From: will.deacon@arm•com (Will Deacon)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM: tlb: __flush_tlb_mm need to use int asid var for BE correct operation
Date: Mon, 7 Oct 2013 11:49:36 +0100 [thread overview]
Message-ID: <20131007104936.GG465@mudshark.cambridge.arm.com> (raw)
In-Reply-To: <20131007104524.GK12758@n2100.arm.linux.org.uk>
On Mon, Oct 07, 2013 at 11:45:24AM +0100, Russell King - ARM Linux wrote:
> On Sun, Oct 06, 2013 at 11:47:38PM -0700, Victor Kamensky wrote:
> > __flush_tlb_mm function need to use intermediate 'int' type 'asid'
> > variable int tlb_op macro call. Direct use of ASID macro produces
> > 64 bit unsigned long long type passed to inline assembler statement
> > as 'r' operand (32bit), and resulting behavior is not well specified.
> > It works in little endian case, but is broken in big endian case. In
> > big endian case gcc generate such code that 0 is passed to
> > 'mcr 15, 0, r4, cr8, cr3, {2}' operation.
> >
> > Note other functions like __local_flush_tlb_mm, and local_flush_tlb_mm
> > already use intermediate 'asid' variable in similar code.
>
> A much better solution would be to ensure that ASID() only returns
> the 'unsigned' type, not a long long type.
>
> #define ASID(mm) ((unsigned)(mm)->context.id.counter & ~ASID_MASK)
Yup, that looks good to me. This is similar to the problem Ben already fixed
in the mmid macro, so I think this should be included as part of his BE
series.
Speaking of which -- it's probably a good time to refresh and repost that if
we're aiming for 3.13...
Will
next prev parent reply other threads:[~2013-10-07 10:49 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-07 6:47 [PATCH] ARM: tlb: __flush_tlb_mm need to use int asid var for BE correct operation Victor Kamensky
2013-10-07 6:47 ` Victor Kamensky
2013-10-07 10:32 ` Ben Dooks
2013-10-07 10:33 ` Ben Dooks
2013-10-07 10:45 ` Russell King - ARM Linux
2013-10-07 10:49 ` Will Deacon [this message]
2013-10-07 10:55 ` Ben Dooks
2013-10-07 13:15 ` Thomas Petazzoni
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