[PATCH 05/14] PCI/P2PDMA: Factor out host_bridge_whitelist()

Logan Gunthorpe
2019-07-22T23:09:57Z

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.

Signed-off-by: Logan Gunthorpe <logang@deltatee.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 25663c1d8bc9..dfb802afc8ca 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -250,19 +250,11 @@ 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;

@@ -277,6 +269,24 @@ 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;
+}
+
enum {
/*
* Thes arbitrary offset are or'd onto the upstream distance
@@ -412,8 +422,7 @@ static int upstream_bridge_distance(struct pci_dev *provider,
if (!(dist & P2PDMA_THRU_HOST_BRIDGE))
goto store_and_return;

- if (!root_complex_whitelist(provider) ||
- !root_complex_whitelist(client))
+ if (!host_bridge_whitelist(provider, client))
dist |= P2PDMA_NOT_SUPPORTED;

store_and_return:
--
2.20.1