From 419dbd5e1ff0e45a6e1d28c1f7b74d121d2a56e7 Mon Sep 17 00:00:00 2001 From: Alistair Popple Date: Fri, 8 Jan 2016 11:35:09 +1100 Subject: [PATCH] powerpc/powernv: Fix update of NVLink DMA mask The emulated NVLink PCI devices share the same IODA2 TCE tables but only support a single TVT (instead of the normal two for PCI devices). This requires the kernel to manually replace windows with either the bypass or non-bypass window depending on what the driver has requested. Unfortunately an incorrect optimisation was made in pnv_pci_ioda_dma_set_mask() which caused updating of some NPU device PEs to be skipped in certain configurations due to an incorrect assumption that a NULL peer PE in the array indicated there were no more peers present. This patch fixes the problem by ensuring all peer PEs are updated. Fixes: 5d2aa710e697 ("powerpc/powernv: Add support for Nvlink NPUs") Signed-off-by: Alistair Popple Signed-off-by: Michael Ellerman --- arch/powerpc/platforms/powernv/pci-ioda.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index 323e1e58da93..458133f3c020 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -1612,7 +1612,10 @@ static int pnv_pci_ioda_dma_set_mask(struct pci_dev *pdev, u64 dma_mask) /* Update peer npu devices */ if (pe->flags & PNV_IODA_PE_PEER) - for (i = 0; pe->peers[i]; i++) { + for (i = 0; i < PNV_IODA_MAX_PEER_PES; i++) { + if (!pe->peers[i]) + continue; + linked_npu_dev = pe->peers[i]->pdev; if (dma_get_mask(&linked_npu_dev->dev) != dma_mask) dma_set_mask(&linked_npu_dev->dev, dma_mask); -- 2.20.1