[PATCH] iommu/dma: Clean up redundant MSI cookie check

From: Robin Murphy

Date: Fri Oct 02 2026 - 12:37:21 EST


The has_msi_cookie() condition only mattered transiently as an artefact
of the cookie rework being done in parallel with the sw_msi rework. Once
combined, calls to iommu_dma_sw_msi() are themselves dispatched based on
domain->cookie_type, so checking again is clearly redundant.

Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
---
drivers/iommu/dma-iommu.c | 11 -----------
1 file changed, 11 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 1b8012123232..5d9d282540bc 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -2162,12 +2162,6 @@ void iommu_setup_dma_ops(struct device *dev, struct iommu_domain *domain)
dev_clear_dma_iommu(dev);
}

-static bool has_msi_cookie(const struct iommu_domain *domain)
-{
- return domain && (domain->cookie_type == IOMMU_COOKIE_DMA_IOVA ||
- domain->cookie_type == IOMMU_COOKIE_DMA_MSI);
-}
-
static size_t cookie_msi_granule(const struct iommu_domain *domain)
{
switch (domain->cookie_type) {
@@ -2249,11 +2243,6 @@ int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
struct device *dev = msi_desc_to_dev(desc);
const struct iommu_dma_msi_page *msi_page;

- if (!has_msi_cookie(domain)) {
- msi_desc_set_iommu_msi_iova(desc, 0, 0);
- return 0;
- }
-
iommu_group_mutex_assert(dev);
msi_page = iommu_dma_get_msi_page(dev, msi_addr, domain);
if (!msi_page)
--
2.54.0.dirty