From c76c067e488ccd55734c3e750799caf2c5956db6 Mon Sep 17 00:00:00 2001 From: Niklas Schnelle Date: Thu, 28 Sep 2023 16:31:37 +0200 Subject: s390/pci: Use dma-iommu layer While s390 already has a standard IOMMU driver and previous changes have added I/O TLB flushing operations this driver is currently only used for user-space PCI access such as vfio-pci. For the DMA API s390 instead utilizes its own implementation in arch/s390/pci/pci_dma.c which drives the same hardware and shares some code but requires a complex and fragile hand over between DMA API and IOMMU API use of a device and despite code sharing still leads to significant duplication and maintenance effort. Let's utilize the common code DMAP API implementation from drivers/iommu/dma-iommu.c instead allowing us to get rid of arch/s390/pci/pci_dma.c. Reviewed-by: Matthew Rosato Signed-off-by: Niklas Schnelle Link: https://lore.kernel.org/r/20230928-dma_iommu-v13-3-9e5fc4dacc36@linux.ibm.com Signed-off-by: Joerg Roedel --- Documentation/admin-guide/kernel-parameters.txt | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'Documentation/admin-guide/kernel-parameters.txt') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 0a1731a0f0ef..14f56c448edc 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2220,7 +2220,7 @@ forcing Dual Address Cycle for PCI cards supporting greater than 32-bit addressing. - iommu.strict= [ARM64, X86] Configure TLB invalidation behaviour + iommu.strict= [ARM64, X86, S390] Configure TLB invalidation behaviour Format: { "0" | "1" } 0 - Lazy mode. Request that DMA unmap operations use deferred @@ -5611,9 +5611,10 @@ s390_iommu= [HW,S390] Set s390 IOTLB flushing mode strict - With strict flushing every unmap operation will result in - an IOTLB flush. Default is lazy flushing before reuse, - which is faster. + With strict flushing every unmap operation will result + in an IOTLB flush. Default is lazy flushing before + reuse, which is faster. Deprecated, equivalent to + iommu.strict=1. s390_iommu_aperture= [KNL,S390] Specifies the size of the per device DMA address space -- cgit