From: Leonardo Bras leobras.c@gmail.com
[ Upstream commit a9d2f9bb225fd2a764aef57738ab6c7f38d782ae ]
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 leobras.c@gmail.com Reviewed-by: Alexey Kardashevskiy aik@ozlabs.ru Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20210420045404.438735-1-leobras.c@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 9fc5217f0c8e..836cbbe0ecc5 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -1229,7 +1229,7 @@ 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"); }