From 6a62924c0a81316b2aff713566593405b57545d5 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Tue, 5 Apr 2022 14:40:55 +0100 Subject: [PATCH] sfc: Stop using iommu_present() Even if an IOMMU might be present for some PCI segment in the system, that doesn't necessarily mean it provides translation for the device we care about. It appears that what we care about here is specifically whether DMA mapping ops involve any IOMMU overhead or not, so check for translation actually being active for our device. Signed-off-by: Robin Murphy Acked-by: Edward Cree Link: https://lore.kernel.org/r/7350f957944ecfce6cce90f422e3992a1f428775.1649166055.git.robin.murphy@arm.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/sfc/falcon/rx.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/sfc/falcon/rx.c b/drivers/net/ethernet/sfc/falcon/rx.c index 0c6cc21..6bbdb5d 100644 --- a/drivers/net/ethernet/sfc/falcon/rx.c +++ b/drivers/net/ethernet/sfc/falcon/rx.c @@ -718,12 +718,14 @@ static void ef4_init_rx_recycle_ring(struct ef4_nic *efx, struct ef4_rx_queue *rx_queue) { unsigned int bufs_in_recycle_ring, page_ring_size; + struct iommu_domain __maybe_unused *domain; /* Set the RX recycle ring size */ #ifdef CONFIG_PPC64 bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_IOMMU; #else - if (iommu_present(&pci_bus_type)) + domain = iommu_get_domain_for_dev(&efx->pci_dev->dev); + if (domain && domain->type != IOMMU_DOMAIN_IDENTITY) bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_IOMMU; else bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_NOIOMMU; -- 2.7.4