Messages in this thread |  | | Date | Sun, 19 Jul 2015 08:27:24 -0700 | | From | Guenter Roeck <> | | Subject | Re: [PATCH] iommu-common: Do not use 64 bit constant 0xffffffffffffffffl for computing align_mask |
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On Sun, Jul 19, 2015 at 02:20:14PM +0200, Sowmini Varadhan wrote: > > Using a 64 bit constant generates "warning: integer constant is too > large for 'long' type" on 32 bit platforms. Instead use ~0l to get > the desired effect. > > Detected by Andrew Morton who has confirmed that this patch > fixes the warning on i386/gcc-4.4.3, i386/gcc-4.4.0 and arm/gcc-4.4.4. > > Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> > --- > lib/iommu-common.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/lib/iommu-common.c b/lib/iommu-common.c > index df30632..fd1297d 100644 > --- a/lib/iommu-common.c > +++ b/lib/iommu-common.c > @@ -119,7 +119,7 @@ unsigned long iommu_tbl_range_alloc(struct device *dev, > unsigned long align_mask = 0; > > if (align_order > 0) > - align_mask = 0xffffffffffffffffl >> (64 - align_order); > + align_mask = ~0l >> (64 - align_order); > Wonder if this just hides the real problem. Unless align_order is very large, the resulting mask on 32 bit systems may be 0. Is this really the idea ?
Guenter
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