From 719c98658058f4aca0f7663ff11f2606e99cce4f Mon Sep 17 00:00:00 2001 From: Logan Gunthorpe Date: Fri, 8 Jul 2022 10:50:53 -0600 Subject: [PATCH] PCI/P2PDMA: Attempt to set map_type if it has not been set Attempt to find the mapping type for P2PDMA pages on the first DMA map attempt if it has not been done ahead of time. Previously, the mapping type was expected to be calculated ahead of time, but if pages are to come from userspace then there's no way to ensure the path was checked ahead of time. This change will calculate the mapping type if it hasn't pre-calculated so it is no longer invalid to call pci_p2pdma_map_sg() before the mapping type is calculated, so drop the WARN_ON when that is the case. Signed-off-by: Logan Gunthorpe Acked-by: Bjorn Helgaas Reviewed-by: Chaitanya Kulkarni Reviewed-by: Christoph Hellwig Signed-off-by: Christoph Hellwig --- drivers/pci/p2pdma.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index 462b429ad2434..4e8bc457e29ab 100644 --- a/drivers/pci/p2pdma.c +++ b/drivers/pci/p2pdma.c @@ -854,6 +854,7 @@ static enum pci_p2pdma_map_type pci_p2pdma_map_type(struct dev_pagemap *pgmap, struct pci_dev *provider = to_p2p_pgmap(pgmap)->provider; struct pci_dev *client; struct pci_p2pdma *p2pdma; + int dist; if (!provider->p2pdma) return PCI_P2PDMA_MAP_NOT_SUPPORTED; @@ -870,6 +871,10 @@ static enum pci_p2pdma_map_type pci_p2pdma_map_type(struct dev_pagemap *pgmap, type = xa_to_value(xa_load(&p2pdma->map_types, map_types_idx(client))); rcu_read_unlock(); + + if (type == PCI_P2PDMA_MAP_UNKNOWN) + return calc_map_type_and_dist(provider, client, &dist, true); + return type; } @@ -912,7 +917,7 @@ int pci_p2pdma_map_sg_attrs(struct device *dev, struct scatterlist *sg, case PCI_P2PDMA_MAP_BUS_ADDR: return __pci_p2pdma_map_sg(p2p_pgmap, dev, sg, nents); default: - WARN_ON_ONCE(1); + /* Mapping is not Supported */ return 0; } } -- 2.30.2