From: John Ernberg Date: Mon, 12 May 2025 07:14:50 +0000 (+0000) Subject: xen: swiotlb: Wire up map_resource callback X-Git-Tag: v6.16-rc1~158^2~3 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=406251a408f51a5ff1b7d41a1d590b35aff5b0fa;p=thirdparty%2Fkernel%2Flinux.git xen: swiotlb: Wire up map_resource callback When running Xen on iMX8QXP, an Arm SoC without IOMMU, DMA performed via its eDMA v3 DMA engine fail with a mapping error. The eDMA performs DMA between RAM and MMIO space, and it's the MMIO side that cannot be mapped. MMIO->RAM DMA access cannot be bounce buffered if it would straddle a page boundary and on Xen the MMIO space is 1:1 mapped for Arm, and x86 PV Dom0. Cases where MMIO space is not 1:1 mapped, such as x86 PVH Dom0, requires an IOMMU present to deal with the mapping. Considering the above the map_resource callback can just be wired to the existing dma_direct_map_resource() function. There is nothing to do for unmap so the unmap callback is not needed. Signed-off-by: John Ernberg Reviewed-by: Stefano Stabellini Message-ID: <20250512071440.3726697-1-john.ernberg@actia.se> Signed-off-by: Juergen Gross --- diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index ef56a2500ed69..da1a7d3d377cf 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -426,4 +426,5 @@ const struct dma_map_ops xen_swiotlb_dma_ops = { .alloc_pages_op = dma_common_alloc_pages, .free_pages = dma_common_free_pages, .max_mapping_size = swiotlb_max_mapping_size, + .map_resource = dma_direct_map_resource, };