iommu/vt-d: Introduce helper domain_pfn_within_range() to simplify code

Introduce helper function domain_pfn_within_range() to simplify code
and improve readability.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 16 insertions, 14 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0852b7021e4a..c9e65edaa2ad 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -549,6 +549,14 @@ static inline int domain_type_is_vm_or_si(struct dmar_domain *domain)
                                 DOMAIN_FLAG_STATIC_IDENTITY);
 }
 
+static inline int domain_pfn_supported(struct dmar_domain *domain,
+                                       unsigned long pfn)
+{
+        int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
+
+        return !(addr_width < BITS_PER_LONG && pfn >> addr_width);
+}
+
 static int __iommu_calculate_agaw(struct intel_iommu *iommu, int max_gaw)
 {
         unsigned long sagaw;
@@ -822,14 +830,13 @@ out:
 static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
                                       unsigned long pfn, int *target_level)
 {
-        int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
         struct dma_pte *parent, *pte = NULL;
         int level = agaw_to_level(domain->agaw);
         int offset;
 
         BUG_ON(!domain->pgd);
 
-        if (addr_width < BITS_PER_LONG && pfn >> addr_width)
+        if (!domain_pfn_supported(domain, pfn))
                 /* Address beyond IOMMU's addressing capabilities. */
                 return NULL;
 
@@ -912,12 +919,11 @@ static void dma_pte_clear_range(struct dmar_domain *domain,
                                 unsigned long start_pfn,
                                 unsigned long last_pfn)
 {
-        int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
         unsigned int large_page = 1;
         struct dma_pte *first_pte, *pte;
 
-        BUG_ON(addr_width < BITS_PER_LONG && start_pfn >> addr_width);
-        BUG_ON(addr_width < BITS_PER_LONG && last_pfn >> addr_width);
+        BUG_ON(!domain_pfn_supported(domain, start_pfn));
+        BUG_ON(!domain_pfn_supported(domain, last_pfn));
         BUG_ON(start_pfn > last_pfn);
 
         /* we don't need lock here; nobody else touches the iova range */
@@ -978,10 +984,8 @@ static void dma_pte_free_pagetable(struct dmar_domain *domain,
                                    unsigned long start_pfn,
                                    unsigned long last_pfn)
 {
-        int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
-
-        BUG_ON(addr_width < BITS_PER_LONG && start_pfn >> addr_width);
-        BUG_ON(addr_width < BITS_PER_LONG && last_pfn >> addr_width);
+        BUG_ON(!domain_pfn_supported(domain, start_pfn));
+        BUG_ON(!domain_pfn_supported(domain, last_pfn));
         BUG_ON(start_pfn > last_pfn);
 
         dma_pte_clear_range(domain, start_pfn, last_pfn);
@@ -1083,11 +1087,10 @@ struct page *domain_unmap(struct dmar_domain *domain,
                           unsigned long start_pfn,
                           unsigned long last_pfn)
 {
-        int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
         struct page *freelist = NULL;
 
-        BUG_ON(addr_width < BITS_PER_LONG && start_pfn >> addr_width);
-        BUG_ON(addr_width < BITS_PER_LONG && last_pfn >> addr_width);
+        BUG_ON(!domain_pfn_supported(domain, start_pfn));
+        BUG_ON(!domain_pfn_supported(domain, last_pfn));
         BUG_ON(start_pfn > last_pfn);
 
         /* we don't need lock here; nobody else touches the iova range */
@@ -1974,12 +1977,11 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
 {
         struct dma_pte *first_pte = NULL, *pte = NULL;
         phys_addr_t uninitialized_var(pteval);
-        int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
         unsigned long sg_res;
         unsigned int largepage_lvl = 0;
         unsigned long lvl_pages = 0;
 
-        BUG_ON(addr_width < BITS_PER_LONG && (iov_pfn + nr_pages - 1) >> addr_width);
+        BUG_ON(!domain_pfn_supported(domain, iov_pfn + nr_pages - 1));
 
         if ((prot & (DMA_PTE_READ|DMA_PTE_WRITE)) == 0)
                 return -EINVAL;