From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH] xen/arm: ioremap_attr: return NULL is __vmap failed Date: Fri, 15 Nov 2013 15:45:20 +0000 Message-ID: <52864190.4000908@citrix.com> References: <1384529257-7590-1-git-send-email-julien.grall@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1VhLaH-0004rM-05 for xen-devel@lists.xenproject.org; Fri, 15 Nov 2013 15:45:25 +0000 In-Reply-To: <1384529257-7590-1-git-send-email-julien.grall@linaro.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Julien Grall Cc: xen-devel@lists.xenproject.org, patches@linaro.org, tim@xen.org, ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com List-Id: xen-devel@lists.xenproject.org On 15/11/13 15:27, Julien Grall wrote: > Most of ioremap_* caller check if ioremap returns NULL. Actually, if the > physical address is non-aligned, Xen will return the pointer given by > __vmap plus the offset in the page. So if ioremap_* fails, the caller > will retrieve an non-NULL address and continue as if there was no error. > > Signed-off-by: Julien Grall > --- > xen/arch/arm/mm.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c > index 26c6768..5137668 100644 > --- a/xen/arch/arm/mm.c > +++ b/xen/arch/arm/mm.c > @@ -742,8 +742,13 @@ void *ioremap_attr(paddr_t pa, size_t len, unsigned int attributes) > unsigned long pfn = PFN_DOWN(pa); > unsigned int offs = pa & (PAGE_SIZE - 1); > unsigned int nr = PFN_UP(offs + len); > + void *ptr; > > - return (__vmap(&pfn, nr, 1, 1, attributes) + offs); > + ptr = __vmap(&pfn, nr, 1, 1, attributes); No need to split the declaration of void *ptr and its initialisation. ~Andrew > + if ( ptr == NULL ) > + return NULL; > + > + return (ptr + offs); > } > > void *ioremap(paddr_t pa, size_t len)