diff options
Diffstat (limited to 'drivers/pci/hotplug/pciehp_pci.c')
| -rw-r--r-- | drivers/pci/hotplug/pciehp_pci.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c new file mode 100644 index 000000000..ad12515a4 --- /dev/null +++ b/drivers/pci/hotplug/pciehp_pci.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * PCI Express Hot Plug Controller Driver + * + * Copyright (C) 1995,2001 Compaq Computer Corporation + * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com) + * Copyright (C) 2001 IBM Corp. + * Copyright (C) 2003-2004 Intel Corporation + * + * All rights reserved. + * + * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com> + * + */ + +#define dev_fmt(fmt) "pciehp: " fmt + +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/pci.h> +#include "../pci.h" +#include "pciehp.h" + +/** + * pciehp_configure_device() - enumerate PCI devices below a hotplug bridge + * @ctrl: PCIe hotplug controller + * + * Enumerate PCI devices below a hotplug bridge and add them to the system. + * Return 0 on success, %-EEXIST if the devices are already enumerated or + * %-ENODEV if enumeration failed. + */ +int pciehp_configure_device(struct controller *ctrl) +{ + struct pci_dev *dev; + struct pci_dev *bridge = ctrl->pcie->port; + struct pci_bus *parent = bridge->subordinate; + int num, ret = 0; + + pci_lock_rescan_remove(); + + dev = pci_get_slot(parent, PCI_DEVFN(0, 0)); + if (dev) { + /* + * The device is already there. Either configured by the + * boot firmware or a previous hotplug event. + */ + ctrl_dbg(ctrl, "Device %s already exists at %04x:%02x:00, skipping hot-add\n", + pci_name(dev), pci_domain_nr(parent), parent->number); + pci_dev_put(dev); + ret = -EEXIST; + goto out; + } + + num = pci_scan_slot(parent, PCI_DEVFN(0, 0)); + if (num == 0) { + ctrl_err(ctrl, "No new device found\n"); + ret = -ENODEV; + goto out; + } + + for_each_pci_bridge(dev, parent) + pci_hp_add_bridge(dev); + + pci_assign_unassigned_bridge_resources(bridge); + pcie_bus_configure_settings(parent); + + /* + * Release reset_lock during driver binding + * to avoid AB-BA deadlock with device_lock. + */ + up_read(&ctrl->reset_lock); + pci_bus_add_devices(parent); + down_read_nested(&ctrl->reset_lock, ctrl->depth); + + out: + pci_unlock_rescan_remove(); + return ret; +} + +/** + * pciehp_unconfigure_device() - remove PCI devices below a hotplug bridge + * @ctrl: PCIe hotplug controller + * @presence: whether the card is still present in the slot; + * true for safe removal via sysfs or an Attention Button press, + * false for surprise removal + * + * Unbind PCI devices below a hotplug bridge from their drivers and remove + * them from the system. Safely removed devices are quiesced. Surprise + * removed devices are marked as such to prevent further accesses. + */ +void pciehp_unconfigure_device(struct controller *ctrl, bool presence) +{ + struct pci_dev *dev, *temp; + struct pci_bus *parent = ctrl->pcie->port->subordinate; + u16 command; + + ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n", + __func__, pci_domain_nr(parent), parent->number); + + if (!presence) + pci_walk_bus(parent, pci_dev_set_disconnected, NULL); + + pci_lock_rescan_remove(); + + /* + * Stopping an SR-IOV PF device removes all the associated VFs, + * which will update the bus->devices list and confuse the + * iterator. Therefore, iterate in reverse so we remove the VFs + * first, then the PF. We do the same in pci_stop_bus_device(). + */ + list_for_each_entry_safe_reverse(dev, temp, &parent->devices, + bus_list) { + pci_dev_get(dev); + + /* + * Release reset_lock during driver unbinding + * to avoid AB-BA deadlock with device_lock. + */ + up_read(&ctrl->reset_lock); + pci_stop_and_remove_bus_device(dev); + down_read_nested(&ctrl->reset_lock, ctrl->depth); + + /* + * Ensure that no new Requests will be generated from + * the device. + */ + if (presence) { + pci_read_config_word(dev, PCI_COMMAND, &command); + command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR); + command |= PCI_COMMAND_INTX_DISABLE; + pci_write_config_word(dev, PCI_COMMAND, command); + } + pci_dev_put(dev); + } + + pci_unlock_rescan_remove(); +} |