Re: [PATCH v2] crypto: caam/qi2 - Add printing dpseci fq stats using debugfs

From: Horia Geanta <horia.geanta@nxp.com>
To: Vakul Garg <vakul.garg@nxp.com>,
	"linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>
Cc: Aymen Sghaier <aymen.sghaier@nxp.com>,
	"herbert@gondor.apana.org.au" <herbert@gondor.apana.org.au>
Subject: Re: [PATCH v2] crypto: caam/qi2 - Add printing dpseci fq stats using debugfs
Date: Tue, 23 Jul 2019 06:14:43 +0000	[thread overview]
Message-ID: <VI1PR0402MB34854E7762F7A602F322003B98C70@VI1PR0402MB3485.eurprd04.prod.outlook.com> (raw)
In-Reply-To: DB7PR04MB46203BDE7B36E66FCD5D03D08BC70@DB7PR04MB4620.eurprd04.prod.outlook.com

On 7/23/2019 4:20 AM, Vakul Garg wrote:
>>> @@ -64,6 +65,7 @@ struct dpaa2_caam_priv {
>>>  	struct iommu_domain *domain;
>>>
>>>  	struct dpaa2_caam_priv_per_cpu __percpu *ppriv;
>>> +	struct dentry *dfs_root;
>> dfs_root is used only in dpseci-debugfs.c, let's have it there as global.
>>
> 
> I submitted this change in v3. There is still a minor issue with this patch version. 
> Before submitting the next v4, I have a question.
> 
> Could there be a situation that there are multiple  dpseci objects assigned to kernel?
In theory, yes.
fsl-mc, the bus dpseci devices sit on, allows for multiple instances.

However, caam/qi2 (driver for dpseci devices) doesn't have support
for this.
For e.g., all dpseci instances would try to register the algorithms using
the same name & driver name - something that will trigger an error
in crypto API.
This could be easily fixed, however the real issue is that
there is no load balancing support - neither at crypto API level
nor at driver level.

> In that case, we need to maintain dfs_root for each separately.
>  
Ok, let's keep dfs_root per device.
For now this has no practical value, but at least makes the work easier
in case load balancing support is added at some point.

Horia