6.12-stable review patch. If anyone has any objections, please let me know.
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From: John Ernberg john.ernberg@actia.se
commit cd9c058489053e172a6654cad82ee936d1b09fab upstream.
Xen swiotlb support was missed when the patch set starting with 4ab5f8ec7d71 ("mm/slab: decouple ARCH_KMALLOC_MINALIGN from ARCH_DMA_MINALIGN") was merged.
When running Xen on iMX8QXP, a SoC without IOMMU, the effect was that USB transfers ended up corrupted when there was more than one URB inflight at the same time.
Add a call to dma_kmalloc_needs_bounce() to make sure that allocations too small for DMA get bounced via swiotlb.
Closes: https://lore.kernel.org/linux-usb/ab2776f0-b838-4cf6-a12a-c208eb6aad59@actia... Fixes: 4ab5f8ec7d71 ("mm/slab: decouple ARCH_KMALLOC_MINALIGN from ARCH_DMA_MINALIGN") Cc: stable@kernel.org # v6.5+ Signed-off-by: John Ernberg john.ernberg@actia.se Reviewed-by: Stefano Stabellini sstabellini@kernel.org Signed-off-by: Juergen Gross jgross@suse.com Message-ID: 20250502114043.1968976-2-john.ernberg@actia.se Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/xen/swiotlb-xen.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -217,6 +217,7 @@ static dma_addr_t xen_swiotlb_map_page(s * buffering it. */ if (dma_capable(dev, dev_addr, size, true) && + !dma_kmalloc_needs_bounce(dev, size, dir) && !range_straddles_page_boundary(phys, size) && !xen_arch_need_swiotlb(dev, phys, dev_addr) && !is_swiotlb_force_bounce(dev))