Messages in this thread | | | Date | Tue, 9 Sep 2014 11:26:53 +0200 | From | Robert Richter <> | Subject | Re: [PATCH] GICv3: Fixing 32 bit compatibility |
| |
On 09.09.14 11:19:12, Uwe Kleine-König wrote: > On Tue, Sep 09, 2014 at 11:12:01AM +0200, Robert Richter wrote: > > On 09.09.14 10:00:42, Uwe Kleine-König wrote: > > > On Mon, Sep 08, 2014 at 04:11:19PM +0200, Robert Richter wrote: > > > > > > @@ -479,7 +479,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) > > > > smp_wmb(); > > > > > > > > for_each_cpu_mask(cpu, *mask) { > > > > - u64 cluster_id = cpu_logical_map(cpu) & ~0xffUL; > > > > + u64 cluster_id = cpu_logical_map(cpu) & ~0xffULL; > > > This doesn't change anything, does it? > > > > It does, not in 64 bit but in 32 bit there unsigned long is 32 > > bit. So, bit masks are broken if you compile a 32 bit kernel. > Can you make an example where the result actually changes?
Upper 32 bits will be cleared above.
> > > I wonder if it would be cleaner to use (u64)0xff here. > > > > No, that's ULL for. This is commonly used in x86 too. > I don't care much here, but I'd say ULL is to force an unsigned long > long. If you want to make it obvious that you want a 64bit value, a cast > to u64 makes this more clear.
ULL is no cast at all.
-Robert -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |