Just curious, why would |= operation cause problem? :)
On Fri, Dec 20, 2013 at 4:45 PM, Li, Zhen-Hua <[email protected]> wrote: > There is a structure named context_entry used by intel iommu, and there > are some bit operations on it. Use bit structure may make these operations > easy. > Also the function context_set_address_root may cause problem because it > uses > |= operation, not set the new value. And this patch can fix it. > > Signed-off-by: Li, Zhen-Hua <[email protected]> > --- > drivers/iommu/intel-iommu.c | 37 +++++++++++++++++++++++++++---------- > 1 file changed, 27 insertions(+), 10 deletions(-) > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > index 43b9bfe..65cd480 100644 > --- a/drivers/iommu/intel-iommu.c > +++ b/drivers/iommu/intel-iommu.c > @@ -221,47 +221,64 @@ get_context_addr_from_root(struct root_entry *root) > * 8-23: domain id > */ > struct context_entry { > - u64 lo; > - u64 hi; > + union { > + struct { > + u64 present:1, > + fpd:1, > + translation_type:2, > + reserved_l:8, > + asr:52; > + }; > + u64 lo; > + }; > + union { > + struct { > + u64 aw:3, > + avail:4, > + reserved_h1:1, > + did:16, > + reserved_h2:40; > + }; > + u64 hi; > + }; > }; > > static inline bool context_present(struct context_entry *context) > { > - return (context->lo & 1); > + return context->present; > } > static inline void context_set_present(struct context_entry *context) > { > - context->lo |= 1; > + context->present = 1; > } > > static inline void context_set_fault_enable(struct context_entry *context) > { > - context->lo &= (((u64)-1) << 2) | 1; > + context->fpd = 1; > } > > static inline void context_set_translation_type(struct context_entry > *context, > unsigned long value) > { > - context->lo &= (((u64)-1) << 4) | 3; > - context->lo |= (value & 3) << 2; > + context->translation_type = value; > } > > static inline void context_set_address_root(struct context_entry *context, > unsigned long value) > { > - context->lo |= value & VTD_PAGE_MASK; > + context->asr = value >> VTD_PAGE_SHIFT > } > > static inline void context_set_address_width(struct context_entry > *context, > unsigned long value) > { > - context->hi |= value & 7; > + context->aw = value; > } > > static inline void context_set_domain_id(struct context_entry *context, > unsigned long value) > { > - context->hi |= (value & ((1 << 16) - 1)) << 8; > + context->did = value; > } > > static inline void context_clear_entry(struct context_entry *context) > -- > 1.8.4.3 > > _______________________________________________ > iommu mailing list > [email protected] > https://lists.linuxfoundation.org/mailman/listinfo/iommu >
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