On 2019-11-20 10:48 a.m., Dmitry Safonov wrote: > +Cc: [email protected] > +Cc: Bjorn Helgaas <[email protected]> > +Cc: Logan Gunthorpe <[email protected]> > > On 11/5/19 12:17 PM, James Sewart wrote: >> Any comments on this? >> >> Cheers, >> James. >> >>> On 24 Oct 2019, at 13:52, James Sewart <[email protected]> wrote: >>> >>> The PLX PEX NTB forwards DMA transactions using Requester ID's that don't >>> exist as >>> PCI devices. The devfn for a transaction is used as an index into a lookup >>> table >>> storing the origin of a transaction on the other side of the bridge. >>> >>> This patch aliases all possible devfn's to the NTB device so that any >>> transaction >>> coming in is governed by the mappings for the NTB. >>> >>> Signed-Off-By: James Sewart <[email protected]> >>> --- >>> drivers/pci/quirks.c | 22 ++++++++++++++++++++++ >>> 1 file changed, 22 insertions(+) >>> >>> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c >>> index 320255e5e8f8..647f546e427f 100644 >>> --- a/drivers/pci/quirks.c >>> +++ b/drivers/pci/quirks.c >>> @@ -5315,6 +5315,28 @@ SWITCHTEC_QUIRK(0x8574); /* PFXI 64XG3 */ >>> SWITCHTEC_QUIRK(0x8575); /* PFXI 80XG3 */ >>> SWITCHTEC_QUIRK(0x8576); /* PFXI 96XG3 */ >>> >>> +/* >>> + * PLX NTB uses devfn proxy IDs to move TLPs between NT endpoints. These >>> IDs >>> + * are used to forward responses to the originator on the other side of the >>> + * NTB. Alias all possible IDs to the NTB to permit access when the IOMMU >>> is >>> + * turned on. >>> + */ >>> +static void quirk_PLX_NTB_dma_alias(struct pci_dev *pdev) >>> +{ >>> + if (!pdev->dma_alias_mask) >>> + pdev->dma_alias_mask = kcalloc(BITS_TO_LONGS(U8_MAX), >>> + sizeof(long), GFP_KERNEL); >>> + if (!pdev->dma_alias_mask) { >>> + dev_warn(&pdev->dev, "Unable to allocate DMA alias mask\n"); >>> + return; >>> + } >>> + >>> + // PLX NTB may use all 256 devfns >>> + memset(pdev->dma_alias_mask, U8_MAX, (U8_MAX+1)/BITS_PER_BYTE); I think it would be better to create a pci_add_dma_alias_range() function instead of directly accessing dma_alias_mask. We could then use that function to clean up quirk_switchtec_ntb_dma_alias() which is essentially doing the same thing. It's also quite ugly that you're allocating with kcalloc here instead of bitmap_zalloc() seeing it will be free'd with bitmap_free(). Also, you should probably use bitmap_set() instead of memset(). Logan _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
