[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <20080731151115.GB32173@elte.hu>
Date: Thu, 31 Jul 2008 17:11:15 +0200
From: Ingo Molnar <mingo@...e.hu>
To: Eduardo Habkost <ehabkost@...hat.com>
Cc: Jeremy Fitzhardinge <jeremy@...p.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] xen_alloc_ptpage: cast PFN_PHYS() argument to unsigned
long
* Eduardo Habkost <ehabkost@...hat.com> wrote:
> Currently paravirt_ops alloc_p*() uses u32 for the pfn args. We should
> change that later, but while the pfn parameter is still u32, we need
> to cast the PFN_PHYS() argument at xen_alloc_ptpage() to unsigned
> long, otherwise it will lose bits on the shift.
>
> I think PFN_PHYS() should behave better when fed with smaller
> integers, but a cast to unsigned long won't be enough for all cases on
> 32-bit PAE, and a cast to u64 would be overkill for most users of
> PFN_PHYS().
>
> We could have two different flavors of PFN_PHYS: one for low pages
> only (unsigned long) and another that works for any page (u64)), but
> while we don't have it, we will need the cast to unsigned long on
> xen_alloc_ptpage().
>
> Signed-off-by: Eduardo Habkost <ehabkost@...hat.com>
> Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@...rix.com>
applied to tip/x86/xen - thanks Eduardo.
Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists