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.
Signed-off-by: Li, Zhen-Hua <[email protected]> --- drivers/iommu/intel-iommu.c | 88 +++++++++++++++---------------------------- 1 file changed, 31 insertions(+), 57 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index b4f0e28..ae10471 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -221,55 +221,28 @@ 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); -} -static inline void context_set_present(struct context_entry *context) -{ - context->lo |= 1; -} - -static inline void context_set_fault_enable(struct context_entry *context) -{ - context->lo &= (((u64)-1) << 2) | 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; -} - -static inline void context_set_address_root(struct context_entry *context, - unsigned long value) -{ - context->lo |= value & VTD_PAGE_MASK; -} - -static inline void context_set_address_width(struct context_entry *context, - unsigned long value) -{ - context->hi |= value & 7; -} - -static inline void context_set_domain_id(struct context_entry *context, - unsigned long value) -{ - context->hi |= (value & ((1 << 16) - 1)) << 8; -} - -static inline void context_clear_entry(struct context_entry *context) -{ - context->lo = 0; - context->hi = 0; -} - /* * 0: readable * 1: writable @@ -727,7 +700,7 @@ static int device_context_mapped(struct intel_iommu *iommu, u8 bus, u8 devfn) ret = 0; goto out; } - ret = context_present(&context[devfn]); + ret = context->present; out: spin_unlock_irqrestore(&iommu->lock, flags); return ret; @@ -743,7 +716,8 @@ static void clear_context_table(struct intel_iommu *iommu, u8 bus, u8 devfn) root = &iommu->root_entry[bus]; context = get_context_addr_from_root(root); if (context) { - context_clear_entry(&context[devfn]); + context[devfn].lo = 0; + context[devfn].hi = 0; __iommu_flush_cache(iommu, &context[devfn], \ sizeof(*context)); } @@ -1573,7 +1547,7 @@ static int domain_context_mapping_one(struct dmar_domain *domain, int segment, if (!context) return -ENOMEM; spin_lock_irqsave(&iommu->lock, flags); - if (context_present(context)) { + if (context->present) { spin_unlock_irqrestore(&iommu->lock, flags); return 0; } @@ -1623,7 +1597,7 @@ static int domain_context_mapping_one(struct dmar_domain *domain, int segment, } } - context_set_domain_id(context, id); + context->did = id; if (translation != CONTEXT_TT_PASS_THROUGH) { info = iommu_support_dev_iotlb(domain, segment, bus, devfn); @@ -1635,15 +1609,15 @@ static int domain_context_mapping_one(struct dmar_domain *domain, int segment, * AGAW value supported by hardware. And ASR is ignored by hardware. */ if (unlikely(translation == CONTEXT_TT_PASS_THROUGH)) - context_set_address_width(context, iommu->msagaw); + context->aw = iommu->msagaw; else { - context_set_address_root(context, virt_to_phys(pgd)); - context_set_address_width(context, iommu->agaw); + context->asr = virt_to_phys(pgd) >> VTD_PAGE_SHIFT; + context->aw = iommu->agaw; } - context_set_translation_type(context, translation); - context_set_fault_enable(context); - context_set_present(context); + context->translation_type = translation; + context->fpd = 0; + context->present = 1; domain_flush_cache(domain, context, sizeof(*context)); /* -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
