iommu/dma: Use fast DMA domain lookup

Most parts of iommu-dma already assume they are operating on a default
domain set up by iommu_dma_init_domain(), and can be converted straight
over to avoid the refcounting bottleneck. MSI page mappings may be in
an unmanaged domain with an explicit MSI-only cookie, so retain the
non-specific lookup, but that's OK since they're far from a contended
fast path either way.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 12 insertions, 11 deletions

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 511ff9a1d6d9..320f9ea82f3f 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -491,7 +491,7 @@ static struct page **__iommu_dma_alloc_pages(unsigned int count,
 void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
                 dma_addr_t *handle)
 {
-        __iommu_dma_unmap(iommu_get_domain_for_dev(dev), *handle, size);
+        __iommu_dma_unmap(iommu_get_dma_domain(dev), *handle, size);
         __iommu_dma_free_pages(pages, PAGE_ALIGN(size) >> PAGE_SHIFT);
         *handle = IOMMU_MAPPING_ERROR;
 }
@@ -518,7 +518,7 @@ struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
                 unsigned long attrs, int prot, dma_addr_t *handle,
                 void (*flush_page)(struct device *, const void *, phys_addr_t))
 {
-        struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+        struct iommu_domain *domain = iommu_get_dma_domain(dev);
         struct iommu_dma_cookie *cookie = domain->iova_cookie;
         struct iova_domain *iovad = &cookie->iovad;
         struct page **pages;
@@ -606,9 +606,8 @@ int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma)
 }
 
 static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
-                size_t size, int prot)
+                size_t size, int prot, struct iommu_domain *domain)
 {
-        struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
         struct iommu_dma_cookie *cookie = domain->iova_cookie;
         size_t iova_off = 0;
         dma_addr_t iova;
@@ -632,13 +631,14 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
 dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
                 unsigned long offset, size_t size, int prot)
 {
-        return __iommu_dma_map(dev, page_to_phys(page) + offset, size, prot);
+        return __iommu_dma_map(dev, page_to_phys(page) + offset, size, prot,
+                        iommu_get_dma_domain(dev));
 }
 
 void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
                 enum dma_data_direction dir, unsigned long attrs)
 {
-        __iommu_dma_unmap(iommu_get_domain_for_dev(dev), handle, size);
+        __iommu_dma_unmap(iommu_get_dma_domain(dev), handle, size);
 }
 
 /*
@@ -726,7 +726,7 @@ static void __invalidate_sg(struct scatterlist *sg, int nents)
 int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
                 int nents, int prot)
 {
-        struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+        struct iommu_domain *domain = iommu_get_dma_domain(dev);
         struct iommu_dma_cookie *cookie = domain->iova_cookie;
         struct iova_domain *iovad = &cookie->iovad;
         struct scatterlist *s, *prev = NULL;
@@ -811,20 +811,21 @@ void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
                 sg = tmp;
         }
         end = sg_dma_address(sg) + sg_dma_len(sg);
-        __iommu_dma_unmap(iommu_get_domain_for_dev(dev), start, end - start);
+        __iommu_dma_unmap(iommu_get_dma_domain(dev), start, end - start);
 }
 
 dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys,
                 size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
         return __iommu_dma_map(dev, phys, size,
-                        dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO);
+                        dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO,
+                        iommu_get_dma_domain(dev));
 }
 
 void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
                 size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
-        __iommu_dma_unmap(iommu_get_domain_for_dev(dev), handle, size);
+        __iommu_dma_unmap(iommu_get_dma_domain(dev), handle, size);
 }
 
 int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
@@ -850,7 +851,7 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
         if (!msi_page)
                 return NULL;
 
-        iova = __iommu_dma_map(dev, msi_addr, size, prot);
+        iova = __iommu_dma_map(dev, msi_addr, size, prot, domain);
         if (iommu_dma_mapping_error(dev, iova))
                 goto out_free_page;