From a9d2f9bb225fd2a764aef57738ab6c7f38d782ae Mon Sep 17 00:00:00 2001 From: Leonardo Bras Date: Tue, 20 Apr 2021 01:54:04 -0300 Subject: [PATCH] powerpc/pseries/iommu: Fix window size for direct mapping with pmem As of today, if the DDW is big enough to fit (1 << MAX_PHYSMEM_BITS) it's possible to use direct DMA mapping even with pmem region. But, if that happens, the window size (len) is set to (MAX_PHYSMEM_BITS - page_shift) instead of MAX_PHYSMEM_BITS, causing a pagesize times smaller DDW to be created, being insufficient for correct usage. Fix this so the correct window size is used in this case. Fixes: bf6e2d562bbc4 ("powerpc/dma: Fallback to dma_ops when persistent memory present") Signed-off-by: Leonardo Bras Reviewed-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210420045404.438735-1-leobras.c@gmail.com --- arch/powerpc/platforms/pseries/iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c index 67c9953a6503..5b3050ff0c55 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -1252,7 +1252,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn) if (pmem_present) { if (query.largest_available_block >= (1ULL << (MAX_PHYSMEM_BITS - page_shift))) - len = MAX_PHYSMEM_BITS - page_shift; + len = MAX_PHYSMEM_BITS; else dev_info(&dev->dev, "Skipping ibm,pmemory"); } -- 2.11.0