From 3b3dcd61fa4e3604d8f1bdfd8471fca7b7c012e4 Mon Sep 17 00:00:00 2001 From: Philippe Bergheaud Date: Fri, 1 Jul 2016 13:32:52 +0200 Subject: [PATCH] cxl: Ignore CAPI adapters misplaced in switched slots One should not attempt to switch a PHB into CAPI mode if there is a switch between the PHB and the adapter. This patch modifies the cxl driver to ignore CAPI adapters misplaced in switched slots. Signed-off-by: Philippe Bergheaud Reviewed-by: Frederic Barrat Acked-by: Ian Munsie Signed-off-by: Michael Ellerman --- drivers/misc/cxl/pci.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index b7f2e96c1528..3a5f9801640d 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -1402,6 +1402,30 @@ static void cxl_pci_remove_adapter(struct cxl *adapter) device_unregister(&adapter->dev); } +#define CXL_MAX_PCIEX_PARENT 2 + +static int cxl_slot_is_switched(struct pci_dev *dev) +{ + struct device_node *np; + int depth = 0; + const __be32 *prop; + + if (!(np = pci_device_to_OF_node(dev))) { + pr_err("cxl: np = NULL\n"); + return -ENODEV; + } + of_node_get(np); + while (np) { + np = of_get_next_parent(np); + prop = of_get_property(np, "device_type", NULL); + if (!prop || strcmp((char *)prop, "pciex")) + break; + depth++; + } + of_node_put(np); + return (depth > CXL_MAX_PCIEX_PARENT); +} + static int cxl_probe(struct pci_dev *dev, const struct pci_device_id *id) { struct cxl *adapter; @@ -1413,6 +1437,11 @@ static int cxl_probe(struct pci_dev *dev, const struct pci_device_id *id) return -ENODEV; } + if (cxl_slot_is_switched(dev)) { + dev_info(&dev->dev, "Ignoring card on incompatible PCI slot\n"); + return -ENODEV; + } + if (cxl_verbose) dump_cxl_config_space(dev); -- 2.39.5