[PATCH 2/2] dma-iommu: Check CONFIG_SWIOTLB more broadly

From: David Stevens
Date: Fri Jul 02 2021 - 01:54:15 EST


From: David Stevens <stevensd@xxxxxxxxxxxx>

Add check for CONFIG_SWIOTLB to dev_is_untrusted, so that swiotlb
related code can be removed more aggressively.

Signed-off-by: David Stevens <stevensd@xxxxxxxxxxxx>
---
drivers/iommu/dma-iommu.c | 26 +++++++++++++-------------
1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 24d1042cd052..614f0dd86b08 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -310,9 +310,10 @@ static void iommu_dma_flush_iotlb_all(struct iova_domain *iovad)
domain->ops->flush_iotlb_all(domain);
}

-static bool dev_is_untrusted(struct device *dev)
+static bool dev_use_swiotlb(struct device *dev)
{
- return dev_is_pci(dev) && to_pci_dev(dev)->untrusted;
+ return IS_ENABLED(CONFIG_SWIOTLB) &&
+ dev_is_pci(dev) && to_pci_dev(dev)->untrusted;
}

/**
@@ -368,7 +369,7 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,

init_iova_domain(iovad, 1UL << order, base_pfn);

- if (!cookie->fq_domain && (!dev || !dev_is_untrusted(dev)) &&
+ if (!cookie->fq_domain && (!dev || !dev_use_swiotlb(dev)) &&
domain->ops->flush_iotlb_all && !iommu_get_dma_strict(domain)) {
if (init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all,
iommu_dma_entry_dtor))
@@ -553,8 +554,7 @@ static dma_addr_t __iommu_dma_map_swiotlb(struct device *dev, phys_addr_t phys,
* If both the physical buffer start address and size are
* page aligned, we don't need to use a bounce page.
*/
- if (IS_ENABLED(CONFIG_SWIOTLB) && dev_is_untrusted(dev) &&
- iova_offset(iovad, phys | org_size)) {
+ if (dev_use_swiotlb(dev) && iova_offset(iovad, phys | org_size)) {
aligned_size = iova_align(iovad, org_size);
phys = swiotlb_tbl_map_single(dev, phys, org_size,
aligned_size, dir,
@@ -779,7 +779,7 @@ static void iommu_dma_sync_single_for_cpu(struct device *dev,
{
phys_addr_t phys;

- if (dev_is_dma_coherent(dev) && !dev_is_untrusted(dev))
+ if (dev_is_dma_coherent(dev) && !dev_use_swiotlb(dev))
return;

phys = iommu_iova_to_phys(iommu_get_dma_domain(dev), dma_handle);
@@ -794,7 +794,7 @@ static void __iommu_dma_sync_single_for_device(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction dir, phys_addr_t phys)
{
- if (dev_is_dma_coherent(dev) && !dev_is_untrusted(dev))
+ if (dev_is_dma_coherent(dev) && !dev_use_swiotlb(dev))
return;

if (phys == 0)
@@ -821,10 +821,10 @@ static void iommu_dma_sync_sg_for_cpu(struct device *dev,
struct scatterlist *sg;
int i;

- if (dev_is_dma_coherent(dev) && !dev_is_untrusted(dev))
+ if (dev_is_dma_coherent(dev) && !dev_use_swiotlb(dev))
return;

- if (dev_is_untrusted(dev))
+ if (dev_use_swiotlb(dev))
for_each_sg(sgl, sg, nelems, i)
iommu_dma_sync_single_for_cpu(dev, sg_dma_address(sg),
sg->length, dir);
@@ -840,10 +840,10 @@ static void iommu_dma_sync_sg_for_device(struct device *dev,
struct scatterlist *sg;
int i;

- if (dev_is_dma_coherent(dev) && !dev_is_untrusted(dev))
+ if (dev_is_dma_coherent(dev) && !dev_use_swiotlb(dev))
return;

- if (dev_is_untrusted(dev))
+ if (dev_use_swiotlb(dev))
for_each_sg(sgl, sg, nelems, i)
__iommu_dma_sync_single_for_device(dev,
sg_dma_address(sg),
@@ -1010,7 +1010,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
iommu_deferred_attach(dev, domain))
return 0;

- if (dev_is_untrusted(dev)) {
+ if (dev_use_swiotlb(dev)) {
early_mapped = iommu_dma_map_sg_swiotlb(dev, sg, nents,
dir, attrs);
if (!early_mapped)
@@ -1092,7 +1092,7 @@ static void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
iommu_dma_sync_sg_for_cpu(dev, sg, nents, dir);

- if (dev_is_untrusted(dev)) {
+ if (dev_use_swiotlb(dev)) {
iommu_dma_unmap_sg_swiotlb(dev, sg, nents, dir, attrs);
return;
}
--
2.32.0.93.g670b81a890-goog