iommu/vt-d: Clean up iommu_no_mapping

Invert the return value to avoid double negatives, use a bool
instead of int as the return value, and reduce some indentation
after early returns.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index c137f0f..46337a4 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3608,45 +3608,40 @@ out:
 }
 
 /* Check if the dev needs to go through non-identity map and unmap process.*/
-static int iommu_no_mapping(struct device *dev)
+static bool iommu_need_mapping(struct device *dev)
 {
        int found;
 
        if (iommu_dummy(dev))
-               return 1;
+               return false;
 
        if (!iommu_identity_mapping)
-               return 0;
+               return true;
 
        found = identity_mapping(dev);
        if (found) {
                if (iommu_should_identity_map(dev, 0))
-                       return 1;
-               else {
-                       /*
-                        * 32 bit DMA is removed from si_domain and fall back
-                        * to non-identity mapping.
-                        */
-                       dmar_remove_one_dev_info(dev);
-                       dev_info(dev, "32bit DMA uses non-identity mapping\n");
-                       return 0;
-               }
+                       return false;
+
+               /*
+                * 32 bit DMA is removed from si_domain and fall back to
+                * non-identity mapping.
+                */
+               dmar_remove_one_dev_info(dev);
+               dev_info(dev, "32bit DMA uses non-identity mapping\n");
        } else {
                /*
                 * In case of a detached 64 bit DMA device from vm, the device
                 * is put into si_domain for identity mapping.
                 */
-               if (iommu_should_identity_map(dev, 0)) {
-                       int ret;
-                       ret = domain_add_dev_info(si_domain, dev);
-                       if (!ret) {
-                               dev_info(dev, "64bit DMA uses identity mapping\n");
-                               return 1;
-                       }
+               if (iommu_should_identity_map(dev, 0) &&
+                   !domain_add_dev_info(si_domain, dev)) {
+                       dev_info(dev, "64bit DMA uses identity mapping\n");
+                       return false;
                }
        }
 
-       return 0;
+       return true;
 }
 
 static dma_addr_t __intel_map_single(struct device *dev, phys_addr_t paddr,
@@ -3662,7 +3657,7 @@ static dma_addr_t __intel_map_single(struct device *dev, phys_addr_t paddr,
 
        BUG_ON(dir == DMA_NONE);
 
-       if (iommu_no_mapping(dev))
+       if (!iommu_need_mapping(dev))
                return paddr;
 
        domain = get_valid_domain_for_dev(dev);
@@ -3733,7 +3728,7 @@ static void intel_unmap(struct device *dev, dma_addr_t dev_addr, size_t size)
        struct intel_iommu *iommu;
        struct page *freelist;
 
-       if (iommu_no_mapping(dev))
+       if (!iommu_need_mapping(dev))
                return;
 
        domain = find_domain(dev);
@@ -3784,7 +3779,7 @@ static void *intel_alloc_coherent(struct device *dev, size_t size,
        size = PAGE_ALIGN(size);
        order = get_order(size);
 
-       if (!iommu_no_mapping(dev))
+       if (iommu_need_mapping(dev))
                flags &= ~(GFP_DMA | GFP_DMA32);
        else if (dev->coherent_dma_mask < dma_get_required_mask(dev)) {
                if (dev->coherent_dma_mask < DMA_BIT_MASK(32))
@@ -3798,7 +3793,7 @@ static void *intel_alloc_coherent(struct device *dev, size_t size,
 
                page = dma_alloc_from_contiguous(dev, count, order,
                                                 flags & __GFP_NOWARN);
-               if (page && iommu_no_mapping(dev) &&
+               if (page && !iommu_need_mapping(dev) &&
                    page_to_phys(page) + size > dev->coherent_dma_mask) {
                        dma_release_from_contiguous(dev, page, count);
                        page = NULL;
@@ -3880,7 +3875,7 @@ static int intel_map_sg(struct device *dev, struct scatterlist *sglist, int nele
        struct intel_iommu *iommu;
 
        BUG_ON(dir == DMA_NONE);
-       if (iommu_no_mapping(dev))
+       if (!iommu_need_mapping(dev))
                return intel_nontranslate_map_sg(dev, sglist, nelems, dir);
 
        domain = get_valid_domain_for_dev(dev);