This is a prep patch to create a second level helper. There are no functional changes. The root complex whitelist code will be moved into this function in a subsequent patch. Link: https://lore.kernel.org/r/20190730163545.4915-5-logang@xxxxxxxxxxxx Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Reviewed-by: Christian König <christian.koenig@xxxxxxx> --- drivers/pci/p2pdma.c | 88 ++++++++++++++++++++++++-------------------- 1 file changed, 48 insertions(+), 40 deletions(-) diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index 8f0688201aec..600ba6a7aa11 100644 --- a/drivers/pci/p2pdma.c +++ b/drivers/pci/p2pdma.c @@ -296,47 +296,8 @@ static bool root_complex_whitelist(struct pci_dev *dev) return false; } -/* - * Find the distance through the nearest common upstream bridge between - * two PCI devices. - * - * If the two devices are the same device then 0 will be returned. - * - * If there are two virtual functions of the same device behind the same - * bridge port then 2 will be returned (one step down to the PCIe switch, - * then one step back to the same device). - * - * In the case where two devices are connected to the same PCIe switch, the - * value 4 will be returned. This corresponds to the following PCI tree: - * - * -+ Root Port - * \+ Switch Upstream Port - * +-+ Switch Downstream Port - * + \- Device A - * \-+ Switch Downstream Port - * \- Device B - * - * The distance is 4 because we traverse from Device A through the downstream - * port of the switch, to the common upstream port, back up to the second - * downstream port and then to Device B. - * - * Any two devices that cannot communicate using p2pdma will return - * PCI_P2PDMA_MAP_NOT_SUPPORTED. - * - * Any two devices that have a data path that goes through the host bridge - * will consult a whitelist. If the host bridges are on the whitelist, - * this function will return PCI_P2PDMA_MAP_THRU_HOST_BRIDGE. - * - * If either bridge is not on the whitelist this function returns - * PCI_P2PDMA_MAP_NOT_SUPPORTED. - * - * If a bridge which has any ACS redirection bits set is in the path, - * acs_redirects will be set to true. In this case, a list of all infringing - * bridge addresses will be populated in acs_list (assuming it's non-null) - * for printk purposes. - */ static enum pci_p2pdma_map_type -upstream_bridge_distance(struct pci_dev *provider, struct pci_dev *client, +__upstream_bridge_distance(struct pci_dev *provider, struct pci_dev *client, int *dist, bool *acs_redirects, struct seq_buf *acs_list) { struct pci_dev *a = provider, *b = client, *bb; @@ -416,6 +377,53 @@ upstream_bridge_distance(struct pci_dev *provider, struct pci_dev *client, return PCI_P2PDMA_MAP_BUS_ADDR; } +/* + * Find the distance through the nearest common upstream bridge between + * two PCI devices. + * + * If the two devices are the same device then 0 will be returned. + * + * If there are two virtual functions of the same device behind the same + * bridge port then 2 will be returned (one step down to the PCIe switch, + * then one step back to the same device). + * + * In the case where two devices are connected to the same PCIe switch, the + * value 4 will be returned. This corresponds to the following PCI tree: + * + * -+ Root Port + * \+ Switch Upstream Port + * +-+ Switch Downstream Port + * + \- Device A + * \-+ Switch Downstream Port + * \- Device B + * + * The distance is 4 because we traverse from Device A through the downstream + * port of the switch, to the common upstream port, back up to the second + * downstream port and then to Device B. + * + * Any two devices that cannot communicate using p2pdma will return + * PCI_P2PDMA_MAP_NOT_SUPPORTED. + * + * Any two devices that have a data path that goes through the host bridge + * will consult a whitelist. If the host bridges are on the whitelist, + * this function will return PCI_P2PDMA_MAP_THRU_HOST_BRIDGE. + * + * If either bridge is not on the whitelist this function returns + * PCI_P2PDMA_MAP_NOT_SUPPORTED. + * + * If a bridge which has any ACS redirection bits set is in the path, + * acs_redirects will be set to true. In this case, a list of all infringing + * bridge addresses will be populated in acs_list (assuming it's non-null) + * for printk purposes. + */ +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) +{ + return __upstream_bridge_distance(provider, client, dist, + acs_redirects, acs_list); +} + static enum pci_p2pdma_map_type upstream_bridge_distance_warn(struct pci_dev *provider, struct pci_dev *client, int *dist) -- 2.20.1
