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Message-ID: <1776b49b-3c0e-41a7-bbc5-19310c428429@redhat.com>
Date: Tue, 9 Apr 2024 17:13:01 +0200
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Subject: Re: [PATCH v1 03/31] x86/resctrl: Move ctrlval string parsing policy
 away from the arch code
To: James Morse <james.morse@arm.com>, x86@kernel.org,
 linux-kernel@vger.kernel.org
Cc: Fenghua Yu <fenghua.yu@intel.com>,
 Reinette Chatre <reinette.chatre@intel.com>,
 Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
 Borislav Petkov <bp@alien8.de>, H Peter Anvin <hpa@zytor.com>,
 Babu Moger <Babu.Moger@amd.com>, shameerali.kolothum.thodi@huawei.com,
 D Scott Phillips OS <scott@os.amperecomputing.com>,
 carl@os.amperecomputing.com, lcherian@marvell.com,
 bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com,
 baolin.wang@linux.alibaba.com, Jamie Iles <quic_jiles@quicinc.com>,
 Xin Hao <xhao@linux.alibaba.com>, peternewman@google.com,
 dfustini@baylibre.com, amitsinght@marvell.com,
 Rex Nie <rex.nie@jaguarmicro.com>, Dave Martin <dave.martin@arm.com>
References: <20240321165106.31602-1-james.morse@arm.com>
 <20240321165106.31602-4-james.morse@arm.com>
From: David Hildenbrand <david@redhat.com>
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Organization: Red Hat
In-Reply-To: <20240321165106.31602-4-james.morse@arm.com>
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>   /*
>    * Check whether MBA bandwidth percentage value is correct. The value is
>    * checked against the minimum and max bandwidth values specified by the
> @@ -59,8 +68,8 @@ static bool bw_validate(char *buf, unsigned long *data, struct rdt_resource *r)
>   	return true;
>   }
>   
> -int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s,
> -	     struct rdt_domain *d)
> +static int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s,
> +		    struct rdt_domain *d)
>   {
>   	struct resctrl_staged_config *cfg;
>   	u32 closid = data->rdtgrp->closid;
> @@ -138,8 +147,8 @@ static bool cbm_validate(char *buf, u32 *data, struct rdt_resource *r)
>    * Read one cache bit mask (hex). Check that it is valid for the current
>    * resource type.
>    */
> -int parse_cbm(struct rdt_parse_data *data, struct resctrl_schema *s,
> -	      struct rdt_domain *d)
> +static int parse_cbm(struct rdt_parse_data *data, struct resctrl_schema *s,
> +		     struct rdt_domain *d)
>   {
>   	struct rdtgroup *rdtgrp = data->rdtgrp;
>   	struct resctrl_staged_config *cfg;
> @@ -195,6 +204,14 @@ int parse_cbm(struct rdt_parse_data *data, struct resctrl_schema *s,
>   	return 0;
>   }
>   
> +static ctrlval_parser_t *get_parser(struct rdt_resource *res)
> +{
> +	if (res->fflags & RFTYPE_RES_CACHE)
> +		return &parse_cbm;
> +	else
> +		return &parse_bw;
> +}

Besides what Reinette said, I'd have added here something that would 
fire in case someone adds something unexpected in the future, like

WARN_ON_ONCE(!(res->fflags & (RFTYPE_RES_CACHE|RFTYPE_RES_MB));

At the beginning of the function.


Apart from that, nothing jumped at me.

-- 
Cheers,

David / dhildenb