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Date:   Tue, 21 Jul 2020 09:31:52 -0700
From:   Ira Weiny <ira.weiny@intel.com>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Andy Lutomirski <luto@kernel.org>, x86@kernel.org,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Vishal Verma <vishal.l.verma@intel.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Fenghua Yu <fenghua.yu@intel.com>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org,
        linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
        linux-kselftest@vger.kernel.org
Subject: Re: [PATCH RFC V2 13/17] kmap: Add stray write protection for device
 pages
Message-ID: <20200721163151.GA643353@iweiny-DESK2.sc.intel.com>
References: <20200717072056.73134-1-ira.weiny@intel.com>
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 <20200717092139.GC10769@hirez.programming.kicks-ass.net>
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On Mon, Jul 20, 2020 at 11:17:40AM +0200, Peter Zijlstra wrote:
> On Sat, Jul 18, 2020 at 09:13:19PM -0700, Ira Weiny wrote:
> > On Fri, Jul 17, 2020 at 11:21:39AM +0200, Peter Zijlstra wrote:
> > > On Fri, Jul 17, 2020 at 12:20:52AM -0700, ira.weiny@intel.com wrote:
> > > > @@ -31,6 +32,20 @@ static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
> > > >  
> > > >  #include <asm/kmap_types.h>
> > > >  
> > > > +static inline void enable_access(struct page *page)
> > > > +{
> > > > +	if (!page_is_access_protected(page))
> > > > +		return;
> > > > +	dev_access_enable();
> > > > +}
> > > > +
> > > > +static inline void disable_access(struct page *page)
> > > > +{
> > > > +	if (!page_is_access_protected(page))
> > > > +		return;
> > > > +	dev_access_disable();
> > > > +}
> > > 
> > > These are some very generic names, do we want them to be a little more
> > > specific?
> > 
> > I had them named kmap_* but Dave (I think it was Dave) thought they did not
> > really apply strictly to kmap_*.
> > 
> > They are static to this file which I thought may be sufficient to 'uniqify'
> > them?
> 
> They're static to a .h, which means they're all over the place ;-)

I've thought about it a bit.  I think I agree with both you and Dave.

How about:

dev_page_{en,dis}able_access()

??

I've made that change for now.

Thanks,
Ira