Commit d5b5e814 authored by Stian Halseth's avatar Stian Halseth Committed by Marek Szyprowski
Browse files

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: 38c0d0eb ("sparc: Use physical address DMA mapping")
Reported-by: default avatarStian Halseth <stian@itx.no>
Closes: https://github.com/sparclinux/issues/issues/75


Suggested-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: default avatarStian Halseth <stian@itx.no>
Tested-by: default avatarNathaniel Roach <nroach44@nroach44.id.au>
Tested-by: Han Gao <gaohan@iscas.ac.cn> # on SPARC Enterprise T5220
[mszyprow: adjusted commit description a bit]
Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20260218120056.3366-2-stian@itx.no
parent 47322c46

arch/sparc/kernel/iommu.c

+2 −0
Original line number Diff line number Diff line
@@ -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;

arch/sparc/kernel/pci_sun4v.c

+2 −0
Original line number Diff line number Diff line
@@ -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))