From: Manivannan Sadhasivam <[email protected]> Some host bridge devices require resetting the Root Ports in a platform specific way to recover them from error conditions such as Fatal AER errors, Link Down etc... So introduce pci_host_bridge::reset_root_port() callback and call it from pcibios_reset_secondary_bus() if available. Also, save the Root Port config space before reset and restore it afterwards.
The 'reset_root_port' callback is responsible for resetting the given Root Port referenced by the 'pci_dev' pointer in a platform specific way and bring it back to the working state if possible. If any error occurs during the reset operation, relevant errno should be returned. Signed-off-by: Manivannan Sadhasivam <[email protected]> Signed-off-by: Manivannan Sadhasivam <[email protected]> Tested-by: Brian Norris <[email protected]> Tested-by: Krishna Chaitanya Chundru <[email protected]> Tested-by: Richard Zhu <[email protected]> Reviewed-by: Frank Li <[email protected]> --- drivers/pci/pci.c | 20 ++++++++++++++++++++ drivers/pci/pcie/err.c | 5 ----- include/linux/pci.h | 1 + 3 files changed, 21 insertions(+), 5 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 8479c2e1f74f..6f09057d83e0 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4812,6 +4812,26 @@ void pci_reset_secondary_bus(struct pci_dev *dev) void __weak pcibios_reset_secondary_bus(struct pci_dev *dev) { + struct pci_host_bridge *host = pci_find_host_bridge(dev->bus); + int ret; + + if (pci_is_root_bus(dev->bus) && host->reset_root_port) { + /* + * Save the config space of the Root Port before doing the + * reset, since the state could be lost. The Endpoint state + * should've been saved by the caller. + */ + pci_save_state(dev); + ret = host->reset_root_port(host, dev); + if (ret) + pci_err(dev, "Failed to reset Root Port: %d\n", ret); + else + /* Now restore it on success */ + pci_restore_state(dev); + + return; + } + pci_reset_secondary_bus(dev); } diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c index bebe4bc111d7..13b9d9eb714f 100644 --- a/drivers/pci/pcie/err.c +++ b/drivers/pci/pcie/err.c @@ -256,11 +256,6 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, } if (status == PCI_ERS_RESULT_NEED_RESET) { - /* - * TODO: Should call platform-specific - * functions to reset slot before calling - * drivers' slot_reset callbacks? - */ status = PCI_ERS_RESULT_RECOVERED; pci_dbg(bridge, "broadcast slot_reset message\n"); pci_walk_bridge(bridge, report_slot_reset, &status); diff --git a/include/linux/pci.h b/include/linux/pci.h index 1c270f1d5123..34c434b79abb 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -644,6 +644,7 @@ struct pci_host_bridge { void (*release_fn)(struct pci_host_bridge *); int (*enable_device)(struct pci_host_bridge *bridge, struct pci_dev *dev); void (*disable_device)(struct pci_host_bridge *bridge, struct pci_dev *dev); + int (*reset_root_port)(struct pci_host_bridge *bridge, struct pci_dev *dev); void *release_data; unsigned int ignore_reset_delay:1; /* For entire hierarchy */ unsigned int no_ext_tags:1; /* No Extended Tags */ -- 2.51.0
