[PATCH v3 1/6] iommu/dma: Disable get_sgtable for granule > PAGE_SIZE

Sven Peter
2021-10-19T16:38:56Z

While this function *probably* works correctly without any changes for
granule > PAGE_SIZE I don't have any code to actually test it and cannot
reason about how the function is supposed to work.
Disable it instead until we run into a use case where it's required.

Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
drivers/iommu/dma-iommu.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index de5040b65529..17f25632a0d6 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1249,9 +1249,15 @@ static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
{
+ 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 *page;
int ret;

+ if (iovad->granule > PAGE_SIZE)
+ return -ENXIO;
+
if (IS_ENABLED(CONFIG_DMA_REMAP) && is_vmalloc_addr(cpu_addr)) {
struct page **pages = dma_common_find_pages(cpu_addr);

--
2.25.1