From d5b5e8149af0f5efed58653cbebf1cb3258ce49a Mon Sep 17 00:00:00 2001 From: Stian Halseth Date: Wed, 18 Feb 2026 13:00:24 +0100 Subject: [PATCH] sparc: Fix page alignment in dma mapping 'phys' may include an offset within the page, while previously used 'base_paddr' was already page-aligned. This caused incorrect DMA mapping in dma_4u_map_phys and dma_4v_map_phys. Fix both functions by masking 'phys' with IO_PAGE_MASK, covering both generic SPARC code and sun4v. Fixes: 38c0d0ebf520 ("sparc: Use physical address DMA mapping") Reported-by: Stian Halseth Closes: https://github.com/sparclinux/issues/issues/75 Suggested-by: Marek Szyprowski Signed-off-by: Stian Halseth Tested-by: Nathaniel Roach Tested-by: Han Gao # on SPARC Enterprise T5220 [mszyprow: adjusted commit description a bit] Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20260218120056.3366-2-stian@itx.no --- arch/sparc/kernel/iommu.c | 2 ++ arch/sparc/kernel/pci_sun4v.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c index 46ef88bc9c26..7613ab0ffb89 100644 --- a/arch/sparc/kernel/iommu.c +++ b/arch/sparc/kernel/iommu.c @@ -312,6 +312,8 @@ static dma_addr_t dma_4u_map_phys(struct device *dev, phys_addr_t phys, if (direction != DMA_TO_DEVICE) iopte_protection |= IOPTE_WRITE; + phys &= IO_PAGE_MASK; + for (i = 0; i < npages; i++, base++, phys += IO_PAGE_SIZE) iopte_val(*base) = iopte_protection | phys; diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c index 440284cc804e..61f14b4c8f90 100644 --- a/arch/sparc/kernel/pci_sun4v.c +++ b/arch/sparc/kernel/pci_sun4v.c @@ -410,6 +410,8 @@ static dma_addr_t dma_4v_map_phys(struct device *dev, phys_addr_t phys, iommu_batch_start(dev, prot, entry); + phys &= IO_PAGE_MASK; + for (i = 0; i < npages; i++, phys += IO_PAGE_SIZE) { long err = iommu_batch_add(phys, mask); if (unlikely(err < 0L))