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Date:   Sat, 20 Aug 2022 08:10:48 -0700
From:   Davidlohr Bueso <dave@stgolabs.net>
To:     Ira Weiny <ira.weiny@intel.com>
Cc:     linux-arch@vger.kernel.org, dan.j.williams@intel.com,
        peterz@infradead.org, mark.rutland@arm.com, dave.jiang@intel.com,
        Jonathan.Cameron@huawei.com, a.manzanares@samsung.com,
        bwidawsk@kernel.org, alison.schofield@intel.com,
        linux-cxl@vger.kernel.org, nvdimm@lists.linux.dev, x86@kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] arch/cacheflush: Introduce flush_all_caches()
Message-ID: <20220820151048.cfpkqhut5z6wa6yk@offworld>
References: <20220819171024.1766857-1-dave@stgolabs.net>
 <YwAo1Ec13hjiBOat@iweiny-desk3>
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On Fri, 19 Aug 2022, Ira Weiny wrote:

>Did you mean "must"?

Yep.

>> + * such as those which caches are in a consistent state. The
>> + * caller can verify the situation early on.
>> + */
>> +#ifndef flush_all_caches
>> +# define flush_all_caches_capable() false
>> +static inline void flush_all_caches(void)
>> +{
>> +	WARN_ON_ONCE("cache invalidation required\n");
>> +}
>
>With the addition of flush_all_caches_capable() will flush_all_caches() ever be
>called?

No, it should not. Hence you get a splat if you call it bogusly.