
>  	if (ctx->mm)
>  		mmdrop(ctx->mm);
>  }
> +
> +int cxl_context_thread_tidr(struct cxl_context *ctx)
> +{
> +	int rc = 0;
> +
> +	if (!cxl_is_power9())
> +		return -ENODEV;
EINVAL might be a better return value instead of ENODEV in this case.

> --- a/drivers/misc/cxl/file.c
> +++ b/drivers/misc/cxl/file.c
> @@ -248,6 +248,13 @@ static long afu_ioctl_start_work(struct cxl_context *ctx,
>  	 */
>  	smp_mb();
>
> +	/* Assign a unique TIDR (thread id) for the current thread */
> +	if (work.flags & CXL_START_WORK_TID) {
> +		rc = cxl_context_thread_tidr(ctx);
> +		if (rc)
> +			goto out;
May need to copy the cxl_ioctl_start_work struct back to userspace with
the value of tidr allocated.

> +	}
> +
>  	trace_cxl_attach(ctx, work.work_element_descriptor,
> work.num_interrupts, amr);
should update the tracing here to also report the tidr

> diff --git a/include/uapi/misc/cxl.h b/include/uapi/misc/cxl.h
> index 49e8fd0..980ee8f 100644
> --- a/include/uapi/misc/cxl.h
> +++ b/include/uapi/misc/cxl.h
> @@ -31,9 +31,11 @@ struct cxl_ioctl_start_work {
Should reserve a field in the cxl_ioctl_start_work struct to report the
tidr back to userspace.


-- 
Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Linux Technology Center, IBM India Pvt. Ltd.