[PATCH v3 06/14] PCI/P2PDMA: Factor out host_bridge_whitelist()

Logan Gunthorpe
2019-08-12T17:31:07Z

Push both PCI devices into the whitelist checking function seeing some
hardware will require us ensuring they are on the same host bridge.

At the same time we rename root_complex_whitelist() to
host_bridge_whitelist() to match the terminology used in the code.

Link: https://lore.kernel.org/r/20190730163545.4915-7-logang@deltatee.com
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
drivers/pci/p2pdma.c | 31 ++++++++++++++++++++-----------
1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index f7f7e5862bab..4b9f0903b340 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -269,19 +269,11 @@ static void seq_buf_print_bus_devfn(struct seq_buf *buf, struct pci_dev *pdev)
seq_buf_printf(buf, "%s;", pci_name(pdev));
}

-/*
- * If we can't find a common upstream bridge take a look at the root
- * complex and compare it to a whitelist of known good hardware.
- */
-static bool root_complex_whitelist(struct pci_dev *dev)
+static bool __host_bridge_whitelist(struct pci_host_bridge *host)
{
- struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
struct pci_dev *root = pci_get_slot(host->bus, PCI_DEVFN(0, 0));
unsigned short vendor, device;

- if (iommu_present(dev->dev.bus))
- return false;
-
if (!root)
return false;

@@ -296,6 +288,24 @@ static bool root_complex_whitelist(struct pci_dev *dev)
return false;
}

+/*
+ * If we can't find a common upstream bridge take a look at the root
+ * complex and compare it to a whitelist of known good hardware.
+ */
+static bool host_bridge_whitelist(struct pci_dev *a, struct pci_dev *b)
+{
+ struct pci_host_bridge *host_a = pci_find_host_bridge(a->bus);
+ struct pci_host_bridge *host_b = pci_find_host_bridge(b->bus);
+
+ if (iommu_present(a->dev.bus) || iommu_present(b->dev.bus))
+ return false;
+
+ if (__host_bridge_whitelist(host_a) && __host_bridge_whitelist(host_b))
+ return true;
+
+ return false;
+}
+
static enum pci_p2pdma_map_type
__upstream_bridge_distance(struct pci_dev *provider, struct pci_dev *client,
int *dist, bool *acs_redirects, struct seq_buf *acs_list)
@@ -418,8 +428,7 @@ upstream_bridge_distance(struct pci_dev *provider, struct pci_dev *client,
acs_redirects, acs_list);

if (map_type == PCI_P2PDMA_MAP_THRU_HOST_BRIDGE) {
- if (!root_complex_whitelist(provider) ||
- !root_complex_whitelist(client))
+ if (!host_bridge_whitelist(provider, client))
return PCI_P2PDMA_MAP_NOT_SUPPORTED;
}

--
2.20.1