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       1                 :            : // SPDX-License-Identifier: GPL-2.0+
       2                 :            : /*
       3                 :            :  * PCI Express Hot Plug Controller Driver
       4                 :            :  *
       5                 :            :  * Copyright (C) 1995,2001 Compaq Computer Corporation
       6                 :            :  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
       7                 :            :  * Copyright (C) 2001 IBM Corp.
       8                 :            :  * Copyright (C) 2003-2004 Intel Corporation
       9                 :            :  *
      10                 :            :  * All rights reserved.
      11                 :            :  *
      12                 :            :  * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
      13                 :            :  *
      14                 :            :  */
      15                 :            : 
      16                 :            : #define dev_fmt(fmt) "pciehp: " fmt
      17                 :            : 
      18                 :            : #include <linux/kernel.h>
      19                 :            : #include <linux/types.h>
      20                 :            : #include <linux/pci.h>
      21                 :            : #include "../pci.h"
      22                 :            : #include "pciehp.h"
      23                 :            : 
      24                 :            : /**
      25                 :            :  * pciehp_configure_device() - enumerate PCI devices below a hotplug bridge
      26                 :            :  * @ctrl: PCIe hotplug controller
      27                 :            :  *
      28                 :            :  * Enumerate PCI devices below a hotplug bridge and add them to the system.
      29                 :            :  * Return 0 on success, %-EEXIST if the devices are already enumerated or
      30                 :            :  * %-ENODEV if enumeration failed.
      31                 :            :  */
      32                 :          0 : int pciehp_configure_device(struct controller *ctrl)
      33                 :            : {
      34                 :          0 :         struct pci_dev *dev;
      35                 :          0 :         struct pci_dev *bridge = ctrl->pcie->port;
      36                 :          0 :         struct pci_bus *parent = bridge->subordinate;
      37                 :          0 :         int num, ret = 0;
      38                 :            : 
      39                 :          0 :         pci_lock_rescan_remove();
      40                 :            : 
      41                 :          0 :         dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
      42         [ #  # ]:          0 :         if (dev) {
      43                 :            :                 /*
      44                 :            :                  * The device is already there. Either configured by the
      45                 :            :                  * boot firmware or a previous hotplug event.
      46                 :            :                  */
      47                 :          0 :                 ctrl_dbg(ctrl, "Device %s already exists at %04x:%02x:00, skipping hot-add\n",
      48                 :            :                          pci_name(dev), pci_domain_nr(parent), parent->number);
      49                 :          0 :                 pci_dev_put(dev);
      50                 :          0 :                 ret = -EEXIST;
      51                 :          0 :                 goto out;
      52                 :            :         }
      53                 :            : 
      54                 :          0 :         num = pci_scan_slot(parent, PCI_DEVFN(0, 0));
      55         [ #  # ]:          0 :         if (num == 0) {
      56                 :          0 :                 ctrl_err(ctrl, "No new device found\n");
      57                 :          0 :                 ret = -ENODEV;
      58                 :          0 :                 goto out;
      59                 :            :         }
      60                 :            : 
      61   [ #  #  #  # ]:          0 :         for_each_pci_bridge(dev, parent)
      62                 :          0 :                 pci_hp_add_bridge(dev);
      63                 :            : 
      64                 :          0 :         pci_assign_unassigned_bridge_resources(bridge);
      65                 :          0 :         pcie_bus_configure_settings(parent);
      66                 :          0 :         pci_bus_add_devices(parent);
      67                 :            : 
      68                 :          0 :  out:
      69                 :          0 :         pci_unlock_rescan_remove();
      70                 :          0 :         return ret;
      71                 :            : }
      72                 :            : 
      73                 :            : /**
      74                 :            :  * pciehp_unconfigure_device() - remove PCI devices below a hotplug bridge
      75                 :            :  * @ctrl: PCIe hotplug controller
      76                 :            :  * @presence: whether the card is still present in the slot;
      77                 :            :  *      true for safe removal via sysfs or an Attention Button press,
      78                 :            :  *      false for surprise removal
      79                 :            :  *
      80                 :            :  * Unbind PCI devices below a hotplug bridge from their drivers and remove
      81                 :            :  * them from the system.  Safely removed devices are quiesced.  Surprise
      82                 :            :  * removed devices are marked as such to prevent further accesses.
      83                 :            :  */
      84                 :          0 : void pciehp_unconfigure_device(struct controller *ctrl, bool presence)
      85                 :            : {
      86                 :          0 :         struct pci_dev *dev, *temp;
      87                 :          0 :         struct pci_bus *parent = ctrl->pcie->port->subordinate;
      88                 :          0 :         u16 command;
      89                 :            : 
      90                 :          0 :         ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n",
      91                 :            :                  __func__, pci_domain_nr(parent), parent->number);
      92                 :            : 
      93         [ #  # ]:          0 :         if (!presence)
      94                 :          0 :                 pci_walk_bus(parent, pci_dev_set_disconnected, NULL);
      95                 :            : 
      96                 :          0 :         pci_lock_rescan_remove();
      97                 :            : 
      98                 :            :         /*
      99                 :            :          * Stopping an SR-IOV PF device removes all the associated VFs,
     100                 :            :          * which will update the bus->devices list and confuse the
     101                 :            :          * iterator.  Therefore, iterate in reverse so we remove the VFs
     102                 :            :          * first, then the PF.  We do the same in pci_stop_bus_device().
     103                 :            :          */
     104         [ #  # ]:          0 :         list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
     105                 :            :                                          bus_list) {
     106                 :          0 :                 pci_dev_get(dev);
     107                 :          0 :                 pci_stop_and_remove_bus_device(dev);
     108                 :            :                 /*
     109                 :            :                  * Ensure that no new Requests will be generated from
     110                 :            :                  * the device.
     111                 :            :                  */
     112         [ #  # ]:          0 :                 if (presence) {
     113                 :          0 :                         pci_read_config_word(dev, PCI_COMMAND, &command);
     114                 :          0 :                         command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR);
     115                 :          0 :                         command |= PCI_COMMAND_INTX_DISABLE;
     116                 :          0 :                         pci_write_config_word(dev, PCI_COMMAND, command);
     117                 :            :                 }
     118                 :          0 :                 pci_dev_put(dev);
     119                 :            :         }
     120                 :            : 
     121                 :          0 :         pci_unlock_rescan_remove();
     122                 :          0 : }