[Patch Part3 V4 11/21] iommu/vt-d: Introduce helper domain_pfn_within_range() to simplify code

Jiang Liu
2014-07-11T06:17:35Z

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

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
drivers/iommu/intel-iommu.c | 30 ++++++++++++++++--------------
1 file 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;
--
1.7.10.4