From 9e884897aa8c813b0074e1c5d129fdac45d4029f Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Mon, 27 Jul 2020 11:10:37 -0400 Subject: [PATCH 1973/2944] PCI: Simplify disconnected marking task #29600094 commit a50ac6bfd6042b16e0de4ac3264c407e678c9b10 upstream. Backport summary: for 4.19 kernel ICX PCIe Gen4 support. Commit 89ee9f768003 ("PCI: Add device disconnected state") iterates over the devices on a parent bus, marks each as disconnected, then marks each device's children as disconnected using pci_walk_bus(). The same can be achieved more succinctly by calling pci_walk_bus() on the parent bus. Moreover, this does not need to wait until acquiring pci_lock_rescan_remove(), so move it out of that critical section. The critical section in err.c contains a pci_dev_get() / pci_dev_put() pair which was apparently copy-pasted from pciehp_pci.c. In the latter it serves the purpose of holding the struct pci_dev in place until the Command register is updated. err.c doesn't do anything like that, hence the pair is unnecessary. Remove it. Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Cc: Keith Busch Cc: Oza Pawandeep Cc: Sinan Kaya Cc: Benjamin Herrenschmidt (cherry picked from commit a50ac6bfd6042b16e0de4ac3264c407e678c9b10) Signed-off-by: Ethan Zhao Signed-off-by: Artie Ding Acked-by: Caspar Zhang --- drivers/pci/hotplug/pciehp_pci.c | 9 +++------ drivers/pci/pcie/err.c | 8 ++------ 2 files changed, 5 insertions(+), 12 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c index 5c58c22..3ef5c07 100644 --- a/drivers/pci/hotplug/pciehp_pci.c +++ b/drivers/pci/hotplug/pciehp_pci.c @@ -74,6 +74,9 @@ void pciehp_unconfigure_device(struct slot *p_slot) __func__, pci_domain_nr(parent), parent->number); pciehp_get_adapter_status(p_slot, &presence); + if (!presence) + pci_walk_bus(parent, pci_dev_set_disconnected, NULL); + pci_lock_rescan_remove(); /* @@ -85,12 +88,6 @@ void pciehp_unconfigure_device(struct slot *p_slot) list_for_each_entry_safe_reverse(dev, temp, &parent->devices, bus_list) { pci_dev_get(dev); - if (!presence) { - pci_dev_set_disconnected(dev, NULL); - if (pci_has_subordinate(dev)) - pci_walk_bus(dev->subordinate, - pci_dev_set_disconnected, NULL); - } pci_stop_and_remove_bus_device(dev); /* * Ensure that no new Requests will be generated from diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c index 2c3b5bd..dee5a75 100644 --- a/drivers/pci/pcie/err.c +++ b/drivers/pci/pcie/err.c @@ -239,17 +239,13 @@ void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service) udev = dev->bus->self; parent = udev->subordinate; + pci_walk_bus(parent, pci_dev_set_disconnected, NULL); + pci_lock_rescan_remove(); pci_dev_get(dev); list_for_each_entry_safe_reverse(pdev, temp, &parent->devices, bus_list) { - pci_dev_get(pdev); - pci_dev_set_disconnected(pdev, NULL); - if (pci_has_subordinate(pdev)) - pci_walk_bus(pdev->subordinate, - pci_dev_set_disconnected, NULL); pci_stop_and_remove_bus_device(pdev); - pci_dev_put(pdev); } result = reset_link(udev, service); -- 1.8.3.1