Subject: Re: linux-next: Tree for November 5

From: Bjorn Helgaas <[email-masked]>
Date: Fri, 6 Nov 2009 09:56:08 -0600

On Thursday 05 November 2009 10:17:11 am Bjorn Helgaas wrote:
> On Thursday 05 November 2009 09:31:04 am Bjorn Helgaas wrote:
> > On Thursday 05 November 2009 03:38:27 am Sachin Sant wrote:
> > > Today's next tree fails to build on i386 with
> > > 
> > > arch/x86/pci/built-in.o: In function `align_resource':
> > > arch/x86/pci/acpi.c:82: undefined reference to `__udivdi3'
> > > 
> > > The code in question was added by commit
> > > 03db42adfeeabe856dbb6894dd3aaff55838330a.
> > 
> > I'll look into this.  I did build and test a 32-bit x86 kernel, but
> > I built it on an x86_64 box using "linux32 make ...", which looks like
> > it used gcc 4.3.2.
> 
> Can you try the patch below, please?

Sachin, can you please try this patch and report whether it
fixes the undefined reference?  I hate to have linux-next
broken longer than necessary.

> commit 00f16f0a2f4826eadec0565e4b454ab8bc7824cc
> Author: Bjorn Helgaas <[email-masked]>
> Date:   Thu Nov 5 10:03:57 2009 -0700
> 
>     x86/PCI: remove 64-bit division
>     
>     The roundup() caused a build error (undefined reference to `__udivdi3').
>     We're aligning to power-of-two boundaries, so it's simpler to just use
>     ALIGN() anyway, which avoids the division.
>     
>     Signed-off-by: Bjorn Helgaas <[email-masked]>
> 
> diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
> index 8ddf4f4..959e548 100644
> --- a/arch/x86/pci/acpi.c
> +++ b/arch/x86/pci/acpi.c
> @@ -69,17 +69,17 @@ align_resource(struct acpi_device *bridge, struct resource *res)
>  	 * that claim this address space have starting alignment and length
>  	 * constraints, so fix any obvious BIOS goofs.
>  	 */
> -	if (res->start & (align - 1)) {
> +	if (!IS_ALIGNED(res->start, align)) {
>  		dev_printk(KERN_DEBUG, &bridge->dev,
>  			   "host bridge window %pR invalid; "
>  			   "aligning start to %d-byte boundary\n", res, align);
>  		res->start &= ~(align - 1);
>  	}
> -	if ((res->end + 1) & (align - 1)) {
> +	if (!IS_ALIGNED(res->end + 1, align)) {
>  		dev_printk(KERN_DEBUG, &bridge->dev,
>  			   "host bridge window %pR invalid; "
>  			   "aligning end to %d-byte boundary\n", res, align);
> -		res->end = roundup(res->end, align) - 1;
> +		res->end = ALIGN(res->end, align) - 1;
>  	}
>  }
>  
>